JP5625638B2 - In-wheel motor - Google Patents

Description

  The present invention relates to an in-wheel motor that drives an electric vehicle.

  Among the electric vehicle driving devices, those that directly drive the wheels are called in-wheel motors. An in-wheel motor here is a drive device provided in the vicinity of the wheel with which an electric vehicle is equipped. Note that the in-wheel motor is not necessarily housed in the wheel. The in-wheel motor needs to be arranged inside the wheel or in the vicinity of the wheel. However, the interior of the wheel and the vicinity of the wheel are relatively narrow spaces. Therefore, the in-wheel motor is required to be downsized.

  There are two types of in-wheel motors, one with a reduction mechanism and the other with a direct drive method without a reduction mechanism. An in-wheel motor having a speed reduction mechanism easily secures a sufficient rotational force to drive an electric vehicle when the electric vehicle starts or climbs (when climbing a hill). However, since the in-wheel motor of a system provided with a speed reduction mechanism transmits a rotational force to the wheel via the speed reduction mechanism, friction loss occurs in the speed reduction mechanism. In an in-wheel motor provided with a speed reduction mechanism, the rotational speed of the output shaft of the motor is always faster than the rotational speed of the wheel. Therefore, in an in-wheel motor having a speed reduction mechanism, energy loss increases due to friction loss in the speed reduction mechanism, particularly when the electric vehicle travels at a high speed.

  On the other hand, the direct drive type in-wheel motor transmits the rotational force to the wheel without going through the speed reduction mechanism, so that energy loss can be reduced. However, the direct drive type in-wheel motor cannot amplify the rotational force by the speed reduction mechanism. As a result, the direct drive in-wheel motor is difficult to ensure sufficient rotational force to drive the electric vehicle when the electric vehicle starts or climbs. As a technique for ensuring a sufficient rotational force for driving an electric vehicle, for example, Patent Document 1 discloses a technique that is not an in-wheel motor, but includes a speed reduction mechanism including a planetary gear mechanism and two motors. Is disclosed.

Japanese Patent Laid-Open No. 2005-081932

  The technique disclosed in Patent Document 1 has a power circulation path. The technique disclosed in Patent Document 1 first converts a rotational force into electric power in a power circulation path, and converts the electric power into rotational force again. Therefore, the technique disclosed in Patent Document 1 needs to include a generator and a motor in the power circulation path. However, as described above, the in-wheel motor is required to reduce the size of the electric vehicle drive device, and it is difficult to secure a space for installing the generator and the motor near the wheel. Moreover, the technique currently disclosed by patent document 1 converts motive power into electric power, and also converts electric power into motive power. Therefore, the technique disclosed in Patent Document 1 causes energy loss during energy conversion.

  On the other hand, when the clutch device is included in the deceleration mechanism of the in-wheel motor, the maximum torque that the in-wheel motor can output may be limited by the torque (rotational force) capacity of the clutch device.

  The present invention has been made in view of the above, and an object of the present invention is to provide an in-wheel motor that can secure sufficient rotational force to drive an electric vehicle and can reduce energy loss.

  In order to solve the above-described problems and achieve the object, an in-wheel motor according to a first invention includes a first motor, a second motor, and a first sun gear coupled to the first motor, A first pinion gear meshing with the first sun gear and the first pinion gear are held so that the first pinion gear can rotate and the first pinion gear can revolve around the first sun gear. A first carrier, a first member, a second member that can rotate relative to the first member, and a rotational force in a first direction acting on the second member, between the first member and the second member. A plurality of sprags that transmit a rotational force between the first member and the second member when a rotational force in a second direction opposite to the first direction acts on the second member. The rotation of the first carrier A clutch device that can be controlled, a first ring gear that meshes with the first pinion gear and that is coupled to the second motor, a second sun gear that is coupled to the first motor, and a second gear that meshes with the second sun gear. A second pinion gear, a third pinion gear meshing with the second pinion gear, the second pinion gear, and the third pinion gear so that they can rotate, and the second pinion gear and the third pinion gear are Holding the second pinion gear and the third pinion gear so as to revolve around the second sun gear, meshing with the second carrier coupled to the first ring gear, and the third pinion gear; and A second ring gear coupled to a wheel of the electric vehicle, wherein the first direction is configured to move the electric vehicle forward. Over data outputs a rotational force, and the second member is characterized in that the direction of rotation when the second motor is not operating.

  With the above configuration, the in-wheel motor according to the first aspect of the present invention can realize two shift states, a first shift state and a second shift state. In the first speed change state, the first motor operates, the second motor does not operate, and the clutch device is in the engaged state. In the first speed change state, the in-wheel motor according to the first aspect of the invention has a part of the rotational force returned from the second carrier to the first ring gear, and the rotational force transmitted to the first ring gear is transmitted via the first sun gear. To the second sun gear. That is, in the in-wheel motor according to the first invention, the rotational force circulates. Thereby, the in-wheel motor which concerns on 1st invention can implement | achieve a bigger gear ratio. That is, the in-wheel motor according to the first aspect of the invention can transmit a rotational force larger than the rotational force output by the first motor to the wheel when in the first speed change state.

  In the second speed change state, the first motor and the second motor operate, and the clutch device is in a non-engagement state. The in-wheel motor which concerns on 1st invention can change a gear ratio continuously by changing the angular velocity of the rotational force output from a 2nd motor in the 2nd speed change state. Thereby, the in-wheel motor which concerns on 1st invention can reduce the difference of the angular velocity of a 1st motor, and the angular velocity of the 2nd ring gear used as an output shaft. Thereby, the in-wheel motor which concerns on 1st invention can reduce a friction loss.

  In addition, when the clutch device has a first member, a second member that can rotate with respect to the first member, and a rotational force in a first direction acting on the second member, the first member and the second member A plurality of members that transmit a rotational force between the first member and the second member when a rotational force in a second direction opposite to the first direction acts on the second member. In the first direction, the first motor outputs a rotational force so as to move the electric vehicle forward, and the second member is operated when the second motor is not operated. By being the structure which is a direction to rotate, the direction of the rotational force which acts on a 2nd member can be switched, and an engagement state and a non-engagement state can be switched. Therefore, a mechanism for moving the piston and an electromagnetic actuator are not required. Thereby, the in-wheel motor which concerns on this invention can reduce a number of parts, and can miniaturize itself (clutch apparatus). Further, a mechanism for moving the piston and energy for operating the electromagnetic actuator are not required.

  Further, since the clutch device uses sprags as the friction engagement members, a larger number of sprags can be arranged between the first member and the second member than the number of columnar cams. Therefore, the torque capacity of the clutch device can be made larger than that of the cam clutch device having a cylindrical cam. As a result, since the magnitude of the force that can be transmitted between the first member and the second member becomes larger, the maximum value of the rotational force output to the wheel can be set large.

  In order to solve the above-described problems and achieve the object, an in-wheel motor according to a second invention includes a first motor, a second motor, and a first sun gear coupled to the first motor, A first pinion gear meshing with the first sun gear and the first pinion gear are held so that the first pinion gear can rotate and the first pinion gear can revolve around the first sun gear. A first ring gear meshing with the first carrier, the first pinion gear and coupled to the wheel of the electric vehicle, a second sun gear coupled to the first motor, and a second meshing mesh with the second sun gear. A pinion gear, a third pinion gear that meshes with the second pinion gear, the second pinion gear, and the third pinion gear so that each of them can rotate, and A second carrier for holding the second pinion gear and the third pinion gear, a first member, and the first member so that the pinion gear and the third pinion gear can revolve around the second sun gear. When the rotational force in the first direction acts on the second member that can rotate and the second member, the rotational force is transmitted between the first member and the second member, and the first direction is transmitted to the second member. A clutch device that includes a plurality of sprags that do not transmit a rotational force between the first member and the second member when a rotational force in a second direction opposite to that acts, and that can restrict the rotation of the second carrier; A second ring gear meshing with the third pinion gear, coupled to the first carrier, and coupled to the second motor, wherein the first direction advances the electric vehicle. The first mode There outputs a rotational force, and the second member is characterized in that the direction of rotation when the second motor is not operating.

  With the above configuration, the in-wheel motor according to the second aspect of the present invention can realize two shift states, a first shift state and a second shift state. In the first speed change state, the first motor operates, the second motor does not operate, and the clutch device is in the engaged state. In the first speed change state, the in-wheel motor according to the second invention has a part of the rotational force returned from the first carrier to the second ring gear, and further the rotational force transmitted to the second ring gear is transmitted via the second sun gear. To the first sun gear. That is, in the in-wheel motor according to the second invention, the rotational force circulates. Thereby, the in-wheel motor which concerns on 2nd invention can implement | achieve a bigger gear ratio. That is, the in-wheel motor according to the second aspect of the invention can transmit a rotational force larger than the rotational force output by the first motor to the wheel when in the first speed change state.

  In the second speed change state, the first motor and the second motor operate, and the clutch device is in a non-engagement state. The in-wheel motor which concerns on 2nd invention can change a gear ratio continuously by changing the angular velocity of the rotational force output from a 2nd motor in the 2nd speed change state. Thereby, the in-wheel motor which concerns on 2nd invention can reduce the difference of the angular velocity of a 1st motor, and the angular velocity of the 1st ring gear used as an output shaft. Thereby, the in-wheel motor which concerns on 2nd invention can reduce a friction loss.

  The in-wheel motor according to the present invention is characterized in that the clutch device includes an elastic member that makes the sprag contact the first member and the second member. Thereby, the time required for the clutch device to switch from the non-engaged state to the engaged state can be reduced.

  The in-wheel motor according to the present invention is characterized in that the clutch device includes a first cage and a second cage that hold the plurality of sprags at equal intervals. As a result, the total torque acting on the clutch device is divided equally and acts on each sprag. Therefore, the torque capacity of the clutch device according to the present invention can be further increased compared to a clutch device that does not include a cage.

  In a preferred aspect of the present invention, the first cage is a cylinder having a plurality of first openings arranged at equal intervals on the side surface, and the second cage is equally spaced from each other. A cylinder having the same number of second openings as the first retainer on its side surface, the outer diameter of which is smaller than the inner diameter of the first retainer, and the first opening and the The second holder is disposed inside the first holder so that the second opening is opposed to the first opening, and the first opening and the second opening are opposed to each other. It is desirable to insert a sprag.

  In a preferred aspect of the first invention, the ratio between the second rotational force output by the second motor and the first rotational force output by the first motor is determined by the second sun gear and the second carrier. It is desirable that it is 82% or more of the rotational force ratio acting during the period.

  The in-wheel motor according to the first aspect of the invention includes TA, which is the rotational force output from the first motor, TB, which is the rotational force output from the second motor, the number of teeth Z1 of the second sun gear, and the second ring. The gear tooth number Z4 needs to satisfy the following formula (7) described later. However, the rotational force output from the motor has an error of about 18% at maximum with respect to the design value due to factors such as the size of the motor and magnetic characteristics. The in-wheel motor which concerns on the preferable aspect of the said 1st invention is TA which is the rotational force which a 1st motor outputs, and TB which is the rotational force which a 2nd motor outputs regardless of an individual difference by the said structure. The number of teeth Z1 of the second sun gear and the number of teeth Z4 of the second ring gear can satisfy the following formula (7).

  In a preferred aspect of the second invention, the ratio between the second rotational force output by the second motor and the first rotational force output by the first motor is determined by the first sun gear and the first carrier. It is desirable that it is 82% or more of the rotational force ratio acting during the period. With the above configuration, the in-wheel motor according to a preferred aspect of the second invention has a TA that is a rotational force output by the first motor and a TB that is a rotational force output by the second motor, regardless of individual differences. The number of teeth Z5 of the first sun gear and the number of teeth Z7 of the first ring gear can satisfy the following formula (8) described later.

  As a preferred aspect of the present invention, a cross-sectional shape obtained by cutting the stator core of the first motor along a plane orthogonal to the rotation axis of the first motor, and a plane orthogonal to the rotation axis of the second motor. It is desirable that the sectional shape of the stator core is the same.

  In the in-wheel motor according to the present invention, the design of the stator core is common between the first motor and the second motor with the above-described configuration, so that the labor required for the design can be reduced. When the cross-sectional shape of the stator core of the first motor and the cross-sectional shape of the stator core of the second motor are the same, the stator core of the first motor and the second stator core of the second motor are manufactured with the same mold. Can do. Therefore, the in-wheel motor according to the present invention can reduce labor required for manufacturing. Moreover, the in-wheel motor which concerns on this invention can reduce the cost which manufacture requires.

  As a preferable aspect of the first invention, a ratio between a dimension of the stator core of the first motor in the rotation axis direction of the first motor and a dimension of the stator core of the second motor in the rotation axis direction of the second motor. Is preferably 82% or more and 118% or less of the rotational force ratio acting between the second sun gear and the second carrier. Further, as a preferred aspect of the second invention, the dimension of the stator core of the first motor in the rotation axis direction of the first motor and the dimension of the stator core of the second motor in the rotation axis direction of the second motor The ratio is desirably 82% or more and 118% or less of a rotational force ratio acting between the first sun gear and the first carrier.

  When the cross-sectional shape of the stator core is the same, the magnitude of the rotational force output by the motor is proportional to the dimension of the stator core in the direction of the rotation axis. Therefore, the in-wheel motor according to a preferred aspect of the first invention has the above-described configuration, TA that is the rotational force output by the first motor, TB that is the rotational force output by the second motor, and the second sun gear. The number of teeth Z1 and the number of teeth Z4 of the second ring gear can satisfy the above formula (7). Moreover, the in-wheel motor which concerns on the preferable aspect of the said 2nd invention is based on the said structure, TA which is the rotational force which a 1st motor outputs, TB which is the rotational force which a 2nd motor outputs, 1st sun gear The number of teeth Z5 and the number of teeth Z7 of the first ring gear can satisfy the above formula (8).

  As a preferred aspect of the present invention, a cross-sectional shape obtained by cutting the rotor core of the first motor in a plane orthogonal to the rotation axis of the first motor, and a plane orthogonal to the rotation axis of the second motor. It is desirable that the cross-sectional shape of the rotor core cut is the same.

  The in-wheel motor according to the present invention has the above-described configuration, and the first motor and the second motor share the same rotor core design. Therefore, the labor required for the design can be reduced. Further, when the cross-sectional shape of the rotor core of the first motor and the cross-sectional shape of the rotor core of the second motor are the same, the rotor core of the first motor and the second rotor core of the second motor are manufactured with the same mold. Can do. Therefore, the in-wheel motor according to the present invention can reduce labor required for manufacturing. Moreover, the in-wheel motor which concerns on this invention can reduce the cost which manufacture requires.

  As a preferred aspect of the present invention, the ratio of the dimension of the rotor core of the first motor in the rotation axis direction of the first motor to the dimension of the rotor core of the second motor in the rotation axis direction of the second motor is It is desirable that it is 82% or more and 118% or less of the rotational force ratio.

  When the cross-sectional shape of the rotor core is the same, the magnitude of the rotational force output by the motor is proportional to the dimension of the rotor core in the direction of the rotation axis. Therefore, the in-wheel motor according to a preferred aspect of the first invention has the above-described configuration, TA that is the rotational force output by the first motor, TB that is the rotational force output by the second motor, and the second sun gear. The number of teeth Z1 and the number of teeth Z4 of the second ring gear can satisfy the above formula (7). Moreover, the in-wheel motor which concerns on the preferable aspect of the said 2nd invention is based on the said structure, TA which is the rotational force which a 1st motor outputs, TB which is the rotational force which a 2nd motor outputs, 1st sun gear The number of teeth Z5 and the number of teeth Z7 of the first ring gear can satisfy the above formula (8).

  The present invention can provide an in-wheel motor that can secure a sufficient rotational force to drive an electric vehicle and can reduce energy loss.

FIG. 1 is an explanatory diagram illustrating a configuration of the electric vehicle drive device according to the first embodiment and a path through which a rotational force is transmitted when the electric vehicle drive device is in the first speed change state. FIG. 2 is a collinear diagram showing each rotational speed of each part when the electric vehicle drive device of the first embodiment is in the first speed change state. FIG. 3 is an explanatory diagram illustrating a path through which the rotational force is transmitted when the electric vehicle drive device of the first embodiment is in the second speed change state. FIG. 4 is a graph illustrating an example of angular velocity-rotational force characteristics of the first motor and the second motor according to the first embodiment. FIG. 5A is an exploded explanatory diagram of the clutch device of the first embodiment. FIG. 5B is an explanatory diagram of the clutch device according to the first embodiment. FIG. 6 is an explanatory view showing an enlarged sprag of the clutch device of the first embodiment. FIG. 7 is an explanatory diagram schematically illustrating the external appearance of the electric vehicle drive device according to the first embodiment. FIG. 8 is a cross-sectional view taken along the line AA of FIG. FIG. 9 is an explanatory view showing the electric vehicle drive device of Embodiment 1 in an exploded manner. FIG. 10 is a graph showing the appearance probability of individual differences in rotational force output by the motor. FIG. 11 is an explanatory diagram illustrating a configuration of the electric vehicle drive device according to the second embodiment. FIG. 12 is a collinear diagram showing the rotational speeds of the respective parts when the electric vehicle driving apparatus of the second embodiment is in the first shift state.

  Hereinafter, the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is not limited by the modes for carrying out the invention (hereinafter referred to as embodiments). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art and those that are substantially the same.

(Embodiment 1)
FIG. 1 is an explanatory diagram illustrating a configuration of the electric vehicle drive device according to the first embodiment and a path through which a rotational force is transmitted when the electric vehicle drive device is in the first speed change state. As shown in FIG. 1, the electric vehicle drive device 10 that is an in-wheel motor includes a casing G, a first motor 11, a second motor 12, a speed change mechanism 13, and a wheel bearing 50. The casing G houses the first motor 11, the second motor 12, and the speed change mechanism 13. The first motor 11 can output the first rotational force TA. The second motor 12 can output the second rotational force TB. The speed change mechanism 13 is connected to the first motor 11. Thereby, when the 1st motor 11 act | operates, the 1st rotational force TA will be transmitted to the transmission mechanism 13 (input). The operation of the motor here means that electric power is supplied to the motor and the output shaft rotates. The transmission mechanism 13 is connected to the second motor 12. Thereby, when the 2nd motor 12 act | operates, the 2nd rotational force TB will be transmitted to the transmission mechanism 13 (input). The speed change mechanism 13 is connected to the wheel bearing 50 and transmits (outputs) the changed rotational force to the wheel bearing 50. Wheel bearing 50 is attached to wheel H of the electric vehicle.

  The speed change mechanism 13 includes a first planetary gear mechanism 20, a second planetary gear mechanism 30, and a clutch device 40. The first planetary gear mechanism 20 is a single pinion type planetary gear mechanism. The first planetary gear mechanism 20 includes a first sun gear 21, a first pinion gear 22, a first carrier 23, and a first ring gear 24. The second planetary gear mechanism 30 is a double pinion planetary gear mechanism. The second planetary gear mechanism 30 includes a second sun gear 31, a second pinion gear 32a, a third pinion gear 32b, a second carrier 33, and a second ring gear 34.

  The first sun gear 21 is supported in the casing G so as to be able to rotate (spin) about the rotation axis R. The first sun gear 21 is connected to the first motor 11. Therefore, the first sun gear 21 receives the first rotational force TA when the first motor 11 is operated. As a result, the first sun gear 21 rotates about the rotation axis R when the first motor 11 is operated. The first pinion gear 22 meshes with the first sun gear 21. The first carrier 23 holds the first pinion gear 22 so that the first pinion gear 22 can rotate (rotate) about the first pinion rotation axis Rp1. The first pinion rotation axis Rp1 is, for example, parallel to the rotation axis R.

  The first carrier 23 is supported in the casing G so that it can rotate (rotate) about the rotation axis R. Thereby, the first carrier 23 holds the first pinion gear 22 so that the first pinion gear 22 can revolve around the first sun gear 21, that is, around the rotation axis R. The first ring gear 24 can rotate (spin) about the rotation axis R. The first ring gear 24 meshes with the first pinion gear 22. The first ring gear 24 is connected to the second motor 12. Accordingly, the first ring gear 24 transmits the second rotational force TB when the second motor 12 is operated. As a result, the first ring gear 24 rotates (rotates) around the rotation axis R when the second motor 12 is operated.

  The clutch device 40 can regulate the rotation of the first carrier 23. Specifically, the clutch device 40 can switch between restricting (braking) the rotation of the first carrier 23 around the rotation axis R and allowing the rotation. Hereinafter, in the clutch device 40, a state where the rotation is restricted (braking) is referred to as an engaged state, and a state where the rotation is allowed is referred to as a non-engaged state. Details of the clutch device 40 will be described later.

  The second sun gear 31 is supported in the casing G so as to rotate (spin) around the rotation axis R. The second sun gear 31 is connected to the first motor 11 via the first sun gear 21. Specifically, the first sun gear 21 and the second sun gear 31 are formed integrally with the sun gear shaft 14 so as to be rotatable on the same axis (rotation axis R). The sun gear shaft 14 is connected to the first motor 11. Thus, the second sun gear 31 rotates about the rotation axis R when the first motor 11 is operated.

  The second pinion gear 32 a meshes with the second sun gear 31. The third pinion gear 32b meshes with the second pinion gear 32a. The second carrier 33 holds the second pinion gear 32a so that the second pinion gear 32a can rotate (spin) about the second pinion rotation axis Rp2. The second carrier 33 holds the third pinion gear 32b so that the third pinion gear 32b can rotate (rotate) about the third pinion rotation axis Rp3. The second pinion rotation axis Rp2 and the third pinion rotation axis Rp3 are parallel to the rotation axis R, for example.

  The second carrier 33 is supported in the casing G so that it can rotate (rotate) about the rotation axis R. As a result, the second carrier 33 has the second pinion gear 32a and the third pinion gear 32a so that the second pinion gear 32a and the third pinion gear 32b can revolve around the second sun gear 31, that is, around the rotation axis R. 32b is held. The second carrier 33 is connected to the first ring gear 24. Thus, the second carrier 33 rotates (spins) about the rotation axis R when the first ring gear 24 rotates (spins). The second ring gear 34 can rotate (rotate) about the rotation axis R. The second ring gear 34 meshes with the third pinion gear 32b. The second ring gear 34 is connected to the wheel bearing 50. Accordingly, when the second ring gear 34 rotates (spins), the wheel bearing 50 rotates. Next, the transmission path of the rotational force in the electric vehicle drive device 10 will be described.

  The electric vehicle drive device 10 can realize two shift states, a first shift state and a second shift state. First, a description will be given of a case where the electric vehicle driving device 10 realizes a first shift state, that is, a so-called low gear state used when the electric vehicle starts or climbs (when climbing a hill). In the first speed change state, the first motor 11 operates. The rotational force output by the first motor 11 during the first speed change state is defined as a first rotational force T1. In the first speed change state, the second motor 12 does not operate, that is, idles. The clutch device 40 is in an engaged state. That is, in the first speed change state, the first pinion gear 22 cannot revolve with respect to the casing G. In addition, each rotational force of 1st rotational force T1, circulation rotational force T3, synthetic | combination rotational force T4, 1st distributed rotational force T5, and 2nd distributed rotational force T6 shown in FIG. 1 acts on each site | part. The unit is Nm.

  The first rotational force T <b> 1 output from the first motor 11 is input to the first sun gear 21. Then, the first rotational force T1 merges with the circulating rotational force T3 at the first sun gear 21. The circulating rotational force T3 is a rotational force transmitted from the first ring gear 24 to the first sun gear 21. Details of the circulating rotational force T3 will be described later. Thereby, the second sun gear 31 is transmitted with a combined rotational force T4 obtained by combining the first rotational force T1 and the circulating rotational force T3. The combined rotational force T4 is amplified by the second planetary gear mechanism 30. The combined rotational force T4 is distributed by the second planetary gear mechanism 30 to the first distributed rotational force T5 and the second distributed rotational force T6. The first distributed rotational force T5 is a rotational force distributed to the second ring gear 34. The second distributed rotational force T6 is a rotational force distributed to the second carrier 33.

  The first distributed rotational force T5 is transmitted from the second ring gear 34 to the wheel bearing 50. Thereby, the wheel H rotates and the electric vehicle travels. The second distributed rotational force T6 is input to the first planetary gear mechanism 20. Specifically, the second distributed rotational force T6 is transmitted to the first ring gear 24. The second distributed rotational force T6 is reduced by the first planetary gear mechanism 20. Specifically, the second distributed rotational force T6 is reduced by shifting when it is transmitted from the first ring gear 24 to the first sun gear 21 via the first pinion gear 22. Further, when the second distributed rotational force T6 is transmitted from the first ring gear 24 to the first sun gear 21 via the first pinion gear 22, the rotational direction of itself (second distributed rotational force T6) is reversed. Thus, the second distributed rotational force T6 is transmitted to the first sun gear 21 as a circulating rotational force T3.

  Thus, the first rotational force T1 input from the first motor 11 to the first sun gear 21 is amplified, and a part of the amplified rotational force is output as the first distributed rotational force T5. Then, the remaining rotational force of the amplified rotational force is transmitted from the second carrier 33 to the first sun gear 21 through the first ring gear 24 and the first pinion gear 22 as the circulating rotational force T3. The circulating rotational force T3 transmitted to the first sun gear 21 merges with the first rotational force T1 to become a combined rotational force T4 and is transmitted to the second sun gear 31.

  As described above, in the electric vehicle drive device 10, a part of the rotational force circulates between the first planetary gear mechanism 20 and the second planetary gear mechanism 30. Thereby, electric vehicle drive device 10 can realize a larger gear ratio. That is, the electric vehicle drive device 10 can transmit a larger rotational force to the wheel H in the first speed change state. Hereinafter, an example of values from the first rotational force T1 to the second distributed rotational force T6 will be described.

  The number of teeth of the second sun gear 31 is Z1, the number of teeth of the second ring gear 34 is Z4, the number of teeth of the first sun gear 21 is Z5, and the number of teeth of the first ring gear 24 is Z7. Hereinafter, the first rotational force T1 of the rotational force (circulating rotational force T3, combined rotational force T4, first distributed rotational force T5, second distributed rotational force T6 shown in FIG. 1) acting on each part of the electric vehicle drive device 10 will be described. The ratio to is shown by a mathematical expression. In addition, what becomes a negative value in the following formulas (1) to (4) is a rotational force in a direction opposite to the first rotational force T1.

  As an example, the number of teeth Z1 is 31, the number of teeth Z4 is 71, the number of teeth Z5 is 37, and the number of teeth Z7 is 71. Further, the first rotational force T1 is set to 75 Nm. Then, the circulating rotational force T3 is 154.0 Nm, the combined rotational force T4 is 229.0 Nm, the first distributed rotational force T5 is 524.4 Nm, and the second distributed rotational force T6 is -295.4 Nm. Thus, the electric vehicle drive apparatus 10 can amplify the 1st rotational force T1 which the 1st motor 11 outputs as an example by 6.99 times, and can output it to the wheel H. Next, the angular velocities of the respective parts in the first speed change state will be described using the nomograph.

  FIG. 2 is a collinear diagram showing each rotational speed of each part when the electric vehicle drive device of the first embodiment is in the first speed change state. Hereinafter, as an example, the angular velocity of the first sun gear 21 is set to V [rad / s]. Further, the negative angular velocity indicates that the rotation is in the direction opposite to the first rotational force TA. As shown in FIG. 2, the angular velocity of the first sun gear 21 is V [rad / s]. The rotation of the first carrier 23 is restricted by the clutch device 40. Therefore, the angular velocity of the first carrier 23 is 0 [rad / s]. The angular velocity of the first ring gear 24 is 0.521 V [rad / s]. The second sun gear 31 is connected to the first sun gear 21. Therefore, the angular velocity of the second sun gear 31 is V [rad / s]. The second carrier 33 is connected to the first ring gear 24. Therefore, the angular velocity of the second carrier 33 is 0.521 V [rad / s].

  Since the second planetary gear mechanism 30 is a double pinion planetary gear mechanism having two pinion gears, the rotational force transmitted from the second sun gear 31 to the second ring gear 34 is reversed by the second carrier 33. When the rotational force is transmitted from the second carrier 33 to the second ring gear 34, the rotational force is reversed and transmitted at a rate of change obtained by multiplying the rate of change when transmitted from the second sun gear 31 to the second carrier 33 by -1. That is, in FIG. 2, θ1 and θ2 are equal. As a result, the angular velocity of the second ring gear 34 is 0.143 V [rad / s]. As a result, the speed ratio of the speed change mechanism 13 is V / 0.143V = 6.99.

  Here, the counter torque acting on the first carrier 23 is − (second distributed rotational force T6 + (− circulating rotational force T3)), which is 449.4 Nm. All the counter torque acting on the first carrier 23 is held by the clutch mechanism 40. There is a limit to the torque that the clutch device 40 can hold, and when the torque exceeding the limit acts on the clutch device 40, the clutch device 40 slips. The first distributed rotational force T5 output to the wheel H increases in proportion to the first rotational force T1 that is the torque of the first motor 11, but the magnitude of the counter torque acting on the first carrier 23 is also the first. It increases in proportion to the rotational force T1. As a result, the first distributed rotational force T5 output to the wheel H is limited to the limit of torque that the clutch device 40 can hold. That is, in order to increase the maximum value of the first distributed rotational force T5 output to the wheel H, it is necessary not only to increase the torque of the first motor 11, but also to increase the torque capacity of the clutch device 40. In the present embodiment, the clutch device 40 is a sprag type one-way clutch device. Hereinafter, the clutch device 40 which is a sprag type one-way clutch device will be described.

  FIG. 5A is an exploded explanatory diagram illustrating the clutch device of the first embodiment. FIG. 5B is an explanatory diagram of the clutch device according to the first embodiment. FIG. 6 is an explanatory view showing an enlarged sprag of the clutch device of the first embodiment. As illustrated in FIGS. 5A and 5B, the clutch device 40 includes an inner ring 41 as a second member, an outer ring 42 as a first member, and a plurality of sprags 43. The inner ring 41 may function as the first member, and the outer ring 42 may function as the second member. The inner ring 41 and the outer ring 42 are cylindrical members. The inner ring 41 is disposed inside the outer ring 42. One of the inner ring 41 and the outer ring 42 is connected to the first carrier 23, and the other is connected to the casing G. In the present embodiment, the inner ring 41 is connected to the first carrier 23 and the outer ring 42 is connected to the casing G.

  The sprag 43 is a friction engagement member that engages the inner ring 41 and the outer ring 42 by friction. The sprag 43 is a columnar member, and the bottom surface has a bowl shape with a narrowed center. A circle C shown in FIG. 6 is a circle circumscribing a figure defined by the bottom surface of the sprag 43. Of the side surfaces of the sprag 43, the inner ring contact surface 61, which is a surface where the sprag 43 contacts the inner ring 41, is a curved surface having a curvature larger than the curvature of the side surface of the cylinder having the circle C as the bottom surface. Of the side surfaces of the sprag 43, the outer ring contact surface 62, which is the surface where the sprag 43 contacts the outer ring 42, is also a curved surface having a curvature larger than the curvature of the side surface of the cylinder having the circle C as the bottom surface. However, the curvature of the inner ring contact surface 61 and the curvature of the outer ring contact surface 62 may be different. The plurality of sprags 43 are arranged at equal intervals along the circumferential direction of the inner ring 41 and the outer ring 42 between the outer peripheral part of the inner ring 41 and the inner peripheral part of the outer ring 42.

  The length of the sprag 43 in the circumferential direction of the inner ring 41 and the outer ring 42 is smaller than the diameter of the circle C. Accordingly, the sprag 43 is shorter in length in the circumferential direction than the cylinder having the circle C as the bottom surface when it is disposed between the outer peripheral portion of the inner ring 41 and the inner peripheral portion of the outer ring 42. As a result, a larger number of sprags 43 can be disposed between the outer peripheral portion of the inner ring 41 and the inner peripheral portion of the outer ring 42 as compared with a cylinder having a circle C as a bottom surface.

  The main factor that determines the torque capacity of the sprag type one-way clutch device, cam clutch device, and roller clutch device is the pressure (contact) when the friction engagement members such as the sprag, cam, and roller come into contact with the inner ring and the outer ring. Pressure). When this contact pressure exceeds a certain threshold value determined by the materials of the inner ring, the outer ring, and the friction engagement member, each clutch device cannot hold the applied torque. As the number of friction engagement members constituting the clutch device increases, the torque acting on the clutch device is distributed to more friction engagement members, and the pressure when the friction engagement members come into contact with the inner ring and the outer ring becomes smaller. Therefore, the torque capacity of the clutch device increases as the number of friction engagement members increases.

  Since the sprag 43 is used as the friction engagement member in the clutch device 40, a larger number of sprags 43 than the number of cams having a bottom surface similar to the circle C can be arranged in the clutch device 40. As a result, the torque capacity of the clutch device 40 can be made larger than the torque capacity of the cam clutch device having the same mounting dimensions as the clutch device 40. Since the torque capacity of the clutch device 40 can be increased, the maximum value of the first distributed rotational force T5 output to the wheel H can be increased.

  As shown in FIG. 6, the clutch device 40 includes a ribbon spring 58 (elastic member), an outer cage 59 (first cage), and an inner cage 60 (second cage). The ribbon spring 58 is an elastic member that brings the sprags 43 into contact with the inner ring 41 and the outer ring 42, and is configured by, for example, pressing a thin stainless plate. The ribbon spring 58 has a shape in which a ladder-like member is a ring, and can be expanded and contracted in the circumferential direction. Since the sprag 43 is brought into contact with the inner ring 41 and the outer ring 42 even in the non-engaged state by the ribbon spring 58, the backlash when shifting from the non-engaged state to the engaged state is reduced, and the inner ring 41 or the outer ring is reduced. When a rotational force is applied to 42, the sprag 43 can quickly mesh with the inner ring 41 and the outer ring 42. Therefore, the clutch device 40 can reduce the time required for switching from the non-engaged state to the engaged state. In the non-engagement state, no force is transmitted between the inner ring 41 and the outer ring 42. In the engaged state, force is transmitted between the inner ring 41 and the outer ring 42.

  The outer cage 59 and the inner cage 60 are both cylindrical. On the side surface of the outer cage 59, a plurality of openings 63a (first openings) rectangular in the circumferential direction are formed at equal intervals. The outer cage 59 is disposed inside the outer ring 42. The outer diameter of the inner cage 60 is smaller than the inner diameter of the outer cage 59, and the inner cage 60 is disposed inside the outer cage 59. On the side surface of the inner cage 60, the same number of openings 63b (second openings) as the openings 63a formed in the outer cage 59 are formed at equal intervals in the circumferential direction in the circumferential direction. ing. The inner cage 60 is arranged with respect to the outer cage 59 so that the opening 63a and the opening 63b face each other. The sprag 43 is inserted through the opening 63a of the outer cage 59 and the opening 63b of the inner cage 60 opposite to the opening 63a, so that the outer cage 59 and the inner cage 60 are connected to the plurality of sprags 43. Hold.

  The plurality of openings 63a are formed at equal intervals in the circumferential direction of the outer cage 59 and the plurality of openings 63b are formed at equal intervals in the circumferential direction of the inner cage 60. In the circumferential direction of 59, that is, in the circumferential direction of the inner cage 60, they are arranged at equal intervals. The outer ring contact surface 62 protrudes outward in the radial direction of the outer cage 59 from an opening 63 a formed in the outer cage 59. The inner ring contact surface 61 protrudes inward in the radial direction of the inner cage 60 from an opening 63 b formed in the inner cage 60.

  Thus, the outer retainer 59 and the inner retainer 60 hold the plurality of sprags 43, so that the plurality of sprags 43 are arranged at equal intervals in the circumferential direction, and the movement of the plurality of sprags 43 is synchronized. To do. As a result, the total torque acting on the clutch device 40 is equally divided and acts on each sprag 43. Therefore, the torque capacity of the clutch device 40 can be increased as compared with a clutch device that does not include the outer cage 59 and the inner cage 60.

  The clutch device 40 is a one-way clutch device. The one-way clutch device transmits only the rotational force in the first direction, and does not transmit the rotational force in the second direction that is opposite to the first direction. That is, the one-way clutch device is engaged when the first carrier 23 shown in FIGS. 1 and 3 tries to rotate in the first direction, and is not engaged when the first carrier 23 tries to rotate in the second direction. The engaged state is established. In the clutch device 40, when the rotational force in the first direction (the arrow direction in FIGS. 5-2 and 6) acts on the inner ring 41, the sprag 43 meshes with the inner ring 41 and the outer ring 42. Thereby, a rotational force is transmitted between the inner ring 41 and the outer ring 42, and the first carrier 23 receives a reaction force from the casing G. Therefore, the clutch device 40 can regulate the rotation of the first carrier 23. Further, in the clutch device 40, when the rotational force in the second direction acts on the inner ring 41, the sprag 43 does not mesh with the inner ring 41 and the outer ring 42. Thereby, no rotational force is transmitted between the inner ring 41 and the outer ring 42, and the first carrier 23 does not receive a reaction force from the casing G. Therefore, the clutch device 40 does not restrict the rotation of the first carrier 23. In this manner, the clutch device 40 realizes a function as a one-way clutch device.

  In the case of this embodiment, the clutch device 40 is in the first speed change state, that is, the state in which the second motor 12 is not operated, and the first motor 11 outputs a rotational force so as to advance the electric vehicle. When the inner ring 41 rotates in the direction in which the first carrier 23 shown in FIG. 1 rotates (spins), the engaged state is established. That is, the first direction described above is a direction in which the first motor 11 outputs a rotational force so as to advance the electric vehicle and the inner ring 41 as the second member rotates when the second motor is not operating. It is. When the second motor 12 operates in this state, the rotation direction of the second carrier 33 is reversed as described later. As a result, the clutch device 40 is in the disengaged state when in the second speed change state, that is, when the second motor 12 operates and the first motor 11 outputs a rotational force to advance the electric vehicle. Become. As described above, the clutch device 40 can follow the engagement state and the disengagement state depending on whether or not the second motor 12 is operated.

  Since the clutch device 40 is a one-way clutch device, a clutch of a type in which two rotating members are engaged by moving a piston in a cylinder with a working fluid, or two rotating members are engaged by an electromagnetic actuator. Compared to the device, a mechanism for moving the piston is not required, and no electric power is required for operating the electromagnetic actuator. The clutch device 40 can switch between the engaged state and the non-engaged state by switching the direction of the rotational force acting on the inner ring 41 or the outer ring 42 (in this embodiment, the inner ring 41), thereby reducing the number of parts. In addition, the size of itself (clutch device 40) can be reduced.

  Next, the second shift state will be described. FIG. 3 is an explanatory diagram illustrating a path through which the rotational force is transmitted when the electric vehicle drive device of the first embodiment is in the second speed change state. In the second speed change state, the first motor 11 operates. The rotational force output by the first motor 11 during the second speed change state is defined as a first rotational force T7. In the second speed change state, the second motor 12 operates. The rotational force output by the second motor 12 during the second speed change state is defined as a second rotational force T8. The clutch device 40 is in a non-engaged state. That is, in the second speed change state, the first pinion gear 22 can rotate with respect to the casing G. Thus, in the second speed change state, the circulation of the rotational force between the first planetary gear mechanism 20 and the second planetary gear mechanism 30 is interrupted. In the second speed change state, the first carrier 23 can freely revolve (rotate), so that the first sun gear 21 and the first ring gear 24 can relatively freely rotate (spin). The combined rotational force T9 shown in FIG. 3 indicates the torque transmitted to the wheel bearing 50, and its unit is Nm.

  In the second speed change state, the ratio between the first rotational force T7 and the second rotational force T8 is determined by the ratio between the number of teeth Z1 of the second sun gear 31 and the number of teeth Z4 of the second ring gear 34. The first rotational force T7 merges with the second rotational force T8 at the second carrier 33. As a result, the combined rotational force T9 is transmitted to the second ring gear 34. The first rotational force T7, the second rotational force T8, and the combined rotational force T9 satisfy the following formula (5).

  Here, since the first sun gear 21 and the first ring gear 24 rotate (rotate) in opposite directions, the second sun gear 31 and the second carrier 33 also rotate (rotate) in opposite directions. When the angular velocity of the second sun gear 31 is constant, the angular velocity of the second ring gear 34 decreases as the angular velocity of the second carrier 33 increases. Further, the angular velocity of the second ring gear 34 increases as the angular velocity of the second carrier 33 decreases. As described above, the angular velocity of the second ring gear 34 continuously changes depending on the angular velocity of the second sun gear 31 and the angular velocity of the second carrier 33. That is, the electric vehicle drive device 10 can continuously change the gear ratio by changing the angular velocity of the second rotational force T8 output from the second motor 12.

  Further, when the electric vehicle drive device 10 tries to keep the angular velocity of the second ring gear 34 constant, the electric vehicle driving device 10 outputs the angular velocity of the first rotational force T7 output by the first motor 11 and the second velocity output by the second motor 12. There are a plurality of combinations with the angular velocity of the rotational force T8. That is, even if the angular velocity of the first rotational force T7 output from the first motor 11 changes due to the change in the angular velocity of the second rotational force T8 output from the second motor 12, the angular velocity of the second ring gear 34 is changed. Can be kept constant. Thereby, the electric vehicle drive device 10 can reduce the amount of change in the angular velocity of the second ring gear 34 when switching from the first shift state to the second shift state. As a result, the electric vehicle drive device 10 can reduce the shift shock.

  Next, the second rotational force T8 output from the second motor 12 will be described. The second motor 12 needs to output a rotational force equal to or greater than the second rotational force T8 that satisfies the following equation (6). In the following formula (6), 1- (Z4 / Z1) represents a rotational force ratio between the second sun gear 31 and the second ring gear 34.

  Therefore, in order to adjust the rotational force and angular velocity of the second ring gear 34 when the first motor 11 rotates arbitrarily, the first rotational force TA, the second rotational force TB, the number of teeth Z1, the teeth The number Z4 may satisfy the following formula (7). The first rotational force TA is a rotational force at an arbitrary angular velocity of the first motor 11, and the second rotational force TB is a rotational force at an arbitrary angular velocity of the second motor 12.

  FIG. 4 is a graph illustrating an example of angular velocity-rotational force characteristics of the first motor and the second motor according to the first embodiment. The angular velocity of the output shaft of the motor and the maximum rotational force that can be output at the angular velocity are related to each other. This relationship is called the angular velocity-rotational force characteristic (rotation speed-torque characteristic, NT characteristic) of the motor. Therefore, the first rotational force TA, the second rotational force TB, the number of teeth Z1, and the number of teeth Z4 are within the range of the maximum angular velocity Nmax where the angular velocity of the output shaft of the first motor 11 is assumed from 0, It is necessary to satisfy the above formula (7). The angular velocity-rotational force characteristics shown in FIG. 4 indicate that the first rotational force TA, the second rotational force TB, and the number of teeth are within the range of the angular velocity of the output shaft of the first motor 11 from 0 to the maximum angular velocity Nmax. It is an example of the angular velocity-rotational force characteristic of the 1st motor 11 and the 2nd motor 12 in case Z1 and the number of teeth Z4 satisfy | fill said Formula (7).

  FIG. 7 is an explanatory diagram schematically illustrating the external appearance of the electric vehicle drive device according to the first embodiment. FIG. 8 is a cross-sectional view taken along the line AA of FIG. FIG. 9 is an explanatory view showing the electric vehicle drive device of Embodiment 1 in an exploded manner. Hereinafter, the overlapping description is omitted about the component demonstrated above, and it shows with the same code | symbol in a figure. As shown in FIG. 8, the casing G includes a first casing G1, a second casing G2, a third casing G3, and a fourth casing G4. The first casing G1, the second casing G2, and the fourth casing G4 are cylindrical members. The second casing G2 is provided closer to the wheel H than the first casing G1. The first casing G1 and the second casing G2 are fastened with, for example, four bolts.

  The third casing G3 is provided at the opening end opposite to the second casing G2 of the two opening ends of the first casing G1, that is, the opening end of the first casing G1 on the vehicle body side of the electric vehicle. The first casing G1 and the third casing G3 are fastened with, for example, four bolts. Accordingly, the third casing G3 closes the opening of the first casing G1. The fourth casing G4 is provided inside the first casing G1. The first casing G1 and the fourth casing G4 are fastened with, for example, eight bolts.

  As shown in FIGS. 8 and 9, the first motor 11 includes a first stator core 11a, a first coil 11b, a first insulator 11c, a first rotor 11d, a first motor output shaft 11e, And a resolver 11f. The first stator core 11a is a cylindrical member. As shown in FIG. 8, the first stator core 11a is sandwiched and positioned (fixed) between the first casing G1 and the third casing G3. The first coil 11b is provided at a plurality of locations of the first stator core 11a. The first coil 11b is wound around the first stator core 11a via the first insulator 11c.

  The first rotor 11d is disposed on the radially inner side of the first stator core 11a. The first rotor 11d includes a first rotor core 11d1 and a first magnet 11d2. The first rotor core 11d1 is a cylindrical member. A plurality of first magnets 11d2 are provided on the outer periphery of the first rotor core 11d1. The first motor output shaft 11e is a rod-shaped member. The first motor output shaft 11e is connected to the first rotor core 11d1. The first resolver 11f is provided on the first rotor core 11d1. The first resolver 11f detects the rotation angle of the first rotor core 11d1.

  The second motor 12 includes a second stator core 12a, a second coil 12b, a second insulator 12c, a second rotor 12d, and a second resolver 12f. The second stator core 12a is a cylindrical member. The second stator core 12a is sandwiched and positioned (fixed) between the first casing G1 and the second casing G2. The second coil 12b is provided at a plurality of locations of the second stator core 12a. The second coil 12b is wound around the second stator core 12a via the second insulator 12c.

  The second rotor 12d is provided on the radially inner side of the second stator core 12a. The second rotor 12d is supported by the fourth casing G4 together with the clutch device 40 so as to be able to rotate around the rotation axis R. The second rotor 12d includes a second rotor core 12d1 and a second magnet 12d2. The second rotor core 12d1 is a cylindrical member. A plurality of second magnets 12d2 are provided on the outer periphery of the second rotor core 12d1. The second resolver 12f is provided on the second rotor core 12d1. The second resolver 12f detects the rotation angle of the second rotor core 12d1.

  Here, the more preferable aspect of the 1st stator core 11a and the 2nd stator core 12a is demonstrated. The in-wheel motor is required to be downsized and to be able to transmit a larger rotational force to the wheel. Such in-wheel motors tend to include permanent magnet synchronous motors. In order to reduce energy loss due to eddy currents, permanent magnet synchronous motors are formed by stacking press-formed thin electromagnetic steel plates to form a stator core and a rotor core.

  The shearing force generated in the so-called air gap between the stator core and the rotor core of the permanent magnet synchronous motor is proportional to the surface area of the portion facing the air gap. This is because the air gap density of the shearing force acting between the stator core and the rotor core is determined by the air gap magnetic flux density, and the effective magnetic flux density of the air gap depends on the residual magnetic flux density of the permanent magnet and the core material. This is because it is determined by material characteristics such as saturation magnetization (saturation magnetic flux density) of the non-oriented electrical steel sheet.

  Moreover, there is a neodymium magnet as a magnet having good characteristics that can be used as a permanent magnet for a permanent magnet synchronous motor. However, the residual magnetic flux density of the neodymium magnet is about 1.4 [T]. On the other hand, the saturation magnetization (saturation magnetic flux density) of the non-oriented electrical steel sheet as the core material is about 1.9 [T]. As described above, the shear force in the air gap of a permanent magnet synchronous motor is excluded except for motors that are specially designed so that the output shaft can rotate at high speed and motors that are specially designed to output a large rotational force. The density is almost constant regardless of the size of the motor.

  Therefore, if the cross-sectional shape of the stator core and the cross-sectional shape of the rotor core are the same, the rotational force that can be output by the motor is proportional to the dimensions of the stator core and the rotor core in the rotation axis direction. This is because, if the cross-sectional shape of the stator core and the cross-sectional shape of the rotor core are the same, the radius of the air gap is the same even if the motor size is different. In addition, the cross-sectional shape here is a cross-sectional shape in a virtual plane orthogonal to the rotation axis of the motor. In addition, the same here includes a case where the cross-sectional shape differs due to a manufacturing error or a dimensional error.

  As described above, the electric vehicle drive device 10 adjusts the dimension of the first stator core 11a in the direction of the rotation axis R and the dimension of the second stator core 12a in the direction of the rotation axis R, so that the first torque TA The second rotational force TB, the number of teeth Z1, and the number of teeth Z4 may be designed so as to satisfy the above formula (7). For example, a cross-sectional shape of the first stator core 11a cut along a virtual plane orthogonal to the rotation axis R (hereinafter referred to as a cross-sectional shape of the first stator core 11a) and a cross-section of the second stator core 12a cut along a virtual plane orthogonal to the rotation axis R When the shape (hereinafter referred to as the cross-sectional shape of the second stator core 12a) is the same, the ratio of the dimension of the first stator core 11a in the rotation axis R direction to the dimension of the second stator core 12a in the rotation axis R direction is: It is set equal to the ratio of the first rotational force TA and the second rotational force TB calculated by the above equation (7). As a result, in the electric vehicle drive device 10, the first rotational force TA, the second rotational force TB, the number of teeth Z1, and the number of teeth Z4 satisfy the above equation (7).

  In the present embodiment, in the electric vehicle drive device 10, the cross-sectional shape of the first stator core 11a and the cross-sectional shape of the second stator core 12a are the same. Thereby, the electric vehicle drive device 10 has the effect demonstrated below. In motor design, since the cross-sectional shape of the stator core is greatly related to the magnetic characteristics of the motor, changing the cross-sectional shape of the stator core increases the labor required for motor design. Therefore, the electric vehicle drive device 10 can reduce the labor required for the design by forming the cross-sectional shape of the first stator core 11a and the cross-sectional shape of the second stator core 12a the same. Further, when the cross-sectional shape of the first stator core 11a and the cross-sectional shape of the second stator core 12a are the same, the first stator core 11a and the second stator core 12a can be manufactured with the same mold. Therefore, the electric vehicle drive device 10 can reduce labor required for manufacturing. Moreover, the electric vehicle drive device 10 can reduce the cost required for manufacturing.

  Here, as described above, the electric vehicle drive device 10 is required to be downsized. Moreover, the electric vehicle drive device 10 is disposed on the lower side in the vertical direction than the shock absorber. Therefore, the electric vehicle drive device 10 is required to be lightweight. Therefore, it is not preferable to excessively increase the dimension of the second stator core 12a in the direction of the rotation axis R. Furthermore, as shown in the above equation (5), the rotational force acting on the second ring gear 34 is determined by the ratio between the number of teeth Z1 of the second sun gear 31 and the number of teeth Z4 of the second ring gear 34. The Therefore, even if the rotational force output from the second motor 12 increases, the magnitude of the rotational force that the second ring gear 34 can transmit to the wheel H does not change. As described above, the second rotational force TB output from the second motor 12 by excessively increasing the dimension of the second stator core 12a in the direction of the rotational axis R is excessively larger than the first rotational force TA output from the first motor 11. It is not preferable to do. Below, the setting method of the preferable dimension in the rotating shaft R direction of the 2nd stator core 12a is demonstrated.

  FIG. 10 is a graph showing the appearance probability of individual differences in rotational force output by the motor. FIG. 10 shows the degree of individual difference in the dimensionless rotational force, which is the ratio between the rotational force T [Nm] output from the motor and the rotational force Td at the design value. The vertical axis in FIG. 10 represents the appearance probability density of individual differences, and the horizontal axis represents the dimensionless rotational force. The rotational force output from the motor has an error of about 18% at maximum with respect to the design value as shown in FIG. 10 due to factors such as the size of the motor and magnetic characteristics. As shown in FIG. 10, the standard deviation σ of the dimensionless rotational force is about 0.06.

  Therefore, the ratio between the first rotational force TA and the second rotational force TB is set to 82% or more of the rotational force ratio acting between the second sun gear 31 and the second carrier 33. In this embodiment, since the cross-sectional shape of the first stator core 11a and the cross-sectional shape of the second stator core 12a are the same, the dimension of the first stator core 11a in the rotation axis R direction and the dimension of the second stator core 12a in the rotation axis R direction. Is set within 3σ, that is, within 18% of the ratio of the first rotational force TA and the second rotational force TB calculated from the above equation (7). That is, the ratio between the dimension of the first stator core 11a in the direction of the rotational axis R and the dimension of the second stator core 12a in the direction of the rotational axis R is set to 82% to 118% of the rotational force ratio. As a result, the electric vehicle drive device 10 has the above-described formula in which the first rotational force TA, the second rotational force TB, the number of teeth Z1, and the number of teeth Z4 are determined by the individual differences between the first motor 11 and the second motor 12. The possibility of not satisfying (7) can be reduced.

  In the present embodiment, the case where the cross-sectional shape of the first stator core 11a and the cross-sectional shape of the second stator core 12a are the same has been described. However, the cross-sectional shape of the first rotor core 11d1 and the cross-sectional shape of the second rotor core 12d1 Is the same. Thereby, the electric vehicle drive device 10 can reduce the labor required for the design and manufacture of the first motor 11 and the second motor 12. In addition, the cost required to manufacture the first motor 11 and the second motor 12 can be reduced.

  The electric vehicle drive device 10 further includes a stat bolt 51 shown in FIGS. 7, 8, and 9, a bolt 52 shown in FIGS. 7 and 8, a shock absorber mounting portion 53, a first serration 54, 7, a second serration 56 shown in FIG. 8, and a lock nut 57. As shown in FIG. 7, the wheel bearing 50 is fastened to the second casing G2 by, for example, eight bolts 52. The waterproof panel connector 55 is provided in the first casing G1. The waterproof panel connector 55 is electrically connected to a power source to supply power to the first motor 11 and the second motor 12 provided in the casing G.

  As shown in FIG. 8, the wheel bearing 50 includes an outer ring 50a, a first inner ring 50b, and a second inner ring 50c. The outer ring 50a, the first inner ring 50b, and the second inner ring 50c are cylindrical members. The first inner ring 50b is provided on the radially inner side (rotation axis R side) than the outer ring 50a, and the second inner ring 50c is provided on the radially inner side (rotation axis R side) than the first inner ring 50b. Further, the second inner ring 50 c is provided so as to cover the second planetary gear mechanism 30. That is, the second planetary gear mechanism 30 is provided on the radially inner side (the rotation axis R side) than the second inner ring 50c.

  The first inner ring 50b and the second inner ring 50c are provided with rolling elements between the outer peripheral part of itself (the first inner ring 50b and the second inner ring 50c) and the inner peripheral part of the outer ring 50a. It can rotate (rotate) about the rotation axis R. Further, the second inner ring 50c is provided with a second ring gear 34 on the inner peripheral portion of itself (second inner ring 50c). The second ring gear 34 is formed integrally with the second inner ring 50c, for example. For example, four stat bolts 51 are provided in the flange portion of the second inner ring 50c. The stat bolt 51 is inserted into a hole provided in a wheel (not shown), and a wheel nut is screwed therein. As a result, the wheel is attached to the wheel bearing 50. The lock nut 57 applies an appropriate preload to the wheel bearing 50. Thereby, the rigidity of the wheel bearing 50 is increased.

  The shock absorber mounting portion 53 is provided in the first casing G1. Specifically, the shock absorber attachment portion 53 is provided in a portion of the first casing G1 that is on the upper side in the vertical direction when the electric vehicle drive device 10 is attached to the vehicle body of the electric vehicle. The shock absorber mounting portion 53 includes a first bolt hole 53a and a second bolt hole 53b. Bolts are inserted into the first bolt holes 53a and the second bolt holes 53b, and nuts are screwed into the bolts, whereby the electric vehicle drive device 10 is fastened to the vehicle body of the electric vehicle.

  The first serration 54 is formed on the second carrier 33. Specifically, it is formed on the outer peripheral portion of the end portion on the vehicle body side of the electric vehicle among the both end portions of the second carrier 33. The first serration 54 is fitted with the serration formed in the second rotor 12 d of the second motor 12. Thereby, the rotational force of the second rotor 12 d is coupled to the second carrier 33. In the second carrier 33, the first ring gear 24 is formed on the inner periphery of the portion where the first serration 54 is provided. The second serration 56 is formed at the end of the sun gear shaft 14 on the first motor output shaft 11e side. The second serration 56 is fitted with the first motor output shaft 11e. Thereby, the sun gear shaft 14 is connected to the first motor 11.

  With the above configuration, the electric vehicle driving apparatus 10 can drive the electric vehicle by holding the wheel and transmitting the rotational force output from the first motor 11 and the second motor 12 to the wheel. . In the present embodiment, the first motor 11, the second motor 12, the first sun gear 21, the first carrier 23, the first ring gear 24, the second sun gear 31, the second carrier 33, Although the second ring gear 34 and the wheel bearing 50 are all arranged coaxially, the electric vehicle drive device 10 does not necessarily have these components arranged coaxially. In the electric vehicle drive device 10 of the present embodiment, the second ring gear 34 is directly connected to the wheel bearing 50. However, even if the second ring gear 34 is connected to the wheel bearing 50 via a gear or a joint. Good.

(Embodiment 2)
FIG. 11 is an explanatory diagram illustrating a configuration of the electric vehicle drive device according to the second embodiment. The electric vehicle drive device 100 of the second embodiment shown in FIG. 11 is different from the electric vehicle drive device 10 of the first embodiment in the configuration of the speed change mechanism. Hereinafter, the same components as those of the electric vehicle drive device 10 according to the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. Electric vehicle drive apparatus 100 includes a speed change mechanism 103. The speed change mechanism 103 is connected to the first motor 11 to transmit (input) the rotational force output from the first motor 11. Further, the speed change mechanism 103 is connected to the second motor 12 to transmit (input) the rotational force output from the second motor 12. The speed change mechanism 103 is connected to the wheel bearing 50 and transmits (outputs) the changed rotational force to the wheel bearing 50. Wheel bearing 50 is attached to wheel H of the electric vehicle.

  The speed change mechanism 103 includes a first planetary gear mechanism 70, a second planetary gear mechanism 80, and a clutch device 90. The first planetary gear mechanism 70 is a single pinion type planetary gear mechanism. The first planetary gear mechanism 70 includes a first sun gear 71, a first pinion gear 72, a first carrier 73, and a first ring gear 74. The second planetary gear mechanism 80 is a double pinion planetary gear mechanism. The second planetary gear mechanism 80 includes a second sun gear 81, a second pinion gear 82a, a third pinion gear 82b, a second carrier 83, and a second ring gear 84. The second planetary gear mechanism 80 is disposed closer to the first motor 11 and the second motor 12 than the first planetary gear mechanism 70.

  The second sun gear 81 is supported in the casing G so as to be able to rotate (spin) about the rotation axis R. The second sun gear 81 is connected to the first motor 11. Therefore, when the first motor 11 is operated, the second sun gear 81 is transmitted with the first rotational force TA. Thereby, the second sun gear 81 rotates around the rotation axis R when the first motor 11 is operated. The second pinion gear 82 a meshes with the second sun gear 81. The third pinion gear 82b meshes with the second pinion gear 82a. The second carrier 83 holds the second pinion gear 82a so that the second pinion gear 82a can rotate (rotate) about the second pinion rotation axis Rp2. The second carrier 83 holds the third pinion gear 82b so that the third pinion gear 82b can rotate (spin) about the third pinion rotation axis Rp3. For example, the second pinion rotation axis Rp2 is parallel to the rotation axis R. The third pinion rotation axis Rp3 is parallel to the rotation axis R, for example.

  The second carrier 83 is supported in the casing G so as to be able to rotate around the rotation axis R. As a result, the second carrier 83 includes the second pinion gear 82a and the third pinion gear 82a so that the second pinion gear 82a and the third pinion gear 82b can revolve around the second sun gear 81, that is, around the rotation axis R. 82b is held. The second ring gear 84 can rotate (spin) about the rotation axis R. The second ring gear 84 meshes with the third pinion gear 82b. The second ring gear 84 is connected to the second motor 12. Therefore, when the second motor 12 is operated, the second ring gear 84 is transmitted with the second rotational force TB. Thereby, the 2nd ring gear 84 rotates (autorotates) centering on the rotating shaft R, if the 1st motor 11 act | operates.

  The first sun gear 71 is supported in the casing G so as to be able to rotate (rotate) about the rotation axis R. The first sun gear 71 is connected to the first motor 11 via the second sun gear 81. Specifically, the first sun gear 71 and the second sun gear 81 are formed integrally with the sun gear shaft 64 so as to be rotatable on the same axis (rotation axis R). The sun gear shaft 64 is connected to the first motor 11. As a result, the first sun gear 71 rotates about the rotation axis R when the second motor 12 is operated.

  The first pinion gear 72 meshes with the first sun gear 71. The first carrier 73 holds the first pinion gear 72 so that the first pinion gear 72 can rotate (rotate) about the first pinion rotation axis Rp1. The first pinion rotation axis Rp1 is, for example, parallel to the rotation axis R. The first carrier 73 is supported in the casing G so as to be able to rotate around the rotation axis R. Thus, the first carrier 73 holds the first pinion gear 72 so that the first pinion gear 72 can revolve around the first sun gear 71, that is, around the rotation axis R.

  Further, the first carrier 73 is connected to the second ring gear 84. As a result, the first carrier 73 rotates (spins) about the rotation axis R when the second ring gear 84 rotates (spins). The first ring gear 74 meshes with the first pinion gear 72. The first ring gear 74 is connected to the wheel H. Accordingly, when the first ring gear 74 rotates (spins), the wheel H rotates. The clutch device 90 can regulate the rotation of the second carrier 83. Specifically, the clutch device 90 can switch between restricting (braking) the rotation of the second carrier 83 around the rotation axis R and allowing the rotation. Similar to the clutch device 40, the clutch device 90 is a sprag type one-way clutch device in which a sprag 43 is disposed as a friction engagement member. In the clutch device 90, a second carrier 83 is connected to the inner ring. Regarding other configurations, the clutch device 90 is the same as the clutch device 40. With the clutch device 90 having such a configuration, the maximum rotational force output to the wheel H can be increased. Next, as reference, the angular velocity of each part in the first shift state will be described using a nomograph.

  FIG. 12 is a collinear diagram showing the rotational speeds of the respective parts when the electric vehicle driving apparatus of the second embodiment is in the first shift state. Hereinafter, as an example, the angular velocity of the second sun gear 81 is set to V [rad / s]. Z1, Z4, Z5, and Z7 are the same as those in the first embodiment. As shown in FIG. 12, the angular velocity of the second sun gear 81 is V [rad / s]. The rotation of the second carrier 83 is restricted by the clutch device 90. Therefore, the angular velocity of the second carrier 83 is 0 [rad / s]. Since the second planetary gear mechanism 80 is a double pinion planetary gear mechanism having two pinion gears, the rotational force transmitted from the second sun gear 81 to the second ring gear 84 is reversed by the second carrier 83. When the rotational force is transmitted from the second carrier 83 to the second ring gear 84, the rotational force is reversed and transmitted at a rate of change obtained by multiplying the rate of change when transmitted from the second sun gear 81 to the second carrier 83 by −1. That is, in FIG. 12, θ3 and θ4 are equal. Thereby, the angular velocity of the second ring gear 84 is 0.437 V [rad / s].

  The first sun gear 71 is connected to the second sun gear 81. Therefore, the angular velocity of the first sun gear 71 is V [rad / s]. The first carrier 73 is connected to the second ring gear 84. Therefore, the angular velocity of the first carrier 73 is 0.437 V [rad / s]. The angular velocity of the first ring gear 74 is 0.143 V [rad / s]. Thus, the transmission ratio of the transmission mechanism 63 is V / 0.143V = 6.99. As described above, the electric vehicle driving apparatus 100 has the same effect as the electric vehicle driving apparatus 10 according to the first embodiment based on the same principle as that of the electric vehicle driving apparatus 10 according to the first embodiment.

  However, according to the same principle as the electric vehicle drive device 10 of the first embodiment, the electric vehicle drive device 100 uses the number of teeth Z5 of the first sun gear 71 instead of satisfying the above equation (7), and the teeth of the first ring gear. When the number is Z7, the first rotational force TA, the second rotational force TB, the number of teeth Z5, and the number of teeth Z7 satisfy the following formula (8). In addition, the ratio of the first rotational force TA and the second rotational force TB of the electric vehicle drive device 100 is set to 82% or more of the rotational force ratio acting between the first sun gear 71 and the first carrier 73. .

  As described above, the in-wheel motor according to the present invention is useful for a technique for ensuring sufficient rotational force for driving an electric vehicle and reducing energy loss.

DESCRIPTION OF SYMBOLS 10, 100 Electric vehicle drive device 11 1st motor 11a 1st stator core 11b 1st coil 11c 1st insulator 11d 1st rotor 11d1 1st rotor core 11d2 1st magnet 11e 1st motor output shaft 11f 1st resolver 12 2nd motor 12a Second stator core 12b Second coil 12c Second insulator 12d Second rotor 12d1 Second rotor core 12d2 Second magnet 12f Second resolver 13, 103 Transmission mechanism 14, 64 Sun gear shaft 20, 70 First planetary gear mechanism 21, 71 First Sun gear 22, 72 First pinion gear 23, 73 First carrier 24, 74 First ring gear 30, 80 Second planetary gear mechanism 31, 81 Second sun gear 32a, 82a Second pinion gear 32b, 82b Third pinion A 33,83 second carrier 34,84 second ring gear 40, 90 clutch device 41 the inner ring (second member)
42 Outer ring (first member)
43 sprag 50 wheel bearing 50a outer ring 50b first inner ring 50c second inner ring 51 stat bolt 52 bolt 53 shock absorber mounting portion 53a first bolt hole 53b second bolt hole 54 first serration 55 waterproof panel connector 56 second serration 57 lock nut 58 Ribbon spring 59 Outer cage (first cage)
60 Inner cage (second cage)
61 inner ring contact surface 62 outer ring contact surface 63a opening (first opening)
63b opening (second opening)
G casing G1 first casing G2 second casing G3 third casing G4 fourth casing H wheel R rotation axis Rp1 first pinion rotation axis Rp2 second pinion rotation axis Rp3 third pinion rotation axis T1, T7, TA first rotation force T2, T8, TB Second rotational force T3 Circulating rotational force T4 Combined rotational force T5 First distributed rotational force T6 Second distributed rotational force T9 Combined rotational force Z1, Z4, Z5, Z7 Number of teeth

Claims (5)

A first motor;
A second motor;
A first sun gear coupled to the first motor;
A first pinion gear meshing with the first sun gear;
A first carrier that holds the first pinion gear so that the first pinion gear can rotate and the first pinion gear can revolve around the first sun gear;
The first member, the second member that can rotate with respect to the first member, and the rotational force in the first direction acting on the second member transmit the rotational force between the first member and the second member. And a plurality of sprags not transmitting rotational force between the first member and the second member when a rotational force in a second direction opposite to the first direction acts on the second member, A clutch device capable of regulating the rotation of the first carrier;
A first ring gear meshing with the first pinion gear and coupled to the second motor;
A second sun gear coupled to the first motor;
A second pinion gear meshing with the second sun gear;
A third pinion gear meshing with the second pinion gear;
The second pinion gear and the third pinion gear can rotate around the second pinion gear and the third pinion gear so that the second pinion gear and the third pinion gear can revolve around the second sun gear, respectively. A second carrier that holds the third pinion gear and is coupled to the first ring gear;
A second ring gear meshing with the third pinion gear and coupled to a wheel of the electric vehicle;
Including
The first direction is a direction in which the first motor outputs a rotational force to advance the electric vehicle and the second member rotates when the second motor is not operating. A featured in-wheel motor. A first motor;
A second motor;
A first sun gear coupled to the first motor;
A first pinion gear meshing with the first sun gear;
A first carrier that holds the first pinion gear so that the first pinion gear can rotate and the first pinion gear can revolve around the first sun gear;
A first ring gear meshing with the first pinion gear and coupled to a wheel of the electric vehicle;
A second sun gear coupled to the first motor;
A second pinion gear meshing with the second sun gear;
A third pinion gear meshing with the second pinion gear;
The second pinion gear and the third pinion gear can rotate around the second pinion gear and the third pinion gear so that the second pinion gear and the third pinion gear can revolve around the second sun gear, respectively. A second carrier holding a third pinion gear;
The first member, the second member that can rotate with respect to the first member, and the rotational force in the first direction acting on the second member transmit the rotational force between the first member and the second member. And a plurality of sprags not transmitting rotational force between the first member and the second member when a rotational force in a second direction opposite to the first direction acts on the second member, A clutch device capable of regulating the rotation of the second carrier;
A second ring gear meshing with the third pinion gear, coupled to the first carrier, and coupled to the second motor;
Including
The first direction is a direction in which the first motor outputs a rotational force to advance the electric vehicle and the second member rotates when the second motor is not operating. A featured in-wheel motor.   The in-wheel motor according to claim 1, wherein the clutch device includes an elastic member that makes the sprag contact the first member and the second member.   4. The input device according to claim 1, wherein the clutch device includes a first holder and a second holder that hold the plurality of sprags at equal intervals. 5. Wheel motor. The first cage is a cylinder having a plurality of first openings arranged at equal intervals on the side surface,
The second retainer has the same number of second openings as the first retainer arranged at equal intervals on the side surface, and has an outer diameter smaller than the inner diameter of the first retainer. A cylinder,
The second holder is disposed inside the first holder so that the first opening and the second opening are opposed to each other, and the first opening and the opposed The in-wheel motor according to claim 4, wherein the sprag is inserted through the second opening.