JP2018038219A - Flywheel power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the maximum energy storage amount by decreasing a forced displacement amount of a motor rotor radially outward by a flywheel rotor.SOLUTION: A flywheel power storage device 1 includes: a motor generator 4 having a motor rotor 3 that rotates around a rotary axis R; a flywheel rotor 5 disposed radially outside the motor generator 4; and a rotary body 7 integrally rotating with the motor rotor 3. The motor rotor 3 is attached to the rotary body 7 via a connecting member 11 that connects the motor rotor 3 and the rotary body 7.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a flywheel power storage device that can store electrical energy as kinetic energy by rotating a flywheel rotor.

  For example, Patent Document 1 discloses a flywheel power storage device in which a flywheel rotor is fixed to a motor rotor of a motor generator (motor / generator). In such a flywheel power storage device, electric energy can be stored as kinetic energy by supplying electricity to the motor generator and rotating the flywheel rotor together with the motor rotor. On the other hand, by making the motor generator function as a generator, it is possible to convert the kinetic energy of the flywheel rotor into electric energy and extract it as electric power.

JP 2016-12993 A

  In the flywheel power storage device as described above, the maximum energy storage amount can be increased by increasing the rotational speeds of the flywheel rotor and the motor rotor. The extent to which the rotational speed of the flywheel rotor and motor rotor can be increased is determined by the strength and generated stress of each member. Since the flywheel rotor can be made of a hardenable steel material or the like, it is easy to increase the strength and can withstand even if the rotational speed is high. On the other hand, the motor rotor is often composed of an electromagnetic steel plate, and it is difficult to increase the strength because it is restricted by material components and processing from the viewpoint of magnetic properties. Further, when the motor rotor is fixed radially inward of the flywheel rotor as in Patent Document 1, if the flywheel rotor is displaced radially outward by centrifugal force during rotation, the motor rotor is forced to radially outwardly move. Receive. That is, in addition to the stress generated by the centrifugal force acting on the motor rotor, a stress due to the forced displacement by the flywheel rotor is also generated. For this reason, there is a possibility that the motor rotor may reach its limit even at a relatively low rotational speed, which is a limiting factor for the maximum energy storage amount.

  In view of these problems, an object of the present invention is to increase the maximum energy storage amount by decreasing the amount of forced displacement of the motor rotor radially outward by the flywheel rotor.

  The present invention relates to a flywheel comprising: a motor generator having a motor rotor that rotates around a rotation axis; and a rotating body that has a flywheel rotor disposed radially outside the motor generator and rotates integrally with the motor rotor. In the power storage device, the motor rotor is attached to the rotating body via a connecting member that connects the motor rotor and the rotating body.

  According to the present invention, the motor rotor is attached to the rotating body including the flywheel rotor via the connecting member, and is not directly fixed to the flywheel rotor. Therefore, when the flywheel rotor is displaced radially outward during rotation, at least a part of the displacement is absorbed by the deformation of the connecting member, and the amount of forced displacement acting on the motor rotor can be reduced. Accordingly, the stress generated in the motor rotor can be reduced, and the upper limit of the rotation speed that the motor rotor can withstand can be raised, so that the maximum energy storage amount can be increased.

  Moreover, in this invention, it is good for the said connection member to have at least 1 curved part or a bending part in the cross section containing the said rotating shaft.

  By providing the connecting member with a curved portion or a bent portion, the connecting member is easily deformed in the radial direction at these portions, and the amount of displacement absorbed by the connecting member can be increased. As a result, the amount of forced displacement acting on the motor rotor can be reduced more effectively.

  In the present invention, the first connection position where the connection member is connected to the rotating body is located radially outside the second connection position where the connection member is connected to the motor rotor, or The second connecting position may be the same position in the radial direction.

  No main members other than the flywheel rotor are provided outside the motor rotor in the radial direction. Therefore, the connection member (the first connection position) with the rotating body of the connection member is set to the radially outer side or the same position in the radial direction with respect to the connection position (second connection position) with the motor rotor. It can provide in a radial direction outer side, and it can avoid suitably that a connection member interferes with another member.

  In the present invention, the connecting member may connect the motor rotor and the flywheel rotor.

  In this case, an assembly error between the motor rotor and the flywheel rotor can be reduced (coaxiality can be improved), and the rotation centers of the motor rotor and the flywheel rotor more closely match. The transmission of torque between them becomes efficient.

  In the present invention, the first connection position where the connection member is connected to the rotating body may be located radially inside the second connection position where the connection member is connected to the motor rotor.

  As described above, the connection position (first connection position) of the connecting member with the rotating body is set to be radially inward of the connection position (second connection position) with the motor rotor, thereby generating a diameter generated at the first connection position during rotation. The amount of displacement outward in the direction can be reduced. As a result, the amount of forced displacement acting on the motor rotor can be effectively reduced.

It is sectional drawing of the flywheel electrical storage apparatus which concerns on this embodiment. It is a figure which shows typically the part enclosed with the dashed-dotted line in FIG. It is sectional drawing of the flywheel electrical storage apparatus which concerns on other embodiment. It is sectional drawing of the flywheel electrical storage apparatus which concerns on other embodiment.

  An example of an embodiment of a flywheel power storage device according to the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view of the flywheel power storage device 1 according to the present embodiment in a cross section including the rotation axis R. Here, the upper side of FIG. 1 is defined as the upper side of the flywheel power storage device 1, and the lower side of FIG. 1 is defined as the lower side of the flywheel power storage device 1.

  The flywheel power storage device 1 includes a motor generator 4 having a stator 2 and a motor rotor 3, and a rotating body 7 having a flywheel rotor 5 and a hub 6. The stator 2 is electrically connected to a conversion circuit 20 that can change the direction in which the current flows or can convert the current between direct current and alternating current as necessary. When electricity is supplied from the power supply device 30 to the stator 2 via the conversion circuit 20, the rotational speeds of the motor rotor 3 and the flywheel rotor 5 are increased, so that electrical energy can be stored as kinetic energy. On the other hand, for example, when electricity is supplied to the load device 40, the motor generator 4 functions as a generator by reducing the rotational speed of the motor rotor 3, and converts the kinetic energy into electrical energy. Thus, electricity can be supplied to the external load device 40.

  The stator 2 is a cylindrical member having a coil (not shown), and is fixed to a pedestal 8 disposed at the center of the flywheel power storage device 1. The motor rotor 3 is a cylindrical member disposed on the outer side in the radial direction of the stator 2, and has a configuration in which a plurality of electromagnetic steel plates are laminated in the axial direction. The motor rotor 3 is attached to the rotating body 7 via a connecting member 11 described later, and can rotate around the rotation axis R together with the rotating body 7. The base 8 is supported by the base 12, and the flywheel power storage device 1 is fixed to another structure via the base 12.

  The flywheel rotor 5 is a cylindrical member arranged on the outer side in the radial direction of the motor generator 4. The flywheel rotor 5 is heavier than the stator 2 and the motor rotor 3, and can efficiently store kinetic energy. . The hub 6 is a disk-shaped member that covers the motor generator 4 and the flywheel rotor 5. A flywheel rotor 5 is fixed to the periphery of the hub 6, and a rotating shaft (pivot shaft) 9 is fixed to the center of the hub 6. The rotation shaft 9 extends along the rotation axis R and is rotatably supported by a bearing (pivot bearing) 10 provided at the center of the base 8. Note that the flywheel rotor 5 and the hub 6 are both made of a hardenable steel material and have higher strength than the motor rotor 3.

  The connecting member 11 connects the motor rotor 3 and the flywheel rotor 5 and is a cylindrical member having an S-shaped (Z-shaped) cross-sectional shape. The connecting member 11 restrains the motor rotor 3 and the flywheel rotor 5 in the circumferential direction so that the motor rotor 3 and the flywheel rotor 5 can rotate integrally, and is deformed in the radial direction so that the motor rotor 3 And a relative displacement in the radial direction are allowed between the flywheel rotor 5 and the flywheel rotor 5. The connecting member 11 is made of a hardened steel material, like the flywheel rotor 5 and the hub 6, and has higher strength than the motor rotor 3.

  FIG. 2 is a diagram schematically illustrating a portion surrounded by a one-dot chain line in FIG. 1, and illustrates only the motor rotor 3, the flywheel rotor 5, and the connecting member 11. As shown in FIG. 2, the connecting member 11 is provided in a region extending from the upper end portion to the lower end portion of the motor rotor 3 and the flywheel rotor 5 in the axial direction, and includes a central portion 11a, a curved portion 11b, an upper surface portion 11c, a folding portion. The curved portion 11d and the lower surface portion 11e are connected to each other.

  The central part 11a is a part extending along the axial direction. The curved portion 11b is a portion that is curved radially outward from the upper end portion of the central portion 11a. The upper surface part 11c is a part further extending radially outward from the curved part 11b. The bent portion 11d is a portion that is bent radially inward from the lower end of the central portion 11a at a substantially right angle. The lower surface part 11e is a part further extending radially inward from the bent part 11d. The connecting member 11 is easily deformed in the radial direction (the shape rigidity in the radial direction is low) because the central portion 11a is long in the axial direction and the curved portion 11b and the bent portion 11d are formed. ing.

  The connecting member 11 has an upper surface portion 11 c fixed to the upper end surface of the flywheel rotor 5 by a fastening member such as a bolt, and a lower surface portion 11 e fixed to the lower end surface of the motor rotor 3 by a fastening member such as a bolt. By fixing the connecting member 11 in this manner, the connecting member 11 can be preferably formed into an S shape between the motor rotor 3 and the flywheel rotor 5 without requiring a large space in the radial direction. Further, by fixing the connecting member 11 as described above, the first connecting position P1 where the connecting member 11 is connected to the flywheel rotor 5 (rotating body 7) is the first position where the connecting member 11 is connected to the motor rotor 3. It will be located in the diameter direction outside rather than 2 connection position P2.

  When the motor rotor 3 rotates, the flywheel rotor 5 rotates integrally with the motor rotor 3. Each of the motor rotor 3 and the flywheel rotor 5 is displaced radially outward by a centrifugal force acting on itself, and as a result, stress is generated. As described above, since the flywheel rotor 5 has high strength, it can withstand a considerable speed even if the rotational speed is increased. On the other hand, it is difficult to increase the strength of the motor rotor 3 because magnetic characteristics are prioritized. Moreover, when a displacement d1 radially outward occurs in the flywheel rotor 5, if the displacement d1 of the flywheel rotor 5 acts on the motor rotor 3 as a forced displacement as it is, the stress becomes very large. For this reason, the motor rotor 3 may reach the limit even at a relatively low rotational speed, which is a limiting factor for the maximum energy storage amount of the flywheel power storage device 1.

  Therefore, in the present embodiment, the motor rotor 3 is attached to the flywheel rotor 5 via the connecting member 11. By doing so, even when a displacement d1 radially outward occurs in the flywheel rotor 5, as shown in FIG. 2, some of the displacement d1 is absorbed by the deformation of the connecting member 11 in the radial direction. The forced displacement amount d2 acting on the motor rotor 3 can be made smaller than d1. Therefore, the motor rotor 3 can be rotated at a higher rotational speed, and the maximum energy storage amount of the flywheel power storage device 1 can be increased.

(effect)
As described above, according to the flywheel power storage device 1 of the present embodiment, the motor rotor 3 is attached to the rotating body 7 including the flywheel rotor 5 via the connecting member 11 and is directly fixed to the flywheel rotor 5. It has not been. Therefore, when the flywheel rotor 5 is displaced radially outward during rotation, at least a part of the displacement d1 is absorbed by the deformation of the connecting member 11, and the forced displacement d2 acting on the motor rotor 3 is reduced. Can do. Accordingly, the stress generated in the motor rotor 3 can be reduced, and the upper limit of the rotational speed that the motor rotor 3 can withstand can be raised, so that the maximum energy storage amount can be increased.

  Further, in the present embodiment, in the cross section including the rotation axis R, the connecting member 11 has at least one curved portion 11b or a bent portion 11d. Therefore, the connecting member 11 is the bent portion 11b or the bent portion 11d. It becomes easy to deform | transform and the displacement amount absorbed by the connection member 11 can be increased. As a result, the forced displacement amount d2 acting on the motor rotor 3 can be reduced more effectively.

  Further, in the present embodiment, the first connection position P <b> 1 where the connection member 11 is connected to the rotating body 7 is located radially outside the second connection position P <b> 2 where the connection member 11 is connected to the motor rotor 3. ing. Since the main members other than the flywheel rotor 5 are generally not provided outside the motor rotor 3 in the radial direction, the first connection position P1 is set to be radially outside the second connection position P2. The member 11 can be provided on the outer side in the radial direction of the motor rotor 3, and the connection member 11 can be preferably prevented from interfering with other members.

  Further, in the present embodiment, the connecting member 11 connects the motor rotor 3 and the flywheel 5, and only the connecting member 11 exists between the motor rotor 3 and the flywheel rotor 5. For this reason, an assembly error between the motor rotor 3 and the flywheel rotor 5 can be reduced (coaxiality can be improved), and the rotation centers of the motor rotor 3 and the flywheel rotor 5 are more coincident with each other. Torque transmission between the rotor and the flywheel rotor 5 becomes efficient.

  In the present embodiment, the connecting member 11 is connected to one end portion (upper end portion) in the axial direction of the flywheel rotor 5 and the other end portion (lower end portion) in the axial direction of the motor rotor 3. Therefore, the axial dimension of the connecting member 11 can be increased. For this reason, the connecting member 11 is easily deformed in the radial direction, and the amount of displacement absorbed by the connecting member 11 can be further increased. As a result, the forced displacement amount d2 acting on the motor rotor 3 can be further effectively reduced. The end in the axial direction is a concept including not only the end surface in the axial direction but also the peripheral surface near the end surface.

  In the present embodiment, the connecting member 11 is connected to one end face (upper end face) in the axial direction of the flywheel rotor 5 and connected to the other end face (lower end face) in the axial direction of the motor rotor 3. Has been. By doing so, the cross-sectional shape of the connecting member 11 can be made S-shaped, and the shape rigidity of the connecting member 11 can be reduced, so that the amount of displacement absorbed by the connecting member 11 can be further increased. . As a result, the forced displacement amount d2 acting on the motor rotor 3 can be further effectively reduced.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and for example, as described below, modifications can be made as appropriate as long as they are described in the claims. is there.

  In the said embodiment, the connection member 11 in which the bending part 11b and the bending part 11d were formed 1 each was used. However, the specific shape of the connecting member 11 is not limited to this, and can be changed as appropriate. For example, the larger the number of the curved portions 11b and the bent portions 11d, the closer the connecting member 11 becomes to the characteristics of the spring and the easier it is to deform. Therefore, the number of the curved portions 11b and the bent portions 11d may be increased as necessary. . Moreover, the bending part 11b and the bending part 11d do not need to be provided.

  In the above embodiment, the connecting member 11 is connected to the upper end surface of the flywheel rotor 5 and to the lower end surface of the motor rotor 3. However, the connecting member 11 may be connected to the lower end surface of the flywheel rotor 5 and connected to the upper end surface of the motor rotor 3. Alternatively, the connecting member 11 may be connected to the peripheral surface (side surface) instead of the end surface of the flywheel rotor 5 or the motor rotor 3.

  In the above embodiment, the motor rotor 3 and the flywheel rotor 5 are connected by the connecting member 11. However, the connecting members 111 and 211 may connect the motor rotor 3 and the hub 6 as in the flywheel power storage devices 101 and 201 shown in FIGS. 3 and 4, for example.

  Moreover, in the said embodiment, the 1st connection position P1 where the connection member 11 is connected with the rotary body 7 is located in the radial direction outer side rather than the 2nd connection position P2 where the connection member 11 is connected with the motor rotor 3. FIG. It was supposed to be. However, for example, like the flywheel power storage device 101 shown in FIG. 3, the connection member 111 is connected to the motor rotor 3 at the first connection position P <b> 1 where the connection member 111 is connected to the rotating body 7 (hub 6). You may make it become the same position in the radial direction as the 2nd connection position P2. In this case, the radial dimension of the connecting member 111 can be made compact.

  Alternatively, for example, like the flywheel power storage device 201 shown in FIG. 4, the connecting member 211 is connected to the motor rotor 3 at the first connecting position P <b> 1 where the connecting member 211 is connected to the rotating body 7 (hub 6). It is good also as a radial inside rather than the 2nd connection position P2. If it carries out like this, the displacement amount to the radial direction outer side which arises in the 1st connection position P1 at the time of rotation can be made small, As a result, the forced displacement amount which acts on the motor rotor 3 can be reduced effectively.

  Moreover, in the said embodiment, although the connection member 11 shall be fixed to the motor rotor 3 or the rotary body 7 with fastening members, such as a volt | bolt, a fixing means is not limited to this, You may fix by welding.

  In the motor generator 4 of the above embodiment, the motor rotor 3 is disposed on the radially outer side of the stator 2, but the stator 2 may be disposed on the radially outer side of the motor rotor 3.

  Moreover, in the said embodiment, the rotary body 7 shall be comprised including the flywheel rotor 5 and the hub 6. FIG. However, it is not essential for the flywheel rotor 5 and the hub 6 to be configured separately as described above, and the rotary body 7 may be configured such that the flywheel rotor 5 and the hub 6 are integrally configured.

DESCRIPTION OF SYMBOLS 1, 101, 201 Flywheel electrical storage apparatus 2 Stator 3 Motor rotor 4 Motor generator 5 Flywheel rotor 6 Hub 7 Rotating body 11, 111, 211 Connection member 11b Bending part 11d Bending part R Rotating shaft P1 1st connection position P2 2nd Connection position

Claims (5)

A motor generator having a motor rotor that rotates about a rotation axis;
A rotary body having a flywheel rotor disposed radially outside the motor generator, and rotating integrally with the motor rotor;
A flywheel power storage device comprising:
The flywheel power storage device, wherein the motor rotor is attached to the rotating body via a connecting member that connects the motor rotor and the rotating body.   2. The flywheel power storage device according to claim 1, wherein the connecting member has at least one curved portion or a bent portion in a cross section including the rotation shaft.   The first connecting position where the connecting member is connected to the rotating body is located radially outside the second connecting position where the connecting member is connected to the motor rotor, or the second connecting position. The flywheel power storage device according to claim 1, wherein the flywheel power storage device is at the same position in a radial direction.   The flywheel power storage device according to claim 3, wherein the connecting member connects the motor rotor and the flywheel rotor.   The first connection position where the connection member is connected to the rotating body is located radially inward of the second connection position where the connection member is connected to the motor rotor. 2. The flywheel power storage device according to 2.

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