JP2015227691A - Continuously variable transmission - Google Patents

Abstract

To suppress divergence of a skew angle.
A first guide that guides first to third power transmission members 10, 20, 30, a plurality of planetary balls 40, and a first protrusion 41a of a support shaft 41 of the planetary balls 40 in a radial direction. A non-rotatable first guide member 50A provided with a portion 51, a non-rotatable second guide member 50B provided with a second guide portion 52 for guiding the second protrusion 41b of the support shaft 41 in the radial direction, A speed change member 50C having a speed change portion 53 whose longitudinal direction is inclined with respect to the radial direction so as to balance the force acting between the second protrusion 41b and the side wall during rolling, and a speed change member An actuator 81 that rotates the member 50C, and the transmission 53 has a first tilted longitudinal direction with respect to the radial direction so that the force acting between the second protrusion 41b and the side wall is balanced during forward rotation. 1 area and its power when fishing in reverse A second region is tilted in the longitudinal direction with respect to the radial direction Migihitsuji, to have.
[Selection] Figure 4

Description

  The present invention relates to a traction drive type continuously variable transmission that continuously changes a gear ratio between input and output.

  Conventionally, as this type of continuously variable transmission, for example, a ball planetary type disclosed in Patent Documents 1 and 2 below is known. This continuously variable transmission has three power transmission elements (two discs or two rings and a sun roller) having a common rotation center shaft, and a plurality of radial transmissions with respect to the rotation center shaft. A rolling element (planetary ball) sandwiched between the power transmission elements and a holding element (carrier) that holds each planetary ball via both ends of the support shaft so that the planetary ball can tilt and rotate. The holding element includes two disk-shaped plates whose center axis is aligned with the rotation center axis. In the continuously variable transmission of Patent Document 1, each rolling element is tilted together with each support shaft by rotating the other plate (rotating plate) around the rotation center axis with respect to one plate (fixed plate). Turn. For this reason, the fixed plate is formed with a guide portion for guiding one end portion of the support shaft in the radial direction of the plate. In addition, the rotating plate has a transmission portion whose longitudinal direction is inclined in the circumferential direction of the plate with respect to the radial direction of the plate (that is, a transmission portion corresponding to the guide portion of the fixed plate inclined in the circumferential direction of the plate). ) Is formed. The other end of the support shaft is inserted into the speed change portion, and moves along the speed change portion as the rotating plate rotates. In addition, the guide part equivalent to the fixed plate is formed in each plate of patent document 2. As shown in FIG. Since the guide portion has an opening at the end on the outer peripheral surface side of the plate, the width of the opening (the width in the circumferential direction of the plate) is set to the width of the remaining portion in order to prevent the support shaft from falling off from the opening. More spread out.

Special table 2012-506001 gazette JP 2012-122568 A

  By the way, in this type of continuously variable transmission, in order to perform a smooth tilting operation, a gap is provided between the width of the guide portion (the width in the direction perpendicular to the longitudinal direction of the guide portion) and the support shaft. Yes. For this reason, when the rotation speeds of the first power transmission element and the second power transmission element are different, a moment in a direction different from the tilting direction acts on each rolling element, and the rotation center axis ( The support shaft is displaced and skew occurs. When the rolling element is tilted by the relative rotation of the two plates, the support shaft and the speed change groove depend on the relationship between the tilt direction of the speed change groove of the rotation plate and the rotation directions of the first and second power transmission elements. The forces acting on the side walls of each other are balanced, and the skew angle can be kept stable. However, when the rotation directions of the first and second power transmission elements are reversed, the forces acting between them are not balanced, and the skew angle diverges, for example, the support shaft bites into the guide portion. The support shaft may be locked. That is, when the first and second power transmission elements are reversely rotated, there is a possibility that power transmission and subsequent change of the gear ratio cannot be performed.

  Therefore, the present invention provides a continuously variable transmission that improves the disadvantages of the conventional example and can suppress the divergence of the skew angle regardless of whether the rotation directions of the first and second power transmission elements are normal or reverse. The purpose is to do.

  In order to achieve the above object, the present invention has a first rotation center axis common to each other, and a first to a third rotation capable of relative rotation in the circumferential direction with respect to the first rotation center axis between each other. A plurality of power transmission elements and a second rotation center axis are arranged radially on the outer peripheral surface of the third power transmission element with the first rotation center axis as a center, and the first rotation positions are opposed to each other. And a rolling element sandwiched between the second power transmission elements, a support shaft of the rolling element that is concentric with the second rotation center axis and has both ends projecting from the rolling element, and inserted A non-rotatable guide member provided with a guide portion for guiding the first projecting portion of the support shaft in the radial direction with respect to the first rotation center shaft, and a transmission portion into which the second projecting portion of the support shaft is inserted. A transmission member capable of rotating in the circumferential direction, and a transmission ratio between input and output An actuator that rotates the transmission member to move the second protrusions along the transmission unit and tilt the rolling elements, and the transmission unit includes: The first and second power transmission elements are used in the forward gear ratio, and the longitudinal direction is set in the radial direction so that the force acting between the second protrusion and the side wall is balanced during the forward rotation. The first region tilted with respect to the first and second power transmission elements is used in the reverse gear ratio at the time of reverse rotation, and acts between the second protrusion and the side wall during the reverse rotation. And a second region in which the longitudinal direction is inclined with respect to the radial direction so as to balance the force to be applied.

  Here, the tilt direction of the second region with respect to the radial direction is preferably opposite to the tilt direction of the first region with respect to the radial direction.

  In the continuously variable transmission according to the present invention, the second projecting portion of the support shaft enters the second region of the transmission unit when reversing (when the first and second power transmission elements are reversely rotated). For this reason, this continuously variable transmission can suppress the divergence of the skew angle not only when moving forward (when the first and second power transmission elements are rotating forward) but also when moving backward. Therefore, in this continuously variable transmission, it is possible to avoid the support shaft from being locked during reverse movement, so that the power of the power source can be transmitted to the drive wheels when the R range during reverse movement is selected. In addition, the gear ratio can be changed during forward movement after the R range is selected.

FIG. 1 is a diagram showing an example of the configuration of a continuously variable transmission according to the present invention. FIG. 2 is a diagram illustrating the first guide member of the carrier. FIG. 3 is a diagram illustrating a second guide member and a transmission member of the carrier. FIG. 4 is a diagram for explaining the transmission member of the carrier. FIG. 5 is a diagram showing the force acting on the planetary ball during forward movement and the force generated on the support shaft along with the force. FIG. 6 is a diagram showing the force acting on the planetary ball during forward movement and the force generated on the support shaft along with the force. FIG. 7 is a diagram showing the force acting on the planetary ball at the time of retreat and the force generated on the support shaft along with the force. FIG. 8 is a diagram showing the force acting on the planetary ball at the time of retreat and the force generated on the support shaft along with the force. FIG. 9 is a diagram illustrating the force acting between the second protrusion and the side wall side of the first region of the transmission during forward rotation. FIG. 10 is a diagram illustrating the force that acts when reversed in the first region. FIG. 11 is a diagram illustrating the force acting between the second protrusion and the side wall side of the second region of the transmission during reverse rotation. FIG. 12 is a flowchart for explaining the operation at the time of shift control of the continuously variable transmission according to the present invention.

  Embodiments of a continuously variable transmission according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited to the embodiments.

[Example]
An embodiment of a continuously variable transmission according to the present invention will be described with reference to FIGS.

  The continuously variable transmission of the present embodiment is a so-called traction drive type continuously variable transmission, and a ball planetary type is exemplified.

  This continuously variable transmission includes first to third power transmission elements, rolling elements, and holding elements. The first to third power transmission elements have a common first rotation center axis R1 between them, and are capable of relative rotation in the circumferential direction with respect to the first rotation center axis R1 between them. . The rolling elements have a second rotation center axis R2, and a plurality of rolling elements are arranged radially on the outer peripheral surface of the third power transmission element with the first rotation center axis R1 as the center, and are arranged opposite to each other. It is sandwiched between the second power transmission elements. The holding element holds each rolling element so that it can tilt and rotate.

  In the following, unless otherwise specified, the direction along the first rotation center axis R1 is referred to as an axial direction, and the direction around the first rotation center axis R1 is referred to as a circumferential direction. In addition, the direction orthogonal to the first rotation center axis R1 is referred to as a radial direction.

  The tilt of the rolling element refers to the movement of the second rotation center axis R2 relative to the first rotation center axis R1 on the tilt plane including the second rotation center axis R2 and the first rotation center axis R1. It is. Specifically, the shortest distance from the second rotation center axis R2 to the contact portion between the first power transmission element and the rolling element, and the contact between the second rotation center axis R2 and the second power transmission element and the rolling element. The operation of changing the shortest distance to the part is called tilting operation. In this continuously variable transmission, each rolling element is tilted together with the support shaft at the same tilt angle, thereby changing the speed ratio γ between input and output steplessly. The support shaft is a rotation shaft concentric with the second rotation center axis R2, and supports the rolling element in a freely rotatable manner in a state where both ends protrude from the rolling element. The holding element holds the rolling element via both ends of the support shaft.

  This continuously variable transmission generates a traction force (tangential force) between the first to third power transmission elements and each rolling element, so that the first to third power transmission elements Torque (power) can be transmitted through each rolling element. The traction force is generated by pressing at least one of the first and second power transmission elements against each rolling element.

  In this continuously variable transmission, any one of the first to third power transmission elements serves as a torque input section, and another one serves as a torque output section. This continuously variable transmission is disposed, for example, on the power transmission path of the vehicle. In that case, the input part is connected to the power source side such as an engine (engine such as an internal combustion engine) or a rotating machine (electric motor or the like), and the output part is connected to the drive wheel side. Note that another transmission (for example, a stepped manual transmission or an automatic transmission) may be interposed between the continuously variable transmission and the drive wheels.

  One example of this continuously variable transmission will be described below with reference to FIG. Reference numeral 1 in FIG. 1 denotes a ball planetary continuously variable transmission in the present embodiment.

  In the continuously variable transmission 1, the first and second power transmission elements function as a ring gear or the like in the traction planetary mechanism. Further, the third power transmission element and the holding element function as a sun roller and a carrier in the traction planetary mechanism, respectively. Further, the rolling element functions as a ball-type pinion in the traction planetary mechanism. Therefore, the continuously variable transmission 1 includes first and second power transmission members 10 and 20 as first and second power transmission elements, a sun roller 30 as a third power transmission element, and a rolling element. Planetary balls 40, a carrier 50 as a holding element, and a shaft 60 as a transmission shaft concentric with the first rotation center axis R1. The shaft 60 is fixed to a fixed portion of the continuously variable transmission 1 in a housing or a vehicle body (not shown), and is a columnar or cylindrical fixed shaft configured not to rotate relative to the fixed portion. is there. In the continuously variable transmission 1, a state where the first rotation center axis R <b> 1 and the second rotation center axis R <b> 2 are parallel on the tilt plane (state in FIG. 1) is set as a reference position.

  The first and second power transmission members 10 and 20 are disk members (disks) or ring members (rings) whose central axes coincide with the first rotation central axis R1, and are arranged to face each other in the axial direction. . In this example, both are circular members. The first and second power transmission members 10 and 20 sandwich each planetary ball 40 from the outside in the radial direction of each planetary ball 40. For this reason, contact portions P1 and P2 are formed between the first and second power transmission members 10 and 20 and the planetary balls 40, which are in point contact with each other (strictly, elliptical surface contact). The The shapes of the contact portions P1 and P2 of the first and second power transmission members 10 and 20 are axial forces directed to the planetary ball 40 with respect to the first and second power transmission members 10 and 20 (described later). When an axial force is applied, the first and second power transmission members 10 and 20 are formed so as to apply a force (normal force) radially inward and obliquely to the planetary ball 40.

  The continuously variable transmission 1 is configured such that the shortest distances from the second rotation center axis R2 to the contact portions P1 and P2 have the same length in the state of the reference position. Further, the continuously variable transmission 1 is configured such that the contact angles θ between the first and second power transmission members 10 and 20 and the planetary balls 40 are the same. The contact angle θ is an angle formed by a line connecting the contact portions P1 and P2 with respect to the reference plane and the center of the planetary ball 40 (the center of rotation and the tilt, which corresponds to the center of gravity in the case of a sphere). is there. The reference plane is a plane extending in the radial direction having the center of each planetary ball 40.

  In the present embodiment, the first power transmission member 10 is used as a torque input portion from the power source side, and the second power transmission member 20 is used as a torque output portion to the drive wheel side. Therefore, an input shaft (first rotation shaft) 11 concentric with the first power transmission member 10 is connected to the first power transmission member 10, and the second power transmission member 20 is connected to the second power transmission member 20. And a concentric output shaft (second rotating shaft) 21 are coupled.

  The input shaft 11 can perform relative rotation in the circumferential direction with respect to the shaft 60 together with the first power transmission member 10. Further, the output shaft 21 can perform relative rotation in the circumferential direction with respect to the shaft 60 together with the second power transmission member 20. The input shaft 11 and the output shaft 21 can rotate relative to each other in the circumferential direction. The illustrated input shaft 11 extends in the axial direction toward the side where the power source is disposed, for example. The output shaft 21 extends in the same direction as the input shaft 11 while covering the input shaft 11 from the outside in the radial direction.

  The traction force Ft is generated according to the normal force Fn based on the axial force (axial force) and the traction coefficient μt (Ft = μt * Fn). Between the 1st power transmission member 10 and the input shaft 11, the 1st axial force generator 71 which generates the axial force used as the basis of the traction force Ft is provided. A second axial force generator 72 that generates the axial force is provided between the second power transmission member 20 and the output shaft 21. For example, when one of the first power transmission member 10 and the input shaft 11 rotates, the first axial force generator 71 generates an axial force therebetween. For example, when one of the second power transmission member 20 and the output shaft 21 rotates, the second axial force generator 72 generates an axial force therebetween. Therefore, a torque cam mechanism can be used for the first and second axial force generators 71 and 72.

  The sun roller 30 can perform relative rotation in the circumferential direction with respect to the shaft 60. The sun roller 30 is disposed on the radially inner side of the plurality of planetary balls 40. The planetary balls 40 are radially arranged at substantially equal intervals on the outer peripheral surface of the sun roller 30. The sun roller 30 has contact portions P3 and P4 that contact the planetary balls 40 at two locations with the reference plane as a boundary.

  The planetary ball 40 is a rolling member that rolls on the outer peripheral surface of the sun roller 30 around the support shaft 41. The planetary ball 40 is preferably a perfect sphere, but it may have a spherical shape at least in the rolling direction, for example, a rugby ball having an elliptical cross section. The contact portions P1 and P2 on the planetary ball 40 move according to their own tilting operation (that is, the gear ratio γ).

  The support shaft 41 is concentric with the second rotation center axis R2 and protrudes from the planetary ball 40 at both ends. The support shaft 41 is passed through the center of the planetary ball 40, and supports the planetary ball 40 through a bearing so as to be rotatable. The reference position of the support shaft 41 is the reference position shown in FIG. The support shaft 41 can swing (tilt) together with the planetary ball 40 between a reference position and a position tilted therefrom in the tilt plane. The tilt is performed with the center of the planetary ball 40 as a fulcrum in the tilt plane.

  In this continuously variable transmission 1, when the tilt angle of each planetary ball 40 and the support shaft 41 is the reference position, that is, when the second rotation center axis R2 is parallel to the first rotation center axis R1, it is 0 degrees. In addition, the first power transmission member 10 and the second power transmission member 20 rotate at the same rotational speed (same rotational speed). Therefore, at this time, the rotation ratio of the first power transmission member 10 to the second power transmission member 20 (ratio of rotation speed or rotation speed) is 1, and the speed ratio γ between input and output is 1 (γ = 1). On the other hand, when each planetary ball 40 and the support shaft 41 are tilted from the reference position, the shortest distance between the second rotation center axis R2 and the contact portion P1 changes, and the second rotation center axis R2 And the shortest distance between the contact part P2 changes. For this reason, one of the first power transmission member 10 and the second power transmission member 20 rotates at a higher speed than when it is at the reference position, and the other rotates at a lower speed. In the continuously variable transmission 1, the upper planetary ball 40 and the support shaft 41 in FIG. 1 are tilted counterclockwise from the reference position, and the lower planetary ball 40 and the support shaft 41 are moved from the reference position. By tilting in the clockwise direction on the paper, the speed ratio γ changes steplessly toward the speed increasing side (γ <1). In the continuously variable transmission 1, the upper planetary ball 40 and the support shaft 41 in FIG. 1 are tilted clockwise from the reference position, and the lower planetary ball 40 and the support shaft 41 are moved to the reference position. , The gear ratio γ changes steplessly toward the deceleration side (γ> 1).

  The carrier 50 includes a first guide member 50A, a second guide member 50B, and a speed change member 50C.

  The first guide member 50A is a guide member made of a disk member having a center axis coinciding with the first rotation center axis R1. The first guide member 50A is disposed between the input shaft 11 and each planetary ball 40 in the axial direction on the side where the first power transmission member 10 is disposed with the reference plane as a boundary. . The first guide member 50 </ b> A cannot rotate relative to the shaft 60 in the circumferential direction and cannot rotate. For this reason, the illustrated first guide member 50 </ b> A is fixed to the shaft 60.

  As shown in FIG. 2, the first guide member 50 </ b> A has a guide portion (hereinafter referred to as “first guide portion”) 51 for guiding the first protrusion 41 a of the support shaft 41 in the radial direction. Is provided. FIG. 2 is a diagram of the first guide member 50A viewed in the axial direction from the planetary ball 40 side. The first guide portion 51 is a groove or a notch in which the longitudinal direction (the movement direction of the first protrusion 41a on the first guide member 50A at the time of tilting) coincides with the radial direction, and the first protrusion 41a is inserted. That is, the first guide portion 51 is a radial groove or notch that guides the first protruding portion 41a in the radial direction. In this example, a gap is provided between the first guide portion 51 and the first protruding portion 41a in order to make the tilting operation of the support shaft 41 smooth. The gap is the difference between the width of the first guide portion 51 (groove width or notch width) orthogonal to the radial direction and the size of the first protrusion 41a in the orthogonal direction (outer diameter of the first protrusion 41a). It may be narrowed within a range in which the first protrusion 41a can be guided at the time of tilting.

  The second guide member 50B is a disk member having a center axis coinciding with the first rotation center axis R1. The second guide member 50B is disposed on the side where the second power transmission member 20 is disposed with the reference plane as a boundary. The second guide member 50B is non-rotatable and cannot rotate relative to the shaft 60 in the circumferential direction. In this example, although not shown, it is fixed to the first guide member 50A via a plurality of connecting shafts.

  As shown in FIG. 3, the second guide member 50 </ b> B is provided with a second guide portion 52 for guiding the second projecting portion 41 b of the support shaft 41 in the radial direction. FIG. 3 is a view of the second guide member 50B and the speed change member 50C as viewed in the axial direction from the planetary ball 40 side. The second guide portion 52 is provided at a position facing the first guide portion 51 in the axial direction. The second guide portion 52 is a notch in which the longitudinal direction (the moving direction of the second protruding portion 41b on the second guide member 50B at the time of tilting) coincides with the radial direction, and the second protruding portion 41b is Inserted. That is, the second guide portion 52 is a radial notch that guides the second protruding portion 41b in the radial direction. However, when the speed change member 50C is disposed between the second guide member 50B and each planetary ball 40, the second guide portion 52 may be a radial groove whose longitudinal direction coincides with the radial direction. The second guide portion 52 is provided with a gap between the second protrusion portion 41b in order to establish a skew angle α at the time of forward rotation and reverse rotation, which will be described later. The gap is the difference between the width of the second guide portion 52 (groove width or notch width) orthogonal to the radial direction and the size of the second protrusion 41b in the orthogonal direction (outer diameter of the second protrusion 41b). The size is such that the second protrusion 41b is not locked on the side wall side of the second guide part 52 until at least the second protrusion 41b is locked on the side wall side of the transmission part 53 during forward rotation or reverse rotation.

  The speed change member 50C is a disk member whose center axis coincides with the first rotation center axis R1. The transmission member 50C is arranged on the same side as the second guide member 50B with the reference plane as a boundary. In this example, the second guide member 50B is arranged between the speed change member 50C and each planetary ball 40. The speed change member 50C is capable of relative rotation in the circumferential direction with respect to the shaft 60. The actuator 81 shown in FIG. 4 is used for the relative rotation. The actuator 81 includes, for example, a power source such as an electric motor and a gear portion such as a worm gear that transmits the power to the gear portion on the outer peripheral portion of the speed change member 50C. FIG. 4 is a diagram of the speed change member 50 </ b> C viewed in the axial direction from the planetary ball 40 side.

  As shown in FIGS. 3 and 4, the speed change member 50 </ b> C is provided with a speed change portion 53 into which the second projecting portion 41 b of the support shaft 41 is inserted. The transmission unit 53 is a groove or a notch. The actuator 81 rotates the speed change member 50C when changing the speed ratio γ between input and output. Thereby, on the support shaft 41, the second protrusion 41 b moves along the transmission portion 53. At that time, the movement of the support shaft 41 is regulated by the first guide portion 51 and the second guide portion 52. For this reason, the support shaft 41 moves in the radial direction along with the rotation of the speed change member 50C, so that the support shaft 41 performs a tilting operation along the tilting plane together with the planetary ball 40.

  Here, a forward / reverse switching mechanism (not shown) is provided between the input shaft 11 and the power source. For this reason, the rotation direction of the input shaft 11 differs between when the vehicle moves forward and when the vehicle moves backward. Here, the rotation of the first and second power transmission members 10 and 20 during forward movement is defined as forward rotation, and the rotation of the first and second power transmission members 10 and 20 during backward movement is defined as reverse rotation.

  5 and 6 show the force acting on the planetary ball 40 at the time of forward movement (when the first and second power transmission members 10 and 20 are rotating forward), and the support shaft 41 (first projecting portion) along with the force. 41a and the second protrusion 41b). 7 and 8 show the force acting on the planetary ball 40 during reverse movement (when the first and second power transmission members 10 and 20 are reversed) and the force generated on the support shaft 41 due to the force. And. In each of these drawings, for convenience of explanation, only one contact portion between the sun roller 30 and the planetary ball 40 is provided.

  “Ftin” in FIGS. 5 and 7 is the traction force at the contact portion P1. “Ftout” is a traction force at the contact portion P2. In the planetary ball 40, a moment in a direction different from the tilting direction (a moment M1 during forward rotation and a moment M2 during reverse rotation) is generated by the traction forces Ftin and Ftout in the opposite directions. For this reason, the planetary ball 40 and the support shaft 41 are skewed so that the second rotation center axis R2 is tilted with respect to the first rotation center axis R1 (that is, the second rotation center axis R2 deviates from the tilt plane). Occurs. When the skew occurs, a force Fin1 directed to one side wall side of the first guide portion 51 acts on the first projecting portion 41a of the support shaft 41, and one of the transmission portions 53 of the transmission shaft 53 acts on the second projecting portion 41b of the support shaft 41. A force Fout1 directed toward the side wall acts.

  Each of these drawings shows a state in which the gear ratio γ is changed to the deceleration side. For this reason, the spin force Fspn1 in the tilting direction acts on the planetary ball 40 with the second power transmission member 20 (FIGS. 6 and 8). Further, “Vs” and “Vb” in FIGS. 5 and 7 indicate velocity vectors of the sun roller 30 and the planetary ball 40, respectively. A thrust force Fs corresponding to the velocity vectors Vs and Vb acts on the sun roller 30 from the planetary ball 40. Therefore, a spin force Fspn2 in the tilt direction acts on the planetary ball 40 with the sun roller 30 (FIGS. 6 and 8). Due to the spin forces Fspn1 and Fspn2, a force Fin2 directed radially inward of the first guide member 50A acts on the first protrusion 41a, and the radial direction of the speed change member 50C acts on the second protrusion 41b. An outward force Fout2 is applied. If the speed ratio γ is the same, the directions of the forces Fin2 and Fout2 are the same regardless of whether the first and second power transmission members 10 and 20 are rotating forward or backward.

  When the first and second power transmission members 10 and 20 are rotating forward, the transmission unit 53 is moved between the second projection 41b and the side wall of the transmission unit 53 by the forces Fout1 and Fout2 of the second projection 41b. The shape that balances the forces acting on the Further, the speed change portion 53 is arranged on the side wall side of the second protrusion 41b and the speed change portion 53 by the forces Fout1 and Fout2 in the second protrusion 41b even when the first and second power transmission members 10 and 20 are reversely rotated. The force acting between the two is balanced.

  Here, a speed ratio γ between the speed increasing side and the speed reducing side is used during forward travel (during forward rotation). On the other hand, at the time of reverse (during reverse rotation), the maximum speed reduction ratio is used as the speed ratio γ. Therefore, the transmission unit 53 is provided with a first region that is used in the forward gear ratio γ and a second region that is used in the reverse gear ratio γ. The second region is provided on the outer side in the radial direction than the first region.

  In the first region, the longitudinal direction (the speed change member 50C of the second protrusion 41b at the time of tilting) is balanced so that the force acting between the second protrusion 41b and the side wall of the speed changer 53 at the time of forward rotation is balanced. It is formed in a shape in which the upward movement direction) is inclined in the circumferential direction with respect to the radial direction. The center of rotation at the time of tilting is set radially outside the first rotation center axis R1. In other words, in this speed change portion 53 (groove or notch), a radial groove or notch such as the first guide portion 51 or the second guide portion 52 is first in the direction perpendicular to the radial direction. A region offset by a fixed amount is formed as the first region inside in the radial direction. The offset amount (first predetermined amount) is an amount that balances the force acting between the second protrusion 41b and the side wall of the transmission 53 during forward rotation.

  In the second region, the longitudinal direction is inclined in the circumferential direction with respect to the radial direction so that the force acting between the second projecting portion 41b and the side wall side of the transmission portion 53 during reverse rotation is balanced. Form. The tilt direction of the second region with respect to the radial direction is opposite to the tilt direction of the first region with respect to the radial direction. And the rotation center in the case of the inclination is set to radial direction outer side rather than 1st rotation center axis R1. In other words, in this speed change portion 53 (groove or notch), a radial groove or notch such as the first guide portion 51 is offset by a second predetermined amount in a direction perpendicular to the radial direction. This is formed as the second region outside in the radial direction. The offset amount (second predetermined amount) is an amount that balances the force acting between the second projecting portion 41b and the side wall of the transmission portion 53 during reverse rotation. However, the offset reference line (that is, the radial direction) in the second region is set at a position different from the offset reference line (the radial direction) in the first region in order to balance such a force (see FIG. 4).

  FIG. 9 is a diagram for explaining the force during forward rotation acting between the second projecting portion 41 b and the side wall side of the first region of the transmission portion 53. The resultant force Fg by the component forces Fg1 and Fg2 acts on the side wall side of the first region from the second protrusion 41b. Then, the resultant force -Fg by the component forces -Fg1 and -Fg2 acts on the second protrusion 41b from the side wall side of the first region. In the first region, regardless of the speed ratio γ, the forces acting between the second protrusion 41b and the side wall of the speed changer 53 are balanced during normal rotation. Therefore, during forward rotation, the first protrusion 41 a is locked on one side wall of the first guide 51, and the second protrusion 41 b is engaged on one side of the first area of the transmission 53. When stopped, the skew between the planetary ball 40 and the support shaft 41 stops at the skew angle α. Therefore, the skew is stabilized during normal rotation.

  Here, FIG. 10 shows the force when the first and second power transmission members 10, 20 are reversed in a state where the second protrusion 41 b exists in the first region of the transmission unit 53. Yes. At the time of reverse rotation, as described above, only the direction of the force Fout1 of the forces Fout1 and Fout2 at the second projecting portion 41b is opposite to that at the time of forward rotation. For this reason, when it reverses in the 1st field, force is hard to balance between the 2nd projection 41b and the side wall side of the 1st field of transmission 53, and a skew angle will diverge. When the skew angle divergence occurs, the support shaft 41 may be engaged with the first guide portion 51 or the transmission portion 53 and the support shaft 41 may be locked. That is, when reverse rotation is performed in the first region, there is a possibility that power transmission and subsequent change of the gear ratio γ cannot be performed.

  However, in the continuously variable transmission 1 of the present embodiment, the first and second power transmission members 10 and 20 are reversed when the second protrusion 41b is present in the second region of the transmission 53. . FIG. 11 is a diagram for explaining the force at the time of reverse rotation that acts between the second projecting portion 41 b and the side wall side of the second region of the transmission portion 53. The resultant force Fg by the component forces Fg1 and Fg2 acts on the side wall side of the second region from the second protrusion 41b. Then, the resultant force -Fg by the component forces -Fg1 and -Fg2 acts on the second protrusion 41b from the side wall side of the second region. That is, in the second region, the forces acting between the second protrusion 41b and the side wall of the speed changer 53 during the reverse rotation are balanced. For this reason, at the time of reverse rotation, the first protruding portion 41 a is locked on the other side wall side of the first guide portion 51, and the second protruding portion 41 b is locked on the one side wall side in the second region of the transmission portion 53. Thus, the skew between the planetary ball 40 and the support shaft 41 stops at the skew angle α. Therefore, the skew is stable even during reverse rotation.

  Here, the region used for the speed ratio γ during the reverse rotation may be used during the forward rotation.

  For example, as shown in FIG. 12, the control device (ECU) 100 of the continuously variable transmission 1 determines whether or not the reverse R range is selected as the shift range (step ST1). If the control device 100 is not in the R range, the calculation process is temporarily terminated and the process returns to step ST1. On the other hand, in the case of the R range, the control device 100 controls the actuator 81 to shift the continuously variable transmission 1 to the speed ratio γ (= maximum speed reduction ratio) when reversing (step ST2). With the speed change operation, the second protrusion 41 b enters the second region of the speed change portion 53. Therefore, in this continuously variable transmission 1, the skew is stable even during reverse rotation.

  As described above, the continuously variable transmission 1 of the present embodiment is not only at the time of forward movement (at the time of forward rotation of the first and second power transmission members 10 and 20) but also at the time of backward movement (the first and second power transmission members 10 and 20). The divergence of the skew angle α can be suppressed even when the power transmission members 10 and 20 are reversed. Therefore, in this continuously variable transmission 1, since it is possible to avoid the lock of the support shaft 41 during reverse, the power of the power source can be transmitted to the drive wheels when the R range is selected. Further, the gear ratio γ can be changed during forward movement after the R range is selected.

DESCRIPTION OF SYMBOLS 1 Continuously variable transmission R1 1st rotation center axis R2 2nd rotation center axis 10 1st power transmission member 20 2nd power transmission member 30 Sun roller 40 Planetary ball 41 Support shaft 41a 1st protrusion part 41b 2nd protrusion part 50 Carrier 50A First guide member 50B Second guide member 50C Transmission member 51 First guide portion 52 Second guide portion 53 Transmission portion 60 Shaft 81 Actuator 100 Controller

Claims (2)

First to third power transmission elements having a first rotation center axis common to each other and capable of relative rotation in the circumferential direction with respect to the first rotation center axis between each other;
The first and second powers having a second rotation center axis and arranged radially on the outer peripheral surface of the third power transmission element with the first rotation center axis as a center and facing each other. Rolling elements sandwiched between transmission elements;
A support shaft of the rolling element that is concentric with the second rotation center axis and has both ends projecting from the rolling element;
A non-rotatable guide member provided with a guide portion for guiding the first protruding portion of the inserted support shaft in a radial direction with respect to the first rotation center axis;
A speed change member capable of rotating in the circumferential direction having a speed change portion in which the second protrusion of the support shaft is inserted;
An actuator that moves each of the second protrusions along the transmission unit and tilts each of the rolling elements by rotating the transmission member when changing a transmission ratio between the input and output;
With
The speed change part is an area used in a forward gear ratio of the first and second power transmission elements, and the force acting between the second protrusion and the side wall is balanced during the forward rotation. A first region in which the longitudinal direction is inclined with respect to the radial direction, and a region used in a speed ratio at the time of reverse rotation of the first and second power transmission elements. A continuously variable transmission comprising: a second region in which a longitudinal direction is inclined with respect to a radial direction so that a force acting between the two sides is balanced.   2. The continuously variable transmission according to claim 1, wherein a tilt direction of the second region with respect to the radial direction is opposite to a tilt direction of the first region with respect to the radial direction.

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