JP5522122B2 - Continuously variable transmission - Google Patents

Description

  The present invention includes a plurality of rotating elements having a common rotating shaft, and a plurality of rolling members arranged radially with respect to the rotating shaft, and each rolling element sandwiched between two of the rotating elements. The present invention relates to a continuously variable transmission that continuously changes a gear ratio between input and output by tilting a member.

  Conventionally, what is called a traction planetary gear mechanism is known as this type of continuously variable transmission. For example, the traction planetary gear mechanism includes a transmission shaft that serves as a rotation center, a plurality of rotational elements that can rotate relative to each other with the central axis of the transmission shaft as a first rotation central axis, and parallel to the first rotation central axis. With respect to the transmission shaft, a rolling member having a different second rotation center axis, a plurality of rolling members arranged radially around the first rotation center axis, a support shaft for rotating and supporting the rolling member, and a transmission shaft And a fixing element that is fixed and holds the rolling member via respective protruding portions from the rolling member on the support shaft. In this traction planetary gear mechanism, each rolling member is sandwiched between the first rotating element and the second rotating element arranged to face each other, and each rolling member is arranged on the outer peripheral surface of the third rotating element, The gear ratio is changed steplessly by tilting the rolling member. The following Patent Document 1 discloses a continuously variable transmission provided with this traction planetary gear mechanism. In the continuously variable transmission of Patent Document 1, the outer peripheral surface of a sun roller as a third rotating element is formed in a hollow shape with a central portion recessed inward in the radial direction. This sun roller and each planetary ball (rolling) Member) is configured to contact at two points. In this continuously variable transmission, the sun roller is divided into two in the axial direction so that the respective contact points can rotate relative to each other about the first rotation center axis, and the respective divided structures are interposed via the angular bearings. It is configured to be supported by a carrier as a fixing element.

  Further, a traction planetary gear mechanism of a toroidal type in which a power roller as a rolling member is sandwiched between an input disk and an output disk as first and second rotating elements is known. For example, in Patent Document 2 below, a toroidal equation that calculates a gear ratio based on the rotational speeds of the input disk and the output disk and estimates the tilt angle of the power roller based on the calculated gear ratio. A continuously variable transmission is disclosed.

US Patent Application Publication No. 2010/0267510 JP 2009-057988 A

  By the way, in the traction planetary gear mechanism, when the first and second rotating elements are used as the torque input part and the output part, between the first and second rotating elements and the rolling member sandwiched between them. Since tangential force (traction force) acts, slip occurs between them. For this reason, in the traction planetary gear mechanism, even if the gear ratio and the tilt angle are estimated as in the technique of Patent Document 2, the estimation accuracy may be reduced due to the slip.

  Accordingly, an object of the present invention is to provide a continuously variable transmission that can improve the disadvantages of the conventional example and obtain a high gear ratio estimation accuracy.

  In order to achieve the above-described object, the present invention provides a first and second rotational elements that are rotatable relative to each other and have a transmission shaft serving as a rotation center and a common first rotation center shaft disposed opposite to each other on the transmission shaft. And a second rotation center axis parallel to the first rotation center axis, and a plurality of radial rotations centered on the first rotation center axis and sandwiched between the first and second rotation elements. A rolling member having a second rotation center shaft and having both ends projecting from the rolling member, and the rolling member is tilted via the respective projecting portions of the support shaft. A holding member that is rotatably held; a first tubular portion having a first contact point with the rolling member; and a second tubular portion extending in an axial direction from the first tubular portion, A first rotating member capable of concentric relative rotation with respect to the transmission shaft, and a second contact point with the rolling member; A third rotating element including a second rotating member capable of rotating concentrically with respect to the first rotating member along the peripheral surface of the second cylindrical part, the first rotating element, and the second rotating element. A transmission that changes a transmission ratio by changing a rotation ratio between the rotation elements by a tilting operation of each of the rolling members, wherein the first rotation element is a torque input unit, and the second rotation element Is a torque output unit, the actual transmission ratio is estimated based on the rotation ratio of the first rotating member and the second rotating member in the third rotating element.

  Here, it is desirable to estimate the actual tilt angle of the rolling member based on the estimated actual gear ratio.

  Further, it is desirable to estimate a slip amount between the first and second rotating elements and the respective rolling members based on the estimated actual gear ratio and the required gear ratio.

  The first and second rotating elements have contact points with the rolling members on the radially inner side, and the first and second rotating members of the third rotating element are radially outer. It is desirable to have a contact point with each said rolling member.

  The continuously variable transmission according to the present invention estimates the actual transmission ratio based on the rotation ratio of the first rotating member and the second rotating member in the third rotating element that does not generate tangential force and slip with the rolling member. As a result, the estimation accuracy of the actual gear ratio is increased.

FIG. 1 is a partial sectional view showing the configuration of an embodiment of a continuously variable transmission according to the present invention. FIG. 2 is a perspective view showing the arrangement of the rotation angle sensor on the carrier. FIG. 3 is a diagram for explaining the guide portion of the support shaft in the carrier. FIG. 4 is a diagram for explaining the guide portion of the support shaft in the carrier. FIG. 5 is a diagram illustrating the iris plate. FIG. 6 is a diagram detailing a main part of the continuously variable transmission according to the present invention. 7 is a cross-sectional view of the first sun roller taken along line XX in FIG. FIG. 8 is a cross-sectional view of the second sun roller taken along line YY in FIG.

  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.

  First, an example of a continuously variable transmission according to the present embodiment will be described with reference to FIG. Reference numeral 1 in FIG. 1 indicates a continuously variable transmission according to this embodiment.

  The continuously variable transmission mechanism that forms the main part of the continuously variable transmission 1 includes first to third rotating elements 10, 20, 30 that are capable of relative rotation with each other and have a common first rotation center axis R 1. A plurality of rolling members 40 arranged radially about the first rotation center axis R1 and each having a second rotation center axis R2 parallel to the first rotation center axis R1 and a reference position described later. The shaft 50 serving as a transmission shaft disposed at the rotation center of the first to third rotating elements 10, 20, 30 and a so-called holding member 60 that holds each rolling member 40 in a tiltable manner. This is called a traction planetary gear mechanism. The continuously variable transmission 1 changes the speed ratio γ between input and output by inclining the second rotation center axis R2 with respect to the first rotation center axis R1 and tilting the rolling member 40. . In the following, unless otherwise specified, the direction along the first rotation center axis R1 and the second rotation center axis R2 is referred to as the axial direction, and the direction around the first rotation center axis R1 is referred to as the circumferential direction. Further, the direction orthogonal to the first rotation center axis R1 is referred to as a radial direction, and among these, the inward side is referred to as a radial inner side, and the outward side is referred to as a radial outer side.

  In this continuously variable transmission 1, the first rotating element 10 and the second rotating element 20 that are arranged to face each other hold the respective rolling members 40, and each of the rolling members 40 is used as the third rotating element. Torque can be transmitted through the rolling members 40 between the first rotating element 10, the second rotating element 20, and the third rotating element 30. For example, in the continuously variable transmission 1, one of the first to third rotating elements 10, 20, 30 is used as a torque (power) input unit, and at least one of the remaining rotating elements is used. It can be used as a torque output section. For this reason, in this continuously variable transmission 1, the ratio of the rotational speed (the number of rotations) between any rotation element serving as an input unit and any rotation element serving as an output unit is the gear ratio γ. For example, the continuously variable transmission 1 is disposed on the power transmission path of the vehicle. In that case, the input part is connected with the power source side, such as an engine and a motor, and the output part is connected with the drive wheel side. In this continuously variable transmission 1, the rotation operation of each rotation element when torque is input to the rotation element as the input unit is referred to as normal drive, and the rotation element as the output unit is in the direction opposite to that during normal drive. The rotating operation of each rotating element when torque is input is called reverse driving. For example, in the continuously variable transmission 1, according to the example of the preceding vehicle, when the torque is input from the power source side to the rotating element as the input unit and the rotating element is rotated as in acceleration or the like, Driving is performed, and reverse driving is performed when torque in the opposite direction to that during forward driving is input to the rotating rotating element serving as the output unit from the driving wheel side, such as deceleration.

  The continuously variable transmission 1 is configured to roll with the first to third rotating elements 10, 20, 30 by pressing at least one of the first and second rotating elements 10, 20 against the rolling member 40. An appropriate tangential force (traction force) is generated between the member 40 and torque can be transmitted therebetween. When two of the first to third rotating elements 10, 20, and 30 are used as the torque input part and the output part, respectively, the tangential force in the remaining rotating elements is the rotation that becomes the input part and the output part. Compared to the tangential force of the element, it is small and substantially zero. Further, the continuously variable transmission 1 tilts each rolling member 40 on a tilt plane including its second rotation center axis R2 and first rotation center axis R1, and the first rotation element 10 By changing the ratio of the rotation speed (rotation speed) between the second rotation element 20 and the second rotation element 20, the ratio of the rotation speed (rotation speed) between the input and output is changed.

  Here, in the continuously variable transmission 1, the first and second rotating elements 10 and 20 function as a ring gear as a planetary gear mechanism. Further, the third rotating element 30 functions as a sun roller of the traction planetary gear mechanism. The rolling member 40 functions as a ball-type pinion in the traction planetary gear mechanism, and the holding member 60 functions as a carrier. Hereinafter, the first and second rotating elements 10 and 20 are referred to as “first and second rotating members 10 and 20”, respectively. The third rotating element 30 is referred to as “sun roller 30”, and the rolling member 40 is referred to as “planetary ball 40”. The holding member 60 is referred to as a “carrier 60”. In the following example, the carrier 60 is a fixing element and is fixed to the shaft 50.

  The shaft 50 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. To do.

  The first and second rotating members 10 and 20 are disk members (disks) or ring members (rings) whose center axes coincide with the first rotation center axis R1, and each planetary ball is opposed in the axial direction. 40 is interposed. In this example, both are circular members.

  Each of the first and second rotating members 10 and 20 has a contact surface that comes into contact with an outer peripheral curved surface on the radially outer side of each planetary ball 40 described in detail later. Each contact surface has, for example, a concave arc surface having a curvature equivalent to the curvature of the outer peripheral curved surface of the planetary ball 40, a concave arc surface having a curvature different from the curvature of the outer peripheral curved surface, a convex arc surface, or a flat surface. doing. Here, the first and second contact surfaces are formed so that the distance from the first rotation center axis R1 to the contact point with each planetary ball 40 becomes the same length in the state of a reference position described later. The contact angles θr1 and θr2 of the rotating members 10 and 20 with respect to the planetary balls 40 are the same. The contact angles θr1 and θr2 are angles from the reference to the contact point with each planetary ball 40. Here, the radial direction is used as a reference. The respective contact surfaces are in point contact or surface contact with the outer peripheral curved surface of the planetary ball 40. Further, each contact surface is radially inward with respect to the planetary ball 40 when an axial force (pressing force) is applied from the first and second rotating members 10 and 20 toward the planetary ball 40. And an oblique force (normal force) is applied.

  In this example, the first rotating member 10 acts as a torque input portion when the continuously variable transmission 1 is positively driven, and the second rotating member 20 acts as a torque output portion when the continuously variable transmission 1 is positively driven. . Accordingly, the input shaft (first rotation shaft) 11 is connected to the first rotation member 10, and the output shaft (second rotation shaft) 21 is connected to the second rotation member 20. The input shaft 11 and the output shaft 21 can perform relative rotation in the circumferential direction with respect to the shaft 50. In the continuously variable transmission 1, the input shaft 11 may be used as an output shaft, and the output shaft 21 may be used as an input shaft.

  Here, between the input shaft 11 and the first rotating member 10, an axial force generator 71 that generates an axial force is provided. Here, a torque cam is used as the axial force generator 71. Therefore, the axial force generating portion 71 is engaged between the input shaft 11 and the first rotating member 10 by engaging the engaging member on the input shaft 11 side with the engaging member on the first rotating member 10 side. Axial force is generated and rotational torque is transmitted, and these are rotated together. Further, between the output shaft 21 and the second rotating member 20, an axial force generator 72 similar to the axial force generator 71 is disposed. The axial force generated by the axial force generators 71 and 72 is transmitted to the first rotating member 10 and the second rotating member 20, and becomes a pressing force when pressing each planetary ball 40.

  The sun roller 30 is arranged concentrically with the shaft 50 and performs relative rotation in the circumferential direction with respect to the shaft 50. A plurality of planetary balls 40 are radially arranged at substantially equal intervals on the outer peripheral surface of the sun roller 30. Accordingly, the outer peripheral surface of the sun roller 30 becomes a rolling surface when the planetary ball 40 rotates. The sun roller 30 can roll (rotate) each planetary ball 40 by its own rotation, or can rotate along with the rolling operation (rotation) of each planetary ball 40. The sun roller 30 will be described in detail later.

  The planetary ball 40 is a rolling member that rolls on the outer peripheral surface of the sun roller 30. 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 planetary ball 40 is rotatably supported by a support shaft 41 that passes through the center of the planetary ball 40. For example, the planetary ball 40 can rotate relative to the support shaft 41 with the second rotation center axis R2 as a rotation axis (that is, rotate) by a bearing disposed between the outer periphery of the support shaft 41. . Accordingly, the planetary ball 40 can roll on the outer peripheral surface of the sun roller 30 around the support shaft 41. Both ends of the support shaft 41 are projected from the planetary ball 40.

  The reference position of the support shaft 41 is a position where the second rotation center axis R2 is parallel to the first rotation center axis R1, as shown in FIG. The support shaft 41 is inclined from the reference position and from within the tilt plane including the rotation center axis (second rotation center axis R2) and the first rotation center axis R1 formed at the reference position. It can swing (tilt) with the planetary ball 40 between the positions. The tilt is performed with the center of the planetary ball 40 as a fulcrum in the tilt plane.

  The carrier 60 holds each protrusion of the support shaft 41 so as not to prevent the tilting movement of each planetary ball 40. The carrier 60 has, for example, first and second disk portions 61 and 62 having a center axis coinciding with the first rotation center axis R1. The first and second disk portions 61 and 62 are opposed to each other, and are disposed with a space therebetween so that the sun roller 30 and the planetary ball 40 can be disposed therebetween. The carrier 60 fixes the inner peripheral surface side of the first and second disk portions 61 and 62 to the outer peripheral surface side of the shaft 50, and relative rotation in the circumferential direction and relative movement in the axial direction with respect to the shaft 50 are performed. I can't do it. For example, the carrier 60 can be prohibited from relative rotation in the circumferential direction by spline fitting the inner peripheral surfaces of the first and second disk portions 61 and 62 with the outer peripheral surface of the shaft 50. . Further, in order to prevent relative movement in the axial direction, a locking member such as a snap ring may be provided on each side surface in the axial direction of the first and second disk portions 61 and 62. Further, the carrier 60 may be regulated to relative rotation and relative movement by press-fitting into the shaft 50.

  In this example, the first and second disk portions 61 and 62 are connected by a plurality of connecting shafts 65 shown in FIG. 2 so as to have a bowl shape as a whole. As a result, the carrier 60 has an open portion on the outer peripheral surface. Each planetary ball 40 is in contact with the first rotating member 10 and the second rotating member 20 through the open portion.

  The continuously variable transmission 1 is provided with guide portions 63 and 64 for guiding the support shaft 41 in the tilting direction when each planetary ball 40 tilts. In this example, the guide parts 63 and 64 are provided on the carrier 60. The guide portions 63 and 64 are radial guide grooves and guide holes for guiding the support shaft 41 protruding from the planetary ball 40 in the tilt direction, and the first and second disk portions 61 and 62 are respectively provided. Are formed for each planetary ball 40 in the opposite portions (FIGS. 3 and 4). That is, all the guide parts 63 and 64 are radially formed when viewed from the axial direction (for example, the direction of arrow A in FIG. 1).

  The guide part 63 is a guide groove having a groove width in the circumferential direction of the first disk part 61, and has a groove bottom in the axial direction thereof. Here, the guide portion 63 side of the support shaft 41 is sandwiched between two roller guides 42, 42. Therefore, the guide portion 63 is formed to have a groove width that combines not only the diameter of the support shaft 41 but also the sizes of the two roller guides 42 and 42. The roller guide 42 has a rotation axis orthogonal to the second rotation center axis R <b> 2, and rolls on the groove bottom of the guide portion 63 as the planetary ball 40 tilts.

  On the other hand, the guide portion 64 has a composite shape of a guide groove 64a and a guide hole 64b. In the guide groove 64a, the same roller guide 43 as the roller guide 42 rolls on the groove bottom when tilting. The guide groove 64a is equivalent to the guide portion 63, and is formed to have a groove width that also considers the size of the two roller guides 43, 43 sandwiching the support shaft 41. The guide hole 64b is formed by hollowing out the central portion of the groove bottom in the groove width direction of the guide groove 64a, and the support shaft 41 is inserted therein. That is, the guide portion 64 is obtained by providing the guide portion 63 with the guide hole 64b.

  In the continuously variable transmission 1, when the tilt angle θb of each planetary ball 40 is the reference position, that is, 0 degrees, the first rotating member 10 and the second rotating member 20 have the same rotational speed (the same rotational speed). ) To rotate. That is, at this time, the rotation ratio (ratio of rotation speed or rotation speed) between the first rotation member 10 and the second rotation member 20 is 1, and the speed ratio γ is 1. On the other hand, when each planetary ball 40 is tilted from the reference position, the distance from the center axis of the support shaft 41 (second rotation center axis R2) to the contact point with the first rotation member 10 changes. The distance from the central axis of the support shaft 41 to the contact point with the second rotating member 20 changes. Therefore, one of the first rotating member 10 and the second rotating member 20 rotates at a higher speed than when it is at the reference position, and the other rotates at a lower speed. For example, the second rotating member 20 has a lower rotation (deceleration) than the first rotating member 10 when the planetary ball 40 is tilted in one direction, and the first rotating member 10 is tilted in the other direction. (High speed). Therefore, in the continuously variable transmission 1, the rotation ratio (gear ratio γ) between the first rotating member 10 and the second rotating member 20 is continuously changed by changing the tilt angle θb. Can do. At the time of acceleration (γ <1) here, the upper planetary ball 40 in FIG. 1 is tilted counterclockwise on the paper surface and the lower planetary ball 40 is tilted clockwise on the paper surface. . Further, at the time of deceleration (γ> 1), the upper planetary ball 40 in FIG. 1 is tilted clockwise in the plane of the drawing, and the lower planetary ball 40 is tilted counterclockwise in the plane of the drawing.

  The continuously variable transmission 1 is provided with a transmission that changes its speed ratio γ. Since the gear ratio γ changes as the tilt angle θb of the planetary ball 40 changes, a tilting device that tilts each planetary ball 40 is used as the transmission. Here, the transmission is provided with a disk-shaped iris plate (tilting element) 80.

  The iris plate 80 is attached to the shaft 50 through a radially inner bearing, and can perform relative rotation about the first rotation center axis R <b> 1 with respect to the shaft 50. An actuator (drive unit) such as a motor (not shown) is used for the relative rotation. The driving force of this driving unit is transmitted to the outer peripheral portion of the iris plate 80 via the worm gear 81 shown in FIG.

  The iris plate 80 is disposed on the input side (contact portion side with the first rotating member 10) or the output side (contact portion side with the second rotating member 20) of each planetary ball 40 and outside the carrier 60. . In this example, it is arranged on the output side. The iris plate 80 is formed with a throttle hole (iris hole) 82 into which one protrusion of the support shaft 41 is inserted. If the radial direction of the starting point is assumed to be the reference line L, the throttle hole 82 has an arc shape that moves away from the reference line L in the circumferential direction from the radially inner side to the radially outer side. (FIG. 5). FIG. 5 is a view seen from the direction of arrow A in FIG.

  One protrusion of the support shaft 41 moves to the center side of the iris plate 80 along the aperture 82 as the iris plate 80 rotates in the clockwise direction in FIG. At this time, since the respective protrusions of the support shaft 41 are inserted into the guide grooves 63 and 64 of the carrier 60, one protrusion inserted into the throttle hole 82 moves radially inward. Further, one of the protrusions moves to the outer peripheral side of the iris plate 80 along the aperture hole 82 when the iris plate 80 rotates counterclockwise in FIG. At this time, the one protrusion moves outward in the radial direction by the action of the guide grooves 63 and 64. Thus, the support shaft 41 can move in the radial direction by the guide grooves 63 and 64 and the throttle hole 82. Therefore, the planetary ball 40 can be tilted as described above.

  By the way, when the sun roller 30 described above is concentric with the shaft 50 and has a cylindrical outer diameter that is uniform in the axial direction, the contact point with the planetary ball 40 on the outer peripheral surface is only one point. A load (normal force) from the planetary ball 40 is received only by the point. Therefore, in this case, not only the friction loss between the sun roller 30 and the planetary ball 40 at the contact point increases, but also the outer peripheral surface of the sun roller 30 or the planetary ball 40 may be damaged.

  Therefore, in this embodiment, the sun roller 30 and the planetary ball 40 are brought into contact with each other at the first and second contact points P1 and P2 (FIG. 6) dispersed in the axial direction. Here, the central portion in the axial direction of the outer peripheral surface of the sun roller 30 is recessed inward in the radial direction from both end portions in the circumferential direction, and the first and second contact points P1, P2 are formed in the recessed portions. It can be so. The shape of the hollow portion may be V-shaped, or may be an arc shape having a radius of curvature larger than the radius of the planetary ball 40. However, at the time of tilting (γ ≠ 1), there is a deviation between the peripheral speed V1 (= Rs1 * ωb) at the first contact point P1 and the peripheral speed V2 (= Rs2 * ωb) at the second contact point P2. Arise. “Rs1” is the shortest distance between the first contact point P1 and the second rotation center axis R2, and “Rs2” is the shortest distance between the second contact point P2 and the second rotation center axis R2. is there. “Ωb” is the angular velocity of the planetary ball 40. Due to the difference in peripheral speed between the first and second contact points P1 and P2, when the sun roller 30 has an integral structure, a spin loss occurs between the sun roller 30 and the planetary ball 40. Therefore, the sun roller 30 has a two-split structure of the first split structure having the first contact point P1 and the second split structure having the second contact point P2, and the first rotation center axis R1 is centered between them. It is configured so that it can be rotated relative to each other. Thereby, in this continuously variable transmission 1, although there is a peripheral speed difference between the first and second contact points P1, P2 at the time of tilting, the first rotating member (hereinafter referred to as the first divided structure) , "First sun roller") 31 and a second rotating member (hereinafter referred to as "second sun roller") 32 as a second divided structure rotate at individual speeds. For this reason, in this continuously variable transmission 1, the spin loss between the sun roller 30 and the planetary ball 40 can be reduced, and the reduction in power transmission efficiency can be suppressed. In the continuously variable transmission 1, the durability of the sun roller 30 and the planetary ball 40 is improved as the spin loss is reduced. Hereinafter, a specific configuration will be described.

  The sun roller 30 is divided into a first sun roller 31 having one outer peripheral surface in the axial direction and a second sun roller 32 having the other outer peripheral surface, with the deepest portion of the hollow portion as a boundary. One outer peripheral surface has a first contact point P1, and the other outer peripheral surface has a second contact point P2. In this sun roller 30, the shortest distance from the first rotation center axis R1 at the first contact point P1 and the second contact point P2 is made constant, and each planetary ball 40 at the first contact point P1 and the second contact point P2 is constant. In order to make the shortest distance from a plane including all the center of gravity (rotation center) (hereinafter referred to as “division reference plane”) constant, the shape of the outer peripheral surface of each of the first sun roller 31 and the second sun roller 32 is At least the portion where the first contact point P1 and the second contact point P2 exist is made to have the same shape in a symmetrical relationship with respect to the deepest part of the depression.

  The first sun roller 31 has a first cylindrical portion 31a whose outer diameter decreases toward the division reference plane, and an outer portion of the same size from the end surface on the division reference plane side of the first cylindrical portion 31a toward the axial direction. A second tubular portion 31b extending in the diameter. The outer diameter of the second cylindrical portion 31b is made smaller than the minimum outer diameter of the first cylindrical portion 31a. The first sun roller 31 has a first contact point P1 on the outer peripheral surface of the first cylindrical portion 31a. Therefore, the end surface on the division reference plane side of the first cylindrical portion 31a is provided on the division reference plane side with respect to the first contact point P1. On the other hand, in this 1st sun roller 31, the 2nd sun roller 32 concentric on the outer peripheral surface of the 2nd cylindrical part 31b is supported so that relative rotation is possible. For this reason, the second cylindrical portion 31b extends so that the end surface is closer to the carrier 60 than the second sun roller 32, so that the second sun roller 32 can be supported by the entire outer peripheral surface.

  In other words, the first sun roller 31 is an integral-type sun roller having the above-described hollow portion, and has a step having an outer diameter smaller than that of the deepest portion on one side in the axial direction with the deepest portion of the hollow portion as a boundary. A stepped portion or a groove portion is provided, and the stepped portion or the groove portion is used as a storage portion for the second sun roller 32.

  The first sun roller 31 is attached to the shaft 50 via first and second bearings so that circumferential relative rotation with respect to the shaft 50 can be performed concentrically. Here, radial bearings RB1 and RB2 are used as the first and second bearings. The radial bearings RB1 and RB2 are disposed between the inner peripheral surface of both ends in the axial direction of the first sun roller 31 and the outer peripheral surface of the shaft 50 with a space in the axial direction. The inner race is fitted to the shaft 50 while being fitted to the sun roller 31. The first sun roller 31 may be configured such that the relative movement in the axial direction with respect to the shaft 50 is prohibited by abutting the side surfaces of the inner rings of the radial bearings RB1 and RB2 against the carrier 60, for example.

  The second sun roller 32 is formed into a cylindrical shape whose outer diameter decreases toward the division reference plane, and the outer peripheral surface of the second cylindrical portion 31b of the first sun roller 31 is aligned with the central axis (first rotation central axis R1). Place on top. The second sun roller 32 has a second contact point P2 on the outer peripheral surface. Therefore, the end surface on the division reference plane side of the second sun roller 32 is provided on the division reference plane side with respect to the second contact point P2.

  Further, regarding the outer diameter of the second sun roller 32 and the outer diameter of the first cylindrical portion 31a, when the division reference plane is used as a base point, the amount of change per unit length in the axial direction from the division reference plane is constant. It is preferable to make it. This is because the positions and shapes of the first contact point P1 and the second contact point P2 are symmetric with respect to the division reference plane. For example, when the amount of change is constant, the recess is V-shaped. In this case, what is necessary is just to shape | mold the 1st cylindrical part 31a and the 2nd sun roller 32 in the cylinder shape of a truncated cone. In addition, when the amount of change is gradually increased or the like is not constant, the hollow portion is arcuate. Here, the V-shaped ones in which the angles θs1 and θs2 of the inclined surfaces of the first cylindrical portion 31a and the second sun roller 32 with respect to the first rotation center axis R1 are the same are illustrated.

  The second sun roller 32 is rotatably supported by the second cylindrical portion 31b of the first sun roller 31 via third and fourth bearings. A 3rd bearing is a bearing arrange | positioned between the internal peripheral surface of the 2nd sun roller 32, and the outer peripheral surface of the 2nd cylindrical part 31b, for example, a radial bearing, a needle roller bearing, etc. are applicable. Here, the needle roller bearing NRB is used. As a result, the second sun roller 32 can rotate in the circumferential direction relative to the first sun roller 31.

  Here, a thrust load from the planetary ball 40 in the axial direction acts on the first and second contact points P1 and P2. However, the needle roller bearing NRB cannot receive the thrust load. In the continuously variable transmission 1, if the thrust load cannot be absorbed, the first sun roller 31 and the second sun roller 32 move relative to each other in the axial direction. There is a possibility that the energy loss increases and the power transmission efficiency decreases.

  Therefore, the second sun roller 32 is attached to the first sun roller 31 via a thrust bearing TB (or an angular bearing) as a fourth bearing. Here, the end of the second sun roller 32 having the larger outer diameter (hereinafter referred to as “large-diameter side end”) is used as one race of the thrust bearing TB. For the other race, a disk member 33 facing the end portion in the axial direction is used. The disk member 33 has an inner peripheral surface fitted to the outer peripheral surface of the second cylindrical portion 31b. In this example, the locking member 34 that supports the outer side surface of the disk member 33 is fixed to the second cylindrical portion 31 b, and the thrust bearing TB receives the thrust load from the planetary ball 40, whereby the disk member 33. Is not displaced in the axial direction with respect to the second cylindrical portion 31b, and the disk member 33 is prevented from bending. Thereby, in this continuously variable transmission 1, since the thrust bearing TB absorbs the thrust load, the energy loss between the sun roller 30 and the planetary ball 40 is reduced, and the reduction in power transmission efficiency can be suppressed. .

  Furthermore, since the continuously variable transmission 1 receives the thrust load by the thrust bearing TB, it is possible to suppress the relative axial displacement between the first contact point P1 and the second contact point P2 during driving. it can. Therefore, in this continuously variable transmission 1, the change in the rotational speeds (angular velocities ωs1, ωs2) of the first sun roller 31 and the second sun roller 32 due to the displacement of the first and second contact points P1, P2; And the change of the ratio of the rotation speed (angular velocity ωs1, ωs2) can be suppressed.

  In the continuously variable transmission 1, the first sun roller 31 and the second sun roller 32 rotate at the same rotational speed (ωs1 = ωs2) when the speed ratio γ = 1, and no circumferential speed difference occurs between them. There is no difference in rotation between the races of the bearing TB. For this reason, when the gear ratio γ = 1, no loss energy is generated due to the rotational difference between the races of the thrust bearing TB, so that the power transmission efficiency is not reduced due to the rotational difference. In the continuously variable transmission 1 at this time, the needle roller bearing NRB also does not operate. Therefore, no loss energy is generated even in the needle roller bearing NRB, and the power transmission efficiency decreases due to the operation of the needle roller bearing NRB. Also does not happen. Further, in the continuously variable transmission 1 at this time, since the thrust bearing TB and the needle roller bearing NRB are not operated, the durability of the thrust bearing TB and the needle roller bearing NRB is improved.

  On the other hand, in the continuously variable transmission 1, a difference in peripheral speed is generated between the first sun roller 31 and the second sun roller 32 during tilting (when the gear ratio γ ≠ 1), but the second sun roller 32 is rotatably supported by the first sun roller 31, so that the circumferential speed difference is reduced compared to the conventional configuration in which the divided structure of the sun roller is held on the transmission shaft via a bearing, and the thrust is reduced. The rotational difference between the races of the bearing TB is also reduced. For this reason, at the time of tilting (when the gear ratio γ ≠ 1), the loss energy due to the rotational difference between the races of the thrust bearing TB can be kept low, so the power transmission efficiency is reduced due to the rotational difference. Can be suppressed. In the continuously variable transmission 1 at this time, the movement of the needle roller bearing NRB becomes slow as the peripheral speed difference decreases. Therefore, even in the needle roller bearing NRB, the energy loss is reduced and the operation of the needle roller bearing NRB is reduced. A reduction in the power transmission efficiency that is the cause can be suppressed. Moreover, since the continuously variable transmission 1 at this time has little movement of the thrust bearing TB and the needle roller bearing NRB, the durability of the thrust bearing TB and the needle roller bearing NRB is improved.

  By the way, in this continuously variable transmission 1, the electronic control unit (ECU) 100 controls the transmission at the time of shifting to the required transmission ratio γ0, so that the tilt angle (hereinafter referred to as the control command) is controlled. The planetary ball 40 is tilted up to θb0. Then, the electronic control unit 100 determines whether or not the actual tilt angle (hereinafter referred to as “actual tilt angle”) θb1 of the planetary ball 40 is equal to the required tilt angle θb0. If there is a gap between them, the transmission may be controlled to correct the actual tilt angle θb1 to coincide with the required tilt angle θb0. At the time of the comparison determination, the electronic control device 100 obtains the actual tilt angle θb1.

  Here, the tilt angle θb of the planetary ball 40 has a unique relationship with the speed ratio γ of the continuously variable transmission 1. In this example, the speed ratio γ matches the rotation ratio (ratio of rotation speed or rotation speed) between the first rotation member 10 and the second rotation member 20 as described above (Formula 1 below). ). “Ωin” is the angular velocity of the first rotating member 10, and “ωout” is the angular velocity of the second rotating member 20. Further, as shown in Equation 1, the gear ratio γ also matches the ratio of the input side distance Rin and the output side distance Rout. The input side distance Rin is the shortest distance between the input side contact point Pin and the second rotation center axis R2, and the output side distance Rout is the output side contact point Pout and the second rotation center axis R2. Is the shortest distance between. The input side contact point Pin is a contact point between the first rotating member 10 and the planetary ball 40, and the output side contact point Pout is a contact point between the second rotating member 20 and the planetary ball 40. is there.

    γ = Rout / Rin = ωout / ωin (1)

  From this, if the angular velocity ωin of the first rotating member 10 and the angular velocity ωout of the second rotating member 20 are clarified, the electronic control unit 100 determines the actual speed ratio (hereinafter referred to as “actual speed change” from the respective angular velocities ωin and ωout. The ratio γ1 is obtained, and the actual tilt angle θb1 can be calculated from the actual transmission ratio γ1. The respective angular velocities ωin and ωout may be calculated from the detected values of the respective rotation angles using the rotation angle sensors provided on the first rotating member 10 and the second rotating member 20, respectively.

  However, in this continuously variable transmission 1, a tangential force (traction force) acts between the first and second rotating members 10, 20 that are torque input portions and output portions and each planetary ball 40. This causes slipping. For example, during positive driving, torque from the power source is input to the first rotating member 10, so that the distance between the first rotating member 10 and the planetary ball 40 is greater than that between the second rotating member 20. Also the amount of slip increases. Therefore, during the positive drive, even if the actual tilt angle θb1 = 0, that is, the input side distance Rin and the output side distance Rout have the same length (Rin = Rout), the angular velocity ωin of the first rotating member 10 However, the actual speed ratio γ1 = 1 should be calculated, but a value smaller than 1 is calculated (γ1 <1). In the case of reverse driving, the angular speed ωout of the second rotating member 20 is increased, and the actual speed ratio γ1 is calculated to be larger than 1 (γ1> 1). Therefore, in this state, the estimation accuracy of the actual speed ratio γ1 and the actual tilt angle θb1 is lowered.

  Further, the electronic control unit 100 determines whether the first and second rotating members 10 and 20 are based on the deviation between the actual speed ratio γ1 and the required speed ratio γ0 or the difference between the actual tilt angle θb1 and the required tilt angle θb0. And the amount of slip between each planetary ball 40 may be estimated. However, as the estimation accuracy of the actual gear ratio γ1 and the actual tilt angle θb1 decreases, the estimation accuracy of the slip amount also decreases.

  Therefore, in the continuously variable transmission 1, the estimation accuracy of the actual speed ratio γ1 and the actual tilt angle θb1 is improved.

  Focusing on the sun roller 30 side, the first contact point P1 in the first sun roller 31 and the second contact point P2 in the second sun roller 32 are centered on the center of gravity (the aforementioned division reference plane) of the planetary ball 40. They are distributed in the axial direction and have a symmetrical positional relationship. For this reason, in the continuously variable transmission 1, the ratio of the distances Rs1 and Rs2 described above becomes the gear ratio γ (Equation 2 below). If the first sun roller 31 and the second sun roller 32 do not slip, the gear ratio γ matches the rotation ratio (ratio of rotation speed or rotation speed) between the first sun roller 31 and the second sun roller 32. . Equation 2 is an arithmetic expression based on the angular velocity ωs1 of the first sun roller 31 and the angular velocity ωs2 of the second sun roller 32.

    γ = Rs1 / Rs2 = ωs1 / ωs2 (2)

  Here, as described above, the main reason that the estimation accuracy of the actual speed ratio γ1 and the actual tilt angle θb1 is reduced is the occurrence of slip due to the tangential force generated with the torque input. However, between the first sun roller 31 and each planetary ball 40, and between the second sun roller 32 and each planetary ball 40, torque is not input to the first sun roller 31 or the second sun roller 32, so that the tangential force is substantially reduced. 0 and slip is negligible. Therefore, the speed ratio γ obtained from the rotation ratio of the first sun roller 31 and the second sun roller 32 matches the actual speed ratio γ1. Therefore, in the continuously variable transmission 1, the rotation ratio between the first sun roller 31 and the second sun roller 32 is obtained, and this rotation ratio is set as the actual transmission ratio γ1. Thus, in this continuously variable transmission 1, the estimation accuracy of the actual gear ratio γ1 is increased.

  Further, the electronic control unit 100 can accurately determine the actual tilt angle θb1 from the actual speed ratio γ1. In addition, the electronic control unit 100 is configured so that the first and second rotating members 10, 2 are based on the deviation between the actual transmission ratio γ1 and the required transmission ratio γ0 or the deviation between the actual inclination angle θb1 and the required inclination angle θb0. The amount of slip between 20 and each planetary ball 40 can also be estimated. In the continuously variable transmission 1, since a highly accurate value can be obtained for the deviation, the slip amount can be estimated with high accuracy.

  In the continuously variable transmission 1, a rotation angle sensor 91 capable of detecting the rotation angle of the first sun roller 31 is disposed in the second disk portion 62 of the carrier 60, and the rotation angle of the second sun roller 32 is detected. The rotation angle sensor 92 that can perform the above is disposed in the first disk portion 61 (FIGS. 1, 2, and 6). The signal lines 93 of the rotation angle sensors 91 and 92 are connected to the electronic control device 100. The signal line 93 branches into the rotation angle sensors 91 and 92 through the inside of the connecting shaft 65 of the carrier 60. The electronic control unit 100 obtains the angular velocity ωs1 of the first sun roller 31 and the angular velocity ωs2 of the second sun roller 32 based on the detection signals of the rotation angle sensors 91 and 92.

  As the rotation angle sensors 91 and 92, for example, so-called gap sensors, magnetic sensors, or the like whose detection values change due to changes in the distance to the measurement object are used. For this reason, the rotation angle sensor 91 is arranged with its detection portion facing the end surface of the large-diameter side end portion of the first cylindrical portion 31a of the first sun roller 31. As shown in FIG. 7, groove portions 31 c facing the detection portion of the rotation angle sensor 91 are formed at equal intervals in the circumferential direction at the large diameter side end portion of the first sun roller 31. Thereby, between the end surface of this large diameter side end part and the detection part of the rotation angle sensor 91, the part which has the groove part 31c, and the part which does not have it appear alternately at equal intervals during rotation of the 1st sun roller 31. Therefore, the change of distance appears at the interval. Further, the rotation angle sensor 92 is arranged with its detection portion facing the end surface of the large-diameter end of the second sun roller 32. As shown in FIG. 8, projecting portions 32 a that project toward the detection portion of the rotation angle sensor 91 are formed at equal intervals in the circumferential direction at the end portion on the large diameter side of the second sun roller 32. Thereby, between the end surface of this large diameter side end part and the detection part of the rotation angle sensor 92, the part which has the protrusion part 32a and the part which does not have it are rotating at equal intervals during the rotation of the 2nd sun roller 32. Since it appears, a change in distance appears at the interval.

  As described above, the continuously variable transmission 1 estimates the actual gear ratio γ1 based on the rotation ratio between the first sun roller 31 and the second sun roller 32 that does not generate tangential force and slip with the planetary ball 40. As a result, the estimation accuracy of the actual gear ratio γ1 is increased. As a result, the continuously variable transmission 1 has a high estimation accuracy of the actual tilt angle θb1 calculated based on the actual speed ratio γ1, and the deviation between the actual speed ratio γ1 and the required tilt angle θb0 is increased. The estimation accuracy of the slip amount between the first and second rotating members 10 and 20 calculated based on the planetary balls 40 is also increased.

  Furthermore, since the continuously variable transmission 1 has two first and second contact points P1 and P2 between the sun roller 30 and the planetary ball 40, the friction loss between them is reduced to transmit power. It is possible to suppress a decrease in efficiency, and it is also possible to suppress the occurrence of scratches on the outer peripheral surface of the sun roller 30 and the planetary ball 40. Further, the continuously variable transmission 1 has a structure in which the sun roller 30 is divided into two so that each divided structure (the first sun roller 31 and the second sun roller 32) has a first contact point P1 and a second contact point P2, respectively. In addition, since the first sun roller 31 and the second sun roller 32 can be rotated relative to each other, the spin loss between the sun roller 30 and the planetary ball 40 can be reduced, and the power transmission efficiency is reduced. Can be suppressed and durability can be improved. Further, the continuously variable transmission 1 supports the second sun roller 32 in a relatively rotatable manner by the first sun roller 31 via the needle roller bearing NRB and the thrust bearing TB, and the first sun roller 31 is supported by the radial bearings RB1 and RB2. Since the thrust load input to the first sun roller 31 and the second sun roller 32 from the planetary ball 40 can be absorbed by the thrust bearing TB, the reduction in power transmission efficiency is suppressed. Is possible. In the continuously variable transmission 1, the thrust bearing TB and the needle roller bearing NRB are interposed between the first sun roller 31 and the second sun roller 32 having a peripheral speed difference of 0 or small. Loss energy in the needle roller bearing NRB is reduced, and it is possible to suppress a decrease in power transmission efficiency and improve durability. As described above, according to the continuously variable transmission 1, it is possible to suppress a decrease in power transmission efficiency and improve durability.

  Here, the estimation of the actual speed ratio γ1 described above is performed by arranging the first rotating member 10 and the second rotating member 20 between each planetary ball 40 and the shaft 50, and the first sun roller 31 and the second sun roller. 32 is a continuously variable transmission in which a rotating member having the same shape as that of the planetary ball 40 is disposed on the radially outer side, that is, a continuously variable transmission in which the positional relationship between the first and second rotating members 10 and 20 and the sun roller 30 is changed. The same estimation accuracy as described above can be obtained. Also in the continuously variable transmission in this case, the first and second rotating members 10 and 20 serve as a torque input part and an output part, and the actual speed change is based on the rotation ratio of the first sun roller 31 and the second sun roller 32. The ratio γ1 is estimated.

1 continuously variable transmission 10 first rotating member (first rotating element)
20 Second rotating member (second rotating element)
30 Sun Roller (third rotating element)
31 1st sun roller 31a 1st cylindrical part 31b 2nd cylindrical part 31c Groove part 32 2nd sun roller 32a Protrusion part 33 Disk member 34 Locking member 40 Planetary ball (rolling member)
41 Support shaft 50 Shaft (transmission shaft)
60 Carrier (holding member)
80 Iris plate 91, 92 Rotation angle sensor 100 Electronic control unit P1 First contact point P2 Second contact point R1 First rotation center axis R2 Second rotation center axis

Claims (4)

A transmission shaft as a center of rotation;
First and second rotational elements capable of relative rotation having a common first rotational center axis disposed opposite to each other on the transmission shaft;
A rolling member having a second rotation center axis parallel to the first rotation center axis, and a plurality of radial members arranged radially about the first rotation center axis and sandwiched between the first and second rotation elements When,
A support shaft of the rolling member having the second rotation center axis and projecting both ends from the rolling member;
A holding member that tiltably holds the rolling member via each protrusion of the support shaft;
A first cylindrical portion having a first contact point with the rolling member and a second cylindrical portion extending in the axial direction from the first cylindrical portion, and concentric relative rotation with respect to the transmission shaft A first rotating member capable of rotating and a second contact point with the rolling member, and can be concentrically rotated with respect to the first rotating member along the peripheral surface of the second cylindrical portion. A third rotating element comprising a second rotating member;
A transmission that changes a transmission ratio by changing a rotation ratio between the first rotation element and the second rotation element by a tilting operation of each rolling member;
With
When the first rotating element is a torque input unit and the second rotating element is a torque output unit, an actual speed change is made based on a rotation ratio of the first rotating member and the second rotating member in the third rotating element. A continuously variable transmission characterized by estimating a ratio.   The continuously variable transmission according to claim 1, wherein an actual tilt angle of the rolling member is estimated based on the estimated actual gear ratio.   The slip amount between the first and second rotating elements and each of the rolling members is estimated based on the estimated actual gear ratio and the required gear ratio. Continuously variable transmission.   The first and second rotating elements have contact points with the rolling members on the radially inner side, and the first and second rotating members on the third rotating element are on the radially outer side. The continuously variable transmission according to claim 1, 2 or 3, further comprising a contact point with each rolling member.

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