JP2013167332A - Continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuously variable transmission capable of suppressing fluctuation from occurring in face pressures of a rotation transmitting part.SOLUTION: A continuously variable transmission 1 has a transmission shaft 60, a first rotation element 10 and a second rotation element 20, a plurality of rolling members 50, and a transmission 80. The plurality of rolling members 50 are arranged such that outer diameters become large from one side to the other side in a certain direction extending along a direction perpendicular to a first rotation center axis in series. The first rotation element 10 and the second rotation element 20 have fixed parts 11, 21 in which rotation center axes can not oscillate relative to the first rotation center axis R1, movable parts 12, 22 in which rotation center axes can oscillate relative to the first rotation center axis R1 and which come into contact with the rolling members 50, and transmitting parts 13, 23 capable of transmitting torque while allowing inclinations of the movable parts 12, 22 relative to the fixed parts 11, 21 respectively.

Description

  The present invention relates to a continuously variable transmission.

  As a conventional transmission of a so-called traction drive system, for example, Patent Document 1 discloses a transmission shaft serving as a rotation center, and a plurality of rotational elements capable of relative rotation with the center axis of the transmission shaft as a first rotation center axis. A continuously variable transmission (CONTINUOUSLY VARIABLE TRANSMISSIONS) is disclosed that includes a plurality of planetary balls as rolling members arranged radially about a first rotation center axis. This continuously variable transmission includes an input / output ring that sandwiches a planetary ball, a carrier that supports the planetary ball in a tiltable manner, a sun roller whose outer peripheral surface is in contact with the planetary ball, and the like as a plurality of rotating elements. The gear ratio is steplessly changed by tilting the ball. The continuously variable transmission has a configuration in which the sun roller is divided into two in the axial direction.

US Patent Application Publication No. 2011/0218072

  By the way, the continuously variable transmission described in Patent Document 1 as described above is, for example, a rotation transmission portion such as a contact portion between the planetary ball and the input / output ring due to variations in the outer diameter of the planetary ball due to manufacturing errors or the like. There is a risk of variations in the surface pressure. In other words, the continuously variable transmission described in Patent Document 1 as described above requires high manufacturing accuracy when manufacturing planetary balls in order to suppress variations in the surface pressure of the rotation transmitting portion. For example, the manufacturing cost may increase.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a continuously variable transmission that can suppress variations in the surface pressure of a rotation transmission portion.

  In order to achieve the above-mentioned object, a continuously variable transmission according to the present invention is arranged such that a transmission shaft serving as a rotation center and the transmission shaft are opposed to each other in the axial direction, with a common first rotation center axis as the rotation center. The first rotation element and the second rotation element that are relatively rotatable, and a second rotation center axis that is different from the first rotation center axis, can be rotated about the first rotation center axis, and radially about the first rotation center axis A plurality of rolling members sandwiched between the first rotating element and the second rotating element and capable of transmitting torque between the first rotating element and the second rotating element; and A plurality of rolling members having a specific direction along a direction perpendicular to the first rotation center axis. From one side to the other The first rotating element and the second rotating element are arranged so that the outer diameters are increased in order, and each of the first rotating element and the second rotating element has a fixed part whose rotation center axis cannot swing with respect to the first rotation center axis, The rotation center axis is swingable with respect to the first rotation center axis, and the movable part is in contact with the rolling member, and the fixed part and the movable part are allowed while allowing the movable part to be inclined with respect to the fixed part. And a transmission part capable of transmitting torque to and from the part.

  In the continuously variable transmission, the transmission portion includes a spline engaging portion that connects the fixed portion and the movable portion so as to be integrally rotatable and relatively movable in a direction along the first rotation center axis. And the clearance with respect to the direction orthogonal to the said 1st rotation center axis line of the said spline engaging part shall be formed larger than the displacement of the said movable part with respect to the said fixed part.

  In the continuously variable transmission, the fixed portion is formed in an annular shape or a disk shape, and a curved surface is provided on an inner peripheral surface, and the movable portion is in contact with the curved surface on the inner peripheral surface side of the fixed portion. The curved surface may be formed along a moving track of the fixed part, the movable part, and the contact point with the rotation of the fixed part and the movable part.

  The continuously variable transmission according to the present invention has an effect that it is possible to suppress variation in the surface pressure of the rotation transmission portion.

FIG. 1 is a schematic cross-sectional view of a continuously variable transmission according to an embodiment. FIG. 2 is a partial cross-sectional view of the continuously variable transmission according to the embodiment. FIG. 3 is a perspective view of the carrier of the continuously variable transmission according to the embodiment. FIG. 4 is a diagram illustrating an example of the outer diameter and surface pressure calculation of the planetary ball. FIG. 5 is a schematic cross-sectional view along the radial direction of the continuously variable transmission according to the embodiment. FIG. 6 is a schematic diagram illustrating selection of the outer diameter of the planetary ball of the continuously variable transmission according to the embodiment. FIG. 7 is a schematic cross-sectional view illustrating the outer diameter of the planetary ball of the continuously variable transmission according to the embodiment. FIG. 8 is a diagram showing an example of the surface pressure of each planetary ball 50 between the continuously variable transmission of this embodiment and the continuously variable transmission according to the comparative example.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

[Embodiment]
1 is a schematic cross-sectional view of a continuously variable transmission according to the embodiment, FIG. 2 is a partial cross-sectional view of the continuously variable transmission according to the embodiment, and FIG. 3 is a perspective view of a carrier of the continuously variable transmission according to the embodiment. 4 is a diagram illustrating an example of the outer diameter and surface pressure calculation of the planetary ball, FIG. 5 is a schematic cross-sectional view along the radial direction of the continuously variable transmission according to the embodiment, and FIG. FIG. 7 is a schematic cross-sectional view illustrating the outer diameter of the planetary ball of the continuously variable transmission according to the embodiment, and FIG. 8 is a schematic cross-sectional view illustrating the outer diameter of the planetary ball of the continuously variable transmission according to the embodiment. These are the diagrams showing an example of the surface pressure of each planetary ball 50 of the continuously variable transmission of this embodiment and the continuously variable transmission which concerns on a comparative example.

  The continuously variable transmission according to the present embodiment is mounted on a vehicle and transmits power (torque) generated by a power source such as an internal combustion engine to drive wheels of the vehicle. This continuously variable transmission is a so-called traction drive type continuously variable transmission that can transmit power between the rotating elements by a fluid such as traction oil (transmitted oil) interposed between the rotating elements in contact with each other. The continuously variable transmission uses the resistance force (traction force, shear force of the traction oil film) generated when shearing the traction oil intervening on the contact surface between one rotating element and the other rotating element to provide power (torque). To communicate. The continuously variable transmission according to the present embodiment is a so-called ball planetary continuously variable transmission (CVP: Continuously Variable Planetary).

  Specifically, as shown in FIGS. 1 and 2, the continuously variable transmission mechanism that forms the main part of the continuously variable transmission 1 of the present embodiment has a common first rotation center axis R <b> 1. A first rotating member 10 as a first rotating element capable of relative rotation, a second rotating member 20 as a second rotating element, a sun roller 30 (see FIG. 2) as a third rotating element, and a carrier as a fourth rotating element 40, 41 (see FIG. 2). Further, the continuously variable transmission 1 includes a planetary ball 50 as a plurality of rolling members each having a second rotation center axis R2 (see FIG. 2) different from the first rotation center axis R1, the first rotation member 10, A second rotation member 20 and a transmission shaft 60 that is the rotation center of the sun roller 30 are provided. Here, both the carrier 40 and the carrier 41 are disposed on the transmission shaft 60. The carrier 40 is supported so as to be relatively rotatable with respect to the transmission shaft 60 with the first rotation center axis R1 as the rotation center. On the other hand, the carrier 41 is fixed to the transmission shaft 60 so as to be integrally rotatable. The continuously variable transmission 1 changes the gear ratio between input and output by inclining the second rotation center axis R2 with respect to the first rotation center axis R1 and tilting the planetary ball 50.

  In the following description, unless otherwise specified, a direction along the first rotation center axis R1 or the second rotation center axis R2 is referred to as an axial direction, and a direction around the first rotation center axis R1 is referred to as a circumferential direction. Further, a direction orthogonal to the first rotation center axis R1 is referred to as a radial direction, and among these, a side facing inward is referred to as a radial inner side, and a side facing outward is referred to as a radial outer side.

  In the continuously variable transmission 1, torque is typically transmitted through the planetary balls 50 between the first rotating member 10, the second rotating member 20, the sun roller 30, and the carriers 40 and 41. For example, in the continuously variable transmission 1, one of the first rotating member 10, the second rotating member 20, the sun roller 30, and the carriers 40 and 41 serves as a torque (power) input unit, and at least of the remaining rotating elements. One is the torque output section. In the continuously variable transmission 1, the ratio of the rotation speed (the number of rotations) between any rotation element serving as an input unit and any rotation element serving as an output unit is a gear ratio. Here, the continuously variable transmission 1 will be described with respect to a case where the first rotating member 10 is an input unit and the second rotating member 20 is an output unit.

  In the continuously variable transmission 1, a plurality of planetary balls 50 are arranged radially about the center axis (first rotation center axis R <b> 1) of the transmission shaft 60. The planetary ball 50 can rotate (spin) about the second rotation center axis R2 as the rotation center. The planetary ball 50 is sandwiched between the first rotating member 10 and the second rotating member 20 that are disposed on the transmission shaft 60 so as to face the transmission shaft 60 in the axial direction. The planetary ball 50 is supported by the carriers 40 and 41 so as to be able to rotate. The continuously variable transmission 1 presses at least one of the first rotating member 10 and the second rotating member 20 against the planetary ball 50, whereby the first rotating member 10, the second rotating member 20, the sun roller 30 and the planetary ball 50. Appropriate frictional force (traction force) is generated between them and torque can be transmitted between them. The continuously variable transmission 1 tilts the planetary ball 50 on a tilt plane including the second rotation center axis R2 and the first rotation center axis R1, and the first rotation member 10 and the second rotation member 20 By changing the ratio of the rotational speed (rotational speed) between the input and output, the ratio of the rotational speed (rotational speed) between the input and output is changed.

  Hereinafter, each component of the continuously variable transmission 1 will be described in detail.

  The first rotating member 10 and the second rotating member 20 are a disk member (disk) or an annular member (ring), and are arranged so as to sandwich each planetary ball 50 so as to face each other in the axial direction of the first rotation center axis R1. Set up. In this example, both are circular members.

  The 1st rotation member 10 of this embodiment has the 1st fixed ring 11 as a fixed part, the 1st movable ring 12 as a movable part, and the 1st transmission part 13 as a transmission part. The first rotating member 10 is divided into a first fixed ring 11 and a first movable ring 12 that are both formed in an annular shape (or a cylindrical shape), and the first fixed ring 11 and the first movable ring 10 are divided. The ring 12 is connected to the ring 12 so as to be able to transmit power via the first transmission unit 13, in other words, to be integrally rotatable. The first rotating member 10 is rotatable about the first rotation center axis R <b> 1 as a whole as a combination of the first fixed ring 11 and the first movable ring 12. Similarly, the second rotating member 20 includes a second fixed ring 21 as a fixed portion, a second movable ring 22 as a movable portion, and a second transmission portion 23 as a transmission portion. The second rotating member 20 is divided into a second fixed ring 21 and a second movable ring 22 that are both formed in an annular shape (or a cylindrical shape), and the second fixed ring 21 and the second movable ring 22 are divided. The ring 22 is coupled to the ring 22 so as to be able to transmit power via the second transmission portion 23, in other words, to be integrally rotatable. The second rotating member 20 can rotate around the first rotation center axis R <b> 1 as a whole as a combination of the second fixed ring 21 and the second movable ring 22.

  The first rotating member 10, the first fixed ring 11, the first movable ring 12, the first transmission portion 13, the second fixed ring 21, the second movable ring 22, and the second transmission portion 23 of the second rotation member 20. Will be described in detail later.

  The first rotating member 10 and the second rotating member 20 have contact surfaces 14 and 24 in contact with the outer peripheral curved surface on the radially outer side of each planetary ball 50 on the first movable ring 12 and the second movable ring 22 described later, respectively. Have. The contact surfaces 14, 24 of the first rotating member 10 and the second rotating member 20 are, for example, a concave arc surface having a curvature equivalent to the curvature of the outer peripheral curved surface of the planetary ball 50, and a concave arc having a curvature different from the curvature of the outer peripheral curved surface. It has a shape such as a surface, a convex arc surface, or a flat surface. Here, each contact surface 14, 24 is in a state of a reference position described later (a state in which the first rotation center axis R 1 and the second rotation center axis R 2 are parallel), and the first rotation center in each planetary ball 50. The distance from the axis R1 to the contact portion with the planetary ball 50 is the same length, and the contact angles θ of the first rotating member 10 and the second rotating member 20 with respect to the planetary balls 50 are the same angle. It is trying to become.

  Here, the contact angle θ is an angle from the reference to the contact portion between the planetary ball 50 and the contact surfaces 14 and 24. Here, the radial direction is used as a reference. The contact surfaces 14 and 24 of the first rotating member 10 and the second rotating member 20 with the planetary ball 50 are in point contact or surface contact with the outer peripheral curved surface of the planetary ball 50. Further, the contact surfaces 14 and 24 of the first rotating member 10 and the second rotating member 20 with the planetary ball 50 are subjected to an axial force from the first rotating member 10 and the second rotating member 20 toward the planetary ball 50. In this case, a force (normal force Fn) is applied to the planetary ball 50 radially inward and in an oblique direction (normal force Fn).

  In the continuously variable transmission 1 of the present embodiment, since the outer diameters of the plurality of planetary balls 50 are different as described later, the contact angles θ between the plurality of planetary balls 50 are different.

  The continuously variable transmission 1 causes the first rotating member 10 to function as a torque input unit (input ring) when the continuously variable transmission 1 is driven forward (when torque is input to a rotating element as an input unit). The continuously variable transmission 1 causes the second rotating member 20 to function as a torque output unit (output ring) when the continuously variable transmission 1 is driven forward. In the continuously variable transmission 1, an input shaft 71 is connected to a first fixing ring 11 (described later) of the first rotating member 10 via a torque cam 70. In the continuously variable transmission 1, an output shaft 74 is connected to a later-described second fixing ring 21 of the second rotating member 20 via a torque cam 73. The input shaft 71 and the output shaft 74 are supported on the outer peripheral surface of the transmission shaft 60 via a radial bearing or the like so as to be relatively rotatable about the first rotation center axis R1 as a rotation center. The input shaft 71 is connected to the power source side of the vehicle, and the output shaft 74 is connected to the drive wheel side of the vehicle.

  The transmission shaft 60 exemplified here is fixed to a fixed portion of the continuously variable transmission 1 in a vehicle body or the like, and is a columnar fixed shaft configured not to rotate relative to the fixed portion.

  The torque cams 70 and 73 are torque axial force conversion mechanisms that convert rotational torque into axial force along the first rotation center axis R1. The torque cam 70 is disposed between the first rotating member 10 and the input shaft 71. The torque cam 73 is disposed between the second rotating member 20 and the output shaft 74. When the torque cam 70 transmits the rotational torque between the input shaft 71 and the first rotating member 10, each planet along the axial direction with respect to the first rotating member 10 according to the magnitude of the transmitted torque. A thrust (axial force) toward the ball 50 is generated. When the torque cam 73 transmits the rotational torque between the output shaft 74 and the second rotating member 20, each planet along the axial direction with respect to the second rotating member 20 according to the magnitude of the transmitted torque. A thrust (axial force) toward the ball 50 is generated.

  As shown in FIG. 2, the sun roller 30 has a cylindrical shape with a center axis coinciding with the first rotation center axis R1, and is supported by bearings RB1 and RB2 so as to be able to rotate relative to the transmission shaft 60 in the circumferential direction. Is done. That is, the sun roller 30 is disposed on the transmission shaft 60 so as to be relatively rotatable with respect to the transmission shaft 60, the first rotating member 10, the second rotating member 20, and carriers 40 and 41, which will be described later, about the first rotation center axis R1. Is done. Further, the sun roller 30 is positioned with respect to the axial direction of the transmission shaft 60 by the outer ring of the bearing RB1, the outer ring of the bearing RB2, and the like, and is fixed so as not to move relative to the axial direction of the transmission shaft 60.

  Further, the outer surface 31 of the sun roller 30 is in contact with the plurality of planetary balls 50. On the outer peripheral surface 31 of the sun roller 30, a plurality of planetary balls 50 are radially arranged at substantially equal intervals. Therefore, the outer surface 31 of the sun roller 30 becomes a rolling surface when the planetary ball 50 rotates. The sun roller 30 can roll (rotate) each planetary ball 50 by its own rotation, or it can rotate along with the rolling (rotational) movement of each planetary ball 50.

  The carriers 40 and 41 support the ends of the support shafts 51 that support the planetary balls 50 so as not to prevent the tilting motion of the planetary balls 50. The carriers 40 and 41 are, for example, disk-shaped members whose center axes coincide with the first rotation center axis R1, and are opposed to the axial direction of the first rotation center axis R1 with the planetary ball 50 interposed therebetween. Arranged. The carriers 40 and 41 can rotate relative to the first rotating member 10, the second rotating member 20, and the sun roller 30 around the first rotation center axis R <b> 1 as the rotation center. The carriers 40 and 41 hold the end portions of the support shafts 51 in a state in which the planetary balls 50 can be tilted. As described above, the carrier 40 is supported so as to be rotatable relative to the transmission shaft 60 with the first rotation center axis R1 as the rotation center. Here, the carrier 40 is supported on the outer peripheral surface of the transmission shaft 60 via a bearing RB3 and the like so as to be relatively rotatable about the first rotation center axis R1 as a rotation center. On the other hand, the carrier 41 is fixed to the transmission shaft 60 so as to be integrally rotatable. Therefore, the carrier 40 and the carrier 41 are configured to be relatively rotatable with the first rotation center axis R1 as the rotation center.

  The planetary ball 50 is a rolling member that rolls on the outer peripheral surface 31 of the sun roller 30. The planetary ball 50 is preferably a perfect sphere, but may have a spherical shape at least in the rolling direction, for example, a rugby ball having an elliptical cross section. The planetary ball 50 is rotatably supported by a support shaft 51 that passes through the center of the planetary ball 50. For example, the planetary ball 50 can be rotated relative to the support shaft 51 with the second rotation center axis R2 as the rotation axis (that is, rotation) by the radial bearings RB4 and RB5 disposed between the outer periphery of the support shaft 51. I am doing so. Therefore, the planetary ball 50 can roll on the outer peripheral surface 31 of the sun roller 30 around the support shaft 51. Both ends of the support shaft 51 protrude from the planetary ball 50 and are held by the carrier 40 and the carrier 41 in a state where the planetary ball 50 can be tilted.

  The relationship between the outer diameters and the arrangement positions of the plurality of planetary balls 50 will be described later in detail.

  The reference position of the support shaft 51 is a position where the second rotation center axis R2 is parallel to the first rotation center axis R1 (see FIG. 2). The support shaft 51 includes a reference position and a position inclined from the reference position in a tilt plane including the rotation center axis (second rotation center axis R2) and the first rotation center axis R1 formed at the reference position. Can be swung (tilted) together with the planetary ball 50. This tilt is performed with the center of the planetary ball 50 as a fulcrum in the tilt plane.

  In the continuously variable transmission 1, when the tilt angle of the planetary ball 50 is the reference position, that is, 0 degree, the first rotating member 10 and the second rotating member 20 rotate at the same rotational speed (same rotational speed). . 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 the planetary ball 50 is tilted from the reference position, the distance from the center axis of the support shaft 51 to the contact portion with the first rotating member 10 changes and the second axis from the center axis of the support shaft 51 changes. The distance to the contact portion with the rotating member 20 changes. Accordingly, either 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 50 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 respective rotating elements such as the first rotating member 10, the second rotating member 20, and the sun roller 30 is not changed by changing the tilt angle. Can be changed in stages.

  The continuously variable transmission 1 is provided with a transmission 80 as a mechanism for changing the speed ratio γ. The transmission 80 has a gear ratio by changing the contact point between the first rotating member 10 and the planetary ball 50 and the contact point between the second rotating member 20 and the planetary ball 50 by the tilting operation of the planetary ball 50. The rotation ratio between the rotating elements is changed. Since the gear ratio γ changes with a change in the tilt angle of the planetary ball 50, the transmission 80 tilts the planetary ball 50 by inclining the second rotation center axis R2 of each planetary ball 50. Use a tilting device. The transmission 80 is in a state where the second rotation center axis R2 of each planetary ball 50 is located in a plane including the first rotation center axis R1 and is parallel to the first rotation center axis R1 in the plane, that is, a reference It is comprised so that it can be tilted to the state which exists in a position, and the state which inclines from the parallel state. As this transmission 80, one known in this technical field is used. Here, the transmission 80 is of a type that tilts the planetary ball 50 together with the support shaft 51, for example, a carrier rotation type.

  Specifically, the transmission 80 applies a force to tilt the support shaft 51 according to the relative rotation of the carrier 40 and the carrier 41, that is, tilts the planetary ball 50 together with the support shaft 51. . Here, in the continuously variable transmission 1, an offset groove 42 is formed in the carrier 40 to guide the end of the support shaft 51 in the tilting direction when each planetary ball 50 tilts. A groove 43 is formed. As illustrated in FIG. 3, the offset groove portion 42 is formed in an arc shape along the circumferential direction in the carrier 40. A plurality of offset groove portions 42 are provided corresponding to each support shaft 51. The plurality of offset grooves 42 are formed radially with the first rotation center axis R1 as a whole. The guide groove 43 is formed linearly along the radial direction in the carrier 41. A plurality of guide groove portions 43 are provided corresponding to each support shaft 51. In the offset groove portion 42, one end portion in the axial direction of each support shaft 51 is inserted. The guide groove portion 43 is inserted with the other axial end portion of each support shaft 51. The offset groove portion 42 is in contact with the inner wall surface and the outer peripheral surface of one end portion in the axial direction of each support shaft 51, thereby supporting one end portion in the axial direction of each support shaft 51 and positioning it at a predetermined radial position. .

  In the transmission 80, for example, a driving device such as a motor is driven by the control of an electronic control unit (ECU), and the generated power is transmitted to the carrier 40 via a transmission member such as a worm gear, and the carrier 40 performs the first rotation. By displacing around the central axis R <b> 1, the carrier 40 is displaced relative to the carrier 41 in the circumferential direction. As a result, the transmission 80 shifts the phase of the offset groove 42 of the carrier 40 with respect to the guide groove 43 of the carrier 41, and the radial position (support position relative to the radial direction) of one end in the axial direction of each support shaft 51. ) Is pushed up or down with respect to the radial direction. As a result, the support shaft 51 has the second rotation center axis line relative to the first rotation center axis line R1 according to the deviation between the radial position of the end portion on the one axial side and the radial position of the end portion on the other axial side. The tilt angle that is the tilt angle of R2 is changed, and the planetary ball 50 tilts accordingly. The transmission 80 can tilt the planetary ball 50 by applying the tilting force to the support shaft 51 in this manner and tilting the support shaft 51 to tilt the second rotation center axis R2.

  In the continuously variable transmission 1 configured as described above, for example, when torque is transmitted from the input shaft 71 to the first rotating member 10, the magnitude of torque transmitted by the action of the torque cam 70, the torque cam 73, and the like is increased. Accordingly, a pressing force (pressing load) is generated in a direction in which the first rotating member 10 and each planetary ball 50, the second rotating member 20 and each planetary ball 50 are relatively approached and pressed against each other. As a result, the continuously variable transmission 1 has a transmission torque capacity corresponding to the pressing force, and between the first rotating member 10 and each planetary ball 50 according to this transmission torque capacity, each planetary ball 50 and the second planetary ball 50. A traction force (friction force) is generated between the rotating member 20 and the rotating member 20. As a result, the continuously variable transmission 1 can transmit power (torque) between the first rotating member 10 and each planetary ball 50 and between each planetary ball 50 and the second rotating member 20. .

  Further, the pressing force by the torque cam 70 and the torque cam 73 is caused by the action according to the shape and positional relationship between the contact surfaces 14 and 24 of the first rotating member 10 and the second rotating member 20 and the outer surface of each planetary ball 50. It is also transmitted to the sun roller 30 via the ball 50. Accordingly, the continuously variable transmission 1 generates a traction force (friction force) between each planetary ball 50 and the sun roller 30 according to the pressing force by the torque cam 70 and the torque cam 73, and each planetary ball 50 and the sun roller 30. Can transmit power (torque) to each other.

  Therefore, the continuously variable transmission 1 generates a frictional force (traction force) between the first rotating member 10 and each planetary ball 50 as the first rotating member 10 rotates, and each planetary ball 50 starts to rotate. . The continuously variable transmission 1 generates a frictional force between each planetary ball 50 and the second rotating member 20 and between each planetary ball 50 and the sun roller 30 due to the rotation of each planetary ball 50. The two-rotating member 20 and the sun roller 30 also start to rotate. Similarly, in the continuously variable transmission 1, each planetary ball 50 starts rotating as the second rotating member 20 rotates, and the first rotating member 10 and the sun roller 30 also start rotating. The continuously variable transmission 1 can change the speed ratio γ steplessly by the transmission 80 tilting each planetary ball 50 and changing the tilt angle of each planetary ball 50 as described above. it can.

  By the way, in the continuously variable transmission 1 of the present embodiment, there is a possibility that the surface pressure of the rotation transmitting portion may vary due to, for example, variations in the outer diameter of the planetary ball 50 due to manufacturing errors or the like. Here, the rotation transmission portion in the continuously variable transmission 1 typically includes a contact portion between the first rotating member 10 and each planetary ball 50 and a contact portion sun roller between the second rotating member 20 and each planetary ball 50. 30, each planetary ball 50, and a contact portion.

  FIG. 4 illustrates an example of the outer diameter and surface pressure calculation of the planetary ball 50. In this case, the surface pressure of the error planetary ball 50 having a relatively small diameter relative to the surface pressure of the ideal planetary ball 50 is relatively small, and the outer diameter of the error planetary ball 50 having a small diameter with respect to the ideal planetary ball 50 is not the same. If it exceeds a predetermined value, the contact point between the error planetary ball 50 and the first rotating member 10, the second rotating member 20, etc. is not formed. Then, as the surface pressure that the error planetary ball 50 takes on is reduced, the surface pressure of the ideal planetary ball 50 may be relatively higher than the ideal surface pressure when there is no variation.

  In order to eliminate such variations in surface pressure, the continuously variable transmission 1 according to the present embodiment arranges a plurality of planetary balls 50 having different outer diameters due to manufacturing errors and the like in a predetermined order, and the first rotating member 10. The second rotating member 20 is divided. Thereby, the continuously variable transmission 1 suppresses occurrence of variations in the surface pressure of the rotation transmission portion even when the outer diameter of the planetary ball 50 varies due to, for example, manufacturing errors.

  Specifically, as shown in FIG. 5, the plurality of planetary balls 50 have larger outer diameters in order from one side to the other side with respect to a specific direction along the direction orthogonal to the first rotation center axis R1. It is arranged to become. Here, the specific direction is any one of the radial directions orthogonal to the first rotation center axis R1.

  Here, as shown in FIG. 5, an example of selection and arrangement of the outer diameter of the planetary balls 50 will be described by taking a case where the continuously variable transmission 1 includes six planetary balls 50 as an example.

  The continuously variable transmission 1 illustrated in FIG. 5 includes planetary balls 50a, 50b, 50c, 50d, 50e, and 50f as six planetary balls 50. The planetary balls 50a, 50b, 50c, 50d, 50e, 50f are provided radially around the first rotation center axis R1 and are arranged at equal intervals around the first rotation center axis R1. Here, the continuously variable transmission 1 includes a planetary ball 50a, a planetary ball 50b, a planetary ball 50c, a planetary ball 50d, a planetary ball 50e, and a planetary ball 50f in the clockwise direction around the first rotation center axis R1 in FIG. It is arranged in the order. In the continuously variable transmission 1, the planetary ball 50a and the planetary ball 50d are positioned point-symmetrically with respect to the radial direction about the first rotation center axis R1, and the planetary ball 50b and the planetary ball 50e are opposed to each other. The planetary ball 50c and the planetary ball 50f face each other and are point-symmetrically positioned.

  Here, the planetary balls 50a, 50b, 50c, 50d, 50e, and 50f are the first set in which the planetary ball 50a and the planetary ball 50f are located on one side in a specific direction, and the planetary ball 50b and the planetary ball 50e are specified. The second set, which is located in the center of the direction, is distinguished into a third set where the planetary ball 50b and the planetary ball 50e are located on the other side in the specific direction. The planetary balls 50a, 50b, 50c, 50d, 50e, and 50f are a first set of the planetary ball 50a and the planetary ball 50f, the planetary ball 50b and the planetary ball 50e with respect to a specific direction orthogonal to the first rotation center axis R1. And the third set of planetary balls 50b and 50e are selected in order of the outer diameter. A predetermined manufacturing error is allowed for the outer diameter of the planetary ball 50 in each of the above groups.

  Regarding the selection of the outer diameter of each set of planetary balls 50, first, the plurality of planetary balls 50 before assembly are classified into a plurality of ranks according to the manufacturing accuracy of the outer diameter, and then the planetary balls in the same set are used. 50 is selected from the planetary balls 50 in the same rank. For example, as schematically shown in FIG. 6, the plurality of planetary balls 50 before assembling are classified into five ranks of rank 0, rank +1, rank +2, rank −1, and rank −2 according to the manufacturing error of the outer diameter. Are distinguished. In FIG. 6, the vertical axis represents the outer diameter [mm] of the planetary ball 50, and when the allowable manufacturing error of the plurality of planetary balls 50 as a whole is T2, the allowable manufacturing of the outer diameter within each rank. The error is assumed to be a tolerance value T0 that is smaller than T2. Here, the outer diameter of the planetary ball 50 increases in the order of rank +1 and rank +2 with respect to rank 0, and decreases in the order of rank -1 and rank -2.

  The first set of planetary balls 50a and 50f is selected from the same rank on the minus side. The second set of the planetary ball 50b and the planetary ball 50e is selected from rank 0, respectively. The third set of the planetary ball 50b and the planetary ball 50e is a rank on the plus side, and is selected from the same rank that is symmetrical with the first set with respect to rank 0. That is, as shown in selection example 1 in FIG. 6, the first set of planetary balls 50a and 50f is selected from within rank-1, and the second set of planetary balls 50b and 50e is The third set of planetary balls 50b and 50e is selected from within rank +1, respectively. Alternatively, as shown in selection example 2 in FIG. 6, the first set of planetary balls 50a and 50f is selected from within rank-2, and the second set of planetary balls 50b and 50e is The third set of the planetary ball 50b and the planetary ball 50e is selected from within rank +2, respectively.

  In this way, as shown in FIGS. 1, 5, and 7, the plurality of planetary balls 50 are sequentially removed from one side to the other side in a specific direction orthogonal to the first rotation center axis R1. The diameter is selected and arranged so as to increase. That is, the plurality of planetary balls 50 are in the order of a first set of planetary balls 50a and 50f, a second set of planetary balls 50b and 50e, and a third set of planetary balls 50b and 50e. Selection and arrangement are made so that the outer diameter becomes larger.

  And the continuously variable transmission 1 of this embodiment is the outer diameter arranged in the predetermined order because the 1st rotation member 10 and the 2nd rotation member 20 are made into a split structure, as shown in FIG. A portion including a contact portion with each different planetary ball 50 floats so as to be eccentric with respect to the first rotation center axis R <b> 1 of the transmission shaft 60.

  As described above, the first rotating member 10 is divided into the first fixed ring 11 and the first movable ring 12, and the first fixed ring 11 and the first movable ring 12 perform the first transmission. It is connected via the part 13 so that power can be transmitted. Similarly, the second rotating member 20 is divided into the second fixed ring 21 and the second movable ring 22 as described above, and the second fixed ring 21 and the second movable ring 22 are divided. The second transmission unit 23 is coupled so that power can be transmitted. Since the first rotating member 10 and the second rotating member 20 have a substantially symmetrical configuration with the planetary ball 50 sandwiched therebetween, in the following description, when it is not necessary to distinguish between them, Both will be explained together.

  The first fixed ring 11, the second fixed ring 21, the first movable ring 12, and the second movable ring 22 are annular members (rings) formed in an annular shape (or a cylindrical shape). The first fixing ring 11 and the second fixing ring 21 are fixing portions whose rotation center axis cannot swing with respect to the first rotation center axis R1. The first fixing ring 11 and the second fixing ring 21 are arranged in a state in which the rotation center axis is aligned with the first rotation center axis R1. The first fixing ring 11 and the second fixing ring 21 are portions to which the input shaft 71 and the output shaft 74 are connected via torque cams 70 and 73, respectively. On the other hand, the first movable ring 12 and the second movable ring 22 are movable parts whose rotation center axis can swing with respect to the first rotation center axis R1 and in contact with the planetary ball 50. As for the 1st movable ring 12 and the 2nd movable ring 22, the above-mentioned contact surfaces 14 and 24 are formed in an internal peripheral surface, respectively. The first movable ring 12 and the second movable ring 22 are disposed on the inner peripheral surface side of the first fixed ring 11 and the second fixed ring 21, respectively, and a part of the outer peripheral surface (protruding corner) is the first fixed ring 11. The second fixing ring 21 is disposed so as to contact the inner peripheral surface.

  The first transmission part 13 and the second transmission part 23 allow the inclination of the first movable ring 12 and the second movable ring 22 with respect to the first fixed ring 11 and the second fixed ring 21, respectively, Torque can be transmitted between the second fixed ring 21, the first movable ring 12, and the second movable ring 22. The 1st transmission part 13 of this embodiment and the 2nd transmission part 23 have spline engaging part 13a, 23a, respectively. The spline engaging portions 13a and 23a are spline engaged with the inner peripheral surfaces of the first fixed ring 11 and the second fixed ring 21 and the outer peripheral surfaces of the first movable ring 12 and the second movable ring 22, respectively. As a result, the spline engaging portions 13a and 23a can integrally rotate the first fixed ring 11, the second fixed ring 21, the first movable ring 12, and the second movable ring 22 along the first rotation center axis R1. It is connected so that it can move relative to the direction.

  The first transmission portion 13 and the second transmission portion 23 have a clearance C in the radial direction perpendicular to the first rotation center axis R1 of the spline engagement portions 13a and 23a with respect to the first fixing ring 11 and the second fixing ring 21. It is formed larger than the displacement due to the inclination of the first movable ring 12 and the second movable ring 22. The clearance C corresponds to a gap along the radial direction between the spline grooves and the spline protrusions constituting the spline engaging portions 13a and 23a. As a result, the first transmission portion 13 and the second transmission portion 23 are configured so that the first fixing ring 11 is rotated when the first rotating member 10 and the second rotating member 20 rotate about the first rotation center axis R1 as a whole. The inclination of the first movable ring 12 and the second movable ring 22 with respect to the second fixed ring 21 can be allowed. In addition, the first transmission unit 13 and the second transmission unit 23 generate torque (rotational power) between the first fixed ring 11 and the second fixed ring 21 and the first movable ring 12 and the second movable ring 22. In other words, it can be rotated integrally.

  The continuously variable transmission 1 configured as described above includes the first fixing ring 11, the second rotating member 20, and the second rotating member 20 as a whole when the first rotating member 10 and the second rotating member 20 rotate about the first rotation center axis R 1. While the two fixed rings 21 rotate about the first rotation center axis R1 as a rotation center, the rotation centers of the first movable ring 12 and the second movable ring 22 are eccentric in a state where they are inclined with respect to the first rotation center axis R1. Rotate. The eccentric amount D (see FIG. 5) of the first movable ring 12 and the second movable ring 22 with respect to the first fixed ring 11 and the second fixed ring 21 is the outer diameter of the plurality of planetary balls 50 as shown in FIG. The amount depends on the difference.

  That is, the continuously variable transmission 1 includes the first fixed ring 11 and the second fixed ring 11 due to the eccentricity of the first movable ring 12 and the second movable ring 22 with respect to the rotation centers of the first fixed ring 11 and the second fixed ring 21. The rotation centers of the fixed ring 21 and the first movable ring 12 and the second movable ring 22 are shifted. In the continuously variable transmission 1, when the first rotating member 10 and the second rotating member 20 are rotated, the contact tracks 15 and 25 between the planetary balls 50 and the contact surfaces 14 and 24 are indicated by dotted lines in FIG. It becomes like this. The contact tracks 15 and 25 are arranged outside the plurality of planetary balls 50 with respect to concentric circles (for example, the first fixing ring 11 and the second fixing ring 21 illustrated in FIG. 5) centered on the first rotation center axis R1. It will be eccentric according to the diameter difference.

  That is, as shown in FIG. 1, the contact tracks 15, 25 are arranged so that a plurality of planetary balls 50 have an outer diameter that increases in order along a specific direction and are fixed so as not to revolve with respect to the transmission shaft 60. And the tilt of the first movable ring 12 and the second movable ring 22 with respect to the first fixed ring 11 and the second fixed ring 21 is allowed, so that the radial direction orthogonal to the first rotation center axis R1 It becomes a trajectory inclined. More specifically, the contact tracks 15 and 25 approach the center position side of the planetary ball 50a with respect to the axial direction on the planetary ball 50a side with the smaller outer diameter, while moving in the axial direction on the planetary ball 50c side with the larger outer diameter. On the other hand, the orbit is separated from the center position side of the planetary ball 50c. As a result, the continuously variable transmission 1 is configured such that the first movable ring 12 and the second movable ring 22 are inclined with respect to the plurality of planetary balls 50 arranged so that the outer diameter increases in order along the specific direction. By tilting 15 and 25, the surface pressure of the rotation transmitting portion between each planetary ball 50 and the contact surfaces 14 and 24 is made uniform, and the occurrence of variations is suppressed.

  Then, the continuously variable transmission 1 detects the rotational trajectory shift between the first fixed ring 11, the second fixed ring 21 and the first movable ring 12, and the second movable ring 22 due to the shift of the rotation center. 2 It can be absorbed by the axial movement of the spline engaging portions 13a, 23a of the transmission portion 23.

  As a result, the continuously variable transmission 1 has a surface of a rotation transmitting portion such as a contact portion between the planetary ball 50 and the first rotating member 10 and the second rotating member 20 even if the production accuracy of the planetary ball 50 is lowered. Generation of variations in pressure can be suppressed, and surface pressure can be easily equalized. As a result, the continuously variable transmission 1 can, for example, reduce manufacturing costs, improve power transmission efficiency, and improve surface durability of the high surface pressure portion in the rotation transmission portion. Can do.

  Further, as shown in FIG. 1, the first fixing ring 11 and the second fixing ring 21 of the present embodiment are provided with curved surfaces 11a and 21a on the inner peripheral surface, respectively. The first movable ring 12 and the second movable ring 22 are provided on the inner peripheral surfaces of the first fixed ring 11 and the second fixed ring 21 in contact with the curved surfaces 11a and 21a. Here, the first movable ring 12 and the second movable ring 22 are also provided with curved surfaces at the contact portions with the curved surfaces 11a and 21a.

  The curved surfaces 11a and 21a are respectively the first fixed ring 11, the second fixed ring 21, the first movable ring 12 and the second movable ring 22, and the first fixed ring 11 and the second fixed ring 21. The first movable ring 12 and the second movable ring 22 are formed along the movement trajectory of the contact point. That is, the curved surfaces 11a and 21a are formed so as to coincide with the movement trajectory of the contact point between the first fixed ring 11 and the second fixed ring 21 and the first movable ring 12 and the second movable ring 22 accompanying the rotation. .

  In the continuously variable transmission 1, the rotation centers of the first movable ring 12 and the second movable ring 22 are inclined with respect to the rotation centers (first rotation center axis) of the first fixed ring 11 and the second fixed ring 21. Therefore, as the first rotating member 10 and the second rotating member 20 rotate, the position of the contact point between the first fixed ring 11, the second fixed ring 21, the first movable ring 12, and the second movable ring 22 is changed. Moving. The contact points of the first fixed ring 11, the second fixed ring 21, the first movable ring 12, and the second movable ring 22 are, for example, with respect to a position P1 on the planetary ball 50a side having a small outer diameter in FIG. The position P2 on the planetary ball 50c side with the large outer diameter moves to the axially outer side (the opposite side to the planetary ball 50) and the radially inner side. The curved surfaces 11 a and 21 a are contact points of the first fixed ring 11, the second fixed ring 21, the first movable ring 12, and the second movable ring 22 with the rotation of the first rotating member 10 and the second rotating member 20. The shape is adapted to the movement trajectory in the axial direction and radial direction.

  As a result, the continuously variable transmission 1 has the first fixed ring 11, the second fixed ring 21, and the first movable ring as the first rotating member 10 and the second rotating member 20 rotate by the action of the curved surfaces 11 a and 21 a. 12. When the contact point with the 2nd movable ring 22 moves, it can suppress inhibiting the said movement. That is, the continuously variable transmission 1 can smoothly guide the tilting movement of the first movable ring 12 and the second movable ring 22 with respect to the first fixed ring 11 and the second fixed ring 21 on the curved surfaces 11a and 21a. As a result, the surface pressure can be made more uniform.

  FIG. 8 is a diagram showing an example of the surface pressure of each planetary ball 50 between the continuously variable transmission 1 of the present embodiment and the continuously variable transmission according to the comparative example. In FIG. 8, the white graph represents the surface pressure in the continuously variable transmission 1 of the present embodiment, and the black graph represents the surface pressure in the continuously variable transmission according to the comparative example. In the continuously variable transmission 1 of the present embodiment, as described above, the plurality of planetary balls 50 are arranged so that the outer diameters increase in order along a specific direction, and the first fixing ring 11 and the second fixing ring 21 are arranged. In contrast, the first movable ring 12 and the second movable ring 22 are inclined and eccentric. On the other hand, in the continuously variable transmission according to the comparative example, the plurality of planetary balls 50 are arranged so that the outer diameters are increased in order along a specific direction, but the first fixed ring 11 and the second fixed ring 21 are different. The first movable ring 12 and the second movable ring 22 are fixed and are not eccentric. As is apparent from FIG. 8, the continuously variable transmission 1 of the present embodiment is different from the continuously variable transmission according to the comparative example in that the planetary ball 50, the first rotating member 10, the second rotating member 20, It can be understood that the variation in the surface pressure of the rotation transmitting portion such as the contact portion can be suppressed.

  The continuously variable transmission 1 according to the embodiment described above includes the transmission shaft 60, the first rotating member 10 and the second rotating member 20, the planetary ball 50, and the transmission 80. The transmission shaft 60 is the center of rotation. The first rotating member 10 and the second rotating member 20 are disposed so as to face the transmission shaft 60 in the axial direction, and can be relatively rotated about the common first rotation center axis R1. The planetary balls 50 are rotatable about a second rotation center axis R2 different from the first rotation center axis R1, and a plurality of planetary balls 50 are provided radially about the first rotation center axis R1. Torque can be transmitted between the first rotating member 10 and the second rotating member 20 sandwiched between the second rotating member 20. The transmission 80 can change the speed ratio, which is the rotational speed ratio between the first rotating member 10 and the second rotating member 20, by the tilting operation of the planetary ball 50. The plurality of planetary balls 50 are arranged such that the outer diameters increase in order from one side to the other side with respect to a specific direction along the direction orthogonal to the first rotation center axis R1. The first rotating member 10 and the second rotating member 20 have a first fixing ring 11 and a second fixing ring 21 whose rotation center axis cannot swing with respect to the first rotation center axis R1, respectively, and the rotation center axis. The first movable ring that can swing with respect to the first rotation center axis R <b> 1 and that contacts the planetary ball 50, the second movable ring 22, the first fixed ring 11, and the second fixed ring 21. 12. First transmission capable of transmitting torque between the first fixed ring 11 and the second fixed ring 21 and the first movable ring 12 and the second movable ring 22 while allowing the inclination of the second movable ring 22. Part 13 and a second transmission part 23.

  Therefore, the continuously variable transmission 1 is arranged such that the plurality of planetary balls 50 have an outer diameter increasing in order along a specific direction, and the first movable ring with respect to the first fixed ring 11 and the second fixed ring 21. 12. Since the second movable ring 22 is configured to be inclined and eccentric, it is possible to suppress variation in the surface pressure of the rotation transmission portion.

  The continuously variable transmission according to the above-described embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope described in the claims.

1 continuously variable transmission 10 first rotating member (first rotating element)
11 First fixing ring (fixing part)
11a, 21a Curved surface 12 First movable ring (movable part)
13 1st transmission part (transmission part)
13a, 23a Spline engaging portion 14, 24 Contact surface 15, 25 Contact track 20 Second rotating member (second rotating element)
21 Second fixing ring (fixing part)
22 Second movable ring (movable part)
23 Second transmission part (transmission part)
30 Sun Roller 40, 41 Carrier 50, 50a, 50b, 50c, 50d, 50e, 50f Planetary ball (rolling member)
51 Support shaft 60 Transmission shaft 80 Transmission device R1 First rotation center axis R2 Second rotation center axis

Claims (3)

A transmission shaft as a center of rotation;
A first rotation element and a second rotation element that are arranged opposite to the transmission shaft in the axial direction and are capable of relative rotation about a common first rotation center axis;
The second rotation center axis that is different from the first rotation center axis is rotatable about a rotation center, and a plurality of radial rotations are provided around the first rotation center axis, and the first rotation element and the second rotation element A rolling member that is sandwiched between and capable of transmitting torque between the first rotating element and the second rotating element;
A transmission capable of changing a transmission gear ratio, which is a rotation speed ratio between the rotating elements, by a tilting operation of the rolling member;
The plurality of rolling members are arranged such that an outer diameter increases in order from one side to the other side with respect to a specific direction along a direction orthogonal to the first rotation center axis.
The first rotation element and the second rotation element have a fixed portion whose rotation center axis cannot swing with respect to the first rotation center axis, and the rotation center axis is the first rotation center axis. Torque can be transmitted between the fixed part and the movable part while allowing the movable part to swing with respect to the rolling member and allowing the movable part to be inclined with respect to the fixed part. Having a transmission part,
Continuously variable transmission. The transmission portion includes a spline engaging portion that connects the fixed portion and the movable portion so as to be integrally rotatable and relatively movable in a direction along the first rotation center axis, and the spline engaging portion includes the spline engaging portion. The clearance with respect to the direction orthogonal to the first rotation center axis is formed larger than the displacement of the movable part with respect to the fixed part,
The continuously variable transmission according to claim 1. The fixed portion is formed in an annular shape or a disk shape, and a curved surface is provided on the inner peripheral surface,
The movable portion is provided in contact with the curved surface on the inner peripheral surface side of the fixed portion,
The curved surface is formed along a movement trajectory of the fixed part, the movable part, and the contact point with the rotation of the fixed part and the movable part.
The continuously variable transmission according to claim 1 or 2.

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