Continuously variable transmission

Abstract

To provide a continuously variable transmission which enables increase of transmission torque and easy change of a change gear ratio.SOLUTION: An output shaft 3 is disposed coaxially on one end portion side of an input shaft 2. A continuously variable transmission includes: a shift drum 34 disposed on the output shaft 3 side relative to a sun roller 2A; a carrier 4 disposed on the input shaft 2 side relative to the sun roller 2A; a first supporting unit 46 provided in the shift drum 34 and swingably supporting an end portion of a support shaft 16 on the output shaft 3 side; and a second supporting unit 47 provided in the carrier 4, swingably supporting an end portion of the support shaft 16 on the input shaft 2 side, and comprising a self-aligning bearing 17. The shift drum 34 and the carrier 4 are allowed to move in an axial direction of the input shaft 2 and prevented from rotating around the input shaft 2. The first supporting unit 46 includes a spherical guide roller 35 swingably held inside a groove 34A of the shift drum 34, and a bearing 54 provided in the guide roller 35.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a continuously variable transmission.

Background Art

[0002] As a continuously variable transmission that steplessly changes the power of a power source, the one described in Patent Document 1 is known. The continuously variable transmission described in Patent Document 1 includes a transmission ring having a center on the central axis of the input shaft and being movably provided in the direction of the central axis, and a plurality of planetary rollers that are arranged at equal intervals within a virtual conical surface having a vertex on the central axis, circumscribe the input rollers, and inscribe the output ring, and a second conical portion that inscribes the transmission ring. The continuously variable transmission also includes a movable holder that holds the plurality of planetary rollers rotatably about their respective rotation axes and revolvably about the central axis, and a loading cam mechanism that generates a thrust load in the direction of the central axis. By controlling the position of the transmission ring, continuous stepless shifting is achieved.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, in a continuously variable transmission using planetary rollers, it is desirable that the transmission torque be large. To increase the transmission torque, it is necessary to increase the contact pressure at the contact portions of the input rollers and the output ring with the planetary rollers, and increase the normal force at each contact portion. On the other hand, when the contact pressure is increased, a large operating force is required to change the positions of the contact portions of the input rollers and the output ring with the planetary rollers, and the transmission ratio cannot be easily changed.

[0005] However, in the continuously variable transmission described in Patent Document 1, since the operating force required to change the transmission ratio has not been studied, there has been a problem that the transmission ratio cannot be easily changed.

[0006] Therefore, an object of the present invention is to provide a continuously variable transmission that can increase the transmitted torque and can easily change the transmission ratio.

Means for Solving the Problems

[0007] To solve the above problems, the present invention includes an input member provided on an input shaft to which rotational power is input from a driving power source, an output member that transmits the rotational power input from the input member to an output shaft, a planetary cone having a conical surface in contact with the input member and the output member and formed in a frustum shape, a support shaft that rotatably supports the planetary cone and is movable in the axial direction, and by changing the contact position of the input member on the conical surface of the planetary cone and the contact position of the output member on the conical surface of the planetary cone, a continuously variable transmission mechanism that steplessly changes the rotational power of the input shaft to the output shaft via the planetary cone, and a continuously variable transmission comprising: the output shaft is coaxially arranged on one end side of the input shaft; a shift drum arranged on the output shaft side of the input member in the axial direction of the input shaft; a carrier arranged on the input shaft side of the input member in the axial direction of the input shaft; a first support portion provided on the shift drum that swingably supports the end portion of the support shaft on the output shaft side; a second support portion provided on the carrier that swingably supports the end portion of the support shaft on the input shaft side; the shift drum and the carrier are movable in the axial direction of the input shaft and are provided so as not to be rotatable around the input shaft; the first support portion includes a spherical guide roller swingably held in a groove formed in the shift drum and a bearing provided inside the guide roller; the second support portion includes a self-aligning bearing held by the carrier. Further, a guide groove extending in the axial direction of the input shaft is formed in the carrier, and a guide follower fixed by a bolt inserted into the transmission case in a direction substantially perpendicular to the input shaft abuts on the guide groove. The guide follower restricts rotation of the carrier around the input shaft and guides movement of the carrier in the axial direction of the input shaft. It is characterized by this.

Effects of the Invention

[0008] Thus, according to the present invention, it is possible to provide a continuously variable transmission that can increase the transmission torque and can easily change the transmission ratio.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0010] A continuously variable transmission according to an embodiment of the present invention includes an input member provided on an input shaft to which rotational power is input from a driving power source, an output member that transmits the rotational power input from the input member to an output shaft, a planetary cone having a conical surface in contact with the input member and the output member and formed in a frustum shape, a support shaft that rotatably supports the planetary cone and is movable in the axial direction, and a moving mechanism that variably speeds the rotational power of the input shaft to the output shaft steplessly by changing the contact position of the input member on the conical surface of the planetary cone and the contact position of the output member on the conical surface of the planetary cone. The continuously variable transmission is provided such that the output shaft is coaxially arranged on one end side of the input shaft, a shift drum arranged on the output shaft side of the input member in the axial direction of the input shaft, a carrier arranged on the input shaft side of the input member in the axial direction of the input shaft, a first support portion provided on the shift drum and swingably supporting the end portion on the output shaft side of the support shaft, and a second support portion provided on the carrier and swingably supporting the end portion on the input shaft side of the support shaft. The shift drum and the carrier are movable in the axial direction of the input shaft and are provided so as not to rotate around the input shaft. The first support portion includes a spherical guide roller swingably held in a groove formed in the shift drum and a bearing provided inside the guide roller. The second support portion includes a self-aligning bearing held by the carrier. According to this, the continuously variable transmission according to an embodiment of the present invention can increase the transmitted torque and can easily change the transmission ratio.

Example

[0011] Hereinafter, a continuously variable transmission according to an embodiment of the present invention will be described with reference to the drawings.

[0012] Figs. 1 to 4 are diagrams showing a continuously variable transmission according to an embodiment of the present invention. The directions (up, down, left, and right) used in the description are for convenience of explanation. The cross-sectional views of Figs. 1 to 3 are cross-sectional views of the upper side of the continuously variable transmission according to an embodiment of the present invention, and the up and down directions used in the description follow this drawing. That is, regarding the lower side not shown, the up and down arrangement relationship is reversed. In other words, with reference to the rotation center axis of the input shaft, the direction away from the rotation center axis of the input shaft in the radial direction is described as upward, and conversely, the direction approaching the rotation center axis of the input shaft is described as downward. The left and right directions also follow the drawing. That is, the side where the input shaft 2 to which the driving force source is connected is arranged is the right side, and this direction is also referred to as the input side and the input shaft side. Conversely, the side where the output shaft 3 to which the driving wheel is connected is arranged is the left side, and this direction is also referred to as the output side and the output shaft side. Fig. 4 is a diagram for explaining the planetary cone 5 viewed from above, and the front and rear directions in this figure follow the coordinate indication of the drawing.

[0013] First, the configuration will be described. In Fig. 1, the continuously variable transmission 1 is mounted on a vehicle and transmits the rotational power of a driving force source 10 such as an internal combustion engine or a motor to a driving wheel (not shown) by continuously varying the speed.

[0014] The continuously variable transmission 1 includes a transmission case 41, an input shaft 2 to which rotational power is input from the driving force source 10, a sun roller 2A as an input member attached to the input shaft 2, a ring roller 6 as an output member that transmits the rotational power input from the sun roller 2A to the output shaft 3, and the output shaft 3.

[0015] Further, the continuously variable transmission 1 includes a carrier 4, a plurality of planetary cones 5 having conical surfaces 14d and 15d in contact with the sun roller 2A and the ring roller 6 and formed in a frustum shape, and a support shaft 16 that rotatably supports the planetary cones 5 and is movable in the axial direction.

[0016] Further, the continuously variable transmission 1 is provided with a moving mechanism 30. The moving mechanism 30 moves the planetary cone 5 along the axial direction of the input shaft 2, and changes the contact position P1 of the sun roller 2A on the conical surface 14d of the planetary cone 5 and the contact position P2 of the ring roller 6 on the conical surface 15d of the planetary cone 5. By this change, the continuously variable transmission 1 continuously varies the rotational power of the input shaft 2 through the planetary cone 5 and outputs it to the output shaft 3.

[0017] The transmission case 41 is composed of a right case 42 and a left case 43 connected to the left end portion of the right case 42 by bolts 41A. Inside the transmission case 41, each member described later that constitutes the continuously variable transmission 1 and traction oil are accommodated.

[0018] The input shaft 2 extends in the left - right direction, and a driving power source 10 is connected to the right end of the input shaft 2. An annular enlarged - diameter portion 2a protruding in the radial direction is formed at the central portion in the longitudinal direction of the input shaft 2, and a sun roller 2A is attached to the outer periphery of this enlarged - diameter portion 2a by bolts 2b. The sun roller 2A has an annular shape coaxial with the input shaft 2 and is formed with a large diameter so as to protrude from the input shaft 2.

[0019] Note that the axis 2r along the input shaft 2 extending in the left - right direction is the rotation center axis of the input shaft 2, and the input shaft 2 rotates about the axis 2r. The direction of the axis 2r is referred to as the axial direction.

[0020] The output shaft 3 is provided coaxially with the axis 2r of the input shaft 2. Specifically, the output shaft 3 is arranged coaxially on the left - end side of the input shaft 2. The output shaft 3 includes a cylindrical shaft portion 3A protruding from the left case 43, a disk - shaped enlarged - diameter portion 3B extending radially outward from the right end of the shaft portion 3A, a large - diameter cylindrical large - diameter portion 3C extending rightward from the outer peripheral end of the enlarged - diameter portion 3B and into which the left end portion of the input shaft 2 is inserted, and a disk - shaped enlarged - diameter portion 3D extending radially outward from the right end of the large - diameter portion 3C. The shaft portion 3A, the enlarged - diameter portions 3B, 3D, and the large - diameter portion 3C are composed of one member.

[0021] The output shaft 3 further has a cylindrical output drum 3E. The output drum 3E is arranged coaxially with the input shaft 2, extends rightward from the radially outer peripheral edge of the diameter-expanded portion 3D, and expands in diameter in a direction away from the input shaft 2 radially as it goes rightward. An annular ring roller 6 is attached to the large-diameter side end portion that is the right end of the output drum 3E by bolts 6a.

[0022] The output drum 3E is composed of a separate member from the shaft portion 3A, the diameter-expanded portions 3B and 3D, and the large-diameter portion 3C. The small-diameter side end portion that is the left end of the output drum 3E is connected to and integrated with the diameter-expanded portion 3D. That is, the output shaft 3 has a joining structure in which the output drum 3E among the respective constituent members is configured separately from other members. Thereby, the workability of the manufacturing operation of the output shaft 3 can be improved, and the productivity of the output shaft 3 can be improved.

[0023] A final drive gear (not shown) is attached to the shaft portion 3A of the output shaft 3, and the final drive gear meshes with the final driven gear of a differential device (not shown). The differential device is connected to the left and right drive wheels via left and right drive shafts (not shown). The differential device distributes the rotational power of the drive power source 10 transmitted from the output shaft 3 to the left and right drive shafts and transmits it to the left and right drive wheels.

[0024] The carrier 4 is arranged around the input shaft 2. The carrier 4 holds a support shaft 16 that rotatably (self-rotates) supports a plurality of planetary cones 5. That is, the input shaft 2 is arranged so as to penetrate the carrier 4, and the plurality of planetary cones 5 are arranged so as to surround the input shaft 2.

[0025] The carrier 4 holds the support shaft 16 via the self-aligning bearing 17. The self-aligning bearing 17 has an outer ring 17a, spherical bodies 17b, and an inner ring 17c that is rotatably connected to the outer ring 17a via the spherical bodies 17b. The self-aligning bearing 17 is composed of a self-aligning ball bearing using the spherical bodies 17b. The self-aligning bearing 17 swingably supports the end portion 16A (right end portion) on the input shaft 2 side of the support shaft 16 attached to its inner ring 17c. The self-aligning bearing 17 supports the support shaft 16 so as not to be displaced in the direction of the axis 16r of the support shaft 16. The self-aligning bearing 17 constitutes the second support portion 47.

[0026] In FIG. 2, a shift flange 32 described later is in contact with the inner peripheral surface of the carrier 4 via a ball spline 4c. The ball spline 4c restricts relative rotation around the input shaft 2 between the carrier 4 and the shift flange 32 and allows relative movement in the axial direction of the input shaft 2. The shift flange 32 is arranged so as to penetrate the carrier 4, and the input shaft 2 is arranged so as to penetrate the shift flange 32. That is, the shift flange 32 is arranged so as to surround the input shaft 2 on the inner diameter side of the carrier 4.

[0027] The carrier 4 is arranged on the input shaft 2 side (right side) of the sun roller 2A in the axial direction of the input shaft 2. A guide groove 40 extending in the axial direction of the input shaft 2 and open to the outer diameter side (outer side) is formed on the outer circumference of the carrier 4. And a guide follower 45 fixed to the transmission case 41 is arranged in the internal space of the guide groove 40, and the guide follower 45 is in contact with the guide groove 40. The guide follower 45 is fixed to the transmission case 41 by a bolt 44 inserted from the outside along a direction substantially perpendicular to the input shaft 2. The guide follower 45 and the guide groove 40 restrict the rotation of the carrier 4 with respect to the transmission case 41 and allow and guide the movement of the carrier 4 in the axial direction of the input shaft 2. The guide follower 45 is configured similarly to a ball bearing and has a contact portion 45A corresponding to the outer ring of the ball bearing and contacting the guide groove 40. And by reducing the frictional resistance of the contact portion between the guide follower 45 and the guide groove 40 due to the rotation of the contact portion 45A, the carrier 4 can easily move in the extending direction of the guide groove 40.

[0028] In this way, since the rotation of the input shaft 2 of the carrier 4 is restricted by the guide follower 45 that abuts within the guide groove 40, the shift flange 32 connected to the carrier 4 via the ball spline 4c is also restricted from rotating with respect to the transmission case 41. Further, the carrier 4 is allowed and guided to move in the axial direction of the input shaft 2 by the guide groove 40 and the ball spline 4c. Note that the guide follower 45 disposed in the internal space of the guide groove 40 is fixed to the transmission case 41 by screwing the male thread formed on the bolt 44 and the female thread formed on the guide follower 45. That is, the bolt 44 and the guide follower 45 are fixed to the transmission case 41 by screwing together and sandwiching the transmission case 41. Also, the diameter of the hole of the transmission case 41 through which the bolt 44 is inserted is formed larger than the diameter of the bolt 44, and a gap is provided between the transmission case 41 and the bolt 44. Therefore, within the range of the gap, the positions of the bolt 44 and the guide follower 45 with respect to the transmission case 41 can be finely adjusted. That is, the position of the guide follower 45 can be finely adjusted according to the position of the guide groove 40 of the carrier 4.

[0029] Note that a restricting portion 32A that protrudes radially outward is formed at the left end portion of the outer peripheral surface of the shift flange 32. Also, a circlip 32B that protrudes radially outward is attached to the right end portion of the outer peripheral surface of the shift flange 32. When the relative movement amount of the carrier 4 in the axial direction of the input shaft 2 with respect to the shift flange 32 increases, the restricting portion 32A and the circlip 32B come into contact with the carrier 4, and further relative movement of the carrier 4 is restricted. That is, restricting portions 32A and circlips 32B that limit the movement range of the carrier 4 are disposed on both sides in the axial direction of the ball spline 4c on the shift flange 32.

[0030] In FIG. 1, the planetary cone 5 is supported by the carrier 4 and the shift drum 34 via the support shaft 16. The carrier 4 is disposed on the input shaft 2 side with respect to the sun roller 2A in the axial direction of the input shaft 2 with respect to the planetary cone 5. The shift drum 34 is disposed on the output shaft 3 side with respect to the sun roller 2A in the axial direction of the input shaft 2 with respect to the planetary cone 5. A needle bearing 63 is held on the inner peripheral side of the shift drum 34, and the needle bearing 63 rotatably supports the input shaft 2. That is, the input shaft 2 is disposed to penetrate the shift drum 34, and the shift drum 34 is supported by the input shaft 2 via the needle bearing 63 so as to be relatively rotatable.

[0031] The planetary cone 5 has a frustum-shaped input-side planetary cone 14 with which the sun roller 2A contacts, and a frustum-shaped output-side planetary cone 15 that is provided separately from the input-side planetary cone 14 and with which the ring roller 6 contacts. The input-side planetary cone 14 and the output-side planetary cone 15 are supported by the support shaft 16 so as to be relatively rotatable with respect to the support shaft 16 in a posture where the bottom surfaces 14b and 15b of both face each other. That is, the input-side planetary cone 14 and the output-side planetary cone 15 are rotatably attached to the support shaft 16 in opposite directions so that the bottom surfaces face each other. The input-side planetary cone 14 and the output-side planetary cone 15 are supported by the support shaft 16 so as to be movable in the direction of the axis 16r within the range of the self-aligning bearing 17 at the end of the support shaft 16 and the guide roller 35. In the assembled state, the position of the input-side planetary cone 14 on the output shaft 3 side (left end side) of the support shaft 16 is restricted by contacting the sun roller 2A, and the position of the output-side planetary cone 15 on the input shaft 2 side (right end side) of the support shaft 16 is restricted by contacting the ring roller 6.

[0032] The planetary cone 5 has a ball cam mechanism 21 between the input-side planetary cone 14 and the output-side planetary cone 15. The ball cam mechanism 21 connects the bottom surface 14b of the input-side planetary cone 14 and the bottom surface 15b of the output-side planetary cone 15 to transmit power from the input-side planetary cone 14 to the output-side planetary cone 15, or from the output-side planetary cone 15 to the input-side planetary cone 14.

[0033] The ball cam mechanism 21 has a plurality of input-side cam grooves 14f formed on the bottom surface 14b of the input-side planetary cone 14, a plurality of output-side cam grooves 15f formed on the bottom surface 15b of the output-side planetary cone 15, and a sphere 20 accommodated so as to span the input-side cam grooves 14f and the output-side cam grooves 15f. The same number of input-side cam grooves 14f and output-side cam grooves 15f are formed and extend along the circumferential direction centered on the axis 16r of the support shaft 16.

[0034] The input-side cam grooves 14f and the output-side cam grooves 15f have an arc shape with a radius dimension the same as the radius dimension of the sphere 20 in the cross-sectional shape along the radial direction centered on the axis 16r of the support shaft 16. For this reason, the sphere 20 disposed in the space sandwiched between the input-side cam grooves 14f and the output-side cam grooves 15f does not move in the radial direction centered on the axis 16r of the support shaft 16. And the input-side cam grooves 14f and the output-side cam grooves 15f are each formed such that the depth changes in the circumferential direction. Specifically, the input-side cam grooves 14f and the output-side cam grooves 15f are formed in a shape that is deep at the center in the circumferential direction and gradually shallows as approaching both ends in the circumferential direction from the center in the circumferential direction. That is, the input-side cam grooves 14f and the output-side cam grooves 15f are formed shallower toward the ends in the circumferential direction. And the sphere 20 is freely rollable in the circumferential direction along the input-side cam grooves 14f and the output-side cam grooves 15f, and the radial groove width dimension of the input-side cam grooves 14f and the output-side cam grooves 15f centered on the axis 16r of the support shaft 16 is set to be approximately the same as the dimension of the sphere 20 (the cross-sectional dimension when cut by the bottom surfaces 14b, 15b of the planetary cones 5) that abuts against the groove bottom at that position. For this reason, the groove widths of the input-side cam grooves 14f and the output-side cam grooves 15f are formed in a shape that is wide at the center in the circumferential direction and gradually narrows as approaching both ends in the circumferential direction from the center in the circumferential direction.

[0035] The input-side cam groove 14f and the output-side cam groove 15f are formed at positions facing each other when the bottom surfaces 14b and 15b are combined, and their shapes are the same. Also, the input-side planetary cone 14 and the output-side planetary cone 15 are formed in the same shape. That is, the input-side planetary cone 14 and the output-side planetary cone 15 have the same shape and are compatible, improving productivity.

[0036] In other words, the planetary cone 5 can form a planetary cone 5 of the same shape by swapping the input-side planetary cone 14 with the output-side planetary cone 15 and swapping the output-side planetary cone 15 with the input-side planetary cone 14.

[0037] The input-side planetary cone 14 is configured to transmit power to the output-side planetary cone 15 via the sphere 20. The sphere 20 is composed of, for example, a steel ball, but is not limited to a steel ball.

[0038] In this embodiment, the dimensional tolerance is set so as to provide a gap at the contact position P1 between the conical surface 14d of the input-side planetary cone 14 of the planetary cone 5 and the sun roller 2A, and the dimensional tolerance is set so as to provide a gap at the contact position P2 between the conical surface 15d of the output-side planetary cone 15 of the planetary cone 5 and the ring roller 6. That is, the dimensions of each part are set so that the contact positions P1 and P2 do not become press-fits. Thereby, the assembling work of the planetary cone 5 to the continuously variable transmission 1 can be easily performed.

[0039] In the planetary cone 5, when power is input from the sun roller 2A to the input-side planetary cone 14, due to the torque difference, the input-side planetary cone 14 and the output-side planetary cone 15 rotate relative to each other temporarily so that the positions in the rotation direction are shifted. That is, when power is input from the sun roller 2A to the input-side planetary cone 14, due to the contact between the output-side planetary cone 15 and the ring roller 6 or the inertia due to the self-weight of the output-side planetary cone 15, a state occurs temporarily where the rotation of the output-side planetary cone 15 lags behind the rotation of the input-side planetary cone 14. As a result, the relative position in the rotation direction between the input-side planetary cone 14 and the output-side planetary cone 15 is shifted, and the sphere 20 moves (rolls) inside the input-side cam groove 14f and the output-side cam groove 15f. When the sphere 20 moves (rolls) inside the input-side cam groove 14f and the output-side cam groove 15f, the ball cam mechanism 21 acts. In this case, the input-side planetary cone 14 and the output-side planetary cone 15 are separated in the axial direction of the support shaft 16 by the sphere 20.

[0040] That is, when the sphere 20 moves, the positions of the input-side cam groove 14f and the output-side cam groove 15f with which the sphere 20 abuts change, and the sphere 20 is displaced to places with different depths. Therefore, the protruding amount of the sphere 20 from the input-side cam groove 14f and the output-side cam groove 15f changes, and the input-side planetary cone 14 and the output-side planetary cone 15 move away from or approach each other in the axial direction of the support shaft 16.

[0041] That is, when the depths of the input-side cam groove 14f and the output-side cam groove 15f where the sphere 20 is located become shallower, the input-side planetary cone 14 and the output-side planetary cone 15 move away from each other in the axial direction of the support shaft 16, and when the relative movement in the rotation direction between the input-side planetary cone 14 and the output-side planetary cone 15 subsides, they rotate integrally via the sphere 20. This situation is when the transmitted torque increases, the input-side planetary cone 14 and the output-side planetary cone 15 move away from each other in the axial direction of the support shaft 16, and the input-side planetary cone 14 and the sun roller 2A, and the output-side planetary cone 15 and the ring roller 6 come into stronger contact, enabling large torque transmission.

[0042] On the other hand, when the depths of the input-side cam groove 14f and the output-side cam groove 15f where the sphere 20 is located become deeper, the input-side planetary cone 14 and the output-side planetary cone 15 approach in the axial direction of the support shaft 16, and the relative movement in the rotational direction between the input-side planetary cone 14 and the output-side planetary cone 15 subsides, and they rotate integrally via the sphere 20. This situation is when the transmitted torque decreases. The input-side planetary cone 14 and the output-side planetary cone 15 approach in the axial direction of the support shaft 16, the force pressing the input-side planetary cone 14 against the sun roller 2A, and the force pressing the output-side planetary cone 15 against the ring roller 6 become weaker, and the pressing force unnecessary for torque transmission can be eliminated, improving durability.

[0043] The input-side planetary cone 14 and the output-side planetary cone 15 are connected via the ball cam mechanism 21 and rotate integrally about the axis 16r of the support shaft 16, except for the relative movement (shift) due to the torque difference.

[0044] Note that even when the input-side planetary cone 14 and the output-side planetary cone 15 are in the state of being farthest apart in the axial direction of the support shaft 16, the sphere 20 does not come out of the input-side cam groove 14f and the output-side cam groove 15f. In other words, the input-side planetary cone 14 and the output-side planetary cone 15 move in the axial direction of the support shaft 16 within a range of a distance smaller than the diameter of the sphere 20.

[0045] Also, both ends in the circumferential direction of the input-side cam groove 14f and the output-side cam groove 15f function as stoppers that contact the sphere 20 and restrict further displacement (relative rotation angle) between the input-side planetary cone 14 and the output-side planetary cone 15.

[0046] The planetary cone 5 has an elastic member 5A provided in a compressed state between the bottom surface 14b of the input-side planetary cone 14 and the bottom surface 15b of the output-side planetary cone 15. The elastic member 5A is composed of, for example, a disc spring or a wave washer, and generates a restoring force when compressed. Even when the planetary cone 5 is not transmitting torque, the biasing force (restoring force) of the elastic member 5A presses the input-side planetary cone 14 against the sun roller 2A and presses the output-side planetary cone 15 against the ring roller 6. Thereby, it is possible to prevent the input-side planetary cone 14 from idling with respect to the sun roller 2A, and it is possible to prevent the output-side planetary cone 15 from idling with respect to the ring roller 6, and the planetary cone 5 can transmit torque without slipping. That is, when power is input from the sun roller 2A to the input-side planetary cone 14, regardless of the magnitude of the inertia due to the self-weight of the output-side planetary cone 15, the force from the ring roller 6 in contact therewith can immediately cause relative rotation between the input-side planetary cone 14 and the output-side planetary cone 15, and the ball cam mechanism 21 can be actuated. Note that the elastic member 5A is attached to the input-side planetary cone 14 or the output-side planetary cone 15, and its shape and installation position are determined so as to avoid interference with the input-side cam groove 14f, the output-side cam groove 15f, and the sphere 20 so as not to affect the operation of the ball cam mechanism 21.

[0047] The end portion 16B (left end portion) of the support shaft 16 on the output shaft 3 side is swingably supported by the first support portion 46. The first support portion 46 is composed of a spherical guide roller 35 swingably held in a groove 34A formed in the shift drum 34 and a bearing 54 provided inside the guide roller 35. The bearing 54 is a needle bearing and supports the end portion 16B of the support shaft 16 with respect to the guide roller 35. The groove 34A formed in the shift drum 34 is a spiral groove formed so as to gently wind around the input shaft 2, and is formed so as to be displaced in the circumferential direction as the input shaft 2 is displaced in the axial direction. And the groove 34A not only swingably holds the guide roller 35, but also slightly moves the guide roller 35 in the circumferential direction of the input shaft 2 as the shift drum 34 is displaced in the axial direction of the input shaft 2.

[0048] The support shaft 16 is installed in an inclined posture with respect to the axis 2r of the input shaft 2 such that the axis 16r of the support shaft is inclined with respect to the axis 2r of the input shaft 2. Specifically, the axis 16r of the support shaft 16 is installed to be inclined with respect to the axis 2r of the input shaft 2 such that its central axis approaches the input shaft 2 as it goes leftward.

[0049] The planetary cone 5 moves in the direction of the axis 2r of the input shaft 2 together with the shift drum 34, the shift drum holding member 33, the shift flange 32, and the carrier 4 when the shift drum 34 is moved in the direction of the axis 2r of the input shaft 2 by the movement mechanism 30.

[0050] A plurality of planetary cones 5 are provided at equal intervals in the circumferential direction so as to surround the input shaft 2 on the outer side in the radial direction of the input shaft 2. Thereby, the normal forces acting on the sun roller 2A and the ring roller 6 from each planetary cone 5 can cancel each other out. In addition, in the continuously variable transmission 1 according to an embodiment of the present invention, an odd number of planetary cones 5 are provided. Thereby, since there are not a plurality of support shafts 16 on the plane including the axis 2r of the input shaft 2, the degree of freedom in installing the planetary cones 5 is improved.

[0051] The sun roller 2A is in contact with the conical surface 14d of the input-side planetary cone 14, and the ring roller 6 is in contact with the conical surface 15d of the output-side planetary cone 15.

[0052] The input-side planetary cone 14 is installed in a posture such that the generatrix of its conical surface 14d extends parallel to the axis 2r of the input shaft 2 to form a conical surface that is always in contact with the sun roller 2A.

[0053] The output-side planetary cone 15 is installed in a posture such that the generatrix of its conical surface 15d extends parallel to the axis 2r of the input shaft 2 to form a conical surface that is always in contact with the ring roller 6.

[0054] That is, even if the planetary cone 5 moves in the direction of the axis 2r of the input shaft 2, it moves in the direction of the axis 2r of the input shaft 2 while maintaining a posture such that the conical surface that is always in contact with the sun roller 2A and the conical surface that is always in contact with the ring roller 6 are parallel to the axis 2r of the input shaft 2. Therefore, the contact between the conical surface 14d and the sun roller 2A is maintained, and the contact between the conical surface 15d and the ring roller 6 is maintained.

[0055] As shown in FIG. 2, the moving mechanism 30 includes a shift operation portion 31 connected to the shift drum 34. The shift operation portion 31 is operated from the outside by an actuator or the like to move the shift drum 34 in the axial direction of the input shaft 2.

[0056] The moving mechanism 30 further includes a shift flange 32 and a shift drum holding member 33. The shift flange 32 is provided on the outer peripheral side of the shift operation portion 31 and on the inner peripheral side of the carrier 4, and moves in the axial direction of the input shaft 2 when the shift operation portion 31 is operated. The shift drum holding member 33 connects the shift flange 32 and the shift drum 34 so as to be integrally movable in the axial direction of the input shaft 2. The shift drum holding member 33 is a columnar member arranged so as to extend in the axial direction of the input shaft 2 between the planetary cones 5, and a plurality of them are provided. Here, the carrier 4 is provided so as to be movable in the axial direction of the input shaft 2 by the guide follower 45 and the guide groove 40 and not rotatable around the input shaft 2. Further, the shift flange 32 is movable in the axial direction of the input shaft 2 by the carrier 4 via the ball spline 4c and not rotatable around the input shaft 2. Therefore, the shift drum 34 connected to the shift flange 32 by the shift drum holding member 33 is also provided so as to be movable in the axial direction of the input shaft 2 and not rotatable around the input shaft 2.

[0057] The speed change operation unit 31 has an operation unit 31A in the form of a disk portion that spreads in the radial direction, and a shaft portion 31B on whose outer peripheral surface a feed screw is formed. Further, the shift flange 32 is formed in an annular shape so as to surround the outer peripheral portion of the shaft portion 31B of the speed change operation unit 31. A feed screw that engages with the shaft portion 31B is formed on the inner peripheral surface of the shift flange 32. A shift drum holding member 33 is connected to the left end portion of the shift flange 32. The shift drum holding member 33 is formed in a rod shape that passes above the sun roller 2A from the shift flange 32 and extends leftward. The left end portion of the shift drum holding member 33 is connected to the shift drum 34.

[0058] In the moving mechanism 30, when the speed change operation unit 31 is rotationally operated from the outside, the shift flange 32 is moved in the axial direction of the input shaft 2 by the feed screw mechanism. Then, the shift drum 34 connected to the shift flange 32 via the shift drum holding member 33 moves in the axial direction of the input shaft 2 integrally with the shift flange 32. When the shift drum 34 moves, the position of the groove 34A of the shift drum 34 with respect to the guide roller 35 changes. As described above, the groove 34A is formed as a spiral groove around the input shaft 2, and the position of the guide roller 35 is slightly moved in the circumferential direction of the input shaft 2 as the shift drum 34 is displaced in the axial direction. Then, the support shaft 16 tilts in the torsional direction with respect to the input shaft 2, and the planetary cone 5 changes its posture and tilts (skews). The tilted (skewed) planetary cone 5 receives a force in the direction to cancel the tilt of the support shaft 16, and the guide roller 35 moves in the groove 34A of the shift drum 34 to cancel the tilt, and the movement ends when the tilt is canceled. The position of the guide roller 35 where the tilt is canceled is the position in the groove 34A where the guide roller 35 was located before the shift drum 34 moved. This movement automatically occurs immediately when the shift drum 34 moves. Therefore, it seems as if the guide roller 35 held by the shift drum 34 moves together with the shift drum 34, and the planetary cone 5 moves in the same direction. At this time, the carrier 4 moves in the same direction accompanying the movement of the planetary cone 5 separately from the shift flange 32 by the ball spline 4c. In this embodiment, the carrier 4 moves to a position where the tilt is canceled by the component force generated by the tilt of the planetary cone 5 caused by the movement of the shift flange 32.

[0059] In this embodiment, the shift flange 32 moves axially by means of a feed screw mechanism. However, the shift flange 32 may be directly moved axially by an actuator without using the feed screw mechanism. Similarly, when the shift drum 34 moves axially in the other direction, the planetary cone 5 moves, and accordingly, the carrier 4 moves in the moving direction of the shift drum 34 following the planetary cone 5. Due to these functions, the posture and arrangement of the planetary cone 5 are appropriately maintained, and the positions of the shift drum 34 and the carrier 4 are adjusted accordingly. Therefore, the components that define the positional relationship between the first support portion 46 and the second support portion 47 can be made unnecessary, facilitating dimensional management during component manufacturing and improving productivity.

[0060] The operation portion 31A of the shift operation portion 31 is disposed outside the transmission case 41. The shaft portion 31B of the shift operation portion 31 is disposed inside the transmission case 41 and surrounds the outer peripheral surface of the input shaft 2.

[0061] A seal member 64 is provided between the inner peripheral surface of the operation portion 31A and the outer peripheral surface of the input shaft 2. A seal member 65 is provided between the outer peripheral surface of the right end portion of the shaft portion 31B of the shift operation portion 31 and the inner peripheral surface of the right end portion of the transmission case 41. Further, a seal member 66 is provided between the outer peripheral surface of the shaft portion 3A of the output shaft 3 and the inner peripheral surface of the left end portion of the transmission case 41. These seal members 64, 65, and 66 prevent the leakage of traction oil from the inside of the transmission case 41 to the outside and prevent the intrusion of foreign matter from the outside of the transmission case 41 to the inside.

[0062] A ball bearing 61 is provided between the inner peripheral surface of the right end portion of the shaft portion 31B of the shift operation portion 31 and the outer peripheral surface of the input shaft 2. A ball bearing 62 is provided between the inner peripheral surface of the left end portion of the shaft portion 31B of the shift operation portion 31 and the outer peripheral surface of the input shaft 2.

[0063] In the vicinity of the right end portion of the shaft portion 31B of the speed change operation unit 31 and on the left side of the seal member 65, a ball bearing 53 is provided. The ball bearing 53 has spherical rolling elements 53b, an outer ring 53a and an inner ring 53c that are relatively rotatable via the rolling elements 53b. The inner ring 53c of the ball bearing 53 is fitted to the shaft portion 31B and is axially prevented from coming off by a circlip 53d attached to the shaft portion 31B. The outer ring 53a of the ball bearing 53 is fitted to the inner peripheral surface of the right end portion of the transmission case 41.

[0064] Thus, in this embodiment, the speed change operation unit 31 is rotatably supported with respect to the transmission case 41 by the ball bearing 53. Further, the portion on the right end side of the input shaft 2 is rotatably supported with respect to the speed change operation unit 31 by the ball bearings 61 and 62.

[0065] In the continuously variable transmission 1 of this embodiment, the contact position P1 between the conical surface 14d of the planetary cone 5 and the sun roller 2A and the contact position P2 between the conical surface 15d of the planetary cone 5 and the ring roller 6 are at the same position in the axial direction of the input shaft 2. In other words, the sun roller 2A and the ring roller 6 are located on the same cross section perpendicular to the axis of the input shaft 2 and face each other in the radial direction of the input shaft 2. For this reason, except for the aforementioned tilting (skew) state, a rotational moment that tilts the axis 16r of the planetary cone 5 does not occur due to the contact pressure of the sun roller 2A and the ring roller 6.

[0066] In the continuously variable transmission 1 of this embodiment, the contact position P1 between the conical surface 14d of the planetary cone 5 on the sun roller 2A and the contact position P2 between the conical surface 15d of the planetary cone 5 on the ring roller 6 each extend substantially parallel to the input shaft 2. That is, the contact surfaces of the sun roller 2A and the ring roller 6 with respect to the planetary cone 5 have a cylindrical shape that extends substantially parallel to the input shaft 2.

[0067] The continuously variable transmission 1 of this embodiment includes a ball bearing 50. The ball bearing 50 has an outer ring 50a fitted to the transmission case 41, and an inner ring 50c connected to the outer ring 50a via spherical rolling elements 50b and fitted to the outer peripheral surface of the output shaft 3. The outer ring 50a is fitted to the inner peripheral surface of a cylindrical bearing holding portion 43A formed near the left end portion of the transmission case 41. Further, the inner ring 50c is fitted to the outer peripheral surface of a cylindrical large-diameter portion 3C formed on the output shaft 3.

[0068] Also, the continuously variable transmission 1 includes a tapered roller bearing 51. The tapered roller bearing 51 has an outer ring 51a fitted to the inner peripheral surface of the output shaft 3, and an inner ring 51c connected to the outer ring 51a via roller (a roller having a conical surface) - shaped rolling elements 51b and fitted to the outer peripheral surface of the input shaft 2. The outer ring 51a is fitted to the inner peripheral surface of the large-diameter portion 3C of the output shaft 3. The inner ring 51c is fitted to the outer peripheral surface of a cylindrical bearing holding member 51d attached to the left end portion of the input shaft 2. The bearing holding member 51d restricts the rightward movement of the inner ring 51c. The right end portion of the inner ring 51c abuts against the left end portion of the enlarged-diameter portion 3D of the bearing holding member 51d. The rolling elements 51b are inclined so as to bear an axial load in a direction bringing the input shaft 2 and the output shaft 3 closer. In this way, the tapered roller bearing 51 bears the axial and radial loads acting between the input shaft 2 and the output shaft 3. Therefore, the tapered roller bearing 51 also bears the axial and radial loads acting between the sun roller 2A and the ring roller 6. In particular, it can effectively receive the load generated in the axial direction of the input shaft 2 during the aforementioned tilting (skew) state and the load generated in the axial direction of the input shaft 2 during the operation of the ball cam mechanism 21.

[0069] Furthermore, the continuously variable transmission 1 includes a preload applying member 52. The preload applying member 52 is provided in a compressed state between the ball bearing 50 and the transmission case 41. The preload applying member 52 is composed of a diaphragm spring, a wave washer, or the like, and biases the ball bearing 50 in the axial direction of the input shaft 2 so as to apply a preload to the tapered roller bearing 51. Also, the preload applying member 52 suppresses the axial play of the input shaft 2 of the continuously variable transmission 1, improving productivity.

[0070] Specifically, the preload applying member 52 is provided between the left end portion of the outer ring 50a of the ball bearing 50 and a disk-shaped preload applying member holding portion 43B that is continuous with the right end portion of the bearing holding portion 43A of the transmission case 41. The restoring force of the preload applying member 52 presses the output shaft 3 to the right via the ball bearing 50. As a result, a leftward force acts on the outer ring 51a of the tapered roller bearing 51, and this force acts as a preload on the tapered roller bearing 51. Also, since the preload applying member 52 biases the transmission case 41 to the left, it suppresses the axial displacement of the transmission case 41 due to a leftward load, and suppresses the generation of noise and vibration due to the displacement of the transmission case 41.

[0071] When the preload applying member 52 is composed of a diaphragm spring, by designing the preload applying member 52 so that the preload on the tapered roller bearing 51 has a peak-like load characteristic, even when there is a variation in the axial position tolerance of the ball bearing 50, a stable preload can be applied to the tapered roller bearing 51.

[0072] Next, the operation of the continuously variable transmission 1 will be described. The rotational power of the drive power source 10 is transmitted to the input shaft 2 of the continuously variable transmission 1, and is transmitted from the sun roller 2A integrated with the input shaft 2 to the input-side planetary cone 14. Since the ball cam mechanism 21 is provided between the input-side planetary cone 14 and the output-side planetary cone 15, after the rotational power of the drive power source 10 is transmitted from the input-side planetary cone 14 to the output-side planetary cone 15 via the sphere 20, the rotational power is transmitted from the output-side planetary cone 15 to the ring roller 6. That is, the rotation of the sun roller 2A causes the planetary cone 5 to rotate together with the support shaft 16, and the rotational power of the planetary cone 5 is transmitted to the ring roller 6.

[0073] When the rotational power is transmitted from the output-side planetary cone 15 to the ring roller 6, the rotational power is transmitted from the output shaft 3 to the final driven gear of the differential device via the final drive gear, and then the rotational power is transmitted from the differential device to the left and right drive wheels via the left and right drive shafts.

[0074] In the continuously variable transmission 1, the rotational force (driving force) is transmitted as follows, and at the same time, the speed change (conversion of the rotational speed) is performed. The rotational speed of the sun roller 2A is transmitted to the input-side planetary cone 14, and the planetary cone 5 rotates at the speed changed by the ratio between the radius dimension of the sun roller 2A and the radius dimension of the contact portion on the input-side planetary cone 14. The rotational speed of the planetary cone 5 is transmitted to the ring roller 6. At this time, the ring roller 6 rotates at the speed changed by the ratio between the radius dimension of the ring roller 6 and the radius dimension of the contact portion on the planetary cone 5.

[0075] For example, when the planetary cone 5 is moved to the position farthest from the shaft portion 3A of the output shaft 3 (the rightmost position within the movable range of the planetary cone 5) by the moving mechanism 30, as shown in FIG. 1, the sun roller 2A contacts the smallest-diameter conical surface 14d of the input-side planetary cone 14. At this time, the ring roller 6 contacts the largest-diameter conical surface 15d on the bottom surface 15b side of the output-side planetary cone 15. As a result, the rotational speed of the sun roller 2A is increased by the planetary cone 5 and transmitted to the ring roller 6. This is the state where the speed ratio of the continuously variable transmission 1 is the smallest.

[0076] On the other hand, when the planetary cone 5 is moved by the movement mechanism 30 to the position closest to the shaft portion 3A of the output shaft 3 (the leftmost position within the movable range of the carrier 4), as shown in FIG. 3, the sun roller 2A contacts the conical surface 14d with the largest diameter on the bottom surface 14b side of the input-side planetary cone 14. At this time, the ring roller 6 contacts the conical surface 15d with the smallest diameter of the output-side planetary cone 15. Thereby, the rotational speed of the sun roller 2A is decelerated by the planetary cone 5 and transmitted to the ring roller 6. This is the state where the speed ratio is the largest in the continuously variable transmission 1.

[0077] That is, the continuously variable transmission 1 can continuously vary the rotational speed (rotational power) of the input shaft 2 to the output shaft 3 via the planetary cone 5 by changing the contact position P1 between the conical surface 14d of the input-side planetary cone 14 and the sun roller 2A and the contact position P2 between the conical surface 15d of the output-side planetary cone 15 and the ring roller 6 by the carrier 4.

[0078] During the movement of the planetary cone 5 by the movement mechanism 30, the planetary cone 5 temporarily changes its posture and tilts (skews). However, due to the swing of the guide roller 35 in the groove 34A of the shift drum 34, the action of the self-aligning bearing 17, and the propulsive force that suppresses the tilt so that the skew angle becomes minimum, the carrier 4 moves axially on the shift flange 32. For this reason, the planetary cone 5 automatically returns to the position where the skew angle is minimum. Specifically, as shown in FIG. 4, the position of the line forming the contact surface between the planetary cone 5 and the ring roller temporarily displaces from the position L1 when not tilted to the position L2 when tilted. Further, a normal force F1 acts on the planetary cone 5 in the circumferential direction of the input shaft 2 (see FIG. 1) when not tilted, and a normal force F2 including a component force F3 in the axial direction of the input shaft 2 (see FIG. 1) acts when tilted. And the component force F3 of the normal force F2 when tilted acts to eliminate the tilt of the planetary cone 5, moves the planetary cone 5 and the carrier 4 in the axial direction of the input shaft 2 (leftward in FIG. 4), and eliminates the tilt.

[0079] Note that a traction oil film (not shown) is formed at the contact position P1 between the sun roller 2A and the conical surface 14d of the input-side planetary cone 14, and at the contact position P2 between the ring roller 6 and the conical surface 15d of the output-side planetary cone 15. Thereby, power is transmitted from the sun roller 2A to the input-side planetary cone 14 through the oil film, and power is transmitted from the ring roller 6 to the output-side planetary cone 15 through the oil film.

[0080] Further, the input-side planetary cone 14 is installed such that its conical surface 14d extends parallel to the axis 2r of the input shaft 2 and is always in contact with the sun roller 2A. Also, the output-side planetary cone 15 is installed such that its conical surface 15d extends parallel to the axis 2r of the input shaft 2 and is always in contact with the ring roller 6.

[0081] Thereby, during gear shifting, the planetary cone 5 can be moved parallel to the conical surfaces 14d and 15d with respect to the sun roller 2A and the ring roller 6, and excessive frictional force can be suppressed from occurring between the sun roller 2A and the conical surface 14d, and between the ring roller 6 and the conical surface 15d. Therefore, smooth gear shifting can be performed.

[0082] Since the input-side planetary cone 14 and the output-side planetary cone 15 have the same outer diameter shape and the same cam groove shape, when the torque input to the input-side planetary cone 14 is small, the sphere 20 is located at the deepest position at the center in the circumferential direction of the input-side cam groove 14f and the output-side cam groove 15f of the input-side planetary cone 14. That is, the input-side planetary cone 14 and the output-side planetary cone 15 are in the closest position.

[0083] In this case, the input-side planetary cone 14 and the output-side planetary cone 15 rotate integrally. In this state, torque is transmitted from the input-side planetary cone 14 to the output-side planetary cone 15 through the sphere 20.

[0084] This state is during light load, and the contact surface pressure between the conical surface 14d of the input-side planetary cone 14 and the sun roller 2A, and the contact surface pressure between the conical surface 15d of the output-side planetary cone 15 and the ring roller 6 are adjusted to appropriate surface pressures that do not cause slippage. This is largely due to the elastic member 5A.

[0085] On the other hand, when the torque input to the input-side planetary cone 14 increases (that is, when it becomes difficult for the output-side planetary cone 15 to rotate relative to the rotation of the input-side planetary cone 14), the output-side planetary cone 15 begins to lag behind the input-side planetary cone 14. That is, the entire planetary cone 5 is in a twisted state. That is, the output-side planetary cone 15 cannot follow the rotation of the input-side planetary cone 14, and the input-side planetary cone 14 is relatively displaced in the rotational direction with respect to the output-side planetary cone 15.

[0086] Power is transmitted between the input-side planetary cone 14 and the output-side planetary cone 15 via the sphere 20. Due to this relative displacement, the sphere 20 moves from the deep part (the center in the circumferential direction) to the shallow part (one side in the circumferential direction) of the input-side cam groove 14f and the output-side cam groove 15f, and the input-side planetary cone 14 and the output-side planetary cone 15 move away from each other in the axial direction of the support shaft 16.

[0087] This is because the input-side cam groove 14f and the output-side cam groove 15f act like cam slopes on the sphere 20, so repulsive forces and movements corresponding to the torque like a torque cam occur.

[0088] As a result, the input-side planetary cone 14 and the output-side planetary cone 15 move away from each other in the direction on the support shaft 16.

[0089] Therefore, the contact surface pressure between the conical surface 14d of the input-side planetary cone 14 and the sun roller 2A, and the contact surface pressure between the conical surface 15d of the output-side planetary cone 15 and the ring roller 6 increase according to the torque (input load) transmitted by the planetary cone 5.

[0090] Note that, instead of making the shape of the change in the groove depth in the input-side cam groove 14f and the output-side cam groove 15f a simple inclination angle, the inclination may be changed so that the inclination becomes larger as it goes from the circumferential center portion to the circumferential end portion in the circumferential direction of the input-side cam groove 14f and the output-side cam groove 15f.

[0091] Since the sphere 20 is located at the circumferential center portion of the input-side cam groove 14f and the output-side cam groove 15f, when the input-side planetary cone 14 is twisted in the direction opposite to the above-described rotational direction with respect to the output-side planetary cone 15, the sphere 20 can be moved from the circumferential center portion of the input-side cam groove 14f and the output-side cam groove 15f to the side opposite to the above-described direction, and the input-side planetary cone 14 and the output-side planetary cone 15 can be separated in the axial direction of the support shaft 16.

[0092] Next, the effects of the continuously variable transmission 1 of the present embodiment will be described.

[0093] In the continuously variable transmission 1 of the present embodiment, the output shaft 3 is coaxially arranged on one end side of the input shaft 2. The continuously variable transmission 1 includes a shift drum 34 arranged on the output shaft 3 side of the sun roller 2A in the axial direction of the input shaft 2, a carrier 4 arranged on the input shaft 2 side of the sun roller 2A in the axial direction of the input shaft 2, a first support portion 46 provided on the shift drum 34 for swingably supporting the end portion on the output shaft 3 side of the support shaft 16, and a second support portion 47 provided on the carrier 4 for swingably supporting the end portion on the input shaft 2 side of the support shaft 16.

[0094] The shift drum 34 and the carrier 4 are movable in the axial direction of the input shaft 2 and are provided so as not to be rotatable around the input shaft 2. The first support portion 46 includes a spherical guide roller 35 swingably held in a groove 34A formed in the shift drum 34 and a bearing 54 provided inside the guide roller 35. The second support portion 47 includes a self-aligning bearing 17 held by the carrier 4.

[0095] Accordingly, when the shift drum 34 is moved in the axial direction of the input shaft 2 to change the gear ratio, the swing of the guide roller 35 in the groove 34A of the shift drum 34 and the centering action of the self-aligning bearing 17 absorb the temporary tilting (skew) of the planetary cone 5, and the planetary cone 5 and the carrier 4 can be moved to appropriate positions in the axial direction of the input shaft 2.

[0096] That is, even when the transmitted torque is large, when changing the gear ratio, the contact positions of the contact positions P1 and P2 are automatically changed by the movement accompanying the change in the posture of the planetary cone 5. Therefore, the planetary cone 5 can be moved in the axial direction of the input shaft 2 with a small operating force on the moving mechanism 30. As a result, the gear ratio can be easily changed without being greatly affected by the transmitted torque.

[0097] In the continuously variable transmission 1 of the present embodiment, the moving mechanism 30 includes a shift operation portion 31 connected to the shift drum 34. The shift operation portion 31 moves the shift drum 34 in the axial direction of the input shaft 2 when operated from the outside.

[0098] As a result, when the shift operation portion 31 is operated, the shift drum 34 moves in the axial direction of the input shaft 2, and the axial position of the planetary cone 5 changes. Therefore, the gear ratio can be changed steplessly.

[0099] In the continuously variable transmission 1 of the present embodiment, the moving mechanism 30 is provided on the outer peripheral side of the shift operation portion 31 and on the inner peripheral side of the carrier 4. The moving mechanism 30 includes a shift flange 32 that moves in the axial direction of the input shaft 2 when the shift operation portion 31 is operated, and a shift drum holding member 33 that connects the shift flange 32 and the shift drum 34 so as to be integrally movable in the axial direction of the input shaft 2. The shift flange 32 is supported by the carrier 4 so as to be movable in the axial direction of the input shaft 2 and non-rotatable around the input shaft 2.

[0100] As a result, in a state where the planetary cone 5 is tilted (skewed), the swinging of the guide roller 35 in the groove 34A of the shift drum 34, the action of the self-aligning bearing 17, and the driving force that suppresses the tilting so that the skew is minimized cause the carrier 4 to move on the shift flange 32. Therefore, the planetary cone 5 can be stopped at a position where the skew is minimized, and the skew can be eliminated. Further, since the axial position of the planetary cone 5 changes as the shift drum 34 moves axially, the transmission ratio can be changed steplessly.

[0101] In the continuously variable transmission 1 of the present embodiment, a guide groove 40 extending in the axial direction of the input shaft 2 is formed in the carrier 4. A guide follower 45 fixed by a bolt 44 inserted from the outside into the transmission case 41 in a direction substantially perpendicular to the input shaft 2 abuts on the guide groove 40. The guide follower 45 restricts the rotation of the carrier 4 around the input shaft 2 and guides the movement of the carrier 4 in the axial direction of the input shaft 2.

[0102] As a result, the carrier 4 can be supported so as not to rotate with respect to the transmission case 41. Further, by inserting the bolt 44 in a direction substantially perpendicular to the input shaft 2, it is possible to prevent the bolt 44 from loosening in its axial direction due to contact with the guide groove 40.

[0103] In the continuously variable transmission 1 of the present embodiment, the planetary cone 5 includes an input-side planetary cone 14 in contact with the sun roller 2A, an output-side planetary cone 15 provided separately from the input-side planetary cone 14 and in contact with the ring roller 6, and an elastic member 5A provided in a compressed state between the bottom surface 14b of the input-side planetary cone 14 and the bottom surface 15b of the output-side planetary cone 15.

[0104] Accordingly, dimensional tolerances are set so as to provide a gap at the contact position P1 between the conical surface 14d of the input-side planetary cone 14 of the planetary cone 5 and the sun roller 2A, and dimensional tolerances are set so as to provide a gap at the contact position P2 between the conical surface 15d of the output-side planetary cone 15 of the planetary cone 5 and the ring roller 6. Then, it can be assembled to the transmission case 41 in a state where the elastic member 5A is compressed. Therefore, the assemblability of the planetary cone 5 can be improved.

[0105] Also, by providing the elastic member 5A in a compressed state between the input-side planetary cone 14 and the output-side planetary cone 15, the restoring force of the elastic member 5A allows the conical surface 14d of the input-side planetary cone 14 to always contact the sun roller 2A to transmit torque, and the conical surface 15d of the output-side planetary cone 15 to always contact the ring roller 6 to transmit torque. Further, even when gaps occur between the conical surface 14d of the input-side planetary cone 14 and the sun roller 2A, and between the conical surface 15d of the output-side planetary cone 15 and the ring roller 6 due to manufacturing tolerances, centrifugal force during rotation, etc., the restoring force of the elastic member 5A can eliminate each gap.

[0106] In the continuously variable transmission 1 of the present embodiment, the planetary cone 5 has a ball cam mechanism 21 that connects the bottom surface 14b of the input-side planetary cone 14 and the bottom surface 15b of the output-side planetary cone 15 to transmit power from the input-side planetary cone 14 to the output-side planetary cone 15. The ball cam mechanism 21 has an input-side cam groove 14f formed on the bottom surface 14b of the input-side planetary cone 14, an output-side cam groove 15f formed on the bottom surface 15b of the output-side planetary cone 15, and a sphere 20 accommodated in the input-side cam groove 14f and the output-side cam groove 15f. The input-side cam groove 14f and the output-side cam groove 15f extend in the circumferential direction centered on the axis 16r of the support shaft 16, and the input-side cam groove 14f and the output-side cam groove 15f are formed shallower toward the circumferential ends.

[0107] Regarding this ball cam mechanism 21, when the accelerator is operated by the driver of the vehicle, a difference occurs in the torque acting on each of the input-side planetary cone 14 and the output-side planetary cone 15, and a rotation direction shift occurs between the input-side planetary cone 14 and the output-side planetary cone 15. Therefore, the sphere 20 moves within the gap sandwiched between the input-side cam groove 14f and the output-side cam groove 15f. As a result, since the sphere 20 expands the gap between the input-side planetary cone 14 and the output-side planetary cone 15, an appropriate normal force (pressing force) corresponding to the input torque is generated between the input-side planetary cone 14 and the sun roller 2A, and between the output-side planetary cone 15 and the ring roller 6, and torque transmission can be appropriately performed.

[0108] In the continuously variable transmission 1 of the present embodiment, the contact position P1 between the conical surface 14d of the planetary cone 5 and the sun roller 2A and the contact position P2 between the conical surface 15d of the planetary cone 5 and the ring roller 6 are at the same position in the axial direction of the input shaft 2.

[0109] This can prevent the generation of a rotational moment in the direction of rotating the support shaft 16 closer to the inner or outer side in the radial direction of the input shaft 2 by the normal forces acting on the conical surfaces 14d and 15d of the planetary cone 5, on the self-aligning bearings 17 at both ends of the support shaft 16 and the bearing 54. Therefore, it is possible to prevent the durability of the self-aligning bearings 17 and the bearing 54 from being reduced due to the rotational moment acting on the support shaft 16.

[0110] Also, since the contact position of the planetary cone 5 with respect to the sun roller 2A and the ring roller 6 can be changed without applying a rotational moment to the support shaft 16, the planetary cone 5 can be moved in the axial direction of the input shaft 2 with a small operating force on the moving mechanism 30, and the planetary cone 5 can be moved in the axial direction of the input shaft 2 to change the gear ratio without reducing the power transmission efficiency due to the generation of an excessive normal force.

[0111] As a result, it is possible to prevent the durability of the self-aligning bearings 17 and the bearing 54 that support the planetary cone 5 from being reduced, and it is possible to prevent the power transmission efficiency from being reduced.

[0112] Although embodiments of the present invention have been disclosed, it is obvious that those skilled in the art can make changes without departing from the scope of the present invention. It is intended that all such modifications and equivalents be included in the following claims.

Explanation of Signs

[0113] 1...Continuously variable transmission, 2...Input shaft, 2A...Sun roller (input member), 3...Output shaft, 5...Planetary cone, 5A...Elastic member, 6...Ring roller (output member), 10...Driving force source, 14...Input side planetary cone, 14b...Bottom surface, 14d...Conical surface, 14f...Input side cam groove, 15...Output side planetary cone, 15b...Bottom surface, 15d...Conical surface, 15f...Output side cam groove, 16...Support shaft, 16r...Axis, 17...Self-aligning bearing, 20...Sphere, 21...Ball cam mechanism, 30...Moving mechanism, 31...Shift operation unit, 32...Shift flange, 33...Shift drum holding member, 34...Shift drum, 34A...Groove, 35...Guide roller, 40...Guide groove, 41...Transmission case, 44...Bolt, 45...Guide follower, 46...First support portion, 47...Second support portion, 54...Bearing, P1, P2...Contact positions

Claims

1. An input member provided on an input shaft to which rotational power is input from a driving power source, an output member that transmits the rotational power input from the input member to an output shaft, a planetary cone having a conical surface where the input member and the output member are in contact and formed in a frustum shape, a support shaft that rotatably supports the planetary cone and is movably supported in the axial direction, a transmission mechanism that steplessly changes the rotational power of the input shaft to the output shaft via the planetary cone by changing the contact position of the input member on the conical surface of the planetary cone and the contact position of the output member on the conical surface of the planetary cone, and a continuously variable transmission comprising: the output shaft is coaxially arranged on one end side of the input shaft, a shift drum arranged on the output shaft side of the input member in the axial direction of the input shaft, a carrier arranged on the input shaft side of the input member in the axial direction of the input shaft, a first support portion provided on the shift drum that swingably supports the end portion of the support shaft on the output shaft side, a second support portion provided on the carrier that swingably supports the end portion of the support shaft on the input shaft side, the shift drum and the carrier are movably arranged in the axial direction of the input shaft and are provided so as not to be rotatable around the input shaft, the first support portion includes a spherical guide roller swingably held in a groove formed in the shift drum and a bearing provided inside the guide roller, the second support portion consists of a self-aligning bearing held by the carrier, a guide groove extending in the axial direction of the input shaft is formed in the carrier, a guide follower fixed by a bolt inserted into the transmission case in a direction substantially perpendicular to the input shaft abuts against the guide groove, the guide follower restricts the rotation of the carrier around the input shaft and guides the movement of the carrier in the axial direction of the input shaft, and a continuously variable transmission characterized by this.

2. The transmission mechanism is provided with a shift operation portion connected to the shift drum, the continuously variable transmission according to claim 1, wherein the shift operation portion is operated from the outside to move the shift drum in the axial direction of the input shaft.

3. The transmission mechanism is a shift flange provided on the outer peripheral side of the shift operation portion and on the inner peripheral side of the carrier, and moves in the axial direction of the input shaft when the shift operation portion is operated. A shift drum holding member that connects the shift flange and the shift drum so as to be integrally movable in the axial direction of the input shaft. The continuously variable transmission according to claim 2, wherein the shift flange is supported by the carrier so as to be movable in the axial direction of the input shaft and non-rotatable around the input shaft.

4. The planetary cone is An input-side planetary cone with which the input member contacts, An output-side planetary cone provided separately from the input-side planetary cone and with which the output member contacts, The continuously variable transmission according to any one of claims 1 to 3, further comprising an elastic member provided in a compressed state between the bottom surface of the input-side planetary cone and the bottom surface of the output-side planetary cone.

5. The planetary cone has a ball cam mechanism that connects the bottom surface of the input-side planetary cone and the bottom surface of the output-side planetary cone to transmit power from the input-side planetary cone to the output-side planetary cone. The ball cam mechanism is An input-side cam groove formed on the bottom surface of the input-side planetary cone, An output-side cam groove formed on the bottom surface of the output-side planetary cone, And spheres accommodated in the input-side cam groove and the output-side cam groove. The input-side cam groove and the output-side cam groove extend in the circumferential direction centered on the axis of the support shaft. The continuously variable transmission according to claim 4, wherein the input-side cam groove and the output-side cam groove are formed shallower toward the circumferential ends.

6. The continuously variable transmission according to any one of claims 1 to 5, wherein the contact position between the conical surface of the planetary cone and the input member and the contact position between the conical surface of the planetary cone and the output member are at the same position in the axial direction of the input shaft.

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