Continuously variable transmission

Abstract

To provide a continuously variable transmission capable of improving productivity, durability and reliability.SOLUTION: In a continuously variable transmission 1, a ball cam mechanism 21 comprises: an input side cam groove 14f formed on a bottom face 14b of an input side planet cone 14; an output side cam groove 15f formed on a bottom face 15b of an output side planet cone 15; a sphere 20 housed between the input side cam groove 14f and the output side cam groove 15f; and a retainer 22 arranged between the input side cam groove 14f and the output side cam groove 15f and holding the sphere 20. The input side cam groove 14f and the output side cam groove 15f extends in a circumferential direction and a radial direction with an axial core of a support shaft 16 as a center, and is formed as shallow as a circumferential end and outside in the radial direction. The retainer 22 holds the sphere 20 movably in the radial direction of a planet cone 5.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] A continuously variable transmission that uses a cone-shaped planetary cone to change the speed of the power of a driving force source steplessly is described in Patent Document 1. The continuously variable transmission described in Patent Document 1 includes an input member attached to an input shaft to which rotational power is input from a driving force source, an output member that transmits the rotational power input from the input member to an output shaft, a planetary cone formed in a truncated cone shape having a conical surface where the input member and the output member come into contact, and a support shaft that supports the planetary cone rotatably and movably in the axial direction. This continuously variable transmission changes the speed of the rotational power of the input shaft to the output shaft through the planetary cone steplessly by changing 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. In addition, the planetary cone is provided with a plurality of ball cam mechanisms in which spheres are arranged in cam grooves. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-054008 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional continuously variable transmissions, if the clearance between the ball and the cam groove differs for each ball cam mechanism due to manufacturing errors, the load acting on the ball differs for each ball cam mechanism, reducing the durability and reliability of the continuously variable transmission, leaving room for further improvement. Also, reducing manufacturing errors reduces productivity, which needs to be avoided.

[0005] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide a continuously variable transmission that can improve productivity, durability, and reliability. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention provides a continuously variable transmission comprising: a sun roller provided on an input shaft to which rotational power is input from a drive force source; a ring roller for transmitting the input rotational power to an output shaft; a planetary cone having a conical surface that contacts the sun roller or the ring roller and formed in a truncated cone shape; a support shaft for rotatably supporting the planetary cone; and a movement mechanism for changing the contact position of the sun roller on the conical surface of the planetary cone and the contact position of the ring roller on the conical surface of the planetary cone so as to continuously change the speed of the rotational power of the input shaft to the output shaft via the planetary cone, wherein the planetary cones are an input side planetary cone with which the sun roller comes into contact, an output side planetary cone provided separately from the input side planetary cone and with which the ring roller comes into contact, and a front and a ball cam mechanism that connects a bottom surface of the input side planetary cone and a bottom surface of the output side planetary cone to transmit power from the input side planetary cone to the output side planetary cone, wherein the ball cam mechanism includes an input side cam groove formed in the bottom surface of the input side planetary cone, an output side cam groove formed in the bottom surface of the output side planetary cone, a sphere accommodated between the input side cam groove and the output side cam groove, and a retainer disposed between the input side cam groove and the output side cam groove and holding the sphere, wherein the input side cam groove and the output side cam groove extend in a circumferential direction and a radial direction about an axis of the support shaft, and are formed shallower toward the circumferential ends and toward the radial outside, and the retainer holds the sphere so as to be movable in the radial direction of the planetary cone. Effect of the Invention

[0007] Thus, according to the present invention, a continuously variable transmission that can improve productivity, durability, and reliability can be provided. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view of a rotational center axis of an input shaft and an axis of a support shaft at high speed in a continuously variable transmission according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of the central axis of rotation of the input shaft and the axis of the connecting member at high speed in a continuously variable transmission according to one embodiment of the present invention. [Diagram 3] FIG. 3 is a cross-sectional view of the rotational center axis of the input shaft and the axis of the support shaft at low speed in a continuously variable transmission according to one embodiment of the present invention. [Figure 4] FIG. 4 is a plan view of a cage provided on a planetary cone of a continuously variable transmission according to one embodiment of the present invention. [Diagram 5] 5 is a cross-sectional view of the cage shown in FIG. 4 taken along the arrows VV. [Figure 6] 6 is a cross-sectional view taken along the line VI-VI of the cage shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A continuously variable transmission according to one embodiment of the present invention is a continuously variable transmission including a sun roller provided on an input shaft to which rotational power is input from a drive source, a ring roller for transmitting the input rotational power to an output shaft, a planetary cone having a conical surface that contacts the sun roller or the ring roller and formed in a truncated cone shape, a support shaft for rotatably supporting the planetary cone, and a movement mechanism for changing the contact position of the sun roller on the conical surface of the planetary cone and the contact position of the ring roller on the conical surface of the planetary cone so as to continuously change the speed of the rotational power of the input shaft to the output shaft via the planetary cone, the planetary cone being an input side planetary cone with which the sun roller comes into contact, and an output side planetary cone provided separately from the input side planetary cone with which the ring roller comes into contact. and a ball cam mechanism that connects a bottom surface of the input planetary cone and a bottom surface of the output planetary cone to transmit power from the input planetary cone to the output planetary cone, the ball cam mechanism having an input cam groove formed on the bottom surface of the input planetary cone, an output cam groove formed on the bottom surface of the output planetary cone, a sphere accommodated between the input cam groove and the output cam groove, and a retainer disposed between the input cam groove and the output cam groove and holding the sphere, the input cam groove and the output cam groove extending in a circumferential direction and a radial direction about an axis of the support shaft, the circumferential end portions being shallower and the radially outwardly shallower, and the retainer holds the sphere movable in a radial direction of the planetary cone. As a result, the continuously variable transmission according to one embodiment of the present invention can improve productivity, durability, and reliability. EXAMPLES

[0010] Hereinafter, a continuously variable transmission according to an embodiment of the present invention will be described with reference to the drawings.

[0011] 1 to 6 are diagrams showing a continuously variable transmission according to an embodiment of the present invention. The directions (up, down, left, right) used in the description are directions used for convenience of the description. The cross-sectional views of FIGS. 1 to 3 are cross-sectional views taken along the axis of the input shaft of a continuously variable transmission according to an embodiment of the present invention, and are cross-sectional views showing only the upper side because they are symmetrical above and below the axis of the input shaft, and the up and down directions used in the description follow these drawings. In other words, the up direction in FIGS. 1 and 3 and the up direction in FIG. 2 are strictly different directions. Note that the up and down arrangement relationship is reversed for the lower side, which is not shown. In other words, based on the rotational axis of the input shaft, the direction radially away from the rotational axis of the input shaft is described as the up direction, and conversely, the direction approaching the rotational axis of the input shaft is described as the down direction. The left and right directions also follow the drawings. In other words, the side where the input shaft 2 to which the driving force source is connected is located is the left side, and this direction is also called the input side, input shaft side, and other end side. Conversely, the side on which the output shaft 3 to which the drive wheels are connected is located is referred to as the right side, and this direction is also referred to as the output side, output shaft side, or one end side.

[0012] First, the overall configuration will be described. As shown in Fig. 1, the continuously variable transmission 1 is mounted on a vehicle (not shown), and continuously changes the speed of the rotational power of a driving power source 10 such as an internal combustion engine or a motor (not shown) and transmits it to driving wheels (not shown).

[0013] The continuously variable transmission 1 includes a transmission case 41, an input shaft 2 to which rotational power is input from a driving power source 10, a sun roller 7 attached to the input shaft 2, and a ring roller 6 that transmits the rotational power input to the input shaft 2 to an output shaft 3 attached thereto.

[0014] The continuously variable transmission 1 includes a plurality of planetary cones 5 provided between a sun roller 7 and a ring roller 6. Each planetary cone 5 includes an input side planetary cone 14 having a conical surface 14d in contact with the sun roller 7, and an output side planetary cone 15 having a conical surface 15d in contact with the ring roller 6, and each of the input side planetary cone 14 and the output side planetary cone 15 is formed in a truncated cone shape.

[0015] The continuously variable transmission 1 includes a support shaft 16 that supports the planetary cone 5 rotatably and axially movable, and a main carrier 4 and an inner carrier 34 that rotatably hold the support shaft 16. An outer circumferential portion 4B of the main carrier 4 rotatably holds a left end portion 16A of the support shaft 16 via a bearing 17. The inner carrier 34 rotatably holds a right end portion 16B of the support shaft 16 via a bearing 54. The right end of each shaft in this embodiment corresponds to one end in the present invention, and the left end of each shaft in this embodiment corresponds to the other end in the present invention.

[0016] The continuously variable transmission 1 includes a movement mechanism 30, which moves the planetary cone 5 along the axial direction of the input shaft 2. This movement enables the continuously variable transmission 1 to change the gear ratio steplessly. The movement mechanism 30 changes the contact position P1 of the sun roller 7 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 moving the planetary cone 5, thereby steplessly changing the ratio of the rotational speed of the ring roller 6 to the rotational speed of the sun roller 7, and outputs the rotational power of the input shaft 2 to the output shaft 3 through the planetary cone 5.

[0017] The transmission case 41 is made up of a left case 42 and a right case 43 connected to the right end of the left case 42 by a bolt 41A. Inside the transmission case 41, various components (described later) that make up the continuously variable transmission 1 and oil are accommodated. This oil is traction oil that transmits power via an oil film at contact positions P1 and P2 and lubricates and cools various parts of the continuously variable transmission 1.

[0018] The continuously variable transmission 1 is equipped with an oil pump (not shown) that circulates oil. The oil pump draws oil stored inside the transmission case 41 and pumps it to the axial hole 2H of the input shaft 2. The oil pumped to the axial hole 2H of the input shaft 2 lubricates the parts that require lubrication, and then is stored inside the transmission case 41, and is pumped again to the axial hole 2H of the input shaft 2 by the oil pump.

[0019] The input shaft 2 and the output shaft 3 will now be described. The input shaft 2 extends in the left-right direction, and a driving force source 10 is connected to the left end of the input shaft 2. An axis 2r along the input shaft 2 is the central axis of rotation of the input shaft 2, and the input shaft 2 rotates around the axis 2r. The direction of the axis 2r is referred to as the axial direction. The output shaft 3 is disposed on the right end side of the input shaft 2, coaxial with the axis 2r of the input shaft 2. In other words, the central axis of rotation of the output shaft 3 is a common axis with the axis 2r which is the central axis of rotation of the input shaft 2.

[0020] The input shaft 2 has a cylindrical portion 2A formed in a cylindrical shape along the axis 2r at the right end, and a small diameter portion 2B formed on the left end side with a smaller diameter than the cylindrical portion 2A. The cylindrical portion 2A opens to the right, and the left end portion 3A of the output shaft 3 is inserted into the cylindrical portion 2A. The inner peripheral surface of the cylindrical portion 2A supports the left end portion 3A of the output shaft 3 via a bearing 51 made of a ball bearing. The cylindrical portion 2A is inserted into a hole in the inner peripheral portion 34A of the inner carrier 34. The outer peripheral surface of the cylindrical portion 2A supports the inner peripheral portion 34A of the inner carrier 34 via a bearing 63 made of a needle bearing.

[0021] The cylindrical portion 2A is the portion of the input shaft 2 with the largest diameter, and the input shaft 2 is formed so that its diameter decreases from the right end to the left end.

[0022] A step portion 2C is formed on the left end face of the cylindrical portion 2A. The step portion 2C forms a surface perpendicular to the axis 2r of the input shaft 2.

[0023] The step portion 2C abuts against a side surface of the right end of the sun roller 7 in the axial direction to position the sun roller 7 in the axial direction.

[0024] A sun roller 7 is fixed to the outer periphery of the right end side of the small diameter portion 2B, in the vicinity of the left side of the stepped portion 2C. The sun roller 7 has a disk shape coaxial with the input shaft 2, and the input shaft 2 is spline-fitted into a through hole formed in the center of the sun roller 7. The sun roller 7 is formed with a larger diameter than the cylindrical portion 2A. In other words, the sun roller 7 is formed with a large diameter so as to protrude radially outward from the input shaft 2.

[0025] The sun roller 7 has an inner peripheral edge 7A fixed to the input shaft 2, and an outer peripheral edge 7B disposed axially offset toward the right end side from the inner peripheral edge 7A so as to surround the left end of the inner carrier 34 and the left end of the cylindrical portion 2A from the outer periphery side. In other words, the sun roller 7 is not formed in a flat disk shape, but in a shape in which the outer peripheral edge 7B is shifted to the right from the inner peripheral edge 7A. The outer peripheral edge 7B of the sun roller 7 and the left end of the inner carrier 34 are disposed at the same position as the cylindrical portion 2A in the axial direction of the input shaft 2. That is, as shown in FIG. 1, the outer peripheral edge 7B of the sun roller 7 is disposed so that the left end of the inner carrier 34 fits into the inner diameter side. Furthermore, the left end of the bearing 63 and the left end of the bearing 53 are disposed so that they fit into the inner diameter side of the outer peripheral edge 7B of the sun roller 7.

[0026] The sun roller 7 has an inner peripheral edge 7A extended toward the left end in the axial direction so as to axially extend the through hole into which the input shaft 2 is inserted. A bearing 62 that supports the input shaft 2 is disposed on the left end of the sun roller 7 in the axial direction, and the right end of the inner ring of this bearing 62 abuts against the left end of the inner peripheral edge 7A of the sun roller 7. The sun roller 7 is positioned by being sandwiched in the axial direction between the stepped portion 2C and the bearing 62. The posture of the sun roller 7 is stabilized by the axial sandwiching between the stepped portion 2C and the bearing 62 and the extended inner peripheral edge 7A.

[0027] A first oil passage 2D is formed in the cylindrical portion 2A, penetrating from the inner periphery side to the outer periphery side. The first oil passage 2D is formed near the left end of the cylindrical portion 2A, and the outer periphery edge portion 7B of the sun roller 7, which is shifted to the right, is arranged at the same position as the first oil passage 2D in the axial direction of the input shaft 2. Furthermore, as shown in FIG. 1, the first oil passage 2D is formed on the left side of the inner diameter hole of the cylindrical portion 2A into which the left end portion 3A of the output shaft 3 is inserted. A second oil passage 2E is formed in the cylindrical portion 2A, penetrating from the inner periphery side to the outer periphery side, on the right end side (output shaft 3 side) of the first oil passage 2D in the axial direction. The second oil passage 2E is formed in the inner diameter hole portion of the cylindrical portion 2A into which the left end portion 3A of the output shaft 3 is inserted, and is arranged within the movement range of the inner carrier 34 in the axial direction of the input shaft 2. The first oil passage 2D and the second oil passage 2E are arranged within the range of the ring roller 6 and the output shaft 3 in the axial direction.

[0028] The first oil passage 2D opens into the range in the axial direction of the input shaft 2 where the sun roller 7 is disposed and into the range in which the ring roller 6 is disposed. The first oil passage 2D supplies oil to a contact position P1 between the sun roller 7 and the input side planetary cone 14. The first oil passage 2D supplies oil to a contact position P2 between the ring roller 6 and the output side planetary cone 15. The first oil passage 2D supplies oil to a bearing 63 between the input shaft 2 and the inner carrier 34 and a bearing 54 between the support shaft 16 and the inner carrier 34 in a speed change state for high speed driving (at high speed). Note that at high speed, the rotation speed of the output shaft 3 at a predetermined rotation speed of the input shaft 2 is faster than in other speed change states.

[0029] The second oil passage 2E opens into the range in which the inner carrier 34 is disposed and the range in which the ring roller 6 is disposed at an axial position of the input shaft 2. The second oil passage 2E supplies oil to a contact position P2 between the ring roller 6 and the output-side planetary cone 15. The second oil passage 2E always supplies oil to the bearing 54 between the support shaft 16 and the inner carrier 34 and the bearing 63 between the input shaft 2 and the inner carrier 34, regardless of whether the speed change state is for high-speed driving or low-speed driving.

[0030] The lubrication of the bearings 17 between the support shaft 16 and the main carrier 4 will be described. Some of the bearings 17, of which there are several for each planetary cone 5, are located high up in the transmission case 41, but they are located at about the same position as the ring roller 6 with respect to the input shaft 2 and are located near the inner wall of the internal space of the continuously variable transmission 1. Therefore, oil supplied from the first oil passage 2D or the second oil passage 2E to the inner surface of the ring roller 6 and leaking from the inner surface of the ring roller 6 through the contact position P2 of the ring roller 6 with the output side planetary cone 15 due to centrifugal force, and oil carried around the inner surface of the transmission case 41 by the rotation of the ring roller 6 are supplied.

[0031] Of the transmission case 41, the right case 43 located on the ring roller 6 side and the left case 42 located on the bearing 17 side are configured so that the inner diameter of the left case 42 on the bearing 17 side is larger, and the oil flowing inside the transmission case 41 flows into the bearing 17 side.

[0032] The lubrication of the bearing 51 between the input shaft 2 and the output shaft 3 will be described. Oil is supplied from the axis of the input shaft 2 to the bearing 51 between the input shaft 2 and the output shaft 3. The bearing 51 is disposed on the right side of the first oil passage 2D and the second oil passage 2E and in the vicinity of the right end of the cylindrical portion 2A.

[0033] Therefore, the bearing 51 is disposed downstream of the flow of oil inside the input shaft 2, and generates flow resistance that further restricts the flow of oil to the right. This makes it possible to increase the amount of oil discharged from inside the input shaft 2 through the first oil passage 2D and the second oil passage 2E. The oil that has passed through the bearing 51 flows into the output drum 8 from an opening at the right end of the cylindrical portion 2A, and flows into the recess 6B on the inner circumferential surface of the ring roller 6.

[0034] Oil is also supplied to the bearings 61 and 62 between the handle shaft 31B and the input shaft 2. The oil discharged from the shaft end of the handle shaft 31B collides with the side of the sun roller 7 and scatters around. Since the outer edge of the opposing surface (bottom surfaces 14b, 15b) between the input side planetary cone 14 and the output side planetary cone 15 is located near the inner diameter of the ring roller 6, the oil present in the recess 6B on the inner peripheral surface of the ring roller 6 enters and is supplied to the ball cam mechanism 21 of the planetary cone 5. Note that even in other shifting states, the outer edge of the opposing surface (bottom surfaces 14b, 15b) between the input side planetary cone 14 and the output side planetary cone 15 is positioned so as to face the recess 6B on the inner peripheral surface of the ring roller 6, so that the oil present in the recess 6B is efficiently supplied to the ball cam mechanism 21.

[0035] A ring-shaped expanded diameter portion 3B that protrudes in the radial direction is formed in the longitudinal center of the output shaft 3, and a cylindrical output drum 8 is fixed to the outer periphery of this expanded diameter portion 3B by welding or the like. The output drum 8 is disposed coaxially with the input shaft 2, and is formed into a shape that fits along the inner circumferential surface of the light case 43.

[0036] The inner diameter portion of the output drum 8 is located to the right of the outer diameter portion, and is fixed to the expanded diameter portion 3B of the output shaft 3. The outer diameter portion of the output drum 8 is located to the left of the inner diameter portion, and a cylindrical ring roller 6 is attached by a bolt 6A.

[0037] In this embodiment, the output shaft 3 and the output drum 8 are manufactured separately and then joined together to form a joined structure. This improves the workability of the manufacturing process of the output shaft 3 and the output drum 8, and improves the productivity of the output shaft 3 and the output drum 8.

[0038] The center portion of the output shaft 3 is rotatably supported by the light case 43 via a bearing 50 made of a ball bearing.

[0039] A flange 55 is attached to the right end of the output shaft 3 by spline fitting. The flange 55 is connected to a differential device (not shown). The differential device is connected to left and right drive wheels via left and right drive shafts (not shown). The differential device distributes the rotational power of the driving 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.

[0040] A cylindrical bearing holding member 46 is fixed to the right end of the light case 43 by a bolt 46A. A bearing 52 made of a ball bearing is provided between the inner peripheral surface of the bearing holding member 46 and the outer peripheral surface of the cylindrical left end of the flange 55. The flange 55 and the right end of the output shaft 3 spline-fitted to the flange 55 are rotatably supported by the light case 43 via the bearing 52.

[0041] The planetary cone 5 will now be described. The planetary cone 5 has an input side planetary cone 14 having a truncated cone shape with which the sun roller 7 comes into contact, and an output side planetary cone 15 having a truncated cone shape that is provided separately from the input side planetary cone 14 and with which the ring roller 6 comes into contact.

[0042] 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 their bottom surfaces 14b, 15b facing each other. In other words, 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 their bottom surfaces face each other.

[0043] The input side planetary cone 14 and the output side planetary cone 15 are supported by the support shaft 16 so that they can move on the support shaft 16 in the direction of the axis 16r within the range between a bearing 17 at the left end of the support shaft 16 and a bearing 54 at the right end of the support shaft 16.

[0044] In the assembled state, the input side planetary cone 14 abuts against the sun roller 7, thereby regulating the position of the output shaft 3 side (right end side) of the support shaft 16, and the output side planetary cone 15 abuts against the ring roller 6, thereby regulating the position of the input shaft 2 side (left end side) of the support shaft 16.

[0045] The planetary cone 5 rotates (spins) around the support shaft 16 but does not rotate (revolves) around the input shaft 2.

[0046] The support shaft 16 is installed in an inclined position with respect to the axis 2r of the input shaft 2 so that its axis 16r is inclined relative to the axis 2r of the input shaft 2. Specifically, the axis 16r of the support shaft 16 is installed inclined with respect to the axis 2r of the input shaft 2 so that its central axis approaches the input shaft 2 as it moves to the right.

[0047] As the main carrier 4 and inner carrier 34, which hold the support shaft 16, move in the direction of the axis 2r of the input shaft 2 by the moving mechanism 30, the planetary cone 5 moves in the direction of the axis 2r of the input shaft 2 together with the main carrier 4 and inner carrier 34.

[0048] A plurality of planetary cones 5 are provided at equal intervals in the circumferential direction so as to surround the input shaft 2 radially outward of the input shaft 2. More specifically, six planetary cones 5 are provided at 30 degree intervals in the circumferential direction. This allows the normal forces acting from each planetary cone 5 on the sun roller 7 and ring roller 6 to cancel each other out. Moreover, in the continuously variable transmission 1 according to one embodiment of the present invention, an even number of planetary cones 5 are provided.

[0049] The sun roller 7 is in contact with the conical surface 14 d of the input side planetary cone 14 , and the ring roller 6 is in contact with the conical surface 15 d of the output side planetary cone 15 .

[0050] The input side planetary cone 14 is disposed in such a position that the generatrix of its conical surface 14d on the side where the input shaft 2 is disposed extends parallel to the axis 2r of the input shaft 2 to form a conical surface that is constantly in contact with the sun roller 7. In other words, the input side planetary cone 14 is disposed in such a position that the generatrix that passes through the contact position P1 with the sun roller 7 on the conical surface 14d extends parallel to the axis 2r of the input shaft 2.

[0051] The output side planetary cone 15 is installed in a position such that a generatrix on the conical surface 15d opposite the input shaft 2 extends parallel to the axis 2r of the input shaft 2 to form a conical surface that is constantly in contact with the ring roller 6. In other words, the output side planetary cone 15 is disposed in a position such that a generatrix passing through the contact position P2 with the ring roller 6 on the conical surface 15d extends parallel to the axis 2r of the input shaft 2.

[0052] In other words, 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 an attitude such that the conical surface that is always in contact with the sun roller 7 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, so that contact between the conical surface 14d and the sun roller 7 is maintained, and contact between the conical surface 15d and the ring roller 6 is maintained.

[0053] The left end 16A of the support shaft 16 is enlarged in diameter to prevent the output side planetary cone 15 from coming off. In other words, the left end 16A of the support shaft 16 is formed to have a larger diameter than the inner diameter of the hole formed in the output side planetary cone 15 through which the support shaft 16 is inserted. The right end 16B of the support shaft 16, except for the left end 16A, is reduced in diameter so that the output side planetary cone 15, the sphere 20, the retainer 22, the spring 5A, and the input side planetary cone 14 can pass through. A sleeve 35 is fixed to the right end 16B of the support shaft 16 by press fitting. The sleeve 35 has the same diameter as the left end of the support shaft 16, and prevents each member assembled to the support shaft 16 from coming off.

[0054] That is, the planetary cone 5 is assembled so that the output side planetary cone 15, the sphere 20, the retainer 22, the spring 5A, the input side planetary cone 14, and the sleeve 35 are attached to the support shaft 16 from the left end 16A side of the support shaft 16 to form an assembly. In this assembled state, the planetary cone 5 can move in the axial direction between the enlarged diameter portion of the left end 16A of the support shaft 16 and the sleeve 35, but the output side planetary cone 15 and the input side planetary cone 14 are biased in the direction away from each other by the spring 5A, so that the output side planetary cone 15 abuts against the enlarged diameter portion and the input side planetary cone 14 abuts against the sleeve 35, and therefore the position of the planetary cone 5 is stably maintained. In addition, the spring 5A and the retainer 22 prevent the sphere 20 from falling off. In this assembled state, a bearing 54 is attached to the sleeve 35, and an outer ring of the bearing 54 is fitted into a retaining hole of the inner carrier 34, so that the right end 16B of the support shaft 16 is supported by the inner carrier 34. Then, the left end 16A of the support shaft 16 is disposed inside a retaining hole formed in the outer periphery 4B of the main carrier 4, and a bearing 17 is fitted between the left end 16A of the support shaft 16 and the main carrier 4, so that the left end 16A of the support shaft 16 is supported by the outer periphery 4B of the main carrier 4. As shown in FIG. 1, the bearing 17 is prevented from slipping out of the retaining hole formed in the outer periphery 4B of the main carrier 4 by a circlip.

[0055] The ball cam mechanism 21 will be described. The planetary cone 5 has the 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 so as to be capable of transmitting power, and transmits power between the input side planetary cone 14 and the output side planetary cone 15.

[0056] The ball cam mechanism 21 has a plurality of input cam grooves 14f formed on the bottom surface 14b of the input planetary cone 14, a plurality of output cam grooves 15f formed on the bottom surface 15b of the output planetary cone 15, and a sphere 20 accommodated so as to straddle the input cam grooves 14f and the output cam grooves 15f. The input cam grooves 14f and the output cam grooves 15f are formed in equal numbers and extend in the circumferential direction centered on the axis 16r of the support shaft 16. The input cam grooves 14f and the output cam grooves 15f are formed at positions that face each other when the bottom surface 14b and the bottom surface 15b are arranged opposite each other, and are arranged at equal angular positions on the circumference centered on the axis 16r.

[0057] When a large torque is input to the continuously variable transmission 1, a repulsive force is generated by the spheres 20 in the ball cam mechanism 21, causing the input side planetary cone 14 and the output side planetary cone 15 to move away from each other, thereby increasing the contact pressure at contact position P1 between the input side planetary cone 14 and the sun roller 7, and the contact pressure at contact position P2 between the output side planetary cone 15 and the ring roller 6.

[0058] In addition, when a large torque is input, the ball cam mechanism 21 connects the input side planetary cone 14 and the output side planetary cone 15 so that they can rotate together by determining the position of the sphere 20 in the input side cam groove 14f and the output side cam groove 15f based on the balance between the repulsive force and the contact surface pressure.

[0059] The input side cam groove 14f and the output side cam groove 15f are each formed so that their depths change in the circumferential direction. Specifically, the input side cam groove 14f and the output side cam groove 15f are formed so that they are deep in the circumferential center and gradually become shallower as they approach both ends in the circumferential direction. In other words, the input side cam groove 14f and the output side cam groove 15f are formed so that they are shallower toward the ends in the circumferential direction.

[0060] Furthermore, the input-side cam groove 14f and the output-side cam groove 15f have a cross-sectional shape along the axis 16r of the support shaft 16 and in the radial direction, which is an arc shape with a radius slightly larger than the radius of the sphere 20. Therefore, the sphere 20 disposed in the space between the input-side cam groove 14f and the output-side cam groove 15f, each of which is formed so that the depth varies in the radial direction, can move in the radial direction until it abuts against the input-side cam groove 14f and the output-side cam groove 15f. Specifically, the input-side cam groove 14f and the output-side cam groove 15f are formed so that they become gradually shallower as they approach the outer end in the radial direction. In other words, the input-side cam groove 14f and the output-side cam groove 15f are formed so that they become shallower toward the outer side in the radial direction.

[0061] In this way, the input side cam groove 14f and the output side cam groove 15f extend in the circumferential and radial directions around the axis of the support shaft 16, and are formed so that they are shallower toward the circumferential ends and shallower toward the radial outward direction.

[0062] The ball 20 is free to roll in the circumferential direction along the input-side cam groove 14f and the output-side cam groove 15f, and the input-side cam groove 14f and the output-side cam groove 15f are set so that the groove width dimension in the radial direction centered on the axis 16r of the support shaft 16 is approximately the same as the dimension of the ball 20 abutting against the groove bottom at that position (the cross-sectional dimension when cut at the bottom surfaces 14b, 15b of the planet cone 5). For this reason, the groove width of the input-side cam groove 14f and the output-side cam groove 15f is formed in a shape that is wide in the circumferential center and gradually narrows from the circumferential center to both ends in the circumferential direction.

[0063] The input side cam groove 14f and the output side cam groove 15f are formed at positions that face each other when the bottom surface 14b and the bottom surface 15b are joined together, and have the same shape. The input side planetary cone 14 and the output side planetary cone 15 are also formed in the same shape. In other words, the input side planetary cone 14 and the output side planetary cone 15 have the same shape and are interchangeable, improving productivity.

[0064] In other words, even if the input side planetary cone 14 is swapped for the position of the output side planetary cone 15 and the output side planetary cone 15 is swapped for the position of the input side planetary cone 14, the planetary cone 5 can have the same shape.

[0065] The input planetary cone 14 transmits power to the output planetary cone 15 via a sphere 20. The sphere 20 is made of, for example, a steel ball, but is not limited to a steel ball.

[0066] In this embodiment, the dimensional tolerances are set so that a gap is provided 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 7 when the input side planetary cone 14 and the output side planetary cone 15 are closest to each other, and the dimensional tolerances are set so that a gap is provided 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 when the input side planetary cone 14 and the output side planetary cone 15 are closest to each other. In other words, the dimensions of each part are set so that the contact positions P1 and P2 are not press-fitted when the spring 5A is compressed to bring the input side planetary cone 14 and the output side planetary cone 15 to the closest position during the assembly work of the planetary cone 5. This makes it easy to assemble the planetary cone 5 to the continuously variable transmission 1.

[0067] In the planetary cone 5, when power is input from the sun roller 7 to the input side planetary cone 14, the input side planetary cone 14 and the output side planetary cone 15 temporarily rotate relative to each other so that their rotational positions are shifted due to the difference between the torque that can be transmitted by contact between the sphere 20 and the input side cam groove 14f and the torque that can be transmitted by contact between the sphere 20 and the output side cam groove 15f.

[0068] In other words, when power is input from the sun roller 7 to the input side planetary cone 14, a state occurs in which the rotation of the output side planetary cone 15 temporarily lags behind the rotation of the input side planetary cone 14 due to contact of the output side planetary cone 15 with the ring roller 6 or inertia due to the output side planetary cone 15's own weight.

[0069] As a result, the relative positions of the input side planetary cone 14 and the output side planetary cone 15 in the rotational direction are shifted, and the ball 20 moves (rolls) inside the input side cam groove 14f and the output side cam groove 15f. When the ball 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 ball 20 separates the input side planetary cone 14 and the output side planetary cone 15 in the axial direction of the support shaft 16.

[0070] In other words, when the sphere 20 moves, the positions of the input side cam groove 14f and output side cam groove 15f with which the sphere 20 abuts change, and the sphere 20 is displaced to a location of a different depth. As a result, the amount by which the sphere 20 protrudes from the input side cam groove 14f and output side cam groove 15f changes, causing the input side planetary cone 14 and the output side planetary cone 15 to move closer or farther apart in the axial direction of the support shaft 16.

[0071] In other words, when the depth of the input side cam groove 14f and output side cam groove 15f in which the sphere 20 is located becomes 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 of the input side planetary cone 14 and the output side planetary cone 15 in the rotational direction subsides due to the reaction force from the sun roller 7 and the ring roller 6, they rotate together via the sphere 20.

[0072] This situation occurs when the torque to be transmitted increases, 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, resulting in stronger contact between the input side planetary cone 14 and the sun roller 7, and between the output side planetary cone 15 and the ring roller 6, making it possible to transmit a larger torque.

[0073] On the other hand, when the depth of the input side cam groove 14f and the output side cam groove 15f in which the sphere 20 is located becomes deeper, the input side planetary cone 14 and the output side planetary cone 15 approach the axial direction of the support shaft 16, and when the relative movement between the input side planetary cone 14 and the output side planetary cone 15 in the rotational direction subsides, they rotate together via the sphere 20.

[0074] This situation occurs when the transmitted torque decreases, and the input side planetary cone 14 and the output side planetary cone 15 approach each other in the axial direction of the support shaft 16, weakening the force pressing the input side planetary cone 14 against the sun roller 7 and the force pressing the output side planetary cone 15 against the ring roller 6. This eliminates unnecessary pressing forces for torque transmission and improves durability.

[0075] The input side planetary cone 14 and the output side planetary cone 15 are connected via a ball cam mechanism 21 and rotate integrally about the axis 16r of the support shaft 16, except for relative movement (deviation) due to a torque difference.

[0076] Even when the input side planetary cone 14 and the output side planetary cone 15 are at their farthest position in the axial direction of the support shaft 16, the spheres 20 do not come out of the input side cam groove 14f and the output side cam groove 15f. In other words, when assembled to the continuously variable transmission 1, the input side planetary cone 14 and the output side planetary cone 15 can be spaced apart in the axial direction of the support shaft 16 within a distance smaller than the diameter of the spheres 20.

[0077] In addition, both circumferential ends of the input side cam groove 14f and the output side cam groove 15f abut against the sphere 20 and function as stoppers to restrict further deviation (relative rotation angle) between the input side planetary cone 14 and the output side planetary cone 15.

[0078] The cage 22 will be described. As shown in FIG. 1, FIG. 5, and FIG. 6, the continuously variable transmission 1 has a disk-shaped cage 22 disposed between the input side planetary cone 14 and the output side planetary cone 15, and the cage 22 holds the sphere 20. The cage 22 is made of a member thinner than the diameter of the sphere 20. In detail, a circular recess formed larger than the diameter of the cage 22 and accommodating the cage 22 is formed on the opposing surfaces (bottom surfaces 14b, 15b) of the input side planetary cone 14 and the output side planetary cone 15. The outer edge portions of the bottom surfaces 14b, 15b, which are larger in diameter than the recess, approach each other and surround the periphery of the cage 22, enlarging the conical surface 14d and the conical surface 15d. The input side cam groove 14f and the output side cam groove 15f are formed at the bottom of the circular recess.

[0079] As shown in Fig. 5, the retainer 22 holds the spheres 20 so as to be movable radially outward from the planetary cone 5. Also, as shown in Figs. 4 and 6, the retainer 22 holds the spheres 20 so as to restrict movement in the circumferential direction of the planetary cone 5. In other words, the retainer 22 holds the spheres 20 so as to allow movement in the radial direction of the retainer 22 but not to allow movement in the circumferential direction of the retainer 22. The retainer 22 restricts the positions of the spheres 20 so that the spheres 20 are evenly spaced on the circumference.

[0080] As shown in FIG. 4, in order to hold the sphere 20 so as to be movable in the radial direction but not in the circumferential direction, the cage 22 has a notch 22A that holds the sphere 20 therein and regulates the position of the sphere 20. More specifically, the notch 22A is formed in a U-shape with an open radial outer diameter side, and is formed so that the radial length relative to the axis of the support shaft 16 is longer than the circumferential length. The notch 22A is formed in a substantially semicircular shape with an open radial outer diameter side and a radial inner diameter side that matches the cross-sectional shape of the sphere 20. Due to this shape, the notch 22A allows the sphere 20 to move in the radial direction of the planetary cone 5 and regulates the movement of the sphere 20 in the circumferential direction of the planetary cone 5.

[0081] 5 and 6, the edge 22B of the cutout 22A facing the input planetary cone 14 is narrowed so that the sphere 20 cannot pass through. More specifically, the width of the edge 22B on the side where the spring 5A is arranged in the cutout 22A (the side of the input planetary cone 14 that is later attached to the support shaft 16) is narrowed so that the sphere 20 cannot pass through. As a result, the retainer 22 pressed against the output planetary cone 15 by the spring 5A can hold the sphere 20 in the cutout 22A with the output planetary cone 15.

[0082] The spring 5A will be described. As shown in FIG. 1 and FIG. 5, the ball cam mechanism 21 includes the spring 5A as an elastic member. The spring 5A is provided in a compressed state around the support shaft 16 between the bottom surface 14b of the input side planetary cone 14 and the bottom surface 15b of the output side planetary cone 15. A hole with a larger diameter than the support shaft 16 is formed in the center of the recess formed in the bottom surfaces 14b, 15b of the input side planetary cone 14 and the output side planetary cone 15, and one end of the spring 5A is arranged to enter this hole, and the other end of the spring 5A is arranged to enter a hole with a larger diameter than the support shaft 16 formed in the center part of the retainer 22. In other words, one end of the spring 5A is arranged between the inner surface of the large diameter hole in the center part of the recess and the support shaft 16, and the other end of the spring 5A is arranged between the inner surface of the large diameter hole in the center part of the retainer 22 and the support shaft 16. More specifically, the spring 5A is provided between the bottom surface 14b of the input planetary cone 14 and the retainer 22. The spring 5A urges the retainer 22 toward the output planetary cone 15 by a restoring force (urging force). In other words, the spring 5A is disposed between the input planetary cone 14, which is attached to the support shaft 16 later, and the retainer 22, and is urged toward the output planetary cone 15, which is assembled to the support shaft 16 earlier. The restoring force of the spring 5A acts in a direction that separates the input planetary cone 14 and the output planetary cone 15.

[0083] The restoring force of the spring 5A pushes the input side planetary cone 14 and the output side planetary cone 15 in directions away from each other even when the planetary cone 5 is not transmitting torque, so that the input side planetary cone 14 is pressed against the sun roller 7 and the output side planetary cone 15 is pressed against the ring roller 6. As a result, the conical surface 14d of the input side planetary cone 14 is in constant contact with the sun roller 7, and the conical surface 15d of the output side planetary cone 15 is in constant contact with the ring roller 6.

[0084] As a result, the input side planetary cone 14 can be prevented from rotating freely relative to the sun roller 7, and the output side planetary cone 15 can be prevented from rotating freely relative to the ring roller 6, so that the planetary cone 5 can transmit torque without slipping.

[0085] In other words, when power is input from the sun roller 7 to the input side planetary cone 14, a rotational force can be transmitted from the output side planetary cone 15 to the abutting ring roller 6. When a large torque is input, relative rotation between the input side planetary cone 14 and the output side planetary cone 15 can be immediately generated, and the repulsive force of the ball cam mechanism 21 can be used to increase the contact pressure at contact position P1 between the input side planetary cone 14 and the sun roller 7, and the contact pressure at contact position P2 between the output side planetary cone 15 and the ring roller 6. This makes it possible to increase the contact pressure at contact positions P1 and P2 only when necessary.

[0086] The main carrier 4 and the inner carrier 34 will be described. The main carrier 4 is an annular member that holds the left end of the support shaft 16, and the input shaft 2 is inserted through the center and disposed around the input shaft 2. The main carrier 4 holds the left ends of a plurality of support shafts 16 that support planetary cones 5 rotatably (on their own axes). In other words, the input shaft 2 is disposed so as to pass through the main carrier 4, and the plurality of planetary cones 5 are disposed so as to surround the input shaft 2. The main carrier 4 holds the support shafts 16 at its outer periphery 4B via bearings 17 made of ball bearings.

[0087] The inner carrier 34 is an annular member that holds the right end portion 16B of the support shaft 16, and is disposed around the input shaft 2 with the input shaft 2 inserted through its center. The inner carrier 34 holds the right end portions of the multiple support shafts 16 that support the planetary cones 5 to be rotatable (rotatable on their own axes). In other words, the input shaft 2 is disposed so as to pass through the inner carrier 34. The inner carrier 34 holds the support shafts 16 via bearings 54 made of ball bearings.

[0088] In this way, the planetary cone 5 is supported by the main carrier 4 and the inner carrier 34 via the support shaft 16. The main carrier 4 is disposed on the input shaft 2 side (left side) of the sun roller 7 with respect to the planetary cone 5 in the axial direction of the input shaft 2. The inner carrier 34 is disposed on the output shaft 3 side (right side) of the sun roller 7 with respect to the planetary cone 5 in the axial direction of the input shaft 2.

[0089] A bearing 63 made of a needle bearing is held on the inner periphery side of the inner carrier 34, and the bearing 63 rotatably supports the inner carrier 34 on the input shaft 2. In other words, the input shaft 2 is disposed penetrating the inner carrier 34, and the inner carrier 34 is supported by the input shaft 2 via the bearing 63 so as to be relatively rotatable.

[0090] The main carrier 4 and the inner carrier 34 are connected via a shift flange 32 and a connecting member 33 (see FIG. 2) described later, and are moved integrally by a movement mechanism 30.

[0091] 2, a guide shaft 44 extending rightward in parallel with the input shaft 2 is fixed to the left case 42, and this guide shaft 44 penetrates the main carrier 4. The main carrier 4 slides in the axial direction relative to the guide shaft 44, and a sleeve 44A is provided between the outer periphery of the guide shaft 44 and a hole formed in the main carrier 4 to reduce frictional resistance.

[0092] The guide shaft 44 restricts the rotation of the main carrier 4 around the input shaft 2. In other words, the guide shaft 44 restricts the main carrier 4 from rotating relative to the transmission case 41. The guide shaft 44 also allows and guides the movement of the input shaft 2 of the main carrier 4 in the axial direction. For this reason, the inner carrier 34 connected to the main carrier 4 is also restricted from rotating relative to the transmission case 41, and the movement of the input shaft 2 in the axial direction is permitted and guided.

[0093] The movement mechanism 30 will be described. The movement mechanism 30 includes a gear shift operating unit 31, which is rotated around the axis of the input shaft 2 from the outside by an actuator or the like. The gear shift operating unit 31 includes an operating unit 31A that is operated from the outside, and a handle shaft 31B fixed to the right end of the operating unit 31A. The operating unit 31A is exposed to the outside on the left side of the transmission case 41, and is formed in a cylindrical shape so as to surround the input shaft 2. The handle shaft 31B is disposed at the center of the main carrier 4 inside the transmission case 41, and surrounds the outer circumferential surface of the input shaft 2. A feed screw is formed on the outer circumferential surface of the handle shaft 31B.

[0094] The handle shaft 31B is rotatably supported by the left case 42 via a bearing 53. The handle shaft 31B passes through the center of the main carrier 4, and the input shaft 2 is disposed at the center of the handle shaft 31B. The handle shaft 31B supports the input shaft 2 via bearings 61 and 62.

[0095] The movement mechanism 30 includes a shift flange 32. The shift flange 32 is formed in an annular shape so as to surround the outer periphery of the handle shaft 31B of the gearshift operation part 31. A feed screw that screws into the feed screw of the handle shaft 31B of the gearshift operation part 31 is formed on the inner periphery of the shift flange 32.

[0096] An outer circumferential portion of the shift flange 32 is disposed to the right of an inner circumferential portion 4A of the main carrier 4. An outer circumferential portion of the shift flange 32 is connected to the inner circumferential portion 4A of the main carrier 4 by a bolt 45. The bolt 45 is inserted into the main carrier 4 from the left and screwed into the shift flange 32.

[0097] As shown in FIG. 2, the movement mechanism 30 includes a hollow cylindrical coupling member 33. The coupling member 33 extends in the axial direction of the input shaft 2, and the left end of the coupling member 33 is fitted into a hole formed in the outer periphery of the shift flange 32. The coupling member 33 is disposed between the planetary cones 5, and extends rightward from the shift flange 32, passing near the outer periphery of the sun roller 7. The right end of the coupling member 33 is fitted into a hole formed in the outer periphery 34B of the inner carrier 34. A bolt 33A that fastens and fixes the shift flange 32 and the inner carrier 34 is inserted inside the coupling member 33, and the coupling member 33 is sandwiched and fixed between the shift flange 32 and the inner carrier 34 by the bolt 33A. In this way, the main carrier 4 and the inner carrier 34 are connected and integrated via the shift flange 32 and the coupling member 33.

[0098] In the moving mechanism 30, when the gear shift operating unit 31 is rotated from the outside, the feed screw mechanism moves the shift flange 32 in the axial direction of the input shaft 2. Then, the main carrier 4 connected to the shift flange 32 with bolts 45, the inner carrier 34 connected to the shift flange 32 via a connecting member 33, and the planetary cone 5 held by the main carrier 4 and the inner carrier 34 move in the axial direction of the input shaft 2 together with the shift flange 32.

[0099] In this embodiment, the shift flange 32 is moved in the axial direction by the feed screw mechanism, but the shift flange 32 may be moved in the axial direction directly by an actuator without using the feed screw mechanism.

[0100] As shown in Fig. 1, a seal member 64 is provided between the inner peripheral surface of the left end of the handle shaft 31B of the gear shift operating unit 31 and the outer peripheral surface of the input shaft 2. A seal member 65 is provided between the outer peripheral surface of the left end of the handle shaft 31B of the gear shift operating unit 31 and the inner peripheral surface of the left end of the left case 42 of the transmission case 41. Furthermore, a seal member 66 is provided between the right vicinity of the bearing 50 on the outer periphery of the output shaft 3 and the inner peripheral surface of the right end of the right case 43 of the transmission case 41. These seal members 64, 65, 66 prevent oil from leaking from the inside of the transmission case 41 to the outside, and prevent foreign matter from entering the inside of the transmission case 41 from the outside.

[0101] A bearing 61 made of a ball bearing is provided between the inner circumferential surface near the left end of the handle shaft 31B of the gear shift operating unit 31 and the outer circumferential surface of the input shaft 2. A bearing 62 made of a ball bearing is provided between the inner circumferential surface near the right end of the handle shaft 31B of the gear shift operating unit 31 and the outer circumferential surface of the input shaft 2.

[0102] Bearing 53, which is a ball bearing, is provided on the outer circumferential surface near the left end of handle shaft 31B of gear shift operating part 31, to the right of seal member 65. The inner circumferential portion (inner ring) of bearing 53 is fitted onto handle shaft 31B. The outer circumferential portion (outer ring) of bearing 53 is fitted onto the inner circumferential surface of the left end of left case 42 of transmission case 41.

[0103] Thus, in this embodiment, the gear shift operating device 31 is rotatably supported with respect to the transmission case 41 by the bearing 53. In addition, a left end portion of the input shaft 2 is rotatably supported with respect to the gear shift operating device 31 by the bearings 61 and 62.

[0104] In the continuously variable transmission 1 of this embodiment, a contact position P1 between the conical surface 14d of the planetary cone 5 and the sun roller 7 and a contact position P2 between the conical surface 15d of the planetary cone 5 and the ring roller 6 are located at the same position in the axial direction of the input shaft 2. In other words, the sun roller 7 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. Therefore, the contact pressure of the sun roller 7 and the ring roller 6 does not generate a rotational moment that tilts the axis center 16r of the planetary cone 5.

[0105] In the continuously variable transmission 1 of this embodiment, a contact position P1 of the sun roller 7 with the conical surface 14d of the planetary cone 5 and a contact position P2 of the ring roller 6 with the conical surface 15d of the planetary cone 5 each extend approximately parallel to the input shaft 2. In other words, the contact surfaces of the sun roller 7 and the ring roller 6 with respect to the planetary cone 5 have a cylindrical shape extending approximately parallel to the input shaft 2.

[0106] Next, the operation of the continuously variable transmission 1 will be described. The rotational power of the driving power source 10 is transmitted to the input shaft 2 of the continuously variable transmission 1, and then transmitted from the sun roller 7 integral with the input shaft 2 to the input side planetary cone 14. Since a ball cam mechanism 21 is provided between the input side planetary cone 14 and the output side planetary cone 15, the rotational power of the driving power source 10 is transmitted from the input side planetary cone 14 to the output side planetary cone 15 via the sphere 20, and then the rotational power is transmitted from the output side planetary cone 15 to the ring roller 6. That is, the planetary cone 5 rotates together with the support shaft 16 due to the rotation of the sun roller 7, and the rotational power of the planetary cone 5 is transmitted to the ring roller 6.

[0107] 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 via the final drive gear to the final driven gear of the differential device, 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.

[0108] In the continuously variable transmission 1, a rotational force (driving force) is transmitted as follows, and at the same time, a speed change (conversion of rotational speed) is performed. The rotational speed of the sun roller 7 is transmitted to the input side planetary cone 14, and the planetary cone 5 rotates at a rotational speed changed in accordance with the ratio between the radius of the sun roller 7 and the radius of the contact point 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 a rotational speed changed in accordance with the ratio between the radius of the ring roller 6 and the radius of the contact point on the planetary cone 5.

[0109] As shown in Fig. 1, when the continuously variable transmission 1 is in high speed, the planetary cone 5 is moved to the position furthest to the left from the output shaft 3 by the moving mechanism 30 (the leftmost position within the movable range of the planetary cone 5), and the sun roller 7 comes into contact with the smallest diameter conical surface 14d of the input side planetary cone 14. At this time, the ring roller 6 comes into contact with 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 7 is accelerated by the planetary cone 5 and transmitted to the ring roller 6. This is the state in which the gear ratio of the continuously variable transmission 1 is smallest.

[0110] As shown in Fig. 3, when the continuously variable transmission 1 is in a low speed state, the planetary cone 5 is moved by the moving mechanism 30 to the position closest to the output shaft 3 (the rightmost position within the movable range of the main carrier 4), and the sun roller 7 comes into contact with the largest-diameter conical surface 14d on the bottom surface 14b side of the input-side planetary cone 14. At this time, the ring roller 6 comes into contact with the smallest-diameter conical surface 15d of the output-side planetary cone 15. As a result, the rotational speed of the sun roller 7 is reduced by the planetary cone 5 and transmitted to the ring roller 6. This is the state in which the speed ratio of the continuously variable transmission 1 is greatest.

[0111] In other words, the continuously variable transmission 1 is capable of continuously changing the rotational speed (rotational power) of the input shaft 2 to the output shaft 3 via the planetary cones 5 by changing the contact position P1 between the conical surface 14d of the input side planetary cone 14 and the sun roller 7, and the contact position P2 between the conical surface 15d of the output side planetary cone 15 and the ring roller 6 using the main carrier 4.

[0112] An oil film (not shown) is formed at a contact position P1 between the sun roller 7 and the conical surface 14d of the input planetary cone 14 and at a contact position P2 between the ring roller 6 and the conical surface 15d of the output planetary cone 15. This allows power to be transmitted from the sun roller 7 to the input planetary cone 14 via the oil film, and from the ring roller 6 to the output planetary cone 15 via the oil film.

[0113] The input side planetary cone 14 is disposed so that its conical surface 14d extends parallel to the axis 2r of the input shaft 2 and is in constant contact with the sun roller 7. The output side planetary cone 15 is disposed so that its conical surface 15d extends parallel to the axis 2r of the input shaft 2 and is in constant contact with the ring roller 6.

[0114] This allows the planetary cone 5 to move parallel to the conical surfaces 14d and 15d relative to the sun roller 7 and ring roller 6 during gear shifting, preventing excessive friction between the sun roller 7 and conical surface 14d, and between the ring roller 6 and conical surface 15d, thereby enabling smooth gear shifting.

[0115] 1, the input side planetary cone 14 and the output side planetary cone 15 have the same shape, having the same outer diameter shape and the same cam groove shape, so when the torque input to the input side planetary cone 14 is small, the sphere 20 is located at the deepest position in the circumferential center of the input side cam groove 14f and the output side cam groove 15f of the input side planetary cone 14. In other words, the input side planetary cone 14 and the output side planetary cone 15 are at their closest positions.

[0116] In this case, the input side planetary cone 14 and the output side planetary cone 15 rotate together. In this state, torque is transmitted from the input side planetary cone 14 to the output side planetary cone 15 via the sphere 20.

[0117] This state is under light load, and the contact pressure between the conical surface 14d of the input planetary cone 14 and the sun roller 7, and the contact pressure between the conical surface 15d of the output planetary cone 15 and the ring roller 6 are adjusted to an appropriate level that does not cause slippage. This is largely due to the spring 5A.

[0118] On the other hand, when the torque input to the input side planetary cone 14 increases (i.e., when the output side planetary cone 15 becomes difficult to rotate relative to the rotation of the input side planetary cone 14), the output side planetary cone 15 starts to lag behind the input side planetary cone 14. In other words, the entire planetary cone 5 is in a twisted state. In other words, the output side planetary cone 15 cannot follow the rotation of the input side planetary cone 14, and the input side planetary cone 14 shifts relative to the output side planetary cone 15 in the rotational direction.

[0119] Power is transmitted between the input side planetary cone 14 and the output side planetary cone 15 via the sphere 20, but due to this relative misalignment, the sphere 20 moves from the deep part (the center in the circumferential direction) of the input side cam groove 14f and the output side cam groove 15f to the shallow part (one side in the circumferential direction), causing the input side planetary cone 14 and the output side planetary cone 15 to move apart in the axial direction of the support shaft 16.

[0120] This is because the input side cam groove 14f and the output side cam groove 15f act like cam inclined surfaces with respect to the ball 20, generating a repulsive force and movement according to the torque like a torque cam.

[0121] As a result, the input side planetary cone 14 and the output side planetary cone 15 move in directions away from each other on the support shaft 16.

[0122] Therefore, when the torque (input load) transmitted by the planetary cone 5 increases, the contact pressure between the conical surface 14d of the input planetary cone 14 and the sun roller 7, and the contact pressure between the conical surface 15d of the output planetary cone 15 and the ring roller 6 increase.

[0123] In addition, rather than simply defining the shape of the change in groove depth in input side cam groove 14f and output side cam groove 15f as an inclination angle, the inclination may be changed so that the inclination becomes greater from the circumferential center of input side cam groove 14f and output side cam groove 15f to the circumferential ends.

[0124] Since the sphere 20 is located in the circumferential center 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 opposite direction to the above-mentioned rotational direction with respect to the output side planetary cone 15, the sphere 20 can be moved from the circumferential center of the input side cam groove 14f and the output side cam groove 15f in the opposite direction to the above-mentioned direction, separating the input side planetary cone 14 and the output side planetary cone 15 in the axial direction of the support shaft 16. This makes it possible to increase the contact surface pressure at the contact positions P1 and P2 only when necessary.

[0125] Next, the effect of the continuously variable transmission 1 of this embodiment will be described. In the continuously variable transmission 1 of this embodiment, the planetary cone 5 has an input side planetary cone 14 with which the sun roller 7 comes into contact, an output side planetary cone 15 provided separately from the input side planetary cone 14 with which the ring roller 6 comes into contact, and a ball cam mechanism 21 that connects the bottom surface 14b of the input side planetary cone 14 with 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, a sphere 20 accommodated between the input side cam groove 14f and the output side cam groove 15f, and a retainer 22 that is disposed between the input side cam groove 14f and the output side cam groove 15f and holds the sphere 20. The input-side cam groove 14f and the output-side cam groove 15f extend in the circumferential and radial directions about the axis of the support shaft 16, and are shallower toward the circumferential ends and toward the radially outward side. The cage 22 holds the sphere 20 so as to be movable radially outward from the planet cone 5.

[0126] As a result, the ball 20 of the ball cam mechanism 21 is held by the retainer 22 so as to be movable radially outward from the planetary cone 5. Therefore, the ball 20 can move radially outward by centrifugal force between the gradually narrowing input side cam groove 14f and the output side cam groove 15f to a position where there is no gap (backlash). Therefore, there is no gap between the ball 20 and the input side cam groove 14f and the output side cam groove 15f for each of the multiple ball cam mechanisms 21, and manufacturing errors can be absorbed, thereby improving durability and reliability. In addition, productivity can be improved because a decrease in productivity when trying to reduce manufacturing errors can be avoided. As a result, productivity, durability, and reliability can be improved.

[0127] In the continuously variable transmission 1 of this embodiment, the retainer 22 has a notch 22A that retains the sphere 20 therein and regulates the position of the sphere 20, and an edge 22B of the notch 22A that faces the input side planetary cone 14 or the output side planetary cone 15 is narrowed so that the sphere 20 cannot pass through. The ball cam mechanism 21 also includes a spring 5A that biases the retainer 22 against the output side planetary cone 15.

[0128] As a result, the retainer 22 holding the spheres 20 is biased by the spring 5A toward the output side planetary cone 15. Therefore, the planetary cone 5 can be assembled with the spheres 20 positioned in the deepest parts of the input side cam groove 14f and the output side cam groove 15f, and therefore, in the assembled state of the planetary cone 5 with each member assembled to the support shaft 16, the retainer 22 and the spring 5A act to prevent the spheres 20 from falling out from between the input side planetary cone 14 and the output side planetary cone 15. This improves the ease of assembly.

[0129] In addition, in the continuously variable transmission 1 of this embodiment, the left end 16A of the support shaft 16 is expanded in diameter to prevent the output side planetary cone 15 from falling off, and the planetary cone 5 is partially assembled in a state in which the output side planetary cone 15, the sphere 20, the retainer 22, the spring 5A, and the input side planetary cone 14 are attached from the right end 16B side of the support shaft 16.

[0130] This allows an assembly of multiple planetary cones 5 to be produced in advance by assembling each member to the support shaft 16. Also, the assemblies of multiple planetary cones 5 that have been produced in advance can be simultaneously assembled to the main carrier 4. This improves the ease of assembly.

[0131] Although an embodiment of the invention has been disclosed, it will be apparent to one of ordinary skill in the art that modifications may be made thereto without departing from the spirit and scope of the invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0132] 1...Continuously variable transmission, 2...Input shaft, 3...Output shaft, 5...Planetary cone, 5A...Spring (elastic member), 6...Ring roller, 7...Sun roller, 10...Drive source, 14...Input side planetary cone (planetary cone), 14b...Bottom surface, 14d...Conical surface, 14f...Input side cam groove, 15...Output side planetary cone (planetary cone), 15b...Bottom surface, 15d...Conical surface, 15f...Output side cam groove, 16...Support shaft, 16A...Left end (other end), 16B...Right end (one end), 20...Sphere, 21...Ball cam mechanism, 22...Cage, 22A...Notch portion, 22B...Edge portion, 30...Moving mechanism

Claims

1. a sun roller provided on an input shaft to which rotational power is input from a driving power source; a ring roller that transmits the input rotational power to an output shaft; a planetary cone having a conical surface in contact with the sun roller or the ring roller and formed in a truncated cone shape; A support shaft that rotatably supports the planetary cone; A continuously variable transmission including: a moving mechanism that changes a contact position of the sun roller on a conical surface of the planetary cone and a contact position of the ring roller on the conical surface of the planetary cone so as to continuously change the speed of the rotational power of the input shaft to the output shaft via the planetary cone; The planetary cone is an input side planetary cone with which the sun roller comes into contact; an output side planetary cone provided separately from the input side planetary cone and in contact with the ring roller; a ball cam mechanism that connects a bottom surface of the input side planetary cone and a 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 includes: an input side cam groove formed on a bottom surface of the input side planetary cone; an output side cam groove formed on a bottom surface of the output side planetary cone; a sphere accommodated between the input cam groove and the output cam groove; a retainer disposed between the input cam groove and the output cam groove and holding the sphere; The input side cam groove and the output side cam groove are The support shaft extends in a circumferential direction and a radial direction around the axis of the support shaft, The grooves are formed shallower toward the ends in the circumferential direction and shallower toward the outside in the radial direction, 11. A continuously variable transmission, comprising: a cage that holds the sphere so as to be movable in a radial direction of the planetary cone;

2. the retainer has a notch portion that holds the sphere therein and regulates the position of the sphere, an edge of the cutout portion facing the input planetary cone or the output planetary cone is narrowed so that the sphere cannot pass through; 2. The continuously variable transmission according to claim 1, wherein the ball cam mechanism includes an elastic member that biases the cage against the input planetary cone or the output planetary cone.

3. The other end of the support shaft is expanded in diameter to prevent the output side planetary cone from coming off, 3. The continuously variable transmission according to claim 2, wherein the planetary cones are assembled in a state in which the output side planetary cone, the sphere, the retainer, the elastic member, the input side planetary cone, and the sleeve are assembled from one end side of the support shaft.

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