Continuously variable transmission

Abstract

To provide a continuously variable transmission capable of easily improving position accuracy of each component, and improving durability.SOLUTION: An input shaft 2 has a cylindrical part 2A formed into a cylindrical shape on a right end side. An inner periphery of the cylindrical part 2A supports a left end 3A of an output shaft 3, and an outer periphery of the cylindrical part 2A supports an inner carrier 34. The cylindrical part 2A is a maximum diameter portion of the input shaft 2, and the input shaft 2 is formed to have a smaller diameter from the right end to the left end. A step part 2C is formed on an end face of the cylindrical part 2A on a let end side, and the step part 2C positions a sun roller 7 in an axial direction in contact with the right end side in an axial direction of the sun roller 7. The sun roller 7 is positioned in the axial direction between the step part 2C and a bearing 62.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 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 via 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. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-054007 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional continuously variable transmissions, the support positions between the carrier that holds the support shaft, the sun roller as the input member, and the ring roller as the output member are spaced apart on the axis of the input shaft, so that the effect of component accuracy on positioning accuracy is significant, and there was room for further consideration to avoid a decrease in durability due to stress concentration, etc.

[0005] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a continuously variable transmission capable of easily improving the positional accuracy of each component and improving durability. [Means for solving the problem]

[0006] In order to solve the above problem, 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 driving force source; a ring roller that transmits the input rotational power to an output shaft; a planetary cone formed in a truncated cone shape having a conical surface that contacts the sun roller or the ring roller; a support shaft that rotatably supports the planetary cone; and a moving mechanism that changes 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 output shaft is coaxially arranged on one end side of the input shaft and is provided with an inner carrier that rotatably holds one end of the support shaft, the input shaft has a cylindrical portion formed in a cylindrical shape on one end side, the inner surface of the cylindrical portion supports the other end of the output shaft, and the outer surface of the cylindrical portion supports the inner carrier. Effect of the Invention

[0007] Thus, according to the present invention, it is possible to provide a continuously variable transmission that can easily improve the positional accuracy of each component and improve durability. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view of the central axis of rotation of an input shaft and the axis of a support shaft at a planetary cone position when an output shaft rotates at a high speed relative to the rotation speed of an input shaft of a continuously variable transmission according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of the rotational center axis of the input shaft and the axis of the connecting member in one embodiment of the present invention at the planetary cone position in FIG. [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 the planetary cone position when the output shaft rotates at a slow speed relative to the rotational speed of the input shaft of a continuously variable transmission according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A continuously variable transmission according to an embodiment of the present invention includes a sun roller provided on an input shaft to which a rotational power is input from a driving 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, the continuously variable transmission is characterized in that an output shaft is coaxially arranged on one end side of the input shaft, and an inner carrier is provided for rotatably holding one end of the support shaft, the input shaft has a cylindrical portion formed in a cylindrical shape at one end side, the inner peripheral surface of the cylindrical portion supports the other end of the output shaft, and the outer peripheral surface of the cylindrical portion supports the inner carrier. As a result, the continuously variable transmission according to an embodiment of the present invention can easily improve the positional accuracy of each component and improve durability. 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 3 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 FIG. 1 to FIG. 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 FIG. 1 and FIG. 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 disposed 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 arranged and into the range in which the ring roller 6 is arranged. 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).

[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 now be described. Some of the bearings 17, of which there are several for each planetary cone 5, are located high up inside the transmission case 41, but they are located at approximately the same position as the ring roller 6 with respect to the input shaft 2 and are located near the inner wall in the internal space of the continuously variable transmission 1, so that oil that circulates around the inner surface of the transmission case 41 is supplied by the rotation of the ring roller 6.

[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. The oil pump pumps oil into the axial hole 2H of the input shaft 2 and reaches the inner diameter hole of the cylindrical portion 2A at the right end, and flows into the opening of the axial hole 3H of the output shaft 3, which is disposed opposite the opening of the axial hole 2H formed in the cylindrical portion 2A. At this time, oil leaks out from between the input shaft 2 and the output shaft 3, and the leaked oil from the axial hole 2H of the input shaft 2 is supplied to the bearing 51 between the input shaft 2 and the output shaft 3. The bearing 51 is disposed on the right end side of the first oil passage 2D and the second oil passage 2E, in an expanded diameter portion formed near the right end opening of the inner diameter hole of the cylindrical portion 2A into which the left end 3A of the output shaft 3 is inserted.

[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 bearings 61, 62 between the handle shaft 31B and the input shaft 2 through the shaft hole 2H of the input shaft 2. The oil between the handle shaft 31B and the input shaft 2 is discharged from the right end of the handle shaft 31B. This discharged oil collides with the side surface of the sun roller 7, flows along the side surface of the sun roller 7 and splashes around. The oil discharged from the right end of the handle shaft 31B is then supplied to the conical surface 14d of the input side planetary cone 14. In addition, since the outer edge of the opposing surfaces (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 in 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 state positions, the outer edge of the opposing surfaces (bottom surfaces 14b, 15b) between the input side planetary cone 14 and the output side planetary cone 15 is positioned to face the recess 6B in the inner peripheral surface of the ring roller 6, so the oil present in the recess 6B is efficiently supplied to the ball cam mechanism 21.

[0035] A flange-shaped expanded diameter portion 3B that protrudes in the radial direction is formed in the longitudinal center of the output shaft 3, and the inner diameter of the disk-shaped output drum 8 is fixed to the outer periphery of this expanded diameter portion 3B by welding or the like. In other words, the output drum 8 is disposed coaxially with the input shaft 2, and rotates integrally with the output shaft 3 that penetrates through it. The output drum 8 is disposed close to the right-most light case 43 in the internal space of the transmission case 41, 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 to it with a bolt 6A. In detail, a fitting portion is formed on the outer edge of the output drum 8, and the outer edge of the output drum 8 is overlapped with the end face of the ring roller 6, and the output drum 8 is attached to the end face of the ring roller 6 with the bolt 6A that is tightened in the axial direction.

[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 for extracting the changed driving force is attached to the right end of the output shaft 3 by spline fitting. In detail, a splined shaft formed at the right end of the output shaft 3 is fitted into a splined hole of the flange 55, and the flange 55 is prevented from coming off by a washer fixed by a bolt fastened to the right end of the output shaft 3. A propeller shaft (not shown) and the like are connected to the flange 55, and the driving force output from the flange 55 is transmitted to a differential device. The differential device is connected to left and right driving wheels via left and right drive shafts (not shown). The differential device distributes the rotational power of the driving force source 10 transmitted from the output shaft 3 to the left and right drive shafts, and transmits it to the left and right driving 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 rotatably supported by the support shaft 16 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 now be described. The continuously variable transmission 1 has a disk-shaped cage 22 disposed between the input planetary cone 14 and the output planetary cone 15, and this cage 22 holds the spheres 20. The cage 22 holds the spheres 20 so as to be movable radially outward from the planetary cone 5. The cage 22 also holds the spheres 20 so as to restrict the movement of the planetary cone 5 in the circumferential direction.

[0079] The cage 22 has a notch (not shown) that holds the sphere 20 therein and regulates the position of the sphere 20. The edge of this notch facing the input side planetary cone 14 or the output side planetary cone 15 is narrowed so that the sphere 20 cannot pass through.

[0080] The spring 5A will be described. 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. More specifically, the spring 5A is provided between the bottom surface 14b of the input side planetary cone 14 and the retainer 22. The spring 5A biases the retainer 22 to press against the output side planetary cone 15 by a restoring force (biasing force). The restoring force of the spring 5A acts in a direction that separates the input side planetary cone 14 and the output side planetary cone 15.

[0081] Even when the planetary cone 5 is not transmitting torque, the restoring force of the spring 5A presses the input side planetary cone 14 against the sun roller 7 and presses the output side planetary cone 15 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.

[0082] 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.

[0083] 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.

[0084] The shape and installation position of spring 5A are determined so as to avoid interference with input side cam groove 14f, output side cam groove 15f, and sphere 20 and not to affect the operation of ball cam mechanism 21, and spring 5A is attached to input side planetary cone 14 or output side planetary cone 15.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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 gearshift 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 at the right end of the handle shaft 31B of the gearshift operating unit 31 and the outer circumferential surface of the input shaft 2. In other words, a seal member 64 and bearing 61 are provided side by side between the inner circumferential surface at the left end of the handle shaft 31B of the gearshift operating unit 31 and the outer circumferential surface of the input shaft 2.

[0101] A bearing 53 made of a ball bearing is provided on the outer circumferential surface near the left end of the handle shaft 31B of the gear shift operating part 31 and to the right of the seal member 65. The inner circumferential portion (inner ring) of the bearing 53 is fitted to the handle shaft 31B. The outer circumferential portion (outer ring) of the bearing 53 is fitted to the inner circumferential surface of the left end of the left case 42 of the transmission case 41. In other words, the seal member 65 and the bearing 53 are provided side by side on the left and right between the outer circumferential surface of the left end of the handle shaft 31B of the gear shift operating part 31 and the inner circumferential surface of the left end of the left case 42 of the transmission case 41. The seal member 64, the bearing 61, the seal member 65, and the bearing 53 are all arranged coaxially with the axis 2r of the input shaft 2.

[0102] In this manner, in this embodiment, the gear shift operating unit 31 is rotatably supported by the bearing 53 relative to the transmission case 41. Also, a left end portion of the input shaft 2 is rotatably supported by the bearings 61 and 62 relative to the gear shift operating unit 31. An oil circulation hole that connects the space between the seal member 64 and the bearing 61 and the space between the seal member 65 and the bearing 53 may be provided in the handle shaft 31B to lubricate the bearings 61 and 53. Also, in order to lubricate the bearing 50, an oil circulation hole through which oil is supplied from the shaft hole 3H of the output shaft 3 between the bearing 50 and the seal member 66 may be provided in the output shaft 3 to lubricate the bearing 50.

[0103] 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.

[0104] 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 surface shape coaxial with the input shaft 2.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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 small-diameter conical surface 14d of the input-side planetary cone 14. At this time, the ring roller 6 comes into contact with the large-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.

[0109] 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 large-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 small-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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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 output shaft 3 is coaxially arranged on the right end side of the input shaft 2, and the inner carrier 34 rotatably holds the right end of the support shaft 16. The input shaft 2 has a cylindrical portion 2A formed in a cylindrical shape on the right end side, and a small diameter portion 2B formed on the left end side with a smaller diameter than the cylindrical portion 2A. The inner peripheral surface of the cylindrical portion 2A supports the left end portion 3A of the output shaft 3, and the outer peripheral surface of the cylindrical portion 2A supports the inner carrier 34.

[0125] As a result, both the output shaft 3 and the inner carrier 34 can be positioned and supported by the cylindrical portion 2A of the input shaft 2, so that the input shaft 2, the inner carrier 34, and the output shaft 3 can be accurately and easily positioned relative to one another. As a result, the positional accuracy of each component can be easily improved, and the durability of the continuously variable transmission 1 can be improved.

[0126] In the continuously variable transmission 1 of this embodiment, the cylindrical portion 2A is the portion of the input shaft 2 with the maximum diameter, and the input shaft 2 is formed with a smaller diameter from the right end to the left end. A step portion 2C is formed on the end face on the other end side of the cylindrical portion 2A, and the step portion 2C abuts against a side surface on the axial right end side of the sun roller 7 to position the sun roller 7 in the axial direction. A bearing 62 that supports the input shaft 2 is disposed on the axial left end side of the sun roller 7, and the sun roller 7 is positioned by being sandwiched between the step portion 2C and the bearing 62 in the axial direction.

[0127] This makes it possible to accurately position the sun roller 7 in the axial direction relative to the input shaft 2. In addition, since the sun roller 7 is positioned in the vicinity of the cylindrical portion 2A, it is possible to easily improve the accuracy of positioning the sun roller 7 relative to the cylindrical portion 2A.

[0128] In the continuously variable transmission 1 of this embodiment, the sun roller 7 has an inner peripheral edge portion 7A fixed to the input shaft 2, and an outer peripheral edge portion 7B disposed axially biased toward the right end side from the inner peripheral edge portion 7A so as to surround the other end of the inner carrier 34 and the other end of the cylindrical portion 2A from the outer periphery side. The outer peripheral edge portion 7B of the sun roller 7 and the other 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.

[0129] In this way, the positional accuracy can be improved by disposing the outer peripheral edge portion 7B of the sun roller 7 and the other end of the inner carrier 34 at the same position as the cylindrical portion 2A in the axial direction of the input shaft 2. Also, the load acting radially inward from the outer peripheral edge portion 7B of the sun roller 7 and the other end of the inner carrier 34 can be supported at the same position on the cylindrical portion 2A, thereby improving the positional accuracy.

[0130] 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]

[0131] 1...Continuously variable transmission, 2...Input shaft, 2A...Cylindrical portion, 2B...Small diameter portion, 2C...Step portion, 3...Output shaft, 3A...Left end portion (other end portion), 4...Main carrier, 5...Planetary cone, 6...Ring roller, 7...Sun roller, 7A...Inner peripheral portion, 7B...Outer peripheral portion, 10...Driving force source, 14...Input side planetary cone (planetary cone), 14d...Conical surface, 15...Output side planetary cone (planetary cone), 15d...Conical surface, 16...Support shaft, 16A...Left end portion (other end portion), 16B...Right end portion (one end portion), 30...Moving mechanism, 34...Inner carrier, 62...Bearing

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 output shaft is coaxially disposed on one end side of the input shaft, an inner carrier that rotatably holds one end of the support shaft; The input shaft has a cylindrical portion formed in a cylindrical shape at one end side, an inner circumferential surface of the cylindrical portion supports the other end of the output shaft; The outer circumferential surface of the cylindrical portion supports the inner carrier.

2. the cylindrical portion is a portion of the input shaft with a maximum diameter, The input shaft is formed so that its diameter decreases from one end to the other end, A step portion is formed on the other end surface of the cylindrical portion, the step portion abuts against a side surface of one axial end of the sun roller to position the sun roller in the axial direction, A bearing for supporting the input shaft is disposed on the other axial end side of the sun roller, 2. The continuously variable transmission according to claim 1, wherein the sun roller is positioned by being sandwiched in the axial direction between the stepped portion and the bearing.

3. The sun roller is An inner peripheral edge portion fixed to the input shaft; an outer circumferential edge portion disposed so as to be biased toward one end in the axial direction relative to the inner circumferential edge portion so as to surround the other end of the inner carrier and the other end of the cylindrical portion from an outer circumferential side, 3. The continuously variable transmission according to claim 1, wherein the outer peripheral edge portion of the sun roller and the other end portion of the inner carrier are disposed at the same position as the cylindrical portion in the axial direction of the input shaft.

Images