JPWO2019087915A1 - Continuously variable transmission and bicycle - Google Patents

Abstract

This continuously variable transmission has a plurality of planetary rollers arranged around a spindle. Both ends of the rotating shaft of the planetary roller are held so as to be displaceable in the radial direction with respect to the main shaft. Each planet roller has a first inclined surface in contact with the input rotating body and a second inclined surface in contact with the output rotating body. The tilt angle of the planetary rollers changes according to the axial position of the movable ring. Then, the contact position of the first inclined surface with respect to the input rotating body and the contact position of the second inclined surface with respect to the output rotating body change, respectively. As a result, the gear ratio between the input rotating body and the output rotating body can be switched. Further, the first inclined surface of the planetary roller is spherical. Therefore, regardless of the inclination angle of the planetary roller, the direction and magnitude of the pressure generated at the contact point between the first inclined surface and the input rotating body are unlikely to change.

Description

The present invention relates to continuously variable transmissions and bicycles.

Conventionally, a bicycle having a transmission mechanism is known. A general transmission mechanism for a bicycle has a structure in which a roller chain is exchanged between a plurality of sprockets having different diameters. When the bicycle user operates the shift lever on the handlebar, the roller chain is replaced with the sprocket designated by the shift lever. As a result, the rear wheels rotate at a gear ratio according to the diameter of the sprocket. However, in such a general transmission mechanism, the gear ratio can be switched only by the number of gears according to the number of sprockets.

On the other hand, Japanese Patent Application Laid-Open No. 2016-70393 describes a transmission for a bicycle capable of continuously changing the gear ratio. The transmission of the present publication changes the ratio of the rotation speeds of the first rolling element and the second rolling element by inclining the support pins of the planet rollers arranged around the spindle.
Japanese Unexamined Patent Publication No. 2016-70393

However, in the transmission of JP2016-70393, the rolling surface on the input side of the planetary roller is a conical surface. Therefore, the angle of the rolling surface on the input side also changes depending on the inclination angle of the planetary roller. As a result, the direction and magnitude of the pressure applied to the rolling surface on the input side change significantly. If the pressure applied to the rolling surface on the input side becomes excessive, the resistance increases and the efficiency of power transmission tends to decrease. Further, if the pressure applied to the rolling surface on the input side becomes too small, the planetary roller tends to slip.

An object of the present invention is to provide a structure in which the direction and magnitude of pressure generated at a contact point between a planetary roller and an input rotating body are difficult to change in a continuously variable transmission that switches a gear ratio by changing the inclination angle of the planetary roller. The purpose is to provide.

An exemplary first invention of the present application is a stepless transmission, which rotates around a spindle at a rotation speed before shifting and an input rotating body around the spindle at a rotation speed after shifting. An output rotating body, a plurality of planetary rollers arranged around the main shaft and capable of rotating around the rotation shaft, a guide member that limits the positions of both ends of the rotation shaft, and a guide member that can rotate around the main shaft. The planetary roller is provided with an annular movable ring that is movable in the axial direction and has a spherical first inclined surface that contacts the input rotating body and a conical shape that contacts the output rotating body. The guide member holds both ends of the rotation shaft at different positions in the circumferential direction, and has an annular concave portion or an annular convex portion that engages with the movable ring. Both ends of the shaft are held by the guide member so as to be radially displaceable with respect to the main shaft.

According to the first exemplary invention of the present application, the inclination angle in the cross section including the main axis of the rotation axis of the planetary roller changes depending on the position of the movable ring in the axial direction. Then, the contact position of the first inclined surface with respect to the input rotating body and the contact position of the second inclined surface with respect to the output rotating body change, respectively. As a result, the gear ratio between the input rotating body and the output rotating body can be switched.

Further, according to the exemplary first invention of the present application, the first inclined surface of the planetary roller is spherical. Therefore, regardless of the inclination angle of the planetary roller, the direction and magnitude of the pressure generated at the contact point between the first inclined surface and the input rotating body are unlikely to change.

FIG. 1 is a schematic view of a bicycle. FIG. 2 is a vertical cross-sectional view of the continuously variable transmission. FIG. 3 is a vertical cross-sectional view of the continuously variable transmission. FIG. 4 is a vertical cross-sectional view of the continuously variable transmission. FIG. 5 is a side view of the pressure adjusting cam. FIG. 6 is a side view of the pressure adjusting cam. FIG. 7 is an exploded cross-sectional view of the planetary roller. FIG. 8 is a diagram showing the pressure generated at the contact point between the second cam member and the first inclined surface and the contact point between the contact member and the second inclined surface. FIG. 9 is a diagram showing the pressure generated at the contact point between the second cam member and the first inclined surface and the contact point between the contact member and the second inclined surface. FIG. 10 is a diagram showing the pressure generated at the contact point between the second cam member and the first inclined surface and the contact point between the contact member and the second inclined surface. FIG. 11 is a diagram showing a planetary roller and a movable ring according to the first modification. FIG. 12 is a vertical cross-sectional view of the continuously variable transmission according to the second modification. FIG. 13 is a plan view of the first guide plate and the second guide plate according to the second modification as viewed from one side of the main shaft. FIG. 14 is a view of the planetary roller according to the second modification as viewed from the outside in the radial direction. FIG. 15 is a vertical cross-sectional view of the continuously variable transmission according to the third modification.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In the present application, the direction parallel to the spindle of the continuously variable transmission is referred to as "axial direction", the direction orthogonal to the spindle is referred to as "diameter direction", and the direction along the arc centered on the spindle is referred to as "circumferential direction". .. However, the above-mentioned "parallel direction" also includes a substantially parallel direction. Further, the above-mentioned "orthogonal direction" includes a direction substantially orthogonal to each other. Further, in the present application, among both ends in the axial direction of the member, the end portion close to the sprocket is referred to as "one end", and the end portion far from the sprocket is referred to as "the other end".

<1. About bicycles>
FIG. 1 is a schematic view of a bicycle 100 using the continuously variable transmission 1 according to the embodiment of the present invention. As shown in FIG. 1, the bicycle 100 has a front wheel 110, a rear wheel 120, a pedal 130, a roller chain 140, and a continuously variable transmission 1. The continuously variable transmission 1 is installed in a hub provided in the center of the wheel 121 of the rear wheel 120. When the user pedals the pedal 130 in the forward direction, the rotational movement of the pedal 130 is transmitted to the continuously variable transmission 1 via the roller chain 140. Further, the continuously variable transmission 1 shifts the rotational motion received from the roller chain 140 and transmits it to the rear wheels 120. The rear wheel 120 rotates at the rotation speed changed by the continuously variable transmission 1. The bicycle 100 may have an electric motor for assisting the rotational movement of the pedal 130.

<2. Continuously variable transmission configuration>
2 to 4 are vertical cross-sectional views of the continuously variable transmission 1. The continuously variable transmission 1 is a mechanism that outputs the rotational motion obtained from the roller chain 140 to the rear wheels 120 at a constant speed, or by decelerating or increasing the speed. FIG. 2 shows a cross section of the continuously variable transmission 1 at a constant speed. FIG. 3 shows a cross section of the continuously variable transmission 1 during deceleration. FIG. 4 shows a cross section of the continuously variable transmission 1 at the time of speed increase. As shown in FIGS. 2 to 4, the continuously variable transmission 1 of the present embodiment has a hollow shaft 10, an input rotating body 20, a plurality of planetary rollers 30, a guide member 40, a movable ring 50, an operation unit 60, and an output. It has a rotating body 70.

The hollow shaft 10 is a columnar member extending along the main shaft 9. As the material of the hollow shaft 10, for example, a metal such as stainless steel is used. The input rotating body 20, the movable ring 50, and the output rotating body 70, which will be described later, are supported by the hollow shaft 10 via bearings. When the continuously variable transmission 1 is attached to the bicycle 100, the continuously variable transmission 1 is arranged so that the main shaft 9 which is the central axis of the hollow shaft 10 and the central axis of the rear wheels 120 coincide with each other.

The input rotating body 20 rotates about the spindle 9 as the roller chain 140 rotates. As shown in FIGS. 2 to 4, the input rotating body 20 of this embodiment has a sprocket 21, a relay member 22, and a pressure adjusting cam 23.

The relay member 22 has a cylindrical portion 221 and a flange portion 222. The cylindrical portion 221 extends axially in a cylindrical shape around the hollow shaft 10. The flange portion 222 extends radially outward from the axial end of the cylindrical portion 221. The flange portion 222 is located inside the housing 72, which will be described later. A pair of first bearings 24 are provided between the relay member 22 and the hollow shaft 10. For the first bearing 24, for example, a ball bearing is used. The relay member 22 is rotatably supported with respect to the hollow shaft 10 via the first bearing 24.

The sprocket 21 is fixed to the outer peripheral surface of the cylindrical portion 221. The roller chain 140 of the bicycle 100 engages with a plurality of teeth provided on the outer peripheral surface of the sprocket 21. When the bicycle 100 is running, the sprocket 21 and the relay member 22 rotate around the main shaft 9 at the rotation speed before shifting as the roller chain 140 rotates. Hereinafter, the rotation speed of the sprocket 21 and the relay member 22 will be referred to as a “first rotation speed”.

The pressure adjusting cam 23 is a mechanism for generating an axial pressing force on the planet roller 30 according to a load in the rotational direction. The pressure adjusting cam 23 has a first cam member 231 and a second cam member 232 arranged in the axial direction, and a plurality of rolling elements 233. The first cam member 231 and the second cam member 232 are annular members centered on the spindle 9. The first cam member 231 and the flange portion 222 of the relay member 22 are fixed to each other by, for example, screwing. The plurality of rolling elements 233 are spherical members interposed between the first cam member 231 and the second cam member 232.

5 and 6 are side views of the pressure adjusting cam 23. As shown in FIGS. 5 and 6, the first cam member 231 and the second cam member 232 each have a plurality of first cam surfaces 23a and a plurality of second cam surfaces 23b. The rolling element 233 is accommodated in the space between the first cam surface 23a and the second cam surface 23b of the first cam member 231 and the first cam surface 23a and the second cam surface 23b of the second cam member 232. ..

The angle of the first cam surface 23a with respect to the circumferential direction is smaller than the angle of the second cam surface 23b with respect to the circumferential direction. The angle of the first cam surface 23a with respect to the circumferential direction may be, for example, 3 ° or more and 35 ° or less. The angle of the second cam surface 23b with respect to the circumferential direction may be, for example, 70 ° or more and less than 90 °.

When the user of the bicycle 100 pedals the pedal 130, the input rotating body 20 rotates in the forward direction. At this time, as shown in FIG. 5, each rolling element 233 is in contact with the first cam surface 23a of the first cam member 231 and the first cam surface 23a of the second cam member 232, while the first cam surface 23a. Displace in the direction of riding along. Then, the rolling element 233 moves the second cam member 232 in the direction away from the first cam member 231 as a reference. Therefore, the contact pressure between the second cam member 232 and the first inclined surface 301 described later of the planetary roller 30 increases.

On the other hand, when the user of the bicycle 100 rotates the pedal 130 in the opposite direction or at a speed smaller than that of the rear wheel 120, the input rotating body 20 also rotates in the opposite direction. At this time, as shown in FIG. 6, each rolling element 233 comes into contact with the second cam surface 23b of the first cam member 231 and the second cam surface 23b of the second cam member 232. Then, the rolling element 233 does not change the positional relationship between the second cam surface 23b of the first cam member 231 and the second cam surface 23b of the second cam member 232 in the circumferential direction and the axial direction, and the first cam member 231 And the second cam member 232 rotate integrally. Therefore, the contact pressure between the second cam member 232 and the first inclined surface 301 described later of the planetary roller 30 is weakened. As a result, the input rotating body 20 and the output rotating body 70 idle. In other words, the pressure regulating cam 23 can make the continuously variable transmission 1 function as a one-way clutch.

A thrust bearing 25 is provided between the first cam member 231 of the pressure adjusting cam 23 and the housing 72 described later. For the thrust bearing 25, for example, a needle bearing is used. The first cam member 231 and the housing 72 can rotate relative to each other via the thrust bearing 25. As a result, the input rotating body 20 and the output rotating body 70 can be rotated at different rotation speeds.

The plurality of planetary rollers 30 are arranged around the main shaft 9. Each planet roller 30 is rotatably supported around a swingable rotation axis 300. As shown in FIGS. 2 to 4, the surface of each planet roller 30 has a first inclined surface 301, a second inclined surface 302, and an annular recess 303. The first inclined surface 301 is a hemispherical (spherical) surface centered on the vicinity of the center of the rotation axis 300, which gradually increases in diameter as the distance from one end of the rotation axis 300 increases. The first inclined surface 301 comes into contact with the second cam member 232. The second inclined surface 302 is a conical surface whose diameter gradually increases as the distance from the other end of the rotation shaft 300 increases. The second inclined surface 302 comes into contact with the contact member 71 of the output rotating body 70, which will be described later.

The annular recess 303 is an annular groove centered on the rotation shaft 300. The annular recess 303 is located between the first inclined surface 301 and the second inclined surface 302. As shown in FIGS. 2 to 4, the shape of the annular recess 303 is substantially arcuate in the cross section including the main shaft 9. An annular convex portion 51 of the movable ring 50, which will be described later, comes into contact with the annular recess 303.

In this way, the planet roller 30 is in contact with the input rotating body 20, the output rotating body 70, and the movable ring 50, and is supported by these three contact points.

FIG. 7 is an exploded cross-sectional view of the planet roller 30. As shown in FIG. 7, the planet roller 30 of the present embodiment is formed by combining the first planet member 31 and the second planet member 32 in the axial direction. The first planetary member 31 is a hemispherical member having a first inclined surface 301. The second planet member 32 is a conical member having a second inclined surface 302 and an annular recess 303. When the first planet member 31 and the second planet member 32 are combined, for example, the cylindrical protrusion 304 provided on the second planet member 32 is press-fitted into the first planet member 31. However, the method of fixing the first planet member 31 and the second planet member 32 may be another method such as welding.

The planet roller 30 preferably has a cavity 33 inside for weight reduction. If the structure is such that the first planet member 31 and the second planet member 32 are combined as in the present embodiment, the planet roller 30 having the cavity 33 inside can be easily formed.

Further, in the present embodiment, the entire annular recess 303 belongs to the second planet member 32. That is, the annular recess 303 is not divided into two members. By doing so, it is possible to prevent the formation of a minute step on the surface of the annular recess 303. That is, the dimensional accuracy of the annular recess 303 can be improved. In addition, the rigidity of the annular recess 303 can be increased. Therefore, the annular convex portion 51 of the movable ring 50, which will be described later, can be brought into contact with the annular concave portion 303 with high accuracy. The annular recess 303 may belong to the first planetary member 31.

The guide member 40 includes a first guide plate 41 and a second guide plate 42. The first guide plate 41 and the second guide plate 42 are disc-shaped members fixed to the hollow shaft 10. The first guide plate 41 and the second guide plate 42 cannot rotate relative to the hollow shaft 10. As shown in FIGS. 2 to 4, the first guide plate 41 and the second guide plate 42 are located on both sides of the planet roller 30 in the axial direction. Further, the first guide plate 41 and the second guide plate 42 each expand radially outward with respect to the main shaft 9.

The first guide plate 41 is provided with a plurality of first notches 410 at equal intervals in the circumferential direction. Each first notch 410 is recessed inward in the radial direction from the outer peripheral portion of the first guide plate 41. The second guide plate 42 is provided with a plurality of second notches 420 at equal intervals in the circumferential direction. Each of the second notches 420 is recessed inward in the radial direction from the outer peripheral portion of the second guide plate 42. One end of the rotation axis 300 of the planetary roller 30 fits into the first notch 410. The other end of the rotation shaft 300 of the planetary roller 30 fits into the second notch 420. As a result, the positions of both ends of the rotation shaft 300 of the planetary roller 30 in the circumferential direction are limited.

One end of the rotation shaft 300 can be displaced in the radial direction along the first notch 410. Further, the other end of the rotation shaft 300 can be displaced in the radial direction along the second notch 420. As will be described later, both ends of the rotation shaft 300 are displaced in the radial direction according to the axial position of the movable ring 50. As a result, the inclination angle of the rotation shaft 300 in the cross section including the main shaft 9 changes. The inclination of the rotation shaft 300 of the planetary roller 30 with respect to the main shaft 9 due to the displacement of the positions of both ends of the rotation shaft 300 in the radial direction is hereinafter referred to as "inclination in the radial direction". ..

The movable ring 50 is an annular member located on the radial outside of the hollow shaft 10 and on the radial inside of the planetary roller 30. The movable ring 50 has an annular convex portion 51 that projects outward in the radial direction. As shown in FIGS. 2 to 4, the shape of the annular convex portion 51 is substantially arcuate in the cross section including the main shaft 9. The annular convex portion 51 fits into the annular concave portion 303 of the planet roller 30. As a result, the movable ring 50 and the planet roller 30 are engaged with each other.

The movable ring 50 is supported by the hollow shaft 10 via the engaging member 81 and the second bearing 82. For the second bearing 82, for example, a ball bearing is used. The movable ring 50 is fixed to the outer ring of the second bearing 82. Therefore, the movable ring 50 can rotate relative to the hollow shaft 10 and the engaging member 81 around the main shaft 9.

Further, as shown in FIGS. 2 to 4, the hollow shaft 10 has a slit 11 extending in the axial direction. The engaging member 81 is fixed to the inner ring of the second bearing 82 and engages with the slit 11 so as to be slidable in the axial direction. Therefore, the engaging member 81, the second bearing 82, and the movable ring 50 can be integrally moved in the axial direction along the slit 11.

The operation unit 60 is a mechanism for switching the axial position of the movable ring 50. As shown in FIGS. 2 to 4, the operation unit 60 includes a rod 61 and a wire mechanism 62. The rod 61 is a columnar member inserted inside the hollow shaft 10. The rod 61 extends axially along the spindle 9. The wire mechanism 62 is connected to one end of the rod 61. The engaging member 81 is fixed to the other end of the rod 61. The user of the bicycle 100 can change the axial position of the rod 61 by operating the wire mechanism 62. When the rod 61 moves in the axial direction, the engaging member 81, the second bearing 82, and the movable ring 50 also move in the axial direction along the slit 11. Then, as the movable ring 50 moves in the axial direction, the engagement position between the annular convex portion 51 and the annular concave portion 303 also changes in the axial direction. As a result, the radial inclination angle of the planetary roller 30 changes.

However, the operation unit 60 may be realized by another mechanism such as a screw that can be positioned in the axial direction.

The output rotating body 70 rotates around the spindle 9 at the rotation speed after shifting. Hereinafter, the rotation speed after shifting is referred to as a "second rotation speed". As shown in FIGS. 2 to 4, the output rotating body 70 of this embodiment has a contact member 71 and a housing 72. The contact member 71 is an annular member centered on the spindle 9. The contact member 71 comes into contact with the second inclined surface 302 of the planet roller 30. The housing 72 is an annular housing that internally houses the pressure adjusting cam 23, the plurality of planet rollers 30, the guide member 40, and the movable ring 50. The housing 72 is supported by the hollow shaft 10 via a third bearing 73. Further, the housing 72 is supported by the relay member 22 via the fourth bearing 74.

The contact member 71 and the housing 72 are fixed to each other so as not to rotate relative to each other. Therefore, when the contact member 71 rotates with the rotation of the planet roller 30, the housing 72 and the contact member 71 also rotate at the second rotation speed around the main shaft 9. Further, the housing 72 is fixed to a hub provided in the center of the wheel 121 of the rear wheel 120 of the bicycle 100. Therefore, as the housing 72 rotates, the rear wheel 120 of the bicycle 100 also rotates at the second rotation speed.

<3. About shifting operation>
Subsequently, the shifting operation of the continuously variable transmission 1 described above will be described.

When the input rotating body 20 rotates at the first rotation speed by the power obtained from the roller chain 140, the second cam member 232 of the pressure adjusting cam 23 also comes into contact with the first inclined surface 301 of the planetary roller 30, and the first It rotates at the number of revolutions. Then, the planetary roller 30 rotates about the rotation axis 300 due to the frictional force between the second cam member 232 and the first inclined surface 301. Further, the output rotating body 70 rotates at the second rotation speed due to the frictional force between the second inclined surface 302 and the contact member 71.

Here, as described above, in the present embodiment, the user of the bicycle 100 can change the radial inclination angle of the planetary roller 30 by operating the operation unit 60.

For example, as shown in FIG. 3, when the planetary roller 30 is inclined in the radial direction so that one end of the rotation shaft 300 approaches the main shaft 9, the rotation of the portion of the first inclined surface 301 that comes into contact with the input rotating body 20. The distance from the shaft 300 increases. Then, the distance from the rotation shaft 300 of the portion of the second inclined surface 302 that comes into contact with the output rotating body 70 becomes smaller. Therefore, the second rotation speed, which is the rotation speed of the output rotating body 70, is smaller than the first rotation speed, which is the rotation speed of the input rotating body 20. That is, the rotational movement of the input rotating body 20 is decelerated, and the output rotating body 70 outputs the output to the rear wheels 120.

On the other hand, as shown in FIG. 4, when the planetary roller 30 is inclined in the radial direction so that one end of the rotation shaft 300 is away from the main shaft 9, the rotation of the portion of the first inclined surface 301 that comes into contact with the input rotating body 20. The distance from the shaft 300 becomes smaller. Then, the distance from the rotation shaft 300 of the portion of the second inclined surface 302 that comes into contact with the output rotating body 70 becomes large. Therefore, the second rotation speed, which is the rotation speed of the output rotating body 70, is larger than the first rotation speed, which is the rotation speed of the input rotating body 20. That is, the rotational movement of the input rotating body 20 is accelerated, and the output rotating body 70 outputs the output to the rear wheels 120.

As described above, in the continuously variable transmission 1 of the present embodiment, the inclination angle in the cross section including the main shaft 9 of the rotating shaft 300 of the planetary roller 30 changes according to the axial position of the movable ring 50. Then, the contact position of the first inclined surface 301 with respect to the input rotating body 20 and the contact position of the second inclined surface 302 with respect to the output rotating body 70 change, respectively. As a result, the gear ratio between the input rotating body 20 and the output rotating body 70 can be switched.

8 to 10 show the pressure F1 generated at the contact point between the second cam member 232 and the first inclined surface 301, and the pressure F2 generated at the contact point between the contact member 71 and the second inclined surface 302. Is. FIG. 8 shows a state at a constant speed, FIG. 9 shows a state at a deceleration, and FIG. 10 shows a state at a speed increase.

The first inclined surface 301 has a spherical shape. Therefore, the inclination angle of the first inclined surface 301 at the contact point between the second cam member 232 and the first inclined surface 301 is constant regardless of the inclination angle in the radial direction of the planet roller 30. Therefore, the direction of the pressure F1 generated at the contact point is also constant regardless of the radial inclination angle of the planetary roller 30. Therefore, if the torque input to the input rotating body 20 is constant, the pressure generated at the contact point at the time of constant speed, deceleration, and speed increase, as shown in FIGS. 8 to 10. The size of F1 does not change.

If the pressure F1 becomes too small, slippage is likely to occur between the second cam member 232 and the first inclined surface 301. Further, when the pressure F1 becomes excessive, rolling resistance more than necessary occurs between the second cam member 232 and the first inclined surface 301, and the power transmission efficiency tends to decrease. Further, when the pressure F1 becomes excessive, the second cam member 232 or the first inclined surface 301 is likely to be damaged. As in the present embodiment, if the pressure F1 is constant regardless of the radial inclination angle of the planetary roller 30, these problems can be solved.

The shape of the first inclined surface 301 does not have to be exactly along a true sphere. That is, the "spherical shape" in the present invention also includes a substantially spherical shape. Further, the direction and magnitude of the pressure F1 generated at the contact point between the second cam member 232 and the first inclined surface 301 do not have to be completely constant. Since the first inclined surface 301 is "spherical", it is sufficient that the change in the direction and magnitude of the pressure F1 generated at the contact point can be suppressed.

On the other hand, the second inclined surface 302 has a conical shape. Therefore, as shown in FIGS. 8 to 10, the inclination angle of the second inclined surface 302 at the contact point between the contact member 71 and the second inclined surface 302 changes according to the radial inclination angle of the planet roller 30. .. Therefore, the direction of the pressure F2 generated at the contact point also changes according to the radial inclination angle of the planetary roller 30. Therefore, as shown in FIG. 9, the pressure F2 at the time of deceleration becomes larger than the pressure F2 at the time of constant velocity. Further, as shown in FIG. 10, the pressure F2 at the time of increasing the speed is smaller than the pressure F2 at the time of constant speed.

In this way, the pressure F2 corresponding to the gear ratio can be generated at the contact point between the contact member 71 and the second inclined surface 302.

As shown in FIGS. 8 to 10, the conical second inclined surface 302 receives a larger pressure as it is closer to its apex. Therefore, in the present embodiment, as shown in FIG. 7, the conical second planet member 32 is made thicker toward the apex. That is, the thickness of the second planet member 32 in the axial direction or the radial direction is increased toward the apex. In this way, it is possible to prevent the second planet member 32 from being deformed by a load during use. On the other hand, the spherical first inclined surface 301 receives a constant pressure regardless of its contact position. Therefore, in the present embodiment, as shown in FIG. 7, the thickness of the hemispherical first planet member 31 in the axial direction or the radial direction is made constant thin.

<4. Modification example>
Although the exemplary embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.

<4-1. First modification>
FIG. 11 is a diagram showing a planetary roller 30A and a movable ring 50A according to the first modification. In the example of FIG. 11, the axial width d1 of the annular recess 303A of the planet roller 30A is larger than the axial width d2 of the annular convex portion 51A provided on the outer peripheral portion of the movable ring 50. Then, in the cross section including the main shaft, the radius of curvature of the annular recess 303A is larger than the radius of curvature of the annular convex portion 51A. In this way, the contact between the planetary roller 30A and the movable ring 50A is per point, and the rolling resistance is reduced. Further, the corners located at both ends of the annular recess 303A in the axial direction do not hit the movable ring 50A. Therefore, the contact resistance between the planetary roller 30A and the movable ring 50A can be reduced.

<4-2. Second modification>
FIG. 12 is a vertical sectional view of the continuously variable transmission 1B according to the second modification. In the example of FIG. 12, the coil spring 90B is provided inside the hollow shaft 10B. The coil spring 90B is an elastic member that can expand and contract in the axial direction. The free end, which is one end of the coil spring 90B in the axial direction, comes into contact with the engaging member 81B. Further, a positioning member 12B is arranged inside the hollow shaft 10B. The fixed end, which is the other end of the coil spring 90B in the axial direction, comes into contact with the positioning member 12B. In this way, the coil spring 90B is arranged between the positioning member 12B and the engaging member 81B in a state of being compressed more than the natural length. Therefore, the coil spring 90B constantly pressurizes the engaging member 81B, the second bearing 82B, and the movable ring 50B in a direction away from the positioning member 12B in the axial direction. That is, the coil spring 90B always applies an urging force toward one end side in the axial direction to the engaging member 81B, the second bearing 82B, and the movable ring 50B.

FIG. 13 is a plan view of the first guide plate 41B and the second guide plate 42B according to the second modification as viewed from one side of the spindle 9B. FIG. 14 is a view of the planet roller 30B according to the second modification as viewed from the outside in the radial direction. Also in this modification, the first guide plate 41B has a plurality of first notches 410B. Further, the second guide plate 42B has a plurality of second notches 420B. However, as shown in FIGS. 13 and 14, in this modified example, the position of the first notch 410B in the circumferential direction with respect to the spindle 9B and the position of the second notch 420B in the circumferential direction with respect to the spindle 9B are slightly different. It's different. Therefore, as shown in FIG. 14, both ends of the rotation shaft 300B are held at different positions in the circumferential direction by the first guide plate 41B and the second guide plate 42B. The state in which the positions of both ends of the rotation shaft 300B in the circumferential direction are different in this way is hereinafter referred to as "a state of being inclined in the circumferential direction". The planet roller 30B is always supported in a state of being inclined in the circumferential direction.

When the input rotating body 20B rotates at the first rotation speed by the power obtained from the roller chain, the second cam member 232B of the pressure adjusting cam 23B also makes the first rotation while contacting the first inclined surface 301B of the planetary roller 30B. Rotate by number. Then, the planetary roller 30B rotates about the rotation shaft 300B due to the frictional force between the second cam member 232B and the first inclined surface 301B. Further, the output rotating body 70B rotates at the second rotation speed due to the frictional force between the second inclined surface 302B and the contact member 71B. At this time, as shown by an arrow in FIG. 14, the second inclined surface 302B of the planetary roller 30B applies a force Fo in the tangential direction proportional to the torque to the contact member 71B.

Here, the planet roller 30B is supported in a state of being inclined in the circumferential direction as described above. Therefore, the force Fo generates a component force Fa in the circumferential direction centered on the rotation axis 300B and a component force Fb in the direction parallel to the rotation axis 300B. Assuming that the inclination angle of the planetary roller 30B in the circumferential direction is θ, the relationship between the component force Fa and the component force Fb satisfies Fb = Fa · tan θ. When a component force Fb in a direction parallel to the rotation axis 300B is applied to the contact member 71B, the planetary roller 30B receives a reaction force Fc having the same magnitude as the component force Fb from the contact member 71. This reaction force Fc is a force that tends to incline the rotation shaft 300B in the radial direction so that one end (the end on the input rotating body 20B side) of the rotation shaft 300B of the planet roller 30B approaches the main shaft 9B.

On the other hand, the coil spring 90B pressurizes the engaging member 81B, the second bearing 82B, and the movable ring 50B in a direction away from the positioning member 12B in the axial direction. Therefore, as shown in FIG. 12, the planet roller 30B receives an axial force Fd from the movable ring 50B. This force Fd is a force that tends to incline the rotation shaft 300B in the radial direction so that one end of the planet roller 30B is separated from the main shaft 9B. Further, as one end of the rotation shaft 300B of the planetary roller 30B inclines toward the main shaft 9B, the coil spring 90B is compressed, so that the force Fd increases.

In this way, when the input rotating body 20B is loaded, two forces Fc and Fd that try to incline the rotation shaft 300B in the opposite directions in the radial direction are applied to the planet roller 30B. The rotation shaft 300B rests at an inclination angle in which these forces Fc and Fd are balanced. Then, the planet roller 30B rotates about the rotation axis 300B at the inclination angle.

For example, when the load is large (when the force Fo is strong), the component force Fb of the force Fo also becomes large. Therefore, the reaction force Fc of the component force Fb also increases. Therefore, the planet roller 30B is inclined in the radial direction so that one end of the rotation shaft 300B approaches the main shaft 9B. In that case, the rotational motion of the input rotating body 20B is decelerated, and the output rotating body 70B outputs the output to the rear wheels. On the other hand, when the load is small (when the force Fo is weak), the component force Fb of the force Fo also becomes small. Therefore, the reaction force Fc of the component force Fb also becomes small. Therefore, the planet roller 30B is inclined in the radial direction so that one end of the rotation shaft 300B is away from the main shaft 9B. In that case, the rotational motion of the input rotating body 20B is accelerated, and the output rotating body 70B outputs the output to the rear wheels.

As described above, in the continuously variable transmission 1B of FIG. 12, the radial inclination angle of the rotation shaft 300B of the planet roller 30B changes according to the load applied to the planet roller 30B. Therefore, the gear ratio between the input rotating body 20B and the output rotating body 70B can be automatically switched according to the load.

In the example of FIG. 12, the positioning member 12B is fixed to the other end of the rod 61B. Therefore, the user of the bicycle can adjust the axial positions of the rod 61 and the positioning member 12B by operating the operation unit 60B. When the axial position of the positioning member 12B changes, the position of the fixed end of the coil spring 90B also changes. Then, the pressure applied from the coil spring 90B to the engaging member 81B, the second bearing 82B, and the movable ring 50B changes. That is, the above-mentioned Fd changes. Therefore, the relationship between the load and the gear ratio can be adjusted.

For example, if the axial position of the positioning member 12B is changed in the direction approaching the input rotating body 20B, the above-mentioned force Fd becomes large. Therefore, it becomes easy to accelerate the rotational movement of the input rotating body 20B. On the other hand, when the axial position of the positioning member 12B is changed in the direction away from the input rotating body 20B, the above-mentioned force Fd becomes smaller. Therefore, it becomes easy to decelerate the rotational movement of the input rotating body 20B.

<4-3. Third variant>
FIG. 15 is a vertical sectional view of the continuously variable transmission 1C according to the third modification. The continuously variable transmission 1C of FIG. 15 has a solid input shaft 10C instead of the hollow shaft 10 of the above embodiment. Then, the first cam member 231C of the pressure adjusting cam 23C is fixed to the input shaft 10C without using a relay member. Further, the second cam member 232C of the pressure adjusting cam 23C comes into contact with the first inclined surface 301C of the planet roller 30C on the inner side in the radial direction from the rotation shaft 300C.

Further, in the example of FIG. 15, the output rotating body 70C has a contact member 71C and an output shaft 73C. The contact member 71C comes into contact with the second inclined surface 302C of the planetary roller 30C on the inner side in the radial direction from the rotation shaft 300C. The output shaft 73C extends along the spindle 9C. The contact member 71C and the output shaft 73C are fixed to each other so as not to rotate relative to each other.

Further, in the example of FIG. 15, the movable ring 50C and the operation unit 60C are located radially outside the planet roller 30C. The movable ring 50C has an annular convex portion 51C that projects inward in the radial direction. The annular convex portion 51C fits into the annular recess 303C of the planet roller 30C. As a result, the movable ring 50C and the planet roller 30C are engaged with each other. Further, the movable ring 50C is supported by the engaging member 81C so as to be slidable in the circumferential direction. Further, the movable ring 50C and the engaging member 81C can move in the axial direction along a guide portion (not shown). The user can switch the axial position of the movable ring 50C by operating the operation unit 60C connected to the engaging member 81C.

<4-4. Other variants>
In the above embodiment, the pressure adjusting cam is provided only on the input rotating body among the input rotating body and the output rotating body. However, the output rotating body may also be provided with a pressure adjusting cam.

Further, in the above embodiment, the planet roller has an annular recess, and the movable ring has an annular protrusion that fits into the annular recess. However, the planetary roller may have an annular protrusion and the movable ring may have an annular recess. Then, the annular concave portion of the movable ring may be fitted with the annular convex portion of the planetary roller. In that case, if the planetary roller is formed of two members, it is preferable that the entire annular convex portion belongs to one of the two members.

Further, in the above embodiment, the continuously variable transmission for a bicycle has been described. However, a continuously variable transmission having an equivalent structure may be used for applications other than bicycles. For example, a continuously variable transmission having an equivalent structure may be mounted on a tricycle, a wheelchair, a trolley, an automatic guided vehicle, a robot, or the like.

Further, the shape of the details of the continuously variable transmission and the bicycle may be different from the shape shown in each figure of the present application. In addition, the elements appearing in the above-described embodiments and modifications may be appropriately combined as long as there is no inconsistency.

This application claims the priority based on Japanese Patent Application No. 2017-210368, which is a Japanese application filed on October 31, 2017, and incorporates all the contents described in the Japanese application.

The present invention can be used for continuously variable transmissions and bicycles.

1,1B, 1C Continuously variable transmission 9,9B, 9C Main shaft 10,10B Hollow shaft 20,20B Input rotating body 21 Sprocket 22 Relay member 23, 23B, 23C Pressure regulating cam 23a 1st cam surface 23b 2nd cam surface 30 , 30A, 30B, 30C Planetary roller 31 1st planetary member 32 2nd planetary member 33 Cavity 40 Guide member 41, 41B 1st guide plate 42, 42B 2nd guide plate 50, 50A, 50B, 50C Movable ring 51, 51A, 51C annular convex part 60, 60B, 60C Operation part 70, 70B, 70C Output rotating body 71, 71B, 71C Contact member 72 Housing 81, 81B, 81C Engagement member 90B Coil spring 100 Bicycle 110 Front wheel 120 Rear wheel 121 Wheel 130 Pedal 140 Roller chain 231,231C 1st cam member 232,232B, 232C 2nd cam member 233 Rolling element 300, 300B, 300C Rotating shaft 301, 301B, 301C 1st inclined surface 302, 302B, 302C 2nd inclined surface 303, 303A , 303C Annular recess 410,410B 1st notch 420,420B 2nd notch

Claims (19)

It ’s a continuously variable transmission.
An input rotating body that rotates around the spindle at the number of revolutions before shifting,
An output rotating body that rotates at the number of rotations after shifting around the spindle, and
A plurality of planetary rollers arranged around the main axis and capable of rotating around the rotation axis,
A guide member that limits the positions of both ends of the rotation axis, and
An annular movable ring that can rotate around the main shaft and can move in the axial direction,
With
The planet roller
A spherical first inclined surface in contact with the input rotating body and
A conical second inclined surface in contact with the output rotating body and
An annular recess or an annular protrusion that engages with the movable ring,
Have,
A continuously variable transmission in which both ends of the rotating shaft are held by the guide member so as to be displaceable in the radial direction with respect to the main shaft. The continuously variable transmission according to claim 1.
A continuously variable transmission further provided with an operation unit for switching the axial position of the movable ring. The continuously variable transmission according to claim 1.
An elastic member that gives an axial urging force to the movable ring is further provided.
The guide member is a continuously variable transmission that holds both ends of the rotation shaft at different positions in the circumferential direction. The continuously variable transmission according to any one of claims 1 to 3.
The movable ring is a continuously variable transmission located inside the planet roller in the radial direction. The continuously variable transmission according to any one of claims 1 to 3.
The movable ring is a continuously variable transmission located on the radial outer side of the planetary roller. The continuously variable transmission according to any one of claims 1 to 5.
Further provided with a shaft extending along the spindle
A continuously variable transmission in which the input rotating body, the output rotating body, and the movable ring are supported by the shaft via bearings, respectively. The continuously variable transmission according to claim 6.
The guide member
A first guide plate fixed to the shaft and having a first notch into which one end of the rotation axis of the planetary roller is fitted.
A second guide plate fixed to the shaft and having a second notch into which the other end of the rotating shaft of the planetary roller fits.
Continuously variable transmission with. The continuously variable transmission according to any one of claims 1 to 7.
The annular concave portion or the annular convex portion is a continuously variable transmission located between the first inclined surface and the second inclined surface. The continuously variable transmission according to any one of claims 1 to 8.
The planet roller has the annular recess and
A continuously variable transmission in which the outer peripheral portion of the movable ring comes into contact with the surface of the planet roller that constitutes the annular recess. The continuously variable transmission according to claim 9.
A continuously variable transmission in which the radius of curvature of the annular recess is larger than the radius of curvature of the outer peripheral portion of the movable ring in the cross section including the spindle. The continuously variable transmission according to any one of claims 1 to 10.
The input rotating body is
A continuously variable transmission including a pressure adjusting cam that generates an axial pressing force on the planetary roller according to a load in the rotational direction. The continuously variable transmission according to claim 11.
The pressure adjusting cam
A pair of annular cam members arranged in the axial direction,
A rolling element interposed between the pair of cam members and
Have,
Each of the pair of cam members
When the input rotating body rotates in one direction, the first cam surface that comes into contact with the rolling body and
When the input rotating body rotates in the other direction, the second cam surface that comes into contact with the rolling element and
Have,
A continuously variable transmission in which the angle of the first cam surface with respect to the circumferential direction is smaller than the angle of the second cam surface with respect to the circumferential direction. The continuously variable transmission according to claim 12.
The angle of the first cam surface with respect to the circumferential direction is 3 ° or more and 35 ° or less.
A continuously variable transmission in which the angle of the second cam surface with respect to the circumferential direction is 70 ° or more and less than 90 °. The continuously variable transmission according to any one of claims 1 to 13.
The planetary roller is a continuously variable transmission having a cavity inside. The continuously variable transmission according to claim 14.
The planet roller
The first planetary member having the first inclined surface and
With the second planet member having the second inclined surface,
Continuously variable transmission with. The continuously variable transmission according to claim 15.
The first planetary member has a constant axial or radial thickness.
The second planetary member is a continuously variable transmission in which the thickness in the axial direction or the radial direction increases toward the apex of the second planetary member. The continuously variable transmission according to claim 15 or 16.
A continuously variable transmission in which the annular concave portion or the entire annular convex portion belongs to either the first planetary member or the second planetary member. The continuously variable transmission according to any one of claims 1 to 17.
A continuously variable transmission used for bicycles. A bicycle using the continuously variable transmission according to claim 18.

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