JP6380165B2 - Traction drive device - Google Patents

Description

  The present invention relates to a traction drive device including a ring roller, a sun roller, and a planetary roller.

  Conventionally, as a traction drive device provided with a ring roller, a sun roller, and a planetary roller, for example, there is a friction roller type speed reducer disclosed in Patent Document 1 shown below.

  The friction roller type speed reducer includes an annular roller, a sun roller, and an intermediate roller. Here, the annular roller, the sun roller, and the intermediate roller correspond to a ring roller, a sun roller, and a planetary roller.

  On the inner peripheral surface of the annular roller, the outer peripheral surface of the sun roller, and the outer peripheral surface of the intermediate roller, contact surfaces composed of inclined surfaces are formed. The sun roller is disposed inside the annular roller. The intermediate roller is disposed between the annular roller and the sun roller, and is in pressure contact with the annular roller and the sun roller with the contact surface in contact with the contact surfaces of the annular roller and the sun roller. The friction roller speed reducer transmits power through an oil film formed between the contact surface of the sun roller and the contact surface of the intermediate roller and between the contact surface of the intermediate roller and the contact surface of the annular roller.

JP 2012-193792 A

  By the way, in the friction roller type speed reducer described above, the contact surface pressure between the annular roller and the intermediate roller is smaller than the contact surface pressure between the intermediate roller and the sun roller. In order to set these contact surface pressures to a minimum required contact surface pressure, the contact surface pressures of the smaller annular roller and the intermediate roller must be set to a minimum required contact surface pressure. In this case, an excessive contact surface pressure is applied to the intermediate roller and the sun roller. As a result, the wear of the contact surfaces of the intermediate roller and the sun roller increases and the service life decreases.

  The present invention has been made in view of such circumstances, and provides a traction drive device that can suppress the difference between the contact surface pressure of the ring roller and the planetary roller and the contact surface pressure of the planetary roller and the sun roller. Objective.

The present invention, which has been made to solve the above problems, includes a ring roller, a sun roller disposed inside the ring roller, and a planetary roller that is in pressure contact with the ring roller and is in pressure contact with the sun roller. In a traction drive device that transmits power via an oil film formed between rollers and between a planetary roller and a ring roller, the difference between the contact surface pressure of the ring roller and the planetary roller and the contact surface pressure of the planetary roller and the sun roller is reduced. Further, the radius of curvature of the contact surface of the planetary roller pressed against the ring roller in the axial cross section of the planetary roller and the radius of curvature of the contact surface of the planetary roller pressed against the sun roller in the axial cross section of the planetary roller are adjusted. It is characterized by.

It has been found that the contact surface pressure can be adjusted by adjusting the radius of curvature of the roller contact surface in the axial section of the roller. According to this configuration, the axial cross section of the planetary roller on the contact surface of the planetary roller pressed against the ring roller so that the difference between the contact surface pressure of the ring roller and the planetary roller and the contact surface pressure of the planetary roller and the sun roller is reduced. And the radius of curvature of the contact surface in the axial cross section of the planetary roller of the contact surface of the planetary roller pressed against the sun roller are adjusted. Therefore, the difference between the contact surface pressure of the ring roller and the planetary roller and the contact surface pressure of the planetary roller and the sun roller can be suppressed.

It is an axial direction sectional view of the traction drive device in a reference form . FIG. 2 is an enlarged axial sectional view of a contact portion between a ring roller and a planetary roller in FIG. 1. FIG. 2 is an enlarged axial sectional view of a contact portion between a planetary roller and a sun roller in FIG. 1. It is a graph which shows the relationship between distance ratio x and reduction ratio z. It is a graph which shows the relationship between the transmission torque and contact surface pressure in the case of curvature radius R1 = curvature radius R2. It is a graph which shows the relationship between the transmission torque in the case of curvature radius R1 <curvature radius R2, and contact surface pressure. It is an axial sectional view of the traction drive device in an embodiment . FIG. 8 is an enlarged axial sectional view of a contact portion between a ring roller and a planetary roller in FIG. 7. FIG. 8 is an enlarged axial sectional view of a contact portion between a planetary roller and a sun roller in FIG. 7. It is a graph which shows the relationship between the transmission torque and contact surface pressure in the case of curvature radius R3 = curvature radius R4. It is a graph which shows the relationship between the transmission torque in the case of curvature radius R3> curvature radius R4, and contact surface pressure. It is an axial sectional view enlarged of the contact portion of the ring roller and the planetary roller in the variation of the embodiment. It is an axial sectional view enlarged of the contact portion of the planetary roller and the sun roller in the variation of the embodiment.

Next, the present invention will be described in more detail with reference embodiments and embodiments .

( Reference form )
First, the configuration of a traction drive device according to a reference embodiment will be described with reference to FIGS.

  A traction drive device 1 shown in FIG. 1 is a device that is configured by pressing a plurality of rollers in a radial direction, and transmits power by decelerating through an oil film formed between the rollers. The traction drive device 1 includes a ring roller 10, a sun roller 11, a plurality of planetary rollers 12, and a carrier 13.

  The ring roller 10 is an annular member whose inner peripheral surface is pressed against the planetary roller 12. The ring roller 10 includes a first ring roller 100 and a second ring roller 101.

  The first ring roller 100 is an annular member whose inner peripheral surface is pressed against the input side portion of the planetary roller 12. As shown in FIG. 2, a contact surface 100 a that is pressed against the input side portion of the planetary roller 12 is formed on the inner peripheral surface of the first ring roller 100. The contact surface 100a is formed to have an arc shape with a radius of curvature R1 in the axial section of the first ring roller 100.

  As shown in FIG. 1, the second ring roller 101 is an annular member whose inner peripheral surface is pressed against the output side portion of the planetary roller 12. As shown in FIG. 2, a contact surface 101 a that is pressed against the output side portion of the planetary roller 12 is formed on the inner peripheral surface of the second ring roller 101. The contact surface 101a is formed to have an arc shape with a radius of curvature R1 in the axial section of the second ring roller 101. The second ring roller 101 is arranged side by side with the first ring roller 100 in the axial direction.

  The sun roller 11 shown in FIG. 1 is a substantially cylindrical member that is disposed inside the ring roller 10 and whose outer peripheral surface is pressed against the planetary roller 12. As shown in FIG. 3, contact surfaces 110 and 111 that are pressed against the planetary roller 12 are formed on the outer peripheral surface of the sun roller 11.

  The contact surface 110 is a portion that is pressed against the input side portion of the planetary roller 12. The contact surface 110 is formed to have an arc shape with a radius of curvature R <b> 2 in the axial section of the sun roller 11. The contact surface 111 is a portion that is pressed against the output side portion of the planetary roller 12. The contact surface 111 is formed to have an arc shape with a radius of curvature R <b> 2 in the axial cross section of the sun roller 11.

  The planetary roller 12 shown in FIG. 1 is arranged between the ring roller 10 and the sun roller 11 at equal intervals in the circumferential direction, and the outer peripheral surface thereof is pressed against the inner peripheral surface of the ring roller 10 and is also pressed against the outer peripheral surface of the sun roller 11. It is a cylindrical member. As shown in FIGS. 2 and 3, contact surfaces 120 and 121 that are in pressure contact with the first ring roller 100, the second ring roller 101, and the sun roller 11 are formed on the outer peripheral surface of the planetary roller 12.

  The contact surface 120 is a portion that is formed on the input side portion and is in pressure contact with the contact surface 100 a of the first ring roller 100 and the contact surface 110 of the sun roller 11. The contact surface 120 is formed so as to incline linearly in the axial direction toward the input side in the axial section of the planetary roller 12. The contact surface 121 is a portion that is formed on the output side portion and is in pressure contact with the contact surface 101 a of the second ring roller 101 and the contact surface 111 of the sun roller 11. The contact surface 121 is formed so as to incline linearly in the axial direction toward the output side in the axial section of the planetary roller 12.

  In the planetary roller 12, the contact surface 120 contacts the contact surface 100a of the first ring roller 100 and the contact surface 110 of the sun roller 11, and the contact surface 121 contacts the contact surface 101a of the second ring roller 101 and the contact surface 111 of the sun roller 11, respectively. In this state, the first ring roller 100, the second ring roller 101, and the sun roller 11 are pressed against each other.

  The carrier 13 is a member that supports the planetary rollers 12 so as to be capable of rotating and revolving around the sun roller 11 while being arranged at equal intervals in the circumferential direction.

  By the way, the reduction ratio z of the traction drive device 1 is expressed by Expression (1).

z = xy + 1 (1)

  Here, the distance ratio x is a ratio L2 / L1 of the distance L2 to the distance L1 shown in FIG. The distance ratio y is a ratio L4 / L3 of the distance L4 to the distance L3. The distance L1 is a distance from the rotation center C1 of the planetary roller 12 to the contact points of the contact surfaces 120 and 121 of the planetary roller 12 that is pressed against the ring roller 10. The distance L2 is a distance from the rotation center C1 of the planetary roller 12 to the contact points of the contact surfaces 120 and 121 of the planetary roller 12 that is pressed against the sun roller 11. The distance L3 is a distance from the rotation center C2 of the sun roller 11 to the contact points of the contact surfaces 110 and 111 of the sun roller 11 that are pressed against the planetary roller 12. The distance L4 is a distance from the rotation center of the sun roller 11 to the contact points of the contact surfaces 120 and 121 of the planetary roller 12 that is pressed against the ring roller 10.

  When the distance ratio x = distance ratio y, the reduction ratio z of the traction drive device 1 is expressed by Expression (2).

z = x ² +1 (2)

  As shown in FIG. 4, the curve of the expression (2) shows a reduction ratio z that can be configured when the distance ratio x = the distance ratio y. On the other hand, the region 1 on the upper left side of the curve of the equation (2) has a reduction ratio z that can be configured when the distance ratio x <the distance ratio y, and the region 2 on the lower right side of the curve of the equation (2) The reduction ratio z that can be configured when the distance ratio x> distance ratio y is shown.

  On the other hand, when the distance ratio y = 1, the reduction ratio z of the traction drive device 1 is expressed by Expression (3).

z = x + 1 (3)

  However, when the distance ratio y = 1, the distances L3 and L4 shown in FIG. 1 are the distance L3 = the distance L4, and the traction drive device is not established in the first place. Therefore, the region below the straight line of the formula (3) may be excluded. Further, when the reduction ratio z <2, the traction drive device is not established. Therefore, this region may also be excluded.

  In the traction drive device 1, the distance ratios x1 and y are such that the distance ratio x <distance ratio y, and the speed reduction ratio z is set to a predetermined value in the region 1 shown in FIG. . The curvature radii R1 and R2 shown in FIGS. 2 and 3 are set to different values so that the difference between the contact surface pressure between the ring roller 10 and the planetary roller 12 and the contact surface pressure between the planetary roller 12 and the sun roller 11 is reduced. ing. Specifically, the curvature radii R1 and R2 are set so that the curvature radius R1 <the curvature radius R2.

Next, the operation of the traction drive device according to the reference embodiment will be described with reference to FIGS. 1 to 3, 5, and 6.

  When torque is applied to the sun roller 11 shown in FIG. 1, the sun roller 11 rotates. When the sun roller 11 rotates, power is transmitted through an oil film formed between the contact surfaces 110 and 111 and the contact surfaces 120 and 121, and the planetary roller 12 rotates. When the planetary roller 12 rotates, power is transmitted through an oil film formed between the contact surfaces 120 and 121 and the contact surfaces 100a and 101a, and the planetary roller 12 rotates on the inside of the ring roller 10 while the sun roller 11 rotates. Revolve around. The carrier 13 rotates in synchronization with the revolution of the planetary roller 12. As a result, the power input to the sun roller 11 is output from the carrier 13 while being decelerated.

  By the way, the ring roller 10 and the planetary roller 1, and the planetary roller 12 and the sun roller 11 are pressed against each other. Therefore, contact surface pressure is applied to the contact surfaces 100 a and 101 a of the ring roller 10, the contact surfaces 120 and 121 of the planetary roller 12, and the contact surfaces 110 and 111 of the sun roller 11. When the distance ratio x, y is the distance ratio x <distance ratio y, the curvature radius R1 of the contact surfaces 100a, 101a and the curvature radius R2 of the contact surfaces 110, 111 shown in FIGS. 2 and 3 are the curvature radius R1 = the curvature. When the radius R2 (curvature radius R1, R2 = 150 mm) is set, the contact surface pressure between the ring roller 10 and the planetary roller 12 is changed to the contact surface between the planetary roller 12 and the sun roller 11 as shown in FIG. Less than pressure. In order to set these contact surface pressures to a minimum required contact surface pressure, the contact surface pressure between the smaller ring roller 10 and the planetary roller 12 must be set to a minimum required contact surface pressure. In this case, an excessive contact surface pressure is applied to the planetary roller 12 and the sun roller 11. However, in the traction drive device 1, the curvature radii R1 and R2 are set such that the curvature radius R1 <the curvature radius R2 (the curvature radius R1 = 150 mm, the curvature radius R2 = 180 mm). Therefore, as shown in FIG. 6, the contact surface pressure between the planetary roller 12 and the sun roller 11 is smaller than in the case shown in FIG. 5 where the radius of curvature R1 = the radius of curvature R2. As a result, the difference between the contact surface pressure between the ring roller 10 and the planetary roller 12 and the contact surface pressure between the planetary roller 12 and the sun roller 11 can be almost eliminated.

Next, effects of the traction drive device according to the reference embodiment will be described.

It has been found that the contact surface pressure can be adjusted by adjusting the radius of curvature of the roller contact surface constituting the traction drive device 1 in the axial section of the roller. According to the reference mode , the contact surface 100a of the ring roller 10 that is pressed against the planetary roller 12 so that the difference between the contact surface pressure of the ring roller 10 and the planetary roller 12 and the contact surface pressure of the planetary roller 12 and the sun roller 11 is reduced. , 101a, the curvature radius R1 in the axial section of the ring roller 10 and the curvature radius R2 in the axial section of the sun roller 11 of the contact surface 110, 111 of the sun roller 11 pressed against the planetary roller 12 are adjusted. Therefore, the difference between the contact surface pressure between the ring roller 10 and the planetary roller 12 and the contact surface pressure between the planetary roller 12 and the sun roller 11 can be suppressed. Therefore, increase in wear of the contact surface can be suppressed. Thereby, the lifetime reduction of the traction drive device 1 can be suppressed.

As shown in FIG. 5, when the radius of curvature R1 = the radius of curvature R2, a difference between the contact surface pressure between the ring roller 10 and the planetary roller 12 and the contact surface pressure between the planetary roller 12 and the sun roller 11 occurred. According to the reference mode , the radii of curvature R1 and R2 are set to be different from each other so that the difference between the contact surface pressure of the ring roller 10 and the planetary roller 12 and the contact surface pressure of the planetary roller 12 and the sun roller 11 is reduced. . Therefore, the difference between the contact surface pressure between the ring roller 10 and the planetary roller 12 and the contact surface pressure between the planetary roller 12 and the sun roller 11 can be reliably suppressed.

The distance from the rotation center C1 of the planetary roller 12 to the contact point of the contact surfaces 120 and 121 of the planetary roller 12 pressed against the ring roller 10 is L1, and the contact surface 120 of the planetary roller 12 pressed against the sun roller 11 from the rotation center C1. , 121 is the distance to the contact point L2, the distance from the rotation center C2 of the sun roller 11 to the contact point of the contact surface 110, 111 of the sun roller 11 pressed against the planetary roller 12 is L3, and the distance from the rotation center C2 to the ring roller 10 When the distance to the contact point of the contact surface 120, 121 of the planetary roller 12 to be pressed is L4, the ratio L2 / L1 of the distance L2 to the distance L1 is x, and the ratio L4 / L3 of the distance L4 to the distance L3 is y, the distance When the ratio x <distance ratio y, the radius of curvature R1 <the radius of curvature R2 is set so that the contact between the ring roller 10 and the planetary roller 12 And pressure was found to be suppressed difference in the contact surface pressure of the planetary rollers 12 and sun roller 11. According to the reference mode , the traction drive device 1 is configured such that the distance ratio x <the distance ratio y. The curvature radius R1 is set to be smaller than the curvature radius R2. Therefore, the difference between the contact surface pressure of the ring roller 10 and the planetary roller 12 and the contact surface pressure of the planetary roller 12 and the sun roller 11 can be more reliably suppressed.

In the reference embodiment , the contact surfaces 120 and 121 of the planetary roller 12 are formed so as to be linear in the axial cross section of the planetary roller 12, but the present invention is not limited to this. The contact surfaces 120 and 121 of the planetary roller 12 may be formed in an arc shape having a predetermined radius of curvature in the axial cross section of the planetary roller 12.

( Embodiment )
Next, the traction drive device of the embodiment will be described. Traction drive device embodiment differs from the traction drive device of Reference Embodiment, by changing the configuration of the planetary rollers, the distance L1 and the distance L2 are obtained by different.

First, FIG. 4, description will be given of a configuration of a traction drive device embodiment with reference to FIGS.

  The traction drive device 2 shown in FIG. 7 is configured by pressing a plurality of rollers in the radial direction, and transmits power by decelerating through an oil film formed between the rollers. The traction drive device 2 includes a ring roller 20, a sun roller 21, a plurality of planetary rollers 22, and a carrier 23.

  The ring roller 20 is an annular member whose inner peripheral surface is pressed against the planetary roller 22. The ring roller 20 includes a first ring roller 200 and a second ring roller 201.

  The first ring roller 200 is an annular member whose inner peripheral surface is pressed against the input side portion of the planetary roller 22. As shown in FIG. 8, a contact surface 200 a that is pressed against the input side portion of the planetary roller 22 is formed on the inner peripheral surface of the first ring roller 200. The contact surface 200a is formed so as to incline linearly in the axial direction toward the input side in the cross section in the axial direction of the first ring roller 200. The first ring roller 200 is disposed on the input side of the planetary roller 22.

  As shown in FIG. 7, the second ring roller 201 is an annular member whose inner peripheral surface is pressed against the output side portion of the planetary roller 22. As shown in FIG. 8, a contact surface 201 a that is pressed against the output side portion of the planetary roller 22 is formed on the inner peripheral surface of the second ring roller 201. The contact surface 201a is formed so as to incline linearly in the axial direction toward the output side in the axial section of the second ring roller 201. The second ring roller 201 is disposed on the output side of the planetary roller 22.

  The sun roller 21 shown in FIG. 7 is a substantially cylindrical member that is disposed inside the ring roller 20 and whose outer peripheral surface is pressed against the planetary roller 22. As shown in FIG. 9, contact surfaces 210 and 211 that are pressed against the planetary roller 22 are formed on the outer peripheral surface of the sun roller 21.

  The contact surface 210 is a portion that is pressed against the input side portion of the planetary roller 22. The contact surface 210 is formed so as to incline linearly toward the opposite axis side toward the input side in the axial cross section of the sun roller 21. The contact surface 211 is a part that is pressed against the output side portion of the planetary roller 22. The contact surface 211 is formed so as to incline linearly toward the output side toward the opposite axis in the axial section of the sun roller 21.

  The planetary rollers 22 shown in FIG. 7 are arranged at equal intervals in the circumferential direction between the ring roller 20 and the sun roller 21, and the outer peripheral surface thereof is pressed against the inner peripheral surface of the ring roller 20, and the outer peripheral surface of the sun roller 21 is It is a substantially cylindrical member that is press-contacted. The planetary roller 22 includes a large diameter portion 220 and small diameter portions 221 and 222.

  The large diameter part 220 is a cylindrical part. The small-diameter portion 221 is a cylindrical portion having a smaller diameter than the large-diameter portion 220 and is formed on the input side of the large-diameter portion 220 and the small-diameter portion 222 is formed on the output side of the large-diameter portion 220, respectively. As shown in FIGS. 8 and 9, contact surfaces 223 and 224 that are pressed against the first ring roller 200 and the second ring roller 201 are formed on the outer peripheral surfaces of the small diameter portions 221 and 222 of the planetary roller 22, respectively. Yes. Further, contact surfaces 225 and 226 that are pressed against the sun roller 21 are formed on the outer peripheral surface of the large-diameter portion 220 of the planetary roller 22.

  As shown in FIG. 8, the contact surface 223 is a portion formed on the small diameter portion 221 and pressed against the contact surface 200 a of the first ring roller 200. The contact surface 223 is formed in an arc shape having a radius of curvature R3 in the axial cross section of the planetary roller 22. The contact surface 224 is a part formed on the small diameter portion 222 and pressed against the contact surface 201 a of the second ring roller 201. The contact surface 224 is formed in an arc shape having a radius of curvature R3 in the axial cross section of the planetary roller 22.

  As shown in FIG. 9, the contact surface 225 is a portion formed on the input side portion of the large diameter portion 220 and pressed against the contact surface 210 of the sun roller 21. The contact surface 225 is formed to have an arc shape with a radius of curvature R4 in the axial cross section of the planetary roller 22. The contact surface 226 is a portion formed on the output side portion of the large diameter portion 220 and pressed against the contact surface 211 of the sun roller 21. The contact surface 226 is formed to have an arc shape with a radius of curvature R4 in the axial cross section of the planetary roller 22.

  As shown in FIGS. 8 and 9, the planetary roller 22 has the contact surface 223 as the contact surface 200a of the first ring roller 200, the contact surface 224 as the contact surface 201a of the second ring roller 201, and the contact surfaces 225, 226. In contact with the contact surfaces 210 and 211 of the sun roller 21, respectively, and is in pressure contact with the first ring roller 200, the second ring roller 201, and the sun roller 21.

  The carrier 23 is a member that arranges the planetary rollers 22 at equal intervals in the circumferential direction and supports the sun rollers 21 so that they can rotate and revolve around the sun rollers 21.

In the traction drive device 2, the distance ratios x1 and y4 are set such that the distance ratio x, y is the distance ratio x> distance ratio y, and the reduction ratio z is a predetermined value in the region 2 shown in FIG. . Here, the distance ratios x and y and the distances L1 to L4 correspond to the distance ratios x and y and the distances L1 to L4 in the reference form . The distance ratio x is a ratio L2 / L1 of the distance L2 to the distance L1 shown in FIG. The distance ratio y is a ratio L4 / L3 of the distance L4 to the distance L3. The distance L1 is a distance from the rotation center C1 of the planetary roller 22 to the contact points of the contact surfaces 223 and 224 of the planetary roller 22 that are pressed against the ring roller 20. The distance L2 is a distance from the rotation center C1 of the planetary roller 22 to the contact points of the contact surfaces 225 and 226 of the planetary roller 22 that are pressed against the sun roller 21. The distance L3 is a distance from the rotation center C2 of the sun roller 21 to the contact points of the contact surfaces 210 and 211 of the sun roller 21 that are pressed against the planetary roller 22. The distance L4 is a distance from the rotation center C2 of the sun roller 21 to the contact points of the contact surfaces 223 and 224 of the planetary roller 22 that is pressed against the ring roller 20. The traction drive device 2 has the curvature radii R3 and R4 shown in FIGS. 8 and 9 so that the difference between the contact surface pressure of the ring roller 20 and the planetary roller 22 and the contact surface pressure of the planetary roller 22 and the sun roller 21 is reduced. Are set to different values. Specifically, the curvature radii R3 and R3 are set so that the curvature radius R3> the curvature radius R4.

Next, the operation will be described traction drive device embodiment with reference to FIGS. 7-11. Since the power transmission operation is the same as that in the reference embodiment , the description thereof is omitted. The contact surface pressure of the roller will be described.

  When the distance ratio x, y is the distance ratio x> distance ratio y, the curvature radius R3 of the contact surfaces 223, 224 and the curvature radius R4 of the contact surfaces 225, 226 shown in FIGS. When the radius R4 (curvature radius R3, R4 = 380 mm) is set, the contact surface pressure between the planetary roller 22 and the sun roller 21 is changed to the contact surface between the ring roller 20 and the planetary roller 22 as shown in FIG. Less than pressure. In order to set these contact surface pressures to a minimum required contact surface pressure, the contact surface pressure between the smaller planetary roller 22 and the sun roller 21 must be set to a minimum required contact surface pressure. In this case, an excessive contact surface pressure is applied to the ring roller 20 and the planetary roller 22. However, in the traction drive device 2, the curvature radii R3 and R4 are set such that the curvature radius R3> the curvature radius R4 (the curvature radius R3 = 700 mm, the curvature radius R4 = 380 mm). Therefore, as shown in FIG. 11, the contact surface pressure between the ring roller 20 and the planetary roller 22 is smaller than in the case shown in FIG. 10 where the radius of curvature R3 = the radius of curvature R4. As a result, the difference between the contact surface pressure between the ring roller 20 and the planetary roller 22 and the contact surface pressure between the planetary roller 22 and the sun roller 21 can be almost eliminated.

Next, effects of the traction drive device of the embodiment will be described.

According to the embodiment , the contact surface 223 of the planetary roller 22 that is pressed against the ring roller 20 so that the difference between the contact surface pressure of the ring roller 20 and the planetary roller 22 and the contact surface pressure of the planetary roller 22 and the sun roller 21 is reduced. The curvature radius R3 in the axial section of the planetary roller 22 of 224 and the curvature radius R4 in the axial section of the planetary roller 22 on the contact surface 225, 226 of the planetary roller 22 pressed against the sun roller 21 are adjusted. Therefore, similarly to the reference embodiment , the difference between the contact surface pressure of the ring roller 20 and the planetary roller 22 and the contact surface pressure of the planetary roller 22 and the sun roller 21 can be suppressed.

As shown in FIG. 10, when the radius of curvature R3 = the radius of curvature R4, the difference between the contact surface pressure between the ring roller 20 and the planetary roller 22 and the contact surface pressure between the planetary roller 22 and the sun roller 21 occurred. According to the embodiment , the radii of curvature R3 and R4 are set to be different from each other so that the difference between the contact surface pressure of the ring roller 20 and the planetary roller 22 and the contact surface pressure of the planetary roller 22 and the sun roller 21 is reduced. . Therefore, the difference between the contact surface pressure of the ring roller 20 and the planetary roller 22 and the contact surface pressure of the planetary roller 22 and the sun roller 21 can be reliably suppressed.

The distance from the rotation center C1 of the planetary roller 22 to the contact point of the contact surfaces 223 and 224 of the planetary roller 22 pressed against the ring roller 20 is L1, and the contact surface 225 of the planetary roller 22 pressed against the sun roller 21 from the rotation center C1. 226, the distance from the rotation center C2 of the sun roller 21 to the contact point of the contact surface 210, 211 of the sun roller 21 pressed against the planetary roller 22, L3, and the distance from the rotation center C2 to the ring roller 20. When the distance to the contact point of the contact surfaces 223 and 224 of the planetary roller 22 to be pressed is L4, the ratio L2 / L1 of the distance L2 to the distance L1 is x, and the ratio L4 / L3 of the distance L4 to the distance L3 is y. When the ratio x> the distance ratio y, the radius of curvature R3> the radius of curvature R4 is set so that the contact between the ring roller 20 and the planetary roller 22 And pressure was found to be suppressed difference in the contact surface pressure of the planetary rollers 22 and sun roller 21. According to the embodiment , the traction drive device 2 is configured such that the distance ratio x> the distance ratio y. The curvature radius R3 is set to be greater than the curvature radius R4. Therefore, the difference between the contact surface pressure of the ring roller 20 and the planetary roller 22 and the contact surface pressure of the planetary roller 22 and the sun roller 21 can be reliably suppressed.

In the embodiment , the traction drive device 2 is configured such that the distance ratio x> distance ratio y and the radius of curvature R3> the radius of curvature R4 is set. It is not limited. As shown in FIGS. 12 and 13, the traction drive device 2 is configured such that the distance ratio x> distance ratio y, and the radius of curvature of the contact surfaces 200 a and 201 a of the ring roller 20 in the axial cross section of the ring roller 20. R1 and the curvature radius R2 of the contact surfaces 210 and 211 of the sun roller 21 in the axial cross section of the sun roller 21 may be set so that the curvature radius R1> the curvature radius R2. In this case, the contact surfaces 223 to 226 of the planetary roller 22 may be formed so as to incline linearly or to have an arc shape with a predetermined radius of curvature. Further, when the traction drive device is configured so that the distance ratio x <distance ratio y, the radius of curvature R3 <the radius of curvature R4 may be set.

In the embodiment , the ring roller 20 contact surfaces 200 a and 201 a are formed so as to be linear in the axial cross section of the ring roller 20, and the contact surfaces 210 and 211 of the sun roller 21 are linear in the axial cross section of the sun roller 21. The example is formed so as to become, but is not limited to this. The contact surfaces of the ring roller 20 and the sun roller 21 may be formed to have an arc shape with a predetermined radius of curvature in the axial section of the ring roller 20 and the sun roller 21.

  DESCRIPTION OF SYMBOLS 1 ... Traction drive apparatus, 10 ... Ring roller, 100 ... 1st ring roller, 101 ... 2nd ring roller, 11 ... Sun roller, 12 ... Planetary roller, 13 ... Career

Claims (3)

Ring rollers (10, 20);
A sun roller (11, 21) disposed inside the ring roller;
Planetary rollers (12, 22) pressed against the ring roller and pressed against the sun roller;
In a traction drive device that transmits power via an oil film formed between the sun roller and the planetary roller and between the planetary roller and the ring roller,
The axial direction of the planetary roller of the contact surface of the planetary roller pressed against the ring roller so that the difference between the contact surface pressure of the ring roller and the planetary roller and the contact surface pressure of the planetary roller and the sun roller is reduced. A traction drive device characterized in that a radius of curvature in a cross section and a radius of curvature in an axial cross section of the planetary roller of a contact surface of the planetary roller pressed against the sun roller are adjusted. The radius of curvature of the contact surface of the planetary roller in pressure contact with the ring roller in the axial cross section of the planetary roller and the radius of curvature of the contact surface of the planetary roller in pressure contact with the sun roller in the axial cross section of the planetary roller are: The traction drive device according to claim 1, wherein the traction drive device is set to be different from each other. The distance from the rotation center of the planetary roller to the contact point of the contact surface of the planetary roller pressed against the ring roller is L1, and the contact of the contact surface of the planetary roller pressed against the sun roller from the rotation center of the planetary roller L2 is the distance to the point, L3 is the distance from the rotation center of the sun roller to the contact point of the contact surface of the sun roller pressed against the planet roller, and the planet roller is pressed against the ring roller from the rotation center of the sun roller. Is the distance to the contact point of L4, the ratio L2 / L1 of L2 to L1 is x, and the ratio L4 / L3 of L4 to L3 is y.
When x is smaller than y, the radius of curvature of the contact surface of the planetary roller in pressure contact with the ring roller in the axial cross section of the planetary roller is the planet of the contact surface of the planetary roller in pressure contact with the sun roller. Set to be smaller than the radius of curvature in the axial section of the roller,
When x is larger than y, the radius of curvature of the contact surface of the planetary roller in contact with the ring roller in the axial cross section of the planetary roller is the planet of the contact surface of the planetary roller in contact with the sun roller. The traction drive device according to claim 2, wherein the traction drive device is set so as to be larger than a radius of curvature in an axial section of the roller.

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