JP6887355B2 - Tripod type constant velocity universal joint - Google Patents

Description

The present invention relates to a tripod type constant velocity universal joint.

As a constant velocity universal joint used in a power transmission device of an automobile or various industrial machines, there is a tripod type constant velocity universal joint using a tripod member as its inner joint member (Patent Document 1). As shown in FIGS. 30 and 31, the tripod type constant velocity universal joint includes an outer joint member 1, a tripod member 2 as an inner joint member, and a roller mechanism 3 as a torque transmission member.

The outer joint member 1 has a cup-shaped mouse portion 4 opened at one end and a stem portion 5 projecting from the bottom wall of the mouse portion 4, and is axially divided into three equal parts in the circumferential direction of the inner circumference. An extending track groove 6 is formed. Roller guide surfaces 7 and 7 are formed on the side walls of the track grooves 6 facing each other in the circumferential direction.

The tripod member 2 includes a boss portion 8 and a leg shaft 9. The boss portion 8 is formed with a spline or serration hole 10 that is coupled to the shaft so as to be able to transmit torque. The leg shaft 9 protrudes in the radial direction from the position where the boss portion 8 is divided into three equal parts in the circumferential direction.

The roller mechanism 3 is fitted to the leg shaft 9 of the tripod member 2 so as to swing swingably, and is interposed between the inner roller 11, the outer roller 12, and the inner roller 11 and the outer roller 12. The needle-shaped roller 13 to be formed is provided. The roller mechanism 3 may be referred to as a roller cassette 3.

The cylindrical outer peripheral surface 11a (see FIG. 31) of the inner roller 11 is used as the inner raceway surface, and the cylindrical inner peripheral surface 12a (see FIG. 31) of the outer roller 12 is used as the outer raceway surface. Rollers 13 intervene freely. The needle roller 13 is incorporated in a so-called full roller state with as many rollers as possible and without a cage. An annular grooves are formed at both ends of the inner peripheral surface of the outer roller 12 in the axial direction, and washers 17 and 18 for preventing the needle-shaped rollers 13 from coming off are mounted on the annular grooves.

The inner peripheral surface of the inner roller (support ring) 11 has an arcuate convex cross section. In addition to this, the cross-sectional shape of the leg shaft 9 is substantially elliptical, and a predetermined gap is provided between the leg shaft 9 and the inner roller 11, so that the inner roller 11 is in the axial direction of the leg shaft 9. Not only can it be moved by, but it can also swing and swing with respect to the leg axis 9.

Further, the opening of the outer joint member 1 is sealed by the boot 15. Here, the boot 15 includes a large-diameter portion 15a, a small-diameter portion 15b, and a bellows portion 15c that connects the large-diameter portion 15a and the small-diameter portion 15b. Therefore, the large-diameter portion 15a is fitted onto the boot mounting portion 1a formed on the outer diameter surface of the opening of the outer joint member 1, and the boot band 16 mounted on the large-diameter portion 15a is tightened to tighten the large-diameter portion. 15a is fixed to the boot mounting portion 1a of the outer joint member 1.

The shaft 20 is provided with a boot mounting portion 20b having a circumferential concave groove 20b1. Then, the small diameter portion 15b of the boot 15 is fitted onto the boot mounting portion 20b, and the small diameter portion 15b is fixed to the boot mounting portion 20b of the shaft 20 by tightening the boot band 16 mounted on the small diameter portion 15b.

By the way, conventionally, a tripod type constant velocity universal joint capable of preventing the roller mechanism 3 (roller cassette 3) from tilting to generate vibration / noise or power loss has been proposed (Patent Document 2). ). In this tripod type constant velocity universal joint, a cylindrical outer diameter surface is provided on the outer peripheral surface of the outer roller of the roller mechanism at the center in the axial direction thereof, and a cylindrical outer diameter of the outer roller is provided on the roller guide surface of the track groove of the outer joint member. A guide groove having a trapezoidal cross section is provided, which is composed of a strip-shaped plane facing the surface, an outer inclined surface provided on the outer diameter side of the strip-shaped plane, and an inner inclined surface provided on the inner diameter side of the strip-shaped plane. Then, the outer diameter portion of the outer roller of the roller mechanism is fitted into the guide groove of the roller guide surface.

Conventionally, a tripod type constant velocity universal joint capable of reducing the sliding resistance between the raceway groove of the outer ring (outer joint member) and the roller mechanism has been proposed (Patent Document 3). In this tripod type constant velocity universal joint, a support surface that comes into contact with a roller mechanism that tilts with torque transmission on the anti-torque transmission side is provided at the bottom of the raceway groove. The friction coefficient of at least one of the support surface and the end surface of the roller mechanism facing the support surface is made smaller than the friction coefficient of the transmission surface that contacts the roller mechanism and transmits torque.

Conventionally, a tripod type constant velocity universal joint capable of suppressing sliding friction between the outer ring (outer joint member) and the outer roller of the roller mechanism to reduce the forcing force has been proposed (Patent Document). 4). In this tripod type constant velocity universal joint, the outer roller is provided with an annular surface facing the ceiling surface of the track groove (track groove) of the outer ring (outer joint member), and the ceiling surface of the track groove (track groove) is provided with a roller. The first and second contact portions that come into contact with the outer edge of the annular surface when the mechanism is tilted are provided.

Conventionally, a tripod type constant velocity universal joint that enables reliable transmission and guidance of an outer roller with small friction by a small to minimum rotational play even in the case of a large error has been proposed (Patent Document 5). In this case, the convex curved surface of the outer roller and the convex curved surface (or flat surface) of the track groove come into contact with each other.

Japanese Patent No. 35999618 Japanese Unexamined Patent Publication No. 2006-12495 Japanese Unexamined Patent Publication No. 2016-118234 Japanese Unexamined Patent Publication No. 2016-1330533 Special Table 2005-528291

In the so-called double roller type low vibration tripod type constant velocity universal joint described in Patent Document 1, as shown in FIG. 31, the roller outer peripheral surface 12b, which is a rolling surface with respect to the track groove 6, has a spherical shape or an annular shape. The roller guide surface 7, which is the rolling surface of the outer roller 12, has a circular contact shape having a contact rate and an angular contact shape having a contact rate and a contact angle, following the shape of the roller outer peripheral surface 12b.

Therefore, due to the structure, when the joint rotates at an angle, the roller cassette 3 (roller mechanism) tilts in the cross section in the direction perpendicular to the axis of the outer joint member (left-right tilt: roller cassette axis, that is, around the outer roller axis Oa. (Swinging as shown by arrows A and B in FIG. 31) and the phenomenon that the roller cassette is tilted in the axially parallel cross section of the outer joint member (front-back tilt: roller cassette axis, that is, around the outer roller axis Oa). (Swinging as shown by arrows C and D) occurs. When the roller cassette 3 is tilted to the left or right and tilted back and forth, the rolling and sliding resistance at the contact portion in the track groove 6 increases, and further, the roller width surface other than the torque transmission portion, the inner diameter surface of the outer joint member 1, and the roller outer peripheral surface. There is a problem that the non-load side of the truck and the like come into contact with each other, the sliding resistance increases, and the induced force and the sliding resistance increase as NVH (Noise, Vibration, Harshness) performance of the constant velocity universal joint.

If the outer peripheral surface 12b of the roller has a cylindrical shape, it can be prevented from tilting left and right. However, in such a configuration, tilting forward and backward is likely to occur, and rolling and sliding resistance increases. There is.

The tripod type constant velocity universal joint described in Patent Document 2 can prevent the occurrence of vibration / noise and power loss. However, it is necessary to accurately configure various dimensions such as the diameter dimension of the cylindrical surface on the outer periphery of the roller mechanism, the width dimension of the cylindrical surface, and the inner diameter dimension of the roller mechanism, which is inferior in productivity.

In the tripod type constant velocity universal joint described in Patent Document 3, it is possible to reduce the sliding resistance between the raceway groove of the outer ring (outer joint member) and the roller mechanism. However, it is necessary to attach the plate member to the track groove or the roller cassette of the outer joint member, which increases the number of parts and is inferior in assembling property. Further, it is necessary to select a desired friction coefficient of each member, which is inferior in designability.

In the tripod type constant velocity universal joint described in Patent Document 4, it is possible to suppress the sliding friction between the outer ring (outer joint member) and the outer roller of the roller mechanism, thereby reducing the forcing force. However, it is necessary to set the outer diameter of the annular surface based on the roller end face diameter, the roller width which is the axial width of the outer roller, the distance between the contact portion between the annular surface and the ceiling surface, and the like, which is inferior in productivity. It will be.

The tripod type constant velocity universal joint described in Patent Document 5 enables reliable transmission and guidance of an outer roller with low friction. However, since the convex curved surface of the outer roller and the convex curved surface (or flat surface) of the track groove come into contact with each other, the outer roller can be tilted (tilted) with respect to the track groove. For this reason, the roller cassette may be tilted to the left or right or tilted back and forth.

Therefore, in view of the above problems, the present invention provides a tripod type constant velocity universal joint in which vibration caused by sliding resistance is reduced in an automobile, which directly leads to improvement of NVH characteristics and is excellent in productivity. It is to provide.

The first tripod type constant velocity universal joint of the present invention is an outer joint member having three track grooves extending in the axial direction on the inner peripheral surface and having roller guide surfaces extending in the axial direction on both sides of each track groove. A tripod member having three leg shafts protruding in the radial direction and a roller mechanism mounted on the leg shafts of the tripod member so as to swing and swing with respect to the leg shafts are provided. In a tripod type constant velocity universal joint in which the outer roller of the outer roller slides along the roller guide surface of the track groove of the outer joint member, the outer peripheral surface of the outer roller of the roller mechanism is orthogonal to the axis of the outer roller. It has an outer side surface and an inner side surface that are asymmetrically arranged with respect to a plane passing through the center point of the outer roller, and one of the outer side surface and the inner side surface is a convex curved surface and the other is a conical surface. The roller guide surface of the track groove has an outer guide surface for guiding the outer side surface and an inward guide surface for guiding the inner side surface, whichever is the outer guide surface or the inner guide surface. The guide surface is a concave curved surface that makes line contact with the convex curved surface on the outer roller side, and the other guide surface is a convex curved surface that makes point contact with the conical surface on the outer roller side. The roller mechanism may be called a roller cassette.

According to the first tripod type constant velocity universal joint of the present invention, the convex curved surface and the concave curved surface, which are the contact portions between the roller (outer roller) which is the torque transmission surface in terms of mechanism and the track groove, are in line contact. By suppressing the movement of rotating around the center of the outer roller due to this line contact and the contact between the tapered surface and the convex curved surface, the left-right tilt of the roller mechanism can be suppressed. Further, the outer peripheral surface of the outer roller and the roller guide surface are in angular contact contact, and the front-rear tilt is suppressed by this angular contact contact. As a result, the roller cassette (roller mechanism) is kept horizontal with respect to the track groove to prevent contact between the roller (outer roller) and the outer joint member except at the torque transmission point, and even when the operating angle is taken. A constant velocity universal joint with low sliding resistance.

Moreover, even if there is a slight difference in the dimensions of the convex curved surface on the outer roller side and the concave curved surface on the roller guide surface side that come into contact with each other, the convex curved surface on the outer roller side and the radius on the roller guide surface side The concave curved surface is in line contact (so-called solid contact) due to elastic deformation when a torque is applied, and the contact surface pressure can be suppressed low.

Further, even if the convex curved surface of the outer roller slides on the concave curved surface of the roller guide surface and tilts to the left or right, the convex curved surface of the guide surface and the conical surface (tapered surface) of the outer roller come into contact with each other, so that the roller cassette There is no left-right tilt. Therefore, even when rotating at an angle, the front-rear and left-right tilts of the roller cassette are reduced, and the sliding resistance of the track groove is reduced.

The second tripod type constant velocity universal joint of the present invention is an outer joint member having three axially extending track grooves formed on the inner peripheral surface and having roller guide surfaces extending axially on both sides of each track groove. A tripod member having three leg shafts protruding in the radial direction and a roller mechanism mounted on the leg shafts of the tripod member so as to swing and swing with respect to the leg shafts are provided. In a tripod type constant velocity universal joint in which the outer roller of the outer roller slides along the roller guide surface of the track groove of the outer joint member, the outer peripheral surface of the outer roller of the roller mechanism is orthogonal to the axis of the outer roller. The outer side surface and the inner side surface are arranged symmetrically with respect to the plane passing through the center point of the outer roller, and the outer side surface and the inner side surface are conical surfaces, and the roller guide of the track groove is provided. The surface has an outer guide surface for guiding the outer side surface and an inner guide surface for guiding the inner side surface, and the contact between the outer guide surface and the inner guide surface is in a torque-free state. The outer guide surface and the outer side surface, and the inner guide surface and the inner side surface are in point contact, and in a torque load state, the outer guide surface and the outer side surface, and the inner guide surface and the inner side surface are in line contact. Further, the track groove of the outer joint member is provided with an inner flange portion that receives the outer end surface of the outer roller by centrifugal force when no torque is applied.

According to the second tripod type constant velocity universal joint of the present invention, when torque is applied, the contact portion between the outer roller and the track groove, which is the torque transmission surface, becomes line contact due to elastic deformation. This line contact suppresses the left-right tilt and the front-back tilt, and the roller cassette can be kept horizontal with respect to the track groove. This prevents contact between the outer roller and the outer joint member at locations other than the torque transmission location, and enables a constant velocity universal joint with low sliding resistance even when the operating angle is taken.

Further, when the outer roller is pressed toward the outer diameter side by centrifugal force when no torque is applied, the outer roller comes into contact with the inner flange portion of the outer joint member before the guide surface. Therefore, the outer rollers come into contact with both roller guide surfaces at the same time, and sliding resistance due to the sandwiched state (wedge effect) does not occur, and high low vibration performance can be realized even when no torque is applied.

The third tripod type constant velocity universal joint of the present invention is an outer joint member having three axially extending track grooves formed on the inner peripheral surface and having roller guide surfaces extending axially on both sides of each track groove. A tripod member having three leg shafts protruding in the radial direction and a roller mechanism mounted on the leg shafts of the tripod member so as to swing and swing with respect to the leg shafts are provided. In a tripod type constant velocity universal joint in which the outer roller of the outer roller slides along the roller guide surface of the track groove of the outer joint member, the outer peripheral surface of the outer roller of the roller mechanism is orthogonal to the axis of the outer roller. The outer side surface and the inner side surface are arranged symmetrically with respect to the plane passing through the center point of the outer roller, and the outer side surface and the inner side surface are conical surfaces, and the roller guide of the track groove is provided. The surface has an outer guide surface that guides the outer side surface and an inward guide surface that guides the inner side surface, and the contact between the outer guide surface and the inward guide surface causes any of the guide surfaces. , A tapered surface that makes line contact with the mating side in a torque-free state, and a convex curved surface that makes point contact with the mating side in a torque-free state, and an outer joint member. The track groove is provided with an inner flange portion that receives the outer end surface of the outer roller by centrifugal force when no torque is applied.

According to the third tripod type constant velocity universal joint of the present invention, the contact portion between the outer roller and the roller guide surface, which is the torque transmission surface in terms of mechanism, is orthogonal to the axis of the outer roller in a torque-free state. Line contact (straight contact) occurs on the outer diameter side or inner diameter side of the plane passing through the center point of the outer roller. This linear contact suppresses the left-right tilt of the roller cassette, and further, the outer peripheral surface of the other outer roller and the roller guide surface make angular contact contact, and this angular contact contact suppresses the front-back tilt. As a result, the roller cassette (roller mechanism) is kept horizontal with respect to the track groove, preventing contact between the roller (outer roller) and the outer joint member other than the torque transmission point, and even when the operating angle is taken. A constant velocity universal joint with low sliding resistance.

By making one of the outer guide surface and the inner guide surface of the track groove a tapered track, even if there is a slight taper angle difference between the outer roller and the outer joint member, the convex curved surface of the other guide surface It absorbs this and secures a straight line contact in part, enabling a constant velocity universal joint (a constant velocity universal joint with low sliding resistance) that has the desired function (function excellent in low vibration performance).

Further, when the outer roller is pressed toward the outer diameter side by centrifugal force when no torque is applied, the outer roller comes into contact with the inner flange portion of the outer joint member before the guide surface. Therefore, the outer rollers come into contact with both roller guide surfaces at the same time, no sliding resistance is generated due to the sandwiched state (wedge effect), and high low vibration performance can be realized even when no torque is applied.

The fourth tripod type constant velocity universal joint of the present invention is an outer joint member having three axially extending track grooves formed on the inner peripheral surface and having roller guide surfaces extending axially on both sides of each track groove. A tripod member having three leg shafts protruding in the radial direction and a roller mechanism mounted on the leg shafts of the tripod member so as to swing and swing with respect to the leg shafts are provided. In a tripod type constant velocity universal joint in which the outer roller of the outer roller slides along the roller guide surface of the track groove of the outer joint member, the outer peripheral surface of the outer roller of the roller mechanism is orthogonal to the axis of the outer roller. It has an outer side surface and an inner side surface that are asymmetrically arranged with respect to a plane passing through the center point of the outer roller, and one side surface of the outer side surface and the inner side surface is a conical surface and the other side. The roller guide surface of the track groove has an outer guide surface for guiding the outer side surface and an inner guide surface for guiding the inner side surface, and the outer guide surface and the inner guide surface are provided. One of the guide surfaces with the direction guide surface is a concave curved surface that makes line contact with the convex curved surface of the outer roller in the torque no load state, and the other guide surface is the conical surface of the outer roller in the torque no load state. It has a convex curved surface that makes point contact with the surface, and further, an inner flange portion that receives the outer end surface of the outer roller by centrifugal force when no torque is applied is provided in the track groove of the outer joint member.

According to the fourth tripod type constant velocity universal joint of the present invention, in a torque-free state, the convex curved surface and the concave curved surface, which are the contact portions between the outer roller, which is the torque transmission surface on the mechanism, and the roller guide surface, are in line contact. It becomes. The left-right tilt of the roller cassette can be suppressed by suppressing the movement of rotating around the center of the outer roller due to this line contact and the contact between the outer tapered surface and the convex curved surface. Furthermore, when the roller cassette tries to tilt back and forth, the contact point between the inner side surface and the outer guide surface moves inward in the roller width direction, and the center of the roller moves away from the guide surface. The roller is pressed against the guide surface to prevent it from tilting back and forth. As a result, the roller cassette (roller mechanism) is kept horizontal with respect to the track groove, prevents contact between the roller (outer roller) and the outer joint member except at the torque transmission point, and even when the operating angle is taken. , A constant velocity universal joint with low sliding resistance.

Even if there is a slight difference in the dimensions of the convex curved surface on the outer roller side and the concave curved surface on the roller guide surface side that come into contact with each other, the convex curved surface on the outer roller side and the concave curved surface on the roller guide surface side When a torque is applied, elastic deformation causes line contact (so-called solid contact), and the contact surface pressure can be suppressed low. Moreover, even if the outer roller slides on the radius of the track groove and tries to tilt left and right, the convex radius on the opposite side and the tapered surface of the outer roller come into contact with each other, so that the roller cassette does not tilt left and right. Therefore, it is possible to obtain a constant velocity universal joint (a constant velocity universal joint having a low sliding resistance) having a target function (a mechanism excellent in low vibration performance).

Further, when the outer roller is pressed toward the outer diameter side by centrifugal force when no torque is applied, the outer roller comes into contact with the inner flange portion of the outer joint member before the guide surface. Therefore, the outer rollers come into contact with both roller guide surfaces at the same time, no sliding resistance is generated due to the sandwiched state (wedge effect), and high low vibration performance can be realized even when no torque is applied.

In the second to third tripod type constant velocity universal joints, the angle formed by the conical surface and the plane orthogonal to the axis of the outer roller and passing through the center point of the outer roller (this angle is the roller outer diameter conical surface). (Called the angle of) can be set to 60 ° to 80 °.

If the angle of the outer diameter conical surface of the roller is less than 60 °, the outer roller rolls closer to the center of the roller and closer to the width surface due to contact with the track groove, and the difference in peripheral speed becomes large, which increases the rotational resistance. Furthermore, since the contact load also increases, it is desirable that the angle is greater than that. Further, when the angle of the outer diameter conical surface of the roller is larger than 80 ° (when it exceeds 80 °), the posture control effect of the front-back tilt of the outer roller becomes small. As a result, contact with the non-load side is likely to occur and rotational resistance is generated. Therefore, the angle or less is desirable. Therefore, it can be said that the angle of the roller outer diameter conical surface is preferably 70 ° ± 5 °.

The maximum contact angle of the line contact portion can be set to 10 ° to 30 °. If the maximum contact angle is less than 10 °, the wedge angle (contact angle) is small when no torque is applied, and the sliding resistance at that time is large. Further, when the maximum contact angle is larger than 30 °, the rolling peripheral speed difference becomes large near the center of the roller and near the width surface due to the contact with the track groove, the rotational resistance increases, and the vibration reduction effect is reduced. Therefore, it can be said that the contact angle is preferably 20 ° ± 5 °.

Even if the outer diameter surface cross-sectional shape of the leg shaft of the tripod member is a convex curved surface and the inner diameter surface of the inner roller is a cylindrical surface, the outer diameter surface cross-sectional shape of the leg shaft of the tripod member is a convex curved surface. The inner diameter surface of the inner roller may be a concave curved surface that fits into the convex curved surface of the leg shaft.

In the tripod type constant velocity universal joint of the present invention, the front-rear and left-right inclination of the roller cassette (roller mechanism) is reduced when rotating at an angle, and the sliding resistance of the track groove is reduced. In automobiles, vibration caused by sliding resistance is reduced, which directly leads to improvement of NVH characteristics.

It is a vertical sectional view of the 1st tripod type constant velocity universal joint of this invention. It is a cross-sectional view of the tripod type constant velocity universal joint shown in FIG. It is sectional drawing of the main part of the tripod type constant velocity universal joint shown in FIG. FIG. 2 is an enlarged cross-sectional view of a main part of the tripod type constant velocity universal joint shown in FIG. FIG. 5 is an enlarged cross-sectional view of a main part of a tripod type constant velocity universal joint in which the outer surface of the outer peripheral surface of the roller is a conical surface. FIG. 5 is an enlarged cross-sectional view of a main part of a tripod type constant velocity universal joint in which the outer diameter surface cross-sectional shape of the leg shaft of the tripod member is a convex curved surface and the inner diameter surface of the inner roller is a cylindrical surface. The outer diameter surface cross-sectional shape of the leg shaft of the tripod member is a convex curved surface, and the inner diameter surface of the inner roller is a concave curved surface that fits into the convex curved surface of the leg shaft. It is a figure. It is a vertical sectional view of the 2nd tripod type constant velocity universal joint of this invention. It is a cross-sectional view of the tripod type constant velocity universal joint shown in FIG. FIG. 9 is an enlarged cross-sectional view of a main part of the tripod type constant velocity universal joint shown in FIG. 9 when no load is applied. FIG. 9 is an enlarged cross-sectional view of a main part of the tripod type constant velocity universal joint shown in FIG. 9 when a torque is applied. FIG. 9 is an enlarged cross-sectional view of a main part of the tripod type constant velocity universal joint shown in FIG. 9 when a centrifugal force is applied. The relationship between the gap between the outer end surface of the outer roller and the inner flange portion that receives it and the gap between the outer side surface of the outer roller and the roller guide surface when the tripod type constant velocity universal joint shown in FIG. 9 is unloaded. It is an enlarged sectional view of the main part shown. It is a cross-sectional view of a tripod type constant velocity universal joint in which the outer guide surface of the roller guide surface is a tapered surface and the inner guide surface of the roller guide surface is a convex curved surface. FIG. 14 is an enlarged cross-sectional view of a main part of the tripod type constant velocity universal joint shown in FIG. 14 when no load is applied. It is a cross-sectional view of a tripod type constant velocity universal joint in which the outer guide surface of the roller guide surface is a convex curved surface and the inner guide surface of the roller guide surface is a tapered surface. The outer peripheral surface of the outer roller has a conical inner surface and a convex curved surface, the outer guide surface of the roller guide surface is a concave curved surface, and the inner guide surface of the roller guide surface is a convex curved surface. It is an enlarged sectional view of the main part of a tripod type constant velocity universal joint. The outer peripheral surface of the outer roller has a convex curved surface on the inner surface, a conical surface on the outer surface, a convex curved surface on the outer guide surface of the roller guide surface, and a concave curved surface on the inner guide surface of the roller guide surface. It is an enlarged sectional view of the main part of a tripod type constant velocity universal joint. FIG. 14 is an enlarged cross-sectional view of a main part of the tripod type constant velocity universal joint shown in FIG. 14 when a centrifugal force is applied. The relationship between the gap between the outer end surface of the outer roller and the inner flange portion that receives the tripod type constant velocity universal joint shown in FIG. 14 and the gap between the outer side surface of the outer roller and the roller guide surface when there is no load. It is an enlarged sectional view of the main part shown. FIG. 16 is an enlarged cross-sectional view of a main part of the tripod type constant velocity universal joint shown in FIG. 16 when a centrifugal force is applied. The relationship between the gap between the outer end surface of the outer roller and the inner flange portion that receives the tripod type constant velocity universal joint shown in FIG. 16 and the gap between the outer side surface of the outer roller and the roller guide surface when there is no load. It is an enlarged sectional view of the main part shown. FIG. 17 is an enlarged cross-sectional view of a main part of the tripod type constant velocity universal joint shown in FIG. 17 when a centrifugal force is applied. The relationship between the gap between the outer end surface of the outer roller and the inner flange portion that receives it and the gap between the outer side surface of the outer roller and the roller guide surface when the tripod type constant velocity universal joint shown in FIG. 17 is unloaded. It is an enlarged sectional view of the main part shown. FIG. 18 is an enlarged cross-sectional view of a main part of the tripod type constant velocity universal joint shown in FIG. 18 when a centrifugal force is applied. The relationship between the gap between the outer end surface of the outer roller and the inner flange portion that receives the tripod type constant velocity universal joint shown in FIG. 18 and the gap between the outer side surface of the outer roller and the roller guide surface when there is no load. It is an enlarged sectional view of the main part shown. On the outer peripheral surface of the outer roller, the outer side surface and the inner side surface are conical surfaces, the outer guide surface and the inner guide surface of the roller guide surface are convex curved surfaces, and the outer diameter surface cross-sectional shape of the leg shaft of the tripod member is a convex curved surface. It is an enlarged cross-sectional view of a main part of a tripod type constant velocity universal joint in which the inner diameter surface of the inner roller is a cylindrical surface. The outer peripheral surface of the outer roller has a conical surface on the outer side surface and the inner side surface, and the roller guide surface has a tapered surface on the outer guide surface and a convex curved surface on the inner guide surface. FIG. 5 is an enlarged cross-sectional view of a main part of a tripod type constant velocity universal joint in which the diameter surface cross-sectional shape is a convex curved surface and the inner diameter surface of the inner roller is a cylindrical surface. As for the outer peripheral surface of the outer roller, the inner side surface (inner side surface) is a conical surface, the outer side surface (outer surface) is a convex curved surface, and the outer guide surface of the roller guide surface is a concave curved surface. The inner guide surface of the surface is a convex curved surface, the outer diameter surface cross-sectional shape of the leg shaft of the tripod member is a convex curved surface, and the inner diameter surface of the inner roller is a cylindrical surface. It is a sectional view. It is a vertical cross-sectional view of the conventional tripod type constant velocity universal joint which shows the front-rear inclination of a roller cassette. It is a cross-sectional view of the conventional tripod type constant velocity universal joint which shows the left-right inclination of a roller cassette.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 29. As shown in FIGS. 1 and 2, the tripod type constant velocity universal joint according to the present invention includes an outer joint member 31, a tripod member 32 as an inner joint member, and a torque transmission member. The roller mechanism 33 is provided.

The outer joint member 31 has a cup-shaped mouse portion 34 opened at one end and a stem portion 35 projecting from the bottom wall of the mouse portion 34, and is axially divided into three equal parts in the circumferential direction of the inner circumference. An extending track groove 36 is formed. When viewed in cross section, the mouse portion 34 has a non-cylindrical shape in which large diameter portions 34a and small diameter portions 34b appear alternately, as shown in FIG. That is, by forming the large diameter portion 34a and the small diameter portion 34b of the mouse portion 34, the three track grooves 36 extending in the axial direction are formed on the inner peripheral surface thereof.

Roller guide surfaces (roller sliding contact surfaces) 37, 37 are formed on the side walls of the track grooves 36 facing each other in the circumferential direction. Further, the inner diameter surface has a three-valve flower crown shape in which small inner diameter portions 45 and large inner diameter portions 46 appearing alternately in the circumferential direction are connected by a roller guide surface 37. That is, in the outer joint member 31, track grooves 36 composed of a roller guide surface 37 facing in the circumferential direction and a large inner diameter portion 46 provided between the roller guide surfaces 37 and 37 are formed at three locations on the inner circumference. It is a thing.

The tripod member 32 includes a boss portion 38 and a leg shaft 39. A female spline 40a is formed on the inner diameter surface of the axial core hole 40 of the boss portion 38, and a male spline 50a at the end of the shaft 50 is fitted into the axial core hole 40. Therefore, the male spline 50a of the shaft 50 meshes with the female spline 40a of the boss portion 38. The leg shaft 39 protrudes in the radial direction from the position of the boss portion 38 divided into three equal parts in the circumferential direction. A retaining ring 51 for preventing the shaft from coming off is attached to the end of the shaft 50 protruding from the shaft center hole 40.

The roller mechanism 33 is fitted to the leg shaft 39 of the tripod member 32 so as to swing swingably, and is interposed between the inner roller 41, the outer roller 42, and the inner roller 41 and the outer roller 42. It is provided with a needle-shaped roller 43 to be formed. The roller mechanism 33 may be called a roller cassette.

The cylindrical outer peripheral surface 41a (see FIGS. 2 and 3) of the inner roller 41 is used as the inner raceway surface, and the cylindrical inner peripheral surface 42a (see FIGS. 2 and 3) of the outer roller 42 is used as the outer raceway surface. A needle-shaped roller 43 is rotatably interposed between the raceway surfaces. The needle roller 43 is incorporated in a so-called full roller state with as many rollers as possible and without a cage. An annular grooves are formed at both ends of the inner peripheral surface of the outer roller 42 in the axial direction, and washers 47 and 48 for preventing the needle-shaped rollers 43 from coming off are mounted on the annular grooves.

The outer peripheral surface of the leg shaft 39 has a straight shape parallel to the axis of the leg shaft 39 when viewed in the vertical section, and an elliptical shape whose long axis is orthogonal to the axis of the joint when viewed in the cross section. The cross-sectional shape of the leg shaft 39 is substantially elliptical by reducing the wall thickness of the tripod member 32 as seen in the axial direction. In other words, in the cross-sectional shape of the leg shaft 39, the surfaces of the tripod member 32 facing each other in the axial direction are retracted in the mutual direction, that is, on the smaller diameter side than the virtual cylindrical surface.

The inner peripheral surface of the inner roller (support ring) 41 has an arcuate convex cross section. Since the cross-sectional shape of the leg shaft 39 is substantially elliptical as described above and a predetermined gap is provided between the leg shaft 39 and the inner roller 41, the inner roller 41 is a leg shaft. Not only is it possible to move the 39 in the axial direction, but it is also swingable with respect to the leg axis 39.

Further, the opening of the outer joint member 31 is sealed by the boot 55. Here, the boot 55 includes a large-diameter portion 55a, a small-diameter portion 55b, and a bellows portion 55c that connects the large-diameter portion 55a and the small-diameter portion 55b. Therefore, the large-diameter portion 55a is fitted onto the boot mounting portion 31a formed on the outer diameter surface of the opening of the outer joint member 31, and the boot band 56 mounted on the large-diameter portion 55a is tightened to tighten the large-diameter portion. 55a is fixed to the boot mounting portion 31a of the outer joint member 31.

The shaft 50 is provided with a boot mounting portion 50b having a circumferential recessed groove 50b1. Then, the small diameter portion 55b of the boot 55 is fitted onto the boot mounting portion 50b, and the boot band 56 mounted on the small diameter portion 55b is tightened to fix the small diameter portion 55b to the boot mounting portion 50b of the shaft 50.

By the way, as shown in FIG. 4, the outer peripheral surface 60 of the outer roller 42 of the roller mechanism 33 has an outer side surface 60a and an inner side surface 60b. In this case, the outer side surface 60a is a convex curved surface, and the inner side surface 60b is a tapered surface (conical surface). Therefore, the outer roller 42 is arranged asymmetrically with respect to the plane H orthogonal to the axis L1 (see FIGS. 1 and 3) of the outer roller 42 and passing through the center point Oa (see FIGS. 1 and 3) of the outer roller 42. In the state shown in FIG. 1, the axis Lo of the leg axis 39 is orthogonal to the axis L of the shaft 50, and the axis L1 of the outer roller 42 and the axis L1 of the leg axis 39 coincide with each other. .. _{The taper angle θ R} (see FIG. 4) of the tapered surface (conical surface) of the inner side surface 60b is set to about 60 ° to 80 °.

Further, as shown in FIG. 4, the roller guide surface 37 also has an outer guide surface 37a and an inner guide surface 37b, and the outer guide surface 37a is a concave curved surface that makes line contact with the convex curved surface of the outer side surface 60a. The inward guide surface 37b is a convex curved surface that makes point contact with the conical surface of the inward side surface 60b. When the radius of curvature of the outer side surface 60a of the outer roller 42 is R _R and the radius of curvature of the outer guide surface 37a of the roller guide surface 37 is R _T , then R _R ≈ R _T. Here, the radius of curvature R of the inward guide surface 37b is about the same as _RR ( _RT). In FIG. 4, S indicates a contact portion between the outer peripheral surface 60 of the outer roller 42 and the roller guide surface 37.

With this configuration, the convex and concave curved surfaces, which are the contact portions S between the roller (outer roller) 42, which is the torque transmission surface on the mechanism, and the roller guide surface 37, are in line contact. The left-right tilt of the roller cassette 33 can be suppressed by suppressing the movement of rotating around the center of the outer roller due to the line contact and the contact between the tapered surface and the convex curved surface. Here, the left-right inclination means that, as shown in FIG. 31, the outer roller 12 swings with respect to the opposing roller guide surfaces 7 and 7 with the axis Oa as the center as shown by arrows A and B. Is. Further, since the outer side surface 60a of the outer roller 42 is an annular surface, the outer roller 12 tilts back and forth (as shown in FIG. 31, the outer roller 12 swings around its axis Oa as shown by arrows C and D). That) is suppressed.

Therefore, in this tripod type constant velocity universal joint, the roller cassette 33 is kept horizontal with respect to the track groove 36, prevents contact between the outer roller 42 and the outer joint member 31 other than the torque transmission portion, and takes an operating angle. Even in such a case, it becomes a constant velocity universal joint with low sliding resistance.

Even if there is a slight difference between the radius of curvature R _R and the radius of curvature R _T , it will be a solid contact (line contact) due to elastic deformation when a torque is applied. Therefore, the contact surface pressure can be suppressed to a low level, and even if the outer roller 42 slides on the concave curved surface of the roller guide surface 37 and tries to cause a left-right inclination, the convex curved surface of the guide surface 37 and the conical surface (taper) of the outer roller 42. The surface) comes into contact with each other so that the outer roller 42 does not tilt to the left or right.

As described above, in the tripod type constant velocity universal joint shown in FIG. 1 and the like, the lateral tilt and the front-back tilt of the roller mechanism (roller cassette) 33 can be effectively prevented, and the contact portion S between the outer roller 42 and the track groove 36 (FIG. The rolling and sliding resistance in (see 4) does not increase. Therefore, it is possible to obtain a tripod type constant velocity universal joint capable of reducing vibration caused by sliding resistance and improving NVH characteristics.

Further, it is preferable that the contact angle θc (see FIG. 4) of the end (outer diameter end) of the contact surface between the concave curved surface of the roller guide surface 37 and the outer roller 42 and the convex curved surface is 10 ° or more. By setting in this way, the wedge action can be reduced. That is, the rolling resistance of the outer roller 42 can be reduced. Therefore, high low vibration performance can be exhibited. In this case, the maximum contact angle of the line contact portion (maximum contact angle between the outer roller 42 and the roller guide surface 37 of the track groove 36) can be set to 10 ° to 30 °. If the maximum contact angle is less than 10 °, the wedge angle (contact angle) is small when no torque is applied, and the sliding resistance at that time is large. Further, when the maximum contact angle is larger than 30 °, the contact with the track groove 36 causes a large difference in rolling peripheral speed between the center of the roller and the width surface, which increases the rotational resistance and reduces the vibration reduction effect. Therefore, it can be said that the contact angle is preferably 20 ° ± 5 °.

Therefore, as shown in FIG. 3, the wedge angle θ can be made larger than the wedge angle θ of the conventional tripod type constant velocity universal joint shown in FIG. 31, and the outer roller 42 is bitten by the wedge effect. It can be suppressed advantageously.

By the way, in the tripod type constant velocity universal joint shown in FIGS. 1 to 4, the outer side surface 60a is a convex curved surface and the inner side surface 60b is a tapered surface (conical surface), but as shown in FIG. The outer side surface 60a may be a tapered surface (conical surface), and the inner side surface 60b may be a convex curved surface.

Therefore, in the tripod type constant velocity universal joint shown in FIG. 5, the roller guide surface 37 of the track groove 36 has the outer guide surface 37a as a convex curved surface that makes point contact with the conical surface, and the inner guide surface 37b as a convex surface. It is a concave curved surface that makes line contact with the curved surface. Also in this case, the maximum contact angle of the line contact portion (the maximum contact angle between the outer roller 42 and the roller guide surface 37 of the track groove 36) is set to 10 ° to 30 °, and the radius of curvature of the inner side surface 60b of the outer roller 42 is set. was a R _R, the radius of curvature of the inner guide surface 37b of the roller guide surface 37 is taken as R _T, and _R R ≒ R _{T. Further, the taper angle θ R} of the tapered surface (conical surface) of the outer side surface 60a is set to about 60 ° to 80 °.

Therefore, the tripod-type constant-velocity universal joint shown in FIG. 5 can also have the same effect as the tripod-type constant-velocity universal joint shown in FIGS. 1 to 4. In FIG. 5, S indicates a contact portion between the outer peripheral surface 60 of the outer roller 42 and the roller guide surface 37.

In the tripod type constant velocity universal joint shown in FIG. 6, the outer diameter surface 39a of the leg shaft 39 of the tripod member 32 is a convex curved surface, and the inner diameter surface 41b of the inner roller 41 is a cylindrical surface. That is, as the tripod type constant velocity universal joint shown in FIG. 6, the type in which the outer diameter surface 39a of the leg shaft 39 of the tripod member 32 is a convex curved surface and the outer roller 42 is of the type shown in FIGS. In line with this, the outer joint member 31 of the type shown in FIGS. 1 to 4 is used.

Therefore, the tripod type constant velocity universal joint shown in FIG. 6 can also have the same effect as the tripod type constant velocity universal joint shown in FIGS. 1 to 4. Moreover, the roller mechanism (roller cassette) 33 can perform a turning and turning motion with respect to the leg axis (trunnion) 39, and the roller mechanism 33 and the leg axis (trunnion) 39 are relative to each other in the axial direction of the leg axis 39. It becomes movable.

Further, in the tripod type constant velocity universal joint shown in FIG. 7, the inner diameter surface 41b of the inner roller 41 is a concave curved surface that fits into the convex curved surface of the outer diameter surface 39a of the leg shaft 39. The tripod-type constant-velocity universal joint shown in FIG. 7 can also exhibit the same effects as those of the tripod-type constant-velocity universal joint shown in FIGS. 1 to 4. Moreover, the roller mechanism (roller cassette) 33 can stably perform a turning and turning motion with respect to the leg shaft (trunnion) 39. The constant velocity universal joint shown in FIG. 7 is the same except that the constant velocity universal joint shown in FIG. 6 and the outer diameter surface 39a of the leg shaft 39 and the inner diameter surface 41b of the inner roller 41 are different from each other. ..

Next, in the tripod type constant velocity universal joints shown in FIGS. 8 to 11, the outer side surface 60a of the outer roller 42 is a tapered surface (conical surface) and the inner side surface 60b is a tapered surface (conical surface). .. In this case, the outer side surface 60a and the inner side surface 60b are arranged orthogonally to the axial center line of the outer roller 42 and symmetrically with respect to the plane H passing through the center point Oa of the outer roller 42.

Further, the roller guide surface 37 of the track groove 36 corresponds to the outer side surface 60a and the inner side surface 60b of the outer roller 42, and the outer guide surface 37a and the inner guide surface 37b have convex curved surfaces, respectively.

In this case, as the radius of curvature R of the outer guide surface 37a and the inner guide surface 37b, as shown in FIG. 10, the outer guide surface 37a and the outer side surface 60a are in point contact with each other and the inner guide surface is in contact with each other. The 37b and the inner side surface 60b make point contact. Further, in the state under torque load, in the state shown in FIG. 11, the contact portion is elastically deformed, the outer guide surface 37a and the outer side surface 60a are in line contact, and the inner guide surface 37b and the inner side surface 60b are in line contact with each other. Makes line contact.

Therefore, this line contact suppresses the left-right tilt and the front-back tilt, and the roller cassette 33 is kept horizontal with respect to the track groove 36 to prevent the outer roller 42 and the outer joint member from coming into contact with each other except at the torque transmission point. Even when the working angle is taken, a constant velocity universal joint with low sliding resistance is possible.

Further, the track groove 36 of the outer joint member 31 of the tripod type constant velocity universal joint is provided with an inner flange portion 61 that receives the outer end surface of the outer roller 42 by centrifugal force when no torque is applied. In this case, as shown in FIG. 13, the dimension between the inner flange portion 61 of the outer joint member 31 and the outer end surface of the outer roller 42 is a, and the outer side surface 60a of the outer peripheral surface 60 of the outer roller 42 and the roller. When the gap between the guide surface 37 and the outer guide surface 37a is b, it is set to a <b.

As a result, when the outer roller 42 is pressed against the outer joint member 31 by centrifugal force when no torque is applied, the outer roller 42 is placed on the axis L1 of the outer roller 42 of the roller cassette 33, as shown in FIG. The plane H that is orthogonal and passes through the axial center (center) Oa of the outer roller 42 moves in the outer radial direction like H', and the inner flange portion 61 comes into contact with the inner flange portion 61.

However, since a <b is set, the inner flange portion 61 comes into contact with the roller guide surface 37 before it comes into contact with the roller guide surface 37. Therefore, the wedge effect does not occur between the outer peripheral surface 60 of the outer roller 42 and the roller guide surface 37, and high low vibration performance can be realized even when no torque is applied.

By the way, in the tripod type constant velocity universal joint shown in FIGS. 8 to 11, the outer side surface 60a and the inner side surface 60b of the outer roller 42 are orthogonal to the axial center line of the outer roller 42 and have the center point of the outer roller 42. _{The angle θ R} formed with the passing plane H (this angle may be referred to as the angle of the roller outer diameter conical surface) is preferably 60 ° to 80 °.

_{If the angle θ R} of the outer diameter conical surface of the roller is less than 60 °, the outer roller 42 rolls closer to the center of the roller and closer to the width surface due to contact with the track groove 36, and the difference in peripheral speed increases, increasing the rotational resistance. Become. Furthermore, since the contact load also increases, it is desirable that the angle is greater than that. Further, when it is larger than 80 ° (when it exceeds 80 °), the posture control effect of the front-rear tilt of the outer roller 42 becomes small. As a result, contact with the non-load side is likely to occur and rotational resistance is generated. Therefore, the angle or less is desirable. Therefore, it can be said that the angle of the conical surface is preferably 70 ° ± 5 °. In FIGS. 10, 11, and 12, S indicates a contact portion between the outer peripheral surface 60 of the outer roller 42 and the roller guide surface 37. S1 of FIG. 12 shows a contact portion between the outer end surface of the outer roller 42 and the inner flange portion 61 of the outer joint member 31.

Further, in the tripod type constant velocity universal joint shown in FIGS. 14 and 15, the outer side surface 60a of the outer roller 42 is a tapered surface (conical surface) and the inner side surface 60b is a tapered surface (conical surface). The outer guide surface 37a of the roller guide surface 37 of the outer joint member 31 is a tapered surface facing the tapered surface of the outer side surface 60a, and the inner guide surface 37b of the roller guide surface 37 is a convex curved surface. Therefore, in a torque-free state, the tapered surface (conical surface) of the outer side surface 60a and the tapered surface of the outer guide surface 37a are in line contact, and the tapered surface (conical surface) of the inner side surface 60b and the inner guide surface 37b. Is a point contact.

In this case, as shown in FIG. 15, the outer tapered surface of the side 60a angle theta _R a 60 ° respectively - the angle theta _R, and the inner side surface 60b tapered surface of the (conical surface) (conical surface) It is set to 80 °. _{Further, the angle θ T} formed by the tapered surface of the outer guide surface 37a is also set to 60 ° to 80 °. That is, it is set to _{θ R} ≈ θ _T.

Therefore, as shown in FIGS. 14 and 15, the contact portion between the outer roller 42 and the roller guide surface 37, which is the torque transmission surface on the mechanism, is orthogonal to the axial core line of the outer roller 42 in a torque-free state. Line contact (straight line contact) occurs on the outer diameter side of the plane H passing through the center point Oa of the outer roller 42. This linear contact suppresses the left-right tilt of the roller cassette (roller mechanism) 33, and when the roller cassette 33 tries to tilt back and forth, the contact point between the inner side surface 60b and the outer guide surface 37b moves inward in the roller width direction. Since the center of the roller is separated from the guide surface, the roller is pressed against the guide surface by the contact force due to the torque load, and the front-rear inclination is suppressed. As a result, the roller cassette (roller mechanism) 33 is kept horizontal with respect to the track groove, prevents contact between the roller (outer roller 42) and the outer joint member except at the torque transmission point, and when the operating angle is taken. However, it is a constant velocity universal joint with low sliding resistance.

By making only the outer guide surface 37a of the roller guide surface 37 a taper track, even if a slight taper angle difference occurs between the taper of the outer roller 42 and the taper of the outer joint member 31, the inner guide surface 37b can be used for it. It absorbs and secures a straight line contact on the inner diameter side, enabling a constant velocity universal joint (a constant velocity universal joint with low sliding resistance) having the desired function (function excellent in low vibration performance).

In the tripod type constant velocity universal joint shown in FIG. 16, the outer side surface 60a of the outer roller 42 is a tapered surface (conical surface) and the inner side surface 60b is a tapered surface (conical surface). The outer guide surface 37a of the roller guide surface 37 is a convex curved surface, and the inner guide surface 37b of the roller guide surface 37 is a tapered surface facing the tapered surface of the inner side surface 60b. Therefore, in a torque-free state, the tapered surface (conical surface) of the outer side surface 60a and the tapered surface of the outer guide surface 37a are in line contact, and the tapered surface (conical surface) of the inner side surface 60b and the inner guide surface 37b. Is a point contact. (That is, the radius of curvature R of the inward guide surface 37b is a size that makes point contact in this way.)

Again, it is angle theta _R of the tapered surface of the outer side surface 60a (conical surface), and the inner tapered surface of the side 60b of the angle theta _R of (conical surface) and 60 ° to 80 °, respectively. _{Further, the angle θ T} formed by the tapered surface of the inward guide surface 37b is also set to 60 ° to 80 °. That is, it is set to _{θ R} ≈ θ _T.

In the tripod type constant velocity universal joint configured as shown in FIG. 16, the contact portion between the outer roller 42 and the roller guide surface 37, which is the torque transmission surface in terms of mechanism, is in a torque-free state, and the axial center of the outer roller 42 is in a torque-free state. Line contact (straight line contact) occurs on the inner diameter side of the plane H that is orthogonal to the line and passes through the center point Oa (see FIG. 14) of the outer roller 42. Therefore, even the tripod type constant velocity universal joint configured as shown in FIG. 16 has the same effect as that of the tripod type constant velocity universal joint shown in FIG. In FIGS. 15 and 16, S indicates a contact portion between the outer peripheral surface 60 of the outer roller 42 and the roller guide surface 37.

In the tripod type constant velocity universal joint shown in FIG. 17, the outer side surface 60a of the outer peripheral surface 60 of the outer roller 42 is a convex curved surface, and the inner side surface 60b is a conical surface. Further, the outer guide surface 37a of the roller guide surface 37 of the outer joint member 31 is a concave curved surface that fits into the convex curved surface of the outer side surface 60a, and the inner guide surface 37b of the roller guide surface 37 is a convex curved surface.

_{Also in this case, the angle θ R} formed by the tapered surface (conical surface) of the inner side surface 60b is set to 60 ° to 80 °. Further, when the radius of curvature of the outer side surface 60a of the outer roller 42 is R _R and the radius of curvature of the outer guide surface 37a of the roller guide surface 37 is R _T , then R _R ≈ R _{T. The angle θ R} formed by the tapered surface (conical surface) of the inner side surface 60b is set to 60 ° to 80 °, respectively. _{Further, the angle θ T} formed by the tapered surface of the inward guide surface 37b is also set to 60 ° to 80 °. That is, it is set to _{θ R} ≈ θ _T. The maximum contact angle of the line contact portion (maximum contact angle between the outer roller 42 and the roller guide surface 37 of the track groove 36) can be set to 10 ° to 30 °.

In the torque-free state, the convex curved surface and the concave curved surface, which are the contact portions S between the outer roller 42, which is the torque transmission surface on the mechanism, and the roller guide surface 37, are in line contact. By this line contact and the contact between the tapered surface and the convex curved surface, the movement of rotating around the center of the outer roller can be suppressed, and the left-right tilt of the roller cassette 33 can be suppressed. Further, when the roller cassette 33 tries to tilt back and forth, the contact point between the inner side surface 60b and the outer guide surface 37b moves inward in the roller width direction, and the center of the roller is separated from the guide surface. The forward and backward tilt of the roller is suppressed by the action of pressing the roller against the guide surface by the force. As a result, the roller cassette (roller mechanism) 33 is kept horizontal with respect to the track groove 36, prevents contact between the outer roller 42 and the outer joint member 31 other than the torque transmission portion, and even when the operating angle is taken. , A constant velocity universal joint with low sliding resistance.

Moreover, in the tripod type constant velocity universal joint shown in FIG. 17, _{even if there is a slight difference between the radius of curvature R R} and the radius of curvature R _T , when a torque load is applied, the contact surface pressure becomes solid due to elastic deformation (line contact). Even if the outer roller 42 slides on the track groove and tries to tilt left and right, the roller cassette (roller mechanism) 33 tilts left and right due to the contact between the inner guide surface 37b and the tapered surface of the outer roller 42. Does not occur.

In the tripod type constant velocity universal joint shown in FIG. 18, the outer side surface 60a of the outer peripheral surface 60 of the outer roller 42 is a conical surface, and the inner side surface 60b is a convex curved surface. Further, the outer guide surface 37a of the roller guide surface 37 of the outer joint member 31 is a convex curved surface, and the inner guide surface 37b of the roller guide surface 37 is a concave curved surface that fits into the convex curved surface of the inner side surface 60b.

_{Also in this case, the angle θ R} formed by the tapered surface (conical surface) of the outer side surface 60a is set to 60 ° to 80 °. Further, when the radius of curvature of the inner side surface 60b of the outer roller 42 is R _R and the radius of curvature of the inner guide surface 37b of the roller guide surface 37 is R _T , then R _R ≈ R _T. The maximum contact angle of the line contact portion (maximum contact angle between the outer roller 42 and the roller guide surface 37 of the track groove 36) can be set to 10 ° to 30 °.

In the tripod type constant velocity universal joint shown in FIG. 18, the tapered surface (conical surface) of the outer side surface 60a and the convex curved surface of the outer guide surface 37a are in point contact with each other in a torque-free state, and the convex curved surface of the inner side surface 60b. And the concave curved surface of the inward guide surface 37b are in line contact with each other.

Therefore, even the tripod type constant velocity universal joint shown in FIG. 18 has the same effect as the report type constant velocity universal joint shown in FIG. In FIGS. 17 and 18, S indicates a contact portion between the outer peripheral surface 60 of the outer roller 42 and the roller guide surface 37.

By the way, as shown in FIGS. 19 to 26, the tripod type constant velocity universal joints shown in FIGS. 15, 16, 17, and 18 also have no torque applied to the track groove 36 of the outer joint member 31. The inner flange portion 61 that receives the outer end surface of the outer roller 42 by the centrifugal force in the above is provided. As shown in FIGS. 20, 22, 24, and 26, the dimension between the inner flange portion 61 of the outer joint member 31 and the outer end surface of the outer roller 42 is a, and the outer peripheral surface 60 of the outer roller 42. When the gap between the outer side surface 60a and the outer guide surface 37a of the roller guide surface 37 is b, it is set to a <b. Therefore, the wedge effect does not occur between the outer peripheral surface 60 of the outer roller 42 and the roller guide surface 37, and high low vibration performance can be realized even when no torque is applied.

19 and 20 correspond to the tripod type constant velocity universal joint shown in FIGS. 14 and 15, and FIGS. 21 and 22 correspond to the tripod type constant velocity universal joint shown in FIG. 16, and FIGS. 23 and 24. Corresponds to the tripod type constant velocity universal joint shown in FIG. 17, and FIGS. 25 and 26 correspond to the tripod type constant velocity universal joint shown in FIG. In FIGS. 19, 21, 23, and 25, S indicates a contact portion between the outer peripheral surface 60 of the outer roller 42 and the roller guide surface 37, and S1 indicates the outer end surface of the outer roller 42 and the outer joint member 31. The contact portion with the inner flange portion 61 of the above is shown.

FIG. 27 shows a tripod type constant velocity universal joint provided with an inner flange portion 61 for receiving the outer end surface of the outer roller 42 shown in FIG. 10 and the like, in which the inner roller 41 of the roller mechanism 33 is a tripod member 32 as shown in FIG. The outer diameter surface 39a of the leg shaft 39 is a convex curved surface, and the inner diameter surface 41b of the inner roller 41 is a cylindrical surface.

In FIG. 28, as in the constant velocity universal joint shown in FIGS. 14 to 16, the outer side surface 60a of the outer peripheral surface 60 of the outer roller 42 is a tapered surface (conical surface), and the inner side surface 60b is a tapered surface (conical surface). The outer guide surface 37a of the roller guide surface 37 of the outer joint member 31 is a tapered surface facing the tapered surface of the outer side surface 60a, and the inner guide surface 37b of the roller guide surface 37 of the outer joint member 31 is formed. Is a convex curved surface.

In FIG. 29, as in the constant velocity universal joint shown in FIGS. 21 to 23, the outer side surface 60a of the outer peripheral surface 60 of the outer roller 42 is a convex curved surface, and the inner side surface 60b is a conical surface. Further, the outer guide surface 37a of the roller guide surface 37 is a concave curved surface that fits into the convex curved surface of the outer side surface 60a, and the inner guide surface 37b of the roller guide surface 37 is a convex curved surface.

Therefore, in these tripod type constant velocity universal joints, the outer diameter surface 39a of the leg shaft 39 of the tripod member 32 has a convex curved surface, and in the one shown in FIG. 27, the tripod type constant velocity universal joint shown in FIG. In the one shown in FIG. 28, the same action and effect as those of the tripod type constant velocity universal joint shown in FIG. 14 and the like are exhibited, and in the one shown in FIG. 29, the tripod type constant velocity shown in FIG. 21 and the like are exhibited. It has the same effect as a universal joint.

Each tripod type constant velocity universal joint is provided with a conical surface, a convex curved surface, and / or a concave curved surface on the outer peripheral surface 60 of the outer roller 42, or a tapered surface, a convex curved surface, and / or a concave curved surface on the roller guide surface. May be provided.

Although the embodiment of the present invention has been described above, the present invention is not limited to the embodiment, and various modifications can be made. In each of the embodiments, the roller mechanism 33 includes an inner roller 41 and an outer roller. It is a so-called double roller type having a roller 42. Further, in the tripod type constant velocity universal joint shown in FIGS. 27 to 29, the tripod type constant velocity universal joint of the type shown in FIG. 7 in which the inner diameter surface 41b of the inner roller 41 is a concave curved surface may be used.

31 Outer joint member 32 Tripod member 33 Roller mechanism (roller cassette)
36 Track groove 37 Roller guide surface 37a Outer guide surface 37b Inner guide surface 39 Leg shaft 39a Outer diameter surface 41 Inner roller 41b Inner inner surface 42 Outer roller 60 Outer surface 60a Outer side 60b Inner side 61 Inner collar

Claims (9)

Three axially extending track grooves are formed on the inner peripheral surface, and each of the track grooves has an outer joint member having roller guide surfaces extending in the axial direction on both sides, and three leg shafts protruding in the radial direction. A tripod member and a roller mechanism that is mounted on the leg shaft of the tripod member and can swing swing with respect to the leg shaft are provided, and the outer roller of the roller mechanism is the roller of the track groove of the outer joint member. In a tripod type constant velocity universal joint that slides along a guide surface, the outer peripheral surface of the outer roller of the roller mechanism is orthogonal to the axis of the outer roller and asymmetrically arranged with respect to a plane passing through the center point of the outer roller. It has an outer side surface and an inner side surface, one of the outer side surface and the inner side surface is a convex curved surface, and the other is a conical surface, and the roller guide surface of the track groove is the outer side. It has an outer guide surface for guiding the side surface and an inner guide surface for guiding the inner side surface, and any of the outer guide surface and the inner guide surface is referred to as a convex curved surface on the outer roller side. A tripod type constant velocity universal joint characterized in that it has a concave curved surface that makes line contact and the other guide surface has a convex curved surface that makes point contact with the conical surface on the outer roller side. Three axially extending track grooves are formed on the inner peripheral surface, and each of the track grooves has an outer joint member having roller guide surfaces extending in the axial direction on both sides, and three leg shafts protruding in the radial direction. A tripod member and a roller mechanism that is mounted on the leg shaft of the tripod member and can swing and swing with respect to the leg shaft are provided, and the outer roller of the roller mechanism is the roller of the track groove of the outer joint member. In a tripod type constant velocity universal joint that slides along a guide surface, the outer peripheral surface of the outer roller of the roller mechanism is orthogonal to the axis of the outer roller and is arranged symmetrically with respect to a plane passing through the center point of the outer roller. The outer side surface and the inner side surface are conical surfaces, and the roller guide surface of the track groove is the outer guide surface that guides the outer side surface. The outer guide surface and the inner guide surface have an inner guide surface for guiding the inner side surface, and the outer guide surface and the inner guide surface are the outer guide surface and the outer side surface, and the inner guide surface and the inner side in a torque-free state. The side surfaces are in point contact, and in a torque load state, the outer guide surface and the outer side surface, and the inner guide surface and the inner side surface are in line contact due to elastic deformation, and further, the track groove of the outer joint member is formed. A tripod-type constant-velocity joint characterized in that an inner flange portion is provided to receive the outer end surface of the outer roller by centrifugal force when no torque is applied. Three axially extending track grooves are formed on the inner peripheral surface, and each of the track grooves has an outer joint member having roller guide surfaces extending in the axial direction on both sides, and three leg shafts protruding in the radial direction. A tripod member and a roller mechanism that is mounted on the leg shaft of the tripod member and can swing and swing with respect to the leg shaft are provided, and the outer roller of the roller mechanism is the roller of the track groove of the outer joint member. In a tripod type constant velocity universal joint that slides along a guide surface, the outer peripheral surface of the outer roller of the roller mechanism is orthogonal to the axis of the outer roller and is arranged symmetrically with respect to a plane passing through the center point of the outer roller. The outer side surface and the inner side surface are conical surfaces, and the roller guide surface of the track groove is the outer guide surface that guides the outer side surface. A tapered surface that has an inward guide surface that guides the inner side surface, and that any guide surface of the outer guide surface and the inward guide surface is in line contact with the other side in a torque-free state. The other guide surface is a convex curved surface that makes point contact with the mating side in a torque-free state, and further, the outer roller is formed in the track groove of the outer joint member by the centrifugal force at the time of no torque load. A tripod type constant velocity universal joint characterized by having an inner flange that receives the outer end surface. Three axially extending track grooves are formed on the inner peripheral surface, and each of the track grooves has an outer joint member having roller guide surfaces extending in the axial direction on both sides, and three leg shafts protruding in the radial direction. A tripod member and a roller mechanism that is mounted on the leg shaft of the tripod member and can swing and swing with respect to the leg shaft are provided, and the outer roller of the roller mechanism is the roller of the track groove of the outer joint member. In a tripod type constant velocity universal joint that slides along a guide surface, the outer peripheral surface of the outer roller of the roller mechanism is orthogonal to the axis of the outer roller and asymmetrically arranged with respect to a plane passing through the center point of the outer roller. It has an outer side surface and an inner side surface, and one side surface of the outer side surface and the inner side surface is a conical surface, and the other side surface is a convex curved surface. Has an outer guide surface for guiding the outer side surface and an inner guide surface for guiding the inner side surface, and torque-free load is applied to any of the outer guide surface and the inner guide surface. In the state, it has a cylindrical surface that makes line contact with the mating side, and the other guide surface has a convex curved surface that makes point contact with the mating side in a torque-free state, and further, in the track groove of the outer joint member. A tripod-type constant-velocity joint characterized by providing an inner flange portion that receives the outer end surface of the outer roller by centrifugal force when no torque is applied. Claims 2 to claim that the angle formed by the conical surface of the outer roller and the plane perpendicular to the axis of the outer roller and passing through the center point of the outer roller is set to 60 ° to 80 °. Item 4. The tripod type constant velocity universal joint according to any one of Item 4. The tripod type constant velocity universal joint according to any one of claims 1 to 5, wherein the maximum contact angle of the line contact portion is set to 10 ° to 30 °. The roller mechanism is provided via an inner roller that is externally fitted to the leg shaft of the tripod member, a needle-shaped roller in which a plurality of rollers are arranged along the circumferential direction on the outer peripheral side of the inner roller, and the needle-shaped roller. The tripod type constant velocity universal joint according to any one of claims 1 to 6, further comprising the outer roller arranged on the outer peripheral side of the inner roller. The tripod type constant velocity universal joint according to claim 7, wherein the outer diameter surface cross-sectional shape of the leg shaft of the tripod member is a convex curved surface, and the inner diameter surface of the inner roller is a cylindrical surface. The seventh aspect of claim 7, wherein the outer diameter surface cross-sectional shape of the leg shaft of the tripod member is a convex curved surface, and the inner diameter surface of the inner roller is a concave curved surface that fits into the convex curved surface of the leg shaft. Tripod type constant velocity universal joint.

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