JPH08145071A - Tripod type constant velocity joint - Google Patents

Abstract

PURPOSE: To carry out downsizing and lighten a weight by constituting the shape of the spherical roller guide surface of an outer side roller by a cylindrical surface formed on a center part at a cross sectional surface of a trunnion axial line direction, and the other rotary generating surface provided on the both end part sides holding the cylindrical surface. CONSTITUTION: Relative slide motion in three dimensions direction is generated between the spherical part of the spherical roller 2 of a trunnion 51 and the inner diameter part of an outer side roller 1, the inner diameter part side of the outer side roller 1 consists of the cylindrical surface 11 of a center part at an axial line direction cross sectional surface and the rotary generating surface whose up and down are different from each other while holding the cylindrical surface 11, and three point contact structure is formed between the spherical roller 2 and the outer side roller 1 side, and lubrication is sufficiently carried out in the other than that. A notching part 12 for assembling the spherical roller 2 in the outer side roller 1 is not provided till a position where the cylindrical surface 11 is formed in axial line direction of the outer side roller 1, and it is completed at a rotation generating surface. As a result, force is not applied on a position where the notching part 12 is provided. It is thus possible to carry out downsizing and lighten a mass.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tripod type constant velocity joint used for a driving force transmitting shaft of an automobile or the like.

[0002]

2. Description of the Related Art Generally, in a tripod type constant velocity joint, when the joint portion is used in a state where the joint portion has a crossing angle, it is provided between the guide groove of the outer member and the spherical roller provided on each trunnion of the inner member. Has a problem in that a relative slip phenomenon occurs, which induces an axial thrust force, which in turn causes vibrations in the drive shaft.
In order to solve such a problem, a double type roller is provided between the trunnion and the guide groove.
It has already been devised that only the correct rolling motion is generated between the roller and the guide groove so as to prevent the generation of thrust force and vibration, for example, Japanese Patent Publication No. 57- It is known from Japanese Patent No. 13211.

[0003]

By the way, in the above-mentioned conventional apparatus, for example, as shown in FIG. 9, a spherical roller 20 engaged with the trunnion 50 and the spherical roller 20.
The outer roller 10 which is on the outer side of and is engaged with the guide groove 310
When assembling (fitting) with, the spherical roller 20 is attached to a part of the outer roller 10 on the inner diameter portion 120 side.
Notch 11 having a value larger than the diameter of the spherical surface 210 of
0 must be set. This is because the spherical roller 20 must be incorporated into the outer roller 10 through the cutout 110. However, when a constant velocity joint having such a notch 110 as a part operates, the outer roller 10 and the spherical roller 20 relatively move in the circumferential direction, and the position of the notch 110 becomes
It may coincide with the torque transmission direction. In such a state (positional relation), the outer roller 10
At the end portion 190 of the cutout portion 110 in the inner diameter portion 120, stress concentration occurs. In order to solve such a problem, the notch 1 is arranged so that the position of the notch 110 does not coincide with the torque transmission direction.
It is necessary to fix the position of 10.

For example, in the one disclosed in Japanese Utility Model Laid-Open No. 64-6425, a detent flange is provided on an outer roller which engages with a spherical roller. However, by providing such a flange, the roller (outer roller) that engages with the spherical roller becomes large and the tripod type constant velocity joint becomes large in size. Then, eventually, the weight (mass) of the tripod type constant velocity joint is increased. In order to solve such a problem, it is an object to provide a small tripod type constant velocity joint in which it is not necessary to provide a rotation stopping flange or the like on the roller or the like that engages with the spherical roller. Purpose (problem) of the present invention
Is.

[0005]

In order to solve the above-mentioned problems, the following measures are taken in the present invention. That is, according to the first aspect of the invention, the outer member has a cylindrical shape, and has an outer member having a plurality of guide grooves extending in the axial direction on the inner diameter side thereof and coaxially inside the outer member. An inner member having a plurality of trunnions that are arranged and project into the guide groove, a spherical roller that is rotatably attached to each of the trunnions, and has an outer peripheral surface having a spherical shape,
The outer surface of the spherical roller is mounted so as to be capable of relative rotational movement with respect to the spherical roller,
An outer roller having a spherical roller guide surface in contact with the spherical surface of the spherical roller is provided on the inner side, and while maintaining constant velocity rotational motion transmissibility between the outer member and the inner member, angular displacement of both members and In a tripod type constant velocity joint capable of allowing relative displacement in the axial direction, the shape of the spherical roller guide surface of the outer roller is defined by a cylindrical surface formed in the central portion of the trunnion in the axial direction cross section and the cylindrical surface. The surface is sandwiched between the other rotation generating surfaces provided on both ends of the surface.

Further, according to a second aspect of the present invention, a notch portion for incorporating the spherical roller in a part of the inner side of the outer roller having the above-mentioned structure on the inner diameter side, and part of the other rotation generating surface. It was decided to adopt a configuration in which

[0007]

By adopting the above construction, the following effects are exhibited in the present invention. That is, a spherical roller and an outer roller are assembled on the axis of each trunnion radially provided on the inner member, and the outer roller in such a state is guided on the inner diameter side of the outer member. By being mounted in the groove, a slide type tripod type constant velocity joint is formed. When the constant velocity joint configured as described above is used in a state where it is bent at the joint portion, that is, in a state where it has a crossing angle, a three-dimensional joint is formed between the spherical roller and the outer roller. Relative motion in the direction will be formed. And further,
Between the outer roller and the guide groove, rolling motion in a two-dimensional direction along the direction of the guide groove occurs.

As a result, the swinging motion of the inner member including the trunnion is completely processed between the spherical roller and the outer roller, and only the rolling motion occurs between the outer roller and the guide groove. become. Therefore, even if torque is transmitted between the inner member and the outer member in a state where there is a crossing angle, an abnormal sliding phenomenon does not occur between the guide groove and the outer roller. As a result, the generation of vibrations due to the generation of thrust force will be suppressed.

Further, in such an operation, a relative sliding motion in a three-dimensional direction occurs between the spherical portion of the spherical roller and the inner diameter portion of the outer roller, but the inner diameter portion side of the outer roller has its axis line. In a cross section in the direction, it is composed of a cylindrical surface formed in the central portion and another rotation generating surface formed above and below the cylindrical surface, and between the spherical roller and the outer roller. A three-point contact structure will be formed. The oil is sufficiently lubricated at a portion other than these three-point contact portions, and there is no risk of oil shortage or the like due to sliding motion.

Further, the cutout portion for incorporating the spherical roller in the outer roller is not provided up to the point of forming the cylindrical surface in the axial direction of the outer roller, and is provided at the lower end portion or the upper end portion. The structure ends at another (other) rotational creation surface that is formed. Therefore, even if the joint portion is used in a bent state and the load caused by the transmission torque acts between the spherical surface of the spherical roller and the inner diameter portion of the outer roller, almost no force is transmitted on the cylindrical surface. It is carried out, and no force (load) is applied to the place where the notch is present. Therefore, problems such as the influence of the notch effect and stress concentration on the end face of the notch, which have been feared in the conventional one, do not occur. Therefore, it is not necessary to separately provide a rotation stopping flange or the like on the outer roller or the like that is a roller that engages with the spherical roller. As a result, it is possible to reduce the size and weight of the roller, and further reduce the size and weight of the constant velocity joint.

[0011]

Embodiments of the present invention will be described with reference to FIGS. As shown in FIG. 1, the configuration of the present embodiment is composed of a cylindrical member, and has a housing-shaped outer member 3 having three guide grooves extending in the axial direction on the inner diameter side, and the outer member. And an axial inner member 5 radially arranged with three trunnions 51 provided so as to project into the three guide grooves 31. It is based on that.

In such a basic structure, the outer member 3 is connected to the power unit side such as an engine through the flange portion 33 and the like. As shown in FIGS. 1 and 2, the inner member 5 includes a spider member 55 that radially has three trunnions 51 that engage with the outer member 3 side to form a joint.
The spider member 55 is spline-connected to the shaft 52, which is connected to a wheel or the like.

The guide groove 3 having these structures is provided.
The engaging portion between 1 and the trunnion 51 has a structure as shown in FIGS. 3 and 4. That is, the spherical roller 2 is attached to each trunnion 51 provided on the radiation of the spider member 55 via the needle bearing 4 so as to be movable in the axial direction of the trunnion 51. The outer roller 1 is fitted to the spherical surface 21 formed on the outer circumference of the spherical roller 2 so that the outer roller 1 can perform relative rotational movement and oscillating movement.
The assembled (assembled) in such a state is mounted in the three guide grooves 31 of the outer member 3 as shown in FIGS. 1 and 2, and the slide type tripod constant velocity joint is mounted. Are formed.

In such a structure, the outer roller 1 mounted on the outer side of the spherical roller 2 is shown in FIGS.
As shown in FIG. 5, the inner diameter portion basically has a cylindrical surface, and the outer diameter portion has a convex surface, which is in the shape of a ball.
The outer diameter portion (outer diameter surface) 15 is engaged with the guide groove 31 of the outer member 3 so that only the rolling movement is possible in the guide groove 31. Further, as shown in FIGS. 6 to 8, the inner diameter portion has an axial direction (trunnion 5
1 has a cylindrical surface 11 in the central portion, and a rotation generating surface 1 composed of a straight line or a quadratic curve on both upper and lower end sides of the cylindrical surface 11 with the cylindrical surface 11 in between.
3, 14 is provided. Here, the rotation generating surfaces 13 and 14 are the spherical surface 21 of the spherical roller.
May be a curved surface corresponding to the above, or may be a linear tapered surface. In short, the spherical roller 2 is inserted (mounted) in the inner diameter portion of the outer roller 1 as shown in FIG.
In this case, the spherical roller 2 and the outer roller 1 may be in contact with each other at three points in the axial direction. And, preferably, the three-point contact is made by a line contact. And further, the above 3
As shown in FIG. 6, annular oil grooves 18 and 18 'are provided where the two surfaces are connected.

7 and 8 where the rotation generating surfaces 13, 14 other than the cylindrical surface 11 of the inner diameter portion are formed.
A notch 12 as shown in is provided in the diametrical direction.
As shown in FIGS. 5 and 8, the notch 12 has an oval shape in which the opening shape is a width across flats, and the maximum notch length (L) is the spherical roller. Two
It is formed to be slightly larger than the value of the diameter (d) of the spherical surface 21 (see FIG. 4). Because
This is because the spherical roller 2 is adapted to be incorporated into the inner diameter portion of the outer roller 1 via the cutout portion 12. Further, the diameter of the cylindrical surface 11 formed on the inner diameter portion of the outer roller 1 is a value of d or a value slightly larger than d. In addition, in such a structure, the said cylindrical surface 11 and the rotation generation surface 1
3, 14 form a spherical roller guide surface.

The operation and the like of this embodiment having such a configuration will be described. The operation of this embodiment is basically the same as that described in the above section. That is, the present tripod type constant velocity joint forms a double roller type slide joint, but the rotational torque is transmitted as shown in FIG. 2 in a state where the joint portion has a crossing angle. However, since the rolling motion is formed between the outer member 3 and the inner member 5, the thrust force is not generated, so that the vibration or the like due to the thrust force does not occur.

That is, the spherical roller 2 rotatably attached to the trunnion 51 and the guide groove 3 of the outer member 3.
Between the outer roller 1 that moves in the inner part 1 and the outer roller 1, it is possible to perform a relative rotational motion and a relative rocking motion in a three-dimensional direction. Therefore, the neck of the inner member 5 having the trunnion 51 is formed. The swinging movement is handled by the relative movement between the spherical roller 2 and the outer roller 1.
The movement (movement) of the outer roller 1 in the guide groove 31 is treated as a rolling movement, and a prying phenomenon such as a sliding movement does not occur in the guide groove 31. Therefore, the outer roller 1 moves smoothly in the guide groove 31.

Further, a cutout 12 for mounting the spherical roller 2 is provided in the inner diameter portion of the outer roller 1, and the cutout 12 is separated from the central portion as shown in FIG. It is provided only near the end, and the spherical roller 2 to the outer roller 1 through the trunnion 51.
Even when torque is transmitted to the notch 12,
Is not the main pressure receiving surface on which torque is transmitted. That is, as shown in FIG. 4, the main force transmitting portion between the spherical surface 21 of the spherical roller 2 and the inner diameter portion of the outer roller 1 is the portion of the cylindrical surface 11 as far as the outer roller 1 is concerned. . Therefore, even if the torque is transmitted, stress concentration or the like does not occur in the cutout portion 12. Therefore, it is not necessary to provide a flange or the like for preventing the outer roller 1 from rotating along with the conventional one.

The contact portion between the spherical surface 21 of the spherical roller 2 and the inner diameter portion of the outer roller 1 basically has a three-point contact structure as shown in FIG. Therefore, a gap (E) as shown in FIG. 3 is formed between the three contact points formed on the inner diameter side of the outer roller 1, and the gap (E) forms an oil groove. Will be done. By forming this oil groove, lubricity can be improved by enclosing grease or the like between the inner diameter portion of the outer roller 1 and the spherical surface 21 of the spherical roller 2.
As a result, even if relative movement occurs, problems such as running out of oil do not occur. In this embodiment,
The oil grooves 18, 18 'are positively placed at the place where this gap is generated.
Since there is no oil supply, there is no risk of problems such as running out of oil, which has been a concern in the prior art.

In the above structure, the guide groove 31 of the outer member 3 and the outer diameter portion 15 of the outer roller 1 are engaged with each other by the uneven portion formed by the two tapered surfaces as shown in FIG. And the outer diameter portion 15 of the outer roller 1
Is only capable of rolling motion in the guide groove 31. That is, at this contact portion,
Since only one exercise is surely taken and the other exercises are not taken together, the life can be extended. In addition to the above, the engaging portion between the guide groove 31 and the outer diameter portion 15 may have an uneven curved surface engaging structure.

Further, in the present embodiment, the example applied to the double roller type tripod type constant velocity joint is shown, but the present invention is not limited to this, and the axial direction of the trunnion is not limited thereto. It is also applicable to a triple roller type tripod type constant velocity joint in which each roller is responsible for relative movement, rotational movement about the axis of the trunnion, and swing movement of the trunnion. That is,
The present invention can be applied to all spherical fittings that allow the swing motion of the trunnion.

[0022]

According to the present invention, the outer member is formed of a cylindrical housing-shaped member and has a plurality of guide grooves extending in the axial direction on the inner diameter side thereof, and the outer member is coaxial with the outer member. Are arranged in a manner, an inner member having a plurality of trunnions protruding into the guide groove, a spherical roller rotatably attached to each of the trunnions, the outer peripheral surface of which has a spherical shape, It is attached to the outside of the spherical roller so as to be capable of relative movement in three dimensions with respect to the spherical roller,
An outer roller having a spherical roller guide surface that abuts the spherical surface of the spherical roller is provided inside thereof, and the shape of the spherical roller guide surface of the outer roller is formed in the central portion in the axial cross section of the trunnion. Since it has a cylindrical surface and rotation generating surfaces provided above and below the cylindrical surface, the relative movement between the spherical roller and the outer roller with respect to the swinging motion of the trunnion. As a result, the rolling motion is generated between the outer roller and the guide groove, and the occurrence of vibrations due to slippage or twisting is suppressed. It was Moreover, the spherical roller and the outer roller have a three-point contact structure, and a gap is formed between the contact portions, and lubricating oil such as grease is sealed in this gap to improve lubrication performance. Is now possible. This makes it possible to prevent seizure and the like due to running out of lubricating oil.

Further, the notch for incorporating the spherical roller into the outer roller is provided only at the end of the outer roller, and is not provided up to the central cylindrical surface. , Even when the force is transmitted from the trunnion to the outer roller via the spherical roller,
The force is transmitted mainly at the cylindrical surface, not at the notch. Therefore, since the presence of the cutouts eliminates the problem of stress concentration and the like, it is not necessary to fix the position of the cutouts, and a rotation stopping flange or the like is provided on the outer roller engaging with the spherical roller. There is no need to install it. Therefore, the outer roller can be downsized, and the entire constant velocity joint can be downsized and lightened.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing the overall configuration of the present invention.

FIG. 2 is a cross-sectional view showing the overall structure of the present invention.

FIG. 3 is a diagram showing a general cross-sectional shape around a spherical roller and an outer roller according to the present invention.

FIG. 4 is a view showing a cross-sectional shape around a spherical roller and an outer roller according to the present invention and showing a form of a cutout portion.

FIG. 5 is a plan view showing the outer appearance of an outer roller according to the present invention.

6 is a view showing a general cross-sectional shape of the outer roller according to the present invention, which is a cross-sectional view taken along the line AA of FIG.

7 is a vertical cross-sectional view of the outer roller according to the present invention, which is a BB cross-sectional view of FIG.

8 is a cross-sectional view of the outer roller according to the present invention, which is a CC cross-sectional view of FIG.

FIG. 9 is a partial cross-sectional view showing a configuration of a tripod type constant velocity joint according to a conventional example.

[Explanation of symbols]

 1 Outer Roller 11 Cylindrical Surface 12 Notch 13 Other Rotational Generation Surface 14 Other Rotational Generation Surface 15 Outer Diameter (Outer Diameter) 18 Oil Groove 18 'Oil Groove 2 Spherical Roller 21 Spherical 22 Inner Diameter 3 Outer Member 31 Guide Groove 33 Flange portion 4 Needle bearing 5 Inner member 51 Trunnion 52 Shaft 55 Spider member

Claims (2)

[Claims] 1. An outer member having a cylindrical shape and having a plurality of guide grooves extending in the axial direction on the inner diameter side thereof, and arranged coaxially inside the outer member, and An inner member having a plurality of trunnions provided so as to project into the guide groove, a spherical roller rotatably attached to each of the trunnions and having an outer peripheral surface having a spherical shape, and a spherical roller of the spherical roller. An outer roller, which is mounted on the outer side so as to be capable of relative movement with respect to the spherical roller, and has an inner side outer roller having a spherical roller guide surface in contact with the spherical surface of the spherical roller. In a tripod type constant velocity joint capable of allowing angular displacement of both members and relative displacement in the axial direction while maintaining constant-velocity rotational motion transmission with the inner member, The spherical roller guide surface of the outer roller has a configuration in which, in the axial section of the trunnion, a cylindrical surface formed at the center and another rotation provided on both end sides with the cylindrical surface interposed therebetween. A tripod type constant velocity joint characterized by being composed of a creation surface and. 2. The tripod type constant velocity joint according to claim 1, wherein a notch for incorporating the spherical roller is provided on a part of the other rotation generating surface on the inner diameter side of the outer roller.