JPH11182571A - Constant velocity joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constant velocity joint capable of reducing the increase in the coefficient of friction at a contact point of an inner joint member with a cage, and suppressing the increase in the slide resistance and the thrust force even when the torque is loaded in the high slide zone, and the small vibration such as the vibration in the idling condition is given. SOLUTION: An inner circumferential surface 17 of a cage 13 of a constant velocity joint connects a cylindrical surface 17a having the axial length A of a center part to a partial spherical area 17b located on each side. The centers O2-O5 of curvature and the radii R2-R5 of curvature of partial spherical surfaces 22, 23, 24, 25 to constitute each partial spherical area 17b are set so that inner joint members 12 are allowed simultaneously to abut on its outer circumferential surface 18 when they are moved in the axial direction. The load is divided by the simultaneous abutting of the partial spherical surfaces 22, 23 or 24, 25 on the partial spherical area 17b of the cage 12, and the load on the abutting part is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant velocity joint.

[0002]

2. Description of the Related Art Conventionally, a constant velocity joint disclosed in Japanese Utility Model Publication No. Sho 63-2665 is known as a constant velocity joint used in an automobile. As shown in FIG. 5, the inner peripheral surface of the cage 1 of this constant velocity joint is formed at a central portion in the axial direction, and has a cylindrical surface 2 having an arbitrary axial length, and a cylindrical surface 2 on both sides of the cylindrical surface 2. The inner joint member 3 includes an outer curved surface 4 and a partial spherical surface 5 having the same radius r. With this configuration, cage 1
An axial gap is formed between the inner joint member 3 and the inner joint member 3.

[0003] By providing the axial gap on both sides of the cylindrical surface 2 at the center of the cage 1 as described above,
Even when the axial vibration is input, the inner joint member 3 and the cage 1 can relatively move, so that the slide resistance in the constant velocity joint can be reduced. Hereinafter, an area where the slide resistance is small is called a low slide area, and an area where the slide resistance is large is called a high slide area. In the above case, the low slide region is a region where the inner joint member 3 slides on the cylindrical surface 2, and the high slide region (a region where the slide resistance is large) is a region where the inner joint member 3 slides on the partial spherical surface 5. It is.

[0004]

In the above configuration, when a torque is applied and a minute vibration such as vibration during idling is applied, fretting occurs at a contact point between the inner joint member 3 and the cage 1. I do. This fretting increases the coefficient of friction at the point of contact and causes an increase in slide resistance and thrust force.

[0005] Particularly, in the high sliding region where the inner joint member 3 slides on the partial spherical surface 5, the sliding resistance and the thrust force are further increased. An object of the present invention is to reduce an increase in a coefficient of friction at a contact point between an inner joint member and a cage even when a torque is applied in a high slide range and a minute vibration such as vibration during idling is applied. Accordingly, it is an object of the present invention to provide a constant velocity joint capable of suppressing an increase in slide resistance and thrust force.

[0006]

According to a first aspect of the present invention, an inner joint member is provided on one of the two intersecting shafts, and a cylindrical outer joint member is provided on the other. Ball grooves formed on each of the outer and inner peripheral surfaces, a plurality of torque transmitting balls disposed between the ball grooves, and balls for fitting between the inner and outer joint members to hold the torque transmitting balls A cage having a holding window formed therein, wherein a predetermined position in the axial direction of the inner circumferential surface of the cage is defined as a center, and partial spherical regions are formed on both sides in the axial direction from the center. In the constant velocity joint in which the joint member is movable, at least one of the partial spherical regions located on both sides in the axial direction from the center is formed by connecting a plurality of partial spherical surfaces having different radii of curvature or centers of curvature. And a plurality of partial spherical surfaces in the partial spherical region, a constant velocity joint characterized by being arranged so as to be able to simultaneously abut against the inner joint member when the inner joint member moves in the axial direction. It is an abstract.
According to a second aspect of the present invention, in the first aspect, each of the partial spherical regions includes a constant velocity joint composed of two partial spherical surfaces.

[0007] The third aspect of the present invention is the first or second aspect.
In the above, the partial spherical surfaces constituting each partial spherical region are characterized by constant velocity joints having different radii of curvature. According to a fourth aspect of the present invention, in the first or second aspect, the partial spheres constituting each of the partial sphere regions have a constant velocity joint having different centers of curvature.

[0008] The invention of claim 5 is the invention of claims 1 to 4.
In any one of the above, the center of the predetermined position in the axial direction of the inner circumferential surface of the cage is characterized by a constant velocity joint formed on a cylindrical surface.

[0009] The invention of claim 6 is the invention of claims 1 to 4.
In any one of the above aspects, at the center of the predetermined position in the axial direction of the inner circumferential surface of the cage, the two partial spherical regions are characterized by a constant velocity joint which is directly connected smoothly.

According to the first aspect of the present invention, when an axial force acts on the inner joint member in the partial spherical area of the inner peripheral surface of the cage, the inner joint member is moved to the inner periphery of the cage. In the partial spherical surface area of the surface, at least two of the plurality of partial spherical surfaces simultaneously abut. As a result, the load is divided at at least two contact points, so that the load per point is reduced. Also, by contact at two or more places,
A space is formed between the contact points, and this space has the same effect as the oil groove, and the running out of the lubricant put in the constant velocity joint is suppressed.

According to the second aspect of the present invention, each partial spherical region is constituted by two partial spherical surfaces.
Has the effect of According to the third aspect of the present invention, the partial spherical surfaces constituting the partial spherical regions have different radii of curvature from each other, so that the effect of the first or second aspect is achieved.

According to the fourth aspect of the present invention, the partial spherical surfaces constituting each partial spherical region have different centers of curvature from each other, thereby achieving the effect of the first or second aspect.
According to the fifth aspect of the present invention, even when the center of the predetermined position in the axial direction of the inner circumferential surface of the cage is formed on a cylindrical surface,
The operation according to any one of claims 4 to 4 is achieved.

According to the sixth aspect of the present invention, the function of any one of the first to fourth aspects can be achieved even if the two partial spherical regions are directly connected at the center of the predetermined position in the axial direction of the inner peripheral surface of the cage. Play.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment in which the present invention is embodied in a constant velocity joint used in an automobile will be described below with reference to FIGS.

FIG. 1 is a sectional view showing the structure of a constant velocity joint, and FIG. 2 is a sectional view of a main part of the constant velocity joint. The constant velocity joint 10 includes an outer joint member 11, an inner joint member 12,
A cage 13 and a torque transmission ball 14 are provided. The outer joint member 11 has a cylindrical shape with a bottom and a drive shaft 8.
, While the inner joint member 12 is connected to the driven shaft 9.
Are spline-connected. The outer joint member 11 has a linear guide groove 1 along the axial direction with respect to the cylindrical inner peripheral surface 15.
6 are formed. The inner joint member 12 is a cage 1
3 is a partially spherical outer peripheral surface 18 for guiding the inner peripheral surface 17
It has. The outer peripheral surface 18 forms a uniform arc having a radius of curvature r when viewed in a cross section along the axial direction, and the center of curvature is at any point O located on the axis L of the driven shaft 9.
It is set to 1. The axis L is the inner joint member 12.
Coincides with the axis of. The outer joint member 1 is provided on the outer peripheral surface 18.
The one guide groove 16 forms a ball groove 19 which forms a ball track.

The cage 13 has ball holding windows 20 for accommodating the torque transmitting balls 14 at equal intervals in the circumferential direction.
Are formed (six in this embodiment). The outer peripheral surface of the cage 13 is the inner peripheral surface 15 of the outer joint member 11.
Is formed in the shape of a truncated cone having a partially protruding spherical surface 21 which is slidably fitted along the axial direction with respect to. The center of curvature forming the partial salient sphere 21 is located at a point O6 located on the axis L of the driven shaft 9 and separated from the center of curvature O1 by a certain distance.

As shown in FIG. 2, an inner peripheral surface 17 of the cage 13 connects a cylindrical surface 17a having an axial length A at the center thereof and partial spherical regions 17b located on both sides in the axial direction. It is formed with. Each partial spherical surface region 17b is composed of two partial spherical surfaces 22, 23, 24, and 25.

Partial spherical surface 22 of one partial spherical region 17b
Is defined by the center of curvature O2 which defines the cylindrical surface 17a and the partial spherical region 17b, and which is radially shifted from the axis L on a line M1 perpendicular to the axis L of the driven shaft 9.
It is located at a position offset by a distance of two.
The cylindrical surface 17a and the partial spherical surface 22 are smoothly connected.

The center of curvature O3 forming the partial spherical surface 23 of the one partial spherical region 17b defines the cylindrical surface 17a and the partial spherical region 17b, and is on a line M2 orthogonal to the axis L of the driven shaft 9. In the example, the position is offset from the axis L by a distance D3 in the radial direction. The centers of curvature O2 and O3 pass through the center of the cylindrical surface 17a (the two equally-divided positions) and are located at right and left opposite positions across a reference line MO orthogonal to the axis L at the point O as shown in FIG. Are located.

The center of curvature O4 forming the partial spherical surface 24 of the other partial spherical region 17b is located on the line M2.
It is arranged at a position offset from the axis L by a distance of D4 in the radial direction. The center of curvature O5 forming the partial spherical surface 25 of the other partial spherical surface region 17b is disposed on the line M1 at a position offset from the axis L by a distance D5 in the radial direction.

The centers of curvature O4 and O5 are arranged at positions opposite to each other with respect to the reference line MO as shown in FIG. The curvature radiuses R2 and R3 of the partial spherical surfaces 22 and 23 and the offset amounts D2 and D3 from the axis L in one partial spherical region 17b are determined by the inner joint member 12 in the axial direction (rightward in FIG. 2). The outer peripheral surface 18 is set so as to simultaneously contact the two partial spherical surfaces 22 and 23 (see point P in FIG. 3).

In the other partial spherical region 17b, the radii of curvature R4, R5 of the partial spherical surfaces 24, 25 and the axis L
Offset amounts D4 and D5 from the inner joint member 1
When 2 moves in the axial direction (left direction in FIG. 2),
The outer peripheral surface 18 is set so as to simultaneously contact both partial spherical surfaces 24 and 25.

The curvature radii R2 to R5 and the offset amount D
2 to D5 are determined by the frequently used joint angles of the vehicle using the constant velocity joint 10. In this embodiment, R2 = R4, R3 = R5, D2 = D
4, D3 = D5.

Further, each of the radii of curvature R2 to R5 has a radius r.
Larger than. As a result, an axial gap G1 is formed between the inner joint member 12 and the cage 13 to allow the inner joint member 12 to be displaced in the axial direction.

Further, as shown in FIG.
A gap G2 having an appropriate interval is formed between the torque transmission ball 14 and the zero. The gap G2 is desirably provided at least in the axial direction among the axial direction and a direction orthogonal to the axial direction. This gap G2 releases at least the axial restraint of the torque transmitting ball 14 by the ball holding window 20, and the torque transmitting ball 14
5 to 5 so that the influence at the time of collision between
It is preferable to set it in the range of 0 μm.

The gap G2 may be zero as long as the restraint of the torque transmitting ball 14 can be released. However, in terms of manufacturing control, it is certain that the gap G2 is 5 μm or more. On the other hand, if the gap G2 exceeds 50 μm, the hitting sound at the time of collision between the torque transmitting ball 14 and the cage 13 increases, and the impact at the time of collision impairs the stability of the cage 13 and promotes vibration. Therefore, the thickness is preferably 50 μm or less.

In this embodiment, the outer joint member 11 of the constant velocity joint 10 is filled with grease (not shown) as a lubricant. Now, the operation of the constant velocity joint 10 having the above configuration will be described.

When a torque is applied to the constant velocity joint 10 and micro vibration such as vibration during idling is applied, the inner joint member 12 is moved into two partial spherical surfaces in the partial spherical region 17b in the high sliding range. Abut. In FIG. 3, the partial spherical surface 22 of one partial spherical region 17b,
23 shows a state in which the inner joint member 12 is in contact with both of them. In this state, the inner joint member 12 comes into contact with the partial spherical region 17b at two points P shown in FIG. 3, so that the load is divided. As a result, the contact pressure at the contact point is lower than in the conventional case where the contact point is in one place.

In the other partial spherical region 17b,
Similarly, when the inner joint member 12 moves and comes into contact with the inner joint member 12, the inner joint member 12 comes into contact with both of the partial spherical surfaces 24 and 25. For this reason, similarly, the contact pressure at the contact point is lower than that in the case where the contact pressure is conventionally at one point.

Therefore, the constant velocity joint 10 having the above configuration has the following advantages. (1) Unlike the conventional case where the inner joint member is in contact with the partial spherical surface at one point in the high slide range, the inner joint member 12 comes into contact with the two partial spherical surfaces. Can be lowered. As a result, the occurrence of fretting on the inner peripheral surface 17 of the cage 13 can be suppressed, so that the friction coefficient does not increase and the thrust force does not increase.

(2) Also, as described above, the inner joint member 1
Since the two contact two points, a gap G is formed between the contact points, for example, as shown in FIG. 3, between two P points. Therefore, the gap G has the same effect as the oil groove. . That is, since the constant velocity joint 10 is filled with grease, the grease enters the gap G, and the grease can be prevented from running out.

(3) In this embodiment, unlike the configuration of the prior art (constant velocity joint disclosed in Japanese Utility Model Publication No. 63-2665), the radii of curvature R2 to R5 are larger than the radius r. For this reason, since the radius of curvature of the partial spherical region 17b of the cage 13 is large, the slide resistance can be reduced.

(4) In the present embodiment, a gap G2 is formed at least in the axial direction between the torque transmitting ball 14 and the wall surface of the ball holding window 20 of the cage 13. Therefore, when vibration is applied from the engine side in a state where a torque is applied, the torque transmission ball 14 can roll freely, and the axial displacement between the outer joint member 11 and the inner joint member 12 and The slide resistance inside the joint at the time of angular displacement can be made very small. Further, the generated vibration is absorbed by the gaps G1 and G2, and transmission to the vehicle body can be prevented.

(5) From the above, as in the case where the vehicle is stopped with the torque applied (for example, the vehicle is stopped with the shift lever set to the D range in an automatic transmission (AT) vehicle), Slide resistance caused by idle vibration of the motor can be reduced. (Second Embodiment) Next, a second embodiment will be described with reference to FIG.

In this embodiment, unlike the first embodiment, the cylindrical surface 17a is omitted. Hereinafter, the same configuration as the configuration of the above-described embodiment or the corresponding configuration is denoted by the same reference numeral, and the description will be focused on the difference.

FIG. 4 is a schematic view of the cage 13, and the magnitude of each parameter such as the radius of curvature is exaggerated. Assuming that a point at a certain distance from the center of curvature O6 on the axis L is O, at the intersection between the reference line MO passing through the point O and orthogonal to the axis L and the inner peripheral surface 17, one of the partial spherical regions 17b The partial spherical surface 22 and the partial spherical surface 24 of the other partial spherical surface 17b are smoothly and directly connected. The curvature center O2 of the partial spherical surface 22 is separated from the axis L by an offset amount D2 on the reference line MO. The center of curvature O4 of the partial spherical surface 24
Is the offset amount D from the axis L on the reference line MO.
4 away. The radii of curvature of the two partial spherical surfaces 22 and 24 are R4> R2, and the offset amount is D4> D.
2, different from each other. The relationship between the radii of curvature of the partial spheres 21 and 24, the relationship between the centers of curvature, and the relationship between the radius of curvature and the center of curvature can be obtained in advance by experimental trial production or the like.

That is, by making the center of curvature of the partial spherical surfaces 22 and 24 and the offset amount from the axis L different from each other, even if the cylindrical surface 17a of the first embodiment is omitted, the low sliding area is reduced to the two partial spherical surfaces 22. , 24 are obtained.

The center of curvature O3 of the partial spherical region 23 of the one partial spherical region 17b is separated from the axis L by an offset D3 on a line M3 which is axially separated from the reference line MO by an offset D10. I have. The center of curvature O5 of the partial spherical surface 25 is separated from the axis L by an offset D5 on a line M4 separated from the reference line MO by an offset D11 on the side opposite to the axis M3 in the axial direction.

The curvature radii R2, R3 and the offset amounts D2, D3, D10, D11 of the partial spherical surfaces 22, 23 in one partial spherical surface region 17b are determined by the inner joint member 12 in the axial direction (right in FIG. 4). Direction), the outer peripheral surface 18 is set so as to simultaneously contact the two partial spherical surfaces 22 and 23.

Further, the curvature radii R4, R5 and the offset amounts D4, D5, D10, D11 of the partial spherical surfaces 24, 25 in the other partial spherical region 17b are determined in accordance with the axial direction of the inner joint member 12 (in FIG. The outer peripheral surface 18 is set so as to simultaneously contact the partial spherical surfaces 24 and 25 when the outer peripheral surface 18 moves to the left (in the left direction).

The curvature radii R2 to R5 and the offset amount D
2 to D5, D10, and D11 are constant velocity joints 10;
Is determined by the frequently used joint angle of the vehicle that uses.

In this embodiment, as in the first embodiment, each of the radii of curvature R2 to R5 is larger than the radius r. As a result, an axial gap allowing the axial displacement of the inner joint member 12 is formed between the inner joint member 12 and the cage 13.

In the constant velocity joint 10 having the above-described structure, torque is applied to the constant velocity joint 10 in the same manner as in the first embodiment. Inner joint member 1 in slide area
2 comes into contact with the two partial spherical surfaces in the partial spherical region 17b.

As a result, the contact pressure at the contact point is lower than that in the conventional case where one contact is made. Therefore, the constant velocity joint 10 having the above configuration has the following advantages. (1) The same effects as (1) to (5) of the first embodiment can be obtained.

(2) In this embodiment, the partial spherical surface 2
The radius of curvature R2, R4 of the partial spherical surface 22,
By making the amount of offset from the center of curvature of 24 and the axis L different from each other, the cylindrical surface 1 of the first embodiment can be changed.
Even if 7a is omitted, the low sliding area has both partial spherical surfaces 22,2.
4 was obtained. For this reason, unlike the first embodiment, even if the cylindrical surface 17a is omitted,
The partial spherical surfaces 22 and 24 can be set to a low sliding area. As a result, the slide resistance in the low slide area can be made constant and small.

The present invention is not limited to the above embodiment, but may be implemented as follows. (1) In the first embodiment and the second embodiment, each partial spherical region is configured by two partial spherical surfaces, but may be formed by three or more partial spherical surfaces. In this case, the center of curvature and the radius of curvature are set so that three or more partial spherical surfaces can come into contact at the same time when the inner joint member moves to the high slide region.

(2) Of the partial spherical regions 17b on both sides of the first embodiment, the second embodiment or the above (1), only the partial spherical surfaces of one partial spherical region 17b are simultaneously formed on the outer peripheral surface of the inner joint member. , And the respective partial spherical surfaces of the other partial spherical region 17b may not be in contact at the same time. In this case, the other partial spherical surface region may be constituted by a single partial spherical surface.

Here, in addition to the technical ideas described in the claims, the technical ideas grasped by the above-described embodiments are listed below together with their effects. (1) In claim 1, partial spherical regions on both sides of the partial spherical region located on both sides in the axial direction from the center are formed by connecting a plurality of partial spherical surfaces having at least one of different radii of curvature or centers of curvature. Further, at least two of the plurality of partial spherical surfaces in the partial spherical region are arranged so as to be able to simultaneously contact the inner joint member when the inner joint member is moved in the axial direction. Joint. By doing so, the load is divided at at least two contact points in both partial spherical regions, so that the load per one portion is reduced. In addition, a space is formed between the contact points due to the contact at two or more places, and this space has the same effect as the oil groove, and the running out of the lubricant put in the constant velocity joint is suppressed.

[0049]

As described above in detail, according to the first aspect of the present invention, even when a torque is applied in a high slide range and a minute vibration such as an idling vibration is applied,
The increase in the coefficient of friction at the contact point between the inner joint member and the cage can be reduced, and as a result, the increase in slide resistance and thrust force can be suppressed.

According to the second aspect of the present invention, the effect of the first aspect is achieved by forming each partial spherical area from two partial spherical surfaces. According to the third aspect of the present invention, the partial spherical surfaces constituting each partial spherical surface region have different radii of curvature from each other, so that the effect of the first or second aspect is achieved.

According to the fourth aspect of the present invention, the partial spherical surfaces constituting each partial spherical surface region have different centers of curvature, thereby achieving the effect of the first or second aspect.
According to the fifth aspect of the present invention, when the center of the predetermined position in the axial direction of the inner circumferential surface of the cage is formed in a cylindrical surface, a low sliding area can be obtained.

According to the sixth aspect of the present invention, the two partial spherical regions are directly connected to each other at the center of the predetermined position in the axial direction of the inner circumferential surface of the cage. It works.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the structure of a constant velocity joint according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part of the constant velocity joint.

FIG. 3 is an enlarged schematic diagram of a main part in the same manner.

FIG. 4 is a schematic view of a cage according to a second embodiment.

FIG. 5 is a sectional view of a main part of a conventional constant velocity joint.

[Explanation of symbols]

10: constant velocity joint, 11: outer joint member, 12: inner joint member, 13: cage, 14: torque transmitting ball,
15: cylindrical inner peripheral surface, 16: guide groove, 17: cage 13
Inner peripheral surface, 17a: cylindrical surface, 17b: partial spherical region, 1
8: outer peripheral surface of inner joint member 12, 19: ball groove, 20
... Ball holding window, 21 ... Partially protruding spherical surface, 22,23,2
4, 25: partial spherical surface, D2, D3, D4, D5: offset amount, R2, R3, R4, R5, r: radius.

Claims (6)

[Claims] An inner joint member is provided on one of two intersecting shafts, and a cylindrical outer joint member is provided on the other, and ball grooves formed on the outer and inner peripheral surfaces of the inner and outer joint members, respectively. A plurality of torque transmitting balls arranged between these ball grooves,
A cage formed between the inner and outer joint members and having a ball holding window for holding the torque transmitting ball, a predetermined position in the axial direction of the inner circumferential surface of the cage being a center,
In a constant velocity joint in which partial spherical regions are respectively formed on both sides in the axial direction from the center and the inner joint member is movable between the two partial spherical regions, partial spherical regions located on both sides in the axial direction from the center At least one of the partial spherical regions is formed by connecting a plurality of partial spherical surfaces having different radii of curvature or centers of curvature, and the plurality of partial spherical surfaces of the partial spherical region is moved in the axial direction of the inner joint member. A constant velocity joint characterized in that it is sometimes arranged so as to be able to simultaneously contact the inner joint member. 2. The constant velocity joint according to claim 1, wherein each partial spherical surface region includes two partial spherical surfaces. 3. The constant velocity joint according to claim 1, wherein the partial spheres constituting each of the partial spherical regions have different radii of curvature. 4. The constant velocity joint according to claim 1, wherein the partial spherical surfaces constituting each partial spherical region have different centers of curvature. 5. The constant velocity joint according to claim 1, wherein a center of a predetermined position in the axial direction of the inner circumferential surface of the cage is formed in a cylindrical surface. 6. The partial spherical surface region according to claim 1, wherein the two partial spherical regions are directly connected at a center of a predetermined position in the axial direction of the inner peripheral surface of the cage. Constant velocity joint.