JPH10238552A - Tripod type constant velocity universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the generation of induced thrust when torque is transmitted in a state that a joint is brought into an operation angle. SOLUTION: The outer peripheral surface (m) of the leg stem 5 of a tripod member 4 forms a spherical peripheral surface having a center P of the axis of the leg stem 5, and the cylinder inner peripheral surface (n) of a roller (7) is fitted in externally of a spherical outer peripheral surface (m) through a roller bearing 6. When, in a state that a joint is brought into a working angle θ, torque is transmitted, the roller 7 is tolled over a roller guide surface 3 with an attitude paralleling the axis of an outer ring 1 maintained in a way that smooth relative movement to the cylinder inner peripheral surface (n) of the roller 7 is effected as the spherical outer peripheral surface (m) of the leg stem 5 is rotated centering around the center P thereof, and smooth relative movement in the direction of the axis of an outer ring. This constitution reduces the generation of induced thrust.

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 universal joint applied to a front wheel drive type automobile or the like.

[0002]

2. Description of the Related Art FIG. 8A shows a constant velocity universal joint for transmitting rotational power of a drive shaft of a front-wheel drive automobile to front wheels at a constant speed.
And a tripod type as shown in FIG. In this case, three cylindrical track grooves 2 are formed on the inner peripheral surface of the outer ring 1 in the axial direction of the outer ring, and three leg shafts 11 protruding in the radial direction of the tripod member 4 inserted into the outer ring 1 are formed in a cylindrical shape. The roller 13 is rotatably inserted through the rolling element 12 on the outer peripheral surface of the roller. Each roller 1
Numerals 3 are accommodated in the track grooves 2 in a state of being engaged with roller guide surfaces 3 opposed to each other in the outer ring circumferential direction of the corresponding track grooves 2, and are movable in the outer ring axial direction while rotating about the leg shaft 11. .

As shown in FIG. 9, when the outer ring 1 and the tripod member 4 transmit a rotational force in a state where the operating angle θ is set, each roller 13 and the roller guide surface 3 of the track groove 2 are connected to each other as shown in FIG.
As shown in FIG. In this case, the roller 13 rolls in the direction indicated by the arrow a in FIG. 9, while the track groove 2 has a cylindrical shape parallel to the axial direction of the outer ring. Will do. As a result, a slip is generated between the roller guide surface 3 of the track groove 2 and the roller 13 to generate heat, and the slip generates an induced thrust in the axial direction. Since such induced thrust causes vibration and noise of the vehicle body, it is desired to reduce the induced thrust as much as possible.

[0004] As a tripod-type constant velocity universal joint in which the induced thrust is reduced, a roller having a two-story structure by combining an inner ring and an outer ring is known (Japanese Patent Publication No. 3-1529). In this joint, for example, as shown in FIG. 11, the inner ring 14 is rotatably fitted to the cylindrical outer peripheral surface of the leg shaft 11 of the tripod member 4 via the rolling element 16, and the outer ring 15 is mounted on the outer periphery of the inner ring 14. The two-story structure is constituted by rotatably fitting. The inner ring 14
Having a true spherical outer peripheral surface 17 centered on the axis of the leg shaft 11,
The cylindrical inner peripheral surface 18 of the outer ring 15 is rotatably fitted to the true spherical outer peripheral surface 17. The outer ring 15 is accommodated in the track groove 2 of the outer ring 1 and is movable in the axial direction of the outer ring while rolling on the roller guide surface 3.

[0005] As shown in FIG. 12, when the outer ring 1 and the tripod member 4 transmit the rotational force in a state where the operating angle θ is obtained,
The inner ring 14 is inclined with respect to the outer ring 15, and at this time, the inner ring 14 relatively moves on the cylindrical inner peripheral surface 18 of the outer ring 15 downward in FIG. 12. The inner and outer rings 14, 1
5, the outer ring 15 is guided by the roller guide surface 3 of the outer ring 1 in parallel with the axis of the outer ring 1, and the outer ring 15 rolls correctly on the roller guide surface 3, and Slip resistance is reduced, and generation of induced thrust is suppressed.

As another tripod type constant velocity universal joint in which the induced thrust is reduced, there is known a tripod type constant velocity universal joint in which a roller is supported on the outer peripheral surface of a leg shaft of a tripod member so as to be swingable. JP 54-13046 A). This joint is characterized in that, as shown in FIGS. 13 and 14, for example, the outer peripheral surface 22 of the leg shaft 21 of the tripod member 4 is formed into a spherical surface having a gentle curvature. In this case, the leg shaft 21
The cylindrical inner peripheral surface of one roller 24 is fitted through a rolling element 23 to the spherical outer peripheral surface 22 having a moderate curvature so as to be swingable. The outer peripheral surface of the roller 24 is rotatably fitted in the track groove 2 of the outer race 1 and slidably inserted in the axial direction of the outer race.

[0007] In the joint of FIG. 13 as well, when the outer ring 1 and the tripod member 4 transmit the rotational force in a state of taking the operating angle θ as shown in FIG. The inner circumferential surface of the cylinder slides, and the roller 24 swings to some extent with respect to the leg shaft 21. With this swing, the roller 24 is moved by the roller guide surfaces 3 on both sides of the track groove 2 of the outer ring 1. Are guided more or less parallel to the axis. Therefore, the roller 24 rolls on the roller guide surface 3 in the axial direction of the outer ring, so that the sliding resistance of the roller 24 is reduced, and the induced thrust is reduced.

[0008]

It has been found that in the joint of the two-stage roller structure shown in FIG. 11, the effect of reducing the induced thrust during the operation angle operation is stably exhibited. However, since the roller is composed of a combination of the inner ring and the outer ring, there is a problem that the number of parts and the number of assembly steps of the roller part increase, and the product cost increases.

Further, the joint shown in FIG. 13 has an advantage that the product cost is reduced because the roller has a simple (one-story) structure similar to that of FIG. However, in the case of this joint, FIG.
As shown in FIG. 4, even if the outer race 1 and the tripod member 4 have an operation angle θ, the spherical outer peripheral surface 22 of the leg shaft 21 and the rolling elements 2
3, it was necessary to set a desired radial gap g (not shown in the drawing).

That is, as shown in FIG. 15A, the radius of curvature (approximate value) at the center of the gentle spherical outer peripheral surface 22 of the leg shaft 21 is R, and the outer diameter is 2r. When the leg shaft 21 is inclined at the operating angle θ as shown in FIG. 15B, the points C and C ′ of the spherical outer peripheral surface 22 indicated by chain lines b and c in FIG. I do. These two places C, C '
Is located at a position where the radius [R− (R−r) cos θ] is increased, and in order to smoothly swing the leg shaft 21 with respect to the roller 24, a radial as a swing angle absorption amount between the two is required. It is necessary to set the direction gap g to a predetermined value such that g = 2 {[R− (R−r) cos θ] −r} = 2 (R−r) (1−cos θ).

Here, since the radial gap g is proportional to the amount of play in the circumferential direction of the universal joint, it is desirable to reduce the gap as much as possible. Therefore, in the joint shown in FIG. 13, the roller 2 is required at all the required operating angles θ unless an increase in backlash during the operating angle operation is permitted.
4 cannot maintain a posture parallel to the track groove 2.

A main object of the present invention is to provide a high-performance tripod-type constant velocity universal joint which reliably reduces the amount of backlash and induced thrust when operating at an operating angle.

[0013]

SUMMARY OF THE INVENTION According to the present invention, three track grooves formed on the inner periphery of an outer race in the axial direction of the outer race are rotatable about three leg shafts of a tripod member inserted into the outer race. A tripod-type constant velocity universal joint that accommodates the inserted roller, engages with the roller guide surface in the outer ring axial direction on both sides of the track groove, and can move in the outer ring axial direction while rolling on the roller guide surface. Therefore, in order to achieve the above object, the outer peripheral surface of the leg shaft of the tripod member is formed into a true spherical surface having a center on the axis of the leg shaft. The inner peripheral surface of the cylinder is externally fitted (claim 1).

Here, the roller which is fitted onto the outer peripheral surface of the true sphere of the leg shaft has a single so-called one-story structure. The outer peripheral surface of the true sphere is inserted. In this case, since the outer peripheral surface of the leg shaft is a perfect spherical surface, it is not necessary to set a radial gap between the leg and the rolling element as described in the related art. That is, the leg shaft can be tilted or swung with respect to the roller, and the dimensional relationship between the outer peripheral surface of the leg shaft and the rolling element is always constant regardless of the degree of the tilt angle.

On the other hand, when torque is transmitted with the joint at an operating angle, the roller rolls on the roller guide surface and moves in the track groove of the outer ring in the axial direction of the outer ring. At this time, keeping the posture of the roller parallel to the axis of the outer ring is effective in realizing the rolling of the roller with less resistance and thus the reduction of the induced thrust. The generatrix of the outer peripheral surface of the roller is preferably an arc having a center of curvature at a point radially away from the axial center of the roller on the outer peripheral surface side or on the opposite outer peripheral surface side. In this case, each roller guide surface may be a cylindrical surface whose axis passes through the center of curvature of the generatrix of the roller outer peripheral surface. Alternatively, the contact structure between the outer peripheral surface of the roller and the roller guide surface is made an angular contact by forming each roller guide surface into a shape in which the generatrix contacts the outer peripheral surface of the roller at two points separated in the axial direction of the roller. (Claim 2).

Further, a shoulder extending in the axial direction of the outer ring may be formed along the roller guide surface, and the shoulder may be engaged with the end face of the roller. This more reliably regulates the roller to a position parallel to the axis of the outer ring,
The rolling direction of the roller can be guided in the axial direction of the outer race.

With respect to the strength of the tripod type constant velocity universal joint, it is known that the strength of the roller and the strength of the rolling element have a dominant meaning. Second moment / PCD ⁴ ) is 0.028
1 × and 10 less than ^-3 exceeds 1.39 × 10 ^-3, and
(Rolling element diameter / PCD) exceeds 0.0417 and 0.37
When the number is less than 8, the strength required when used in a drive system of an automobile can be sufficiently satisfied.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 8 to 15.
The same reference numerals are given to the same or corresponding parts throughout all the drawings including, to avoid redundant description.

[0019] As shown in FIGS. 1A and 1B,
C type constant velocity universal joint is connected to one of the two shafts to be connected.
It has a ring 1 and a tripod member 4 coupled to the other. Outside
The ring 1 has a generally cup-shaped appearance, and three axially extending rings
Are formed on the inner peripheral surface at equal intervals in the circumferential direction.
You. The tripod member 4 has three leg shafts protruding in the radial direction.
5 are arranged at equal intervals in the circumferential direction, and each leg shaft 5 is
And carries a roller 7 which is rotatably fitted to the outside. roller
7 is accommodated in the track groove 2 of the outer race 1. Outer circumference of leg shaft 5
The surface m is a true spherical surface having a center P on the axis of the leg shaft 5.
A cylindrical roller 7 on the outer peripheral surface m of the sphere via a plurality of rolling elements 6
The inner peripheral surface n is fitted outside. Rolling element 6 rolls as shown
The moving surface is a cylindrical surface, the diameter is relatively large, and the length is longer than the diameter
The diameter is relatively small,
Needle roller (needle roller) that is longer than the diameter
Contrast with. At both ends of the opening of the inner circumferential surface n of the roller 7
The attached washer 8 prevents the rolling element 6 from coming off.

As can be seen from FIGS. 1B and 2,
Generatrix of the outer peripheral surface of the roller 7 is a circular arc having a center from the roller center P _R to the point p away radially outwardly. The track groove 2 for accommodating the roller 7 extends in parallel with the axis of the outer ring 1, and a pair of side walls facing the outer ring 1 in a circumferential direction becomes a roller guide surface 3 that contacts the outer peripheral surface of the roller 7. Each roller guide surface in FIG. 1B and FIG 2 3 is a cylindrical plane passing through the point p its axis spaced radially outwardly from the center P _R of the roller 7. In this way, by forming the generatrix of the outer peripheral surface of the roller 7 into an arc centered at a point radially away from the center of the roller on the outer peripheral surface side or on the opposite outer peripheral surface side, the joint is viewed in a longitudinal section (FIG. 1A) of the joint. As a result, the roller 7 is hardly inclined with respect to the roller guide surface 3. Therefore, the attitude of the roller 7 is kept parallel to the direction in which the roller guide surface 3 extends, that is, the axial direction of the outer race 1, so that the roller 7 can correctly roll on the roller guide surface 3. This is true even when the joint has an operating angle.

[0021] That is, as shown in FIG.
When the two axes make an angle, the joint takes the operating angle θ and the outer ring
1, the tripod member 4 is inclined by the angle θ. That
At this time, the outer circumference m of the true sphere of the leg shaft 5 is low (via the rolling elements 6).
The roller 7 relatively rotates within the cylindrical inner peripheral surface n of the roller 7, and the roller 7
While maintaining the attitude parallel to the axis of the outer ring in the rack groove 2,
Rolls along the guide surface 3, but at this time
And the induced thrust is suppressed. This operation
Mechanism for reducing induced thrust when operating at an angle
Nism is basically a roller structure shown in Figs. 11 and 122.
The same as the case of the joint of the structure, but will be described with reference to FIG.
And it is as follows.

As shown by a two-dot chain line in FIG. 4, when the center of the tripod member 4 when the operating angle is not taken is A, the center A is located on the axis X of the outer ring 1 and the roller 7 and the leg shaft 5
Is located on the axis B of the roller guide surface 3. As shown by the solid line in FIG. 4, when the joint takes the operating angle θ, the center A of the tripod member 4 moves to the point A ′ and shifts from the axis X downward in FIG. As a result, the axis of the leg shaft 5 is tilted by the angle θ, and the center P of the outer peripheral surface m of the true sphere moves relatively to the position P ′ below the axis B of the roller guide surface 3 in FIG. With this relative movement and the inclination of the leg shaft 5, the outer peripheral surface m of the leg shaft 5 moves while rotating the cylindrical inner peripheral surface n of the roller 7 about the center P thereof. 6 (omitted in FIG. 4; see FIG. 3). With the movement of the leg shaft 5,
The roller 7 rolls along the roller guide surface 3 and moves in the direction of the axis X of the outer ring parallel to the axis B of the roller guide surface 3 as indicated by the rightward arrow in the drawing. In this way, the relative movement between the leg shaft 5 and the roller 7 and the relative movement between the roller 7 and the roller guide surface 3 are both achieved with extremely small sliding friction, thereby suppressing the generation of induced thrust. Is done.

[0023] The roller 7 keeps the attitude parallel to the axis of the outer ring 1.
Roll on the roller guide surface 3 with less resistance
In order to ensure the reliability of the outer ring 1 above the roller guide surface 3
Shoulder extending in the axial direction of the outer race 1 along the roller guide surface 3
It is advantageous to form part 3a. Roller 7 on its end face
And always contact the shoulder 3a, so that it is parallel to the axis of the outer race 1.
Shoulder is maintained when rolling on roller guide surface 3 without losing posture
It is guided in the axial direction of the outer ring 1 by 3a. Accordingly
The roller 7 when operating with the joint at an operating angle.
Regulation or stabilization is more effectively achieved
You.

[0024] The roller guide surface 3 has various shapes in addition to the cylindrical surface described above.
It can be shaped. In the modification shown in FIG.
The outer peripheral surface 1 of the roller 7 and the roller guide surface 3 are separated in the axial direction.
A so-called angular contact that makes contact at two points Q and Q '
The structure is adopted. Also in this case, the attitude of the roller 7 is low.
Parallel to the direction in which the guide surface 3 extends, that is, the axial direction of the outer ring.
Will be kept. Two points, roller guide surface 3 and roller outer peripheral surface
The gap between Q and Q 'is effectively used as a grease pool.
You. Roller guide for achieving angular contact
Gothic arch, ellipse, parabola
Lines, hyperbolas and the like can be mentioned. Generating line of outer peripheral surface of roller 7
The shape is an arc having a center of curvature on the axis of the roller 7, a roller
Circle with center of curvature at a point radially away from axis 7
Set of arcs, arcs centered at points axially separated by roller 7
It is also possible to combine them.

In the modification shown in FIG. 6, a pair of roller guide surfaces 3 constituting the side walls of each track groove 2 are made parallel to each other, and shoulder portions 3a and 3b are formed on both upper and lower sides of each roller guide surface 3. The peripheral edge of the roller 7 is inserted between the shoulders 3a and 3b, and the cylindrical outer peripheral surface of the roller 7 is engaged with the flat roller guide surface 3. In this case, both end surfaces of the roller 7 are engaged with the shoulder portions 3a and 3b, and the posture of the roller 7 is stably regulated parallel to the axis of the outer ring 1.

As in the modification shown in FIG. 7, an annular flange 9 may be integrally formed at both ends of the cylindrical inner peripheral surface of the roller 7, and the rolling element 6 may be supported by the flange 9. Accordingly, the washer 8 for preventing the rolling element from being removed can be omitted, and the number of parts in the roller portion can be reduced.

By the way, in order to use a constant velocity universal joint in a drive system of an automobile, it is necessary to have strength capable of withstanding a drive torque. Generally, the reference strength of a constant velocity universal joint is determined by the strength of a shaft coupled to the constant velocity universal joint. Therefore, as described above, the leg shaft 5 is formed into a true spherical outer peripheral surface m.
A strength test was carried out on a tripod type constant velocity universal joint of the type provided with (see FIG. 16) from the viewpoint of determining a dimension parameter satisfying the strength condition. As a result of the test, it was found that there were two problems, the strength of the roller 7 and the strength of the rolling element 6. The evaluation is a value obtained by dividing the obtained test result (the strength of the constant velocity universal joint) by the static torsional strength of the shaft.
Based on (Equation 1), the clear condition was c> 0.93.

C = joint strength / shaft static torsional strength Formula 1 The strength of the roller 7 is greatly affected by the second moment of area of the roller 7, and the strength of the rolling element 6 is affected by the diameter of the rolling element. receive. In order to eliminate the influence of the size (model number of the joint), each dimension was divided by PCD to make it dimensionless, and the conditional expressions represented by Expressions 2 and 3 were obtained.

A = (Second moment of area of roller / PCD ⁴ ) Equation 2 b = Rolling element diameter / PCD Equation 3 FIG. 17 shows a plurality of test joints having different values of a and b. In the plot of the test data, the horizontal axis represents a and the vertical axis represents b. Each test data is composed of a symbol representing the evaluation and the values of a, b, and c.
Is “strength OK”, that is, the one that satisfies the condition of c> 0.93, ◇ is “roller NG”, that is, a roller has a defect, ◆ is “roller NG”, that is, a roller has a defect, ● indicates “roller / roller NG”, that is, the roller and the rolling element both failed, and × indicates “untested N
G "means that the lack of strength is apparent without conducting a test.

As can be seen from FIG. 17, the range of the value of the conditional expression a (Expression 2) relating to the roller 7 is represented by a symbol A, and the lower limit thereof is 0.0281 × 10 ⁻³ . The upper limit is calculated when the outer diameter of the outer ring is fixed, the outer diameter of the roller is maximized, the diameter of the trunnion journal and the diameter of the rolling element are minimized, and the thickness of the roller is maximized. Than,
It was 1.39 × 10 ⁻³ . From this, the range of a is
0.0281 × 10 ⁻³ <a <1.39 × 10 ⁻³ On the other hand, the range of the value of the conditional expression b (Equation 3) relating to the rolling element is represented by a symbol B, and the lower limit thereof is 0.0417. And the upper limit is to fix the outer ring outer diameter, maximize the roller outer diameter, minimize the leg shaft diameter and roller thickness,
When the rolling element diameter was maximized, it was 0.378 by calculation. Thus, the range of b is 0.0417 <b <
It was 0.378. Therefore, by setting a and b within the above ranges, the rollers and the rolling elements as the constant velocity universal joint for the drive system of the vehicle, and eventually the joint as a whole, have sufficient strength.

In order to improve the lubricity of the contact portion and prevent the trunnion journal portion from abrasion and peeling, an infinite number of minute concave recesses formed independently on the surface of the rolling element 6 are formed at random. . As a surface processing for obtaining the above rough surface conditions, a desired finished surface can be obtained by special barrel polishing. The surface roughness of the rough surface 6a of the rolling element is Rmax 0.6 to 2.5.
The parameter Sk value of μm and surface roughness is -1.6 or less. The average area of the fine dents of the fine rough surface 6a is 35 to 180 μm ² , and the ratio of the dents to the entire surface is 10 to 40%. The parameter SK value refers to the degree of distortion (SKEWNESS) of the surface roughness distribution curve, and a symmetric distribution such as a Gaussian distribution has an SK value of 0. However, the parameter SK value is determined in both the circumferential direction and the axial direction. -1.6
The following set values are in a range where the shape and distribution of the surface concave portions are advantageous for the oil film shape depending on the processing conditions.

For a tripod type constant velocity universal joint in which the outer peripheral surface of a leg shaft is a truly spherical surface, the one using a rolling element subjected to the above-mentioned surface processing and the one using a conventional rolling element having a super-finished surface are used. FIG. 18 shows the results of the durability test performed on each of them. The test conditions A and B in the figure are as shown in Table 1.

[0033]

[Table 1]

As is clear from the test results shown in FIG. 18, in the case of the test condition B, the defect of the conventional device became large at the time of operation for 96 hours, whereas the device of the present invention was replaced by the conventional device. In comparison, no malfunction occurred even when the operation time exceeded 160% or more. Even in the case of the test condition A, the one of the present invention has a life of 200% or more as compared with the conventional one. In this way, by performing the above-mentioned surface processing on the rolling element, the lubricating property is improved, which is advantageous for forming an oil film on the rolling element surface, the rotation property of the roller is improved, and between the rolling element and the roller, between the rolling element and the rolling element. The slipperiness between the trunnion journals can be improved, and the occurrence of wear and peeling of each contact portion can be minimized.

[0035] In addition, for example, regarding FIGS.
In other words, when the joint is not at an operating angle,
So that both the center and the center of the roller 7 are at the same point P
As shown, these centers are off in the axial direction of the leg shaft 5.
May be set. When the joint takes the working angle,
As described above, the center of the leg shaft 5 is the axis of the outer race 1.
It moves toward the center X, that is, from point P to point P '. Soy sauce
When transmitting torque with the joint at an operating angle
Means that the center of the leg shaft 5 and the center of the roller 7 are not in the axial direction of the leg shaft.
It is. Therefore, as shown in FIG.
A predetermined amount from the center P of the leg shaft 5 toward the axis X of the outer ring 1
The joint at an operating angle.
When transmitting torque, the center P of the leg shaft 5 is aligned with the axis X of the outer race 1.
Move to the side to match or approach the center of roller 7
It will be. This type of joint is used at an operating angle
This is because the operation is rather normal.
Considering the behavior when transmitting torque in an angled state
The significance of the configuration included will be clear.

[0036]

According to the tripod type constant velocity universal joint according to the first aspect, when the joint has an operating angle, the tripod member legs with respect to the cylindrical inner peripheral surface of the roller inserted into the track groove of the outer ring. The outer peripheral surface of the true sphere rotates relative to the center of curvature and moves the roller relatively in the axial direction of the track groove, so the generation of induced thrust is suppressed to the same extent as a conventional two-story roller structure joint. Thus, a high-quality, high-performance tripod-type constant velocity universal joint with less heat, vibration, and noise can be provided. In addition, the reduction of induced thrust when the joint is operated at an operating angle is realized by a simple single-stroke roller structure tripod member, which reduces the cost of a high quality and high performance tripod type constant velocity universal joint. Is achieved.

According to the second and third aspects of the present invention,
The roller guide surface of the track groove of the outer ring, the angular contact on the outer peripheral surface of the roller, and the shoulder of the roller guide surface regulate the movement of the roller in the axial direction of the outer ring during operation of the joint at a stable angle. Thus, generation of stable induced thrust can be suppressed.

According to the fourth aspect of the present invention, it is possible to accurately determine the dimensions required to satisfy the required strength, and to sufficiently satisfy the strength required for use in a drive system of an automobile. It is possible to provide a tripod type constant velocity universal joint.

[Brief description of the drawings]

1 (A) is a front view including a partial cross section of a tripod type constant velocity universal joint, and FIG. 1 (B) is a cross-sectional view of a main part of the joint of FIG. 1 (A).

FIG. 2 is a partially enlarged cross-sectional view of a roller and a roller guide surface in FIG.

3 is a schematic cross-sectional view of a main part of the joint shown in FIG. 1 in an operation angle.

FIG. 4 is a diagram illustrating a relative relationship between a roller and a leg shaft for explaining relative movement of the roller of the joint of FIG. 3;

FIG. 5 is a partially enlarged sectional view similar to FIG. 2 showing another embodiment.

FIG. 6 is a cross-sectional view similar to FIG. 1B showing another embodiment.

FIG. 7 is a cross-sectional view similar to FIG. 1B showing another embodiment.

8 (A) is a longitudinal sectional view of a conventional tripod type constant velocity universal joint, and FIG. 8 (B) is a transverse sectional view of the joint of FIG. 8 (A).

FIG. 9 is a partially cutaway front view of the joint of FIG. 8 at an operating angle.

FIG. 10 is a perspective view showing a rolling state of a roller in the joint of FIG. 9;

FIG. 11 is a longitudinal sectional view of another conventional tripod type constant velocity universal joint.

FIG. 12 is a longitudinal sectional view of the joint of FIG. 11 in a state where the operating angle is set;

FIG. 13 is a schematic view of a main part of another conventional tripod type constant velocity universal joint.

FIG. 14 is a schematic view of a main part of the joint of FIG. 13 in a state where an operation angle is set.

15A is a schematic front view of a leg shaft in the joint of FIG. 13, and FIG. 15B is a schematic front view of a leg shaft in the joint of FIG.

FIG. 16 is a cross-sectional view of a main part for describing dimensions.

FIG. 17 is a graph plotting strength test results.

FIG. 18 is a graph showing a durability test result.

FIG. Shows a modified example in which the center of the leg axis and the center of the roller are shifted.
FIG. 17 is a sectional view similar to FIG.

[Explanation of symbols]

 Reference Signs List 1 outer ring 2 track groove 3 roller guide surface 3a shoulder 4 tripod member 5 leg shaft 6 roller bearing 7 roller

Claims (4)

[Claims] 1. An outer ring formed on an inner periphery of an outer ring in an axial direction of the outer ring.
Rollers rotatably fitted to the three leg shafts of the tripod member inserted into the outer race are engaged with the roller guide surfaces in the outer race axial direction on both sides of the track groove to rotate and rotate. In a tripod-type constant velocity universal joint slidably inserted, the outer peripheral surface of the leg shaft is formed as a true spherical surface having a center on the axis of the leg shaft. A tripod-type constant velocity universal joint, wherein a cylindrical inner peripheral surface of a roller is externally fitted. 2. The tripod type constant velocity universal joint according to claim 1, wherein the roller guide surface of the track groove of the outer race and the outer peripheral surface of the roller make angular contact. 3. A roller guide surface of a track groove of the outer ring, wherein a shoulder portion is formed parallel to the track groove and engaged with an end face of the roller to regulate a rolling direction of the roller parallel to the track groove direction. The tripod type constant velocity universal joint according to claim 1, wherein 4. The second moment of area of the roller / PCD ⁴
Is more than 0.0281 × 10 ⁻³ and less than 1.39 × 10 ⁻³ , and rolling element diameter / PCD is more than 0.0417 and less than 0.378. 2 or 3 tripod type constant velocity universal joint.