JP2003028186A - Tripod type constant velocity universal joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of part items and assembling man-hours of a washer for preventing a fall of rolling bodies installed in each leg shaft in a joint having rollers fitted to the leg shafts of a tripod member through several cylindrical rolling bodies freely to rotate. SOLUTION: This constant velocity universal joint has the structure formed by fitting the cylindrical inner peripheral surface of the roller to the outer peripheral surface of three leg shafts 5 of the tripod member 4 through a series of several cylindrical rolling bodies 6 to assemble the tripod member 4. The cylindrical inner peripheral surface of the roller 7 is formed with a flange part 8 to be locked with an end surface of the rolling body 6 to prevent a fall of the rolling body 6 in the axial direction. This flange part 8 is utilized to assemble a constant number of rolling bodies 6 in the inner peripheral surface of the roller 7 with a keystone method to form an assembly hard to be disassembled, and the roller 7 is assembled in the leg shaft 5 at the same time with the rolling body 6.

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 front wheel drive type automobiles and the like.

[0002]

2. Description of the Related Art A conventional example of a tripod type constant velocity universal joint for transmitting the rotational power of a drive shaft of a front wheel drive automobile to a front wheel at a constant speed is shown in FIGS. 8 (A) and 8 (B). The rollers 7 rotatably fitted to the three leg shafts 5 projecting in the radial direction of the tripod member 4 are fitted into the three cylindrical track grooves 2 formed in the outer ring axial direction of the inner peripheral surface of Consists of The outer peripheral surface of each leg shaft 5 is, for example, a cylindrical surface, and a plurality of cylindrical rolling elements (rollers, needle bearings, etc.) are formed on the outer peripheral surface.
The cylindrical inner peripheral surface of the roller 7 ′ is rotatably fitted and inserted via 6. The rollers 7 ′ correspond to the corresponding track grooves 2 of the outer ring 1.
In the state of being engaged with the roller guide surfaces 3 on both sides of the outer ring 1, the track groove 2 is rotatably fitted and slidably fitted in the outer ring axial direction, and the rotational force between the tripod member 4 and the outer ring 1 is increased. To communicate.

The outer peripheral surface of the leg shaft 5 of the tripod member 4 is, for example, a cylindrical surface as shown in FIG. 9, and the inner washer 11 is fitted to the base end portion of this cylindrical surface, and the outer washer 12 and the clip 13 are fitted to the distal end portion thereof. A plurality of rolling elements 6 having the same diameter are fitted between the washers 11 and 12 in series. The plurality of rolling elements 6 are arranged in series along the outer circumference of the leg shaft 5 without any gap. The outer washer 12 contacts the end face of the rolling element 6,
The axial position of the rolling element 6 on the leg shaft 5 is regulated to prevent slipping off in the axial direction. The clip 13 fits into the groove 14 formed on the outer periphery of the leg shaft 5 to fix the outer washer 12 to the leg shaft 5.

[0004]

In the tripod member 4 shown in FIG. 9, a plurality of rolling elements 6 are arranged in series on the outer periphery of the leg shaft 5 and the roller 7'is fitted and inserted, or the leg shaft 5 is assembled. Any of the assembling operations of inserting the rollers 7'and inserting the plurality of rolling elements 6 between them requires a lot of man-hours and is difficult.
This deteriorates the workability of assembling the tripod type constant velocity universal joint.

Further, the outer washer 12 for preventing the rolling element 6 attached to the leg shaft 5 from coming off needs to have a special shape that also prevents the roller 7'from coming off, and the outer washer 12 There is also a problem that the clip 13 for attaching the to the leg shaft 5 is also required, the number of parts of the tripod member 4 and the number of assembling steps increase, and it is difficult to reduce the manufacturing cost thereof.

An object of the present invention is to provide a low cost tripod type constant velocity universal joint which is easy to assemble.

[0007]

The technical means for achieving the above-mentioned object of the present invention is to provide three track grooves formed in the outer ring axial direction on the inner circumference of the outer ring and three leg shafts of the tripod member. In a tripod type constant velocity universal joint in which a roller rotatably supported via a plurality of cylindrical rolling elements is housed, and the roller is movable in the outer ring axial direction while rolling on the roller guide surface of the track groove, A flange portion is formed on the inner peripheral surface of the roller of the tripod member to prevent the continuous cylindrical rolling elements from slipping out in the axial direction, and one of the plurality of rolling elements is formed on the inner peripheral surface of the roller along the flange portion. , And the remaining one rolling element is pressed into the gap between the two rolling elements on both ends of this series of rolling elements with a tightening margin of several μ to several tens of μ, and a predetermined number of rolling elements are placed on the inner circumference of the roller. It is an assembly that does not come loose by incorporating it on the surface. A cylindrical roller can be applied to the rolling element of the present invention.

Here, the flange portion on the inner peripheral surface of the roller is formed in a protruding manner at both ends of the inner peripheral surface of the roller in the axial direction so as to project integrally, or on both ends of the inner peripheral surface of the roller in the axial direction in the circumferential direction. It is desirable that the washer is partially inserted into the groove so as to simplify the structure of the collar portion. By forming such a flange portion on the inner peripheral surface of the roller, a member for preventing the rolling element from slipping off on the leg shaft of the tripod member, a structure is not necessary, and the number of parts of the tripod member and the number of assembly steps can be reduced, Also,
The following method of assembling the tripod member is possible.

That is, a flange portion is formed on the inner peripheral surface of the roller of the tripod member to prevent the continuous cylindrical rolling elements from coming off in the axial direction, and a plurality of rolling members are formed on the inner peripheral surface of the roller along the flange portion. One of the moving elements is left in a line, and the remaining one rolling element is left in the gap between the two rolling elements of this series of rolling elements.
A manufacturing method is possible in which a predetermined number of rolling elements are press-fitted into the roller inner peripheral surface by press-fitting with a tightening margin of 0 μ to form an immovable assembly, and the rollers are assembled together with the rolling elements to the leg shaft in this assembled state.

A method of arranging rolling elements in series on the inner circumferential surface of the roller in the above manufacturing method is called a keystone method, and when the roller is assembled with the leg shaft together with the rolling element, the collar portion of the roller prevents the rolling element from falling off. . According to this manufacturing method, the roller and the rolling element can be integrated as an undisturbed assembly and simultaneously assembled to the leg shaft, so that the workability of assembling the tripod member, and thus the tripod type constant velocity universal joint, is excellent. To

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below with reference to FIGS. Note that the same portions or corresponding portions are denoted by the same reference numerals throughout the drawings including FIGS. 8 and 9 to avoid duplication of description.

The tripod member 4 shown in FIG. 1 has a roller 7 fitted around the leg shaft 5 through a plurality of rolling elements 6.
A flange portion 8 is formed on the inner peripheral surface of the to prevent the rolling element 6 from falling off. The outer ring of the tripod type constant velocity universal joint (not shown) may have the same structure as that shown in FIG. The outer peripheral surface of the leg shaft 5 is, for example, a cylindrical surface, and a plurality of cylindrical rolling elements 6 are arranged in series on the outer peripheral surface of the cylinder without a gap. The cylindrical inner circumferential surface of the roller 7 is arranged around each rolling element 6. The surface is inserted.

A collar portion 8 formed on the inner peripheral surface of the cylinder of the roller 7.
A specific example of is shown in FIGS. 2 (A) and 2 (B). Figure 2
The collar portion 8 of (A) is a pair of convex step portions 8 a integrally provided on both axial end portions of the cylindrical inner peripheral surface of the roller 7. For example, a groove into which the peripheral edge portion of the rolling element 6 is fitted is formed in the central portion of the inner peripheral surface of the roller 7 excluding both axial end portions, and convex step portions 8a are formed at both axial end portions of this groove. Collar part 8 of FIG. 2 (B)
Is formed by a pair of washers 8b fitted in grooves 10 formed at both axial ends of the inner peripheral surface of the roller 7.
The projecting length of this washer 8b from the inner peripheral surface of the roller cylinder is
This corresponds to the step difference of the convex step portion 8a in FIG.

The tripod member 4 can be assembled by the assembling method shown in FIG. 3 or FIG. 4 by forming the rolling member slip-out preventing collar portion 8 on the inner peripheral surface of the roller 7.

FIG. 3 shows the case where the roller 7 of FIG. 2 (A) is attached to the leg shaft 5, and all the rolling elements 6 are temporarily adhered to the inner peripheral surface of the cylinder of the roller 7 with grease 9 and arranged in series. In this state, the roller 7 is integrated with the rolling element 6 and fitted into the leg shaft 5. The grease 9 is an existing one that smoothens the rotation of the rolling elements 6. The grease 9 is applied in advance to the inner peripheral surface of the cylinder of the roller 7 in a desired thickness, and the rolling elements 6 are pressed onto the grease 9 to temporarily suspend the plurality of rolling elements 6. To glue. After that, when the roller 7 is inserted into the cylindrical outer peripheral surface of the leg shaft 5 together with the rolling element 6, the flange portion 8 of the roller 7 prevents the rolling element 6 from falling off and the roller 7 and the rolling element 6 are moved to the leg axis 5. The insertion is sure and smooth.

FIG. 4 also shows how the roller 7 of FIG. 2 (A) is attached to the leg shaft 5. In this case, a plurality of rolling elements 6 are temporarily provisioned on the inner peripheral surface of the cylinder of the roller 7 by the keystone method. In the stopped state, the roller 7 is assembled with the rolling element 6 on the leg shaft 5. For example, as shown in FIGS. 5A and 5B, a plurality of rolling elements 6 that is one less than the total number are arranged in series on the inner peripheral surface of the cylinder of the roller 7, and the two rolling elements 6 at both ends of the rolling element 6 are arranged.
The last rolling element 6 is press-fitted into the gap g formed between the rolling elements. In this case, the relationship between the diameter d1 of the rolling element 6 and the minimum gap d2 of the gap g is set to d1> d2, and the difference [d1-d
2] is a narrowing margin of several μ to several tens of μ. In this way, when the last one rolling element 6 is press-fitted into the gap g, all the rolling elements 6 are temporarily held in series on the inner peripheral surface of the cylinder of the roller 7.

Also in the case of FIG. 4, when the roller 7 is assembled with the rolling element 6 on the cylindrical outer peripheral surface of the leg shaft 5, the collar portion 8 of the roller 7 is mounted.
Thus, the rolling element 6 is prevented from falling off, and the roller 7 and the rolling element 6 are assembled to the leg shaft 5 at the same time, reliably and smoothly.
In addition, the plurality of rolling elements 6 previously attached to the roller 7 by the keystone method can smoothly rotate between the leg shaft 5 and the roller 7 without any problem if the tightening margin is in the above range.

As described above, the work of assembling the tripod member 4 by inserting the unit in which the rolling element 6 is assembled to the roller 7 into the leg shaft 5 is technically easier than the conventional assembling work, and the number of man-hours is increased. Assembling workability is further improved.
Further, when the flange portion 8 is integrally formed on the inner peripheral surface of the cylinder like the roller 7 of FIG. 2 (A), the washer and the clip attached to the leg shaft 5 for preventing the rolling element from coming off can be omitted. The number of parts of the tripod member 4 and the number of assembling steps are reduced, and the manufacturing cost is easily reduced.

Even in the case where the collar portion 8 is composed of the washer 8b like the roller 7 of FIG. 2B, the tripod member can be assembled by using the grease adhesion method of FIG. 3 or the keystone method of FIG. It is possible. This Figure 2 (B)
Since the pair of washers 8b are used to prevent the rolling elements from coming off in the roller 7, there is no effect of reducing the number of parts described above. Since such a simple shape and low cost can be used, it is possible to reduce the manufacturing cost of the tripod member.

In the above embodiment, the roller 7 is fitted and inserted into the cylindrical outer peripheral surface of the leg shaft 5 of the tripod member 4 via the cylindrical rolling element 6, but in the present invention, the outer peripheral surface of the leg shaft 5 is The present invention can be applied to a tripod member having a spherical surface, and the roller 7 is swingably mounted on the spherical surface. A specific example thereof will be described with reference to FIGS. 6 and 7.

The leg shaft 5 of the tripod member 4 shown in FIG.
The outer peripheral surface of is a true spherical surface having a radius R1 having a center P1 on the axis of the leg shaft 5, and the rolling element 6 slidably makes point contact with the true spherical surface to cause the roller 7 to swing about the leg shaft 5. It is installed as possible. Such a tripod member 4 is effectively applied to the constant velocity universal joint disclosed in Japanese Patent Application No. 8-19106, which is a prior application of the present applicant.

The leg shaft 5 of the tripod member 4 shown in FIG.
The outer peripheral surface of is a substantially elliptical spherical surface having a center P2 at a position deviated from the axis of the leg shaft 5 and having a radius R2.
Is in slidable point contact, and the roller 7 is attached to the leg shaft 5 so as to be swingable.

[0023]

According to the tripod type constant velocity universal joint of the present invention, the roller of the tripod member is provided with the flange portion for preventing the rolling element from slipping off, and all the rolling elements are assembled on the inner peripheral surface of the roller by the keystone method. Since it is an assembly that can not be assembled, by assembling this assembly to the leg shaft of the tripod member, the tripod member can be assembled, the man-hours for assembling the tripod member can be reduced, the assembling workability can be improved, and the mass productivity is excellent. ,
Therefore, a low-cost tripod type constant velocity universal joint can be manufactured.

[Brief description of drawings]

FIG. 1 is a front view including a partial cross section of a tripod member in a constant velocity universal joint according to an embodiment of the present invention.

2A is an enlarged sectional view of a roller and a rolling element in the tripod member of FIG. 1, and FIG. 2B is an enlarged sectional view of a roller and a rolling element of another structure in the tripod member of FIG. is there.

3 is a partial front view of the tripod member of FIG. 1 during assembly.

4 is a partial front view of the tripod member of FIG. 1 when assembled by another method. FIG.

5 (A) is an enlarged sectional view of the roller of FIG. 4 when the rolling elements are assembled, and FIG. 5 (B) is a partially enlarged plan view of FIG. 5 (A).

FIG. 6 is a front view including a partial cross section of a tripod member according to another embodiment of the present invention.

FIG. 7 is a front view including a partial cross section of a tripod member according to another embodiment of the present invention.

8A is a partial sectional view of a conventional tripod type constant velocity universal joint, and FIG. 8B is a partial vertical sectional view of the joint of FIG. 8A.

9 is an enlarged front view of the tripod member in the joint of FIG.

[Explanation of symbols]

1 outer ring 2 track grooves 3 Roller guide surface 4 Tripod members 5 legs 6 rolling elements, rollers 7 Laura 8 collar part 8a convex step 8b Washer (flange) 9 grease 10 washer groove

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tatsuhiro Goto             1031 Sennedo, Iwata-shi, Shizuoka Prefecture Maine Maison             No. 101

Claims (2)

[Claims] 1. An outer ring formed on the inner circumference of the outer ring in the axial direction of the outer ring.
A roller rotatably supported on the three leg shafts of the tripod member via a plurality of cylindrical rolling elements is housed in the track groove of the book, and the roller rolls on the roller guide surface of the track groove to move outside. In a tripod type constant velocity universal joint that is movable in the axial direction of the wheel, a collar portion that prevents axial removal of a plurality of continuous cylindrical rolling elements is formed on the inner peripheral surface of the roller of the tripod member,
Along the flange portion, one of the plurality of rolling elements is left in series on the inner peripheral surface of the roller, and one rolling element is left in the gap between the two rolling elements on both sides of the rolling element. A tripod type constant velocity universal joint, characterized in that a predetermined number of rolling elements are press-fitted with a tightening margin of several tens of µm and a predetermined number of rolling elements are incorporated into the inner peripheral surface of the roller to form an assembly that does not disperse. 2. The tripod type constant velocity universal joint according to claim 1, wherein the rolling element is a cylindrical roller.