JP4903533B2 - Assembling method of tripod type constant velocity universal joint - Google Patents

Description

  The present invention relates to a tripod type constant velocity universal joint used in a power transmission device of an automobile or various industrial machines.

  For example, in a drive shaft that transmits torque from an automobile engine to a wheel, one end of the drive shaft is connected to a differential via a sliding type constant velocity universal joint, and the other end is connected to a wheel via a fixed type constant velocity universal joint. The As a sliding type constant velocity universal joint used for a drive shaft, for example, a tripod type constant velocity universal joint is known.

As shown in FIG. 5, the tripod type constant velocity universal joint accommodates a tripod member 20 as an inner joint member having three trunnion journals 26 projecting radially on the inner periphery of the outer ring 10 as an outer joint member. This is the structure. A roller 30 as a torque transmission member is rotatably attached to each trunnion journal 26 via needle rollers 32 . The roller 30 is accommodated in a track groove 14 formed on the inner periphery of the outer ring 10, and can roll in the axial direction of the outer ring 10 along the side wall surface (roller guide surface) of the track groove 14. This allows axial displacement (plunging) between the two axes of the drive side and the driven side. In FIG. 5, reference numeral 28 denotes an annular groove formed in the trunnion journal 26, and reference numeral 38 denotes a circlip attached to the annular groove 28. Reference numerals 34 and 36 denote an inner washer and an outer washer arranged on both sides of the needle roller 32.

  By the way, for example, in the process of assembling the drive shaft to the vehicle body, the drive shaft may have to be tilted or made vertical. When the tripod type constant velocity universal joint is turned up, the tripod member 20 may fall off the outer ring 10 due to the weight. Therefore, conventionally, a clip (not shown) is attached to the inner periphery of the opening of the outer ring 10 as a measure for preventing the tripod member 20 from coming off. That is, a circular engagement groove is formed on the inner peripheral surface of the outer ring 10, a circlip is attached thereto, and this circlip is caused to interfere with the roller 30, thereby preventing the tripod member 20 from coming off.

Patent Document 1 proposes that the open end of the outer ring is provided with a crimp that forms a raised portion whose end face reduces the area in the cup, and the raised portion is used to prevent it from coming off. . Patent Document 2 proposes that the roller guide surface of the outer ring is cured by heat treatment leaving the vicinity of the opening, and an uncured portion near the opening is formed with a protruding portion capable of interfering with the roller by plastic deformation. ing.
Japanese Patent Application Laid-Open No. 11-336782 JP 2002-235766 A

  As a countermeasure for preventing the internal parts of the sliding type constant velocity universal joint (for example, tripod kit (20, 30, 32) in the case of a tripod type constant velocity universal joint) from dropping from the outer ring 10, Patent Document 1 and Patent The retainer described in Document 2 has a cost advantage because the number of parts does not increase as compared with a method of attaching a retainer clip, but has a problem. That is, since the raised part is an open end, the thing of patent document 1 is close to the boot which is easy to tear, and it is necessary to process so that it may not interfere with a boot, and processing is difficult. In Patent Document 2, since the roller guide surface is a surface, it is difficult to form the protruding portion by plastic deformation.

  The object of the present invention is to prevent the tripod kit from falling off the outer ring while eliminating the above-mentioned problems.

The present invention solves the problem by making the track clearance (the clearance between the track groove and the roller) a negative clearance near the open end of the outer ring. That is, the present invention is an assembling method of a tripod type constant velocity universal joint, and the tripod type constant velocity universal joint has a cross-sectional shape in which a large diameter portion and a small diameter portion appear alternately in the circumferential direction, has an inner periphery extending axially total of three track grooves of diameter, tripod having an outer ring forming the roller guide surface on opposite side walls of each track grooves, the three trunnion journals radially projecting member and, a roller housed in the track groove of the rotatably supported on the trunnion journal outer ring, Ri set tare as track clearance becomes negative clearance in outer open end, three trunnion journals When inserting the three rollers carried on the outer ring into the track grooves of the outer ring, by applying force from the three outer diameter directions to the outer ring open end of the large diameter part, elastic deformation Is characterized in passing the roller is spread more tracks gap. Here, the track clearance means a clearance between the track groove and the roller. The tripod kit includes a tripod member and a roller supported by a trunnion journal of the tripod member via needle rollers, and moves as a unit with respect to the outer ring.

  According to this invention, it is possible to prevent the tripod kit from falling off the outer ring. And compared with the thing of patent document 1, since it does not give a process to an open end, there is no fear that a boot will be torn, and since a special process is not needed, a process is easy. Further, as compared with that of Patent Document 2, no special processing such as molding of the protruding portion is required, so that processing is easy.

  Embodiments of the present invention will be described below with reference to the drawings.

  The basic structure will be described with reference to FIG. 5. The tripod type constant velocity universal joint mainly includes an outer ring 10 as an outer joint member, a tripod member 20 as an inner joint member, and a roller 30 as a torque transmission element. As an element. One of the two shafts to be coupled is coupled to the outer ring 10 and the other is coupled to the tripod member 20.

The outer ring 10 includes a mouse portion 12 and a stem portion 16, and is coupled to one of the two shafts to be connected by a spline (or serration, the same applies hereinafter) shaft 18 of the stem portion 16 so that torque can be transmitted. ing. The mouse portion 12 is cup-shaped, and three track grooves 14 extending in the axial direction on the inner periphery are formed at equal intervals in the circumferential direction. Side walls facing each other in the circumferential direction of each track groove 14 serve as a roller guide surface .

  The tripod member 20 includes a boss 22 and three trunnion journals 26, and the trunnion journal 26 projects radially from the circumferentially equidistant position of the boss 22. The boss 22 is coupled to the other of the two shafts to be connected by a spline hole 24 formed in the center so as to transmit torque.

The roller 30 is rotatably supported on the trunnion journal 26 via needle rollers 32. The roller 30 is accommodated in the track groove 14 of the outer ring 10, and the outer peripheral surface of the roller 30 is a convex curved surface that fits the roller guide surface.

  In order to prevent the tripod kit (20, 30, 32) from falling off the outer ring 10, the track clearance (the clearance between the track groove 14 and the roller 30) is a negative clearance near the open end of the outer ring 10. Specifically, the track clearance is set to be negative in the vicinity of the open end of the outer ring 10 indicated by the dotted line in FIG. 1, and the conventional positive clearance is set to other portions. 2 shows the positional relationship between the track groove 14 and the roller 30 as viewed from the line II-II in FIG. 1. The width dimension of the track groove 14 is b, and the width dimension of the track groove 14 near the open end of the outer ring 10 is shown. b ′, the outer diameter of the roller 30 is represented by φd. These dimensional relationships are set such that bd> 0 and b′−d <0.

  Next, a method of incorporating the tripod kit (20, 30, 32) into the outer ring 10 will be described with reference to FIGS. As shown in FIG. 3, when the tripod kit (20, 30, 32) is assembled into the outer ring 10, the roller 30 and the outer ring 10 are elastically deformed by applying force to the roller 30 in the direction of the arrow in the figure. By utilizing this, the roller 30 near the open end of the outer ring 10 and the negative clearance between the track grooves 14 are passed.

  Further, as shown in FIG. 4, when the tripod kit (20, 30, 32) is assembled into the outer ring 10, the outer ring 10 is viewed from three directions indicated by large inward arrows in the vicinity of the open end of the outer ring 10. A force is applied and the outer ring 10 is bent by elastic deformation. Then, the roller 30 in a state in which the track groove 14 of the outer ring 10 is bent and expanded in the direction of the outward small arrow (the roller near the open end of the outer ring and the negative clearance portion of the outer ring track is widened to be a positive clearance). Pass through. After the roller 30 has passed, if the force indicated by the large arrow is released, the outer ring 10 is restored and the tripod kit (20, 30, 32) does not fall off.

The longitudinal cross-sectional view of the tripod type constant velocity universal joint which shows embodiment of this invention II-II arrow view of FIG. 1 showing the positional relationship between the outer ring track groove and the roller Figure similar to Figure 2 showing the roller assembly process End view of outer ring Vertical section of tripod type constant velocity universal joint, (B) is an end view

Explanation of symbols

10 Outer ring (outer joint member)
12 Mouse part 14 Track groove 16 Stem part 18 Spline shaft 20 Tripod member (inner joint member)
22 Boss 24 Spline hole 26 Trunnion journal 28 Ring groove 30 Roller (torque transmission element)
32 Needle roller 34 Inner washer 36 Outer washer 38 Circlip

Claims (1)

It has a cross-sectional shape in which a large-diameter portion and a small-diameter portion appear alternately in the circumferential direction, and has a total of three track grooves extending in the axial direction on the inner periphery of the large-diameter portion. A track clearance comprising: an outer ring having a roller guide surface; a tripod member having three trunnion journals projecting radially; and a roller rotatably supported by each trunnion journal and housed in a track groove of the outer ring. Is a method for assembling a tripod type constant velocity universal joint that is set to have a negative clearance at the open end of the outer ring, in which three rollers carried by three trunnion journals are respectively inserted into the track grooves of the outer ring. In this case, by applying force from the three outer diameter directions to the open end of the outer ring of the large diameter portion, the track clearance is expanded by elastic deformation and the roller is allowed to pass. How to.

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