JPS5923864Y2 - tripod joint - Google Patents

Description

[Detailed explanation of the invention] This invention uses a roller that is supported by three trunnions each extending in the radial direction of the tripod shaft, and that moves along the roller groove of the tulip shaft that pairs with each trunnion. This invention relates to a tripod joint used as a torque transmission member.

FIG. 1 is an explanatory diagram showing a general tripod joint.

Three trunnions 3 are radially extended on the outer circumference of the tripod 2 connected to the end of the first shaft 1, and each trunnion 3 is connected to a roller having a hemispherical surface via a double bearing 4. 5 is pivotally supported to allow rotation and axial movement of the trunnion 3.

The rollers 5 are removably fitted into roller grooves 7 that form inner spherical surfaces in the longitudinal direction facing each other in the three-position lid corresponding to the trunnion 3 of the tulip 6, and a second shaft is attached to the end of the tulip 6. 8 are connected.

Transmission torque between the first shaft 1 and the second shaft 8 in such a tripod joint is transmitted via the trunnion 3, needle bearing 4, roller 5, and tulip 6.

Further, when transmitting torque with a joint angle between the first shaft 1 and the second shaft 8, the roller 5 rotates and moves in the axial direction with respect to the trunnion 3. .

FIG. 2 is an explanatory diagram showing a conventional trunnion end structure in such a tripod joint.

A conical chamfer 5A is formed on the inner diameter portion of the outer end surface of the roller 5 which is pivotally supported by the trunnion 3 via a needle bearing 4, and a retainer 9 is provided at the end of the trunnion 3. An annular groove 1 formed at the end of
It is mounted in a state where it is positioned by contacting the tapered surface with the snap ring 11 which is locked at 0.

The retainer 9 has a conical shape and is in contact with the end face of the needle bearing 4 at the thrust receiving surface 9A formed on its inner surface to prevent the needle bearing 4 from coming off in the axial direction. It contacts the chamfered portion 5A to restrict the predetermined axial movement of the roller 5, thereby preventing the roller 5 from coming off the trunnion 3.

However, in a tripod joint made of such a conventional trunnion end structure, the roller 5 is prevented from coming off by the nottainer 9 arranged adjacent to the needle bearing 4, so that the permissible axial movement of the roller 5 is limited. The amount becomes small, and it is not possible to take a large joint angle.

In addition, in order to give a predetermined joint angle, the roller 5
It is necessary to make the chamfered portion 5A of the roller 5 somewhat large, and in that case, the effective contact length of the inner surface of the roller 5 with the needle bearing 4 becomes smaller, and the local surface pressure acting on the inner surface of the roller 5 increases, causing the roller 5 to Durability at the inner diameter portion of the tube deteriorates.

In addition, when the first shaft 1 and the second shaft 8 have a joint angle and transmit torque, the needle bearing 4 is is pushed in one direction, and one end surface of the needle bearing 4 rotates on its own axis while being pressed against one of the retainers 9 and 12, and also revolves around the trunnion 3, so that the revolution speed at the one end side of the needle bearing 4 is smaller than the revolution speed at the other end, and the needle bearing 4 revolves around the trunnion 3 with its axis skewed from its normal state, allowing the needle bearing 4 to rotate and revolve smoothly. Therefore, the durability of the transfer surface of the trunnion 3 cannot be maintained satisfactorily.

Furthermore, in order to assemble the trunnion end in the tripod joint as described above, with the roller 5 loosely inserted into the trunnion 3, a large number of twenty-one dollar bear tongues 4 are inserted one by one between the two, and then the retainer 9 is attached to the snap ring. 11 to the end of the trunnion 3, there is a problem in that the assembly requires a large number of man-hours.

This idea was developed in consideration of the above-mentioned conventional problems, and allows the roller to be moved in the axial direction to a large extent, allowing a large joint angle, and reducing the contact surface pressure between the inner surface of the roller and the needle bearing. It is an object of the present invention to provide a tripod joint that has good durability and can reduce the number of parts and assembly man-hours.

In order to achieve the above-mentioned object, this invention has three trunnions each extending radially from a tripod shaft, and a roller having an outer spherical surface is rotatably and axially movably supported via a needle bearing. In a tripod joint formed by fitting this roller into a roller groove forming an inner spherical surface of a tulip shaft, a shell having a U-shaped cross section formed separately from the roller is fixed to the inner peripheral surface of the roller,
The needle bearing is held within the shell.

Hereinafter, embodiments of this invention will be described with reference to the drawings.

FIG. 3 is an explanatory diagram showing the l-runion end structure in one embodiment of the tripod joint according to the invention.

The roller 21 is rotatably and axially movably supported on the outer periphery of the trunnion 3, with a shell 23 holding a large number of 21-dollar bear tongues 22 fixed to its inner periphery by press-fitting or the like.

The shell 23 is made by carburizing and quenching a steel plate, and uses its inner circumferential surface as a transfer surface for the needle bearing 22, and also bends the inner circumferences of both sides to the inside of both ends 22A of the needle bearing 22 to form a lip portion 23A. The needle bearing 22 is formed to have a U-shaped cross section, and when assembled to the trunnion 3, the needle bearing 22 at the front can be prevented from falling off from the shell 23.

The lip portion 23A is formed as thin as the strength of the material allows.

Further, it is preferable that the axial width of the shell 23 is smaller than the axial width of the roller 21 so that it can be secured to the inner peripheral surface of the roller 21 even when the roller 21 moves in the axial direction. .

Furthermore, the gap between the inner end side step part of the trunnion 3 and the inner end surface of the roller 21 in the zero joint angle state is as follows: The size is set to allow movement in the axial direction without interfering with the

Next, the operation of the above embodiment will be explained.

The roller 21 is attached to the outer periphery of the l-runion 3 with a needle bearing 22 on its inner periphery through a shell 23 .

The transmitted l-lux received between the first shaft and the second shaft is transmitted via the trunnion 3, the needle bearing 22, the shell 23, and the roller 21.

Further, when torque is transmitted with a joint angle between the first shaft and the second shaft, the roller 21 rotates and moves in the axial direction, and the needle bearing 22
rotates and revolves while moving in the axial direction together with the roller 21.

According to the above embodiment, the movement of the roller 21 in the axial direction is as follows:
Since it is not restricted by a retainer or the like provided at the end of the trunnion 3, it is possible to set a large allowable movement amount in the axial direction, and a large joint angle can be obtained.

Further, since no chamfered portion is formed on the inner end surface of the roller 21, the surface pressure acting on the inner surface of the roller 21 is reduced and its durability is improved.

Further, since the needle bearing 22 is able to move in the axial direction while being integrated with the roller 21 and the shell 23 when the roller 21 moves in the axial direction, a large thrust force acts on one end surface of the needle bearing 22. Without this, smooth rotation and revolution are maintained, and the durability of the transfer surfaces of the needle bearing 22 and the trunnion 3 is improved.

Furthermore, since the needle bearing 22 is prevented from falling off during assembly by the lip portion 23A of the shell 23, it is necessary to provide a retainer or the like at the end of the I-runion 3 as a means to prevent the roller 21 from falling off. Therefore, the number of parts can be reduced and the workability of the assembly can be improved.

As described above, in this invention, a roller having an outer spherical surface is rotatably and axially movably supported via needle bearings on three trunnions each extending in the radial direction from the tripod shaft. In a tripod joint in which a roller is fitted into a roller groove forming an inner spherical surface of a tulip shaft, a shell having a U-shaped cross section formed separately from the roller is fixed to the inner peripheral surface of the roller, and the Since the needle bearing is retained, there is no need for a retainer or chamfer as in the past, and by forming the shell separately from the roller, it is possible to form the shell from a high-strength material such as a steel plate. This makes it possible to form the lip part of the shell thinner, allowing a large joint angle to be set in the assembled state, and improving the durability of the tripod, needle bearing, and roller. , the number of parts and the number of assembly steps are reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a general tripod joint, Fig. 2 is a sectional view showing the end structure of a conventional tripod joint, and Fig. 3 is an embodiment of the tripod joint I according to this invention. 4 is a sectional view showing the end structure, and FIG. 4 is an enlarged sectional view showing the main part of FIG. 3. 3...trunnion, 21...roller,
22... Needle bearing, 23...
shell.

Claims (1)

[Scope of utility model registration request] 3 each extending radially from the tripod axis
In an I-report joint, a roller having an outer spherical surface is rotatably and axially movably supported on a book trunnion via a needle bearing, and this roller is fitted into a roller groove forming an inner spherical surface of a tulip shaft. A tripod joint, characterized in that a shell having a U-shaped cross section formed separately from the roller is fixed to the inner peripheral surface of the roller, and the needle bearing is held within the shell.