JPS5942504Y2 - universal joint - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a universal joint used for a drive shaft of an automobile, etc., and particularly relates to a type of universal joint in which a cross shaft is attached via a needle bearing.

Conventionally, various improvements have been made to this type of universal joint to improve its useful life.

This idea is also aimed at improving its useful life.

Prior to explaining this invention, a brief explanation will be given of the wear of the cross shaft, which is closely related to the service life, with reference to the first and second drawings.

The cross shaft 10 receives the rotational force of the drive shaft 20 via the support portions 21 and 22, and transmits the rotational force to the driven shaft 30 via the support portions 31 and 32.

Therefore, the rotational force of the drive shaft 200 may cause minute stress and strain on the support portion.

Further, when assembling the trunnion 11 and the bearing cup 12 to form a universal joint, it is difficult in manufacturing to provide no clearance between them.

If rotational force is applied to a state where there is a slight tolerance for this reason, the bearing cup 12 and trunnion 11
It is thought that the two contact each other in a distorted state as shown in FIG. 2, and as a result, wear occurs at the parts indicated by A, B, and C in the figure.

However, FIG. 2 is exaggerated for clarity of drawing.

This invention provides a trunnion shape that realizes reasonable and stable contact even in the above-mentioned situations.

Next, an embodiment of this invention will be explained with reference to FIGS. 3 and 4.

10 is a cross shaft, 11 is a trunnion, 12 is a bearing cup, and 13 is a needle bearing.

The trunnion 11 is fitted into a needle bearing 13 housed in a bearing cup 12, forming a universal joint.

The shape of the trunnion 11 is as follows.

First, as shown in Figure 4, set the center axis of the trunnion at 0-
O1 The contact line between the needle bearing and the trunnion in the normal contact state is x-x<o-o and X-X is parallel), (i) The plane containing the end face of the trunnion tip perpendicular to -0 is Y- Y
I will pray for you.

A gently tapered surface 112 forming a small angle p with respect to Y-Y is provided on the outer edge of the flat end surface 110 at the tip of the trunnion 11 from a position P slightly away from O-O.

Further, a tapered surface 116 is provided on the cylindrical side surface 114 starting from a position Q that is slightly away from the leading edge and forming a small angle q with respect to X-X.

Further, the base of the side surface 1140 is also provided with a gently tapered surface 118 that forms a small angle r with respect to X--X from a position R that is somewhat closer to the tip than the end of the needle bearing 13.

This is done in the opposite direction to the tapered surface 116, so that the shaft diameter of the trunnion becomes thinner as it approaches the base, and then the shaft diameter is restored with a smooth curved surface.

The part between Q and R shown in the figure is the contact part that comes into contact with the needle bearing 13 in the normal state, and the length in the axial direction is about 115 to 1/3 of the total length of the trunnion, but each part It is affected by the accuracy and rigidity of

In addition, the small angles p, q, and r mentioned above are usually 1~
The angle is approximately 5°, but it is affected by the precision and rigidity of each part as well as the length of the contact portion.

In the above explanation and drawings, the taper was explained using a conical taper as a model, but in this invention, it is not limited to a conical taper, but a smooth tapered curved surface, such as a spherical surface, can be used as a conical taper. There is no problem in adopting it instead.

That is, the five tapers shown in this invention also include tapers with smooth curved surfaces.

Furthermore, in the above description, explanations and illustrations of things that are not directly related to the contents of the invention, such as oil seals, etc., have been omitted, but they will be provided as appropriate when implementing this invention.

Describe the action.

"FIG. 3" shows the normal state in which the trunnion 11 is not twisted.

It contacts the needle bearing 13 between QP of the side surface 114, and contacts the bottom of the bearing cup 12 between the flat portions PP of the end surface 110, and is supported.

However, if the trunnion 11 is twisted and tilted within the bearing cup 12 (see FIG. 2), the following will occur.

In other words, when there is little twisting (less tilting force),
The trunnion has a bearing cup 12 at P and also Q,
P contacts the needle bearing 13, respectively.

Furthermore, as the twist becomes larger, the tapered surface 11
They come into contact at 2,116 degrees and 118 degrees.

Note that as use continues, the PtQtR will wear out a little and its corners will become rounded.

Then the contact becomes more stable.

Those parts may be rounded from the beginning without waiting for wear.

Effects of the invention (1) Angles p, q, r &' of each tapered surface
! /Js, the angle between the tapered surface and the end surface 110 or side surface 114 in P, Q, and R becomes a large obtuse angle close to 180°.

Therefore, even if these P, Q, and H contact the bearing cup 12 or the needle bearing 13, the conventional "second
Figure A and B.

Unlike contacting at an angular place like C, there is less chance of mutual wear.

(2) As mentioned above, while using these P.

The QtH corner disappears and it takes on a kojidoko color.

This will further reduce wear.

(3) When the tapered surfaces make contact, there is even less wear.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a universal joint using a cross shaft, Fig. 2 is an explanatory diagram of the contact state of the conventional trunnion in a twisted state within the bearing cup, and Fig. 3 is an illustration of the main parts of the embodiment of the present invention. The longitudinal sectional elevational view, FIG. 4, is an explanatory diagram of the shape of the trunnion. 10... Jushashaft, 11... Trunnion, 12... Bearing cap, 13...
・・Needle bearing, 110・・End face, 114・
... Clear surface, 112, 116 and 118 --- Tapered surface.

Claims (1)

[Claims for Utility Model Registration] In a universal joint in which a trunnion 11 of a cross shaft 10 is fitted into a bearing cup 12 containing a needle bearing 13, an outer edge of a flat end surface 110 at the tip of the trunnion 11;
Tapered surfaces 112°, 116, and 118 with gentle angles are provided at the tip and base of the cylindrical side surface 114, respectively, so that when the trunnion 11 and the bearing cup 12 are twisted, the tapered surfaces 1, 12, 11'6 , 118° or at the boundary between the tapered surface 112 and the end surface 110, and between the tapered surfaces 116 and 118 and the side surface 114, the trunnion 11 contacts the bottom surface of the bearing cup 12 and the needle bearing 13. universal joint.