JP2551827Y2 - Universal joint - Google Patents

Description

[Detailed description of the invention]

[0001]

In the present invention, a pair of diametrically opposed shaft portions are respectively mounted on four shaft portions of a cross pin via a bearing case for accommodating a needle roller, respectively, on a drive shaft side yoke and a driven shaft. The present invention relates to a universal joint rotatably connected to a side yoke.

[0002]

2. Description of the Related Art In such a conventional universal joint, as shown in FIG. 3, a needle roller 40 is attached to an annular gap in a circumferential direction between a cross pin shaft portion 20 and a bearing case 30 along an axis of the cross pin shaft portion. They were arranged almost parallel and rolling freely.

[0003]

However, the drive-side yoke 50 and the driven-side yoke 51 of the universal joint are at an angle of, for example, 0 to 5 degrees, and are centered at the intersection of the cross axes of the cross pins which are orthogonal to each other. When rotating in one direction around the axis, for example, in the direction indicated by arrow A in FIG. 3, due to the clearance between the bearing case and the needle roller, the axis of the cross pin receiving hole of the yoke does not match the axis of the cross, The needle roller 40 presses against a portion corresponding to the tip of the cross pin shaft portion 20 on the specific side surface of the bearing case 30 fixed to the yoke 50 or 51 (the portion surrounded by a circle B in FIG. 3). At the same time, when the yoke 50 or 51 makes one rotation, the cross pin shaft portion 20 is rotated with respect to the bearing case 30 over a total of 10 ° angles of + 5 ° to −5 °. Relatively reciprocally rotated to. Accordingly, the needle roller 40 having a small radius, which moves together with the cross pin, comes into contact with the bearing case 30 and periodically rolls and slides over a total angle of 10 ° from + 5 ° to −5 °.

[0004] For this reason, with the passage of time, in the discontinuous stress concentration portion of the bearing case where the needle roller having a small radius (having a large curvature) is in line contact, continuous periodic sliding at a small angle occurs in the bearing case. The abrasion-resistant layer on the inner surface of the case is peeled off in a plurality of stripes, and the wear rapidly progresses locally, leading to destruction of the bearing case.

Accordingly, an object of the present invention is to disperse the stress concentration without causing local stress concentration due to line contact by a small-diameter needle roller on the inner surface of the bearing case, thereby extending the life of the bearing case. There is a maintenance free universal joint that can be done.

[0006]

In order to achieve this object, a universal joint according to the present invention has a truncated cone in which the outer surface of a cross pin shaft is formed in a truncated cone shape, and the needle roller is disposed obliquely in a circumferential direction. A conical cage is inserted into the outside of the cross pin shaft, and a tapered frusto-conical inner surface and a cylindrical outer surface having a tapered taper are provided between a needle roller arranged in the cage and the bearing case. A taper bush that slidably contacts a needle roller and a bearing case that are arranged obliquely is interposed.

[0007]

According to this configuration of the present invention, the driving side and the driven side of the universal joint are at an angle of, for example, 0 to 5 °, and are formed around the central axis at the intersection of the cross axes of the cross pins perpendicular to each other. Drive in one direction and the end of the cross pin is +5 to the bearing case
When the cross pin rotates while periodically swinging over a total angle of 10 ° of ゜ to -5 °, it is the taper bush having the tapered inner surface that receives a plurality of local line contact stress concentrations by the needle roller. Yes, the bearing case is not subject to multiple local line contact stress concentrations by the needle roller.

Further, when the cross pin rotates while the end portion of the cross pin periodically swings over an angle of + 5 ° to −5 ° with respect to the bearing case for a total of 10 °, the needle disposed in the cage is inclined. When the cross pin shaft rotates in the direction opposite to the direction of the opening of the inclination with respect to the direction parallel to the axis of the cross pin shaft of the roller, the roller is pinched between the cross pin and the tapered bush in the latter half of the rotation in this direction. This taper bush slides with the cage carrying the cross pin and the needle roller relative to the outer bearing case.

Conversely, when the cross-pin shaft rotates in the direction of inclination opening with respect to the direction parallel to the axis of the cross-pin shaft of the needle roller, the roller moves between the cross-pin and the tapered bush during the entire rotation in this direction. , The needle roller rolls with respect to the bush, and the cage carrying the cross pin and the needle roller rotates relative to the taper bush. At this time, the taper bush does not rotate relative to the outer bearing case and maintains a stationary state.

Accordingly, the needle roller is periodically moved relative to the bearing case with respect to the tip portion of the cross pin shaft on a specific side surface of the bearing case over a total angle of, for example, + 5 ° to -5 °, for a total of 10 °. Even if reciprocating, the taper bush is rotated by the bite of the needle roller over only a small part of the rotation in one direction, and the taper bush is attached to the cross pin / needle roller cage and the bearing case. However, the pinch roller rotates intermittently, which causes local stress concentration of the line contact with the bush by the needle roller. Can be dispersed by surface contact with the bush.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a preferred embodiment of the present invention.

FIG. 1 shows a partial longitudinal section of a cross pin shaft portion 2 of a cross pin 1 of a universal joint according to the present invention. According to the invention, the outer surface of the cross pin shank 2 is frusto-conical with a slight taper. A frusto-conical needle roller cage 4 having a taper corresponding to the tapered taper of the outer surface of the cross pin in which the needle roller 3 is disposed obliquely is fitted around the cross pin shaft portion 2. According to the invention, the annular gap between the cross pin shaft / needle roller cage assembly and the bearing case 5 has a frusto-conical inner surface with a taper corresponding to the taper of the outer surface of the cross pin and the outer surface is cylindrical. A tapered bush 6 having a shape is interposed.

Further, similarly to the conventional cross pin shaft / bearing case, a thrust washer 7 is inserted between the top surface of the bearing case 5 and the top end surface of the cross pin shaft 2 to form an annular edge of the bearing case 5. An oil seal 8 is provided between the cross shaft 2 and the neck of the cross shaft 2.

FIG. 2 shows a side view (a) of the needle roller / cage assembly with a part cut away, and an enlarged sectional view (b) taken along the line bb of this side view.

The end of the cross pin 1 is a bearing case 5
When the cross pin 1 is rotated by swinging periodically over a total angle of 10 ° from + 5 ° to −5 °, the cross pin shaft 1 of the needle roller 3 disposed on the cage 4 is tilted. When the cross pin shaft 2 rotates in the direction opposite to the direction α of the inclination opening relative to the parallel direction, that is, in the direction of arrow A, the needle roller 3 moves between the cross pin shaft 2 and the taper bush 6 in the latter half of the rotation in this direction. The tapered bush 6 slides with the cage 4 carrying the cross pin shaft portion 1 and the needle roller 3 relative to the bearing case 5 on the outer side thereof.

Conversely, when the cross-pin shaft 2 rotates in the direction α in which the inclination of the needle roller 3 with respect to the direction parallel to the axis of the cross-pin shaft 2 is parallel, that is, in the direction opposite to the arrow A, the rotation in this direction is In the entire stroke, the needle roller 3 is not pinched between the cross pin shaft portion 2 and the tapered bush 6, the needle roller 3 rolls with respect to the tapered bush 6, and the cage 4 carrying the cross pin 1 and the needle roller 3 is tapered. It rotates relative to the bush 6. At this time, the taper bush does not rotate relative to the outer bearing case 5 and maintains a stationary state.

Therefore, the needle roller 3 is moved from the bearing case 5 by, for example, + 5 ° to the tip of the cross pin shaft 2 on a specific side surface of the bearing case 5.
Even if the relative reciprocating rotation is performed periodically over a total angle of 10 ° of −5 °, the taper bushing 6 of the taper bush 6 is formed by the biting of the needle roller 3 over only a small angle of one part of rotation in one direction. Due to the rotation, the taper bush 6 rotates intermittently with respect to the cross pin / needle roller cage 4 and the bearing case 5, which causes a local stress concentration of the line contact of the taper bush 6 with the needle roller 3. However, the stress concentration portion can be replaced by the rotation of the taper bush 6, and the stress concentration can be dispersed to the bearing case 5 by surface contact with the taper bush 6.

[0018]

As described above, when the drive shaft side and the driven side make an angle α and transmit rotational driving force via the cross pin, the cross axis of the cross pin is aligned with the axis of the bearing case of the yoke. Since an angle is formed and the specific side of the tip of the cross pin presses the inner surface of the bearing case, a stress concentration part occurs on the inner surface of the bearing case,
Furthermore, when the yoke makes one rotation, the cross pin slides in a reciprocating cycle over a range of an angle 2α with respect to the bearing case. Therefore, in a high-speed rotation of the shaft, a specific side of the tip of the cross pin is subjected to a high-speed reciprocating cycle sliding, and thus is exposed to severe wear. It is. However, according to the present invention, it is not the small-diameter needle roller but the large-diameter taper bush that comes into contact with the bearing case. Over only a small angle, the biting of the needle roller causes the taper bushing to rotate only with respect to the bearing case without any return rotational sliding, so that the caper bushing reciprocally slides with respect to the bearing case. Without this, the bearing is stepped in one direction by a small angle with respect to the bearing case, so that the degree of wear is extremely reduced. Therefore,
Breakage localities on the inner surface of the conventional bearing case can be dispersed, so that the life of the bearing case can be drastically extended and maintenance-free can be provided.

[Brief description of the drawings]

FIG. 1 is an enlarged side view showing a partial cross section of a cross pin shaft portion of a universal joint according to the present invention.

FIG. 2A is a partially cutaway side view of a tapered needle roller case of a universal joint according to the present invention, and FIG. 2B is an enlarged partial cross-sectional view of the needle roller.

FIG. 3 is a side view showing a partial cross section of a conventional universal joint.

[Explanation of symbols]

 1 Cross Pin 2,20 Cross Pin Shaft 3,40 Needle Roller 4 Needle Roller Cage 5,30 Bearing Case 6 Taper Bushing 7 Thrust Washer 8 Oil Seal 50,51 Yoke

Claims (1)

(57) [Scope of request for utility model registration] A pair of diametrically opposed shafts are rotatably mounted on a drive shaft side yoke and a driven shaft side yoke, respectively, on four shaft portions of a cross pin via a bearing case for accommodating a needle roller. In the universal joint to be connected to the above, the outer surface of the cross pin shaft portion is formed into a frusto-conical shape, and a frusto-conical cage in which the needle rollers are arranged obliquely in the circumferential direction is fitted outside the cross pin shaft portion. A taper having a tapered frusto-conical inner surface and a cylindrical outer surface between a needle roller arranged in a cage and the bearing case and slidably contacting the needle roller and the bearing case in the oblique arrangement. A universal joint with a bush interposed.