JPH0514649U - Universal joint - Google Patents

Abstract

(57) [Summary] [Purpose] Without causing local stress concentration on the inner surface of the bearing case due to line contact by a small diameter needle roller.
To obtain a maintenance-free universal joint that can disperse stress concentration and thus prolong the life of the bearing case. [Structure] The outer surface of the cross pin shaft portion 2 has a truncated cone shape,
A frustoconical cage 4 in which the needle rollers 3 are obliquely arranged in the circumferential direction is fitted and inserted into the outer side of the cross pin shaft portion 2, and a tapered taper is provided between the needle roller 3 arranged in the cage 4 and the bearing case 5. A taper bush 6 having a tapered frustoconical inner surface and a cylindrical outer surface and slidably contacting the needle roller 3 and the bearing case 5 in an oblique arrangement.
Intervene.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 According to the present invention, a pair of shaft portions, which are diametrically opposed to each other through a bearing case accommodating a needle roller, are respectively rotatably attached to four shaft portions of a cross pin on a drive shaft side yoke and a driven shaft side yoke. It relates to universal joints to be connected.

[0002]

[Prior Art]

 In such a conventional universal joint, as shown in FIG. 3, the needle roller 40 is arranged substantially parallel to the axis of the cross pin shaft portion in the annular gap in the circumferential direction between the cross pin shaft portion 20 and the bearing case 30. It was arranged directly so that it could roll freely.

[0003]

[Problems to be solved by the device]

 But, For example, the driving side yoke 50 and the driven side yoke 51 of the universal joint are For example, in one direction around the central axis line at the intersection of the cross axis lines of the cross pins that are orthogonal to each other and form an angle of 0 to 5 °. When rotating in the direction indicated by arrow A in FIG. 3, Due to the clearance between the bearing case and the needle roller, The cross pin housing hole axis of the yoke and the cross axis do not match, Make an angle,  Therefore, While the needle roller 40 is pressure-bonded to the portion corresponding to the tip of the cross pin shaft portion 20 on a specific side surface of the bearing case 30 fixed to the yoke 50 or 51 (the portion surrounded by the circle B in FIG. 3), When the yoke 50 or 51 rotates once, The cross pin shaft portion 20 periodically reciprocates relative to the bearing case 30 over a total angle of 10 ° of + 5 ° to -5 °. Therefore, The needle roller 40 having a small radius that 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 ° of + 5 ° to −5 °.

For this reason, with the passage of time, continuous and periodic sliding of a slight angle occurs at the discontinuous stress concentration portion of the bearing case where the needle roller having a small radius (large curvature) makes line contact. The wear-resistant layer on the inner surface of the bearing case peels off into multiple striations, leading to rapid local wear and destruction of the bearing case.

Therefore, an object of the present invention is to disperse stress concentration on the inner surface of the bearing case without causing local stress concentration due to line contact by a small diameter needle roller, and thus It is to get a universal joint of maintenance free that can prolong the life.

[0006]

[Means for Solving the Problems]

 In order to achieve this object, the universal joint according to the present invention has a truncated cone-shaped cage in which the outer surface of the cross pin shaft portion is frusto-conical and the needle rollers are obliquely arranged in the circumferential direction. Between the needle roller and the bearing case, which are fitted on the outside of the cage and arranged in the cage, and the tapered cone-shaped inner surface of the truncated cone and the outer surface of the cylinder are arranged in the oblique arrangement. It is characterized by interposing a taper bush that slidably contacts the casing.

[0007]

[Action]

 According to this construction of the present invention, the driving side and the driven side of the universal joint are unidirectional about the central axis at the intersection of the crossing axes of the cross pins, which form an angle of 0 to 5 ° with each other. When the cross pin is rotated relative to the bearing case periodically relative to the bearing case over a total angle of + 5 ° to -5 °, a plurality of local line contact stress concentrations due to the needle roller are applied. Is a taper bush having a taper inner surface, and the bearing case is not subjected to a plurality of local line contact stress concentrations due to the needle roller.

Further, when the cross pin periodically rotates relative to the bearing case over a total angle of + 5 ° to −5 °, which is a total of 10 °, the axis of the cross pin shaft portion of the needle roller tilted and arranged in the cage. When the cross-pin shaft rotates in the direction opposite to the direction of the opening of the inclination parallel to the direction parallel to, the roller is pinched between the cross pin and the taper bush in the latter half of the rotation in this direction, and this taper The bush, together with the cage carrying the cross pins and needle rollers, slides relative to the outer bearing case.

On the contrary, when the cross pin shaft portion rotates in the direction of the opening which is inclined with respect to the direction parallel to the axis line of the cross pin shaft portion of the needle roller, the roller includes the cross pin and the taper bush in the entire stroke of the 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 tapered bush. At this time, the taper bush does not rotate relative to the outer bearing case, but remains stationary.

Therefore, the needle roller periodically with respect to the tip portion of the cross pin shaft portion on the specific side surface of the bearing case with respect to the bearing case, for example, over a total angle of 10 ° of + 5 ° to −5 °. Even if they rotate reciprocally, the taper bush rotates due to the biting of the needle roller over only a small angle of a part of the rotation in one direction. The bearing is rotated stepwise with respect to the bearing case, so that the stress concentration can be dispersed without causing local stress concentration in the line contact by the needle roller with respect to the bush and the bearing case.

[0011]

【Example】

 Next, preferred embodiments of the present invention will be described with reference to the drawings.

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

Further, similarly to the conventional cross pin shaft portion / 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 portion 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 partially cutaway side view (a) of the needle roller / cage assembly and an enlarged sectional view (b) taken along the line bb of the side view.

When the cross pin 1 periodically rotates relative to the bearing case 5 over a total angle of + 5 ° to −5 °, which is a total of 10 °, the cross pin shaft of the needle roller 3 tilted and arranged in the cage 4. When the cross pin shaft portion 2 rotates in the direction opposite to the opening direction α of the inclination with respect to the direction parallel to the axis of the portion 1, that is, in the direction of the arrow A, the needle roller 3 moves to the cross pin shaft portion 2 in the latter half of the rotation in this direction. The taper bush 6 is pinched between the taper bush 6 and does not move, and the taper bush 6 is slidably rotated together with the cage 4 carrying the cross pin shaft portion 1 and the need roller 3 with respect to the bearing case 5 on the outside thereof. .

On the contrary, when the cross pin shaft portion 2 rotates in the direction α of the opening which is inclined with respect to the direction parallel to the axis of the cross pin shaft portion 2 of the needle roller 3, that is, in the direction opposite to the arrow A, the rotation in this direction In the entire process, the needle roller 3 is not sandwiched between the cross pin shaft portion 2 and the taper bush 6, the needle roller 3 rolls with respect to the taper 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, but remains stationary.

Therefore, the needle roller 3 with respect to the tip portion of the cross pin shaft portion 2 on a specific side surface of the bearing case 5 extends from the bearing case 5 over a total angle of 10 °, for example, + 5 ° to −5 °. Even if the rollers relatively cyclically reciprocally rotate, the taper bush 6 rotates due to the biting of the needle roller 3 over only a slight angle of a very small part of the rotation in a certain direction. The needle roller 3 is stepwise rotated with respect to the needle roller cage 4 and the bearing case 5, so that the taper bush 6 and the bearing case 5 do not generate local stress concentration on the line contact by the needle roller 3 and generate stress. You can disperse your concentration.

[0018]

[Effect of the device]

 As described above, when the drive shaft side and the driven side form an angle α and the rotational drive force is transmitted through the cross pin, the cross axis of the cross pin forms an angle with the axis of the bearing case of the yoke. None, a certain side surface of the tip of the cross pin presses the inner surface of the bearing case, so a stress concentration part occurs on the inner surface of the bearing case, and when the yoke makes one rotation, the cross pin makes an angle of 2α with respect to the bearing case. Since it reciprocates cyclically over a wide range, high-speed rotation of the shaft exposes it to severe wear due to high-speed reciprocal cyclic sliding on a specific side surface of the cross pin tip. According to the present invention, however, it is not the small diameter needle roller that makes contact with the bearing case but the large diameter taper bush, so that the stress concentration is distributed over a wide range of the bearing case and the unidirectional movement is performed. Only for a small angle of rotation, the engagement of the needle roller causes rotation of the taper bush with respect to the bearing case, and there is no return rotary sliding, so the caper bush moves back and forth with respect to the bearing case. Since no sliding occurs and the bearing case is advanced in one direction at a minute angle, the degree of wear is extremely small. As a result, it is possible to disperse the fractured local parts on the inner surface of the conventional bearing case, dramatically extend the life of the bearing case, and provide maintenance-free operation.

[Brief description of 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.

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 bush 7 Thrust washer 8 Oil seal 50,51 Yoke

Claims (1)

[Scope of utility model registration request] 1. A pair of shafts, which are diametrically opposed to each other through a bearing case accommodating a needle roller, are respectively rotatable on four shafts of a cross pin on a drive shaft side yoke and a driven shaft side yoke. In the universal joint to be connected to, the outer surface of the cross pin shaft portion is frusto-conical, and the frusto-conical cage in which the needle rollers are arranged obliquely in the circumferential direction is fitted and inserted on the outside of the cross pin shaft portion. A taper having a tapered tapered frustoconical inner surface and a cylindrical outer surface between the 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 characterized by a bush.