JP2605227Y2 - Cross shaft coupling - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cross joint, and more particularly, to a universal cross joint in which fork portions of an input / output shaft are connected to each other via a cross shaft member (spider).

[0002]

2. Description of the Related Art In a cross joint of this type used for a power transmission shaft of an automobile, a bearing outer cylinder (bearing cup) is provided between a journal shaft of a spider and a fork yoke of the shaft.
And a peripheral portion of a cup-shaped bottom of the bearing cup is fixedly supported in a support hole of the yoke via a caulking yoke or a spring ring or the like. ing. By the way, in the case of such a cross joint, when the shaft end of the journal shaft slides on the inner bottom surface of the bearing cup, a large frictional force acts between them, causing seizure or impairing the function of the joint. For example, Japanese Patent Application Laid-Open No.
FIG. 7 disclosed in Japanese Patent No. 43740 is known.

In FIG. 7, reference numeral 10 denotes a flange yoke provided at the shaft end of one shaft, 11 denotes a spider, 10A
Is a hole provided in the yoke 10 for supporting the journal shaft 12 of the spider 11; 13 is a bearing cup which holds the needle 14 around the journal shaft 12 and is fitted between the journal shaft and the flange yoke; Reference numeral 15 denotes a needle bearing composed of the needle 14 and the bearing cup 13 as described above, and reference numeral 16 denotes a sealing member provided to prevent the lubricant filled in the bearing cup 13 from leaking outside. .

FIG. 8 shows such a bearing cup 13 taken out. As shown in FIG. 8, a circular projection 13A is provided at the center of the bottom. Protruding part 12 provided at the corresponding position of the part
A is configured to touch. In this example, the bearing cup 13 having such a shape is formed by drawing a thin plate.
The raised bottom portion 13C and the corner bottom portion 13D raised together with the circular projection 13A and the surrounding circular protrusion 13A are all formed to have substantially the same thickness. Thus, by utilizing the spring property of the raised bottom portion 13C and supporting the journal shaft 12 by the circular protrusion 13A, the frictional force generated between the shaft end of the journal shaft and the bottom surface of the bearing cup 13 can be suppressed. It is planned.

[0005]

However, in the cross joint constructed as in the above conventional example, the bearing cup 1
3 has a limited area of the circular projection 13A provided at the bottom, and the corresponding projection 12A at the tip of the journal shaft is supported. Therefore, the range of generation of frictional force due to dynamic friction therebetween is limited. Instead, the frictional force per area increases. Also, since the thickness of the raised bottom 13C is formed to be the same as the thickness of the other parts of the bearing cup 13, the rigidity of the raised bottom 13C overcomes the spring property and does not function as a spring.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned disadvantages of the prior art by axially displacing the end surface of the journal shaft with respect to the inner bottom surface of the bearing cup and supplying / holding a lubricant. It is an object of the present invention to provide a cross joint capable of minimizing a dynamic friction force generated between the cup inner bottom surface.

[0007]

In order to achieve the above object, the invention according to claim 1 has a bearing cup fitted in a bearing hole provided in a yoke between shafts to be connected.
In a cross joint in which an end surface of a cross shaft is supported by a bottom surface of the bearing cup, the bottom portion of the bearing cup has flexibility and is protruded substantially at the center,
A projection whose end surface supports the end surface of the shaft of the cross shaft while being in surface contact therewith, and is disposed at the bottom around the projection,
Until the pressing force of the cross shaft against the bottom reaches a certain value, a minute gap is kept between the end surface of the shaft and the cross shaft when the pressing force of the cross shaft against the bottom becomes a certain value or more. And a projection that makes contact with the end face and the projection.

[0008]

[0009]

According to the first aspect of the present invention, the end surfaces of the shafts of the cross shaft are respectively supported in contact with the projections formed substantially at the center of the bottom of the bearing cup. When the sliding load generated between the protrusion and the protrusion is excessive, the end surface of the cross shaft around the circular protrusion is supported by the protrusion due to the slight bending of the bottom surface of the bearing cup. Is carried on the projection and the plurality of projections in a shared manner, and it is possible to prevent both contact surfaces from seizing due to frictional force due to an excessive sliding load.

[0010]

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 shows an embodiment of the first aspect of the present invention. Here, 1 is a bearing cup according to the present invention,
A is a circular protrusion provided at the center of the bottom, and 2 is a hemispherical protrusion provided on the raised bottom 1C of the bearing cup 1. In this example, such a plurality of protrusions 2 are disposed at equal positions on the inner bottom surface of the raised bottom portion 1C as shown in FIG. 2, and as shown in FIG. The gap between the tip of the projection 2 and the end surface 12B of the journal shaft 12 is maintained slightly while the projection 12A provided on the bottom of the bearing cup 1 contacts the circular projection 1A provided on the bottom of the bearing cup 1. . 1B is a side surface of the bearing cup 1,
1D shows the bottom of each corner. In this example,
As shown in FIG.
The journal shaft 12 is held by the yoke 10 via the needle bearing 15 by press-fitting the end of the hole 10A toward the corner bottom 1D.

In the cross joint constructed as described above, when the load generated due to the contact between the projection 12A provided at the end of the journal shaft and the circular projection 1A of the bearing cup 1 is low, the sliding contact between the two is made. The resulting dynamic frictional force per unit area is also reduced. In the case where the above load is increased, this portion bends downward in FIG. 1 due to the spring property of the bottom raising bottom 1C, so that the plurality of protrusions 2 come into contact with the end surface 12B of the journal shaft 12 to raise the bottom. A part of the load is carried by the bottom 1C. Therefore, the circular protrusion 1A
The frictional force acting per unit area between the protrusion and the protruding surface portion 12A does not significantly increase, and abrasion and seizure therebetween can be prevented.

In this embodiment, a plurality of hemispherical projections 2 are provided.
Are disposed at equal positions in the circumferential direction of the bottom-up bottom 1C.
And the clearance between the tip of the projection 2 and the journal shaft end face 12B may be appropriately set according to the radial distance to each installation position. Further, the protrusion 2 may be formed in an annular shape around the circular protrusion 1A.

FIG. 3 shows a second embodiment of the present invention. In the above-described embodiment, the circular projection 1A, the side surface 1B, the raised bottom 1C, and the corner bottom 1D of the bearing cup 1 are all formed to have the same dimensions on the premise that the sheet metal is drawn. In this embodiment, in contrast to the embodiments described above, only the raised bottom portion 1C is formed to be thinner than other portions, so that the spring property of the raised bottom portion 1C is used more effectively. is there. The other configuration except for the bearing cup 1 is the same as that of the above-described embodiment, so that the description thereof will be omitted, and the description will be given with reference to FIG.

Originally, in the bearing cup 1, the circular projection 1A, the side surface 1B, and the corner bottom 1D are portions which do not need to be formed particularly thin from the functional point of view, whereas the bottom raised bottom 1C is not necessary. In the present invention, since the function of the spring property is used, a thickness suitable for the function is preferable, and a thinner one is preferable. Therefore, in the present embodiment, when the thickness of the circular projection 1A is TA, the thickness of the side surface 1B is TB, the thickness of the raised bottom 1C is TC, and the thickness of the corner bottom 1D is TD.

[0017]

## EQU1 ## Each part was formed so that TA = TB = TD> TC.

In the cross joint having the bearing cup 1 configured as described above, the circular projection 1A of the bearing cup 1 against which the projection 12A of the journal shaft 12 abuts can have a sufficient thickness to withstand a sufficient load. On the other hand, since the spring property of the raised bottom 1C around it can be made to function effectively, the circular protrusion 1A can be displaced downward according to the load, and the circular protrusion 1A and the journal shaft protrusion are formed. 12A can be prevented from generating an excessive dynamic frictional force and seizing.

FIG. 5 shows, as a characteristic curve, the relationship between the load applied to the circular projection 1A of the bearing cup 1 and the displacement generated in the direction of the load, wherein C2 shown by a broken line is a conventional example. On the other hand, C1 shown by a solid line is according to the above embodiment. As shown in this figure, even with the same amount of displacement, a much smaller load is applied in the embodiment than in the conventional example.

By the way, in each of the embodiments described above, no problem concerning lubrication of the needle bearing 15 itself was mentioned. However, the bearing cup 1 is generally filled with a lubricant, and such a lubricant film is uniformly held without being cut off between the journal shaft end surface 12A and the circular projection 1A slidingly contacting the journal shaft end surface 12A. It is desirable to be done. FIG. 6 shows an embodiment taking this point into consideration. Here, reference numeral 3 denotes a lubricant holding hole (hereinafter referred to as a concave hole) formed in the circular projection 1A at the bottom of the bearing cup. In this example, the concave hole 3 is formed into a square hole having a sharp point by pressing with the punch 20 as shown in FIG. 3B, but the present invention is not limited to the square hole, and may be a round hole, for example. Good.

However, by providing the shoulder 20A having a step with the step 20 of the punch 20 used here with a roundness R, as shown in this figure, the gap between the periphery of the concave hole 3 and the surface of the circular projection 1A is formed. It can be formed on a smooth surface, and when the punch 21 as shown in FIG. 3C is used, the generation of the flash 3B which tends to be formed around the concave hole 3A is prevented. By forming the recesses 3 shown in (B) appropriately dispersed on the surface of the circular protrusion 1A as shown in (A), the lubricant is held in these recesses 3. For example, by applying the present embodiment to a cross joint as shown in FIGS. 1 and 3, the oil film is not cut between the journal shaft protruding portion 12A and the seizure between the journal shaft protruding portion 12A can be further prevented. Can be.

Further, in the present embodiment, the plurality of recesses 3 are dispersedly arranged at lattice positions on the circular projection 1A of the bearing cup 1A, but the arrangement of the recesses 3 is limited to such lattice positions. Instead, they may be appropriately distributed and arranged in consideration of the degree of sliding contact. However, arranging continuous long grooves or the like for holding the lubricant decreases the rigidity of the circular projection 1A itself, and therefore is not desirable unless the thickness of the circular projection 1A is sufficient.

[0023]

[Effect of the invention] As described above, the first aspect of the invention is as follows.
According to the embodiment, a projection is provided at a substantially central portion of the bottom of the bearing cup so as to support the end surface of the shaft of the cross shaft, and the projection is disposed on the bottom around the projection and has an end surface of the shaft. With a projection that keeps a small gap between them, the load applied to the support surface (projection) of the bearing cup that supports the journal shaft end may increase due to manufacturing tolerances and operating conditions. A part of the load is shared and carried by the projections provided around the support surface, preventing seizure between the two due to dynamic frictional force generated by excessive load. can do.

[0024]

Thus, according to the present invention, seizure occurring between the bottom surface of the bearing cup and the end surface of the journal shaft can be prevented in either the first mode or the second mode, and the cross shaft can be prevented. This can contribute to the expansion of the manufacturing tolerances and assembly tolerances of the components that make up the joint.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of an example according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the bearing cup shown in the embodiment of FIG.

FIG. 3 is a cross-sectional view illustrating a configuration of an embodiment according to the second aspect of the present invention;

FIG. 4 is an explanatory view showing a cross section of the bearing cup shown in the embodiment of FIG. 3;

5 is a characteristic curve diagram showing load-displacement characteristics between a bearing cup bottom surface and a journal shaft end surface according to the embodiment of FIG. 3 in comparison with a conventional example.

FIG. 6 is a plan view (A), a cross-sectional view taken along line AA (B), and a cross-sectional view (C) of a comparative example of another embodiment applicable to both the first and second embodiments of the present invention. FIG.

FIG. 7 is a cross-sectional view showing a configuration of a conventional example.

8 is a sectional view of a bearing cup shown in the conventional example of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bearing cup 1A Projection (support surface) 1B Side surface 1C Raised bottom 1D Corner bottom 2 Projection 3 Concave hole 10 Yoke 10A Hole 11 Spider 12 Journal shaft 12A Projection surface 12B End surface 14 Needle 15 Needle bearing 20 Punch 20A Shoulder

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-132126 (JP, A) JP-A-55-115625 (JP, A) Fully open 6-69443 (JP, U) Really open 25828 (JP, U) Japanese Utility Model 2-38526 (JP, U) Japanese Utility Model 3-55925 (JP, U) Japanese Utility Model Utility Model 3-53623 (JP, U) Japanese Utility Model Utility Model No. 57-109329 (JP, U) Japanese Utility Model Showa 55-158325 (JP, U) Japanese Utility Model Showa 55-36796 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16D 3/38-3/41

Claims (1)

(57) [Scope of request for utility model registration] 1. A cross joint having a bearing cup fitted in a bearing hole provided in a yoke of connected shafts, wherein an end surface of the cross shaft is supported by a bottom surface of the bearing cup. A protrusion is provided at the bottom of the bearing cup, and is provided substantially at the center thereof, the end surface of which supports the end surface of the shaft of the cross shaft while making surface contact with the protrusion, and the protrusion around the protrusion. Until the pressing force of the cross shaft against the bottom reaches a certain value, a minute gap is maintained between the shaft and the end surface of the shaft, and the pressing force of the cross shaft against the bottom becomes a certain value or more. A cross joint, wherein a projection is provided at which the end face of the cross shaft contacts the projection.