JPH072644U - Cross joint - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a cruciform shaft joint capable of minimizing the dynamic frictional force generated between the end faces of the cruciform shaft shaft relative to the inner bottom surface of the bearing cup in the axial direction. In a cross joint in which the shaft end surface (12A) of the cross shaft (11) is supported by the bottom surface of the bearing cup (1), a protrusion in which the cross shaft end surface (12A) is provided at the center of the bottom of the bearing cup so as to be supported. Part (1A) and the bottom part (1
C) and a plurality of protrusions (2) for maintaining a minute gap between the shaft end face (12B) and the shaft end face (12B).

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cross joint, and more particularly, to a free cross joint in which forks of an input / output shaft are connected to each other via a cross member (spider).

[0002]

[Prior art]

 In this type of cross joint used for power transmission shafts of automobiles, a needle bearing held by, for example, a bearing outer cylinder (bearing cup) is provided between the journal shaft of the spider and the fork yoke of the shaft. The peripheral portion of the cup-shaped bottom portion of the bearing cup is fixedly supported in the support hole of the yoke through caulking of the yoke or a spring ring or the like. By the way, in the case of such a cross joint, if 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 and impairing the function of the joint. Therefore, as an example in which the obstacle caused by the generation of the frictional force is suppressed, there is known, for example, the one shown in FIG. 7 disclosed in JP-A-47-43740.

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

FIG. 8 shows such a bearing cup 13 taken out. As shown in this figure, a circular protrusion 13A is provided at the center of the bottom, and the journal shaft 12 end is provided on this circular protrusion 13A. The protrusions 12A provided at the corresponding positions of the parts are configured to come into contact with each other. Further, in this example, the bearing cup 13 having such a shape is formed by drawing a thin plate, and accordingly, the side surface portion 13B, the circular protrusion 13A, and the circular protrusion 13A around the side portion 13B are raised. The bottom portion 13C and the corner bottom portion 13D are formed to have substantially the same thickness. Thus, by utilizing the spring property of the raised bottom 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 is suppressed. Is being pursued.

[0005]

[Problems to be solved by the device]

 However, in the cruciform shaft coupling configured as in the above-mentioned conventional example, the circular protrusion 13A provided on the bottom of the bearing cup 13 has a limited area to support the corresponding protrusion 12A at the tip of the journal shaft. Therefore, the generation range of frictional force due to dynamic friction between them is limited, but the frictional force per area increases rather. Further, since the thickness of the raised bottom portion 13C is also formed to be the same as the thickness of the other portions of the bearing cup 13, the rigidity of the raised bottom portion 13C overcomes the spring property and does not function as a spring.

The object of the present invention is to minimize the dynamic frictional force generated during the relative displacement of the journal shaft end surface with respect to the inner bottom surface of the bearing cup in order to eliminate the above-mentioned conventional drawbacks. It is to provide a possible cross joint.

[0007]

[Means for Solving the Problems]

 In order to achieve such an object, a first aspect of the present invention has a bearing cup fitted in a bearing hole provided in the yoke of the shafts to be connected, and the end surface of the cross shaft is the above-mentioned. In a cross joint designed to be supported by the bottom surface of the bearing cup, a protrusion provided to support the end face of the shaft of the cross shaft at substantially the center of the bottom of the bearing cup, and the periphery of the protrusion. A projection that is disposed on the bottom portion and that maintains a minute gap between the bottom surface and the end surface of the shaft.

A second aspect of the present invention has a bearing cup fitted in a bearing hole provided in the yoke of the shafts to be connected, and the end face of the cross shaft is defined by the bottom face of the bearing cup. In the cruciform shaft joint so as to be supported, the bearing cup has a protrusion at substantially the center of the bottom of the bearing cup so that the end face of the shaft of the cruciform can be supported, and the thickness of the bottom portion around the protrusion. Is formed thinner than the thickness of the protrusion.

[0009]

[Action]

 According to the first aspect of the present invention, the end face of the shaft of the cross shaft is supported by being brought into contact with the protrusion formed at the center of the bottom portion of the bearing cup. If the sliding contact load between the shaft and the part becomes excessive, the slight load on the bottom of the bearing cup causes the end face of the cross shaft around the circular protrusion to be supported by the protrusion, and the above load will be applied to the protrusion. It is possible to prevent seizure between both contact surfaces due to frictional force due to excessive sliding contact load.

In addition, according to the second aspect of the present invention, since the peripheral bottom portion of the protrusion of the bearing cup is formed thin, the spring constant of this portion that functions as a leaf spring supporting the protrusion is The effect is the same as when the load is lowered, and the surrounding bottom allows the protrusion to easily support the generated load, and in the same way contributes to the prevention of seizure.

[0011]

【Example】

 Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 shows an embodiment according to the first mode of the present invention. Here, 1 is a bearing cup according to the present invention, 1A is a circular protrusion provided at the center of the bottom of the bearing cup, and 2 is a hemispherical protrusion provided on the raised bottom 1C of the bearing cup 1. In this example, a plurality of such protrusions 2 are arranged at evenly spaced positions on the inner bottom surface of the raised bottom 1C as shown in FIG. 2, and as shown in FIG. A slight gap is maintained between the tip of the protrusion 2 and the end face 12B of the journal shaft 12 in a state in which the protruding face 12A provided on the bearing abuts on the circular protrusion 1A provided on the bottom of the bearing cup 1. To In addition, 1B shows the side surface part of the bearing cup 1, 1D shows the corner bottom part, respectively. Further, in this example, as shown in FIG. 1, such a bearing cup 1 is press-fitted into the hole 10A of the yoke 10 and then the end edge of the hole 10A is caulked toward the corner bottom 1D, whereby the needle bearing 15 The journal shaft 12 is held by the yoke 10 via.

In the cross joint configured as described above, when the load generated by the contact between the projecting surface portion 12A provided at the journal shaft end and the circular projecting portion 1A of the bearing cup 1 is low, the sliding contact of both of these causes The generated dynamic friction force per unit area is also suppressed to a low level. When the above load becomes high, the spring property of the raised bottom 1C causes this portion to bend downward in FIG. 1, causing the plurality of protrusions 2 to come into contact with the end surface 12B of the journal shaft 12 and raise the raised bottom. Part of the load is carried by the bottom portion 1C. Therefore, the frictional force acting per unit area between the circular protrusion 1A and the protrusion 12A does not increase significantly, and wear and seizure during that period can be prevented.

In the present embodiment, a plurality of hemispherical projections 2 are arranged at positions evenly spaced in the circumferential direction of the raised bottom portion 1C, but such a plurality of projections 2 are provided on the raised bottom portion 1C although not shown. It may be appropriately dispersed and arranged, and the gap between the tip of the projection 2 and the journal shaft end surface 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 an embodiment according to the second mode of the present invention. In the above-described embodiment, the circular projection 1A, the side surface 1B, the raised bottom portion 1C and the corner bottom portion 1D of the bearing cup 1 are all formed to have the same size on the premise of the drawing of the sheet metal. In the present embodiment, in contrast to the embodiments described so far, only the raised bottom portion 1C is formed thinner than other portions, so that the spring property of the raised bottom portion 1C can be used more effectively. Is. The rest of the configuration except the bearing cup 1 is the same as that of the above-described embodiment, so its explanation is omitted and only the bearing cup 1 will be explained with reference to FIG.

Originally, in the bearing cup 1, the circular projection 1A, the side surface 1B, and the corner bottom portion 1D are portions that do not need to be formed to be particularly thin from the viewpoint of functionality, but as the raised bottom portion 1C, In the present invention, since the springy function is utilized in the present invention, a thickness suitable for that is preferable, and it is desirable that the thickness be thin. Therefore, in this embodiment, when the thickness of the circular protrusion 1A is TA, the thickness of the side surface portion 1B is TB, the thickness of the raised bottom portion 1C is TC, and the thickness of the corner bottom portion 1D is TD,

[0017]

## EQU00001 ## 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 protrusion 1A of the bearing cup 1 with which the protrusion 12A of the journal shaft 12 abuts has a thickness that can withstand a sufficient load. On the other hand, since the springiness of the raised bottom portion 1C around it can be effectively made to function, the circular protrusion 1A can be displaced downward according to the above load, and the circular protrusion 1A and the journal can be displaced. It is possible to prevent seizure due to excessive dynamic frictional force generated between the shaft projection surface portion 12A.

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

By the way, in any of the embodiments of the above-mentioned embodiments, no problem concerning the lubrication of the needle bearing 15 itself was mentioned. However, such a bearing cup 1 is generally filled with a lubricant, and such a lubricant film is evenly formed without being cut between the journal shaft end surface 12A and the circular projection 1A slidingly contacting the end surface 12A. It is desirable to be kept at. FIG. 6 shows an embodiment in consideration of this point. Here, 3 is a lubricant holding hole (hereinafter referred to as a concave hole) formed in the circular protrusion 1A at the bottom of the bearing cup. In this example, the concave hole 3 is formed into a pointed square hole by press working with the punch 20 as shown in (B), but it is not limited to the square hole and, for example, a round hole. It may be.

However, by providing the stepped shoulder portion 20A of the punch 20 with the roundness R, as shown in this figure, the gap between the peripheral portion of the recessed hole 3 and the surface of the circular protrusion 1A is increased. Can be formed on a smooth surface, and when the punch 21 as shown in (C) is used, the formation of the flash 3B that tends to be formed around the concave hole 3A is prevented. By forming the concave holes 3 as shown in (B) by appropriately dispersing them on the surface of the circular protrusion 1A as shown in (A), the lubricant can be retained in these concave holes 3. For example, by applying this embodiment to a cross shaft joint as shown in FIGS. 1 and 3, the oil film is not cut off between the journal shaft projecting surface portion 12A and the seizure is further prevented. be able to.

Further, in the present embodiment, the plurality of recessed holes 3 are distributed and arranged in the lattice-shaped positions on the circular protrusions 1A of the bearing cup 1A, but the arrangement of the recessed holes 3 is limited to such a lattice-shaped position. It is sufficient to disperse them appropriately considering the degree of sliding contact. However, if a continuous long groove or the like is provided to hold the lubricant, the rigidity of the circular protrusion 1A itself is reduced, so it is not desirable unless the plate thickness of the circular protrusion 1A is sufficient.

[0023]

[Effect of device]

 As described above, according to the first aspect of the present invention, the protrusion formed so as to support the end face of the shaft of the cross shaft at substantially the center of the bottom portion of the bearing cup, and the periphery of the protrusion. Supporting surface (projection) of the bearing cup that supports the end of the journal shaft due to manufacturing tolerances, operating conditions, etc., because it is provided at the bottom and has a protrusion that maintains a small gap with the end face of the shaft. Even if the load applied to the load increases, a part of the load will be shared and carried by the protrusions provided around the support surface, and the dynamic frictional force generated by the excessive load will be Therefore, it is possible to prevent the seizure between the both.

According to a second aspect of the present invention, the bearing cup is fitted in the bearing hole provided in the yoke of the shafts to be coupled, and the end face of the cross shaft is the bearing cup. In a cross joint made to be supported by a bottom surface, a protrusion is provided substantially in the center of the bottom of the bearing cup so as to support the end face of the cross shaft, and the bottom around the protrusion is provided. Is formed thinner than the thickness of the protrusion, so that the spring constant of the bottom raising bottom that functions as a leaf spring and continues to the surrounding portion of the above-mentioned support surface (protrusion) is reduced. It is possible to suppress an increase in the load applied to.

Thus, according to the present invention, it is possible to prevent seizure that occurs between the bottom surface of the bearing cup and the end surface of the journal shaft in either the first or second embodiment, and in turn, it is possible to prevent seizure. It is possible to contribute to expanding the range of manufacturing tolerances and assembly tolerances of each part that constitutes the cross joint.

[Brief description of drawings]

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

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

FIG. 3 is a sectional view showing a configuration of an embodiment according to a second mode of the present invention.

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

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 the line AA (B) and a cross-sectional view (C) of a comparative example, which are applicable to both the first and second forms of the present invention. It is an explanatory view shown by.

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]

 1 Bearing Cup 1A Projection (Supporting Surface) 1B Side Surface 1C Bottom Raised Bottom 1D Corner Bottom 2 Projection 3 Recessed Hole 10 Yoke 10A Hole 11 Spider 12 Journal Shaft 12A Projection 12B End 14 Needle 15 Needle Bearing 20 Punch 20A Shoulder

Claims (2)

[Scope of utility model registration request] 1. A cross shaft joint having a bearing cup fitted in a bearing hole formed in the yokes of the shafts to be connected so that the end surface of the shaft of the cross shaft is supported by the bottom surface of the bearing cup. In the center of the bottom portion of the bearing cup, a protrusion provided to project the end face of the shaft of the cross shaft so as to be supported, and a small portion between the end face of the shaft, which is disposed on the bottom portion around the protrusion. A cross joint having a projection for maintaining a clearance. 2. A cross shaft joint having a bearing cup fitted in a bearing hole provided in the yokes of the shafts to be connected so that the end surface of the shaft of the cross shaft is supported by the bottom surface of the bearing cup. In the above-mentioned bearing cup, a projection is provided substantially in the center of the bottom of the bearing cup so that the end surface of the shaft of the cross shaft can be supported, and the thickness of the bottom around the projection is formed thinner than the thickness of the projection. A cross joint that is characterized.