JP2005030481A - Cross shaft joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize the structure for improving sealability of a roller bearing 5 provided in a cross shaft joint 1 without increasing the cost. <P>SOLUTION: A seal 6 for sealing the roller bearing 5 is provided with a metal ring 10 to be installed in an opening side inner periphery of an outer ring cup 8, inner lips 11 and 12 to be fitted to an inner diameter side of the metal ring 10, and an outer lip 13 to be fitted to an outer end part of a cylinder part 10a of the metal ring 10. The inner lips 11 and 12 are brought in contact with a root side shoulder part 4b of a trunnion 4a. The outer end part of the cylinder part 10a of the metal ring 10 is arranged opposite to the root side shoulder part 4b of the trunnion 4a with a fine clearance 15. The outer lip 13 seals the fine clearance 15. With this structure, even if muddy water is splashed to the fine clearance 15, intrusion of the muddy water is prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cross joint that can be suitably used for various power transmission shafts provided in an automobile or the like.
[0002]
[Prior art]
For example, in the cross shaft joint used for the above-mentioned applications, it is necessary to improve the sealing performance of the roller bearing 82 attached to the trunnion 81 of the cross shaft 80 as shown in FIG.
[0003]
The roller bearing 82 is sealed with a seal 83. The seal 83 has a configuration in which two inner lips 85 and 86 are attached to the inner diameter side of the metal ring 84. On the other hand, on the base side of each trunnion 81 of the cross shaft 80, a shoulder portion 87 having a hem shape is provided, and an annular step portion 88 is further provided in a region near the outer diameter of the shoulder portion 87. Yes. The two inner lips 85 and 86 are in contact with the shoulder 87 on the base side of the trunnion 81, and the outer end of the cylindrical portion 89 of the metal ring 84 is an annular stepped portion 88 of the trunnion 81. Are opposed to each other with a minute gap 90 therebetween.
[0004]
As described above, the minute gap 90 formed in the outermost peripheral portion of the seal 83 has a labyrinth sealing effect, but can be formed between the metal ring 84 and the inner lip 86 of the seal 83 when muddy water or the like is applied violently. It can be said that muddy water easily enters the space, which is not preferable. On the other hand, although not shown, a circumferential groove is formed in the annular step portion 88 of the trunnion 81, and the outer end portion of the cylindrical portion 89 of the metal ring 84 of the seal 83 is inserted into the circumferential groove in a non-contact state. (See Patent Document 1).
[0005]
[Patent Document 1]
Japanese Utility Model Publication No. 46-29065 [0006]
[Problems to be solved by the invention]
In the above conventional example, although the sealing performance of the roller bearing 82 by the seal 83 can be improved, a circumferential groove has to be formed on the annular stepped portion 88 of the trunnion 81, so there is a concern that the processing cost is high.
[0007]
[Means for Solving the Problems]
The present invention is a cross shaft joint including a cross shaft including four trunnions and four roller bearings mounted on each of the trunnions, and each of the roller bearings includes an outer ring cup and the outer ring cup. A plurality of rollers arranged on the inner periphery and interposed between the inner peripheral surface of the outer ring cup and the trunnion outer peripheral surface, and the trunnion outer peripheral surface and the outer ring cup mounted on the opening side end of the outer ring cup A seal that seals the annular space between the metal ring, the metal ring that is attached to the inner periphery of the outer ring cup on the opening side, the inner lip that is attached to the inner end of the metal ring, An outer lip attached to the outer end of the metal ring, the inner lip contacts an annular curved surface part connecting the trunnion and the cross shaft main body, and the outer end of the metal ring is The cross-axis tiger And face each other with a small gap to the end face of the on-side, the outer lip, closes the minute gap, it is characterized in that.
[0008]
In the present invention, the minute gap between the outer end of the metal ring of the seal and the shoulder on the root side of the cross shaft trunnion is closed by the outer lip. Even if it takes, this mud becomes difficult to enter. In addition, since the circumferential groove as in the conventional example is not provided in the base side shoulder portion of the cross shaft trunnion, useless processing becomes unnecessary. Further, since the outer lip is provided so as to be substantially within the outer dimension of the seal, it is not necessary to expand the installation space for the seal.
[0009]
By the way, the outer lip may be in contact with the trunnion side end surface of the cross shaft main body in a state of being bent so as to open outward in the radial direction, thereby closing the minute gap.
[0010]
In this case, by bringing the outer lip into contact with the annular stepped portion, the minute gap is closed without a gap, so that the effect of preventing intrusion of muddy water or the like is enhanced.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a cross joint according to an embodiment of the present invention will be described in detail with reference to the drawings. 1 to 3 relate to an embodiment of the present invention, FIG. 1 is a perspective view of a cross joint according to the embodiment, and FIG. 2 is a cross-sectional view of a roller bearing provided in the cross joint of FIG. FIG. 3 is an enlarged view of a seal provided in the roller bearing of FIG. In these figures, 1 is a cross shaft joint, and 2 and 3 are yokes.
[0012]
The cross shaft joint 1 includes a cross shaft 4, a roller bearing 5, and a seal 6. On the other hand, each of the yokes 2 and 3 has a pair of projecting pieces 2a and 3a that face each other in parallel. The projecting pieces 2a and 2a are provided with through holes 2b and 3b on the same axis. Each trunnion 4a of the cross shaft 4 is fitted into the through holes 2b and 3b of the yokes 2 and 3 via the roller bearings 5, respectively.
[0013]
Hereinafter, the configuration of the cross joint 1 will be described in detail.
[0014]
The cross shaft 4 has four trunnions 4a whose free ends extend in the cross direction. On the base side of each trunnion 4a, a shoulder portion (annular curved surface portion) 4b having a flared shape that gradually increases in diameter is formed.
[0015]
Each shoulder 4b includes a steep slope 4b1 near the trunnion 4a and a gentle slope 4b2 smoothly connected to the steep slope 4b1. The overall surface shape of each shoulder 4b is a concavely curved shape.
[0016]
Each shoulder 4b further includes an annular step 4c in a region near its outer diameter. In other words, an annular step 4c that is lower than the gentle slope 4b2 is provided in a region closer to the outer diameter than the gentle slope 4b2 of each shoulder 4b. The annular step portion 4c includes a wall surface 4c1 along the axial direction of the trunnion 4a and a wall surface (end surface on the trunnion side) 4c2 along the radial direction of the trunnion 4a.
[0017]
The roller bearing 5 is attached to each trunnion 4 a of the cross shaft 4 and includes an outer ring cup 8, a plurality of needle rollers 9, and a seal 6.
[0018]
The outer ring cup 8 is formed in a bottomed cylindrical shape, and includes a cylindrical portion 8a and a disc-shaped bottom portion 8b. The outer ring cup 8 can be manufactured by, for example, pressing a steel plate, or can be manufactured by turning.
[0019]
The needle roller 9 is interposed between the inner peripheral surface of the cylindrical portion 8a of the outer ring cup 8 and the outer peripheral surface of each trunnion 4a of the cross shaft 4, and the outer peripheral surface of each trunnion 4a serves as an inner ring raceway. Thus, the inner ring surface of the cylindrical portion 8a of the outer ring cup 8 can be rolled as an outer ring raceway. On the opening side of the outer ring cup 8, that is, on the opening end of the cylindrical portion 8a, a thin portion 8c whose inner diameter is increased to be thin is provided.
[0020]
The seal 6 is attached to the inner periphery of the roller bearing 5 on the opening side of the outer ring cup 8 to prevent foreign matter from entering the roller bearing 5. The seal 6 has a configuration in which a first inner lip 11, a second inner lip 12 and an outer lip 13 made of an elastic body are attached to a metal ring 10.
[0021]
The metal ring 10 includes a cylindrical portion 10a and a flange portion 10b, and is configured by extending the flange portion 10b radially inward on one end side of the cylindrical portion 10a.
[0022]
The first inner lip 11 is attached to the inner peripheral edge of the flange 10b of the metal ring 10 so as to extend radially inward.
[0023]
The second inner lip 12 is attached to the inner surface of the flange portion 10b of the metal ring 10 so as to extend in the axial direction.
[0024]
The outer lip 13 is formed by extending the elastic thin film 14 covered on the inner periphery of the cylindrical portion 10 a of the metal ring 10, and protrudes in the axial direction from the end of the cylindrical portion 10 a of the metal ring 10. It is provided in the form.
[0025]
In this embodiment, the outer lip 13 is provided on the inner circumference of the cylindrical portion 10a of the metal ring 10 to expose the metal surface of the outer end surface of the cylindrical portion 10a. Is used as a pressing surface when the seal 6 is assembled.
[0026]
Such a seal 6 is incorporated into the roller bearing 5 by fitting the cylindrical portion 10a of the metal ring 10 into the inner peripheral surface of the thin portion 8c of the outer ring cup 8 by press fitting. The roller bearing 5 incorporating the seal 6 in this manner is attached to the trunnion 4a of the cross shaft 4. In this state, the relationship between the seal 6 and the trunnion 4a will be described.
[0027]
First, the first inner lip 11 of the seal 6 is brought into contact with the steep slope 4b1 of the shoulder 4b of the trunnion 4a from the radial direction. The second inner lip 12 is in contact with the gentle slope 4b2 of the shoulder 4b of the trunnion 4a from the axial direction. Furthermore, the outer end portion of the cylindrical portion 10a of the metal ring 10 is opposed to the annular step portion 4c provided in each trunnion 4a with a minute gap 15 therebetween. Specifically, as shown in FIG. 3, the outer end surface of the cylindrical portion 10 a is attached to the wall surface 4 c 2 along the radial direction of the annular stepped portion 15, and to the inner peripheral surface of the outer end portion of the cylindrical portion 10 a. Since the thin film 14 is opposed to the wall surface 4c1 along the axial direction of the annular step portion 15 in a non-contact manner, the minute gap 15 is bent 90 degrees as shown in FIG. The outer lip 13 is in contact with the wall surface 4c2 along the radial direction of the annular step portion 4c provided in the trunnion 4a from the axial direction. Therefore, the outer lip 13 is a wall that closes the above-described minute gap 15 without gaps. It becomes like this.
[0028]
In the process of assembling the roller bearing 5 to the trunnion 4a, the outer lip 13 bends outward in the radial direction by rounding the intersection of the wall surface 4c1 along the axial direction and the wall surface 4c2 along the radial direction in the annular stepped portion 4c. Thus, the surface is brought into contact with the wall surface 4c2 along the radial direction of the annular step portion 4c. In FIG. 3, the state before bending of the outer lip 13 is shown by a broken line. In addition, although not shown, a lubricant such as grease is present in the space between the first inner lip 11 and the second inner lip 12 and the space surrounded by the second inner lip 12, the metal ring 10, and the outer lip 13. Enclosed.
[0029]
As described above, the minute gap 15 is formed between the metal ring 10 of the seal 6 and the annular step portion 4 c of the trunnion 4 a, and the minute gap 15 is closed with the outer lip 13 of the seal 6. Therefore, even if muddy water is violently applied to the minute gap 15 described above, it is difficult for the muddy water to enter the space where the two inner lips 11, 12 are arranged from the minute gap 15. As a result, the sealing performance of the roller bearing 5 by the seal 6 can be improved, so that the deterioration of the lubricant inside the roller bearing 5 can be prevented and the life of the roller bearing 5 can be improved. Is also connected. The outer lip 13 maintains the effect of closing the minute gap 15 even if it is worn over the course of use, so that the sealing performance of the roller bearing 5 can be maintained over a long period of time.
[0030]
In addition, unlike the conventional example, the cross shaft 4 is not processed, which is advantageous in reducing the cost. Further, since the outer lip 13 is provided so as to be substantially within the outer dimension of the seal 6, it is not necessary to enlarge the installation space of the seal 6.
[0031]
Hereinafter, application examples and other embodiments of the present invention will be described.
[0032]
(1) The outer lip 13 of the seal 6 is not contacted in a relatively large bent state as in the above-described embodiment, for example, in a lightly bent state or in a light touched state without bending. be able to. Furthermore, as shown in FIG. 4, the outer lip 13 of the seal 6 can be made non-contact with the annular step portion 4c on the base side of the trunnion 4a. In this case, although the outer lip 13 is not in contact, the minute gap 15 between the metal ring 10 of the seal 6 and the annular stepped portion 4c of the trunnion 4a can be almost closed with the outer lip 13, so muddy water, etc. Can be prevented.
[0033]
(2) In the above embodiment, an example in which the annular step portion 4c is provided in the region from the outer periphery of the root side shoulder portion 4b of the trunnion 4a is described, but the present invention is provided even when this annular step portion 4c is not provided. Can be applied. As shown in FIG. 5, when the annular step portion 4c is not provided, the outer end surface of the metal ring 10 is opposed to the region 4d near the outer periphery of the concave curved surface of the shoulder portion 4b with a minute gap 15 therebetween. The minute gap 15 may be closed with the outer lip 13.
[0034]
(3) The cross joint 1 is used for a drive shaft of an automobile or a power transmission path in an automobile steering mechanism, but can be used in a place where water resistance is required.
[0035]
【The invention's effect】
In the cross joint of the present invention, it is not necessary to form a circumferential groove in the trunnion as in the conventional example in order to improve the sealing performance of the roller bearing by the seal. Therefore, it is possible to improve the sealing performance of the roller bearing while suppressing an increase in cost as in the conventional example.
[Brief description of the drawings]
1 is a perspective view of a cross joint according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of a roller bearing shown in FIG. 1. FIG. 3 is an enlarged view of the seal of FIG. FIG. 5 is a diagram corresponding to FIG. 3 in another embodiment, FIG. 5 is a diagram corresponding to FIG. 3 in still another embodiment of the present invention, and FIG. 6 is a diagram corresponding to FIG. Explanation】
4 cross shaft 4a cross shaft trunnion 4b trunnion shoulder 4c trunnion annular step 5 roller bearing 6 seal 8 outer ring cup of roller bearing 10 metal ring 11 of seal 11 first inner lip 12 of seal second inner lip 13 of seal Outer lip of seal 15 Minute gap

Claims (2)

A cross shaft joint having a cross shaft including four trunnions and four roller bearings mounted on each trunnion,
Each of the roller bearings includes an outer ring cup, a plurality of rollers arranged on the inner periphery of the outer ring cup and interposed between the inner peripheral surface of the outer ring cup and the outer periphery of the trunnion, and the outer ring cup. A seal that is attached to the opening side end and seals the annular space between the trunnion outer peripheral surface and the outer ring cup;
The seal includes a metal ring attached to the inner periphery of the opening of the outer ring cup, an inner lip attached to the inner end of the metal ring, and an outer lip attached to the outer end of the metal ring. And
The inner lip contacts an annular curved surface portion that connects the trunnion and the cross shaft main body, and an outer end portion of the metal ring faces a trunnion side end surface of the cross shaft main body with a minute gap therebetween, and The outer lip is a cross joint that closes the minute gap. The cross joint according to claim 1,
The outer shaft lip is in a state of being bent so as to open outward in the radial direction, and is in contact with the trunnion side end surface of the shaft body to close the minute gap.

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