JPH08114220A - Bearing device for steering - Google Patents

Abstract

PURPOSE: To provide a bearing device for steering which absorbs angle displacement generated in a steering gear side shaft in steering operation and has stability, durability, and foreign matter resistance of a frictional torque. CONSTITUTION: A bearing device is constituted from a bearing consisting of an outer bush 2 and an inner bush 3, a housing 5 for fixing the bearing, and a steering gear side shaft 4 for pivotally mounting. The outer bush has a self- aligning part 25 and a projecting streak part 26 in its outside and the inner bush is held in an enlarged-diameter cylindrical part in the inside face of the outer bush. The outer bush holding the inner bush is pressed in so as to be tiltably fixed in the housing in the self-aligning part, the steering gear side shaft is slidingly contacted with a ring lip part 22 with interference in the inside of the outer bush, and it is pivotally mounted on the inner bush internal circumferencial face by holding a prescribed bearing clearance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering bearing device for an automobile, and more particularly to a steering bearing device for supporting a steering gear side shaft.

[0002]

2. Description of the Related Art As shown in FIG. 6, a steering gear side shaft 4 in a steering apparatus for an automobile is arranged between a steering column shaft 6 and an intermediate shaft 7, and universal joints 81 and 82 connect the shafts 6 and 7, respectively. The intermediate shaft 7 is connected to a gear box (not shown) via a universal joint. The steering gear side shaft 4 is supported by a steering bearing device B fixed to the vehicle body side bracket 9. The bearing device B
Serves to prevent a large shake of the steering gear side shaft 4 and the intermediate shaft 7 and efficiently transmit the torque from the steering wheel to the steering gear. The bearing device is required to have an angle absorbing function, and further, the friction torque is required. Stability and durability are required. Further, since the bearing device is located on the engine room side, foreign matter resistance is also required.

[0003]

Conventionally, a ball bearing has been used as the bearing at this location. The ball bearing has an angle absorbing function and stability of friction torque, but has a durability related to foreign matter resistance. In addition, the bearing itself needs to be finished with high accuracy because the housing to which the ball bearing is fixed and the steering gear side shaft supported by the bearing need to be finished with high accuracy. In addition to the high cost, there is a problem that the processing cost and the assembly cost also increase. The present invention has been made in view of the above circumstances, and when both ends of the steering gear side shaft swing during steering operation and rotate by performing a so-called swinging motion, the bearing device is angularly displaced without applying an excessive load. It is an object of the present invention to obtain a steering bearing device that can absorb the load and smoothly support the load acting on the shaft, and that has stable friction torque, durability and foreign matter resistance.

[0004]

According to the present invention, the above object is composed of an outer bush 2 made of a rubber elastic body or an elastic synthetic resin, and an inner bush 3 inserted into an inner surface of the outer bush. A steering bearing device comprising a bearing (1), a housing (5) for press-fitting and fixing the bearing, and a steering gear side shaft (4) supported by the bearing, wherein the outer bush is on the inner surface side near one end of the inner surface. An annular lip portion 22 that protrudes radially inward and a diameter-expanding cylindrical portion 2 that is continuous with the annular lip portion 2
3 and the lip portion, which is provided with a locking ridge portion 24 projecting at a part or the whole circumference in the circumferential direction of the diameter-expanded cylindrical portion which is axially spaced by a predetermined distance, and is self-aligning on the outer surface side thereof. Part 2
5 and a plurality of protrusions 26 formed in the axial direction of the bush and over the entire circumference in the circumferential direction. The inner bush includes an annular lip portion and a locking protrusion portion on the inner surface of the outer bush. The outer bush holding the inner bush is press-fitted and fixed in the housing in a tiltable manner at the outer self-aligning portion on the outer surface side, and the shaft on the steering gear side is the outer shell. This is achieved by a steering bearing device, which is slidably contacting an annular lip portion on the inner surface of the bush with an interference, and is supported while maintaining a predetermined bearing gap with the inner peripheral surface of the inner bush.

In the steering bearing device having the above-mentioned structure, the self-aligning portion 2 on the outer surface of the outer bush 2 is provided.
Reference numeral 5 denotes a narrow cylindrical portion formed in the central portion of the outer surface and a taper portion that gradually decreases in diameter from the cylindrical portion toward the end of the bush. The outer bush 2 is formed on the inner surface of the housing in the cylindrical portion. It is also possible to adopt a configuration in which it is press-fitted and fixed, and the tapered portion is disposed inside the housing while maintaining a gap with the inner surface of the housing.

Further, in the steering bearing device having the above-mentioned structure, the self-aligning portion 25 on the outer surface of the outer bush 2 is a convex spherical surface portion, and the outer bush 2 is press-fitted and fixed to the inner surface of the housing at the top of the convex spherical surface portion. It is also possible to adopt a configuration in which the other spherical surface portions are arranged inside the housing while maintaining a gap with the inner surface of the housing.

In any of the above-mentioned constitutions, natural rubber or synthetic rubber is used as the rubber elastic body forming the outer bush, and the synthetic resin having elasticity is flexible and tough, and generally has a Shore hardness. Sa (D type)
40 to 60, impact resilience value (JIS-K6301) of 50 to 80, and rubber-like elastic behavior remains, for example, polyester / ether copolymer or polyurethane is used, inner bush Comprises a three-layer structure of a steel thin plate, a sintered alloy layer integrally bonded to the surface of the steel thin plate, and a synthetic resin layer impregnated and coated on the sintered alloy layer,
A winding bush having a cylindrical shape with the synthetic resin layer inside is used. Further, the inner diameter of the annular lip portion on the inner surface of the outer bush is an amount corresponding to the clearance (sliding gap) between the inner bush and the steering gear side shaft supported by the inner bush rather than the inner diameter of the inner bush, Specifically, it is formed to be small by 0.02 to 0.20 mm.

[0008]

In the steering bearing device of the present invention having the above-described structure, both ends of the shaft on the steering gear side are swung during steering operation due to the action of the self-aligning portion formed on the outer surface of the outer bush, so that a so-called swing motion is performed. When the bearing is rotated, the angular displacement can be absorbed without an excessive load acting on the bearing device, and the load acting on the shaft can be smoothly supported. Further, stable friction torque, durability and foreign matter resistance can be obtained. The shaft can be supported with flexibility.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings showing its embodiments. 1 to 3 show a first configuration of the present invention. In the figure, reference numeral 1 is a bearing, and the bearing 1 is composed of an outer bush 2 made of a rubber elastic body or a synthetic resin having elasticity, and an inner bush 3 inserted and fixed to the inner surface of the outer bush 2.

On the inner surface 21 side of the outer bush 2, an annular lip portion 22 that projects radially inward near one end of the inner surface and a diameter-expanding cylindrical portion 23 that is continuous with the annular lip portion 23 are formed.
And a locking projection 24 having a diameter larger than the inner diameter of the inner bush 3 and projecting over the entire circumference in the circumferential direction of the diameter-expanded cylindrical portion axially spaced from the lip portion by a predetermined distance. And a self-centering portion 25 comprising a narrow cylindrical portion formed on the outer surface side in the central portion of the outer surface and a taper portion that gradually reduces in diameter from the cylindrical portion toward the end of the outer bush. It has a plurality of ridges 26 formed in the axial direction of the bush and over the entire circumference in the circumferential direction.

The inner bush 3 has a three-layer structure of a steel thin plate, a sintered alloy layer integrally bonded to the surface of the steel thin plate, and a synthetic resin layer impregnated and coated on the sintered alloy layer. It consists of a winding bush that is wound in a cylindrical shape with the resin layer inside. In FIG. 1, reference numeral 31 is a butt portion of the winding bush.

The inner bush 3 is inserted and held in a radially expanded cylindrical portion 23 between the annular lip portion 22 and the locking projection portion 24 on the inner surface of the outer bush 2 to form the bearing 1. In this structure, the diameter of the annular lip portion 22 on the inner surface of the outer bush 2 is larger than the inner diameter of the inner bush 3 by the inner bush 3 and the inner bush 3.
The amount corresponding to the clearance (sliding gap) from the shaft 4 on the steering gear side supported by
It is made smaller by ~ 0.20mm. Further, the inner bush 3 has an annular lip portion 22 on the inner surface of the outer bush 2.
The inner bush 3 is prevented from slipping out of the outer bush 2 by being inserted and held in the expanded diameter cylindrical portion 23 between the locking projection 24 and the locking projection 24.

In the bearing 1 constructed as described above, the outer bush 2 is press-fitted and fixed to the inner surface of the housing 5 at the cylindrical portion of the self-aligning portion 25 formed on the outer surface of the outer bush 2, and the self-aligning portion 25 The tapered portion is arranged in the housing 5 with a gap maintained between the tapered portion and the housing 5. Since the plurality of protrusions 26 formed over the entire circumference of the outer bush 2 in the axial direction are closely pressed and fixed to the inner surface of the housing 5, the influence of the press-fitting on the inner diameter of the inner bush 3 is minimized. To be prevented. Further, since the outer bush 2 is tightly fixed to the inner surface of the housing 5, no slip occurs between the inner surface of the housing 5 and the outer bush 2.

The housing 5 to which the bearing 1 is press-fitted and fixed has a flange-shaped mounting portion, and is fixed to the vehicle body side bracket at the mounting portion. The inner bush 3 of the bearing 1 has a shaft 4 on the steering gear side.
Is inserted to form a bearing device. When inserting the steering gear side shaft 4 into the bearing 1, even if there is a misalignment of the shaft center due to manufacturing tolerances or so-called misalignment, the self-aligning part 25 formed on the outer surface of the outer bush 2 and a plurality of self-aligning parts are formed. The misalignment is absorbed by the action of the elastic deformation of the ridge portion 26.

The steering gear side shaft 4 is in sliding contact with the annular lip portion 22 on the inner surface of the outer bush 2 with an interference, and is elastically supported by the lip portion 22. Therefore, when no load is applied to the steering gear side shaft 4 at the time of idling, the shaft 4 is supported by the annular lip portion 22 on the inner surface of the outer bush 2,
Since the vibration acting on the shaft 4 is absorbed by the elastic deformation of the lip portion 22, the vibration is not transmitted to the steering column shaft side. Further, although the bearing device is located in the engine room side and arranged in a place where foreign matter easily enters, the lip portion can prevent foreign matter from entering the inner bush from the engine room side and maintain durability. be able to.

Further, the steering gear side shaft 4
Both ends of the universal joint 8 are
The bearing device B, which is connected to the steering column shaft 6 and the intermediate shaft 7 by 1, 82 and supports the shaft 4, is incorporated in the steering device. In the steering bearing device configured as described above, when both ends of the steering gear side shaft 4 swing during steering operation (when the steering wheel rotates) and rotate in a so-called oscillating motion, they are formed on the outer surface of the outer bush 2. The angular displacement is absorbed by the action of the self-aligning portion 25 thus set, and the load acting on the shaft 4 is smoothly supported. FIG. 8 is a cross-sectional view of the steering bearing device of the present invention at the time of automatic alignment.
An example is shown in which the axis line of (1) and the axis line of the steering gear side shaft 4 are extremely deviated, and the angular displacement is absorbed even in such a case.

FIG. 4 shows a second configuration of the present invention. In this second structure, the self-aligning portion 25 on the outer surface of the outer bush 2 in the first structure is a convex spherical surface, and the other structures are the same as the first structure. The outer bush 2 is press-fitted and fixed to the inner surface of the housing 5 at the top of the self-aligning portion 25 on the outer surface of the outer bush 2, and the other spherical surface portions are arranged in the housing 5 with a gap maintained between the outer spherical surface and the housing 5. Also in this mode, when both ends of the steering gear side shaft 4 swing during the steering operation (when the steering wheel rotates) and rotate by performing a so-called swinging motion, the self-aligning portion 25 formed on the outer surface of the outer bush 2 is rotated. The angular displacement is absorbed by the action, and the load acting on the shaft 4 is smoothly supported. Further, the same effect can be obtained even if the self-aligning portion 25 on the outer surface of the outer bush 2 is a convex curved surface having a different curvature in the axial direction and the curvature in the circumferential direction of the outer bush 2.

FIG. 5 shows another embodiment of the present invention and is a view showing a lip portion on the inner surface of the outer bush 2. In this embodiment, the annular lip portion 22 on the inner surface of the outer bush 2 in the first construction is divided into a plurality of lip portions 22a in the circumferential direction, and the other constructions are the same as the first construction. Is. By adopting such a configuration, it is possible to reduce the influence of the tightening margin of the lip portion 22a on the friction torque on the steering gear side shaft 4 slidably supported by the lip portion 22a. This embodiment can be applied to the above-mentioned second structure and has the same effect.

In the above-mentioned first and second configurations, a plurality of ridge portions 2 formed on the outer surface of the outer bush 2
6 has been illustrated as having a triangular cross section, the ridge 26 has a cross section of other square shape,
The shape may be semicircular. Further, a locking protrusion 24 having a diameter larger than the inner diameter of the inner bush 3 and smaller than the outer diameter is formed on the entire circumference of the radially expanded cylindrical portion 23 which is axially spaced from the annular lip portion 22 of the outer bush 2 by a predetermined distance. Although the above embodiment has been illustrated, the same effect can be obtained even if a plurality of the locking projections 24 are formed on the expanded diameter cylindrical portion 23 in a part of the circumferential direction thereof.

[0020]

According to the steering bearing device of the present invention having the above-mentioned structure, both ends of the shaft on the steering gear side are prevented from operating at the time of steering operation (when the steering wheel is rotated) by the action of the self-aligning portion formed on the outer surface of the outer bush. When rotating by swinging, so-called swinging motion, the angular displacement is absorbed without an excessive load acting on the bearing device,
The load acting on the shaft can be smoothly supported, and the shaft can be supported with stable friction torque, durability and foreign matter resistance.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first configuration of a steering bearing device of the present invention.

FIG. 2 is a sectional view taken along the line EE of FIG.

FIG. 3 is an enlarged view of part A in FIG.

FIG. 4 is a cross-sectional view showing a second configuration of the steering bearing device of the present invention.

FIG. 5 is another embodiment of the present invention.

FIG. 6 is a view showing a connected state of a steering gear side shaft and an assembled state of a steering bearing device in the steering device.

FIG. 7 is a view showing how the steering bearing device of the present invention is attached to a vehicle body side bracket.

FIG. 8 is a cross-sectional view of the steering bearing device of the present invention during automatic alignment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bearing 2 Outer bush 22 Annular lip part 23 Expanding diameter cylindrical part 24 Locking protrusion part 25 Self-aligning part 26 Convex part 3 Inner bush 4 Steering gear side shaft 5 Housing

Claims (4)

[Claims] 1. A bearing (1) comprising an outer bush (2) made of a rubber elastic body or an elastic synthetic resin and an inner bush (3) inserted into the inner surface of the outer bush, and the bearing is press-fitted. A bearing device for steering comprising a housing (5) for fixing and a steering gear side shaft (4) supported by the bearing,
The outer bush has, on its inner surface side, an annular lip portion (22) projecting radially inward in the vicinity of one end portion of the inner surface, a radially expanded cylindrical portion (23) continuous with the annular lip portion, the lip portion and the shaft. A cylindrical protrusion (24) projecting to a part or the whole circumference in the circumferential direction of the expanded diameter cylindrical portion that is spaced at a predetermined interval in the direction, and an automatic centering portion (25) on the outer surface side. The inner bush is provided with a plurality of ridges (26) formed in the axial direction of the bush and over the entire circumference in the circumferential direction, and the inner bush has an annular lip portion and a locking ridge portion on the inner surface of the outer bush. The outer bush holding the inner bush is press-fitted and fixed in the housing so as to be tiltable in the self-aligning portion on the outer surface side, and the shaft on the steering gear side is the outer shell. In the bush The annular lip in sliding contact with the interference, and the steering bearing apparatus characterized by being supported by retaining a predetermined bearing clearance with an inner bushing inner circumferential surface. 2. A self-aligning portion (25) on the outer surface of the outer bush (2) has a narrow cylindrical portion formed in the central portion of the outer surface and a diameter gradually decreasing from the cylindrical portion toward the end of the bush. The outer bush (2) consisting of a taper part
The steering bearing device according to claim 1, wherein the cylindrical portion is press-fitted and fixed to the inner surface of the housing, and the tapered portion is arranged in the housing with a gap maintained between the inner surface of the housing and the tapered portion. 3. A self-aligning portion (25) on the outer surface of the outer bush (2) is formed of a convex spherical surface portion, and the outer bush (2) is press-fitted and fixed to the inner surface of the housing at the top of the convex spherical surface portion. The steering bearing device according to claim 1, wherein the portion is disposed in the housing with a gap maintained between the inner surface and the inner surface of the housing. 4. The inner bush (3) has a three-layer structure of a steel thin plate, a sintered alloy layer integrally bonded to the surface of the steel thin plate, and a synthetic resin layer impregnated and coated on the sintered alloy layer. ,
The steering bearing device according to any one of claims 1 to 3, comprising a winding bush wound in a cylindrical shape with the synthetic resin layer inside.