JP2000320543A - Sliding bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress generation of noise, following the rotation of a shaft and sufficiently low suppress even friction torque when the shaft is rotated, by sufficiently ensuring lubricating function between the internal peripheral surface of a bearing main unit and the external peripheral surface of the shaft. SOLUTION: A steering shaft 2 is supported rotatably in slide contact on a slide abutting internal peripheral surface 20 of a bearing main unit 11, press fit fixed in a steering column 3 consisting of a synthetic resin or the like, and many fine recessed parts are formed in the slide abutting internal peripheral surface 20 of the bearing main unit 11. A lubricant of, for instance, grease or the like can be accumulated in many of these fine recessed parts, also this fine recessed part is, for instance, 'grain' used for surface finishing by resin molding, and surface roughness is preferable 1.6 to 12.5 μmRa in a JIS standard.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to sufficiently secure a lubricating function between an inner peripheral surface of a bearing body and an outer peripheral surface of a shaft to sufficiently reduce vibration and hitting sound such as "rattle" of the shaft. The present invention relates to a sliding bearing that absorbs frictional force and suppresses friction torque during rotation of a shaft to a sufficiently low level.

[0002]

2. Description of the Related Art For example, in a steering column for an automobile, since a steering shaft has a low rotation and a transmission torque thereof is low, a requirement concerning a rotation condition is not so high, but mainly a vibration acting on the steering shaft is absorbed. Due to the necessity to perform the rotation, it is common to use a sliding bearing instead of a ball bearing as a bearing for rotatably supporting the steering shaft.

[0003] As a sliding bearing used for such a steering column, for example, Japanese Utility Model Publication No. 1-28338 discloses a cylindrical bearing body made of a synthetic resin which is press-fitted and fixed singly on the inner peripheral surface of the steering column. In addition, a steering shaft is rotatably slidably supported on the inner peripheral surface of the cylindrical bearing body.

In Japanese Utility Model Publication No. 55-28898 and Japanese Utility Model Publication No. 58-54292, a cylindrical bearing body made of synthetic resin or the like is press-fitted and fixed to the inner peripheral surface of a steering column. In the groove provided on the outer peripheral surface of
A leaf spring or an O-ring is elastically interposed, and a steering shaft is rotatably slidably supported on the inner peripheral surface of the cylindrical bearing main body.

[0005] The sliding bearing constructed as described above exhibits a vibration absorbing function of absorbing vibration and hitting sound acting on the steering shaft, such as "rattle", and a low friction torque during rotation of the steering shaft. It has a friction torque function.

[0006]

In the sliding bearings disclosed in Japanese Utility Model Publication No. 1-23838, Japanese Utility Model Publication No. 55-28898 and Japanese Utility Model Publication No. 58-54292, the cylindrical bearing body is Although the inner peripheral surface is in sliding contact with the outer peripheral surface of the steering shaft, the inner peripheral surface of the bearing body is finished smooth (flat). Therefore, between the inner peripheral surface of the bearing body and the outer peripheral surface of the steering shaft, there is a possibility that a lubricant such as grease may cause an oil film to break.

[0007] As described above, if the lubrication state is not very good, the lubrication function of the sliding bearing is deteriorated, and abnormal noise may be generated. In addition, the low friction torque function is also deteriorated, and the friction torque is increased. May be done.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and has a sufficient lubricating function between an inner peripheral surface of a bearing body and an outer peripheral surface of a shaft to reduce abnormal noise. It is an object of the present invention to provide a sliding bearing in which generation is suppressed and friction torque during rotation of the shaft is sufficiently suppressed.

[0009]

In order to achieve the above-mentioned object, a sliding bearing according to the present invention is arranged such that a shaft is rotatable on a sliding inner peripheral surface of a bearing body which is made of an elastic body and is press-fitted and fixed in a housing. In a sliding bearing which is slidably supported, a large number of minute recesses are formed on an inner peripheral surface of the sliding body of the bearing body.

As described above, according to the present invention, since a large number of minute recesses are formed on the inner circumferential surface of the bearing body in sliding contact, a lubricant such as grease is stored in these many minute recesses. be able to. Therefore, when the shaft rotates, grease or the like spreads between the inner peripheral surface of the bearing body and the outer peripheral surface of the shaft, and it is possible to continuously and sufficiently ensure the lubrication performance therebetween. Therefore, it is possible to suppress the generation of abnormal noise due to the rotation of the shaft, and to sufficiently reduce the friction torque during the rotation of the shaft.

The above-mentioned minute recesses are, for example, "textures" used for surface finishing by resin molding. The surface roughness is preferably 1.6 to 12.5 μm Ra according to JIS.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sliding bearing according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a state in which a vehicle steering device is mounted, and FIG. 2 is a sectional view when a slide bearing according to an embodiment of the present invention is used as a steering column bearing. 3 is an arrow view as viewed from the direction of arrow A in FIG. 2, and the lower half is a cross-sectional view along line III-III in FIG. 2.

As shown in FIG. 1, a steering shaft 2 having a steering wheel 5 at an upper portion is rotatably supported by a sliding bearing 1 press-fitted into an inner surface of an upper end of a steering column 3 (housing). The upper part is fixed to the vehicle body part 6 by the column bracket 4 and the lower end is the steering gear box part 7.
It is fixed to.

As shown in FIGS. 2 and 3, the sliding bearing 1 has a bearing body 11 made of a synthetic resin and an elastic ring 12 such as an O-ring fitted in a groove 11A provided on the outer peripheral surface of the bearing body 11. Consists of

The bearing body 11 is provided with a slit 11B which is broadly split from the outer surface to the inner surface in the axial direction.
It can be used commonly for steering shafts having a diameter of about 1 mm.

The outer diameter of the bearing body 11 is the same as that of the elastic ring 1.
In a natural state in which the steering column 3 is not fitted and the steering column 3 is not fitted, the inner diameter of the bearing fitting surface of the steering column 3 is equal to or larger than the inner diameter. The inner diameter of the bearing 11 is determined so that the thickness of the bearing 11 is equal to or less than half the value obtained by subtracting the outer diameter of the steering shaft from the inner diameter of the bearing fitting surface of the steering column.

When the elastic ring 12 is fitted to the bearing body 11A, the elastic ring 12 has a line diameter and an inner and outer diameter dimension which make the bearing clearance with the steering shaft 2 zero with respect to the concave groove 11A. Further, it has a wire diameter protruding from the outer peripheral surface of the bearing body 11.

When such a sliding bearing 1 is mounted between the steering column 3 and the steering shaft 2, the elastic ring 12 is press-fitted into the steering column 3, and
A minute gap is created between the steering column bearing fitting surface and the bearing main body 11, and the elastic ring 12 elastically supports the bearing main body 11 with respect to the steering column 3. Further, by tightening the elastic ring 12, the steering shaft 2
And the bearing clearance between them becomes zero.

When such a sliding bearing 1 is mounted on the steering column 3, only the elastic ring 12 is press-fitted, and the bearing body 11 has a clearance fit, so that the assembling work is easy.

Further, in the present embodiment, the bearing body 11
A large number of minute concave portions are formed on the inner peripheral surface 20 of the sliding contact.
The minute recesses are specifically “textures” used for surface finishing by resin molding, and the surface roughness is preferably 1.6 to 12.5 μmRa according to JIS. However, the shape and size of the minute concave portion may be various.

As described above, the sliding inner peripheral surface 2 of the bearing body 11
Since a large number of minute recesses are formed in the small number 0, a lubricant such as grease can be stored in these many minute recesses. Therefore, when the steering shaft 2 rotates, grease or the like spreads between the inner peripheral surface 20 of the bearing body 11 and the outer peripheral surface of the steering shaft 2, and the lubricating performance therebetween can be continuously and sufficiently ensured. .

Therefore, it is possible to suppress the generation of abnormal noise due to the rotation of the steering shaft 2 and to sufficiently reduce the friction torque when the steering shaft 2 rotates.

The present invention is not limited to the above-described embodiment, but can be variously modified.

For example, in the above-described embodiment, the sliding bearing according to the present invention is applied to a bearing for a steering column. However, the present invention is not limited to the buffering bearing for the steering column, but is applied to other vehicle parts. Alternatively, the present invention may be applied to a device other than a vehicle.

The shape, structure, dimensions, etc. of the sliding bearing are as follows:
The present invention is not limited to the above embodiment, and can be variously modified. For example, in the above embodiment, the bearing main body 11 is not press-fitted into the steering column 3, but may be configured to be press-fitted. The elastic ring 12 and the like need not be particularly provided.

Further, the bearing body may have a double structure. For example, an outer bush press-fitted into a housing such as a steering column and a shaft such as a steering shaft inserted into the outer bush and rotating a steering shaft. It may be constituted by an inner bush that slides freely and supports it.

[0028]

As described above, according to the present invention,
Since a large number of minute concave portions are formed on the sliding contact inner peripheral surface of the bearing body, a lubricant such as grease can be stored in these many minute concave portions. Therefore, when the shaft rotates, grease or the like spreads between the inner peripheral surface of the bearing body and the outer peripheral surface of the shaft, and it is possible to continuously and sufficiently ensure the lubrication performance therebetween. Therefore, it is possible to suppress the generation of abnormal noise due to the rotation of the shaft and, at the same time, to sufficiently reduce the friction torque during the rotation of the shaft.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state in which a vehicle steering device is mounted.

FIG. 2 is a sectional view when the slide bearing according to the embodiment of the present invention is used as a steering column bearing.

3 is an arrow view as viewed from the direction of arrow A in FIG. 2, and a lower half is a cross-sectional view along line III-III in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sliding bearing 2 Steering column (housing) 3 Steering shaft (shaft) 4 Column bracket 5 Steering wheel 6 Body part 7 Steering gear box part 11 Bearing body 11A Groove 11B Slit 12 Elastic ring 20 Sliding inner peripheral surface

Claims (1)

[Claims] 1. A sliding bearing for supporting a shaft by slidingly contacting a shaft on a sliding inner peripheral surface of a bearing body made of an elastic body and press-fitted and fixed in a housing; A sliding bearing having a large number of minute recesses.