JP5326290B2 - Radial roller bearing device - Google Patents

Description

  The present invention relates to a radial roller bearing and a radial roller bearing device in a bearing device for a steering column used in a steering device of an automobile, for example.

  In general, in an automobile steering apparatus in which a steering shaft is connected between a steering wheel and a universal joint, a steering column supported on the vehicle body side is used to transmit the movement of the steering wheel operated by the driver to the steering mechanism. And a steering shaft inserted inside the steering column, and a steering column bearing device for supporting the steering shaft on the steering column.

The steering column bearing device includes an annular case fitted to the inner peripheral surface of the steering column, and a roller bearing that is housed in the annular case and supports the steering shaft on the steering column.
This roller bearing includes an outer ring, a plurality of rollers, and a cage that holds these rollers.
The annular case is made of an elastic material such as rubber, and is composed of a cylindrical main body provided around the outer ring and cylindrical flanges formed radially inward from both ends of the cylindrical main body. An annular recess for the annular bearing that opens is formed.
The annular case is press-fitted into the inner peripheral surface of the stirling column in a state where the roller bearing is housed in the annular recess.
The needle-shaped rollers are always pressed against the steering shaft through the outer ring by the compression elastic preloading action of an annular case made of elastic material such as rubber, and the radial shading in the steering column of the steering shaft is prevented. This improves the operability of the steering wheel. (See Patent Document 1).
JP 2006-111082 A (3rd page, FIG. 5)

In the case of the conventional steering column bearing device described above, the needle roller is always pressed against the steering shaft and the outer ring by the compression elastic preload action of the annular case made of an elastic material such as rubber. If the shape is bad, the rotational tone of the needle rollers is deteriorated, which is directly transmitted as a steering feeling of the steering wheel, and the steering feeling is deteriorated.
Accordingly, an object of the present invention is to provide a radial roller bearing in which the outer ring raceway shape is improved to eliminate the uneven rotation of the needle rollers and no abnormal noise is generated.

A radial roller bearing device according to the present invention includes a split outer ring formed into a cylindrical shape by bending a steel plate, a plurality of rollers arranged to roll inside the outer ring and arranged at predetermined intervals in the circumferential direction, A radial roller bearing having a retainer for holding the rollers, and a radial roller bearing through which a shaft is inserted, and an annular bearing housing case that is externally fitted to the outer periphery of the outer ring and is made of an elastic material. In the bearing device, the width of the projecting portion protruding inward generated during the processing of the outer ring in a circumferential direction of the outer ring is such that at least two adjacent rollers are mounted, and the compression elasticity of the bearing storage case The inner ring surface of the outer ring that is pressurized in a direction to stick to the outer diameter surface of the cage by preload has the following gap between the outer diameter surface of the cage,
(Gap) =
{(Diameter of the shaft) + (diameter of the roller) × 2- (outer diameter of the cage)} / 2> 0
Monodea is, the steel plate of the radial roller bearing of the description, a plurality of the steel strip is, has been connected by the connecting portion, the outer ring of the radial roller bearing of the description, after the steel sheet is bent The said convex part of the radial roller bearing of the said description is a convex part generate | occur | produced in the area | region connected by the said connection part.

In the radial roller bearing according to the present invention, at least two of the rollers adjacent to each other have a width in the outer ring circumferential direction of the projecting portion protruding inward that is generated during processing of the one-piece outer ring formed in a cylindrical shape. Therefore, if one of the adjacent rollers starts to climb up the convex part before one roller finishes over the convex part, the height at which the roller rides on the convex part is substantially reduced. There is an effect that the feeling of overcoming the convex portion is reduced, the rotation unevenness of the roller is reduced, and the occurrence of abnormal noise is also reduced.
Further, in the radial roller bearing device according to the present invention, since the annular bearing storage case made of an elastic material is fitted on the outer periphery of the outer ring of the radial bearing described above, the radial roller bearing is stored. When the bearing storage case is press-fitted into the inner peripheral surface of the steering column in the state and the radial roller bearing device is used as a bearing device for a steering column, for example, the outer ring is caused by the compression elastic preload action of the bearing storage case made of an elastic material. Since the roller is always pressed against the steering shaft as a shaft through the roller and there is little uneven rotation of the roller, a good steering feeling can be obtained.
Further, in the radial roller bearing device, since the outer diameter dimension of the cage of the radial bearing described above is set so that a gap is formed between the outer ring and the outer diameter surface of the cage, the inner peripheral surface of the outer ring There is no sliding resistance of the outer diameter surface of the cage with respect to the roller, and the cage rotates smoothly along with the roller revolution of the roller, thereby suppressing the occurrence of a feeling of backlash in the circumferential direction.

Embodiment 1 FIG.
1 is a cross-sectional view showing a steering column bearing device according to Embodiment 1 of the present invention, FIG. 2 is a front view of an outer ring of the steering column bearing device, and FIG. 3 is a manufacturing process of the outer ring of the steering column bearing device. FIG. 4 is a sectional view showing the relationship with the outer ring portion of the steering column bearing device.
In the figure, the steering device is a shaft box 1 that is a cylindrical steering column, a shaft 2 that is a steering shaft inserted inside the shaft box 1, and a steering column bearing device that supports the shaft 2 on the shaft box 1. 3.

The steering column bearing device 3 includes an annular bearing storage case 4 fitted to the inner peripheral surface of the axle box 1 and a radial needle shape as a radial bearing which is stored in the bearing storage case 4 and supports the shaft 2. A roller bearing 5;
The annular bearing storage case 4 is formed of a resilient cylindrical cylindrical material such as rubber or resin, is cylindrical in the axial direction provided around the outer ring 6, and has a radial thickness along the axial direction. An annular bearing housing comprising an equally formed cylindrical main body portion 4a and an annular flange portion 4b extending radially inward from both axial ends of the cylindrical main body portion 4a. An annular recess 4c is formed.
A radial needle roller bearing 5 includes a single outer ring 6 formed in a thin cylindrical shape from a steel plate, and needle rollers 7 as a plurality of rollers made of bearing steel, which are incorporated on the inner peripheral surface side of the outer ring 6. It comprises a retainer 8 made of a steel plate or a resin to be held. Reference numeral 6 a denotes a slit in the split portion of the outer ring 6. As shown in FIG. 2, the slit 6 a is skewed with respect to the width direction of the outer ring 6 in order to reduce the adverse effect of giving a radial play to the needle rollers 7 when a step occurs in the split part. Is formed.
In the steering column bearing, the roller diameter is usually about 1.8 to 3.5 mm, and the number of rollers is about 10 to 40.
Then, after the bearing housing case 4 made of an elastic material in which the radial needle roller bearing 5 is housed in the shaft box 1 is press-fitted, the needle is inserted through the outer ring 6 by the compression elastic preloading action of the rubber in the bearing housing case 4. The needle roller 7 is always pressed against the shaft 1, and the clearance between the needle roller 7 and the shaft 1 becomes 0 (hereinafter, “radial clearance is 0”), so that the radial backlash of the needle roller 7 is reduced. It can be suppressed.

Next, a method for manufacturing the outer ring 6 of the radial needle roller bearing 5 used in the first embodiment will be described.
First, as shown in FIG. 3, the strips 11 are arranged at intervals so as to obtain, for example, four outer rings 6, so that one sheet 10 is obtained by a press machine in a shape in which the connecting portion 12 remains in the center. Punch out. In a steering column bearing, the plate thickness is usually about 0.4 to 1.0 mm.
Next, each strip-shaped steel plate 11 is bent into a cylindrical shape with a forming machine so that the mating surfaces of the split portions are aligned with each other.
Finally, the connecting portion 12 is cut off, the strip-shaped steel plates 11 bent into a cylindrical shape are separated from each other to form the outer ring 6, and the outer ring 6 is subjected to hardening heat treatment to complete the manufacture.

As described above, when the outer ring 6 is manufactured, when the strip-shaped steel plates 11 are bent into a cylindrical shape so that the mating surfaces of the split portions are aligned with each other, the central portion of each strip-shaped steel plate 11 is connected by the connecting portion 12. Therefore, the vicinity of both sides of the connecting portion 12 of each strip steel plate 11 is constrained and deformed. Therefore, as shown in FIG. A convex portion that protrudes inward is formed, that is, as shown in FIG. 4, a convex portion 14 that protrudes toward the center is formed on the inner diameter surface of the outer ring 6. The height of the convex portion 14 formed on the inner diameter surface of the outer ring 6 is usually several tens of μm in a steering column bearing having an outer ring inner diameter of about 20 to 60 mm. Although the two convex portions 14 are easily formed near both sides of the connecting portion 12, the number and size may differ depending on conditions such as plate thickness, plate material, outer ring diameter, and connecting portion shape.
Therefore, when the outer ring 6 having the convex portion 14 on the inner diameter surface is used for the radial needle roller bearing 5, the needle roller 7 rides on the convex portion 14 of the outer ring 6 when attention is paid to one of the convex portions 14. The rotational tone of the needle roller 7 is deteriorated.
In addition, the outer ring circumferential width of the convex portion 14 means from one end in the circumferential direction to the other end of the convex portion 14 projecting to the inner diameter side from the virtual circle when the inner diameter of the outer ring 6 is a perfect circle.

In this way, when one needle roller 7 rides on the convex portion 14 formed on the inner diameter surface of the outer ring 6 from one side of the convex portion 14 to the other side, a feeling of overcoming the convex portion 14 of the needle roller 7 occurs. To do.
However, when the next adjacent needle roller 7 starts to rise up the convex portion 14 before the needle roller 7 finishes over the convex portion 14, the height at which the two needle rollers 7 ride on the convex portion 14 is substantially high. Thus, the resistance when the roller rides up is reduced, so that the feeling of getting over the convex portion 14 of the needle roller 7 is reduced.
In this case, if the height of the convex portion 14 is constant and the width of the convex portion 14 in the outer ring circumferential direction is constant, the needle pitch can be changed by changing the roller pitch (distance between the roller centers) of the two needle rollers 7. It can be set so that the next adjacent needle roller 7 starts to rise up the convex part 14 before the roller 7 finishes over the convex part 14.
Such a bearing can be realized by adjusting the shape of the projection 14 according to the shape of the connecting portion 12 of the outer ring 6, the cutting method, the plate thickness and material of the outer ring 6, or changing the roller pitch.
However, since the number of rollers that can be applied to a predetermined size of the outer ring 6 is limited, when the roller pitch cannot be arbitrarily changed, the width of the convex portion 14 is changed.

In the first embodiment, in order to compare the roller pitch with the width of the convex portion 14 in the circumferential direction of the outer ring, the roller pitch is set to the roller pitch angle α (the center of the two needle rollers 7 with respect to the center of the outer ring 6). The width of the convex portion 14 in the outer ring circumferential direction is defined as the convex portion allowable angle β (the angle formed by the line segment connecting both sides of the convex portion 14 with respect to the center of the outer ring 6). ), For example, if the number of rollers is 8, as shown in FIG. 4, the roller pitch angle α is 360 ° / 8 ° and 45 °, and the convex portion allowable angle β1 of the convex portion 14 is 50 ° which is 45 ° or more. Thus, when the next adjacent needle roller 7 starts to climb up the convex portion 14 before the needle roller 7 finishes over the convex portion 14, the height at which the two needle rollers 7 ride on the convex portion 14. Is substantially reduced, the feeling of overcoming the convex portion 14 of the needle roller 7 is reduced, and the rotation unevenness of the needle roller 7 is reduced. As a result, the occurrence of abnormal noise is reduced.
If the convex portion allowable angle β2 of the convex portion 14 is set to 30 °, the next adjacent needle roller 7 until one needle roller 7 finishes running from one side of the convex portion 14 to the other side. Therefore, a feeling of overcoming the convex portion 14 of the needle roller 7 occurs.
Furthermore, when the roller pitch angle α is 45 °, the height at which the two needle rollers 7 ride on the convex portion 14 is substantially halved if the convex portion allowable angle β is set to 90 °. The feeling of getting over the convex portion 14 is halved, the rotation of the needle roller 7 is reduced, the generation of noise is reduced, and when the radial needle roller bearing 5 is used as a steering column bearing device, good steering is achieved. Feeling is obtained.

The above explanation is for the case where the number of rollers is 8 as shown in FIG. 4 as shown in FIG. 4, but the actual number of mass production type rollers is 13, 23, 21 and other types. In this case, the roller pitch angle α is 27.7 °, 15 °, and 17 °, respectively, and by setting the allowable convex portion angle β of the outer ring 6 to 30 °, the needle roller 7 causes the convex portion 14 to move. The next adjacent needle roller 7 starts to climb up the convex portion 14 before the ride over, and in this case, the height at which the two needle rollers 7 ride on the convex portion 14 is substantially reduced. The feeling of getting over the convex portion 14 is greatly reduced, the rotation of the needle rollers 7 is reduced, and the occurrence of abnormal noise is also reduced.
That is, with respect to all of the plurality of convex portions 14 formed on the outer ring 6, the next adjacent needle roller 7 rides before one needle roller 7 rides from one side to the other side. Good.

Embodiment 2. FIG.
FIG. 5 is a cross-sectional view showing a steering column bearing device according to Embodiment 2 of the present invention.
In the first embodiment, after the bearing storage case 4 made of an elastic material in which the radial needle roller bearing 5 is stored in the axle box 1 is press-fitted, the outer ring is caused by the compression elastic preloading action of the elastic material of the bearing storage case 4. 6, the needle roller 7 is always pressed against the shaft 1 and the radial gap becomes zero, so that the radial play of the needle roller 7 is suppressed.
The outer ring 6 has a single-piece shape formed by bending a steel plate, which is an elastic material, and always tries to stick to the outer diameter surface of the cage 8 by the compression elastic preloading action of the rubber of the bearing housing case 4. If the outer diameter dimension of the cage 8 is not set appropriately, the guide gap with the inner diameter surface of the outer ring 6 is eliminated, sliding resistance is generated, and the rotation condition is affected.

In addition, when sliding resistance occurs, the needle roller 7 smoothly revolves within the window of the cage 8 when the shaft rotates, but this moment feels because the momentary torque that hits the window of the cage 8 increases. The circumferential direction appears as a round, which also affects the rotation tone.
Therefore, in the second embodiment, the radial clearance is always kept at 0 by the compression elastic preloading action of the elastic body of the bearing housing case 4, so that the inner diameter A of the outer ring 6 = (shaft diameter B + roller diameter × 2). It can be considered that the guide gap between the inner diameter A of the outer ring 6 and the outer diameter C of the cage 8 = (shaft diameter B + roller diameter × 2) −outer diameter C of the cage 8. It will not be.
That is, the outer diameter guide clearance of the retainer 8 = (shaft diameter B + roller diameter × 2) −outer diameter dimension A> 0 of the retainer 8, thereby setting the outer diameter surface of the retainer 8 relative to the inner diameter surface of the outer ring 6. , And the cage 8 rotates smoothly along with the roller revolution of the needle roller 7, thereby suppressing the occurrence of a feeling of backlash in the circumferential direction.

  In the first and second embodiments, the radial needle roller bearing is exemplified, but the present invention can also be applied to a normal radial roller bearing.

Sectional drawing which shows the bearing apparatus for steering columns of Embodiment 1 of this invention. The front view of the outer ring | wheel of the steering column bearing apparatus. Explanatory drawing which shows the manufacture process of the outer ring | wheel of the bearing apparatus for steering columns. Sectional drawing which shows the relationship with the outer ring | wheel place of the bearing apparatus for steering columns. The cross-sectional view which shows the steering column bearing apparatus of Embodiment 2 of this invention.

Explanation of symbols

  1 shaft box, 2 shafts, 3 steering column bearing device, 4 bearing housing case, 5 radial needle roller bearing, 6 outer ring, 7 radial needle roller, 8 cage, 14 convex part.

Claims (1)

A split outer ring formed into a cylindrical shape by bending a steel plate, a plurality of rollers arranged inside the outer ring so as to be able to roll and arranged at predetermined intervals in the circumferential direction, and a cage for holding these rollers. A radial roller bearing having a shaft inserted therethrough;
An annular bearing housing case that is fitted on the outer periphery of the outer ring and made of an elastic material;
A radial roller bearing device comprising:
The width in the outer ring circumferential direction of the convex portion protruding inward that occurs during processing of the outer ring is such a size that at least two adjacent rollers are mounted,
An inner diameter surface of the outer ring is pressurized Paste direction radially outer surface of said retainer by a compression elastic preload of the bearing housing case is provided between the outer diameter surface of the cage, have a following gap ,
(Gap) =
{(Diameter of the shaft) + (diameter of the roller) × 2- (outer diameter of the cage)} / 2> 0
The steel plate is a plurality of strip steel plates connected by a connecting portion,
The outer ring is formed by cutting the connecting portion after the steel plate is bent,
The convex portion is a convex portion generated in a region connected by the connecting portion.
A radial roller bearing device characterized by that.

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