JPH0783236A - Bearing device - Google Patents

Abstract

PURPOSE:To control with high accuracy a bearing clearance on a bearing face by preventing contraction due to press fitting at the inner diameter part of a bearing sleeve. CONSTITUTION:A plurality of protrusions 2 protruded outside the diameter direction and inclined in the peripheral direction are integrally formed on the outer peripheral part 6 of a bearing sleeve 1. Thus, the protrusions 2 are deflected in the inclined direction toward the peripheral direction in press-fitting the bearing sleeve 1 in the inner peripheral part of a stationary member. Thus, fastening force transferred to the inner peripheral part 3 of the bearing sleeve 1 from the stationary member is relaxed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device capable of preventing deformation of a bearing surface.

[0002]

2. Description of the Related Art Generally, when a plain bearing is used as a bearing device, its shaft and sleeve are used by being fixed to another structural portion by a method such as press fitting or adhesion. In particular, fixing by press fitting is simple and inexpensive, and is therefore often used.

FIG. 7 shows a conventional bearing device which adopts the fixing by press fitting. As shown in FIG. 7A, this bearing device is assembled by press-fitting and fixing the bearing sleeve 71 on the inner peripheral surface 75 of the cylindrical fixing member 72. In this bearing device, a rotating shaft (not shown) is inserted into the inner peripheral surface 73 of the bearing sleeve 71, and the inner peripheral surface 73 of the bearing sleeve 71 supports the rotating shaft. For example, when the bearing device is a dynamic pressure bearing, a dynamic pressure groove is formed on the inner peripheral surface 73 of the bearing sleeve 71, and the rotary shaft is supported by the dynamic pressure generated by the dynamic pressure groove. Of.

However, in the above bearing device, the bearing sleeve 71 is press-fitted and fixed to the fixing member 72.
As shown in, the bearing sleeve 71 is tightened from the outer diameter side by the fixing member 72. Then, due to this tightening, the inner diameter portion of the bearing sleeve 71 contracts and the inner diameter dimension decreases. Therefore, the inner peripheral surface 73 of the bearing sleeve 71
The bearing clearance between the shaft and the rotating shaft is reduced.

As described above, the bearing device has a problem that it is difficult to control the dimension of the bearing gap with high accuracy because the bearing gap is changed by press fitting.

Therefore, as shown in FIG. 8A, when a plurality of triangular protrusions 82 extending in the normal direction are formed on the outer peripheral surface 86 of the bearing sleeve 81 and the bearing sleeve 81 is press-fitted into the fixing member. In addition, a slight deformation of the protrusion 82 relaxes the tightening force transmitted from the fixing member to the bearing sleeve 81 to prevent the inner diameter of the cylindrical bearing surface 83 from being reduced. As the above-mentioned protrusions, the rectangular protrusions 92 shown in FIG. 8B and the protrusions shown in FIG.
The curved projection 102 shown in FIG.

[0007]

However, the above-mentioned protrusion is
Since it extends in the normal direction, as shown in FIG. 3 (C), when receiving the tightening force from the inner diameter portion of the fixing member, the tightening force is transmitted to the bearing sleeve 86 on the inner diameter side almost as it is. Resulting in. Therefore, even in the conventional example shown in FIG. 8, contraction of the inner diameter portion of the bearing sleeve occurs,
There is a problem that the dimensions of the bearing gap cannot be managed with sufficiently high accuracy.

SUMMARY OF THE INVENTION An object of the present invention is to provide a bearing device capable of preventing the inner diameter portion of the bearing sleeve from contracting due to press fitting and managing the bearing gap on the bearing surface with high accuracy.

[0009]

In order to achieve the above object, the bearing device according to the invention of claim 1 is such that a bearing sleeve for supporting a rotary shaft inserted into an inner peripheral surface serving as a bearing surface has a fixing hole for a fixing member. In the bearing device press-fitted into and fixed to the fixing member, the pressure applied from the fixing member to the bearing surface of the bearing sleeve is relaxed by contacting and deforming the inner peripheral surface of the mounting hole of the fixing member or the outer peripheral surface of the bearing sleeve. The pressure relief portion for preventing the deformation of the bearing surface is formed integrally with one of the outer peripheral portion of the bearing sleeve and the inner peripheral portion of the mounting hole of the fixing member.

According to a second aspect of the present invention, there is provided the bearing device according to the first aspect, wherein the pressure relief portion is integrally formed with an outer peripheral portion of the bearing sleeve or an inner peripheral portion of a mounting hole of the fixing member. A plurality of projections that are formed so as to project radially outward or radially inward in a circumferential direction, the projections contacting the inner peripheral surface of the mounting hole of the fixing member or the outer peripheral surface of the bearing sleeve. It is characterized by being in contact with each other.

According to a third aspect of the present invention, there is provided the bearing device according to the first aspect, wherein the pressure relief portion is integrally formed with an outer peripheral portion of the bearing sleeve or an inner peripheral portion of a mounting hole of the fixing member. It is characterized in that it is provided with a projecting portion that is formed and projects radially outward or radially inward, and a cavity portion that is formed inside the projecting portion.

[0012]

According to the invention of claim 1, when the bearing sleeve is press-fitted into the mounting hole of the fixing member, the pressure relaxation portion is deformed, and the pressure applied from the fixing member to the bearing surface of the bearing sleeve is relaxed.
Prevents deformation of the bearing surface. Therefore, contraction of the inner diameter portion of the bearing sleeve due to press fitting is prevented, the bearing sleeve is fixed to the fixing member without reducing the inner diameter dimension, and the bearing gap on the bearing surface is managed with high accuracy.

According to a second aspect of the present invention, the pressure relief portion includes a plurality of protrusions, and the protrusions are inclined and protrude in the circumferential direction. Therefore, when the bearing sleeve is press-fitted into the mounting hole of the fixing member. The projection bends, the pressure applied from the fixing member to the bearing surface of the bearing sleeve is relieved, and the deformation of the bearing surface is prevented.

According to the third aspect of the present invention, since the pressure relaxation portion includes the protruding portion protruding in the radial direction and the hollow portion formed inside the protruding portion, the bearing sleeve is fitted in the mounting hole of the fixing member. When is press-fitted, the protruding portion is recessed toward the hollow portion, the pressure applied from the fixing member to the bearing surface of the bearing sleeve is relieved, and the deformation of the bearing surface is prevented.

[0015]

The present invention will be described in detail below with reference to the embodiments shown in the drawings.

FIG. 1 shows a bearing sleeve 1 of a dynamic pressure bearing device which is an embodiment of the bearing device of the present invention. The bearing sleeve 1 is made of resin and has a plurality of tapered projections 2, 2.
Are integrally formed on the outer peripheral portion 6. The protrusion 2 extends radially outward and is inclined in the circumferential direction.

A plurality of dynamic pressure grooves 5 are formed on the inner peripheral portion 3 of the bearing sleeve 1. When a rotary shaft (not shown) is inserted into the inner peripheral portion 3 of the bearing sleeve 1 and the rotary shaft rotates, the dynamic pressure groove 5 forms a fluid between the rotary shaft and the bearing sleeve 1. A dynamic pressure is generated on the shaft to support the rotating shaft in the radial direction.

As shown in FIG. 2 (A), the dynamic bearing device of this embodiment is assembled by press-fitting the bearing sleeve 1 into the inner peripheral portion 12 of a cylindrical metal fixing member 11. .

As shown in FIG. 3A, at the time of press-fitting in the above-mentioned assembly, the tips of the projections 2 formed on the outer peripheral portion 6 of the bearing sleeve 1 come into contact with the inner peripheral portion 12 of the fixing member 11, and The pressure P that is directed inward in the radial direction is received from the peripheral portion 12. Then, the protrusion 2 bends inward in the radial direction, absorbs the pressure P, and relaxes the pressure transmitted to the inner peripheral portion 3 of the bearing sleeve 1. Therefore, according to this embodiment, when the bearing sleeve 1 is press-fitted into the fixing member 11, it is possible to prevent the inner peripheral portion 3 of the bearing sleeve 1 from being compressed and deformed. Therefore, it is possible to prevent the roundness of the inner peripheral surface of the inner peripheral portion 3 of the bearing sleeve 1 from being impaired by the press-fitting, and the inner peripheral surface of the inner peripheral portion 3 of the bearing sleeve 1, that is, the bearing surface and the bearing surface. The size of the bearing gap between the rotary shaft to be inserted can be controlled with high accuracy. The size of the bearing gap is several μm
In the dynamic bearing device, it is very important that the dimension of the bearing gap can be controlled with high accuracy.

In the above embodiment, the plurality of projections 2 inclined in the circumferential direction are integrally formed on the outer peripheral portion 6 of the bearing sleeve 1. However, as shown in FIG. A plurality of protrusions 23, 23 ... Inclined in the circumferential direction may be integrally formed on the inner peripheral portion 25 of the cylindrical fixing member 22 without providing any protrusion.

Although the projection 2 is tapered in the above embodiment, it may be square as shown in FIG.

As shown in FIG. 5 (A), instead of the projection 2, a concave portion 41 is formed at the base of the inclined side, and a tapered projection 51 having a sharp tip is formed on the outer peripheral portion 6 of the bearing sleeve 1.
It may be formed integrally with. By providing the concave portion 41, the root portion of the protrusion 51 can move to the concave portion 41 when the protrusion 51 bends, so that the pressure transmitted radially inward from the root portion can be reduced. Therefore, the tightening force at the time of press fitting can be further alleviated.

Further, instead of the protrusion 2, a protrusion 52 as shown in FIG. 5B may be formed. Further, instead of the protrusion 2, as shown in FIG. 5C, a rectangular protrusion 53 inclined in the circumferential direction and a rectangular recess 42 formed on the inclined side of the protrusion 53 are formed. Good. Also in this case, when the projection 53 is bent and tilted,
Therefore, the tightening force at the time of press fitting can be further alleviated.

Further, instead of the projection 2, as shown in FIG. 5 (D), a rectangular projection 55 extending in both tangential directions of the outer peripheral portion of the bearing sleeve and a radial projection inward of the rectangular projection 55 are formed. The formed rectangular recess 43 may be formed on the outer peripheral portion of the bearing sleeve. Also in this case, since the rectangular protrusion 55 can be accommodated in the rectangular recess 43, the tightening force at the time of press fitting can be further alleviated.

Further, in place of the projection 2, as shown in FIG. 5 (E), a protruding portion 56 protruding in the radial direction and a hollow portion 57 radially inward of the protruding portion 56 are provided in the bearing sleeve 1. It may be formed on the outer peripheral portion 6. In this case, when the bearing sleeve 1 is press-fitted into the mounting hole of the fixing member 11, the protrusion 5
6 is depressed toward the hollow portion 57, so that the pressure applied from the fixing member 11 to the bearing surface of the bearing sleeve 1 can be relieved, and the deformation of the bearing surface can be prevented.

Further, as shown in FIG. 5 (F), a round head-like projection 58 is formed on the outer peripheral portion 6 of the bearing sleeve 1 so as to project outward in the radial direction and has a constricted root. The both sides in the direction may be recessed so that when the bearing sleeve 1 is press-fitted into the fixing member 11, the projection 58 is inclined in the circumferential direction to relieve the pressure applied to the bearing surface of the bearing sleeve 1. .

Further, the projection structure shown in FIGS. 5A to 5F may be formed on the inner peripheral portion of the fixing member into which the bearing sleeve is press-fitted.

Further, as shown in FIG. 2 (B), the fixing member 2
When the protrusion 23 is formed on the inner peripheral portion 25 of the second outer peripheral portion of the bearing sleeve 21, the outer peripheral portion of the bearing sleeve 21 is radially outward so that the central portion in the axial direction has the maximum diameter as shown in FIG. When curved, the bearing sleeve 21 can swing with respect to the inner peripheral portion 25 of the fixing member 22 around the center portion. Therefore, in this case, the aligning property of the bearing sleeve can be obtained. As shown in FIG. 6B, even when the outer peripheral portion of the bearing sleeve 21 is tapered outward in the radial direction so that the central portion in the axial direction becomes the apex, the adjustment of the bearing sleeve 21 is performed. Core property can be obtained.

Further, as shown in FIG. 2 (A), when the protrusion 2 is formed on the outer peripheral portion of the bearing sleeve 1, the inner peripheral portion 12 of the fixing member 11 is, as shown in FIG. 6 (C), When the bearing sleeve 1 is curved inward in the radial direction so that the inner diameter of the central portion in the axial direction is minimized, the bearing sleeve 1 can swing around the portion in contact with the central portion to obtain the centering property. be able to.

Although the bearing sleeve 1 is made of resin and the fixing member 11 is made of metal in the above embodiment, the bearing sleeve 1 may be made of metal and the fixing member 11 may be made of resin. Further, both the bearing sleeve and the fixing member may be made of resin, and both the bearing sleeve and the fixing member may be made of metal.

[0031]

As is apparent from the above, according to the invention of claim 1, the pressure relief portion integrally formed on one of the outer peripheral portion of the bearing sleeve and the inner peripheral portion of the mounting hole of the fixing member has the mounting hole of the fixing member. The inner peripheral surface or the outer peripheral surface of the bearing sleeve is contacted and deformed to relieve the pressure applied from the fixing member to the bearing surface of the bearing sleeve and prevent the deformation of the bearing surface. Therefore, according to the first aspect of the present invention, it is possible to prevent the inner diameter portion of the bearing sleeve from shrinking due to press fitting, and to fix the bearing sleeve to the fixing member without reducing the inner diameter portion of the inner peripheral portion. The bearing clearance on the surface can be controlled with high accuracy.

Further, in the invention of claim 2, the pressure relaxation portion is integrally formed with the outer peripheral portion of the bearing sleeve or the inner peripheral portion of the mounting hole of the fixing member, and is circularly outward in the radial direction or inward in the radial direction. A plurality of protrusions that are inclined and project in the circumferential direction are provided, and the protrusions are configured to abut the inner peripheral surface of the mounting hole of the fixing member or the outer peripheral surface of the bearing sleeve. Therefore, according to the invention of claim 2, when the bearing sleeve is press-fitted into the mounting hole of the fixing member, the protrusion bends,
The pressure applied from the fixing member to the bearing surface of the bearing sleeve is relieved to prevent deformation of the bearing surface. Therefore, according to the second aspect of the invention, it is possible to prevent the inner diameter portion of the bearing sleeve from contracting due to press fitting, and it is possible to manage the bearing gap on the bearing surface with high accuracy.

According to a third aspect of the present invention, the pressure relief portion is formed integrally with the outer peripheral portion of the bearing sleeve or the inner peripheral portion of the mounting hole of the fixing member, and is radially outward or radially inward. Since it has a protruding portion and a hollow portion formed inside the protruding portion, when the bearing sleeve is press-fitted into the mounting hole of the fixing member, the protruding portion is depressed toward the hollow portion, The pressure applied from the fixing member to the bearing surface of the bearing sleeve is relieved to prevent deformation of the bearing surface. Therefore, according to the third aspect of the invention, it is possible to prevent the inner diameter portion of the bearing sleeve from contracting due to press fitting, and it is possible to manage the bearing gap on the bearing surface with high accuracy.

[Brief description of drawings]

FIG. 1 (A) is a top view of a bearing sleeve of an embodiment of the bearing device of the present invention. FIG. 1B is a half sectional view of the bearing sleeve of the above embodiment.

FIG. 2 (A) is a view showing how a bearing sleeve is press-fitted into the fixing member of the above embodiment. FIG. 2B is a diagram showing a modification of the above embodiment.

FIG. 3 (A) is a cross-sectional view of the vicinity of the protrusion 2 of the above embodiment. FIG. 3B is a cross-sectional view near the protrusion 32 of the modified example of the above embodiment. FIG. 3C is a cross-sectional view near the protrusion 82 of the conventional example.

FIG. 4 is a top view of a bearing sleeve of a modified example of the above embodiment.

FIG. 5 is a view showing a modified example of the protrusion of the bearing sleeve of the above embodiment.

6 (A) and 6 (B) are cross-sectional views of a modified example of the bearing sleeve of the above embodiment. FIG. 6C is a sectional view of a modification of the fixing member of the above embodiment.

FIG. 7 (A) is a view showing how a bearing sleeve of a conventional bearing device is press-fitted into a fixing member. FIG. 7 (B) is a view showing the above conventional bearing device in which the bearing sleeve is press-fitted into the fixing member.

FIG. 8 is a view showing another conventional bearing sleeve.

[Explanation of symbols]

1,21 ... Bearing sleeve, 2,23,32,51,52,5
3, 55 ... Protrusion, 3 ... Inner peripheral portion, 5 ... Dynamic pressure groove, 6, 36 ...
Outer peripheral portion 11, 22 ... Fixing member, 12, 25 ... Inner peripheral portion,
56 ... Projection, 57 ... Cavity.

Claims (3)

[Claims] 1. A bearing device in which a bearing sleeve for supporting a rotating shaft, which is inserted into an inner peripheral surface serving as a bearing surface, is press-fitted and fixed in a mounting hole of a fixing member, wherein an inner peripheral surface of the mounting hole of the fixing member or An outer peripheral portion of the bearing sleeve is provided with a pressure relaxation portion that abuts against the outer peripheral surface of the bearing sleeve and deforms to relieve pressure applied to the bearing surface of the bearing sleeve from the fixing member and prevent deformation of the bearing surface. Alternatively, the bearing device is formed integrally with one of the inner peripheral portions of the mounting holes of the fixing member. 2. The bearing device according to claim 1, wherein the pressure relaxation portion is formed integrally with an outer peripheral portion of the bearing sleeve or an inner peripheral portion of a mounting hole of the fixing member, and is radially outward or radial. A plurality of protrusions protruding inward in the circumferential direction, the protrusions being in contact with the inner peripheral surface of the mounting hole of the fixing member or the outer peripheral surface of the bearing sleeve. Bearing device. 3. The bearing device according to claim 1, wherein the pressure relief portion is formed integrally with an outer peripheral portion of the bearing sleeve or an inner peripheral portion of a mounting hole of the fixing member, and is radially outward or radial direction. A bearing device, comprising: a protrusion that protrudes inward; and a cavity that is formed inside the protrusion.