JP2974887B2 - Dynamic pressure bearing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic pressure bearing device which can be easily mounted.

[0002]

2. Description of the Related Art Conventionally, as a dynamic bearing device of this kind,
In some cases, a cylindrical dynamic pressure bearing body is attached to an attachment hole of a housing via an O-ring as an elastic material. An annular groove into which the O-ring is fitted is formed on the peripheral surface of the mounting hole of the housing. By fitting the O-ring into the annular groove, the O-ring and the dynamic pressure bearing body are prevented from moving in the axial direction.

In this dynamic pressure bearing device, a shaft is inserted into the cylindrical dynamic pressure bearing body, and the shaft is rotated to form a dynamic pressure groove formed on an inner peripheral surface of the dynamic pressure bearing body. A dynamic pressure is generated in the fluid between the shaft and the shaft, and the dynamic pressure supports the shaft.

[0004]

In the above-mentioned conventional hydrodynamic bearing device, since the O-ring fixes the hydrodynamic bearing to the housing, a groove for positioning and fixing the O-ring is formed. It must be formed on the inner peripheral surface of the mounting hole of the housing.

[0005] Further, the O-ring alone may not provide sufficient restraining force in the axial direction. In this case, for example, a projection for locking the hydrodynamic bearing body in the axial direction is provided inside the housing. It must be provided on the peripheral surface.

However, it is generally difficult to form grooves or protrusions on the peripheral surface of the hole of the housing, and there is a problem that the cost of the processing increases the cost of the bearing device. Therefore, an object of the present invention is to provide a dynamic pressure bearing device that can firmly fix a dynamic pressure bearing body to a housing without forming a groove or a projection in the housing.

In order to achieve the above object, a dynamic pressure bearing device according to the present invention is a dynamic pressure bearing device in which a cylindrical dynamic pressure bearing is mounted in a mounting hole of a housing via an elastic material. The dynamic pressure bearing body has a substantially drum shape in which an outer diameter of an axially intermediate portion of an outer peripheral surface is formed smaller than outer diameters of both axial end portions, and the elastic material is formed in a circular tube shape, It is characterized in that the inner diameter is formed smaller than the maximum outer diameter of the dynamic pressure bearing body.

[0007]

According to the above construction, when the dynamic pressure bearing is inserted into a cylindrical elastic material, both ends of the dynamic pressure bearing in the axial direction bite into the inner peripheral surface of the elastic material. At this time, the inner peripheral surface of the elastic material is pressed against the outer peripheral surface of the axially intermediate portion of the dynamic pressure bearing body. For this reason, the dynamic pressure bearing body is firmly fixed to the elastic material. The cylindrical elastic material is inserted into the mounting hole of the housing, is compressed between the inner peripheral surface of the housing and the outer peripheral surface of the dynamic pressure bearing, and is fixed to the housing.

Therefore, according to the present invention, unlike the conventional example, the hydrodynamic bearing body can be firmly fixed to the housing without subjecting the inner peripheral surface of the housing to groove processing or projection processing. Therefore, according to the present invention, the manufacturing cost is reduced, and the assembling of the dynamic pressure bearing body to the housing is facilitated.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 shows a cross section of an embodiment of the hydrodynamic bearing device according to the present invention. This embodiment has cylindrical dynamic pressure bearing bodies 3 and 3 attached to an attachment hole 2a of a housing 2 via a cylindrical elastic material 1. The dynamic pressure bearing body 3
A dynamic pressure groove 5 is formed on the inner peripheral surface 3a.

As shown in FIG. 2, the dynamic pressure bearing body 3
The outer peripheral surface center portion 31 is narrowed and narrowed. Therefore, the dynamic pressure bearing body 3 is formed in the axially central portion 3 of the outer peripheral surface 3b.
1 is formed to be smaller than the outer diameter D2 of the axial ends 33 and 34.

The inner diameter D3 of the elastic member 1 is formed smaller than the maximum outer diameter D2 of the dynamic pressure bearing body 3.
The elastic member 1 can be easily manufactured by using a rubber or resin tube cut to a desired length.

A shaft 6 is inserted into the dynamic bearing 3, and when the shaft 6 rotates, a dynamic pressure is generated in the fluid between the shaft 6 and the dynamic bearing 3, and the bearing 3 is rotated.
, The shaft 6 is supported.

The dynamic pressure bearing device having the above-described structure is characterized in that:
When the dynamic pressure bearing 3 is inserted into the elastic member 1, the ends 33 and 34 of the dynamic pressure bearing 3 bit into the elastic member 1 as shown in FIG. At this time, the elastic member 1 is pressed against the axial center portion 31 of the dynamic pressure bearing body 3.

Thus, the dynamic pressure bearing member 3 is firmly fixed to the elastic member 1. The cylindrical elastic material 1 is inserted into the mounting hole 2 a of the housing 2, compressed between the inner peripheral surface of the housing 2 and the outer peripheral surface of the dynamic pressure bearing 3, and fixed to the housing 2. You.

Therefore, according to this embodiment, unlike the conventional example, the dynamic pressure bearing body 3 can be firmly fixed to the housing 2 without subjecting the inner peripheral surface of the housing 2 to groove processing or projection processing. it can. Therefore, according to this embodiment, the manufacturing cost is reduced, and the assembling of the dynamic pressure bearing body 3 to the housing 2 can be facilitated.

Further, the elastic member 1 having the shape of a circular tube has the following features.
Since the dynamic pressure bearing 3 is fixed to the housing 2, the inner diameter of the dynamic pressure bearing 3 is not distorted. For this reason, the dimensional accuracy of the inner diameter of the dynamic pressure bearing 3 is improved, and the clearance between the shaft 6 and the dynamic pressure bearing 3 can be accurately set. Further, even if the shaft 6 vibrates and whirls around, the shock caused by the vibration can be buffered by the elastic member 1. Further, since the dynamic pressure bearing body 3 is supported by the elastic material 1, there is alignment with the shaft 6. Further, since the outer diameter D2 of the axial end portions 33 and 34 is larger than the outer diameter D1 of the central portion, when the dynamic pressure bearing body 3 is inserted into the elastic material 1, Since only the outer diameter D2 of the end portion is in contact with the inner peripheral surface of the elastic member 1, the frictional resistance at the time of insertion is small and the dynamic pressure bearing body 3 is connected to the elastic member 1.
Can be inserted easily.

[0018]

As is apparent from the above description, in the dynamic pressure bearing device of the present invention, the cylindrical dynamic pressure bearing body attached to the housing via the cylindrical elastic body is provided at the axially intermediate portion of the outer peripheral surface. Is formed smaller than the outer diameter of both ends in the axial direction, and the inner diameter of the elastic material is formed smaller than the maximum outer diameter of the dynamic pressure bearing body.

Therefore, according to the present invention, when the dynamic pressure bearing is inserted into the cylindrical elastic material, both ends in the axial direction of the dynamic pressure bearing bit into the inner peripheral surface of the elastic material. ,
Since the inner peripheral surface of the elastic member presses against the outer peripheral surface of the axially intermediate portion of the dynamic pressure bearing member, the dynamic pressure bearing member can be firmly fixed to the elastic material.

The cylindrical elastic material is inserted into the mounting hole of the housing, is compressed between the inner peripheral surface of the housing and the outer peripheral surface of the hydrodynamic bearing, and is compressed by its elasticity.
Fixed to the housing.

Therefore, according to the present invention, unlike the conventional example, the hydrodynamic bearing can be firmly fixed to the housing without subjecting the inner peripheral surface of the housing to groove processing or projection processing. Therefore, according to the present invention,
It is possible to realize a dynamic pressure bearing device in which the manufacturing cost is low and the dynamic pressure bearing body can be easily attached to the housing.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of a dynamic pressure bearing device of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Circular elastic body, 2 ... Housing, 2a ... Mounting hole, 3 ... Cylindrical elastic body, 3a ... Inner peripheral surface, 5 ... Dynamic pressure groove, 6 ... Shaft, 31 ... Axial center part, 33 , 34 ...
Axial end, D1: outer diameter of axial central portion 31, D2: outer diameter of axial ends 33, 34, D3: inner diameter of elastic material 1.

Claims (1)

(57) [Claims] 1. A dynamic pressure bearing device in which a cylindrical dynamic pressure bearing body is mounted in a mounting hole of a housing via an elastic material, wherein the dynamic pressure bearing body has an outer diameter at an axially intermediate portion of an outer peripheral surface. The elastic material is formed in a tubular shape, and the inner diameter is formed smaller than the maximum outer diameter of the dynamic pressure bearing body. Characteristic hydrodynamic bearing device.