JP2976631B2 - Bearing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to audio, OA equipment,
The present invention relates to a bearing device provided with a tapered triangular groove on an inner surface of an oil-impregnated bearing of a motor used for industrial equipment and the like.

[0002]

2. Description of the Related Art In recent years, oil-impregnated bearings have been required to have centrality characteristics in which a rotor shaft slides at the center.

[0003] A conventional bearing device of a hydrodynamic bearing specification will be described below. FIG. 5 shows a sectional view of a conventional bearing device of a fluid bearing specification. As shown in FIG. 5, on the outer surface of the shaft 13 in the housing 12 of the bearing device, a parallel groove 14 of a fluid concentration portion having a group shape is formed by etching or rolling.

The operation of the bearing device configured as described above will be described below. First, the space between the housing 12 and the shaft 13 is filled with a fluid (including a magnetic fluid). When the motor rotates, the parallel grooves 14
The concentration of the fluid occurs at the intersection of the slices from above and below, which has the effect of turning the axis 13 toward the center.

[0005]

However, in the above-mentioned conventional configuration, it is difficult to perform group machining on the outer surface of the shaft.
In addition, since the fluid must always be filled between the housing and the shaft without any gap, a fluid seal for preventing leakage is required, and the structure becomes complicated. Further, there is another problem that the sealing effect of the fluid seal determines the service life.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a bearing device which can sufficiently exert a bearing effect.

[0007]

In order to achieve this object, a bearing device according to the present invention is provided with a mechanism for rotating an inner surface of an oil-impregnated bearing with a rotor shaft.
An oil sump can be formed in the rolling contact part corresponding to the shaft rotation direction.
Deploy a triangular groove in a tapered shape in the rotation direction so that
Open from the corner and form a non-voided part in the direction of the corner, then a vacant part,
The diameter extends from the non-porous portion to the
Has a tapered groove that expands, and also has a triangular shape.
Groove extends axially from non-porous to vacant
And the taper angle is 1/50 or less and the maximum depth
With a thickness of 10 μm or less.
These are microvoids.

[0008]

In this construction, a differential pressure is generated on the inner surface of the bearing due to the pump lubrication effect of the oil-impregnated bearing due to the rotation of the rotor shaft, and the oil generated by the compression and decompression is sent from the triangular groove to the narrow portion of the taper, whereby A wedge-shaped oil film is formed on the rotor shaft and the inner surface of the oil-impregnated bearing, so that the strength of the oil film is maintained between the rotor shaft and the oil-impregnated bearing, so that the rotation is smooth and the rotor shaft can be directed toward the center.

[0009]

An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, an oil-impregnated bearing 2 that supports a rotor shaft 1 is inserted into a housing 3. A rotor magnet 5 is attached to the rotor 4 fixed to the rotor shaft 1, and a winding coil 6 is attached to the housing 3. The oil-impregnated bearing 2 has a tapered triangular groove 7 and a hole 8. The rotor shaft 1 slides on the inner surface △ x of the oil-impregnated bearing 2. As shown in FIG. 2, a non-porous portion 9 having no pores or minute pores is provided by rolling and plastic working such as sizing around the portion where the rotor shaft 1 slides on the inner surface of the oil-impregnated bearing 2. The triangular groove 7 is formed over the hole 10. As shown in FIG. 3, the triangular groove 7 has a required triangular shape depending on the rotation direction of the rotor shaft 1. FIG. 3A shows a shape for left rotation and a straight triangle at the end in the rotation direction. Similarly, FIG. 3B shows a shape for right rotation and FIG. 3C shows a shape for both rotations. The triangular groove 7 has a taper angle of 1/50 or less and a groove depth of 10 μm.
It is as follows.

The operation of the bearing device configured as described above will be described with reference to FIG. First, when the rotor shaft 1 rotates, a pressurized portion is formed, and on the other hand, a decompression portion occurs, and the rotor shaft 1 is inserted inside the oil-impregnated bearing 2 as indicated by a dotted arrow.
The oil precipitates in the direction, and the oil is formed in a wedge-like oil film 11 on the sliding portion of the rotor shaft 1 and the oil-impregnated bearing 2 along the triangular groove 7 due to the sliding resistance due to the rotation of the rotor shaft 1. It creates a floating effect and a smooth sliding effect. The non-hollow portions 9 increase the pressurizing effect on the oil film strength in forming the oil film 11, and the triangular groove 7 is formed into a tapered shape so that the lubricating bearing 2 can be pump-lubricated. Exercise the function in the thrust direction. If it is not tapered, oil escapes from the holes 8 during pressurization, or the metal film is lubricated because the oil film 11 is not maintained, resulting in a large loss resistance and a great effect on characteristics and life. There is. Further, the effect of preventing rotation runout is obtained by fluid lubrication by a large number of oil films 11 formed in the direction of rotation of the inner surface of the oil-impregnated bearing 2, and a centrality effect in which the rotor shaft 1 slides at the center is provided.

As described above, according to the present embodiment, a triangular shape is formed across the non-hollow portion 9 provided around the sliding of the rotor shaft 1 on the inner surface of the oil-impregnated bearing 2 and the hollow portion 10 at the other end. By providing the groove 7, the oil film 11 is formed on the sliding portion of the rotor shaft 1 and the oil-impregnated bearing 2 along the triangular groove 7,
The centering effect that the center of the rotor shaft 1 slides is provided by the floating effect, smooth sliding effect, and rotational runout prevention effect of the rotor shaft 1. In addition, as for the shape of the triangular groove 7, when the taper angle is 1/50 or more and the groove depth exceeds 10 μm, oil shortage or the like may occur and metal contact may occur. Further, the oil-impregnated bearing 2 in which the periphery of the non-hollow portion 9 of the sliding portion with the rotor shaft 1 on the inner surface of the oil-impregnated bearing 2 has a minute hole portion is also effective.

[0013]

As is apparent from the above description of the embodiment, the present invention provides a triangular groove extending over a non-hollow portion around the sliding portion of the rotor shaft on the inner surface of the oil-impregnated bearing and a hollow portion at the other end. Thus, an oil film is formed on the rotor shaft and the sliding portion of the oil-impregnated bearing, thereby realizing an excellent bearing device having a centrality effect of sliding at the center of the rotor shaft.

[Brief description of the drawings]

1A is a sectional view of a bearing device according to a first embodiment of the present invention, FIG. 1B is a sectional view of an oil-impregnated bearing of the bearing device, and FIG.

FIG. 2 is an enlarged sectional view of the inner surface of an oil-impregnated bearing of the bearing device.

3A is a plan view of a triangular groove of the bearing device. FIG. 3B is a plan view of a triangular groove of the bearing device. FIG. 3C is a plan view of a triangular groove of the bearing device.

FIG. 4 (a) is a view of an inner diameter portion of a sliding portion of an oil-impregnated bearing of the bearing device.
Figure (b) is an explanatory cross-sectional view showing details of the sliding portion of the oil-impregnated bearing of the bearing device .

FIG. 5 is a sectional view of a conventional bearing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotor shaft 2 Oil-impregnated bearing 7 Triangular groove 9 Non-vacancy 10 Void

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02K 5/167 F16C 33/10 F16C 17/00-17/24

Claims (3)

(57) [Claims] 1. A bearing device comprising an oil-impregnated bearing which is in rotational contact with a rotor shaft via lubricating oil on an inner surface thereof, wherein oil is provided at a rotational contact portion of the inner surface of the oil-impregnated bearing with the rotor shaft in correspondence with the shaft rotation direction.
Triangle tapered in the direction of rotation so that a pool can be formed
A groove is provided, and a non-void portion is formed in the direction from the closing angle to the opening angle, and then
Form a hole with holes, and extend from both non-holes to both holes.
A bearing device having a tapered groove whose diameter increases toward a vacant hole . 2. The triangular groove has an opening angle that widens in the axial direction from a non-porous portion toward a vacant portion, and has a taper angle of 1/50 or less and a maximum depth of 10 μm or less. 2. The bearing device according to 1. 3. The bearing device according to claim 1, wherein the non-void portion is a minute hole.