JPH0568355A - Bearing device - Google Patents

Abstract

PURPOSE:To reduce the number of part items and man-hours, in an assembly process, by attaining extension of a motor life and contriving lightness, thinness and shortness of a motor, in the case of a thrust bearing device used for the small motor for use of various electrical equipments. CONSTITUTION:A bearing plate 11 for receiving a load in a thrust direction of a shaft 3 is constituted of an alloy of general purpose resin of low melting point and heat resisting resin of high melting point. The heat resisting resin of high melting point is not changed to support the load in the thrust direction, and the general purpose resin of low melting point is melted to play a role of lubricant and to prevent the bearing plate from wearing, by sliding heat between the shaft 3 and the bearing plate 11. When the shaft 3 is stopped to decrease a temperature, the molten general purpose resin of low melting point is again alloyed with the heat resisting resin of high melting point and returned to the original condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device, particularly a thrust bearing device, used for a small motor used in, for example, audio / video equipment, office equipment, industrial equipment and the like.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for small motors that are light, thin, short and small and have a long service life as the market for households and industrials expands.

An example of this motor is a brushless DC motor, which will be described with reference to FIG. In FIG. 4, reference numeral 3 denotes a shaft having an arcuate tip, which is rotatably supported by a sleeve bearing 4 provided on a frame 5 of a steel plate forming a skeleton of a motor and a sleeve bearing 9 provided on a metal printed circuit board 10. ing.

A rotor frame 2 to which a cylindrical magnet 1 having N and S poles alternately magnetized in the circumferential direction is fixed is attached to the shaft 3 to form a rotor.

An armature in which an armature winding 8 is wound around an iron core 6 with an insulator 7 interposed therebetween is used as the metal printed board 1
0, and the insulator 7 has a plurality of protrusions 15 which are inserted into the metal printed board 10 and sandwiched by the thrust support plate 14. The protrusions 15 are fixed to the thrust support plate 14 by welding. It constitutes the stator.

A bearing plate 11 for receiving the tip of the shaft 3 is provided at the center of the thrust support plate 14, and a lubricant 13 is applied to the surface of the bearing plate 11 to prevent the bearing plate 11 from being worn. is there.

In the above structure, when the shaft 3 is supported by the sleeve bearings 4 and 9 and rotates, a load in the thrust direction generated by the magnetic attractive force of the rotor is applied to the bearing plate 11.
It is structured to be received at.

[0008]

In the conventional small motor such as the brushless DC motor, the bearing plate 1 receives the load in the thrust direction from the shaft 3 rotating at high speed.
1 is very easy to wear, which reduces frictional resistance,
In general, the lubricant 13 is applied to the surface of the bearing plate 11 in order to suppress heat generation due to friction and to supplement the wear resistance of the bearing plate 11. However, it is necessary to uniformly apply the lubricant 13 to the surface of the bearing plate 11 in order to achieve a long service life, which requires a large number of assembly steps. Especially when used in a high temperature environment, the lubricant 13 deteriorates and wears out. There is a problem that the original performance of prevention cannot be maintained.

In view of the above problems, the present invention aims to reduce the number of members and reduce the wear due to the sliding motion of the shaft 3 and the bearing plate 11 of a small motor.

[0010]

In order to achieve the above object, the present invention has a structure in which an alloy of a general-purpose resin having a low melting point and a heat-resistant resin having a high melting point is used for a bearing plate.

[0011]

By the above means, wear of the bearing plate that receives a load in the thrust direction from the shaft that rotates at high speed without using a lubricant is prevented and the life of the motor is extended.

[0012]

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

(Embodiment 1) FIG. 1 is a sectional view of a motor having a bearing device according to a first embodiment of the present invention.

Except for the lubricant 13 and the bearing plate 11, the structure is the same as that of the conventional structure. The difference is that the lubricant 13 is eliminated and an alloy of a general-purpose resin having a low melting point and a heat-resistant resin having a high melting point is used for the bearing plate 11. In that respect, the operation will be described below with reference to FIG.

When the shaft 3 rotates, sliding occurs between the shaft 3 and the bearing plate 11, and heat is generated in a small portion of the sliding portion. Due to this heat generation, the heat-resistant resin having a high melting point does not change and supports the load in the thrust direction, and the general-purpose resin having a low melting point serves as a lubricant and prevents the bearing plate 11 from being worn.

When the shaft 3 stops and the temperature drops,
The molten low melting point general-purpose resin is alloyed with the high melting point heat resistant resin and returns to the original state.

Here, 66 nylon, 6 nylon, polyacetal, or ultra-high molecular weight polyethylene is used as the low melting point general resin, and polyphenylene sulfide, polyether sulfone, polyether ether ketone, fragrance is used as the high melting point heat resistant resin. Any of the group polyamides are used.

As described above, according to this embodiment, the bearing plate 1
By configuring 1 as an alloy of a general-purpose resin having a low melting point and a heat-resistant resin having a high melting point, wear of the bearing plate 11 can be prevented, the lubricant 13 can be eliminated, and the number of assembling steps can be reduced.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to FIG.

FIG. 3 is a cross-sectional view of a motor showing a second embodiment, except that the bearing plate is made up of the thrust support plate itself.
The configuration and operation are exactly the same as those of the embodiment.

As described above, according to this embodiment, the lubricant 1
3 and the bearing plate 11 are abolished, and the thrust support plate 14 is made of an alloy of a general-purpose resin having a low melting point and a heat-resistant resin having a high melting point to prevent the wear of the thrust supporting plate, and to reduce the weight, thickness, size, and parts in the assembly process The number of points and the number of assembly steps can be reduced.

[0022]

As described above, according to the present invention, since the bearing plate 11 is made of an alloy of a general-purpose resin having a low melting point and a heat-resistant resin having a high melting point, the wear resistance of the bearing plate 11 is improved and a long life can be achieved. Moreover, the motor can be made lighter, thinner, shorter and smaller, the number of parts can be reduced, and the assembling process can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a motor having a bearing device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a bearing device according to a first embodiment of the present invention.

FIG. 3 is a sectional view of a motor having a bearing device according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a motor having a conventional bearing device.

[Explanation of symbols]

 1 Magnet 2 Rotor Frame 3 Shaft 4 Sleeve Bearing 5 Frame 6 Iron Core 7 Insulator 8 Armature Winding 9 Sleeve Bearing 10 Printed Circuit Board 11 Bearing Plate 12 Connection Pin 13 Lubricant 14 Thrust Support Plate 15 Projection

Claims (5)

[Claims] 1. A bearing plate for supporting an end portion of a shaft is composed of an alloy of a general-purpose resin having a self-lubricating property, a low friction coefficient and a low melting point, and a heat-resistant resin having a high heat resistance and a high strength and a high melting point. A bearing device characterized by the above. 2. The bearing device according to claim 1, wherein the general-purpose resin is composed of any one of 66 nylon, 6 nylon, polyacetal, and ultra-high molecular weight polyethylene. 3. The heat resistant resin is polyphenylene sulfide,
The bearing device according to claim 1, wherein the bearing device is made of any one of polyether sulfone, polyether ether ketone, and aromatic polyamide. 4. The bearing device according to claim 1, wherein the bearing plate is provided between the thrust support plate and the sleeve bearing. 5. The bearing device according to claim 1, wherein the bearing plate comprises the thrust support plate itself.