JP2001224148A - Bearing device of motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device of a mortor which can block the movement of oil leaking out of an oil-impregnated bearing. SOLUTION: A fixing cap 35 and a bearing 24 face each other so as to be brought into slide contact with each other. A groove 35b are formed continuously, in the outer circumference of the fixing cap 35 in its rotation direction. The groove 35b is sufficiently deep, in comparison with the radial dimensions of the fixing cap 35.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor bearing device, and more particularly to a motor bearing device capable of preventing movement of oil leaking from an oil-impregnated bearing.

[0002]

2. Description of the Related Art Conventionally, there has been known a motor using an oil-impregnated bearing in order to rotate a motor rotating shaft with respect to a motor case at high efficiency. Oil-impregnated bearings are made by impregnating lubricating oil into a porous bearing made by compression-molding and firing copper or iron-based powder. By flowing to the surface, the sliding resistance with the motor rotation shaft is suppressed and the rotation efficiency is increased. However, while oil-impregnated bearings provide high-efficiency rotation, there is a problem in that oil leaking from inside the bearings adheres to places other than the bearings and hinders the operation of other parts.

[0003] For example, in a motor, oil leaking from an oil-impregnated bearing travels along a motor rotating shaft and adheres to a commutator (commutator segment), causing abnormal wear of a brush that slides on the commutator of the rotor. There's a problem. Also, if the brush powder scattered from the brush and the leaked oil are mixed and attached to the insulating portion between the commutator segments, there is a possibility that conduction failure may occur.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a motor bearing device capable of preventing movement of oil leaking from an oil-containing bearing.

[0005]

According to a first aspect of the present invention, there is provided a motor bearing device, comprising: a motor rotating shaft rotating in a motor case; and a motor rotating shaft provided on the motor rotating shaft. A rotating body that rotates integrally, and an oil-impregnated bearing having a thrust receiving surface slidable with the rotating body in the axial direction of the motor rotating shaft while rotatably supporting the motor rotating shaft provided in the motor case, An outer peripheral wall provided on an outer peripheral surface of the rotator along a rotational direction and for preventing movement of oil leaked from the oil-impregnated bearing.

According to the structure of the first aspect, the rotating body provided on the motor rotating shaft rotates integrally with the motor rotating shaft. The motor rotation shaft is rotatably supported by the oil-impregnated bearing. Further, the rotating body is slidable on the thrust end face of the oil-impregnated bearing, and regulates the movement of the motor rotating shaft in the thrust direction. That is, the oil-impregnated bearing supports the rotation direction and the axial direction of the motor rotation shaft. Here, with the rotation of the motor rotor, oil leaked from the sliding portion of the oil-impregnated bearing with the motor rotating shaft or the sliding portion with the rotating body may flow and move along the outer peripheral surface of the rotating body. According to the present invention, however, according to the present invention, since the outer peripheral wall is provided along the rotation direction of the rotating body, the oil cannot flow out beyond the outer peripheral wall, and the movement of the oil can be prevented.

According to a second aspect of the present invention, in the motor bearing device according to the first aspect, a commutator base fixed to the rotating shaft and a plurality of commutators fixed to the outer periphery of the commutator base at predetermined intervals. A piece, and the rotating body is integrally formed with the commutator base.

Thus, the movement of the oil flowing out of the oil-impregnated bearing on the outer peripheral wall is prevented, and the adhesion of the oil to the commutator can be prevented. Further, since the rotating body is integrated with the commutator base, the number of parts is reduced, which contributes to the cost reduction of the bearing device.
Furthermore, since the oil-impregnated bearing and the commutator can approach each other in the axial direction, the axial length of the motor can be reduced, and the motor can be downsized.

According to a third aspect of the present invention, there is provided a motor bearing device according to the first aspect, wherein a commutator base fixed to the rotary shaft and a plurality of commutator provided at predetermined intervals on an outer periphery of the commutator base. Wherein the rotating body is attached to the commutator base and forms a fixing member for fixing the commutator piece to the commutator base.

According to the third aspect of the present invention, the rotating body is
Since the fixing member for fixing the commutator piece to the commutator base is formed, the commutator can be easily assembled, and movement of the oil flowing out of the oil-impregnated bearing in the outer peripheral groove is prevented, and the oil to the commutator is prevented Can be prevented from adhering.

According to a fourth aspect of the present invention, in the motor bearing device according to any one of the first to third aspects, the rotating body is
It is characterized by being molded with resin. This facilitates the formation of the rotating body and contributes to a reduction in the weight of the motor.

[0012]

Next, an embodiment according to the present invention will be described with reference to the drawings. As shown in FIG. 1, an armature 10 is rotatably provided in a motor case 20 of the motor 1. The armature 10 is supported at two places by bearings 22 and 24 provided on a motor case 20, and a worm 10 a is provided at the tip thereof. These bearings 22 and 24 are oil-impregnated bearings. In other words, the lubricating oil is impregnated in a porous bearing formed by compression-molding and firing copper or iron-based powder, and the lubricating oil in the bearings 22 and 24 is rotated by the rotation of the motor rotation shaft 12. By flowing to the sliding surface, the sliding resistance with the armature 10 is suppressed, and the rotation efficiency is increased. And the bearing 22
Is fixed to the end of the yoke 26 of the motor case 20. The bearing 24 is fixed to an end of an end case 28 that holds the brush holder 29. Power supply brushes 29a, 29b made of carbon are held by the brush holder 29 so as to be movable in the radial direction of the motor rotating shaft 12, and the respective tips of the brushes 29a, 29b are connected to the motor rotating shaft (armature 10). And is slidably pressed against the commutator piece 38a of the commutator body 38 fixed to the main body 38.

As shown in FIG. 2, a core core 14 formed by laminating a plurality of core sheets in the axial direction is fixed to the motor rotating shaft 12. Each tooth 14a formed on the core iron core 14 is wound with a plurality of windings 16 as shown in FIG. Further, resin insulating sheets 30 are interposed on both sides in the axial direction of the core iron core 14 in order to prevent electrical conduction between the coil iron core 14 and the winding 16. The insulating sheet 30 is also formed continuously on the inner surface of each slot 14b (FIG. 2) formed between the teeth 14a.

As shown in FIG. 3, the insulating sheet 30 includes
A cylindrical first extension 32 and a second extension 34 that extend in the axial direction so as to cover the outer periphery of the motor rotation shaft 12 are integrally formed. First extension 32 and second extension 3
4 have the same diameter, the first extension 32 extends toward one end in the axial direction, while the second extension 34 extends toward the other end in the axial direction.

The first extension 32 is further integrally formed with a cylindrical third extension 36 extending toward one end in the axial direction (left side in FIG. 3) of resin. The third extension portion 36 has a shorter diameter than the first extension portion 32, and a plurality of commutator pieces 38a made of a copper plate are assembled on the outer peripheral surface thereof at predetermined intervals in the axial rotation direction. A main body 38 is configured. Specifically, a deep commutator groove 33 is formed along the axial direction between the first extension 32 and the third extension 36, and each commutator piece 38a is inserted into the groove 33, and furthermore, a circle made of resin. By fitting the annular fixing cap 35 to one end of the third extension, each commutator piece 38 is connected to the third extension 3.
6 are fixed at predetermined intervals around the circumference, and the commutator main body 38 is completed.

As shown in FIG. 1, the armature 10 has an axial center line P of the core iron core 14 fixed to the inner periphery of the yoke 26 in the motor case 20. The line Q is stored in a shifted state. Therefore, the armature 10 is always biased to one end in the axial direction (left side in FIG. 1) with its magnetic center shifted.

Here, as shown in FIG. 4, the armature 10 urged toward one end (left side in FIG. 4) has a distal end surface 34a of the second extension 34 at the other end.
0 (the thrust receiving surface) 22a of the bearing 22 provided at
, In the axial direction with a gap m interposed therebetween.
A grease housing groove 34b deep in the axial direction is formed in the distal end surface 34a of the second extension portion 34 in an annular shape around the axis of the motor rotation shaft 12, so that the grease housing groove 34b is embedded in the grease housing groove 34b. Grease G is provided in the gap m. Grease G has a relatively high viscosity and a gap m
Is always attached to

On the other hand, as shown in FIG.
Fixed cap 35 provided on the side facing the bearing 24
Is caused by the effect that the magnetic center of the armature 10 is shifted to one end side in the axial direction (left side in FIG. 5), and the end face 35a is
The side surface (thrust receiving surface) 24a of the (oil-bearing) can be slidably contacted. That is, the fixed cap 35 and the bearing 24 are
They are slidable against each other in the axial direction. The outer periphery of the fixed cap 35 is provided with a groove 35b formed continuously along the rotation direction. The groove 35b is formed to have a sufficient depth with respect to the radial dimension of the fixed cap 35. The outer peripheral wall 35c of the present invention is formed by the groove 35b.

Hereinafter, the operation of the motor bearing structure according to this embodiment will be described. According to the present embodiment, the fixed cap 35 that is attached to the tip of the third extension and forms the commutator main body 38 rotates integrally with the armature 10. The armature 10 is rotatably supported by bearings 22 and 24 (oil-containing bearings). Further, a fixed cap 35 is slidable on the axial side surface 24a of the bearing 24,
The movement of the armature shaft 10 in the axial direction is restricted. That is, the bearing 24 supports the armature 10 in the rotation direction and the axial direction.

Here, with the rotation of the armature 10, the oil which has flowed out from the side surface 24a of the bearing 24 (the sliding contact portion with the fixed cap 35) or the sliding portion with the motor rotating shaft 12,
When the oil flows and moves along the outer peripheral surface of the fixed cap 35 and oil adheres to the brushes 29a and 29b, the brushes 29a and 29
9b has a problem of causing abnormal wear. Also, brush 29
If the brush powder coming out of the a and 29b and the leaked oil adhere to the insulating portion between the commutator pieces 38a in a mixed state, there is a possibility that conduction failure may occur. However, according to the present embodiment, since the groove 35b is provided on the outer periphery of the fixed cap 35, the oil leaking from the bearing 24 is not removed from the groove 3b.
Even if it tries to flow into 5 b, the centrifugal force of the armature 10 causes the armature 10 to fly toward the outer periphery of the fixed cap 35. Even if the oil flows into the groove 35b, if the groove 35b has a sufficient depth, the oil cannot flow out beyond the groove 35b and the movement of the oil can be prevented. That is, the outer peripheral wall 35c is formed by the groove 35b. Therefore, the oil is commutator piece 3
8a can be prevented from adhering to the oil.

In this embodiment, when the outer peripheral wall 35c is formed, the groove 35b is formed.
Although the side surface of the concave portion is the outer peripheral wall 35c, the present invention is not limited thereto, and a wall having an end surface convex shape continuous with the outer periphery of the fixed cap 35 (the rotation direction of the motor rotation shaft 12) is formed.
It may be.

In the above embodiment, the fixing cap 35 is formed separately from the third extension 36 forming the commutator base. However, the present invention is not limited to this. May be integrally molded. This reduces the number of parts and contributes to a reduction in the cost of the bearing device. In addition, since the bearing 24 and the commutator main body 38 can be closer to each other in the axial direction, the length in the axial direction can be shortened, and the motor 1 can be downsized. Further, the third extension 36 and the fixing cap 3
By molding resin 5 with resin, molding is facilitated, and the motor 1 is reduced in weight.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a motor according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an armature of a motor.

FIG. 3 is a sectional view showing an armature of a motor.

FIG. 4 is a sectional view showing a bearing structure of the motor.

FIG. 5 is a sectional view showing a bearing structure of the motor according to the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Motor, 12 ... Motor rotating shaft, 20 ... Motor case, 22, 24 ... Bearing (oil-containing bearing), 22a, 24a ...
Bearing side surface (thrust receiving surface), 35: fixed cap (rotating body and fixed member), 35b: groove (outer peripheral groove), 35c ...
Outer peripheral wall, 36... Third extension (commutator base), 38 a.
Commutator piece.

Claims (4)

[Claims] A motor rotating shaft that rotates in a motor case, a rotating body provided on the motor rotating shaft and integrally rotating with the motor rotating shaft, and a motor that is provided in the motor case and rotatably supports the motor rotating shaft. And an oil-impregnated bearing having a thrust receiving surface slidable with the rotating body in the axial direction of the motor rotating shaft; and oil provided along an outer circumferential surface of the rotating body in a rotating direction, and leaking from the oil-impregnated bearing. And a peripheral wall for preventing movement of the motor. 2. A commutator base fixed to the rotating shaft, and a plurality of commutator pieces fixed to the outer periphery of the commutator base at predetermined intervals, and the rotating body is connected to the commutator base. The bearing device for a motor according to claim 1, wherein the bearing device is formed integrally with the motor. 3. A commutator base fixed to the rotating shaft, and a plurality of commutator pieces provided at a predetermined interval on an outer periphery of the commutator base, wherein the rotating body includes the commutator. The motor bearing device according to claim 1, wherein the fixing device is attached to the base and forms a fixing member for fixing the commutator piece to the commutator base. 4. The motor bearing device according to claim 1, wherein the rotating body is formed of resin.