JP3155665B2 - Motor thrust bearing mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thrust bearing mechanism for a motor.

[0002]

2. Description of the Related Art A thrust bearing mechanism is used to support a rotating shaft of a motor in a thrust direction. FIG. 3 and FIG. 4 show examples of such a conventional motor thrust bearing mechanism. 3 and 4, a cylindrical bearing holder 2 is shown.
A sintered oil-impregnated bearing 22 is press-fitted and fixed to the inner surface of the peripheral wall 3. The sintered oil-impregnated bearing 22 is ring-shaped and has countless porosity, and the porous is impregnated with bearing oil.

[0003] A ring-shaped washer 24 is attached to the opening of the bearing holder 23 above the sintered oil-impregnated bearing 22. A gap is formed between the lower surface of the washer 24 and the upper end surface of the sintered oil-impregnated bearing 22, and the upper end surface of the washer 24 is substantially at the same height as the upper end surface of the peripheral wall of the bearing holder 23. A film-like sliding member 27 made of resin or the like is attached to the upper surface of the washer 24.

A thrust receiving member 26 having a hole in the center is mounted on a sliding member 27 of the washer 24. Since the thrust receiving member 26 slides on the sliding member 27 of the washer 24, it is formed of a resin such as nylon or Teflon with little friction or wear, or a metal body whose surface is coated with a resin for low friction. ing. A fan-shaped projection 26a is formed on the upper end surface of the thrust receiving member 26.

[0005] A single rotating shaft 21 is inserted through holes in the center of the thrust receiving member 26, the washer 24, and the sintered oil-impregnated bearing 22. The rotating shaft 21 is rotatably supported in a radial direction by a sintered oil-impregnated bearing 22. When the rotating shaft 21 rotates, the bearing oil impregnated in the sintered oil-impregnated bearing 22 is sucked into the central hole where the rotating shaft 21 is inserted, and the rotating shaft 21 is smoothly driven to rotate.

A groove 21a is formed on the outer peripheral surface of the rotary shaft 21 above the washer 24, and a hook 25 is attached to the groove 21a. The hook 25 has claw portions 25a extending toward the inner diameter side at three positions, that is, at both ends and a center portion. The tip of each claw portion 25a is fitted into the groove portion 21a of the rotary shaft 21 and the groove portion is formed. The hook 25 is substantially integrally attached to the rotating shaft 21 by sandwiching the 21 a from the periphery. Further, the outer shape of the hook 25 is substantially circular, but is partially cut out in a fan shape. The hook 25 is a projection 26a of the thrust receiving member 26.
Are mounted on the upper end surface except for the
And the fan-shaped projection 26a is fitted into the fan-shaped notch.

The hook 25 is supported by a thrust receiving member 26, and the thrust receiving member 26 is supported in contact with the washer 24. For this reason, the rotation shaft 21
A load in the thrust direction is supported by a thrust bearing including the thrust receiving member 26 and the washer 24.

In the above-described motor thrust bearing mechanism, when the rotating shaft 21 rotates, the latch 25 attached to the groove 21a also rotates integrally. As the hook 25 rotates, the claw portions 25a at both ends of the hook 25,
Since the side surface of one claw portion 25a of the 25a contacts the side surface of the projection 26a of the thrust receiving member 26, the thrust receiving member 26 rotates on the sliding member 27 of the washer 24.

[0009]

According to the conventional motor thrust bearing mechanism, the thrust receiving member 2 of the washer 24 is provided.
The sliding member 27 is adhered to the surface on which the end face of 6 slides to improve the slidability when the rotating shaft rotates at high speed. However, by attaching the sliding member 27 to the end face of the washer 24, the number of processing steps is increased, which has caused a rise in cost.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a low-cost motor thrust bearing mechanism which has good slidability at high speed rotation and is low in cost. With the goal.

[0011]

In order to achieve the above object, the present invention provides a rotating shaft having a rotor fixed to one end,
A sintered oil-impregnated bearing that rotatably supports the rotating shaft, a bearing holder that holds the sintered oil-impregnated bearing, a washer disposed at an end of the bearing holder, and a groove that is provided on an outer peripheral surface of the rotating shaft. And a hook that rotates with the rotating shaft, and is attached to the outer circumference of the rotating shaft and fitted to the above-mentioned hook,
An end face includes a thrust receiving member that slides on the washer,
In a thrust bearing mechanism of a motor that supports a rotating shaft with a hook, a thrust receiving member, and a washer, a minute gap is provided between the thrust receiving member and the rotating shaft, and between the washer and the rotating shaft.
The small gap between the thrust receiving member and the rotating shaft is
The step is provided on the inner peripheral surface on the opening side of the bearing holder, and the inner end surface of the sintered oil-impregnated bearing is brought into contact with this step, and the sintered oil-impregnated bearing is provided. A washer is brought into contact with the outer end face of the bearing, and the bearing oil of the sintered oil-impregnated bearing is interposed between the washer and the thrust receiving member to bring the washer into contact with the thrust receiving member.

[0012]

The bearing oil of the sintered oil-impregnated bearing is sucked up by the minute gap between the washer and the rotating shaft. The sucked-up bearing oil is interposed between the washer and the thrust receiving member constituting the thrust bearing, and the frictional resistance between the washer and the thrust receiving member is reduced.
The rotating shaft rotates smoothly.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a thrust bearing mechanism for a motor according to the present invention will be described below with reference to the drawings. In FIG. 1, a step 3a is formed on the inner surface of the peripheral wall on the opening end side of the cylindrical bearing holder 3. The sintered oil-impregnated bearing 2 is press-fitted into the inner surface of the peripheral wall of the bearing holder 3, and the lower end surface of the sintered oil-impregnated bearing 2 is in contact with a step 3 a on the inner surface of the peripheral wall of the bearing holder 3. The sintered oil-impregnated bearing 2 is ring-shaped and has countless porosity, and the porous is impregnated with bearing oil.

Bearing holder 3 above sintered oil-impregnated bearing 2
The inner peripheral edge of the opening is cut off stepwise, and a washer 4 is attached to the cut off portion. The washer 4 is a ring-shaped plate made of stainless steel or the like, and its lower surface is in contact with the upper end surface of the sintered oil-impregnated bearing 2.

On the upper surface of the washer 4, a thrust receiving member 6 having a hole at the center is slidably mounted on the washer 4.
A fan-shaped protrusion 6a is formed on the upper end surface of the thrust receiving member 6 as in the above-described conventional example.

One rotary shaft 1 is inserted through the thrust receiving member 6, the washer 4, and the central hole of the sintered oil-impregnated bearing 2. Between the washer 4 and the rotating shaft 1 and between the thrust receiving member 6 and the rotating shaft 1
There is a small gap between each , thrust
The minute gap between the receiving member 6 and the rotating shaft 1 is
1 are formed smaller than the minute gap . The rotating shaft 1 is rotatably supported in a radial direction by a sintered oil-impregnated bearing 2. When the rotating shaft 1 rotates, the bearing oil impregnated in the sintered oil-impregnated bearing 2 is sucked out, and the inside of the central hole through which the rotating shaft 1 is inserted is filled with the bearing oil. It is driven to rotate smoothly.

A groove 1a is formed on the outer peripheral surface of the rotary shaft 1 above the washer 4, and a hook 5 is attached to the groove 1a. The hook 5 has the same shape as that of the conventional example shown in FIGS. 3 and 4, and has claw portions (not shown) extending toward the inner diameter side at three positions at both ends and a center portion. Is fitted into the groove 1a of the rotating shaft 1 and the groove 1a is sandwiched from the periphery, so that the hook 5 is fixed to the rotating shaft 1. Further, although the outer shape of the hook 5 is substantially circular, it is partially cut out in a fan shape. The lower surface of such a hook 5 is placed on the upper end surface of the thrust receiving member 6 excluding the projection 6a, and the projection 6a of the thrust receiving member 6 is cut out in a sector shape of the hook 5. Is fitted with

The latch 5 attached to the rotating shaft 1 is supported by a thrust receiving member 6, and the thrust receiving member 6 is supported in contact with the washer 4. Therefore, the rotating shaft 1
The load in the thrust direction is supported by a thrust bearing composed of each of the latching tool 5, the thrust receiving member 6, and the washer 4. A rotor including a rotor case and the like are integrally provided on the rotating shaft 1, and a stator including a stator core, a driving coil, and the like are fixed to the outer peripheral side of the bearing holder 3, and the rotor and the stator constitute a motor.

According to the above-described thrust bearing mechanism of the motor, when the rotating shaft 1 is driven to rotate, the outer peripheral surface of the rotating shaft 1 is in sliding contact with the inner peripheral surface of the sintered oil-impregnated bearing 2. The impregnated bearing oil is sucked out to the inner peripheral surface of the sintered oil-impregnated bearing 2. As shown in FIG. 2, the bearing oil B sucked into the inner peripheral surface of the sintered oil-impregnated bearing 2 is moved between the washer 4 and the rotating shaft 1 and between the washer 4 and the rotating shaft 1 by a capillary phenomenon. It is sucked into the minute gap provided between them.

The bearing oil B sucked into the minute gap rises to the upper end of the washer 4. The thrust receiving member 6 is placed on the upper end surface of the washer 4, but the washer 4 and the thrust receiving member 6 are not in close contact with each other, and a minute gap is generated. Therefore,
It is sucked into the minute gap between the washer 4 and the rotating shaft 1, and the washer 4
Bearing oil B which has risen to the upper end of the thrust enters the minute gap between the washer 4 and the thrust receiving member 6. When the bearing oil B infiltrates between the washer 4 and the thrust receiving member 6, the bearing oil B
Plays a role of lubricating oil, so that when the thrust receiving member 6 slides on the washer 4, the frictional resistance of the thrust receiving member 6 to the washer 4 can be reduced, and the slidability is dramatically improved. be able to.

In addition, friction resistance can be suppressed without adding a new sliding member or the like to the washer 4 and slidability can be improved, so that component costs can be reduced, which contributes to cost reduction. can do.

[0022]

According to the present invention, there are minute gaps between the thrust receiving member and the rotating shaft, and between the washer and the rotating shaft, and a step portion is formed on the inner peripheral surface on the opening side of the bearing holder. Since the inner end surface of the sintered oil-impregnated bearing is abutted by the stepped portion and the washer abuts on the outer end surface of the sintered oil-impregnated bearing, between the thrust receiving member and the rotating shaft, and between the washer The bearing oil of the sintered oil-impregnated bearing can be sucked up in the minute gap between the shaft and the rotating shaft, and the sucked-up bearing oil penetrates between the washer and the thrust receiving member to reduce the frictional resistance between them. Therefore, a thrust bearing mechanism of a motor having good slidability can be obtained without newly adding members such as sliding members, and it is possible to contribute to cost reduction.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a thrust bearing mechanism for a motor according to the present invention.

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

FIG. 3 is a perspective view showing an example of a conventional thrust bearing mechanism of a motor.

FIG. 4 is a sectional view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotating shaft 1a Groove part 2 Sintered oil-impregnated bearing 3 Bearing holder 3a Step part 4 Washer 5 Hook 6 Thrust receiving member

Claims (1)

(57) [Claims] A rotating shaft having a rotor fixed to one end thereof; a sintered oil-impregnated bearing rotatably supporting the rotating shaft; a bearing holder for holding the sintered oil-impregnated bearing; and an end disposed at the end of the bearing holder. A washer provided, a latch that engages with a groove provided on the outer peripheral surface of the rotary shaft and rotates together with the rotary shaft, and is attached to the outer periphery of the rotary shaft and fitted to the latch. A thrust receiving member having an end surface sliding on the washer, wherein the latch, the thrust receiving member, and the washer include:
In the thrust bearing mechanism for a motor supporting the rotating shaft, a minute gap between the thrust receiving member and the rotating shaft is formed to be smaller than a minute gap between the washer and the rotating shaft. A step is provided on the inner peripheral surface on the opening side, and the inner end face of the sintered oil-impregnated bearing abuts on the step, and the washer abuts on the outer end face of the sintered oil-impregnated bearing. A bearing mechanism wherein the bearing oil of the sintered oil-impregnated bearing is interposed between the washer and the thrust receiving member, and the washer and the thrust receiving member are in contact with each other.