JP2001208064A - Bearing structure of rotating electrical machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing structure of a rotating electrical machinery wherein, while a pressure in the enclosed region formed by a blind type concave 26 shaped at the bottom of an end bracket 2 and a motor shaft 3 is subject to fluctuation due to a thrust displacement of the motor shaft 3, a lubricating oil impregnated in a ball metal is prevented from leaking to the exterior of the ball metal due to the caused pressure fluctuation. SOLUTION: In the internal circumference of the concave 2b against which the ball metal 10 abuts, an adjustment groove 2d is formed to evade the pressure fluctuation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of bearing structures for rotating electric machines such as electric motors.

[0002]

2. Description of the Related Art Generally, in this type of rotating electric machine, an armature shaft is provided with a housing (for example, a casing and an end bracket fixed to seal the casing opening) through an oil-impregnated ball metal (oil-impregnated bearing). ) Are rotatably supported. In such a pivot structure, a blind concave portion formed on the bottom surface of the housing, and a ball metal fitted into the concave portion,
In some cases, a closed space is formed by an armature shaft penetrating the ball metal.

[0003]

In such a conventional motor, an example in which the rotating electric machine is a fan motor will now be described. In the case where the motor shaft is slightly movable in the thrust direction, The motor shaft (armature shaft) is thrust-moved in a direction to enlarge the volume of the closed space by the fan thrust at the time of driving the motor, so that the closed space is in a negative pressure state, and impregnated into the ball metal in response to this. When lubricating oil or lubricating oil for lubricating between the ball metal and the motor shaft flows into the closed space, the motor drive is turned off and the motor shaft returns to its original position. In this state, the lubricating oil escapes to the inside of the housing. By repeating this phenomenon, not only the lubricating oil impregnated in the ball metal is consumed at an early stage, but also in the case where an oil-impregnated felt is arranged around the outer periphery of the ball metal, a large amount of lubricating oil contained in the felt is used. The oil escapes to the inside of the housing, and the escaped lubricating oil travels along the motor shaft to reach the commutator, causing problems such as abnormal wear of the commutator and brush and impaired electrical contact. Assumed, there is a problem to be solved by the present invention.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve these problems in view of the above-mentioned circumstances, and has a blind hole formed in a bottom surface of a cylinder of a housing. A rotary electric machine in which an oil-impregnated ball metal is fixed and the end of a penetrating armature shaft is rotatably supported by the ball metal, wherein the rotary electric machine is formed by the concave hole, the ball metal, and the armature shaft. A pressure adjusting means for adjusting the pressure in the closed space to be equal to the pressure in the housing. In this case, the pressure adjusting means may be characterized in that the pressure adjusting means is an adjusting groove formed in the inner peripheral surface portion with which the ball metal of the concave hole contacts. The pressure adjusting means may be an adjusting groove formed on the outer peripheral surface of the ball metal in contact with the concave hole, or an adjusting hole formed to penetrate the ball metal. Furthermore, the pressure adjusting means can be characterized in that it is an adjusting hole penetratingly penetrated in the armature shaft supported by the ball metal. The present invention makes it possible to adjust the pressure in the closed space when the armature shaft moves in the thrust direction so as to be the same as the pressure in the housing without impairing the waterproofness, and to adjust the ball metal. To reduce the consumption of the lubricating oil impregnated.

[0005]

Next, an embodiment of the present invention will be described with reference to the drawings. In the figure, reference numeral 1 denotes a casing of a fan motor, and the casing 1 forms a motor housing by covering an opening with an end bracket 2, but in this embodiment, as will be described later, The present invention is applied to the bracket 2.

Reference numeral 3 denotes a motor shaft whose ends are rotatably supported on the casing 1 and the end bracket 2, respectively. The fan 4 is integrally fixed via a bolt 4a. In the figure, 5 is a casing 1
, A rotor fixed to the motor shaft 3, a commutator 7, and a brush 8 slidably contacting the commutator 7, all of which are conventional. .

Each end of the motor shaft 3 is connected to a cylinder bottom 1a of the casing 1 through oil-impregnated ball metals 9, 10.
The end bracket 2 is rotatably supported on the cylindrical bottom surface 2a. That is, concave holes 1b, 2b are formed in the center of each cylinder bottom surface 1a, 2a.
Is stopped in a fixed state in which one end thereof is pressed into the concave holes 1b, 2b via the metal holders 11 supported on the cylindrical bottom surfaces 1a, 2a in a state of being fitted into the concave holes 1b, 2b. Is to be worn. A ring-shaped felt 12 impregnated with lubricating oil is disposed on the outer peripheral surfaces of the ball metals 9 and 10 fixed in this manner, so that lubricating oil is supplied to the ball metals 9 and 10. Is considered.

[0008] Of the ends of the motor shaft 3 which are supported by the ball metals 9 and 10, a through hole 1c for penetrating the motor shaft 3 is formed in the cylindrical bottom surface 1a on the side where the fan 4 is fixed. Therefore, the problem of motivation of the present invention does not occur, but the problem of motivation of the present invention occurs because the bottom surface 2a of the end bracket cylinder is blind. do. In other words, the end of the motor shaft 3 on the end bracket 2 side is the cylindrical bottom surface 2a.
The blind hole 2b which is blind is formed at the center of the hole, and a ring-shaped groove 2c is further formed on the outer diameter side of the hole 2b. The ball metal 10 whose one end is inserted into the concave hole 2b is inserted into the concave groove 2b.
c, the metal holder 11 is inserted into the groove 2c so as to lock the outer peripheral edge thereof.
a closed space S is formed by the blind concave hole 2b, the ball metal 10 and the motor shaft 3 by pressing the ball metal 1 in the concave hole 2b.
An adjustment groove 2d for adjusting the pressure in the closed space S so as to be equal to the pressure in the motor housing formed by the casing 1 and the end bracket 2 is formed on the inner peripheral surface with which the zero abuts. Have been. In other words, the adjustment groove 2d is formed so as to extend from the closed space S beyond the contact surface portion of the ball metal 10 in the axial direction. Incidentally, in this embodiment, three adjusting grooves 2d are formed at intervals of 120 ° C. in the circumferential direction, but are adjusted so that the pressure in the closed space S becomes the same as the pressure inside the casing. If so, the number, size, etc. are not specified.

When the motor shaft 3 moves axially in response to the drive-stop of the motor or the like, the concave hole 2b formed in the cylindrical bottom surface 2a of the end bracket 2, the ball metal 10 and motor shaft 3
The volume of the closed space S formed between the two increases and decreases, and the pressure with the closed space tends to change. This pressure fluctuation is caused by the adjustment of the formation on the inner peripheral surface of the concave hole 2b. Groove 2
The pressure d is adjusted to be equal to the pressure in the motor housing. As a result, the pressure in the closed space S becomes the same as the pressure in the motor housing irrespective of the thrust movement of the motor shaft 3, and the differential pressure is reduced as in the prior art.
The pressure is not adjusted by acting on itself or the gap between the ball metal 10 and the motor shaft 3, and the lubricating oil impregnated in the ball metal 10 and the lubricating oil in the gap are removed from the closed space S. It is possible to prevent the problem of flowing out to the motor housing side or the motor housing side while maintaining waterproofness, and to avoid early consumption of the lubricating oil to be impregnated.

[0010] The present invention, as in the above embodiment,
It is needless to say that the pressure adjusting means is not limited to a groove formed on the inner peripheral surface of the concave hole. An adjustment groove 10a formed in the motor shaft 3 or an adjustment hole 10b formed in the ball metal 10 so as to penetrate the ball metal 10. Further, as in another embodiment shown in FIG. The adjusting hole 3a can be formed into a shape. And the adjustment hole 3a opened in this case
Is required to be formed symmetrically so as not to impair the rotational balance.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a fan motor.

2A is a front view of an end bracket, and FIG. 2B is a cross-sectional side view of the end bracket.

FIG. 3 is an enlarged view of an adjustment groove portion of the end bracket.

FIG. 4 is an enlarged side view of a concave hole portion of the end bracket.

FIGS. 5A and 5B are perspective views of a ball metal showing another embodiment of the present invention.

FIG. 6 is a front view of a main part of a motor shaft showing still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 End bracket 2b Concave hole 2d Adjustment groove 3 Motor shaft 10 Ball metal 11 Metal holder 12 Felt

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Atsushi Shimura 1-268, Hirosawa-cho, Kiryu-shi, Gunma F-term (reference) 3J011 CA01 JA02 KA02 LA01 MA01 3J012 AB20 BB02 DB02 FB04 5H605 BB05 BB09 CC02 CC04 CC05 EB06 EB13 EB16 EB20 EB26 EB28 GG05

Claims (4)

[Claims] 1. A rotating electric machine comprising: an oil-impregnated ball metal fixed to a blind concave hole formed in a bottom surface of a cylinder of a housing; and an end of a through armature shaft rotatably supported by the ball metal. A rotating electric machine provided with pressure adjusting means for adjusting the pressure in a closed space formed by the concave hole, the ball metal, and the armature shaft so as to be equal to the pressure in the housing. Bearing structure. 2. The bearing structure for a rotating electric machine according to claim 1, wherein said pressure adjusting means is an adjusting groove formed in an inner peripheral surface portion of said recessed hole, said ball metal abutting. 3. The rotating device according to claim 1, wherein the pressure adjusting means is an adjusting groove formed in an outer peripheral surface portion of the ball metal contacting the concave hole, or an adjusting hole formed to penetrate the ball metal. Electric motor bearing structure. 4. The bearing structure for a rotating electric machine according to claim 1, wherein the pressure adjusting means is an adjusting hole penetratingly formed in an armature shaft supported by the ball metal.