JPS62254643A - Motor - Google Patents

Abstract

PURPOSE:To make assembling easy and to provide dust-proof and water-proof effects, by a method wherein an air ventilating hole is formed from a recess of a bearing housing towards a rotor. CONSTITUTION: An end bracket 2 is fixed to a stator 1, and a concave bearing housing 3 is formed on the end bracket 2 and a ball bearing 5 is fitted thereto so as to support a rotor shaft 4. An air ventilating hole 8a is formed from a recess 6 of the bearing housing 3 towards a rotor 7. The ball bearing 5 is fitted to the bearing housing 3, and in turn when the rotor shaft 4 is fitted to the ball bearing 5 and assembling is performed, air in the recess 6 is not compressed but exhausted through the air ventilating hole 8a, thereby the assembling becomes easy. Since an exhaust hole leading to oudside is not necessary in the end bracket 2, dust-proof and water-proof effects can be easily obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to the structure of an electric motor in which a bearing portion and the like are sealed.

``Prior Art'' Depending on conditions such as the environment in which an electric motor is used, the internal charging part may be enclosed in a frame to seal it.

Furthermore, even if the entire bearing is not sealed, only the bearing portion may be sealed, as water entering the bearing will cause problems such as rust.

When assembling the bearing, when assembling the bearing, the air pushed by the shaft does not escape when the shaft is fitted into the part of the bearing that is to be fitted into the bearing. Please help me escape through the gaps. I was assembling it.

1 However, in mass production, such a situation results in a time-consuming assembly and is a major obstacle to reducing assembly time, especially when it is desired to adjust the axial play of the rotor shaft, that is, the end play. was.

This kind of problem does not occur in metal type bearings equipped with an oil core because air flows through the gap in the oil core in the axial direction of the metal. This was a unique problem when using a metal type bearing that does not have an oil core.

Even in the case of ball bearings, if there is a gap between the balls in the front and back in the axial direction, this will not cause any problems, but electric motors that are generally configured to be dust-proof or waterproof are of the type where the bearing is also sealed in the axial direction. However, this was not convenient in terms of durability, and often caused problems in fitting the shaft.

[Problems to be solved by the invention] The present invention has been made in view of these circumstances,
It is an object of the present invention to provide an electric motor configured so that a bearing does not become an obstacle to assembly when configured in a closed type.

"Means for Solving the Problem" The present invention solves the problem by forming a vent from the concave portion of the bearing housing to the rotor side.

"Function" A vent is formed from the concave part of the bearing housing that holds the bearing to the rotor side, so even if the rotor shaft is fitted and the air in the concave part is compressed, the air can be easily vented and the shaft can be fitted. No damage will occur if the

Further, since the vent is formed on the rotor side of the bearing housing, there is no ventilation to the outside of the motor, and there is no problem in forming a dustproof and waterproof structure.

"Example" The present invention will be explained based on the example shown in the drawings.
FIG. 1 is a longitudinal cross-sectional view of a main part of an electric motor according to one embodiment of the present invention, and FIGS. 2 and 3 are longitudinal cross-sectional views of main parts according to other embodiments, respectively.

In FIG. 1, the electric motor is equipped with an end bracket 2 fixed to a stator 1, and a concave bearing housing 3 is formed in the end bracket 2. A ball bearing 5 supporting the is fitted.

A vent hole 8a is formed from the concave portion 6 of the bearing housing 3 to the rotor 7 side.

Further, the end bracket 2 is made of a drawn steel plate and constitutes a housing, and is constructed as a dust-proof and water-discharging type that isolates the stator 1 and rotor 7 housed inside from the outside.

In FIG. 2, the vent 8b is formed by forming a groove in a portion of the bearing housing 3 that comes into contact with the ball bearing 5 when the end bracket 2 is drawn.

The vent hole 8b formed by the groove may be formed by machining after drawing the end bracket 2, and it is sufficient if the concave portion 6 and the inside of the end bracket 2 are communicated with each other.

In FIG. 3, the vent 8G is formed by forming the rotor shaft 4 into a hollow part.

To make this hollow, drill a hole in the rotor shaft 4 from the axial direction,
This can be easily formed by drilling a hole perpendicular to the axis so that the concave portion 6 and the inside of the end bracket 2 are communicated with each other.

Alternatively, it can be easily formed by using a pipe material for the rotor shaft 4 from the beginning and drilling holes near the rotor 8 so as to communicate with the inside of the end bracket 2.

In such a configuration, the electric motor has a steel plate attached to the end bracket 2 and the concave portion 6 for forming the bearing housing 3.
, and is assembled by drawing and fixing to the stator 1.

Then, the ball bearing 5 is fitted into the bearing housing 3, and then the rotor shaft 4 is fitted into the ball bearing 5.

At this time, the rotor shaft 4 compresses the air inside the concave portion 6 through the fitting portion of the ball bearing 5. According to the embodiment shown in FIG. A vent hole 8 formed by a groove formed in the fitting part with the bearing 5
The air in the concave portion 6 is exhausted without being compressed through a, thereby causing no trouble to the assembly.

The vent hole 8a formed by such a groove can be easily formed by forming an axial groove at the end of the rotor shaft 4.
Moreover, this groove does not interfere with the construction of the electric motor, such as the relationship with the pole bearing 5 and the relationship with the rotor 7, which is convenient.

Furthermore, the vent hole 8a formed by a groove can be easily formed at the end of the rotor shaft 4 by cutting the groove with a machine equipped with a rotating blade.

In addition, in the case of forming the vent hole 8b by a groove in the bearing housing 3 shown in FIG. 2, which is another embodiment, it may be formed and manufactured at the same time when the end bracket 2 is formed by squeezing the steel plate. If it is difficult to form a small groove due to the thickness of the steel plate and the diameter of the bearing housing 3, it is possible to form the groove by a machine such as drawing.

Since the vents Ba and Bb formed by such grooves are sufficient as long as they can exhaust the air compressed by the rotor shaft 4,
It is sufficient to have an extremely small cross-sectional area, and it cannot be said that machining is difficult.

Of course, even if the vents 8a and 8b are manually scratched, it is possible to construct the vents 8a and 8b with considerable effects.

Furthermore, in the embodiment shown in FIG.
It is hollow, and can be easily formed by drilling the shaft 4 in the axial direction and at right angles to the shaft.

Of course, if the rotor 7 is attached to the hollow shaft H from the beginning and constructed, the construction can be easily performed by drilling holes perpendicular to the shaft.

"Effects of the Invention" According to the present invention, when an electric motor is constructed in a sealed type, the bearing can be constructed so that it does not become an obstacle to assembly.In particular, it is necessary to adjust the end play of the rotor shaft, If the rotor shaft needs to be fitted and removed from the ball bearing several times, there will be no assembly failure, and there is no need to form a hole in the end bracket that leads to the outside, making it dustproof and waterproof. type electric motor can be easily configured.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a main part of an electric motor according to one embodiment of the present invention, and FIGS. 2 and 3 are longitudinal cross-sectional views of main parts according to other embodiments, respectively. 2... End bracket, 3... Bearing housing, 4... Rotor shaft, 5... Ball bearing,
6... Concave portion, 8a, 8b, 8C... Ventilation port.

Claims (4)

[Claims] (1) An end bracket fixed to the stator is provided, and a concave bearing housing is formed in the end bracket,
An electric motor configured by fitting a ball bearing that supports a rotor shaft into a bearing housing, characterized in that a vent is formed from a concave portion of the bearing housing to the rotor side. (2) The electric motor according to claim 1, wherein a groove is formed in a portion of the rotor shaft where the ball bearing fits into the rotor shaft to serve as a vent. (3) The electric motor according to claim 1, wherein the rotor shaft is formed of a hollow member to serve as a vent. (4) The electric motor according to claim 1, wherein a groove is formed in a portion of the concave portion that contacts the ball bearing to serve as a vent.