JP2000014085A - Cooling fan fitting device for electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely fix a device and to provide a structure with easy assembly by installing projections in the rotor shaft insertion part of a cooling fan formed of a resin member whose flexibility and thermal expansion coefficient are high, installing recessed parts into which the projections are inserted in the rotor shaft of an electric motor, thermally expanding the cooling fan in a high temperature tank and inserting it into the rotor shaft. SOLUTION: More than one projections (a) are installed in the inner diameter of the rotor shaft insertion part of a cooling fan formed of a resin member having high flexibility and thermal expansion coefficient. Then, recessed parts into which the projections (a) of the cooling fan are inserted are provided in the rotor shaft of an electric motor. The inner diameter D1 of the rotor insertion part of the cooling fan is made to be smaller than the outer diameter of the rotor shaft of the electric motor. The cooling fan is put in a high temperature tank, it is thermally expanded and it is inserted into the rotor shaft. Thus, a fixing method with the high certainty of stopping revolution and fall-off can be provided and structure with easy automatic assembly can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor requiring a fan for cooling by utilizing the rotational force of the electric motor, and more particularly to a cooling fan formed of a resin material having a high elastic force and a high coefficient of thermal expansion. One or more (plural) protrusions are installed in the inner diameter part (rotor shaft insertion part), and the rotor shaft part is provided with a recess in which the protrusion set in the fan inner diameter can be fitted, and placed. A cooling fan mounting device for electric motors, in which the fan is placed in a high-temperature bath or the like and the inner diameter of the fan is expanded and inserted and fixed to the rotor shaft, thereby facilitating the mounting of the cooling fan and enabling automation of assembly. is there.

[0002]

2. Description of the Related Art Conventionally, as a method of fixing a motor rotor shaft and a cooling fan, a screw hole is provided in a shaft insertion portion of the cooling fan, a screw is penetrated to the rotor shaft and fixed, or a shaft insertion portion of the cooling fan is fixed. Since the outer diameter portion is tightened and fixed by the spring pressure of the shaft C-ring or the like, the fixing method lacks certainty, and the difficulty in assembling makes automatic assembly difficult and costly.

[0003]

As described in the prior art, a method for cooling an electric motor which requires the electric motor to be cooled by a cooling fan is an apparatus for mounting a cooling fan made of resin or the like on a rotor shaft. Since the fixing method is such that the screw is fixed to the rotor shaft or tightened by the pressure of a spring such as a shaft C ring, it cannot be completely fixed or has difficulty in assembling, which makes automatic assembling difficult.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a cooling fan made of resin or the like having a high elastic force and a high coefficient of thermal expansion. In addition, the rotor shaft is provided with a concave portion in which the convex portion provided on the inner diameter of the cooling fan is inserted, and the inner diameter of the cooling fan is set smaller than the outer diameter of the rotor shaft.

Next, when the cooling fan is inserted into the rotor shaft, the cooling fan is placed in a high-temperature bath and the inner diameter of the fan is thermally expanded. Can be inserted smoothly.

[0006] Therefore, the cooling fan that has been thermally expanded returns to normal temperature, so that the inner diameter of the cooling fan becomes smaller than the outer diameter of the rotor shaft, and the cooling fan is tightened and fixed. Furthermore, the rotation stopper and the stopper can be more securely fixed by inserting and inserting the convex part of the cooling fan inside diameter into the concave part of the rotor shaft, which has been installed in advance, and the assembling has been facilitated, so that the automatic assembling is facilitated. Is what makes it possible.

[0007]

[Means for Solving the Problems] In recent years, resin-based cooling fans have been widely used for electric motors. However, the method of fixing the rotor to the fixed shaft includes a screw tightening method, a shaft C ring, or the like. Because of the method of fixing by spring pressure, it was not possible to fix securely, or there was a difficulty in assembling, and it was difficult to assemble automatically, so to solve these problems, a resin material with high elasticity and thermal expansion coefficient One or more (plural) protrusions are provided at the inner diameter of the cooling fan, that is, at the rotor shaft insertion portion, and the rotor shaft is provided with a concave portion at which the protrusion provided at the fan inner diameter enters.

Further, the inner diameter of the cooling fan inserted into the rotor shaft is made smaller than the outer diameter of the rotor shaft. Next, when inserting the cooling fan into the rotor shaft, put the cooling fan in a high-temperature bath and allow the cooling fan to expand smoothly until the inner diameter of the cooling fan becomes larger than the outer diameter of the rotor shaft. It can be inserted.

Therefore, when the cooling fan that has been thermally expanded returns to the normal temperature after being inserted into the rotor shaft, the inner diameter of the cooling fan becomes smaller than the outer diameter of the rotor shaft, so that the cooling fan can be tightened and fixed. Furthermore,
In order to secure rotation and retainment, the convex part installed on the inner diameter of the cooling fan is inserted into the concave part installed on the rotor shaft, so that it can be fixed more securely, and assembly is easy and automatic assembly is possible. Is what you do.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings.

An object of the present invention is to automatically assemble an electric motor using a cooling fan formed of resin or the like having a high elastic force and a high coefficient of thermal expansion on a rotor shaft for the purpose of cooling by utilizing the rotational force of the electric motor. It is a mounting device for performing.

FIGS. 1A and 1B show a cooling fan of a motor mounting device according to the present invention. That is, one or more (a plurality of) convex portions a are installed in the inner diameter of the cooling fan, and FIGS.
The rotor shaft 2 is provided with a concave portion b in which the convex portion of the cooling fan is inserted.

Next, as shown in FIG. 3, the inside diameter D1 of the cooling fan is made smaller than the outside diameter D2 of the rotor shaft (D1 ≦ D2), and the cooling fan is placed in a high-temperature bath so that the inside diameter of the fan is made smaller than the outside diameter of the rotor shaft. It is made larger by expansion (D1 ≧ D2) and inserted into the rotor shaft.

Therefore, when the thermally expanded cooling fan returns to normal temperature after being inserted into the rotor shaft, the inner diameter D of the cooling fan is reduced.
1 is smaller than the rotor shaft D2 (D1 ≦ D2), so that it is tightened and fixed. Furthermore, by inserting the convex portion provided on the inner diameter of the cooling fan into the concave portion provided on the rotor shaft, the rotation stopper and the stopper are more reliably fixed.

In addition, since a system for stacking parts indispensable for automatic assembly has been established, automatic assembly can be facilitated and cost can be reduced.

[0016]

According to the present invention, there are provided: Easy assembly and automatic assembly. 2. With ease of assembly,
Cost reduction can be measured. 3. The mounting and fixing of the cooling fan became reliable, and safety was established.

[Brief description of the drawings]

FIGS. 1A and 1B are a front view and a cross-sectional view of a main part of a cooling fan for an electric motor according to the present invention.

2A and 2B are a front view and a sectional view of a main part of a rotor shaft according to the present invention.

FIG. 3 is a partial sectional view of an electric motor cooling fan mounting device of the electric motor of the present invention.

FIG. 4 is a sectional view of an electric motor cooling fan mounting device of the electric motor of the present invention.

FIG. 5 is a cross-sectional view of a main part of a conventional motor, in which a cooling fan for fixing a motor spring is mounted.

FIG. 6 is a cross-sectional view of a main part of a conventional motor in which a cooling fan for fixing a motor screw is fixed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cooling fan for motors of this invention, 2 ... Rotor, 3 ... Rotor shaft, 4 ... Stator, 5 ... Non-load side end bracket,
6 ... Load side end bracket, 7 ... Ball bearing,
8. Through bolts.

Claims (1)

[Claims] 1. A cooling fan formed of a resin or the like having a high elasticity and a high thermal expansion on a rotor shaft for cooling by utilizing the rotating force of an electric motor. That is, one or more (plural) protrusions are provided on the inner diameter of the cooling fan, and then a recess which can be inserted and inserted with the protrusion previously installed on the inner diameter of the cooling fan is provided on the rotor shaft on which the cooling fan is mounted. By placing the cooling fan in a high-temperature bath, etc., expanding the cooling fan thermally, expanding the inner diameter of the fan, inserting it into the rotor shaft, and inserting it into the rotor shaft. A cooling fan mounting device for an electric motor, characterized in that the device is inserted into a concave portion while being warmed up and fixed securely and simultaneously with a detent and a retaining member.