JPH0687728U - Electric motor - Google Patents

Abstract

(57) [Abstract] [Purpose] A screw hole 9 is provided in the shaft end 8 of the rotor shaft on the opposite side to reduce the temperature rise of the bearing of the electric motor. [Structure] An electric motor composed of a bracket 5 supporting a rotor 1 and a stator 3, and a shaft provided by a bearing 7 mounted on a bracket having a ventilation hole 10 at a shaft end portion of a rotor shaft on the counter load side. The shaft end 8 of the supported rotor shaft is provided with a screw hole 9 in the same direction as the rotation direction up to a position deeper than the width of the bearing. [Effect] The temperature rise value of the bearing 7 on the anti-load side is reduced only by forming the screw hole on the shaft end 8 of the rotor shaft on the anti-load side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to reducing the temperature rise of a bearing of an electric motor.

[0002]

[Prior art]

 FIG. 3 is a half sectional view of a conventional electric motor. A rotor 1 is built in a stator 3 having a stator winding 4 wound around it, and the stator 3 is sandwiched between two brackets 5 made of steel plate, and a load side bearing 6 is provided at both ends. The counter load side bearing 7 supports the rotor shaft 2.

[0003]

[Problems to be solved by the device]

 In this way, in the conventional type, winding, secondary resistance, bracket air holes, black paint, etc. can be considered as measures to reduce bearing temperature rise with the same motor size, but keep the temperature rise value within the standard. On the other hand, the requirements for miniaturization of electric motors were severe and conflicting conditions could not be satisfied together. The present invention has been made to solve such a conventional problem, and when the rotor shaft cannot be projected from the bracket, the shaft end of the rotor shaft on the non-load side is machined with a hole such as a screw hole to form a bearing. It is an object of the present invention to provide an electric motor capable of reducing the temperature rise.

[0004]

[Means for Solving the Problems]

 In order to solve this problem, in the electric motor according to the present invention, a screw hole in the same direction as the rotational direction of the electric motor is provided at the shaft end on the anti-load side of the rotor shaft.

[0005]

【work】

 In an electric motor that is composed of a bracket that supports the stator and rotor, a hole such as a screw hole is made in the rotor shaft end that rotatably supports the rotor shaft with bearings.

[0006]

【Example】

 Hereinafter, the configuration of the present invention will be specifically described based on the embodiments shown in the drawings. 1 and 2 are respectively a half sectional view of an electric motor and a front view of a main part of a rotor shaft, wherein 1 is a rotor having a rotor shaft 2 and 3 is a stator winding wound around a stator core. This is a stator having a wire 4. The rotor 1 and the stator 3 are sandwiched by two brackets 5, and a load side bearing 6 and an anti-load side bearing 7 that rotatably support the rotor shaft 2 are provided at the center of both ends of the bracket. Set up. In particular, in the case of a single-shaft motor, the anti-load side bearing 7 is inferior to the load side bearing in terms of heat release, the temperature rise value is high, and the life of the anti-load side bearing 7 is significantly shortened. Therefore, for the purpose of cooling the anti-load side bearing, the screw hole 9 in the same direction as the rotating direction of the rotor shaft 2 of the electric motor is inserted into the shaft end 8 of the anti-load side rotor shaft to a position deeper than the width of the bearing by a few millimeters. Is provided at the center of the shaft end 8. In this way, by providing the screw holes in the same direction as the rotor shaft, the heat inside the screw holes is released and the temperature rise of the bearing is reduced. For example, if the direction of rotation of the rotor shaft of the motor is clockwise when viewed from the load side, the screw hole should also be right-threaded. It should be noted that the effect of reducing the temperature rise instead of the screw hole at the shaft end is somewhat inferior, but the effect can be obtained by using only the hole. Moreover, the bracket having the ventilation hole 10 at the shaft end of the rotor shaft on the anti-load side is more effective. Further, it is needless to say that the hole machining of the shaft end of the rotor shaft is not limited to this and can be changed within a range not changing the gist.

[0007]

[Effect of device]

 With the above configuration, the following effects can be obtained as compared with the conventional example. To reduce the temperature rise of the bearing, increase the size of the stator of the motor without increasing the size of the motor stator. It is possible to provide an electric motor that can achieve this.

[Brief description of drawings]

FIG. 1 is a half sectional view of an electric motor according to an embodiment of the present invention.

FIG. 2 is a front view of a main part of a rotor shaft according to an embodiment of the present invention.

FIG. 3 is a half sectional view of a conventional electric motor.

[Explanation of symbols]

 1 Rotor 2 Rotor shaft 3 Stator 4 Stator winding 5 Bracket 6 Load side bearing 7 Anti-load side bearing 8 Shaft end 9 Screw hole 10 Vent hole

Claims (2)

[Scope of utility model registration request] 1. An electric motor comprising a bracket for supporting a rotor having a rotor shaft and a stator having a stator winding, and having a rotor shaft pivotally supported by a bearing mounted on the bracket. In the child, an electric motor in which a hole is formed in the rotor shaft on the anti-load side deeper than the width of the bearing from the shaft end of the rotor shaft. 2. The electric motor according to claim 1, wherein the hole provided at the shaft end of the rotor shaft on the non-load side is a screw hole in the same direction as the rotation direction of the electric motor.