JPH08196058A - Electric rotating machine with rotation detector - Google Patents

Abstract

PURPOSE: To obtain a small-sized and light-weight electric rotating machine with rotation detector in which the cooling effect of rotation detector is enhanced by providing a heat transmission member having one end side fitted tightly to a fixed part and the other end side fitted tightly to the inside of a cover. CONSTITUTION: A hollow tubular heat transmission member 5 fitted tightly on the inside thereof to a fixed part 31 and on the outside thereof to the inside of a cover 4 is made of a material having high thermal conductivity, e.g. copper or aluminum. Heat generated from a stator 12 or a rotor 13 is transmitted through a thermal insulation board 2 to the fixed part and through a rotary shaft 16 and a bearing 30 to the fixed part 31 thence transmitted through the heat transmission member 5 to the cover 4 from which it is discharged to the outer air. With such structure, temperature rise of elements in a detection circuit and the like is suppressed and the cooling effect of a rotation detector is enhanced. Furthermore, a small-sized and light-weight electric rotating machine with rotation detector can be obtained because no coupling nor cooling fan is employed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric machine such as an electric motor provided with a rotation detector for detecting a rotation position and a rotation speed, and more particularly to one for enhancing a cooling effect of the rotation detector.

[0002]

2. Description of the Related Art Conventionally, when a rotational position or rotational speed of a rotating shaft of an electric motor is fed back to control the speed of the electric motor, a rotation detector is connected to the rotating shaft of the electric motor. Since semiconductor elements whose characteristics tend to change when the temperature rises are used, the device is designed to prevent the heat generated by the stator and rotor of the motor from being transferred to the rotation detector. The configuration is, for example, as shown in FIG.
The rotation part B of the rotation detector B is coupled to the rotation load axis end of the rotation axis A1 via a coupling A3 provided with a cooling fan A2.
1, or as shown in FIG. 6, the rotation part B1 of the rotation detector B is provided with a cooling fan B2, and the rotation part B1
Is directly fixed to the rotating shaft A1 of the electric motor A, and before the heat of the rotating shaft A1 of the electric motor A is transferred to the rotating portion B1 of the rotation detector B, the heat of the rotating shaft A1 is dissipated by the cooling fan A2 or B2. Are disclosed (for example, JP-A-63-234857 and JP-A-2-53257).

[0003]

However, in the prior art, since the coupling is provided between the rotating shaft of the electric motor and the rotating portion of the rotation detector and the cooling fan is provided, the length of the electric motor in the axial direction is increased. However, there is a problem that the length becomes longer and the size in the radial direction becomes larger, which hinders the reduction in size and weight of the electric motor with a rotation detector. SUMMARY OF THE INVENTION It is an object of the present invention to provide a small and lightweight rotating electric machine with a rotation detector, which enhances the cooling effect of the rotation detector.

[0004]

In order to solve the above problems, the present invention is directed to a stator fixed to a frame, a rotor opposed to the stator with a gap, and fixed to the anti-load side of the frame. A heat insulating plate, a rotary shaft to which the rotor is fixed, a fixed portion supported by a bearing on the rotary shaft and fixed to the heat insulating plate so as not to be displaced in the rotation direction, and a rotation detecting portion provided. In a rotary electric machine with a rotation detector, comprising: a rotary part fixed to the rotary shaft; a substrate fixed to the fixed part; a detection circuit element provided on the substrate; and a cover covering the rotary part and the fixed part. The heat transfer member has one side that is in close contact with the fixing portion and the other side is in close contact with the inside of the cover. Further, the heat insulating plate is formed in a cylindrical shape, the flat plate-shaped cover is fixed to an end portion of the heat insulating plate, and the heat transfer member is extended in the axial direction and brought into close contact with the cover. Further, the transmission member is one in which one side of a spring made of a material having a high thermal conductivity is fixed to the inside of the cover and the other side is in contact with the detection circuit element.

[0005]

With the above means, a heat transfer member is provided between the fixed portion of the rotation detector coupled to the rotation shaft of the electric motor and the cover, or between the detection circuit element and the cover, and the rotation detector passes through the rotation shaft of the electric motor. Since the heat transferred to the fixed part and the detection circuit element is transferred to the cover by the heat transfer member and radiated to the outside air, the temperature rise of the rotation detection part and the detection circuit element can be suppressed to a low level.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing a first embodiment of the present invention. In the figure, 1 is an electric motor, 11 is a hollow cylindrical frame of the electric motor 1, 12 is a stator fixed inside the frame 11, 13 is a rotor facing the inside of the stator 12 with a gap, and 14 is a frame. A bracket fixed to the load-side end face of 11, a bracket fixed to the counter-load side end face, and a rotating shaft 16 to which the rotor 13 is fixed are supported by bearings 17 and 18 provided on the brackets 14 and 15.
2 is a heat insulating plate fixed to the end face of the bracket 15 on the anti-load side, 3 is a rotation detector, 31 is a bearing supported by the rotating shaft 16 by a bearing 30, and is fixed to the insulating plate 2 so as not to be displaced in the rotational direction. It is a department. Reference numeral 32 is a rotary unit fixed to the rotary shaft 16, and 33 is a slit disk fixed to the rotary unit 32. The fixed portion 31 is provided with a rotation detecting portion 34 including a light emitting element and a light receiving element so as to sandwich the slit disk 33. Reference numeral 35 denotes a substrate fixed to the fixing portion 31, on which a detection circuit element 36 is provided. 4 is a cover for covering the rotation detector 3, 5
Is a hollow cylindrical heat transfer member whose inner side is in close contact with the fixing portion 31 and whose outer side is in close contact with the inner side of the cover 4, and is made of a material having a high thermal conductivity such as copper or aluminum. The heat generated by the stator 12 and the rotor 13 is transmitted to the fixed portion via the heat insulating plate 2, passes through the rotary shaft 16, and
Although it is transmitted to the fixed portion 31 via the bearing 30, the fixed portion 3
The heat transferred to 1 passes through the heat transfer member 5, is transferred to the cover 4, and is radiated to the outside air. Therefore, the heat transferred to the substrate 35 is extremely small, and the temperature rise of the rotation detection unit 34 and the detection circuit element 36 can be suppressed low.

FIG. 2 is a side sectional view showing a second embodiment of the present invention, in which the heat insulating plate 2 described in the first embodiment is formed in a cylindrical shape and a flat cover 4 is provided at the end thereof. In addition to being fixed, the heat transfer member 5 is extended in the axial direction and brought into close contact with the cover 4. Thereby, the stator 1 of the cover 4
The distance from 2 can be increased, the heat transferred from the stator 12 can be reduced, and the heat transferred from the rotor 13 can be transferred to the cover 4. FIG. 3 is a side sectional view showing a third embodiment of the present invention, in which a heat transfer member 6 fixed by a spring made of a material having a high heat conductivity is fixed inside the cover 4 of the above embodiment. is there. When the cover 4 is fixed to the heat insulating plate 2, the heat transfer member 6 comes into contact with the detection circuit element 36 provided on the substrate 35 by the spring force. Therefore, the heat transferred to the detection circuit element 36 is directly
The cover 4 radiates heat to the outside air through the heat transfer member 6. The heat transfer member 6 has a U-shaped spring 61 shown in FIG. 4A in which a flat plate made of spring steel is formed in a U-shape, and a rubber 62 in which metal powder shown in FIG. And a metal block 63 may be used, or a metal coil spring 64 shown in (c) may be used.

[0008]

As described above, according to the present invention, the heat transfer member is provided between the cover of the rotation detector fixed to the rotary shaft of the electric motor and the cover, and the rotation is detected through the rotary shaft of the electric motor. Since the heat transmitted to the fixed portion of the fixed portion is transmitted to the cover by the heat transfer member and radiated to the outside air, the temperature rise of the detection circuit element and the like provided in the fixed portion can be suppressed to a low level. Further, since no coupling or cooling fan is provided between the rotating shaft of the electric motor and the rotating portion of the rotation detector, the axial length of the electric motor may become long or the size in the radial direction may become large. Therefore, there is an effect that it is possible to provide a small and lightweight rotating electric machine with a rotation detector.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a first embodiment of the present invention.

FIG. 2 is a side sectional view showing a second embodiment of the present invention.

FIG. 3 is a side sectional view showing a third embodiment of the present invention.

FIG. 4 is a side view showing a heat transfer member according to a second embodiment of the present invention.

FIG. 5 is a side sectional view showing a conventional example.

FIG. 6 is a side sectional view showing a conventional example.

[Explanation of symbols]

1 electric motor, 11 frame, 12 stator, 13 rotor, 14, 15 bracket, 16 rotating shaft, 17, 1
8, 30 Bearing, 2 Heat insulation plate, 3 Rotation detector, 31
Fixed part, 32 rotating part, 33 slit disk, 34
Rotation detector, 35 substrate, 36 detection circuit element, 4 covers, 5 and 6 heat transfer member, 61 U-shaped spring, 62 rubber, 63 metal block, 64 coil spring

Claims (3)

[Claims] 1. A stator fixed to a frame, a rotor facing the stator through a gap, a heat insulating plate fixed to an anti-load side of the frame, and a rotary shaft fixed to the rotor. A fixed part supported by a bearing on the rotating shaft and fixed to the heat insulating plate so as not to be displaced in the rotation direction and provided with a rotation detecting part; a rotating part fixed to the rotating shaft; and a fixed part. In a rotary electric machine with a rotation detector comprising a fixed substrate, a detection circuit element provided on the substrate, and a cover that covers the rotating portion and the fixed portion, one side is in close contact with the fixed portion, and the other side is the cover. A rotary electric machine with a rotation detector, comprising a heat transfer member that is in intimate contact with the inside. 2. The heat insulating plate is formed in a cylindrical shape, the flat plate-shaped cover is fixed to an end of the heat insulating plate, and the heat transfer member is extended in the axial direction to be in close contact with the cover. A rotating electric machine with a rotation detector according to 1. 3. The transmission member has one side of a spring made of a material having a high thermal conductivity fixed to the inside of the cover, and the other side of the transmission member brought into contact with the detection circuit element provided in the fixing portion. A rotating electric machine with a rotation detector according to 1 or 2.