JP2002369449A - Electric motor - Google Patents

Abstract

(57) [Object] The object of the present invention is to effectively reduce the size, weight, and cost by ensuring the reliability by cooling the heat generated from the stator with high efficiency. A flexible resin material (6) having a high thermal conductivity is sandwiched between the winding end (7) and the bracket (5) so that the winding and the bracket (5) are provided. It is effective to reduce the thermal resistance of the air and improve the heat radiation performance as compared with the case where the air is interposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine such as an electric motor, and more particularly to an electric motor which can be cooled by heat conduction inside the electric motor to improve heat radiation performance.

[0002]

2. Description of the Related Art In an electric motor for cooling by heat conduction inside an electric motor, a winding end of a stator and a bracket are adjacent to each other with an air layer, and the heat of the winding is transferred to the bracket through air. Had been moved to. In a water-cooled AC generator for a vehicle, a resin material is molded between a water-cooled pipe and a coil to improve heat radiation performance (Japanese Patent Laid-Open No. 11-14).
No. 6606).

[0003]

In a heat conduction cooling type motor, heat is transmitted from a winding end to a bracket and is radiated from a radiator plate in contact with the bracket. Calculations have shown that the value of the thermal resistance caused by the air layer between the winding end and the bracket greatly changes the winding temperature. If the thickness of the air layer is large, the winding temperature becomes high and approaches the temperature tolerance of the insulating material of the winding. Since the winding is deformed, it is difficult to increase the contact surface pressure between the winding end and the bracket in order to reduce the thermal resistance. If the size of the motor is reduced, the amount of heat generated will increase, and unless the heat radiation performance is increased, the temperature will rise to the allowable value of the coil temperature. Was.
SUMMARY OF THE INVENTION An object of the present invention is to provide an effective means for ensuring reliability, reducing the size and weight, and reducing the cost by mainly cooling the heat generated from the stator with high efficiency.

[0004]

Therefore, a flexible resin material having a high thermal conductivity is interposed between the winding end portion and the bracket to reduce the thermal resistance between the winding and the bracket, thereby forming an air layer having a certain thickness. It is possible to improve the heat radiation performance as compared with the case of interposing. The high heat conductive resin material is an independent sheet material different from the molding material between the winding and the bracket in the cited reference (Japanese Patent Laid-Open No. 11-146606).

[0005]

An embodiment of the present invention will now be described with reference to FIG. The shaft 2 fixed to the rotor 1 using a permanent magnet rotates in contact with the bearing 9. Rotor 1
The housing 4 is provided around the stator 8 outside the housing, and a winding is fixed inside the stator 8. A winding end 7 extends from a winding of the stator 8 via a resin material 6 having flexibility and high thermal conductivity in contact with a bracket 5 supporting the housing 4 from both sides. As shown in the vertical sectional view of the entire rotary electric machine to which the present invention is applied in FIG. 2, an encoder 3 for controlling the number of rotations and the like is provided on a bracket opposite to the heat sink 10. Although the heat generated from the windings of the stator part is partially transmitted to the iron core part, it is mainly transmitted to the winding end part 7 and is radiated by the radiator plate 10 attached to the bracket 5. The amount of heat generated from the iron core of the stator is mainly transmitted to the housing 4,
From the bracket 5. The direction of heat transfer from the iron core to the winding depends on the amount of heat generated by the iron core and the winding. In addition, since the thermal resistance increases at the contact surface inside the electric motor, the heat flow changes according to the value of the thermal resistance. The contact surface includes the contact surface between the winding and the iron core, the iron core and the housing 4, the housing 4 and the bracket 5, and the bracket 5 and the radiator plate 10. Although the winding end portion 7 and the bracket 5 are important heat dissipation paths, they cannot be brought into contact with each other by applying a high surface pressure. According to the calculation, since the thermal resistance of the resin material 6 part greatly affects the winding temperature, it is possible to make the air layer extremely thin and enhance the heat radiation performance by using a resin material sheet having a high thermal conductivity. is there.
The radiator plate 10 is cooled by conducting heat to a low-temperature object in contact with the radiator plate 10 or by cooling the radiator plate 10 by air. Further, the resin material 6 is not required at the winding end portion on the encoder side.

FIG. 3 shows another embodiment. In an example of the winding end portion 7, the winding end portion 7 is not molded, and the winding is mechanically formed,
It is in contact with the bracket 5 via a resin material 6 having high thermal conductivity. If the winding end portion 7 is fixed to the bracket 5 only through a resin having high thermal conductivity without using a mold, the thermal resistance of the mold is reduced and the thermal resistance of this portion is also reduced. In this case, since the winding is not molded, the diameter is several mm.
It is necessary to use a resin material that absorbs the unevenness of the winding.

FIG. 4 is a view showing another structure of the bracket 5 of FIG. 1, and a step 20 is provided inside the bracket 5 on the winding side.
Is provided to facilitate the fixing of the resin material 6 having high thermal conductivity. Although the number of processing steps for the bracket 5 increases, there is an advantage that the resin material 6 can be easily installed. The winding portion may or may not be molded.

FIG. 5 shows another embodiment.
In addition, a resin material 6 having high heat conductivity is fixed in advance with an adhesive material 11 to further improve the heat conductivity with the bracket 5. Glue the adhesive 11 to the bracket 5,
It may be fixed so as to be in contact with the winding end portion 7.

[0009]

According to the conventional method, an air layer exists in the winding and the end bracket portion. However, by introducing a resin material having a high thermal conductivity, the thermal resistance is reduced and the winding temperature of the motor is increased. Can be prevented. As a result, there is an effect that the motor can be reduced in size and weight while ensuring the reliability of the stator.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one embodiment of the present invention.

FIG. 2 is an overall cross-sectional view of the embodiment of the present invention shown in FIG.

FIG. 3 is a cross-sectional view of another embodiment different from the present invention shown in FIG.

FIG. 4 is a cross-sectional view of another embodiment different from the present invention shown in FIG.

FIG. 5 is a cross-sectional view of another embodiment different from the present invention shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotor, 2 ... Shaft, 3 ... Encoder, 4 ... Bearing, 5 ... Bracket, 6 ... High thermal conductive resin material, 7 ... Winding end part, 8 ... Stator, 9 ... Bearing, 10 ... Heat sink, 11 ... adhesive, 20 ... step of the bracket.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H603 AA11 AA15 BB01 BB02 CA01 CA05 CB03 CC01 CD21 EE11 FA16 5H609 BB03 BB19 PP02 PP06 PP08 PP09 QQ02 QQ23 RR58 RR71 RR74

Claims (2)

[Claims] 1. A stator comprising a stator winding and a stator core, a rotor using a permanent magnet, a housing covering the stator, and a bracket in contact with a heat sink, and controlling the amount of rotation. Motor having an encoder that performs
An electric motor characterized in that a flexible resin material is inserted between an end of a stator winding end axial direction and a bracket. 2. A stator comprising a stator winding and a stator core, a rotor using a permanent magnet, a housing covering the stator, and a bracket in contact with a heat sink, and controlling the amount of rotation. Motor having an encoder that performs
An electric motor characterized in that a flexible resin material is inserted between an axial end of a winding end of a stator and a bracket with a step.