KR20200022805A - Electric motor having improved heat-radiation ability and method of manufacturing the same - Google Patents

Abstract

Disclosed is an electric motor having improved heat-radiation performance. The disclosed electric motor comprises: a stator assembly including a coil winding; and a rotor disposed in the stator assembly. The stator assembly includes a stator body having a winding accommodation groove accommodating the coil winding, and a heat-radiation end part cover covering an end part of the coil winding protruding from the stator body. The heat-radiation end part cover includes 5 to 20% by weight of organosilicon resin, 60 to 80% by weight of aluminum oxide, and 10 to 30% by weight of aluminum hydroxide.

Description

ELECTRIC MOTOR HAVING IMPROVED HEAT-RADIATION ABILITY AND METHOD OF MANUFACTURING THE SAME

The present invention relates to an electric motor. More particularly, the present invention relates to an electric motor having improved heat dissipation performance and a method of manufacturing the same.

Recently, high-performance electric motors have been developed for use in electric vehicles.

The high-performance electric motor includes a coil wound on a stator. When the temperature of the coil is increased during operation of the electric motor, damage to the motor may occur or performance of the motor may be degraded.

Therefore, it is necessary to improve the heat dissipation performance of the electric motor, and in particular, it is necessary to form a heat dissipation path of heat generated from the coil and to improve heat transfer efficiency.

One object of the present invention is to provide an electric motor having heat dissipation performance to be improved.

Another object of the present invention is to provide a method of manufacturing the electric motor.

However, the problem to be solved by the present invention is not limited to the above-mentioned problem, and may be variously expanded within a range without departing from the spirit and scope of the present invention.

An electric motor according to exemplary embodiments of the present invention for achieving the above object of the present invention includes a stator assembly including a coil winding and a rotor disposed in the stator assembly. The stator assembly includes a stator body having a winding receiving groove for receiving the coil winding and a heat dissipation end cover covering an end of the coil winding protruding from the stator body. The heat dissipation end cover includes 5 wt% to 20 wt% of organosilicon resin, 60 wt% to 80 wt% of aluminum oxide, and 10 wt% to 30 wt% of aluminum hydroxide.

According to one embodiment, the organo silicone resin includes a polydimethylsiloxane resin having a vinyl group bonded to both ends.

According to an embodiment, the heat dissipation end cover may include 7 wt% to 15 wt% of organosilicon resin, 65 wt% to 75 wt% of aluminum oxide, 10 wt% to 20 wt% of aluminum hydroxide, and 0.01 wt% to 3 catalyst. Weight percent and 1 weight percent to 5 weight percent flame retardant.

According to one embodiment, the heat dissipation end cover contacts the end of the coil winding and the stator body.

According to one embodiment, the electric motor further comprises a housing surrounding the stator assembly, wherein the heat dissipation end cover contacts the end of the coil winding, the stator body and the housing.

According to one embodiment, the coil winding is impregnated in the heat dissipation varnish in the winding receiving groove, the heat dissipation varnish comprises a cured product of unsaturated polyester resin in which the heat dissipation filler is dispersed.

A method of manufacturing an electric motor according to an embodiment of the present invention includes preparing a stator assembly, disposing a rotor in the stator assembly, and coupling the stator assembly and a housing. The preparing of the stator assembly may include: impregnating a coil winding coupled with the stator body in a heat dissipating varnish composition and providing a heat dissipating elastic composition at an end of the coil winding protruding from the stator body, thereby providing an end of the coil winding. And forming a heat dissipation end cover to cover the heat dissipation elastic composition. The heat dissipation elastic composition may include 5 wt% to 20 wt% of organosilicon resin, 60 wt% to 80 wt% of aluminum oxide, and 10 wt% to 30 wt% of aluminum hydroxide. It includes.

According to exemplary embodiments of the present invention as described above, the heat dissipation performance of the electric motor is greatly improved by impregnating the coil windings of the stator of the electric motor in the heat dissipation varnish and providing a heat dissipation elastic cover at the ends of the exposed coil windings. It is possible to improve, thereby improving the reliability of the electric motor, it is possible to prevent the risk of performance degradation and damage due to high heat.

1 is a cross-sectional view of an electric motor according to an embodiment of the present invention.
2 is a perspective view illustrating a stator of an electric motor according to an embodiment of the present invention.
3 is a cross-sectional view showing a coil winding according to an embodiment of the present invention.
4, 5 and 6 are cross-sectional views of an electric motor according to embodiments of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention. As the inventive concept allows for various changes and numerous modifications, particular embodiments will be illustrated and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosure form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In the accompanying drawings, the dimensions of the structures are shown in an enlarged scale than actual for clarity of the invention.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, or combination thereof described in the specification, but one or more other features or numbers. It should be understood that it does not exclude in advance the possibility of the presence or the addition of steps, actions, components or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

1 is a cross-sectional view of an electric motor according to an embodiment of the present invention. 2 is a perspective view illustrating a stator of an electric motor according to an embodiment of the present invention. 3 is a cross-sectional view showing a coil winding according to an embodiment of the present invention.

Referring to FIG. 1, an electric motor according to an embodiment of the present invention includes a stator assembly 10 including a coil winding 14, a rotor 20 disposed in the stator assembly 10, and the rotor 20. ) Includes a drive shaft 30 coupled to the housing and a housing 40 surrounding the stator assembly 10.

The stator assembly 10 includes a stator body 12, a coil winding 14 wound around the stator body 12, and a heat dissipation end cover 16 coupled to an end of the coil winding 14.

As shown in FIGS. 1 and 2, the stator body 12 may have a cylindrical shape extending along the first direction D1. According to one embodiment, the stator body 12 may be formed on the inner surface, and have a winding receiving groove extending along the first direction D1. The winding receiving groove is disposed in plural along the circumferential direction of the stator body 12. The stator body 12 may include a metal.

The coil winding 14 may be wound around a protrusion forming a winding receiving groove of the stator body 12. For example, the coil winding 14 may be wound to extend along the first direction D1 in the winding receiving groove. For example, the coil winding 14 may be made of a highly conductive metal such as copper, and the outer surface of the coil may be insulated.

According to one embodiment, in the winding receiving groove, the coil winding 14 may be surrounded by a protective film 13. The protective film 23 may protect the coil winding 14 and prevent current leakage or short circuit. For example, the protective film 23 may include an insulation paper, an insulation film, a heat dissipation plastic film, or the like.

According to one embodiment, the coil winding 14 may be impregnated in the heat dissipation varnish 15. 3 is a cross-sectional view of the coil winding 14 along a second direction D2 perpendicular to the first direction D1.

As shown in FIG. 3, the heat dissipation varnish 15 may fill at least a portion of the gap inside the coil winding 14. The heat dissipation varnish 15 may transfer heat generated from the coil winding 14 to the stator body 12 to improve heat dissipation performance of the electric motor.

According to an embodiment, the heat dissipation varnish 15 may include a cured product of an unsaturated polyester resin in which a heat dissipation filler is dispersed.

When the coil winding 14 is wound around the stator body 12, a part of the coil winding 14 is not disposed in the winding receiving groove and protrudes along the first direction D1. An end portion of the exposed coil winding 14 does not contact the stator body 12, so that heat dissipation is not easy, and thus the temperature may increase significantly. According to an embodiment of the present invention, the heat dissipation end cover 17 may be coupled to the end of the coil winding 14 protruding from the stator body 12 to improve heat dissipation performance.

The heat dissipation end cover 16 includes a binder resin and a heat dissipation filler. For example, the binder resin may include an organosilicone resin.

For example, the organosilicon resin may include methyl vinyl silicone gum, dimethyl silicone gum, methylphenyl silicone gum, fluorosilicone gum, hydroxyldimethylsilium gum, methylvinylsilicon gum, or a combination thereof.

For example, the heat dissipation filler may be magnesium oxide, magnesium hydroxide, titanium dioxide, aluminum nitride, silicon nitride, boron nitride, aluminum oxide, aluminum hydroxide, silica, zinc oxide, barium titanate, strontium titanate, beryllium oxide, silicon carbide, or oxide oxide. Manganese or combinations thereof.

The heat dissipation filler may be in the form of powder. The granular shape may be a known shape, and for example, may have a plate shape, a spherical shape, a needle shape, a resin shape, or an amorphous shape. The heat dissipation filler may be appropriately selected in consideration of the desired physical properties of the heat dissipation elastic body, for example, vertical thermal conductivity, horizontal thermal conductivity, and the like. For example, the shape may be plate-shaped to improve horizontal thermal conductivity, and may be spherical to improve vertical thermal conductivity.

For example, the size of the heat dissipation filler may be an average particle diameter of 1 to 100㎛, preferably 1 to 50㎛.

According to an embodiment, the heat dissipation end cover 16 may include 5 wt% to 20 wt% of organosilicon resin, 60 wt% to 80 wt% of aluminum oxide, and 10 wt% to 30 wt% of aluminum hydroxide. have.

Preferably, the heat dissipation end cover 16 may include 7 wt% to 15 wt% of organosilicon resin, 65 wt% to 75 wt% of aluminum oxide, and 10 wt% to 20 wt% of aluminum hydroxide.

The heat dissipation end cover 16 is excellent in thermal conductivity due to the high heat dissipation filler content, and has an appropriate elasticity and ductility, so that the contact area with other members is large. Therefore, the heat dissipation performance is excellent. In addition, having flame retardancy, it is possible to prevent fire, damage and the like due to the high heat issued by the stator.

According to an embodiment, the heat dissipation end cover 16 may cover the end of the coil winding 14 and may contact the stator body 12. The heat dissipation end cover 16 may transfer heat generated from an end of the coil winding 14 to the stator body 12 to improve heat dissipation performance.

Preferably, the heat dissipation end cover 16 may be in contact with the housing 17. When the heat dissipation end cover 16 contacts the housing 17, heat dissipation performance may be improved by increasing a heat dissipation path.

The rotor 20 is disposed inside the stator assembly 10 and is coupled to the drive shaft 30. According to an embodiment, the rotor 20 may be spaced apart from the inner surface of the stator assembly 10 at regular intervals.

For example, the rotor 20 may have a cylindrical shape extending along the extending direction D1 of the drive shaft 30. The rotor 20 may include a plurality of rotor plates stacked along the extending direction D1 of the driving shaft 30, and may include a plurality of magnets disposed adjacent to an outer surface thereof.

The housing 40 may have a shape surrounding the stator assembly 10.

According to an embodiment, the inner surface of the housing 40 may contact the stator assembly 10. For example, an inner surface of the housing 40 may contact the stator body 12 and the heat dissipation end cover 16.

According to an embodiment, the housing 40 may be thermally connected to a heat sink, a heat pipe, a cooling member, or the like to transfer heat generated by the stator assembly 10.

A method of manufacturing an electric motor according to an embodiment of the present invention includes preparing a stator assembly, disposing a rotor in the stator assembly, and coupling the stator assembly and a housing.

The stator assembly is identical to the stator assembly of the electric motor according to an embodiment of the present invention described above. For example, as shown in FIGS. 1 and 3, the stator assembly is wound around the stator body 12, the stator body 12, and the coil winding 14 impregnated in the heat dissipation varnish 15. And a heat dissipation end cover 16 coupled to the end of the coil winding 14.

First, the coil winding 14 is wound around the stator body 12. The coil winding 14 is impregnated in the heat dissipating varnish composition, and then dried / cured to impregnate the coil winding 14 in the heat dissipating varnish 15. Next, a heat dissipation elastic composition is provided at the end of the coil winding 14, which protrudes from the stator body 12, to form a heat dissipation end cover 16 covering the end of the coil winding 14.

In order to increase the heat dissipation performance of the stator assembly 10, the heat dissipation varnish 15 needs to be uniformly filled in a large amount in the voids in the coil winding 14. For this purpose, it is preferable to use vacuum impregnation.

According to one embodiment, the heat dissipation varnish composition, 30 wt% to 40 wt% of unsaturated polyester resin, 30 wt% to 40 wt% of heat dissipation filler, 25 wt% to 35 wt% of reactive monomer, 1 wt% to 10 talc It may include a weight percent, 0.1% to 4% by weight alcoholic solvent and 0.1% to 4% by weight petroleum solvent.

For example, the unsaturated polyester resin can be obtained by the reaction of an acid anhydride and a hydroxyl compound. According to one embodiment, the unsaturated polyester resin may be obtained by the reaction of trimethylolpropane diallyl ether, propylene glycol, phthalic anhydride and maleic anhydride. When the content of the unsaturated polyester resin exceeds 40% by weight, the viscosity of the composition may increase, so that impregnation may proceed unevenly.

For example, the heat dissipation filler may be magnesium oxide, magnesium hydroxide, titanium dioxide, aluminum nitride, silicon nitride, boron nitride, aluminum oxide, aluminum hydroxide, silica, zinc oxide, barium titanate, strontium titanate, beryllium oxide, silicon carbide, or oxide oxide. Manganese or combinations thereof. When the content of the heat dissipation filler is less than 30% by weight, it is difficult to obtain a desired heat dissipation performance

For example, the reactive monomer may have an unsaturated bond and an aromatic ring capable of reacting with the unsaturated polyester resin. According to one embodiment, the reactive monomer may be styrene. The reactive monomer may lower the viscosity of the heat dissipation varnish composition so that impregnation may proceed uniformly, and may react with the unsaturated polyester resin to increase heat resistance of the heat dissipation varnish. In order to maintain an appropriate viscosity of the heat dissipating varnish composition, the content of the reactive monomer is preferably 25% by weight to 35% by weight.

The talc may improve thixotropy of the heat dissipating varnish composition. When the content of the talc exceeds 10% by weight, the viscosity of the composition may increase, so that impregnation may proceed unevenly.

The alcohol solvent and the petroleum solvent may improve the uniformity of the impregnation process by adjusting the viscosity of the heat dissipating varnish composition and controlling the volatilization rate of the solvent. According to an embodiment, the alcohol solvent may include ethanol, and the petroleum solvent may include aromatic hard naphtha.

According to an embodiment, the heat dissipating elastic composition may include 5 wt% to 20 wt% of organosilicon resin, 60 wt% to 80 wt% of aluminum oxide, and 10 wt% to 30 wt% of aluminum hydroxide.

Preferably, the heat dissipating elastic composition, 7% to 15% by weight of organosilicon resin, 65% to 75% by weight of aluminum oxide, 10% to 20% by weight of aluminum hydroxide, 0.01% to 3% by weight of catalyst and It may comprise 1 to 5% by weight of the flame retardant.

For example, the organosilicon resin may be a polydimethylsiloxane resin having a vinyl group bonded to both terminals. According to one embodiment, the organosilicon resin may be represented by the following formula (1). In formula (1), R1, R2, R3, R4, R5 and R6 each independently represent an alkyl group having 1 to 4 carbon atoms, a phenyl group, an aryl group or a cyanomethyl group, and n is a natural number. According to one embodiment, the weight average molecular weight of the organosilicon resin may be 300,000 to 600,000.

<Formula 1>

The organosilicon resin, by having rubber properties, provides elasticity to the heat dissipation end cover, and serves as a binder to disperse and fix the heat dissipation fillers.

Aluminum oxide has excellent electrical insulation properties and chemical stability. According to one embodiment, in order to increase the thermal conductivity of the heat dissipation end cover, it is preferable to increase the filling rate, and for this purpose, aluminum oxide particles having a wide particle size distribution may be used. For example, the diameter of the aluminum oxide particles may be 1 to 120㎛. According to an embodiment, the first particles having a diameter of 40 to 60 μm and the second particles having a diameter of 1 to 10 μm may be mixed and used in a weight ratio of 2: 1 to 3: 1. According to this, high filling rate and uniform dispersibility can be obtained. When the content of the aluminum oxide is too low, the thermal conductivity may be reduced, if excessive, the stability of the heat dissipation end cover may be lowered and the hardness may be increased.

Aluminum hydroxide is excellent in flame retardancy and can impart weight reduction characteristics. When the aluminum hydroxide is too small, flame retardancy may decrease.

The catalyst is for promoting the curing of the organosilicon resin, a metal catalyst, for example, a platinum-based catalyst and the like can be used.

For example, the flame retardant may include a phosphorus-based flame retardant such as tris (polyoxyalkylene) phosphate, tris (chlorinated polyol) phosphate, or trichlorobutylene oxide polyol.

In the above description, the present invention has been described through the embodiments shown in FIGS. 1 to 3, but the present invention is not limited thereto and may be implemented in various forms of embodiments without departing from the technical spirit of the present invention.

4, 5 and 6 are cross-sectional views of an electric motor according to embodiments of the present invention.

Referring to FIG. 4, an electric motor according to an embodiment of the present invention includes a stator assembly 10 including a coil winding 14, a rotor 20 disposed in the stator assembly 10, and the rotor 20. ) Includes a drive shaft 30 coupled to the housing and a housing 40 surrounding the stator assembly 10.

The stator assembly 10 is wound around the stator body 12, the stator body 12, the coil winding 14 impregnated in the heat dissipation varnish, the heat dissipation end cover coupled to the end of the coil winding 14 ( 17).

The heat dissipation end cover 17 is in contact with the stator body 12. Unlike the embodiment shown in FIG. 1, the heat dissipation end cover 17 may be spaced apart without contacting the housing 40. According to one embodiment of the present invention, even if the heat dissipation end cover 17 is not in contact with the housing 40, the heat dissipation can be controlled through the stator body 12 to control heat generation of the coil winding 14. .

Referring to FIG. 5, an electric motor according to an embodiment of the present invention includes a stator assembly 10 including a coil winding 14, a rotor 20 disposed in the stator assembly 10, and the rotor 20. ) Includes a drive shaft 30 coupled to the housing and a housing 40 surrounding the stator assembly 10.

The stator assembly 10 includes a stator body 12, a coil winding 14 wound around the stator body 12, and a heat dissipation cover 16 coupled to an end of the coil winding 14.

The housing 40 may have a cooling channel 42 for providing a cooling fluid. The cooling channel 42 may be formed in a groove shape on the inner surface of the housing 40 to be in contact with the stator body 12 of the stator assembly 10. Cooling fluid provided through the cooling channel 42 may increase the cooling effect by contacting the stator body 12.

In another embodiment, the housing 40 may have a cooling channel 43 for providing a cooling fluid, and as shown in FIG. 6, the cooling channel 42 is formed inside the housing 40. It may be formed and spaced apart from the stator body 12. Therefore, heat generated from the stator body 12 may be radiated to the cooling channel 42 through the housing 40.

According to the present invention, by impregnating the coil winding of the stator of the electric motor in the heat dissipation varnish and providing a heat dissipation elastic cover at the end of the exposed coil winding, it is possible to greatly improve the heat dissipation performance of the electric motor, thereby It is possible to improve the reliability and to prevent risks such as performance degradation and damage due to high heat.

While the above has been described with reference to embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. Will understand.

The electric motor according to the above-described exemplary embodiments may be used in various mechanical devices such as refrigerators, washing machines, construction equipment, tools, electric vehicles, and the like.

10: stator assembly 14: coil winding
15: heat dissipation varnish 16, 17: heat dissipation end cover
20: rotor 30: drive shaft
40: housing 42, 43: cooling channel

Claims (14)

A stator assembly comprising a coil winding; And
A rotor disposed within the stator assembly,
The stator assembly includes a stator body having a winding receiving groove for receiving the coil winding and a heat dissipation end cover covering an end of the coil winding protruding from the stator body,
The heat dissipation end cover may include 5 wt% to 20 wt% of organosilicon resin, 60 wt% to 80 wt% of aluminum oxide, and 10 wt% to 30 wt% of aluminum hydroxide. The electric motor of claim 1, wherein the organo silicone resin is a polydimethylsiloxane resin having vinyl groups bonded to both ends thereof. The method of claim 1, wherein the heat dissipation end cover is 7 to 15% by weight of organosilicon resin, 65 to 75% by weight of aluminum oxide, 10 to 20% by weight of aluminum hydroxide, 0.01 to 3% of catalyst An electric motor, comprising 1% to 5% by weight and flame retardant. The electric motor of claim 1, wherein the heat dissipation end cover is in contact with an end of the coil winding and the stator body. The electric motor of claim 1, further comprising a housing surrounding the stator assembly, wherein the heat dissipation end cover contacts the end of the coil winding, the stator body, and the housing. 2. The electric motor of claim 1, wherein the coil winding is impregnated in a heat dissipation varnish in the winding receiving groove, and the heat dissipation varnish comprises a cured product of an unsaturated polyester resin in which a heat dissipation filler is dispersed. Preparing a stator assembly;
Placing a rotor in the stator assembly; And
Coupling the stator assembly and a housing;
Preparing the stator assembly,
Impregnating the coil windings associated with the stator body into the heat dissipating varnish composition; And
Providing a heat dissipation elastic composition at an end of the coil winding protruding from the stator body to form a heat dissipation end cover covering the end of the coil winding,
The heat dissipation elastic composition, 5% to 20% by weight of the organosilicon resin, 60% to 80% by weight of aluminum oxide and 10% to 30% by weight of aluminum hydroxide, the manufacturing method of the electric motor. The method of claim 7, wherein the heat dissipating elastic composition, organosilicon resin 7% to 15% by weight, aluminum oxide 65% to 75% by weight, aluminum hydroxide 10% to 20% by weight, catalyst 0.01% to 3% It comprises a weight percent and 1% to 5% by weight of a flame retardant, wherein the organo silicone resin is a polydimethylsiloxane resin having a vinyl group bonded to both ends. The heat dissipating varnish composition according to claim 7, wherein the heat dissipating varnish composition comprises 30% to 40% by weight of unsaturated polyester resin, 30% to 40% by weight of heat dissipating filler, 25% to 35% by weight of reactive monomer, 1% to 10% of talc. Weight%, 0.1% to 4% by weight of alcohol solvent and 0.1% to 4% by weight of petroleum solvent. The heat dissipation filler of the heat dissipation varnish composition according to claim 9, wherein the heat dissipation filler of the heat dissipation varnish composition includes magnesium oxide, magnesium hydroxide, titanium dioxide, aluminum nitride, silicon nitride, boron nitride, aluminum oxide, aluminum hydroxide, silica, zinc oxide, barium titanate, strontium titanate, and oxides. A method of manufacturing an electric motor, characterized in that it comprises at least one selected from the group consisting of beryllium, silicon carbide and manganese oxide. 10. The method of claim 9, wherein the reactive monomer comprises styrene. The method of claim 9, wherein the alcohol solvent comprises ethanol. 10. The method of claim 9, wherein the petroleum solvent comprises aromatic hard naphtha. 10. The method of claim 9, wherein the impregnation of the heat dissipating varnish composition is carried out by vacuum impregnation.

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