KR102764997B1 - Electric motor - Google Patents

Abstract

The present invention relates to an electric motor, and more specifically, to an electric motor capable of efficiently cooling a stator winding, which generates the most heat among components of an electric motor, and having a compact structure. To this end, an electric motor according to the present invention includes a rotor having a motor shaft, a fixed core disposed opposite the rotor, a stator having a winding wound around the fixed core, a main body wrapping around the fixed core, and a housing provided with covers coupled to both axial sides of the main body, wherein a heat dissipation portion is formed on the cover that wraps the winding exposed along the axial direction of the main body, and a transfer member is provided on the heat dissipation portion for thermally contacting the winding and the heat dissipation portion so that heat generated from the winding is transferred to the heat dissipation portion.

Description

Electric motor {ELECTRIC MOTOR}

The present invention relates to an electric motor, and more specifically, to an electric motor having a compact structure and capable of efficiently cooling a stator winding, which generates the most heat among components of the electric motor.

Electric motors used in electric vehicles generally have high output characteristics, and to secure this high output, high current is applied to the stator windings. Due to this high current applied, the most heat is generated in the motor windings.

However, since the heat generated in an electric motor in this way limits the continuous and instantaneous maximum output of the electric motor and reduces its lifespan, it is very important to dissipate this heat in the electric motor.

In the past, some technologies were disclosed to allow cooling fluid to flow around the outside of the stator or the windings in order to cool an electric motor, but there was a limitation in that the windings, which generate the most heat, could not be sufficiently cooled.

In addition, since the path through which the cooling fluid flows is formed along the circumference of the stator core, the size of the electric motor increases unnecessarily, which limits the mountability.

Therefore, there is a need to develop an electric motor that can efficiently cool the windings of the electric motor while also having a compact structure.

Korean Patent Publication No. 10-2007-0067436 (published on June 28, 2007)

The technical problem to be solved by the present invention is to provide an electric motor having a compact structure and capable of efficiently cooling a stator winding, which generates the most heat among the components of an electric motor.

According to the present invention for solving the above technical problem, an electric motor comprises a rotor having a motor shaft, a fixed core disposed opposite to the rotor, a stator having a winding wound around the fixed core, a main body wrapping around the circumference of the fixed core, and a housing provided with a cover coupled to both axial sides of the main body, wherein a heat dissipation portion is formed on the cover wrapping the winding exposed along the axial direction of the main body, and a transfer member is provided on the heat dissipation portion for thermally contacting the winding and the heat dissipation portion so that heat generated from the winding is transferred to the heat dissipation portion.

At this time, the transmission member may be provided on the inner surface of the heat dissipation part to surround the coil when assembling the cover.

Alternatively, the cover may be formed with an extension extending along the axial direction, and a heat dissipation path through which a cooling fluid flows may be formed in the extension.

At this time, the heat dissipation path can be formed so that the cooling fluid flows in a direction from the radially inner side to the radially outer side.

In addition, the heat dissipation path may be formed in a spiral shape, and an inlet may be provided on a radially inner side of the heat dissipation path, and an outlet may be provided on a radially outer side of the heat dissipation path.

In addition, a heat dissipation fin extending along the axial direction may be formed on the outer surface of the cover.

At this time, the heat dissipation fin may be arranged on an axial extension line of the heat dissipation path and may be formed to extend along the axial direction.

Alternatively, the heat dissipation fins may be formed to extend along the axial direction and arranged between adjacent heat dissipation paths.

The electric motor of the present invention having the above-described configuration forms a heat dissipation portion in a cover covering the stator winding, and is provided with a transmission member that thermally contacts the winding and the heat dissipation portion so that heat generated in the stator winding is effectively dissipated through the heat dissipation portion, thereby enabling efficient cooling of the stator winding.

In addition, since the heat dissipation section and the heat dissipation path through which the cooling fluid flows are formed to extend along the axial direction of the main body, a compact structure is achieved.

In addition, heat dissipation fins are formed together with the cooling fluid, enabling more efficient cooling of the stator winding.

Figure 1 is a perspective view of an electric motor according to the present invention.
Figure 2 is an exploded perspective view of an electric motor according to the present invention.
Figure 3 is a cross-sectional view of an electric motor according to the present invention.
Fig. 4 is a cross-sectional view illustrating in detail the heat dissipation path of the present invention.
FIG. 5 is a cross-sectional view illustrating a cover according to one embodiment of the present invention, and FIG. 6 is a cross-sectional view illustrating a cover according to another embodiment of the present invention.

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, in order to clearly describe the present invention, parts that are not related to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

In this specification, it should be understood that terms such as "include" or "have" are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof. In addition, when it is said that a part such as a layer, film, region or plate is "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between. Conversely, when it is said that a part such as a layer, film, region or plate is "under" another part, this includes not only the case where it is "directly under" the other part, but also the case where there is another part in between.

FIG. 1 is a perspective view of an electric motor according to the present invention, FIG. 2 is an exploded perspective view of an electric motor according to the present invention, FIG. 3 is a cross-sectional view of an electric motor according to the present invention, FIG. 4 is a cross-sectional view illustrating a heat dissipation path of the present invention in detail, FIG. 5 is a cross-sectional view illustrating a cover according to one embodiment of the present invention, and FIG. 6 is a cross-sectional view illustrating a cover according to another embodiment of the present invention.

As illustrated in FIGS. 1 to 3, an electric motor according to the present invention includes a rotor (200) having a motor shaft (10), a fixed core (110) facing the rotor (200), a stator (100) having a winding (120) wound around the fixed core (110), and a housing (300) having a main body (310) surrounding the circumference of the fixed core (110) and covers (320) coupled to both axial sides of the main body (310), and a heat dissipation part (321) formed in the cover (320) to surround the winding (120) exposed along the axial direction of the main body (310).

As described above, in the case of an electric motor, the most heat is generated in the winding (120) wound on the fixed core (110), and to release the heat generated in the winding (120), a heat dissipation part (321) that surrounds the winding (120) is formed in the cover (320) coupled to both sides of the main body (310).

This cover (320) includes a front cover (320a) coupled to one side of the main body (310) and a rear cover (320b) coupled to the other side of the main body (310), and the heat dissipation part (321) described above can be formed on at least one cover (320) among the front cover (320a) and the rear cover (320b).

At this time, the heat dissipation unit (321) is provided with a transfer member (321a) that thermally contacts the coil (120) and the heat dissipation unit (321) so that the heat generated from the coil (120) is transferred to the heat dissipation unit (321).

In general, the axial height of the winding (120) wound on the fixed core (110) is not arranged in a constant manner. This is because, during the winding process of the electric motor, the bundle of windings (120) is wound in such a way that they penetrate the slot formed in the fixed core (110) multiple times.

Therefore, in order to efficiently dissipate heat from the winding (120) formed with an axial height that is not constant, it is important that the winding (120) and the heat dissipation member (321) are arranged so that they are in thermal contact, and as described above, the electric motor according to the present invention is configured such that the heat generated from the winding (120) is transferred to the heat dissipation member (321) by providing a transfer member (321a) that thermally contacts the winding (120) and the heat dissipation member (321).

This transmission member (321a) is provided on the inner surface of the heat dissipation member (321) to surround the coil (120) when assembling the cover (320).

That is, when the cover (320) is assembled while the inner surface of the heat dissipation part (321) is partially filled with the transmission member (321a), the transmission member (321a) wraps around the winding (120), causing the winding (120) and the heat dissipation part (321) to come into thermal contact.

As this transfer member (321a), a molding material with excellent heat transfer performance, such as thermal grease, can be used, but it is not necessarily limited to this configuration, and any configuration can be used as long as it can be configured to make thermal contact between the winding (120) and the heat dissipation member (321) in a form that wraps around the winding (120).

In this way, when the transmission member (321a) is provided, stable thermal contact between the coil (120) and the heat dissipation member (321) is possible even if the axial height of the coil (120) is not formed uniformly, and heat transferred through the heat dissipation member (321) is released to the outside, enabling efficient cooling of the coil (120).

Alternatively, an extension (330) extending along the axial direction may be formed in the cover (320), and a heat dissipation path (331) through which a cooling fluid flows may be formed in the extension (330).

That is, the heat generated in the coil (120) is transferred to the heat dissipation part (321) of the cover (320) through the transfer member (321a). In order to effectively release the heat transferred to the heat dissipation part (321), an extension part (330) is formed along the axial direction of the cover (320), and a heat dissipation path (331) through which a cooling fluid flows is formed in this extension part (330).

At this time, it is preferable that the extension (330) be formed to extend along the axial direction. If the extension (330) is formed along the circumference of the fixed core (110), the size of the electric motor may increase excessively, which may reduce the mountability. However, since the extension (330) of the electric motor according to the present invention is formed to extend along the axial direction, it has a compact structure, thereby improving the mountability.

At this time, the aforementioned heat dissipation path (331) can be formed so that the cooling fluid flows in a direction from the radially inner side to the radially outer side.

The cooling fluid flowing along the heat dissipation path (331) increases in temperature as it exchanges heat with the heat dissipation unit (321). As the temperature of the cooling fluid increases, the heat dissipation performance decreases.

Therefore, the cooling fluid is configured to first perform heat exchange with the radially inner side of the winding (120) where the most heat is generated in the electric motor, and then perform heat exchange while moving to the radially outer side where heat generation is relatively less. This is because efficient cooling is possible even if the heat dissipation performance of the cooling fluid decreases as the temperature rises.

In addition, as shown in FIG. 4, the heat dissipation path (331) may be formed in a spiral shape, and an inlet (332) may be provided on the radially inner side of the heat dissipation path (331), and an outlet (333) may be provided on the radially outer side of the heat dissipation path (331).

In order for the cooling fluid to flow smoothly through the inside of the heat dissipation path (331), it is necessary to reduce the path resistance. As described above, when the heat dissipation path (331) is formed in a spiral shape, the heat dissipation path (331) is formed evenly in all parts of the heat dissipation part (321), while reducing the path resistance, thereby enabling the smooth flow of the cooling fluid.

In addition, as described above, the heat dissipation performance of the cooling fluid decreases as the temperature of the cooling fluid increases while exchanging heat with the heat dissipation unit (321), but by forming an inlet (332) so that a low-temperature cooling fluid flows into the radially inner side of the heat dissipation passage (331) formed in a spiral shape, and forming an outlet (333) so that a relatively high-temperature cooling fluid flows out into the radially outer side of the heat dissipation passage (331), efficient cooling becomes possible.

In addition, as shown in FIGS. 5 and 6, a heat dissipation fin (340) extending along the axial direction may be formed on the outer surface of the cover (320). At this time, as shown in FIG. 1, the heat dissipation fin (340) may be arranged in a spiral shape.

That is, the heat generated in the coil (120) is transferred to the heat dissipation unit (321), and the heat transferred to the heat dissipation unit (321) is released through the cooling fluid flowing along the heat dissipation path (331) formed in the extension unit (330) and at the same time released to the outside through the heat dissipation fin (340) formed on the outer surface of the cover (320), thereby improving the heat dissipation performance.

At this time, the heat dissipation fin (340) may be formed to extend along the axial direction by being positioned on the axial extension line of the heat dissipation path (331), as shown in FIG. 5.

As described above, the heat generated in the coil (120) is transferred to the cooling fluid flowing along the heat dissipation path (331) formed in the extension (330), and the temperature of this cooling fluid increases as heat is transferred.

However, if the temperature of the cooling fluid rises in this way, the heat dissipation performance of the cooling fluid may be reduced to some extent, but in the case of the present invention, by forming a heat dissipation fin (340) on the axial extension of the heat dissipation passage (331), when heat is transferred to the cooling fluid flowing along the heat dissipation passage (331) and the temperature rises, the heat is released to the outside to prevent the temperature of the cooling fluid from rising, thereby stably securing the heat dissipation performance of the cooling fluid.

Alternatively, the heat dissipation fin (340) may be formed to extend along the axial direction and be positioned between adjacent heat dissipation channels (331), as illustrated in FIG. 6.

As described above, the heat generated in the coil (120) is transferred to the cooling fluid flowing along the heat dissipation passage (331) formed in the extension (330), and as the heat is transferred, the temperature of the cooling fluid increases. If the temperature of the cooling fluid increases in this way, the heat dissipation performance of the cooling fluid may decrease to some extent. To this end, in the case of the present invention, heat dissipation fins (340) are formed between adjacent heat dissipation passages (331) so that even if the heat dissipation performance of the cooling fluid is reduced to some extent, heat can be released to the outside through the heat dissipation fins (340), thereby stably securing the heat dissipation performance of the cooling fluid.

Although one embodiment of the present invention has been described, the spirit of the present invention is not limited to the embodiment presented in this specification, and those skilled in the art who understand the spirit of the present invention will be able to easily suggest other embodiments by addition, change, deletion, addition, etc. of components within the scope of the same spirit, but this will also be considered to fall within the spirit of the present invention.

10: Motor shaft 100: Stator
110 : Fixed core 120 : Winding
200 : Rotor 300 : Housing
310 : Main body 320 : Cover
320a: Front cover 320b: Rear cover
321: Radiating member 321a: Transmission member
330 : Extension 331 : Heat dissipation Euro
332 : Inlet 333 : Outlet
340 : Radiator Fin

Claims (8)

Rotor having a motor shaft;
A stator having a fixed core positioned opposite to the rotor and a winding wound around the fixed core; and
A housing having a main body that surrounds the circumference of the fixed core and a cover that is coupled to both axial sides of the main body;
Including,
The above cover is formed with a heat dissipation portion that surrounds the winding exposed along the axial direction of the main body.
The above heat dissipation part is provided with a transfer member that thermally contacts the winding and the heat dissipation part so that heat generated from the winding is transferred to the heat dissipation part.
The above cover is formed with an extension extending along the axial direction,
In the above extension, a heat dissipation path through which a cooling fluid flows is formed,
The above heat dissipation path is formed in a spiral shape,
An electric motor in which heat dissipation fins are formed on the outer surface of the cover so as to extend along the axial direction and are arranged in a spiral shape. In the first paragraph,
The above-mentioned transmission member is an electric motor provided on the inner surface of the heat dissipation part so as to surround the winding when assembling the cover. delete In the first paragraph,
An electric motor in which the above heat dissipation path is formed so that cooling fluid flows in a direction from the radially inner side to the radially outer side. In paragraph 4,
An inlet is provided on the radially inner side of the above heat dissipation path,
An electric motor having an outlet provided on the radially outer side of the above heat dissipation path. delete In the first paragraph,
An electric motor in which the above heat dissipation fins are arranged on an axial extension line of the above heat dissipation path and are formed to extend along the axial direction. In the first paragraph,
An electric motor in which the above heat dissipation fins are arranged between adjacent heat dissipation channels and extend along the axial direction.

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