KR102018230B1 - Electric motor - Google Patents

Abstract

The present invention relates to an electric motor. The electric motor comprises: a motor housing; a stator provided inside the motor housing; and a rotor installed to be rotatable inside the stator. The motor housing includes: an outer housing having a first cooling path inside; and an inner housing arranged inside the outer housing and having a second cooling path to perform heat exchange with the first cooling path. By realizing an oil-cooled and water-cooled complex cooling method, cooling efficiency and cooling performance can be increased.

Description

Electric motor {ELECTRIC MOTOR}

The present invention relates to an electric motor having an oil cooling and a water cooling composite cooling flow path structure.

Recently, an electric vehicle (including a hybrid vehicle) including an electric motor as a driving source for driving a vehicle has been released as a future vehicle due to its excellent fuel efficiency.

In general, the motor has a rotor and a stator, and the rotor may be rotatably provided inside the stator.

The stator includes a stator coil wound around the stator core, and when a current flows through the stator coil to rotate the rotor, technologies are developed to generate heat in the stator coil and cool the heat generated in the motor.

In a drive system including an electric motor and an inverter for driving the motor, cooling of the heat generated by the motor and the inverter plays an important role in miniaturization and efficiency improvement of the drive system.

Conventional motor cooling systems employ an indirect cooling system in which cooling water is circulated inside the housing to indirectly cool the motor, and a direct cooling system in which oil is directly injected to a stator or rotor to cool the motor.

The direct cooling method has a higher cooling efficiency and a good cooling performance than the indirect cooling method. Recently, research and development on the direct cooling method has been actively conducted.

In addition, looking at the prior patent document related to the conventional direct cooling motor is as follows.

Patent Document 1 discloses a motor cooling structure for directly cooling a stator, a rotor, and a shaft by pumping oil immersed in the bottom surface of a motor housing by an oil churning device.

However, Patent Literature 1 is not equipped with an injection device for directly injecting oil into the stator coil, which generates the most heat, so that there is a limit in improving the cooling performance of the motor. There is.

In addition, US 2004/0163409 A1 (hereinafter referred to as Patent Document 2; Pub. Date: Aug. 26, 2004) has a motor cooling structure that uses oil cooling type or water cooling type separately for cooling the motor. Is disclosed.

In patent document 2, in the case of oil-cooling, an oil flow path is configured to surround the stator coil, and the oil directly cools the motor by absorbing heat generated from the stator coil.

In the oil-cooled case, a heat exchanger is provided outside the motor housing, and is configured to cool the oil by heat-exchanging oil with heat that has absorbed heat from the stator coil.

In addition, in the case of water cooling, a cooling water flow path is formed inside the motor housing, and the cooling water flowing in the cooling water flow path cools the motor housing to transfer heat generated in the stator coil to the stator core and the motor housing, thereby indirectly cooling the motor.

However, Patent Document 2 has the following problems.

First, in the case of oil-cooling, the cooling efficiency and cooling performance is good, but in order to lower the temperature of the oil, a heat exchanger must be separately provided on the outside of the housing, causing a cost increase and disadvantageous in miniaturizing the electric motor.

Secondly, in the case of water-cooling, there is an advantage of not having to provide a heat exchanger separately, but there is a disadvantage in that the cooling efficiency and cooling performance are poor.

The present invention has been made to solve the conventional problems, and has a complex cooling flow path structure that can be applied to oil-cooled and water-cooled at the same time, to improve the cooling efficiency and cooling performance, as well as to provide a heat exchanger outside the motor housing separately. It is an object of the present invention to provide an electric motor that can greatly contribute to cost reduction and miniaturization of the motor.

In addition, an object of the present invention is to provide an electric motor having an injection hole capable of directly injecting oil into a stator to increase cooling efficiency and improve cooling performance.

In order to achieve the above object, the electric motor having a water-cooled complex cooling structure according to the present invention, the motor housing; A stator provided inside the motor housing; A rotor rotatably installed inside the stator, the motor housing comprising: an outer housing having a first cooling passage through which oil flows; And an inner housing disposed in the outer housing and having a second cooling passage through which cooling water flows inside the outer housing so as to exchange heat with the first cooling passage.

The electric motor further includes a plurality of injection holes which are formed in the inner housing so as to communicate with the first cooling passage and inject the oil into the inner housing.

According to such a water-cooled composite cooling structure, oil flows along a first cooling flow path formed inside the outer housing and is directly injected to a stator coil located inside the inner housing through a plurality of injection holes, so that the most heat is generated. By directly cooling the generated stator coils and the like, the cooling efficiency and the cooling performance which are advantages of the direct cooling method can be improved.

In addition, the coolant flows along the second cooling flow path formed inside the inner housing, and is disposed inside the outer housing so as to exchange heat with the oil to cool the oil, so that a heat exchanger does not have to be separately provided outside the motor housing. It can greatly contribute to saving and miniaturization of the motor.

According to an example related to the present invention, the first cooling passage and the second cooling passage may extend in a direction crossing each other.

According to an example related to the present invention, the first cooling passage may extend in the longitudinal direction of the outer housing, and the second cooling passage may extend in the circumferential direction of the inner housing.

According to an embodiment related to the present invention, the outer housing may include: a plurality of heat exchange cells extending in a longitudinal direction inside the outer housing; A plurality of partition walls provided between the plurality of heat exchange cells to partition the plurality of heat exchange cells; And a plurality of communication passages formed at the front end or the rear end of each of the plurality of partition walls to communicate the plurality of heat exchange cells, thereby forming the first cooling passage.

According to an example related to the present invention, the plurality of partition walls protrude radially from the inner wall of the outer housing to be connected to the outer wall of the outer housing, and the plurality of communication flow paths of the outer housing along the circumferential direction It can be formed alternately at the front and rear ends.

According to an embodiment related to the present invention, the inner housing may include a plurality of flow path forming parts extending in a circumferential direction inside the inner housing; A flow path guide spaced apart from the plurality of flow path forming parts in a circumferential direction and extending along a length direction of the inner housing; And a common header provided between the plurality of flow path forming units and the flow path guide to distribute cooling water to the second cooling flow path or to collect the second cooling flow path from the second cooling flow path. It can be formed between the formation.

According to an example related to the present invention, the plurality of flow path forming parts protrude radially outward from the inner wall of the inner housing, and the outer ends of each of the plurality of flow path forming parts contact the inner wall of the outer housing. The inner housing may be press-fit to the inside of the outer housing.

According to another embodiment of the present invention, the outer housing may include: a plurality of flow path forming parts extending in a circumferential direction inside the outer housing to form a plurality of first cooling passages; A flow path guide spaced apart from the plurality of flow path forming parts in a circumferential direction and extending along a length direction of the outer housing; And a common header provided between the plurality of flow path forming parts and the flow path guide to distribute cooling water to the second cooling flow path or to collect the cooling water from the second cooling flow path.

According to another embodiment related to the present invention, the inner housing may include: a plurality of heat exchange cells extending along a length direction in the inner housing; A plurality of partition walls provided between the plurality of heat exchange cells to partition the plurality of heat exchange cells; And a plurality of communication passages formed at front or rear ends of each of the plurality of partition walls to communicate the plurality of heat exchange cells, thereby forming the second cooling passage.

According to an example related to the present disclosure, each of the plurality of injection holes may extend radially in the upper portion of the inner housing to inject oil into the stator coils.

According to an example related to the present invention, the plurality of injection holes may be disposed at the front end and the rear end in the longitudinal direction of the inner housing, respectively.

According to an example related to the present disclosure, the outer housing may include a cell outlet configured to communicate the first cooling passage with the plurality of injection holes.

According to an embodiment related to the present invention, an oil inlet formed on a bottom surface of the inner housing; And an oil pump mounted to one side of the outer housing to pump oil introduced through the oil inlet to the plurality of injection holes.

According to an example related to the present invention, the outer housing includes: a first semicircular portion disposed in one side section along a circumferential direction; And a second semicircular portion disposed in the other section along the circumferential direction and having a diameter larger than that of the first semicircular portion to form the first cooling passage therein.

According to an example related to the present disclosure, the outer housing may include: a cooling water inlet formed at an upper portion of the first semicircular portion; And a cooling water outlet formed at a lower position along the circumferential direction from the cooling water inlet.

Referring to the effect of the electric motor according to the invention as follows.

First, by directly cooling the motor with a plurality of injection holes for directly injecting oil from the upper portion of the housing to the stator coil, it is possible to improve the cooling efficiency and cooling performance.

Second, a first cooling passage disposed outside the housing and flowing oil and a second cooling passage disposed inside the housing and flowing coolant and heat-exchangable with the first cooling passage, so that the oil can be delivered to the injection hole in the upper portion of the housing. By cooling by the coolant while flowing along the first cooling passage, an additional heat exchange system for oil and heat exchange is not required outside the motor housing, thereby reducing the cost of the motor and contributing to the miniaturization of the motor.

Third, by having a complex cooling flow path structure in which oil cooling and water cooling are performed at the same time, the heat dissipation performance can be further improved to produce a higher output, which can be used to cool a motor for driving a vehicle of 50 kW or more. In addition, the size of the motor can be reduced while maintaining the same output of the motor.

Fourth, the complex cooling flow path is provided in the motor housing, so that the contact area through which the oil flow path and the cooling water flow path can exchange heat with each other increases, thereby increasing the heat dissipation performance of the motor.

Fifth, since the oil pump and the motor housing are integrally combined, the motor can be miniaturized, thereby increasing the design freedom when the motor is mounted in the vehicle.

Sixth, the inside and outside of the motor housing is composed of 2pieces has the advantage of easy molding of the dual cooling flow path.

Seventh, the internal flow path of the motor is provided with a multi-pass (MULTI-PASS) flow path structure, it is possible to smoothly maintain the flow in the circumferential direction to minimize the flow resistance.

1 is a perspective view showing a drive system according to the present invention.
FIG. 2 is a perspective view illustrating the motor housing in FIG. 1. FIG.
FIG. 3 is an exploded view illustrating a state in which the outer housing and the inner housing are disassembled in FIG. 2.
4 is a cross-sectional view taken along IV-IV in FIG. 2.
FIG. 5 is a cross-sectional view taken along VV in FIG. 2.
FIG. 6 is a conceptual view illustrating a movement path of oil flowing along a first cooling passage inside the outer housing in FIG. 3.
FIG. 7 is a conceptual view illustrating a movement path of cooling water flowing along a second cooling passage inside the inner housing of FIG. 3.
8 is a cross-sectional view of a motor housing showing a dual cooling channel structure according to a second embodiment of the present invention.
9 is a cross-sectional view of a motor housing showing a dual cooling channel structure according to a third embodiment of the present invention.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings, and the same or similar components are denoted by the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted. The suffixes "module" and "unit" for components used in the following description are given or used in consideration of ease of specification, and do not have distinct meanings or roles from each other. In addition, in describing the embodiments disclosed herein, when it is determined that the detailed description of the related known technology may obscure the gist of the embodiments disclosed herein, the detailed description thereof will be omitted. In addition, the accompanying drawings are intended to facilitate understanding of the embodiments disclosed herein, but are not limited to the technical spirit disclosed herein by the accompanying drawings, all changes included in the spirit and scope of the present invention. It should be understood to include equivalents and substitutes.

Terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

Singular expressions include plural expressions unless the context clearly indicates otherwise.

In this application, the terms "comprises" or "having" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

1 is a perspective view showing a drive system 1 according to the present invention, FIG. 2 is a perspective view showing a motor housing 100 in FIG. 1, and FIG. 3 is an outer housing 110 and an inner housing 120 in FIG. 2. Figure 4 is an exploded view showing the decomposition state, Figure 4 is a cross-sectional view taken along IV-IV in FIG.

5 is a cross-sectional view taken along VV in FIG. 2, and FIG. 6 is a conceptual view illustrating a movement path of oil flowing along the first cooling passage 114 inside the outer housing 110 in FIG. 3. 3 is a conceptual diagram illustrating a movement path of the coolant flowing along the second cooling passage 124 inside the inner housing 120.

The electric motor 10 according to the present invention can be applied to an electric vehicle or a hybrid vehicle. The electric motor 10 may provide a driving force for driving the driving wheel of the vehicle.

The drive system 1 according to the present invention comprises an electric motor 10 and an inverter 20 for driving the electric motor 10.

The electric motor 10 includes a motor housing 100. The stator and the rotor may be provided in the motor housing 100. The stator includes a stator core and a stator coil wound around the stator core.

The rotor is provided inside the stator core, and may be rotatably installed with respect to the stator. A rotating shaft is provided inside the rotor, and the rotor may be rotatably provided with the rotating shaft.

Motor housing 100 may be configured cylindrical to accommodate the stator and rotor. The motor housing 100 may be open in both directions along the axial direction. The motor housing 100 may include a plurality of fastening portions 129 at the front end and the rear end, respectively.

The rear cover 130 may be fastened to the rear end of the motor housing 100 to cover the rear of the motor housing 100. The rear cover 130 is configured to cover the rear of the motor housing 100 in the form of a plate, and a plurality of fastening portions 129 may be formed to be fastened to the motor housing 100.

The inverter 20 includes a cylindrical inverter housing 21 for accommodating an electronic component for driving the electric motor 10 therein. The inverter housing 21 may be fastened to the front end of the motor housing 100.

The inverter housing 21 is configured to extend in the axial direction at the front end of the motor housing 100, a plurality of fastening portions 129 protruding radially outward from the front end and the rear end of the inverter housing 21, respectively It may be provided. The plurality of fastening parts 129 may be spaced apart along the circumferential direction.

The front cover 22 may be fastened to the front end of the inverter housing 21 to cover the front of the inverter housing 21. The front cover 22 may be configured in the form of a circular plate. A plurality of fastening portions 129 protruding along the radial direction from the outer circumferential surface of the front cover 22 may be provided.

Each of the front cover 22, the inverter housing 21, the motor housing 100, and the rear cover 130 may be fastened with bolts through fastening holes formed in the plurality of fastening parts 129.

The motor housing 100 may have a dual cooling flow path. Each of the dual cooling passages may be configured to flow different fluids. One of the dual cooling paths can be configured to allow oil to flow. The other of the dual cooling passages can be configured to allow the cooling water to flow.

The motor housing 100 may be configured of the outer housing 110 and the inner housing 120.

The outer housing 110 may be formed in a cylindrical shape having a hollow portion therein.

The outer housing 110 may include a first cooling passage 114 through which oil flows.

To this end, when looking at the motor housing 100 in the axial direction in front of the motor housing 100 in which the incover housing is located, the left semicircle 113 and the right semicircle 111 have the same inner diameter and different outer diameters. Can be. Each of the left semicircle portion 113 and the right semicircle portion 111 may have the same diameter along the longitudinal direction.

Upper ends of each of the left semicircle portion 113 and the right semicircle portion 111 may be stepped in the radial direction. Lower ends of each of the left semicircle 113 and the right semicircle 111 may be stepped in the radial direction.

The right semicircle 111 of the outer housing 110 may be formed to extend outward more along the radial direction than the left semicircle 113.

The left semicircle 113 and the right semicircle 111 may have different circumferences. The right semicircle 111 extending radially may have a circumference longer or shorter than the left semicircle 113.

The first cooling passage 114 may be provided in the right semicircle 111 extending radially outward.

An oil inlet for injecting oil into the first cooling passage 114 may be formed at an upper end of the right semicircular portion 111. The oil stopper 1111 may be detachably mounted to block the oil inlet.

The first cooling passage 114 may form a passage for circulating oil.

The first cooling passage 114 may include a plurality of heat exchange cells 115. The plurality of heat exchange cells 115 may be spaced apart along the circumferential direction of the outer housing 110. Each of the plurality of heat exchange cells 115 may extend along the longitudinal direction of the outer housing 110.

The plurality of heat exchange cells 115 may be partitioned by a plurality of partition walls 116 extending along the radial direction. Each of the plurality of partitions 116 may extend along the longitudinal direction of the outer housing 110.

The right semicircular portion 111 is further provided with a communication passage 117 for connecting the heat exchange cells 115 adjacent to each other in the circumferential direction, the plurality of heat exchange cells 115 is one first cooling passage 114 Can be formed.

Each of the plurality of partitions 116 may have a shorter length in the axial direction than the plurality of heat exchange cells 115, so that two heat exchange cells 115 adjacent in the circumferential direction may be connected to each other.

Each of the plurality of communication passages 117 may be formed between the front end or the rear end of the plurality of heat exchange cells 115 and one end of the partition wall 116, respectively.

Each of the plurality of communication passages 117 may be alternately arranged at the front and rear ends of the plurality of heat exchange cells 115 along the circumferential direction.

The rear cover 130 may be coupled to cover rear ends of the plurality of heat exchange cells 115. The rear cover 130 may be selectively contacted with the rear ends of each of the plurality of partitions 116 alternately along the circumferential direction.

The rear end of the inverter housing 21 may be coupled to cover the front end of the plurality of heat exchange cells 115. The rear end of the inverter housing 21 may be selectively in contact with the front end of each of the plurality of partitions 116 alternately along the circumferential direction.

The plurality of heat exchange cells 115 may guide the flow direction of the oil together with the partition wall 116 to flow in opposite directions along the longitudinal direction of the outer housing 110.

The plurality of communication passages 117 may guide the flow direction of the oil to flow along the circumferential direction.

The plurality of heat exchange cells 115 may include first to fifth heat exchange cells 1155 disposed in the circumferential direction from the lower end of the right semicircular part 111 toward the upper end.

The first heat exchange cell 1151 may have a cell inlet 1151a in communication with the oil pump 112. The cell inlet may be connected in communication with the pump outlet of the oil pump 112.

An oil inlet 123 is formed on the bottom of the inner housing 120.

The oil pump 112 may be detachably mounted to the lower right side of the motor housing 100. The oil pump 112 may be configured as an electric pump driven by electric energy.

The pump mounting unit 1112 may protrude from the lower side of the right semicircle 111 of the outer housing 110. A pump discharge port may be formed inside the pump mounting unit 1112. A pump inlet may be formed at the bottom of the pump mounting unit 1112.

The pump inlet is connected to the oil inlet 123 by a connection hose 1113.

The oil pump 112 may include a pump housing 1121, a pumping blade and a pumping motor.

A plurality of coupling parts may be formed at four corners of the pump housing 1121, a plurality of coupling parts may be formed at four corners of the pump mounting part 1112, and coupling holes may be formed in the plurality of coupling parts, respectively. The pump housing 1121 may be screwed with the pump mounting unit 1112 with a plurality of screws.

The pumping blade is rotatably installed in the pump housing 1121, and pumps oil introduced into the pump housing 1121 through the pump inlet to discharge the inside of the heat exchange cell 115 through the pump outlet. have.

When the pumping motor is operated, the oil pump 112 sucks oil through the oil inlet 123 and flows into the pump housing 1121, and then pumps oil through the rotation of the pumping blades through the cell inlet 1151a. It can discharge into the inside of the 1st heat exchange cell 1151.

Referring to FIG. 5, the oil introduced through the cell inlet 1151a is first heat exchanged cells 1151 to 5th heat exchange cell along the counterclockwise direction (upward from bottom in FIG. 5) by the oil pump 112. (1155) It moves to order. Each of the plurality of heat exchange cells 115 moves in a zigzag form along the longitudinal direction (left and right direction in FIG. 5) of the motor housing 100.

After moving to the fifth heat exchange cell 1155, the cell may be discharged to the inside of the upper portion of the inner housing 120 through a plurality of cell outlet holes formed on the bottom surface of the fifth heat exchange cell 1155. The plurality of cell outlet holes may be spaced apart from each other in the front and rear directions (left and right directions in FIG. 5) of the fifth heat exchange cell 1155, and may be formed in communication with the inner side of the inner housing 120.

In the present embodiment, the first cooling passage 114 shows a single configuration.

Meanwhile, in another embodiment, a plurality of first cooling passages 114 may be formed in each of the front and rear portions of the outer housing 110 along the longitudinal direction of the motor housing 100. The plurality of first cooling passages 114 may be partitioned by partition walls 116 extending along the circumferential direction.

In this case, a communication hole is formed in the partition wall 116 that traverses the first heat exchange cell 1151 along the circumferential direction, so that the oil moves from the second half of the first heat exchange cell 1151 to the first half through the communication hole. In both directions along the circumferential direction, up to the fifth heat exchange cell 1155 may be zigzag-shaped, and oil may flow out through the cell outlet holes formed in each of the first half and the second half of the fifth heat exchange cell 1155.

The inner housing 120 may be pressed into and coupled to the inner circumferential surface of the outer housing 110.

The inner housing 120 may have a cylindrical shape having a hollow portion therein. The inner housing 120 may be formed to be open in the axial direction. The inner housing 120 may have an outer diameter equal to the inner diameter of the inner housing 120.

The stator and the rotor may be disposed in the hollow portion of the inner housing 120. The stator core may be pressed into the inner housing 120 to be coupled.

A plurality of second cooling passages 124 may be provided in the inner housing 120.

The plurality of second cooling passages 124 may extend in a direction crossing the first cooling passage 114.

Each of the plurality of second cooling passages 124 may be formed to extend in the circumferential direction.

The plurality of second cooling passages 124 may be spaced apart along the longitudinal direction of the inner housing 120. The plurality of second cooling passages 124 may be partitioned by the plurality of flow path forming units 125.

Each of the plurality of flow path forming portions 125 may protrude radially outward from the outer circumference of the inner housing 120, so that each of the plurality of second cooling passages 124 may be opened radially outward of the inner housing 120. . The opened portions of the plurality of second cooling passages 124 may be covered by the inner walls of the outer housing 110 to guide the flow direction of the coolant along the circumferential direction.

Each of the plurality of flow path forming portions 125 may extend along the circumferential direction. The plurality of flow path forming parts 125 may have an outer diameter equal to the inner diameter of the outer housing 110 and may be press-fitted to the inside of the outer housing 110.

According to this configuration, the outer housing 110 and the inner housing 120 do not have an inner wall of the first cooling passage 114 and an outer wall of the second cooling passage 124 to overlap each other in a radial direction. By sharing the boundary wall, the radial thickness of the motor housing 100 may be reduced, and the thickness of the boundary wall may be reduced, thereby minimizing heat loss during heat exchange between water and oil, and improving heat exchange efficiency.

A plurality of O-rings 1251 grooves may be formed at the front and rear ends of the inner housing 120. O-rings (1251) are installed in each of the O-ring (1251) grooves, the O-ring (1251) can maintain the watertight between the inner housing 120 and the outer housing (110).

An end ring portion 121 may be further provided at a front end or a rear end of the inner housing 120. The end ring portion 121 may have the same outer diameter and diameter of the outer housing 110. The end ring 121 may protrude radially outward from the outer circumference of the inner housing 120, and may be provided to cover open front or rear ends of the plurality of heat exchange cells 115.

A bridge 126 may extend along the longitudinal direction at the center of the upper end of the inner housing 120. The bridge 126 may protrude radially outward from the outer circumference of the inner housing 120. Injection holes 1261 may be radially penetrated through the front end and the rear end of the bridge 126, respectively.

The injection hole 1261 may have an upper end connected in communication with the cell outlet 1155a, and a lower end communicated with an inner side of the inner housing 120. The outlet (lower end) of the injection hole 1261 may be configured to face the end turn of the stator coil.

The end turn refers to both ends of the stator coil protruding from the slot of the stator core, and is formed in a structure bent in the opposite direction so that the coil segments (for example, the bent portion of the hairpin) are wound toward the next slot at both ends of the stator coil. do.

The coolant inlet 1131 and the coolant outlet 1132 may be formed at the left semicircle 113 of the outer housing 110. Cooling water may be introduced into the second cooling channel 124 through the cooling water inlet 1131. Cooling water may flow out of the second cooling channel 124 to the outside of the motor housing 100 through the cooling water outlet 1132.

The coolant inlet 1131 and the coolant outlet 1132 may be connected to a coolant cooling system.

The coolant cooling system can be connected to the radiator of the vehicle. The radiator is a device that emits heat generated by the vehicle by contacting air outside the vehicle. For example, the radiator may be disposed in front of the vehicle so that outside air may flow into the radiator when the vehicle is driven.

The radiator includes a heat exchanger tube configured to allow the coolant to flow therein, such that the outside air and the coolant may be heat exchanged through the heat exchanger tube.

The cooling water cooling system further includes a radiator, a cooling water connection pipe connecting the cooling water inlet 1131 and the cooling water outlet 1132, and a circulation pump for circulating the cooling water, so that the cooling water discharged from the cooling water outlet 1132 is discharged from the radiator. After dissipating heat, it may again flow into the second cooling channel 124 through the cooling water inlet 1131.

The coolant inlet 1131 and the coolant outlet 1132 should be partitioned from each other in the second cooling passage 124 formed along the circumferential direction. This is to prevent the coolant introduced into the coolant inlet 1131 from flowing out to the coolant outlet 1132 without heat exchange.

The coolant inlet 1131 and the coolant outlet 1132 may be spaced apart from each other along the circumferential direction of the motor housing 100. The flow guide 127 spaced counterclockwise from the bridge 126 of the inner housing 120 extends along the longitudinal direction of the inner housing 120 to cross between the coolant inlet 1131 and the coolant outlet 1132. Can be.

The flow guide 127 may protrude radially outward from the outer circumference of the inner housing 120 to be in contact with the inner surface of the left semicircle 113 of the outer housing 110. The flow guide 127 may prevent the coolant flowing through the coolant inlet 1131 from directly moving to the coolant outlet 1132, and prevent the coolant outlet 1132 from flowing out without the heat exchange.

That is, the cooling water introduced through the cooling water inlet 1131 is configured to rotate in a clockwise direction along the second cooling water channel.

A connection hole 1262 is formed through the lower portion of the bridge 126 in the circumferential direction, such that the cooling water inlet 1131 and the second cooling passage 124 may communicate with each other through the connection hole 1262. The connection hole 1262 may extend along the longitudinal direction of the bridge 126.

An inlet side common header 1281 may be formed between the flow guide 127 and one end of the second cooling passage 124 (spaced apart clockwise from the bridge 126). The inlet side common header 1281 is configured to distribute the coolant introduced through the coolant inlet 1131 to the plurality of second cooling passages 124.

The inflow common header 1281 may be formed on the left side and the right side with the bridge 126 interposed therebetween. The two inlet-side common headers 1281 respectively formed on the left and right sides are communicated by the connection holes 1262 and are movable from the left to the right through the connection holes 1262 with the cooling water.

An outlet side common header 1282 may be formed between the flow guide 127 and the other end of the second cooling flow passage 124 (spaced counterclockwise from the flow guide 127). The outlet side common header 1282 is configured to collect the coolant moving in the clockwise direction along the second cooling channel 124 and to discharge it to the coolant outlet 1132.

The inlet side common header 1281 and the outlet side common header 1282 may extend along the longitudinal direction of the inner housing 120.

The operation of the cooling system of the electric motor 10 by such a configuration will be described.

In this embodiment, a direct cooling method using oil and an indirect cooling method using cooling water may be applied in combination.

Referring first to the direct cooling method by the oil with reference to Figure 5, the oil is supplied with a circulating power from the oil pump 112, the first heat exchange cell (located at the bottom of the outer housing 110 through the cell inlet 1151a ( 1151).

The oil moves from the rear end (right end in the drawing) of the outer housing 110 toward the front (left side in the drawing) by the first partition walls 1161 and 116 in the first heat exchange cell 1151, and the first The first communication flow path 1171 formed at the front end of the heat exchange cell 1151 may move to the second heat exchange cell 1152 positioned second from the bottom in the counterclockwise direction.

The oil is moved from the front end of the outer housing 110 to the rear by the second partitions 1162 and 116 in the second heat exchange cell 1152 and formed at the rear end of the second heat exchange cell 1152. The second communication flow path 1172 may move to the third heat exchange cell 1153 located at the third from the bottom in the counterclockwise direction.

Subsequently, the oil moves forward from the rear end of the outer housing 110 by the third partitions 1163 and 116 in the third heat exchange cell 1153, and the front end portion of the third heat exchange cell 1153. It may move to the fourth heat exchange cell (1154) located fourth from the bottom in the counterclockwise direction through the third communication passage (1173) formed in the.

Subsequently, the oil is moved toward the rear of the outer housing 110 by the fourth partitions 1164 and 116 in the fourth heat exchange cell 1154, and the oil is formed at the rear end of the fourth heat exchange cell 1154. It may move to the fifth heat exchange cell 1155 located at the top counterclockwise through the four communication passage 1174.

Subsequently, the oil flows downward through the cell outlet 1155a in the fifth heat exchange cell 1155 and flows into the inner space of the inner housing 120 through the injection hole 1261 in communication with the cell outlet 1155a. It can be injected directly to the end turn of the stator coil.

The oil injected into the end turn can directly cool the stator and the rotor by wetting not only the stator coil but also the stator core, the rotor, and the rotating shaft around the stator coil.

By spraying oil directly onto the stator coils, cooling efficiency and cooling performance can be improved.

The oil may be cooled by the coolant while moving in a zigzag form along the front and rear directions of the motor housing 100 until reaching the fifth heat exchange cell 1155 from the first heat exchange cell 1151.

According to this, the oil can be cooled by the coolant to absorb more heat from the motor housing 100. The motor housing 100 may be in contact with the outer circumferential portion of the stator core.

That is, the inner circumferential surface of the inner housing 120 is in contact with the outer circumferential portion of the stator core, and the flow path forming portion 125, the flow guide 127, the bridge 126, and the like of the inner housing 120 are disposed in the outer housing 110. In contact with the side wall, heat generated in the stator core is transferred from the inner wall of the inner housing 120 to the outer housing 110 through the flow path forming portion 125, the flow guide 127, and the bridge 126. Heat may be transferred from the housing 110 to oil.

In FIG. 6, the coolant introduced into the inlet common header 1281 through the coolant inlet 1131 may be moved along the front and rear directions of the inner housing 120 by the flow guide 127 in the inlet common header 1281. have.

Subsequently, the coolant may receive power from the coolant circulation pump, move clockwise to pass through the connection hole 1262, and may be distributed to the plurality of second cooling passages 124 by the plurality of flow path forming units 125.

Subsequently, the coolant moves clockwise along the plurality of second cooling passages 124, passes through the lower end of the inner housing, and moves to the outlet common header 1242 located at the upper end of the second cooling passage 124. Is collected.

The coolant collected in the outlet common header 1282 is passed through the coolant outlet 1132 located in the middle along the axial direction of the inner housing 120 along the front and rear directions of the inner housing 120 by the flow guide 127. May spill.

The coolant exchanges heat with the oil flowing along the first cooling channel 114 of the outer housing 110 while flowing along the second cooling channel 124 of the inner housing 120.

The cooling water flows in a direction crossing the flow direction of the oil, thereby improving heat exchange performance of the cooling water and the oil.

Depending on the temperature difference between the coolant and the oil, heat transfer can be made from the oil to the coolant. The coolant may be cooled by heat exchange with air in the radiator and then returned to the motor housing 100.

Therefore, according to the present invention, the cooling efficiency and the cooling performance can be improved by directly cooling the motor with a plurality of injection holes for directly injecting oil from the upper portion of the housing to the stator coil.

In addition, the oil is provided with a first cooling passage 114 disposed outside the housing and in which oil flows, and a second cooling passage 124 disposed inside the housing and in which cooling water flows and heat exchanged with the first cooling passage 114. Cooled by the coolant while flowing along the first cooling passage 114 until it is delivered to the injection hole in the upper portion of the housing, the external flow path of the heat exchange system for heat exchange with oil is not necessary, thereby simplifying the structure of the cooling system of the motor. have.

In addition, by having a complex cooling flow path structure in which oil cooling and water cooling are performed at the same time, the cooling performance can be further increased to be used to cool a motor for driving a vehicle of 50 kW or more.

In addition, since the oil pump 112 and the motor housing 100 are integrally coupled, the motor can be miniaturized, thereby increasing the design freedom when the motor is mounted in the vehicle.

In addition, the inside and outside of the motor housing 100 is composed of 2pieces has the advantage of easy molding of the dual cooling flow path.

In addition, by providing a multi-pass (MULTI-PASS) flow path structure of the motor internal flow path, it is possible to smoothly maintain the flow in the circumferential direction to minimize the flow resistance.

8 is a cross-sectional view of the motor housing 200 showing the structure of the dual cooling flow path according to the second embodiment of the present invention.

The motor housing 200 according to the second embodiment may be composed of an outer housing 210 and an inner housing 220. The dual cooling passages may include a plurality of first cooling passages 214 formed in the outer housing 210 and second cooling passages formed in the inner housing 220.

Each of the plurality of first cooling passages 214 extends in the circumferential direction inside the outer housing 210, and the plurality of first cooling passages 214 are formed of the outer housing 210 by the plurality of flow path forming portions 2151. It may be spaced apart along the longitudinal direction of the).

The second cooling passage may be formed with a plurality of heat exchange cells 225 extending in the longitudinal direction in the inner housing 220 and a plurality of communication passages connecting the plurality of heat exchange cells 225.

The plurality of communication passages may be alternately formed at the front end and the rear end of the inner housing 220 while moving along the circumferential direction.

The oil may be driven from the oil pump to move in the circumferential direction along the plurality of first cooling passages 214 toward the upper end from the lower end of the outer housing 210.

The coolant may move in a zigzag form along the second cooling passage along the second cooling passage in the upper portion of the inner housing 220 by receiving power from the circulation pump. The cooling water may move between the plurality of heat exchange cells 225 adjacent in the circumferential direction through the plurality of communication passages.

The oil flows along the first cooling passage 214 of the outer housing 210, and the coolant flows along the second cooling passage of the inner housing 220 and may be heat-exchanged with each other.

Since other components are the same as or similar to the above-described first embodiment (see FIGS. 1 to 6), redundant descriptions will be omitted.

9 is a cross-sectional view of the motor housing 300 showing the structure of the dual cooling channel according to the third embodiment of the present invention.

The motor housing 300 according to the third embodiment may be composed of an outer housing 310 and an inner housing 320.

The dual cooling passages may include a plurality of first cooling passages 314 formed in the outer housing 310 and a second cooling passage 324 formed in the inner housing 320.

Each of the plurality of first cooling passages 314 extends in the circumferential direction inside the outer housing 310, and the plurality of first cooling passages 314 are formed by the plurality of flow path forming portions 3151. It may be spaced apart along the longitudinal direction of the).

The plurality of second cooling passages 324 may also be configured in the same manner as the plurality of first cooling passages 314.

The plurality of first and second cooling passages 324 are formed to be open inward or outward in the same direction, for example, in a radial direction, and are disposed between the outer housing 310 and the inner housing 320. 330 may be fitted.

The intermediate housing 330 is configured to block an open portion of the first cooling passage 314 or the second cooling passage 324 to prevent the oil and the cooling water from mixing with each other. The intermediate housing 330 may be configured in the form of a cylindrical tube having a hollow therein.

The oil may flow along the first cooling passage 314 of the outer housing 310, and the coolant may flow along the second cooling passage 324 of the inner housing 320 and may exchange heat with each other.

In the above-described embodiment, the oil flows along the first cooling passage 314 inside the outer housing 310, and the cooling water flows along the second cooling passage 324 inside the inner housing 320. Although described, on the contrary, the coolant may be configured to flow inside the outer housing 310 and to flow oil into the inner housing 320.

First embodiment
1: drive system 10: electric motor
100: motor housing 110: outer housing
111: right semicircle 1111: oil stopper
1112: pump mounting portion 1113: connection hose
112: oil pump 1121: pump housing
113: left semicircle 1131: cooling water inlet
1132: cooling water outlet 114: the first cooling passage
115: heat exchange cell 1151: first heat exchange cell
1151a: cell inlet 1152: second heat exchange cell
1153: third heat exchange cell 1154: fourth heat exchange cell
1155: fifth heat exchange cell 1155a: cell outlet
116: partition 1161: the first partition
1162: second bulkhead 1163: third bulkhead
1164: fourth bulkhead 117: communication flow path
1171: first communication path 1172: second communication path
1173: third communication channel 1174: fourth communication channel
120: inner housing 121: end ring portion
123: oil inlet 124: second cooling flow path
125: flow path forming portion 1251: O-ring
126: bridge 1261: injection hole
1262: connecting hole 127: euro guide
1281: Common header on the inflow side 1282: Common header on the outlet side
129: fastening portion 130: rear cover
20: inverter 21: inverter housing
22: front cover
Second embodiment
200: motor housing 210: outer housing
214: first cooling passage 2151: flow path forming portion
220: inner housing 225: heat exchange cell
Third embodiment
300: motor housing 310: outer housing
314: first cooling passage 3151: flow path forming portion
320: inner housing 324: second cooling flow path
3251: flow path forming portion 330: intermediate housing

Claims (15)

Motor housing;
A stator having a stator coil and disposed inside the motor housing;
It includes a rotor rotatably installed inside the stator,
The motor housing,
An outer housing having a first cooling passage through which oil flows;
An inner housing disposed inside the outer housing and having a second cooling passage through which coolant flows to exchange heat with the first cooling passage; And
A plurality of injection holes formed in the inner housing in communication with the first cooling flow path and injecting the oil into the inner housing;
The inner housing is
A plurality of flow path forming portions extending in a circumferential direction inside the inner housing;
A flow path guide spaced apart from the plurality of flow path forming parts in a circumferential direction and extending along a length direction of the inner housing; And
A common header provided between the plurality of flow path forming parts and the flow path guide to distribute cooling water to the second cooling flow path or to collect the cooling water from the second cooling flow path,
The second cooling passage is formed between the plurality of flow path forming unit. The method of claim 1,
And the first cooling passage and the second cooling passage extend in a direction crossing each other. The method of claim 1,
And the first cooling passage extends in the longitudinal direction of the outer housing, and the second cooling passage extends in the circumferential direction of the inner housing. The method of claim 1,
The outer housing,
A plurality of heat exchange cells extending in a longitudinal direction in the outer housing;
A plurality of partition walls provided between the plurality of heat exchange cells to partition the plurality of heat exchange cells; And
And a plurality of communication flow paths formed at the front end or the rear end of each of the plurality of partition walls to communicate the plurality of heat exchange cells, thereby forming the first cooling flow path. The method of claim 4, wherein
The plurality of partition walls protrude radially from the inner wall of the outer housing is connected to the outer wall of the outer housing,
And the plurality of communication passages are alternately formed at the front and rear ends of the outer housing along the circumferential direction. delete The method of claim 1,
The plurality of flow path forming portions protrude radially outward from the inner wall of the inner housing,
And the inner housing is press-fitted to the inside of the outer housing such that the outer ends of each of the plurality of flow path forming parts contact the inner wall of the outer housing. Motor housing;
A stator having a stator coil and disposed inside the motor housing;
It includes a rotor rotatably installed inside the stator,
The motor housing,
An outer housing having a first cooling passage through which oil flows;
An inner housing disposed inside the outer housing and having a second cooling passage through which coolant flows to exchange heat with the first cooling passage; And
A plurality of injection holes formed in the inner housing in communication with the first cooling flow path and injecting the oil into the inner housing;
The outer housing,
A plurality of flow path forming portions extending in a circumferential direction inside the outer housing to form a plurality of first cooling passages;
A flow path guide spaced apart from the plurality of flow path forming parts in a circumferential direction and extending along a length direction of the outer housing; And
And a common header provided between the plurality of flow path forming units and the flow path guide to distribute cooling water to the second cooling flow path or to collect the cooling water from the second cooling flow path. The method of claim 8,
The inner housing is
A plurality of heat exchange cells extending in a longitudinal direction in the inner housing;
A plurality of partition walls provided between the plurality of heat exchange cells to partition the plurality of heat exchange cells; And
And a plurality of communication passages formed at the front end or the rear end of each of the plurality of partition walls to communicate the plurality of heat exchange cells to form the second cooling passage. The method of claim 1,
Each of the plurality of injection holes extend in the radial direction on the inner upper portion of the inner housing, characterized in that for spraying the oil to the stator coil. The method of claim 10,
The plurality of injection holes are disposed in the front end and the rear end in the longitudinal direction of the inner housing, respectively. The method of claim 10,
The outer housing includes a cell outlet for communicating the first cooling passage and the plurality of injection holes. The method of claim 10,
An oil inlet formed on a bottom surface of the inner housing; And
And an oil pump mounted to one side of the outer housing and configured to pump oil introduced through the oil inlet to the plurality of injection holes. Motor housing;
A stator having a stator coil and disposed inside the motor housing;
It includes a rotor rotatably installed inside the stator,
The motor housing,
An outer housing having a first cooling passage through which oil flows;
An inner housing disposed inside the outer housing and having a second cooling passage through which coolant flows to exchange heat with the first cooling passage; And
A plurality of injection holes formed in the inner housing in communication with the first cooling flow path and injecting the oil into the inner housing;
The outer housing,
A first semicircular portion disposed in one section along the circumferential direction; And
And a second semicircular portion disposed in the other section along the circumferential direction and having a larger diameter than the first semicircular portion to form the first cooling passage therein. The method of claim 14,
The outer housing,
A cooling water inlet formed in an upper portion of the first semicircular portion; And
And a cooling water outlet formed at a lower position along the circumferential direction from the cooling water inlet.

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