JP7447623B2 - motor unit - Google Patents

Description

The present invention relates to a motor unit.

A conventional motor unit includes a motor and a housing (motor housing) that accommodates the motor. A cooling medium (liquid refrigerant) for cooling the motor is housed inside the housing. The motor has a rotor that rotates around a motor shaft. A pump (impeller) is attached to the rotor, and the impeller rotates in conjunction with the rotor. Thereby, the cooling medium circulates within the housing (see, for example, Japanese Patent Application Laid-Open No. 2009-71923).

Japanese Patent Application Publication No. 2009-71923

However, in the motor unit as described above, the pump is housed in a housing, and there is a problem in that maintenance workability is poor when the pump breaks down. Furthermore, there is a problem in that the temperature of the cooling medium circulating within the housing increases due to the heat of the pump, resulting in a decrease in the cooling performance of the motor.

SUMMARY OF THE INVENTION An object of the present invention is to provide a motor unit that can improve maintenance workability and improve motor cooling performance.

An exemplary motor unit of the present invention includes a motor, a housing, a refrigerant flow path, a pump, and a cooler. The motor includes a rotor that rotates around a motor shaft, and a stator that faces the rotor in a radial direction with a gap therebetween. The cylindrical housing has a motor chamber that accommodates the motor and a cooling medium that cools the motor. The coolant flow path is arranged outside the motor room, and the coolant flows therethrough. The pump circulates the cooling medium. The cooler cools the cooling medium. The refrigerant flow path is formed to extend in the circumferential direction and communicates with an inlet and an outlet that open facing the motor chamber. A pump and cooler are provided in the refrigerant flow path.

According to the exemplary embodiments of the present invention, it is possible to provide a motor unit that can improve workability in the event of a failure and can also improve cooling performance.

FIG. 1 is a perspective view of a motor unit according to a first embodiment of the present invention. FIG. 2 is a schematic configuration diagram schematically showing the internal configuration of the motor unit according to the first embodiment of the present invention. FIG. 3 is a perspective view of a motor unit according to a second embodiment of the invention. FIG. 4 is a schematic configuration diagram schematically showing the internal configuration of a motor unit according to a second embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. Note that in this specification, the vertical direction will be defined and explained based on the positional relationship when the motor unit 1 is mounted on a vehicle located on a horizontal road surface. In addition, in the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction is a vertical direction with the +Z side as the upper side and the -Z side as the lower side. The X-axis direction is a direction perpendicular to the Z-axis direction, and is the front-rear direction of the vehicle in which the motor unit 1 is mounted. In this embodiment, the +X side is the front side of the vehicle, and the -X side is the rear side of the vehicle. The Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction, and is the left-right direction of the vehicle. In this embodiment, the +Y side is the left side of the vehicle, and the -Y side is the right side of the vehicle.

Note that the positional relationship in the longitudinal direction is not limited to the positional relationship of this embodiment, and the +X side may be the rear side of the vehicle, and the -X side may be the front side of the vehicle. In this case, the +Y side is the right side of the vehicle and the -Y side is the left side of the vehicle.

A motor shaft J1 appropriately shown in each figure extends in the Y-axis direction, that is, in the left-right direction of the vehicle. In the following description, unless otherwise specified, the direction parallel to the motor shaft J1 is simply referred to as the "axial direction", the radial direction centered on the motor shaft J1 is simply referred to as the "radial direction", and the direction parallel to the motor shaft J1 is simply referred to as the "radial direction". The circumferential direction around the center, that is, the circumferential direction around the motor shaft J1 is simply referred to as the "circumferential direction." Note that in this specification, "parallel directions" include substantially parallel directions, and "orthogonal directions" include substantially orthogonal directions.

<First embodiment>
<1. Overall configuration of motor unit>
A motor unit 1 according to an exemplary embodiment of the present invention will be described below. FIG. 1 is a perspective view of a motor unit 1 according to an embodiment of the present invention, and FIG. 2 is a diagram schematically showing the internal configuration of the motor unit 1. As shown in FIG. The motor unit 1 includes a cylindrical housing 10, a refrigerant flow path 15, a motor 20, a pump 30, and a cooler 40.

<2. Housing configuration>
The housing 10 includes a circumferential wall portion 11 in the shape of a cylinder with a lid that extends in the axial direction and is closed on the left side, and a lid wall portion 12 that closes an opening on the right side of the circumferential wall portion 11. A motor chamber 10a is formed in a space surrounded by the peripheral wall portion 11 and the lid wall portion 12. That is, the housing 10 has a motor chamber 10a. The motor chamber 10a accommodates the motor 20 and oil (cooling medium) O.

The coolant flow path 15 is arranged outside the motor chamber 10a and extends in the circumferential direction. The refrigerant flow path 15 has an inlet 15a opened at one end and an outlet 15b opened at the other end. The inlet 15a and the outlet 15b are arranged on the peripheral wall 11 and open facing the motor chamber 10a. That is, the refrigerant flow path 15 is formed to extend in the circumferential direction, and communicates with the inlet 15a and the outlet 15b. The inlet 15a is arranged at the lower part of the motor chamber 10a, and the outlet 15b is arranged at the upper part of the motor chamber 10a. A plurality of outflow ports 15b are provided in line in the axial direction. The refrigerant flow path 15 will be explained in detail later.

<3. Motor configuration>
The motor 20 is an inner rotor type motor. The motor 20 includes a rotor 21 and a stator 22.

The rotor 21 rotates around a motor shaft J1 that extends in the horizontal direction. The rotor 21 has a shaft 211 and a rotor body 212. The rotor main body 212 includes a rotor core (not shown) and a rotor magnet (not shown) fixed to the rotor core. The shaft 211 extends in the axial direction centering on the motor shaft J1.

The shaft 211 is rotatably supported by bearings 23 and 24. Bearings 23 and 24 are held in housing 10. The bearings 23 and 24 are, for example, ball bearings.

The stator 22 faces the rotor 21 radially outward through a gap. Stator 22 includes a stator core 221 and a plurality of coils 222. Stator core 221 surrounds rotor 21 . Stator core 221 has a cylindrical core back (not shown) extending in the axial direction and a plurality of teeth (not shown) extending radially inward from the core back. The plurality of teeth are arranged at equal intervals all around the circumferential direction.

The plurality of coils 222 are respectively attached to each tooth of the stator core 221 via an insulator (not shown). The plurality of coils 222 are arranged along the circumferential direction.

<4. Oil passage configuration>
The housing 10 is provided with an oil passage 90. The oil path 90 is a path for oil O that circulates through the motor chamber 10a and the refrigerant flow path 15.

In addition, in this specification, "oil path" means the path of oil O. Therefore, the term "oil path" is a concept that includes not only a "flow path" that creates a constant flow of oil in one direction, but also a path where oil O is temporarily retained and a path where oil O drips. be. The path in which the oil O is temporarily stored includes, for example, a storage section P that stores the oil O.

Oil O is a cooling medium that cools the motor 20. As the oil O, in order to function as a lubricating oil and a cooling oil for the motor 20, it is preferable to use an oil equivalent to automatic transmission fluid (ATF), which has a relatively low viscosity.

<5. Configuration of refrigerant flow path>
Oil O flowing out from the lower part of the motor chamber 10a flows through the refrigerant flow path 15 and is supplied to the upper part of the motor chamber 10a. Pump 30 and cooler 40 are provided in refrigerant flow path 15 . Further, a reservoir P is provided between the inlet 15a on the refrigerant flow path 15 and the pump 30. In this embodiment, the reservoir P is made of the same member as the housing 10.

The refrigerant flow path 15 includes a first flow path 151 , a second flow path 152 , a third flow path 153 , a fourth flow path 154 , and a branch flow path portion 155 .

The first flow path 151 has an inlet 15a open at one end and extends downward from the inlet 15a. The first flow path 151 communicates the motor chamber 10a and the reservoir P.

The second flow path 152 communicates between the reservoir P and the pump 30. The third flow path 153 communicates between the pump 30 and the cooler 40. The fourth flow path 154 communicates between the cooler 40 and the branch flow path section 155. The second flow path 152, the third flow path 153, the fourth flow path 154, and the branch flow path portion 155 extend in the circumferential direction.

The reservoir P is arranged below the motor chamber 10a. The storage section P stores oil O that has flowed into the refrigerant flow path 15 from the motor chamber 10a through the inlet 15a. The reservoir P is provided with a filter (not shown). The filter collects foreign matter in the circulating oil O.

Pump 30 is an electric gear pump driven by electricity. Maintenance workability is improved by providing the pump 30 in the refrigerant flow path 15 arranged outside the motor chamber 10a. Further, the space around both axial ends of the shaft 211 protruding from the housing 10 is expanded. This improves the degree of freedom in designing the area around the shaft 211 of the motor unit 1.

The pump 30 has a pump chamber 31 and a gear 32. The pump chamber 31 has an open suction port 31a and a discharge port 31b, and accommodates a gear 32 therein. That is, the pump chamber 31 communicates the oil O suction port 31a and the oil O discharge port 31b. The gear 32 is housed in the pump chamber 31 and pumps the oil O by rotation. The suction port 31a is connected to the second flow path 152. The discharge port 31b is connected to the third flow path 153.

The rotation axis C of the gear 32 is arranged parallel to the motor axis J1 of the motor 20. The suction port 31a is arranged in the axial direction of the gear 32, and the discharge port 31b is arranged in the circumferential direction of the gear 32.

The rotation of the gear 32 forces the oil O from the suction port 31a to the discharge port 31b. By arranging the rotation axis C of the gear 32 parallel to the motor axis J1 of the motor 20, the oil O can be smoothly delivered to the refrigerant flow path 15, and the driving efficiency of the pump 30 can be improved.

The pump 30 sucks up the oil O from the reservoir P through the second flow path 152 and pumps the oil O through the third flow path 153 , the cooler 40 , the fourth flow path 154 , and the branch flow path section 155 . It is supplied into the motor chamber 10a. That is, the pump 30 circulates the oil (cooling medium) O.

The cooler 40 cools the oil O passing through the refrigerant flow path 15. The cooler 40 has a flow path 40a that allows the third flow path 153 and the fourth flow path 154 to communicate with each other. A plurality of cooling fins 40b are provided on the outer periphery of the flow path 40a. Heat is transferred from the flow path 40a to the fins 40b, allowing the oil O to be efficiently cooled. Therefore, the cooling performance of the motor 20 can be improved.

Note that the cooler 40 may be connected to a cooling water pipe through which cooling water cooled by a radiator (not shown) passes. In this case, the oil O passing through the flow path 40a provided inside the cooler 40 is cooled by heat exchange with the cooling water passing through the cooling water pipe.

The branch flow path section 155 is arranged above the motor chamber 10a. The branch passage section 155 branches the refrigerant passage 15 into a plurality of passages between the outlet 15b and the cooler 40, and each passage communicates with the plurality of outlets 15b arranged in the axial direction. That is, the refrigerant flow path 15 has a branch flow path section 155 that branches a plurality of flow paths between the outlet 15b and the cooler 40 and communicates with the outlet 15b.

The oil O that has flowed into the branch flow path portion 155 from the fourth flow path 154 is injected toward the rotor 21, stator 22, and bearings 23 and 24 from the outlet 15b. Oil O injected into the motor chamber 10a from the outlet 15b is dripped downward and flows into the refrigerant flow path 15 via the inlet 15a. At this time, the inlet 15a, the pump 30, the cooler 40, and the outlet 15b are arranged in order in the circumferential direction, so that the oil O can smoothly flow within the refrigerant flow path 15.

The motor unit 1 further includes a temperature sensor (not shown) that can detect the temperature of the motor 20. The type of temperature sensor is not particularly limited as long as it can detect the temperature of the motor 20. The motor unit 1 controls the drive of the pump 30 based on the detection result of the temperature sensor. For example, when the motor unit 1 determines that the temperature of the stator 22 is equal to or higher than a predetermined threshold based on the detection result of the temperature sensor, the motor unit 1 increases the output of the pump 30.

<Second embodiment>
Next, a second embodiment of the present invention will be described. FIG. 3 is a perspective view of the motor unit 1, and FIG. 4 is a diagram schematically showing the internal configuration of the motor unit 1. For convenience of explanation, the same parts as in the first embodiment shown in FIGS. 1 and 2 described above are given the same reference numerals. In the second embodiment, the reservoir P is not provided, and the configuration of the pump 30 is different from the first embodiment. Other parts are the same as those in the first embodiment.

The first flow path 151 directly connects the inlet 15a and the suction port 31a. At this time, since the reservoir P is provided within the pump chamber 31, the second flow path 152 is not provided. Further, the rotation axis C of the gear 32 is arranged to intersect with the motor axis J1 in a direction perpendicular to the motor axis J1. By providing the reservoir P within the pump chamber 31, the motor unit 1 can be downsized. Note that in the first embodiment, the inlet 15a and the suction port 31a may be directly connected.

<6. Others>
The embodiments of the present invention have been described above. Note that the scope of the present invention is not limited to the above-described embodiments. The present invention can be implemented with various modifications without departing from the spirit of the invention. Moreover, the above-mentioned embodiments can be combined arbitrarily as appropriate.

In this embodiment, the pump 30 and the cooler 40 are arranged side by side in the axial direction, but by bending a part of the refrigerant flow path 15 in the axial direction, the pump 30 and the cooler 40 are arranged side by side in the axial direction. It may be placed in By arranging the pump 30 and the cooler 40 side by side in the axial direction, the space below the motor unit 1 is expanded. This improves the degree of freedom in designing the lower part of the motor unit 1.

The present invention can be used, for example, in an electric vehicle (EV) (including a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHV), etc.) that has a motor unit and uses the motor as a power source.

1 Motor unit 10 Housing 10a Motor chamber 11 Peripheral wall 12 Lid wall 15 Refrigerant flow path 15a Inlet 15b Outlet 20 Motor 21 Rotor 22 Stator 23, 24 Bearing 30 Pump 31 Pump chamber 31a Inlet 31b Outlet 32 Gear 40 Cooler 40a Channel 40b Fin 51 Branch channel 90 Oil channel 151 First channel 152 Second channel 153 Third channel 154 Fourth channel 155 Branch channel section 211 Shaft 212 Rotor body 221 Stator core 222 Coil C Rotating shaft J1 Motor shaft O Oil P Reservoir

Claims (7)

A motor having a rotor that rotates around a motor shaft, and a stator that faces the rotor in a radial direction with a gap therebetween;
a cylindrical housing having a motor chamber that accommodates the motor and a cooling medium that cools the motor;
a refrigerant flow path arranged outside the motor chamber and through which the cooling medium flows;
a pump that circulates the cooling medium;
A cooler that cools the cooling medium,
The housing has a cylindrical peripheral wall portion that extends in the axial direction and circumferentially surrounds the motor chamber,
The refrigerant flow path is formed to extend in the circumferential direction and communicates with an inlet and an outlet opening facing the motor chamber,
The pump is
a pump chamber that communicates the cooling medium suction port and discharge port;
a gear that is housed in the pump chamber and pumps the cooling medium through rotation;
has
The pump and the cooler are provided in the refrigerant flow path and arranged in order in a circumferential direction,
The inflow port opens in the peripheral wall,
The refrigerant flow path has a first flow path that penetrates the peripheral wall portion with the inflow port as one end and directly connects the inflow port and the suction port,
A motor unit, wherein a rotation axis of the gear is arranged to intersect with the motor axis. The motor unit according to claim 1, further comprising a storage section that is arranged between the inlet on the refrigerant flow path and the pump and stores the refrigerant. A plurality of the outflow ports are provided in line in the axial direction,
The motor unit according to claim 1 or 2, wherein the refrigerant flow path has a branch flow path portion that branches into a plurality of flow paths between the outlet and the cooler and communicates with the outlet. The motor unit according to claim 1, wherein the cooling medium is oil. The motor unit according to any one of claims 1 to 4, wherein the outflow port opens in the peripheral wall. The motor unit according to any one of claims 1 to 5, wherein the inlet, the pump, the cooler, and the outlet are arranged in order in a circumferential direction. The motor unit according to claim 2 , wherein the storage section is provided within the pump chamber.

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