JP5331565B2 - Motor unit - Google Patents

Description

  The present invention relates to a motor unit.

2. Description of the Related Art Conventionally, a motor including a stator around which a coil is wound, a rotor disposed inside the stator, and a shaft that is press-fitted and fixed coaxially with the rotor and rotatably supported is known. In the motor, when a current flows through a coil wound around the stator, an attractive or repulsive force is generated between the permanent magnet of the rotor and the stator, so that the rotor rotates.
Here, when the motor is driven, a permanent magnet or a coil wound around the stator generates heat. Therefore, Patent Document 1 proposes an apparatus that cools a coil by supplying oil to a transition part of the coil formed on both axial sides of the stator core.

JP 2006-115650 A

  By the way, in patent document 1 mentioned above, since oil is directly discharged from piping to the transition part of a coil and there is no mechanism which cools oil itself, there exists a limit in cooling efficiency.

  Accordingly, the present invention has been made in view of the above circumstances, and provides a motor unit capable of efficiently cooling a coil using oil.

  In order to solve the above-described problem, the invention described in claim 1 includes an annular yoke portion (for example, the yoke portion 47 in the embodiment), and a teeth portion that protrudes radially inward from the yoke portion ( For example, the cylindrical shape provided with the stator core (for example, stator core 55 in the embodiment) having a tooth portion 48 in the embodiment, and the coil (for example, the coil 20 in the embodiment) wound around the tooth portion. Of the stator (for example, the stator 21 in the embodiment) and a rotor (for example, the rotor 22 in the embodiment) that is opposed to the inside of the stator and that is driven to rotate (for example, the motor 23 in the embodiment) ), A housing that can accommodate the motor (for example, the motor housing 11 in the embodiment), and the stay A water jacket (for example, the water jacket 15 in the embodiment) disposed along the peripheral surface of the housing, and a first oil passage formed along the axial direction on the radially outer side of the water jacket in the wall portion of the housing ( For example, the oil passage 73 in the embodiment and the first transition portion (for example, implementation) of the coil formed along the axial direction on the radially inner side of the water jacket and projecting from one axial end side of the stator core. A second oil passage (e.g., oil passage 77 in the embodiment) configured to be able to supply oil (e.g., cooling oil 71 in the embodiment) to the first transition portion 51r) in the embodiment, the first oil passage, and the A second transition portion of the coil (for example, in the embodiment) provided between the second oil passage and projecting to the other end side in the axial direction of the second oil passage or the stator core. An oil distribution path (for example, oil distribution member 75 in the embodiment) configured to be able to distribute the oil to the second transition portion 51l) and an oil pump (for example, oil pump 72 in the embodiment) that circulates the oil. And an oil circulation mechanism (for example, the oil cooling mechanism 70 in the embodiment).

According to a second aspect of the present invention, a cutout portion (for example, the cutout portion 57 in the embodiment) is formed along the axial direction on the outer peripheral surface of the stator core (for example, the outer peripheral surface 55a in the embodiment), and the second oil The path is formed by the notched portion and the inner peripheral surface of the water housing (for example, the inner peripheral surface 11a in the embodiment) by press-fitting and fixing the stator to the housing .

  According to a third aspect of the present invention, in the three-phase AC motor in which the coil is distributedly wound around the tooth portion, the notch portions are radially outward of the teeth portion positioned on both sides of the wound coil. It is characterized by being formed at a position.

  According to the first aspect of the present invention, the cooled oil after flowing in the vicinity of the water jacket is supplied to the first and second transition portions of the coils formed on both axial sides of the stator core. be able to. Therefore, the coil can be effectively cooled. Further, when the oil flows through the second oil passage, the stator core can also absorb heat and the stator core can be cooled.

  According to the second aspect of the present invention, the second oil passage is formed by forming the notch portion on the outer peripheral surface of the stator core and press-fitting and fixing the stator core to the housing. Can be formed. Further, since it is not necessary to provide a space for the second oil passage between the housing and the stator, it is possible to suppress an increase in size of the motor unit.

  According to the third aspect of the present invention, since the notches are formed on the outer peripheral surface of the stator core at substantially equal intervals along the circumferential direction, the magnetic characteristics are hardly affected. Moreover, since oil can be supplied equally to the transition part of the coil, the coil can be cooled more effectively.

It is a schematic longitudinal cross-sectional view of the vehicle motor unit in the embodiment of the present invention. It is a front view of the rotor in the embodiment of the present invention. It is the perspective view which extracted the shaft and motor part of the motor unit for vehicles in the embodiment of the present invention. It is the A section enlarged view of FIG. It is a perspective view of the oil distribution member in the embodiment of the present invention.

Next, an embodiment of the present invention will be described with reference to FIGS. In the present embodiment, description will be made using a motor unit for driving the vehicle.
FIG. 1 is a schematic sectional view of a vehicle motor unit. As shown in FIG. 1, a vehicle motor unit (hereinafter referred to as a motor unit) 10 is fastened to a motor housing 11 that houses a motor 23 having a stator 21 and a rotor 22, and one side of the motor housing 11. A transmission housing 12 that houses a power transmission portion (not shown) that transmits power from the shaft 24 of the motor 23, a sensor housing 13 that is fastened to the other side of the motor housing 11 and houses the rotation sensor 25 of the motor 23; It has.

  The motor housing 11 is configured as a motor chamber 36, the mission housing 12 is configured as a mission chamber 37, and the sensor housing 13 is configured as a sensor chamber 38.

  The motor housing 11 is formed in a substantially cylindrical shape so as to cover the entire motor 23. A bearing 26 that rotatably supports one end of the shaft 24 of the motor 23 is provided at the boundary between the motor housing 11 and the transmission housing 12, and the motor 23 has a bearing 26 at the boundary between the motor housing 11 and the sensor housing 13. A bearing 27 that rotatably supports the other end of the shaft 24 is provided. A permanent magnet 30 is attached to the outer peripheral edge of the rotor 22 connected to the shaft 24. The motor unit 10 is arranged so that the axial direction of the shaft 24 faces the left and right direction of the vehicle.

  FIG. 2 is a front view of the rotor as seen from the axial direction. As shown in FIG. 2, the rotor 22 includes a substantially cylindrical rotor core 41 on which magnetic plate materials 33 are stacked. The shaft 24 is fixed to the through hole 42 formed in the central portion in the radial direction of the rotor core 41. In the vicinity of the radially outer end of the rotor core 41, a plurality of housing holes 43 that penetrate the rotor core 41 in the axial direction are formed. Inside each housing hole 43, a permanent magnet 30 made of a rare earth such as neodymium is formed. Contained. That is, the motor 23 of the present embodiment is a so-called IPM (Interior Permanent Magnet) motor in which the permanent magnet 30 is embedded in the rotor core 41. The permanent magnet 30 is magnetized in the radial direction of the rotor core 41. In addition, a plurality of permanent magnets 30 are arranged at substantially equal intervals along the circumferential direction of the rotor core 41 (eight in this embodiment), and the permanent magnets 30 adjacent in the circumferential direction are alternately magnetized in the opposite direction. . Further, the rotor core 41 is formed with a plurality of lightening holes 45 in order to reduce the weight. A plurality (eight in this embodiment) of the lightening holes 45 are formed between the through holes 42 and the accommodation holes 43 at substantially equal intervals in the circumferential direction. Note that F is the rotational direction of the rotor 22 when the vehicle is moving forward.

  FIG. 3 is a perspective view showing only the motor 23 and the shaft 24 of the motor unit 10. As shown in FIG. 3, the rotor 22 is rotatably attached to the shaft 24, and the stator 21 is disposed opposite to the circumferential surface of the rotor 22. The stator 21 is formed in a cylindrical shape having a substantially circular outer shape when viewed from the axial direction, and a yoke portion 47 constituting an outer peripheral portion, and a plurality extending from the yoke portion 47 toward the inner diameter direction (rotor 22 direction). The stator core 55 is provided. A plurality of tooth portions 48 of the stator core 55 are formed at equal intervals in the circumferential direction, and the coil 20 is wound around a slot 49 formed between the adjacent tooth portions 48, 48. In the present embodiment, the coil 20 is wound with distributed winding, and the coils 20U, 20V, and 20W are wound around predetermined slots 49, respectively. Accordingly, the coils 20U, 20V, and 20W are formed with crossover portions 51 (51U, 51V, and 51W) that protrude outward from both axial end surfaces of the stator core 55. In addition, the transition part 51 is formed in the axial direction both end surface of the stator core 55, the transition part on the vehicle right side is set as the 1st transition part 51r, and the transition part on the vehicle left side is set as the 2nd transition part 51l (refer FIG. 1). ).

  Further, as shown in FIG. 3, end face plates 60 and 60 are arranged so as to abut on both end faces 41 a and 41 b of the rotor core 41. The end face plate 60 is a ring-shaped member having an outer diameter equivalent to the outer diameter of the rotor core 41, is press-fitted and fixed to the shaft 24, and closes at least a part of the accommodation hole 43 at the peripheral edge portion thereof. By closing the accommodation hole 43 in this way, the permanent magnet 30 is prevented from jumping out of the accommodation hole 43. The end face plate 60 is made of, for example, a stainless steel plate material having a high thermal conductivity. By using the end plate 60 having high thermal conductivity, the heat generated in the permanent magnet 30 can be efficiently absorbed, and the temperature rise of the permanent magnet 30 can be effectively suppressed.

  Here, as shown in FIG. 3, a plurality of notches 57 are formed on the outer peripheral surface 55 a of the stator core 55 along the axial direction. The notches 57 are formed at substantially equal intervals in the circumferential direction, and are formed at positions radially outside the teeth 48 that are located on both sides of the wound coil 20. Specifically, for example, there are a plurality of (not shown) notch portions 57 at positions radially outside the teeth portion 48 located on the outer side in the circumferential direction of the two slots 49 over which the U-phase coil 20U of the three phases is stretched. In the embodiment, 8 places) are formed. The stator 21 is press-fitted and fixed to the inner peripheral surface 11 a of the motor housing 11. The motor housing 11 is provided with a water jacket 15. The water jacket 15 is provided at a position corresponding to the outer peripheral surface 55 a of the stator core 55 so that the stator 21 can be cooled. The water jacket 15 is provided with a length substantially the same as the axial length of the stator core 55.

  Returning to FIG. 1, an oil cooling mechanism 70 for cooling the bearings 26 and 27, the motor 23, and the like is provided inside the motor unit 10. The oil cooling mechanism 70 includes a cooling oil 71, an oil pump 72 that circulates the cooling oil 71, and an oil passage 73 through which the cooling oil 71 flows. The cooling oil 71 is stored in the lower part of the motor chamber 36, and the cooling oil 71 is pumped up by an oil pump 72 provided in the mission chamber 37, and circulates in the motor unit 10 through the oil path 73. ing.

Next, a method for cooling the motor 23 using the oil cooling mechanism 70 will be described.
As shown in FIG. 4, an oil passage 73 is formed along the axial direction on the radially outer side of the water jacket 15 in the motor housing 11. An oil distribution member 75 is provided in the oil passage 73 near the boundary between the motor housing 11 and the sensor housing 13. The cooling oil 71 is guided to the oil distribution member 75 or the oil passage 73 of the sensor housing 13. The cooling oil 71 guided to the oil distribution member 75 is an oil passage formed by the second transition part 51l of the coil 20 or the notch part 57 of the stator core 55 and the inner peripheral surface 11a of the motor housing 11 formed on the left side of the vehicle. 77 to be guided to any one of 77.

  Here, the cooling oil 71 guided to the oil passage 77 formed by the notch portion 57 of the stator core 55 and the inner peripheral surface 11a of the motor housing 11 passes through the oil passage 77 and is then formed on the right side of the vehicle. It is configured to be supplied to 20 first crossover parts 51r.

  As shown in FIG. 5, the oil distribution member 75 is a ring-shaped member when viewed from the axial direction. The oil distribution member 75 is press-fitted and fixed to, for example, the inner peripheral surface 11b (see FIG. 4) of the motor housing 11 where the water jacket 15 is not provided. An introduction hole 81 into which the cooling oil 71 can be introduced from the oil passage 73 is formed at the top of the oil distribution member 75. The inside of the oil distribution member 75 is hollow, and the cooling oil 71 can flow therethrough. A first oil supply hole 83 for supplying the cooling oil 71 to the oil passage 77 is formed on the side surface 75a of the oil distribution member 75 on the side where the stator core 55 is disposed. Further, a second oil supply hole 85 for supplying the cooling oil 71 to the second transition portion 51l of the coil 20 on the left side of the vehicle is formed on the inner peripheral surface 75b of the oil distribution member 75. A plurality of the first oil supply holes 83 and the second oil supply holes 85 are formed at substantially equal intervals in the circumferential direction, and are respectively formed corresponding to the positions where the notches 57 of the stator core 55 are formed. That is, the first oil supply hole 83 and the oil passage 77 communicate with each other.

  The driving time of the motor unit 10 configured as described above will be described. When the motor unit 10 is driven, the rotor 22 and the shaft 24 rotate. When the motor unit 10 is driven, various parts such as the coil 20 and the stator 21 generate heat. The cooling oil 71 is circulated by the oil cooling mechanism 70 for the purpose of cooling the portions that have generated heat in this way and ensuring the lubrication performance of the bearings 26 and 27. The cooling oil 71 circulated by the oil pump 72 is supplied to various places while passing through the oil passage 73.

  Here, the cooling oil 71 passing through the oil passage 73 of the motor housing 11 can be heat-exchanged by the water jacket 15 provided on the radially inner side of the oil passage 73 to cool the cooling oil 71. A part of the cooling oil 71 guided by the oil distribution member 75 is supplied from the oil distribution unit 75 to the second transition portion 51l of the coil 20 formed on the left side of the vehicle, thereby cooling the coil 20.

Further, another part of the cooling oil 71 is guided from the oil distributor 75 to the oil passage 77. The cooling oil 71 passing through the oil passage 77 from the left side to the right side of the vehicle is heat-exchanged by the water jacket 15 provided on the radially outer side of the oil passage 77 and further cooled. The cooling oil 71 guided to the right side of the vehicle is supplied to the first transition portion 51r of the coil 20 formed on the right side of the vehicle to cool the coil 20.
In the oil distribution member 75, the remaining cooling oil that has not been guided to the coil 20 is guided to the sensor housing 13 side and supplied to the bearing 27 and the rotation sensor 25.

  According to this embodiment, the cooled cooling oil 71 after flowing through the vicinity of the water jacket 15 to the first transition portion 51r and the second transition portion 51l of the coil 20 formed on both axial sides of the stator core 55. Can be supplied. Therefore, the coil 20 can be effectively cooled. Further, when oil flows through the oil passage 77, the heat of the stator core 55 is absorbed and the stator core 55 can be cooled at the same time.

  Further, the notch 57 is formed in the outer peripheral surface 55a of the stator core 55, and the oil path 77 is formed by press-fitting and fixing the stator core 55 to the motor housing 11. Therefore, the oil path 77 can be formed with a simple configuration. it can. In addition, since it is not necessary to provide a space for the oil passage 77 between the motor housing 11 and the stator 21, an increase in size of the motor unit 10 can be suppressed.

  Furthermore, since the notches 57 are formed on the outer peripheral surface 55a of the stator core 55 at substantially equal intervals along the circumferential direction, the magnetic characteristics are hardly affected. Moreover, since the cooling oil 71 can be supplied equally to the transition part 51 of the coil 20, the coil 20 can be cooled more effectively.

The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention. That is, the specific structure and shape described in the embodiment are merely examples, and can be changed as appropriate.
For example, in the present embodiment, the oil distribution member 75 is separate from the motor housing 11 and is press-fitted and fixed. However, the oil distribution member 75 and the motor housing 11 may be integrally formed.

  Further, in the present embodiment, the case where the oil distribution member 75 is formed in a ring shape has been described, but the cooling oil is not supplied to the coil immersed in the cooling oil, for example, only the upper half when viewed from the axial direction. Alternatively, the cooling oil may be supplied only to the coil portion above the shaft.

  Further, in the present embodiment, the outer peripheral surface 55a of the stator core 55 is disposed on the outer side in the radial direction of the tooth portion 48 positioned on the outer side in the circumferential direction of the two slots 49 over which the U-phase coil 20U of the three phases is stretched. Although the cutout portion 57 is formed at the position, the cutout portion 57 may be formed at a position corresponding to each of the V phase and the W phase other than the U phase. By doing in this way, the influence on a magnetic characteristic can be reduced further.

  DESCRIPTION OF SYMBOLS 10 ... Motor unit 11 ... Motor housing 11a ... Inner peripheral surface 15 ... Water jacket 20 ... Coil 21 ... Stator 22 ... Rotor 23 ... Motor 47 ... Yoke part 48 ... Teeth part 51l ... 2nd transition part 51r ... 1st transition part 55 ... Stator core 55a ... Outer peripheral surface 57 ... Notch part 70 ... Oil cooling mechanism (oil circulation mechanism) 71 ... Cooling oil (oil) 72 ... Oil pump 73 ... Oil path (first oil path) 75 ... Oil distribution member (oil distribution path) 77 ... Oil passage (second oil passage)

Claims (3)

A cylindrical stator provided with a stator core having an annular yoke portion, and a tooth portion that protrudes radially inward from the yoke portion, and a coil wound around the tooth portion, and the stator A rotor configured to be opposed to and driven to rotate inside the motor,
A housing capable of accommodating the motor;
A water jacket arranged along the circumferential surface of the stator;
A first oil passage formed along the axial direction on the radially outer side of the water jacket in the wall portion of the housing, and an axial end of the stator core formed along the axial direction on the radially inner side of the water jacket. Provided between the first oil passage and the second oil passage, the second oil passage configured to be able to supply oil to the first transition portion of the coil that protrudes to the side, and the second oil passage. An oil comprising an oil distribution path configured to be able to distribute the oil to a second transition portion of the coil formed to project to the other end side in the axial direction of the path or the stator core, and an oil pump for circulating the oil And a circulation mechanism. A notch is formed along the axial direction on the outer peripheral surface of the stator core,
2. The motor unit according to claim 1, wherein the second oil passage is formed by the notched portion and an inner peripheral surface of the water housing by press-fitting and fixing the stator to the housing . In the three-phase AC motor in which the coil is distributedly wound around the teeth portion,
3. The motor unit according to claim 2, wherein the notch portion is formed at a radially outer position of the tooth portion located on both sides of the wound coil.

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