JP2005086894A - In-wheel motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-wheel motor which can uniformly cool a stator coil. <P>SOLUTION: The stator coil 62 comprises U-phase coils U1 to U7, V-phase coils V1 to V7 and W-phase coils W1 to W7. The U-phase coil U1, the V-phase coil v1 and the W-phase coil W1 are wound on teeth 611 to 613, respectively. Other U-phase coils U2 to U7, V-phase coils V2 to V7 and W-phase coils W2 to W7 are wound similar to the U-phase coil U1, the V-phase coil V1 and the W-phase coil W1. Oil level is kept at a position, where the U-phase coil U1, the V-phase coil V1 and the W-phase coil W1 are soaked at the same time in oil. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an in-wheel motor, and more particularly to an in-wheel motor capable of efficiently cooling the motor.

  Patent Document 1 discloses an in-wheel motor in which a drive unit is housed in a wheel rim. The drive unit includes a case, a motor, and a planetary gear unit. The case houses the motor and the planetary gear unit. An oil reservoir chamber is provided in the lower part of the motor and the case, and oil (lubricating oil) is stored in the oil reservoir chamber.

  The motor rotor includes a rotor laminate and a hub. The hub supports the rotor laminate. The hub has an outer peripheral side flange that extends in the direction of the rotation axis of the rotor. This outer peripheral side collar part is located in the rotating shaft side rather than the outer peripheral surface of a rotor.

  The amount of oil varies between a position where the outer peripheral surface of the rotor is slightly immersed and a position where the outer peripheral side flange of the hub is immersed. That is, a part of the stator and a part of the rotor are immersed in oil.

  When the rotor rotates, the rotor laminate and the outer flange side scoop up the oil. Then, the scooped-up oil travels along the rib provided in the case, lubricates the bearing and the planetary gear unit, and returns to the oil reservoir chamber.

Thus, in the conventional in-wheel motor, a part of the stator and a part of the rotor are immersed in oil that lubricates gears and the like in the in-wheel motor.
JP 2001-32914 A

  However, in the conventional in-wheel motor, there is a problem that the stator coil of each phase is not immersed in oil, and cooling of the stator coil becomes uneven. For example, when the in-wheel motor includes a three-phase motor composed of a U-phase, a V-phase, and a W-phase, a part of the U-phase coil and a part of the V-phase coil are immersed in oil, but a part of the W-phase coil Is not immersed in oil and the W-phase coil cannot be cooled by oil. As a result, the cooling of the stator coil can be non-uniform.

  Accordingly, the present invention has been made to solve such a problem, and an object thereof is to provide an in-wheel motor capable of uniformly cooling a stator coil.

  According to this invention, an in-wheel motor is an in-wheel motor comprised by a multiphase motor. The multiphase motor includes a plurality of phase coils corresponding to the number of phases. At least a part of each of the plurality of phase coils is immersed in the lubricating oil in the multiphase motor.

  Preferably, the lubricating oil is an oil that lubricates a gear mechanism in the in-wheel motor and cools the multiphase motor.

  Preferably, the oil level of the lubricating oil is maintained below the lowermost rotor surface of the multiphase motor.

  In the in-wheel motor according to the present invention, among the plurality of phase coils of the multiphase motor, at least a part of each phase coil is immersed in oil. And when a part of each phase coil is cooled by oil, the heat generated in the part not immersed in the oil of each phase coil is conducted to the part immersed in the oil by thermal conduction, to the lubricating oil Released.

  Therefore, according to the present invention, the stator coil can be uniformly cooled.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a schematic sectional view of an electric wheel provided with an in-wheel motor according to an embodiment of the present invention. Referring to FIG. 1, an electric wheel 100 includes a wheel disc 10, a wheel hub 20, cases 30 and 31, a brake rotor 40, a brake caliper 50, a motor 60, bearings 73 to 76, and a planetary gear 80. An oil pump 90, a shaft 110, an oil reservoir 120, an oil passage 140, and a tire 150.

  The electric wheel 100 is suspended from the frame of the automobile body by an upper arm and a lower arm (not shown).

  The wheel disc 10 has a substantially cup shape and includes a low portion 10A and a cylindrical portion 10B. The wheel disc 10 includes a wheel hub 20, cases 30 and 31, a brake rotor 40, a brake caliper 50, a motor 60, bearings 73 to 76, a planetary gear 80, an oil pump 90, a shaft 110, an oil reservoir 120, and an oil passage 140. Store. The wheel disc 10 is connected to the wheel hub 20 by fastening the lower portion 10 </ b> A to the wheel hub 20 with screws 1 and 2. The wheel hub 20 is spline fitted to the shaft 110. The wheel hub 20 that is spline-fitted to the shaft 110 is rotatably supported by a bearing 76 and smoothly rotates by grease lubrication 71 and 72.

  The brake rotor 40 is arranged such that an inner peripheral end is fixed to the wheel hub 20 by screws 3 and 4 and an outer peripheral end passes through the brake caliper 50. The brake caliper 50 includes a brake piston 51 and brake pads 52 and 53. The brake pads 52 and 53 sandwich the outer peripheral end of the brake rotor 40.

  When brake oil is supplied from the opening 50A, the brake piston 51 moves to the right side of the page and pushes the brake pad 52 to the right side of the page. When the brake pad 52 is moved to the right side of the drawing by the brake piston 51, the brake pad 53 is moved to the left side of the drawing in response. As a result, the brake pads 52 and 53 sandwich the outer peripheral end of the brake rotor 40 and the electric wheel 100 is braked.

  Cases 30 and 31 are arranged on the left side of the wheel hub 20 in the drawing. The case 30 is connected to the case 31 by the screw 5. Cases 30 and 31 house the motor 60.

  Motor 60 includes a stator core 61, a stator coil 62, and a rotor 63. The stator core 61 is fixed to the case 31. The stator coil 62 is wound around the stator core 61. Stator coil 62 includes a U-phase coil, a V-phase coil, and a W-phase coil. Therefore, the motor 60 is a three-phase motor.

  The rotor 63 is disposed on the inner peripheral side of the stator core 61 and the stator coil 62.

  Planetary gear 80 includes a sun gear shaft 81, a sun gear portion 82, a pinion gear 83, a planetary carrier 84, and a ring gear 85. Sun gear shaft 81 is connected to rotor 63 of motor 60. The sun gear shaft 81 is rotatably supported by bearings 73 and 74. Sun gear portion 82 is connected to sun gear shaft 81.

  The pinion gear 83 meshes with the sun gear portion 82 and is rotatably supported by bearings 75 and 76. Planetary carrier 84 is connected to pinion gear 83 and is splined to shaft 110. The ring gear 85 is fixed to the case.

  The oil pump 90 is provided at one end of the shaft 110. As described above, the shaft 110 is spline-fitted with the wheel hub 20 and the planetary carrier 84, so that the shaft 110 is rotatably supported by the bearing 76 and smoothly rotates by the grease lubrication 71 and 72. The shaft 110 incorporates an oil passage 111 and an oil hole 112.

  The oil passage 121 is provided in the needle bearing portion of the pinion gear 83 of the planetary gear 80. The oil reservoir 120 is provided in the lower part of the motor 60 and accumulates the oil 130. The oil passage 140 has one end connected to the oil pump 90 and the other end inserted into the oil reservoir 120.

  The oil pump 90 pumps up the oil accumulated in the oil reservoir 120 through the oil passage 140, and supplies the pumped oil to the oil passage 111.

  The tire 150 is fixed to the outer edge of the cylindrical portion 10 </ b> B of the wheel disc 10.

  FIG. 2 is a plan view of the stator core 61, the stator coil 62, and the rotor 63 shown in FIG. 1 as viewed from the wheel disk 10 side. Referring to FIG. 2, stator coil 62 includes U-phase coils U1 to U7, V-phase coils V1 to V7, and W-phase coils W1 to W7. Each of U-phase coils U1-U7, V-phase coils V1-V7 and W-phase coils W1-W7 is made of copper. U-phase coils U1-U7 are connected in series. V-phase coils V1 to V7 are also connected in series, and W-phase coils W1 to W7 are also connected in series.

  U phase coil U1, V phase coil V1 and W phase coil W1; U phase coil U2, V phase coil V2 and W phase coil W2; U phase coil U3, V phase coil V3 and W phase coil W3; U phase coil U4; V phase coil V4 and W phase coil W4; U phase coil U5, V phase coil V5 and W phase coil W5; U phase coil U6, V phase coil V6 and W phase coil W6; and U phase coil U7, V phase coil V7 And W phase coil W7 comprises three phase coil UVW1, UVW2, UVW3, UVW4, UVW5, UVW6, UVW7, respectively.

  Stator core 61 has teeth 611 to 612 arranged continuously. Then, U-phase coil U1, V-phase coil V1 and W-phase coil W1 of three-phase coil UVW1 are wound around teeth 611, 612 and 613, respectively. Thus, the three-phase coil UVW1 includes the U-phase coil U1, the V-phase coil V1, and the W-phase coil W1 wound around the stator core 61 so as to be continuously arranged.

  Similarly, the three-phase coil UVW2 includes a U-phase coil U2, a V-phase coil V2, and a W-phase coil W2 wound around the stator core 61 so as to be continuously arranged. The three-phase coil UVW3 is continuous. The U-phase coil U3, the V-phase coil V3, and the W-phase coil W3 are wound around the stator core 61 so as to be disposed in a row. The three-phase coil UVW4 is wound around the stator core 61 so as to be disposed continuously. The U-phase coil U4, the V-phase coil V4, and the W-phase coil W4, and the three-phase coil UVW5 is wound around the stator core 61 so as to be continuously arranged. The three-phase coil UVW6 includes a U-phase coil U6, a V-phase coil V6, and a W-phase coil that are wound around the stator core 61 so as to be continuously arranged. Consists W6, 3-phase coils UVW7 consists U-phase coil U7, V-phase coil V7 and W-phase coils W7 which is wound stator core 61 wound so as to be arranged in succession.

  An air gap GAP is formed between the inner peripheral surface 62 </ b> A of the stator core 62 and the outer peripheral surface 63 </ b> A of the rotor 63. When the lowest position of the air gap GAP is the position PS1, the level of the oil 130 is set between the position PS1 and the position PS2. Position PS2 is the lowest oil level at which one coil of U-phase coils U1-U7, one coil of V-phase coils V1-V7, and one coil of W-phase coils W1-W7 are immersed in oil 130 at the same time. Position.

  In this case, each of the U-phase coils U1 to U7, the V-phase coils V1 to V7, and the W-phase coils W1 to W7 does not need to be entirely immersed in the oil 130, and a part thereof is immersed in the oil 130. It only has to be done.

  FIG. 2 shows a position PS2 when a part of the U-phase coil U1, a part of the V-phase coil V1, and a part of the W-phase coil W1 are immersed in the oil 130 at the same time. If a part of the U-phase coil U1 is immersed in the oil 130, the U-phase coils U1 to U7 are made of copper having a high thermal conductivity and are connected in series. The heat generated in the U-phase coils U2 to U7 that are not present is conducted to the U-phase coil U1 and released to the oil 130. Then, the entire U-phase coils U <b> 1 to U <b> 7 are cooled by the oil 130.

  If part of the V-phase coil V1 and part of the W-phase coil W1 are immersed in the oil 130, the V-phase coils V1 to V7 and the entire W-phase coils W1 to W7 are similarly cooled by the oil 130. The

  As a result, U-phase coils U1-U7, V-phase coils V1-V7 and W-phase coils W1-W7 can be cooled uniformly. That is, the stator coil 62 can be uniformly cooled.

  Therefore, in the present invention, at least a part of U-phase coil U1, a part of V-phase coil V1, and a part of W-phase coil W1 need only be immersed in oil 130 at the same time.

  Note that the oil level is set to the position PS1 or lower when the oil level is set in the air gap GAP, and the rotor 63 is immersed in the oil 130 due to the fluctuation of the oil level. If it does so, the viscous resistance of rotation of the rotor 63 will become large. Therefore, the oil level is set to the lowermost position (PS1) of the air gap GAP.

  Positions PS1 and PS2 are determined according to the diameter of stator core 61, the number of coils constituting each of the U-phase coil, V-phase coil and W-phase coil, the width of one coil of each phase coil, and the like. .

  Referring to FIG. 1 again, when an alternating current is supplied to stator coil 62 by a switching circuit (not shown) provided in the main body of the automobile on which motor-driven wheel 100 is mounted, rotor 63 rotates and motor 60 is rotated. Outputs a predetermined torque. The output torque of the motor 60 is transmitted to the planetary gear 80 through the sun gear shaft 81. The planetary gear 80 changes the output torque received from the sun gear shaft 81 by the sun gear portion 82 and the pinion gear 83, that is, shifts and outputs it to the planetary carrier 84. The planetary carrier 84 transmits the output torque of the planetary gear 80 to the shaft 110, and the shaft 110 rotates the wheel hub 20 and the wheel disc 10 at a predetermined rotational speed. Thereby, the electric wheel 100 rotates at a predetermined number of rotations.

  On the other hand, the oil pump 90 pumps up the oil 130 from the oil reservoir 120 via the oil passage 140, and supplies the pumped oil 130 to the oil passage 111 provided inside the shaft 110.

  Then, the oil supplied to the oil passage 111 is discharged from the oil hole 112 by the centrifugal force generated by the rotation of the shaft 110 while moving in the oil passage 111. The oil passage 121 supplies the oil discharged from the shaft 110 to the planetary gear 80 and lubricates the planetary gear 80. Further, the oil discharged from the shaft 110 is supplied to the stator coil 62 and the bearings 73 to 76 to cool the stator core 62 and lubricate the bearings 73 to 76. The oil supplied to the stator coil 62 and the bearings 73 to 76 is stored in the oil reservoir 120 by gravity drop. In addition, one coil of U-phase coils U1 to U7, one coil of V-phase coils V1 to V7 and one coil of W-phase coils W1 to W7 are immersed in oil 130 stored in oil reservoir 120. Stator coil 62 (U-phase coils U1-U7, V-phase coils V1-V7 and W-phase coils W1-W7) is uniformly cooled by the above-described mechanism.

  In the above description, the case of a three-phase motor has been described. However, the present invention is generally applicable to a multi-phase motor. Therefore, the in-wheel motor by this invention is an in-wheel motor comprised by a multiphase motor. In this case, the multiphase motor includes a plurality of phase coils corresponding to the number of phases, and at least a part of each of the plurality of phase coils is immersed in oil.

  In addition, the wheel disc 10, the wheel hub 20, the cases 30, 31, the motor 60, the bearings 73 to 76, the planetary gear 80, the oil pump 90, the shaft 110, the oil reservoir 120, and the oil passage 140 are formed in accordance with the present invention. Is configured.

  Further, as described above, the oil 130 stored in the oil reservoir 120 lubricates the bearings 73 to 76 and the planetary gear 80, and cools the stator coil 62, so that the oil 130 is a gear mechanism (planetary gear) in the in-wheel motor. 80) oil that serves as both lubrication and cooling of the motor 60.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention is applied to an in-wheel motor with good cooling efficiency.

It is a schematic sectional drawing of the electric wheel provided with the in-wheel motor by embodiment of this invention. It is the top view seen from the wheel disk side of the stator core shown in FIG. 1, a stator coil, and a rotor.

Explanation of symbols

  1-5 screw, 10 wheel disc, 10A low part, 10B cylindrical part, 20 wheel hub, 30, 31 case, 40 brake rotor, 50 brake caliper, 50A opening, 51 brake piston, 52, 53 brake pad, 60 Motor, 61 stator core, 62 stator coil, 62A inner peripheral surface, 63A outer peripheral surface, 63 rotor, 71, 72 grease lubrication, 73-76 bearing, 80 planetary gear, 81 sun gear shaft, 82 sun gear portion, 83 pinion gear, 84 planetary carrier, 85 ring gear, 90 oil pump, 100 electric wheel, 110 shaft, 111, 121, 140 oil passage, 112 oil hole, 120 oil reservoir, 130 oil, 150 tire, 611-613 teeth.

Claims (3)

An in-wheel motor composed of a multiphase motor,
The multi-phase motor includes a plurality of phase coils corresponding to the number of phases,
An in-wheel motor in which at least a part of each of the plurality of phase coils is immersed in lubricating oil in the multiphase motor.   The in-wheel motor according to claim 1, wherein the lubricating oil is an oil that lubricates a gear mechanism in the in-wheel motor and cools the multiphase motor.   The in-wheel motor according to claim 1, wherein an oil level of the lubricating oil is maintained below a lowermost rotor surface of the multiphase motor.

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