JP2014009676A - Motor-driven oil pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor-driven oil pump device in which an electric motor and a controller are integrally formed, a water-proof property of the controller can be secured even when a housing of the electric motor is made of metal, and the electric motor can be easily assembled.SOLUTION: A connector shell 20 is molded integrally with a resin cover 15, and a fitting portion 25 axially extended from an inner end face of the cover 15 is fitted to a holding portion 16 extended to a cylindrical portion of a pump housing 13. A rubber annular seal member 27 is fitted to a seal groove 26 formed on the fitting portion 25 of the cover 15 annularly in the circumferential direction, and kept into contact with the holding portion 16 of the pump housing 13 to seal between the pump housing 13 and the cover 15. A fixing portion 28 axially projecting from the inner end face of the cover 15 is brought into contact with a rear side of an insulator 21, and both are joined by vibration welding.

Description

  The present invention relates to an electric oil pump device.

  Conventionally, there is an electric oil pump device that combines an oil pump that circulates fluid (oil) and an electric motor that drives the oil pump. In addition, an electric oil pump device has been proposed that has an electric motor and an oil pump that share a rotating shaft and is arranged side by side in the direction of the central axis of the oil pump. (For example, refer to Patent Document 1). According to the technique of Patent Document 1, a resin motor housing is connected to a pump body constituting an oil pump, and an electric motor and a controller are built in a sealed motor chamber formed in the motor housing. The controller board is accommodated in a space formed on the end surface of the motor housing opposite to the oil pump and covered with a cover so that the controller is integrated with the oil pump and the electric motor.

JP 2004-353536 A

  In such a conventional electric pump unit, for example, a connector for connecting an external power source is formed integrally with the motor housing to reduce the assembly man-hour, and the controller is formed by welding the resin cover and the motor housing. Waterproofness is ensured. Here, when the output of the electric motor is increased, the stator temperature rises due to heat generation of the stator coil of the electric motor. For this reason, it is necessary to suppress the temperature rise of the motor, and the heat dissipation of the motor may be improved by using a metal motor housing such as aluminum. However, if the motor housing is made of metal, the motor housing and the resin connector cannot be integrally formed. Therefore, it is necessary to attach a grommet or packing to the motor housing, and then screw the connector to attach the connector. As a result, the structure of the electric motor becomes complicated and the assemblability may deteriorate.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to form an electric motor and a controller integrally, and to ensure waterproofness of the controller even in a metal motor housing. An object of the present invention is to provide an electric oil pump device that can easily assemble a motor.

  In order to solve the above-described problem, an electric oil pump device according to claim 1 is provided with an oil pump, an electric motor sharing a rotating shaft with the oil pump, and adjacent to the electric motor, and driving the electric motor. A controller for controlling, a rotor provided on the rotating shaft of the electric motor, an insulator mounted on a stator core, and a plurality of stator subassies having coils wound around the insulator are fixed in an annular shape and A stator fixed to the outside of the outer peripheral surface of the rotor, a bus bar fixed to the insulator by integral molding, and connected to the coil, and a cylindrical outer peripheral portion extending in the axial direction opposite to the oil pump. A metal pump housing having a holding portion and having the stator fixed inside; and the oil pump of the pump housing. A control board of the controller housed in a control chamber formed on the opposite end of the controller, a resin lid formed integrally with the connector and covering the open end of the control chamber, and provided on the lid An annular seal member which is mounted in a circumferential annular seal groove and seals between the pump housing, and a cylindrical outer peripheral portion of the lid extends in the axial direction toward the oil pump side, and the bus bar. And a fitting portion that fits with a holding portion of the pump housing, and a fixing portion that protrudes axially from the inside of the lid toward the oil pump side. The gist.

  According to the above configuration, the electric oil pump device according to the present invention is a resin-made resin that is integrally formed with the connector, sharing the holding portion extending the cylindrical outer peripheral end portion of the metal pump housing with the housing of the electric motor. Since the fitting portion is fitted to the fitting portion of the lid, the contact between the bus bar molded in the insulator and the pump housing can be prevented. Further, since an annular seal member is mounted in a circumferential annular seal groove provided on the lid and the lid is fitted with the pump housing, the control housed in the control chamber at the end of the electric motor side of the pump housing The waterproofness of the substrate can be secured. Thereby, while being able to assemble an electric motor easily in a pump housing, the heat dissipation of an electric motor can be improved.

  An electric oil pump device according to a second aspect is the electric oil pump device according to the first aspect, wherein the fixing portion is welded and fixed to a rear side of the insulator. According to the above configuration, in the electric oil pump device according to the present invention, the fixing portion protruding in the axial direction from the inside of the resin lid is fixed to the insulator rear side of the stator of the electric motor by welding. While securing to the metal housing of an electric motor reliably, the waterproofness of the control board in the control chamber of an electric motor is securable.

  According to the present invention, there is provided an electric oil pump device in which the electric motor and the controller are integrally formed, the waterproofness of the controller is ensured even when the electric motor housing is made of metal, and the electric motor can be easily assembled. it can.

1 is a longitudinal sectional view showing a schematic configuration of an electric oil pump device according to an embodiment of the present invention. The longitudinal cross-sectional view which expanded the housing principal part of the electric motor of FIG.

Next, an example of an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of an electric oil pump device 1 according to an embodiment of the present invention, and FIG. 2 is an enlarged longitudinal sectional view of a main part of a housing of the electric motor of FIG. As shown in FIG. 1, an electric oil pump device 1 is used as a hydraulic pump for an automobile transmission, and an oil pump (for example, an internal gear pump) 2 and an electric motor 3 that rotationally drives the oil pump 2 are disposed in a housing. It is integrated. A control board (hereinafter referred to as a board) 24 of the controller 4 is also incorporated in the housing. An electric motor (hereinafter referred to as a brushless motor) 3 shown in FIG. 1 is a brushless sensorless motor having a three-phase winding. The electric oil pump device 1 is fastened and fixed to a transmission or an engine case (not shown) via a plurality of flanges protruding from the end face of the pump plate 14 with bolts arranged in the circumferential direction with respect to the axis center through an attachment hole. Has been. In the following description, the left side of the drawing is the front and the right side is the rear.

  The oil pump 2 uses a trochoid curved pump here, and an inner rotor for pump (hereinafter referred to as an outer rotor) 11 having outer teeth on a pump outer rotor (hereinafter referred to as outer rotor) 11 having inner teeth having a trochoidal tooth profile. (Hereinafter referred to as the inner rotor) 12 is engaged, and the pump rotor including the outer rotor 11 and the inner rotor 12 is eccentrically disposed in the pump housing 15 so as to be rotatable.

  The inner rotor 12 is fitted and fixed to a portion of the rotating shaft 7 that is closer to the front than the portion where the rotor 6 is formed, and rotates together with the rotating shaft 7. The outer rotor 11 has one more internal tooth than the outer teeth of the inner rotor 12, and is arranged so as to be rotatable in the pump housing 13 around a position eccentric with respect to the rotation shaft 7. Further, the inner rotor 12 rotates with its outer teeth meshing with the inner teeth of the outer rotor 11 at a part of its entire circumference, and each outer tooth substantially inscribed in the inner surface of the outer rotor 11 at various locations around the entire circumference. ing.

  Accordingly, when the rotating shaft 7 is driven to rotate by the brushless motor 3, the volume of the gap between the outer rotor 11 and the inner rotor 12 of the oil pump 2 repeatedly expands and contracts during one rotation of the rotating shaft 7. A pump operation is performed to feed oil from the import provided in the pump plate 14 and the pump housing 13 leading to the gap to the outport.

  The pump plate 14 and the pump housing 13 constituting the housing of the oil pump 2 are made of a metal nonmagnetic material (for example, aluminum die casting). A cover (lid) 15 that houses the brushless motor 3 together with the pump housing 13 is formed of a thermoplastic resin material (for example, nylon resin). The housing body of the electric oil pump device 1 is composed of the pump plate 14, the pump housing 13, and the cover 15. Here, the pump housing 13 and the cover 15 form a waterproof housing.

  The pump housing 13 is a thick plate-like one that extends in a radial direction perpendicular to the axial direction, and a pump chamber 10 having an open front is formed at the center thereof. A pump plate 14 is fixed to the front surface of the pump housing 13 via an O-ring, and the front surface of the pump chamber 10 is closed. An outer rotor 11 that constitutes the oil pump 2 is rotatably accommodated in the pump chamber 10, and an inner rotor 12 that meshes with the inner rotor 12 is disposed inside the outer rotor 11. The pump plate 14 is provided with a suction port and a discharge port penetrating in the axial direction. The cylindrical rear end opening of the pump housing 13 is closed by a cover 15.

  Next, the brushless motor 3 includes a rotating motor rotor (hereinafter referred to as “rotor”) 6 and a motor stator (hereinafter referred to as “stator”) 5 fixed to the outside of the outer peripheral surface of the rotor 6. The rotor 6 is formed by, for example, arranging a plurality of permanent magnets 8 along the circumferential direction on the outer peripheral surface of the rotating shaft 7. In the present embodiment, the permanent magnet 8 is held by a holding member provided on the outer peripheral portion of the rotor 6 body without being fixed with an adhesive. The rotating shaft 7 is a rotating shaft shared by the brushless motor 3 and the oil pump 2.

  A cylindrical portion having a smaller diameter than the cover 15 is integrally formed at the center of the rear end surface of the pump housing 13, and the rotary shaft 7 extending in the front-rear direction is cantilevered by bearings 31 and 32 provided at the rear portion in the cylindrical portion. Yes. In this example, the bearings 31 and 32 are ball bearings that are two rolling bearings adjacent to each other in the front-rear direction. The inner rings of the bearings 31 and 32 are fixed to the rotating shaft 7 and the outer rings are fixed to the cylindrical portion. . The front portion of the rotating shaft 7 passes through a hole formed in the rear wall of the pump housing 13 and enters the pump chamber 10, and the front end thereof is connected to the inner rotor 12. An oil seal 33 that seals the oil on the oil pump 2 side is provided between the rotary shaft 7 and the portion on the inner side of the cylindrical portion in front of the bearings 31 and 32.

  A rotor 6 constituting the brushless motor 3 is fixed to a rear end portion of the rotary shaft 7 protruding rearward from the cylindrical portion. The rotor 6 is formed in a cylindrical shape extending in the radial direction from the rear end of the rotating shaft 7 and surrounding the outer periphery of the bearings 31 and 32, and the permanent magnet 8 is provided on the outer periphery. More specifically, the rotor 6 includes a perforated disk part of the rotor core and a cylindrical part integrally formed on the outer periphery thereof, and the inner periphery of the disk part is fixed to the rotating shaft 7 and is arranged on the outer periphery of the cylindrical part. A permanent magnet 8 is provided. The axial position of the center of gravity of the rotating portion including the rotary shaft 7, the rotor 6 and the inner rotor 12 of the oil pump 2 is within the axial range of the bearings 31 and 32. In the present embodiment, the axial position of the center of gravity is between the two ball bearings constituting the bearings 31 and 32.

  In the stator 5, a plurality of inward salient poles (teeth) of the stator core 9 are arranged outside the outer peripheral surface of the rotor 6 through a slight air gap. A coil 17 is wound around each tooth of the stator core 9. Here, in order to insulate the coil 17 from the stator core 9, insulators 21 are mounted from both axial ends of the stator core 9.

  One end of the coil 17 is connected to a bus bar 19 molded on the insulator 21. Here, the coil connecting portion is resistance welded by fusing. Further, the three-phase bus bar 19 serving as a drive output terminal of the brushless motor 3 extends in parallel to the axial direction from the right end portion of the insulator 21.

  Further, in the electric oil pump device 1 of the present embodiment, the substrate 24 of the controller 4 for controlling the brushless motor 3 is accommodated in the control chamber 22 formed at the rear end of the pump housing 13, and the control chamber 22 is opened. The end is covered with a cover 15. On the substrate 24, this is based on an inverter circuit that converts a DC power source into AC and supplies a drive current to each coil 17 of the brushless motor 3, and information on the rotational position of the outer rotor 11 detected by a sensor such as a Hall element. A control circuit for controlling the inverter circuit is mounted. On both surfaces of the substrate 24, electronic components such as a microcomputer, an IC, a capacitor, and a coil of the control circuit unit 29 constituting the substrate 24 are mounted.

  The bus bar 19 that is each phase output terminal of the brushless motor 3 connected to each coil 17 and insulated and supported by the insulator 21 is inserted into the substrate 24 and connected to the control circuit unit 29 on the substrate 24. In addition, a connector shell (connector) 20 is provided integrally with the cover 15 on the cylindrical side surface of the cover 15, and an internal connector pin (terminal) is inserted into a through hole provided in the substrate 24 and soldered. The control circuit unit 29 on the substrate 24 is electrically connected. The connector shell 20 is fitted with a harness connector (not shown) to which a separate power source is connected.

  With the above configuration, the drive current controlled by the control circuit unit 29 is supplied to each coil 17 of the brushless motor 3. Thereby, a rotating magnetic field is generated in the coil 17, torque is generated in the permanent magnet 8, and the rotor 6 is rotationally driven. Thus, when the inner rotor 12 is driven to rotate, the outer rotor 11 is driven and rotated, and the gap between the inner teeth of the outer rotor 11 and the outer teeth of the inner rotor 12 is repeatedly expanded and contracted. Pump operation is performed to suck and discharge oil through the port.

  Here, in order to adjust a pressure difference between the inside and outside of the pump housing 13 due to a rapid temperature change of the brushless motor 3 in the usage environment, the cover 15 is connected to the space inside and outside the pump housing 13 to provide an oil pump. 2 is provided with a breathing hole extending from one surface to the opposite surface in the axial direction. Further, a seal covering the breathing hole is fixed to the inner surface of the cover 15, and this seal blocks water and allows air to pass through.

  Next, as shown in FIG. 2, the connector shell 20 is integrally formed on the cylindrical side surface of the resin cover 15 of the brushless motor 3, and the cylindrical shape extends axially forward from the inner end surface of the cover 15. The fitting portion 25 of the pump housing 13 is fitted to the holding portion 16 in which the cylindrical portion of the pump housing 13 extends rearward in the axial direction. The resin fitting portion 25 insulates the holding portion 16 of the metal pump housing 13 from the bus bar 19 molded integrally with the insulator 21 of the stator 5. In addition, a rubber annular seal member (for example, an O-ring) 27 is fitted in a circumferentially annular seal groove 26 formed in the fitting portion 25 of the cover 15, and the holding portion 16 of the pump housing 13. This is in contact with the inner peripheral surface of the pump housing 13 and seals between the holding portion 16 of the pump housing 13 and the fitting portion 25 of the cover 15. Further, the cylindrical fixing portion 28 protruding forward in the axial direction from the inner end surface of the cover 15 is in contact with the rear side (rear) end surface of the insulator 21 and both are fixed by welding. In this embodiment, it joins by the vibration welding which adds a vibration to a resin member with a pressure, and heats it.

  Next, the operation and effect of the electric oil pump device 1 according to the present embodiment configured as described above will be described.

  According to the above configuration, the outer peripheral end portion of the metal pump housing 13 of the oil pump 2 extends in the axial direction, and the stator 5 is press-fitted and fixed to the inner periphery of the cylindrical portion of the pump housing 13 shared with the housing of the brushless motor 3. Has been. The connector shell 20 is integrally formed on the side surface of the resin cover 15 of the brushless motor 3, and the cylindrical fitting portion 25 extending from the inner end surface of the cover 15 toward the axial direction motor side has a cylindrical portion of the pump housing 13. The holding part 16 extended in the axial direction anti-motor side is fitted. An annular seal member 27 is fitted in an annular seal groove 26 in the circumferential direction provided in the fitting portion 25 of the cover 15, and abuts against the inner peripheral surface of the holding portion 16 of the pump housing 13. The space between the 13 holding portions 16 and the fitting portion 25 of the cover 15 is sealed. Further, a cylindrical fixing portion 28 protruding from the inner end surface of the cover 15 toward the axial motor side is welded and fixed to the rear side end surface of the insulator 21.

  Thus, even when the motor housing portion is formed of a metal member shared with the pump housing 13, the connector shell 20 is integrally formed with the resin cover 15, so that the control chamber 22 at the motor side end of the pump housing 13 While ensuring the waterproofness of the board | substrate 24 of the accommodated controller 4, the bus-bar 19 and the holding | maintenance part 16 of the pump housing 13 can be insulated by the fitting part 25 of the resin-made cover 15, and can prevent a contact. . As a result, the brushless motor 3 can be easily assembled in the metal motor housing part, and the heat dissipation of the brushless motor 3 can be improved by making the motor housing part metal.

  The cylindrical fixing portion 28 protruding from the inner end surface of the cover 15 to the motor side is fixed to the rear end surface of the insulator 21 of the stator 5 of the brushless motor 3 by welding, so that the cover 15 is fixed to the stator of the brushless motor 3. 5 can be securely fixed. Since the motor housing part is formed integrally with the metal pump housing 13 as described above, it is not necessary to fasten the bolts between the pump housing 13 and the motor housing part, and the resin due to vibration that is likely to occur in the case of a resin housing. (For example, creep deformation) is eliminated. Furthermore, since the stator 5 is press-fitted and fixed to the inner surface of the pump housing 13 by inlay fitting, the inner diameter of the stator 5 and the rotation shaft 7 of the rotor 6 can be easily centered.

  As described above, according to the present embodiment, even when the brushless motor and the controller board are integrally formed and the brushless motor housing is formed of metal, the waterproofness of the controller is ensured and the brushless motor is secured. An electric oil pump device that can easily assemble a motor can be provided.

  Although one embodiment according to the present invention has been described above, the present invention can also be implemented in other forms.

Although the case where an internal gear pump is used as the oil pump 2 has been described in the above embodiment, the present invention is not limited to this, and a rotary pump using a vane drive or an external gear may be used.
Moreover, in the said embodiment, although the case where the brushless motor 3 was applied to the electric oil pump apparatus 1 was shown, it is not limited to this, It may apply to the other apparatus using the same brushless motor 3. Good. Furthermore, a motor with a brush can be applied.

  In the said embodiment, although the case by vibration welding was shown as a joining method of the resin materials of the insulator 21 and the cover 31, it is not limited to this, Hot plate welding, ultrasonic welding, infrared welding, etc. Or the adhesion | attachment by an adhesive agent may be sufficient.

1: electric oil pump device, 2: oil pump, 3: brushless motor (electric motor),
4: controller, 5: stator for motor, 6: rotor for motor, 7: rotating shaft,
8: permanent magnet, 9: stator core, 10: pump chamber, 11: outer rotor for pump,
12: Inner rotor for pump, 13: Pump housing, 14: Pump plate,
15: Cover (lid), 16: Holding part :, 17: Coil, 19: Bus bar,
20: Connector shell, 21: Insulator, 22: Control room, 24: Board
25: fitting part, 26: seal groove, 27: seal member, 28: fixing part, 29: control circuit part,
31, 32: bearing, 33: oil seal

Claims (2)

An oil pump,
An electric motor sharing the rotating shaft with the oil pump;
A controller that is provided adjacent to the electric motor and controls the driving of the electric motor,
A rotor provided on the rotating shaft of the electric motor;
An stator mounted on a stator core, and a stator fixed to the outside of the outer peripheral surface of the rotor by fixing a plurality of stator subassemblies each having a coil wound around the insulator in an annular shape;
A bus bar fixed to the insulator by integral molding and connected to the coil;
A metal pump housing having a holding portion extending a cylindrical outer peripheral portion on the opposite side to the oil pump in the axial direction, and the stator being fixed inside;
A control board of the controller housed in a control chamber formed at an end of the pump housing opposite to the oil pump;
A resin lid formed integrally with the connector and covering the open end of the control chamber;
An annular seal member which is mounted in a circumferential annular seal groove provided on the lid and seals between the pump housing;
A cylindrical outer peripheral portion of the lid extends in the axial direction toward the oil pump, insulates between the bus bar and the pump housing, and a fitting portion that fits with the holding portion of the pump housing;
An electric oil pump device comprising: a fixing portion that protrudes toward the oil pump in an axial direction from the inside of the lid. The electric oil pump device according to claim 1,
The electric oil pump device, wherein the fixing portion is welded and fixed to a rear side of the insulator.

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