JP2013249817A - Electric oil pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric oil pump device capable of preventing inflow of oil of a motor into a controller side by sealing a gap between a motor housing and a bus bar, wherein the motor has a structure in which the electric motor and the controller are integrally formed and in which the oil enters the inside.SOLUTION: A base end 19a of a cylindrical second bus bar 19 is press fitted into a first bus bar 18 fixed to an insulator 21 by integral molding, and a distal end 19b of the second bus bar 19 is connected to a substrate 24. A stator 5, a rotor holding member 22, and the second bus bar 19 are integrally molded with a motor housing 15. A circular annular seal member 27 is fitted into a plurality of annular seal grooves 26 formed between a cylindrical recess 25 of the motor housing 15 and the second bus bar 19, and seals a gap between the motor housing 15 and the second bus bar 19. Furthermore, a clearance 28 is formed between a recess 25 inner peripheral surface and an outer peripheral surface of a second bus bar connection part 18b of the first bus bar 18.

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, the hydraulic oil in the pump housing flows into the chamber in the motor housing that houses the rotor that rotates the electric motor through the gap between the outer periphery of the rotary shaft and the pump housing, The electric motor is cooled by contact with a stator fixed to the outside of the outer peripheral surface.

JP 2002-317772 A

  In the above-described electric oil pump device, for example, an improvement in pump efficiency can be expected by cooling the electric motor by flowing oil into the electric motor arranged near the transmission in the engine room. However, if the electric oil pump device is integrated with a controller that controls the drive of the electric motor in order to reduce the size, the interior of the motor housing passes through the boundary surface of the bus bar to which the stator coil is connected due to aging of the oil and the seal member. Inflowing oil may flow into the controller. As a result, a malfunction of the controller may occur due to deformation due to swelling of the substrate in the controller or damage to electronic components mounted on the substrate.

  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 the oil of the electric motor having a structure in which oil flows into the inside and cools down to the controller side. An object of the present invention is to provide an electric oil pump device that can prevent inflow by sealing between a motor housing and a bus bar of a stator.

  In order to solve the above-mentioned problem, the invention according to claim 1 is provided with an oil pump, an electric motor having a structure in which oil flows therein, and an electric motor that is provided adjacent to the electric motor, and drives and controls the electric motor. A controller, and the electric motor includes a rotor provided on a rotating shaft of the electric motor, an insulator mounted on the stator core, and a plurality of stator subassies in which a coil is wound around the insulator by an annular ring. A stator fixed to the outside of the outer peripheral surface of the rotor, a resin motor housing molded integrally with the stator, and a controller housed in a control chamber formed in the motor housing. A control board, and the motor housing is fixed to the insulator by integral molding, and the coil is A first bus bar connected to the first bus bar, and a base end portion having a large diameter is press-fitted in contact with an inner peripheral surface of the cylindrical portion of the first bus bar, and a tip end having a smaller diameter than the base end portion provided coaxially with the base end portion Concentric with the second bus bar formed in the control chamber of the motor housing, the second bus bar connected to the control board through a through-hole formed in the control board And an annular seal groove formed between the cylindrical recess and the annular seal member fitted into the seal groove.

  According to the above configuration, the annular sealing member is formed in the annular sealing groove formed by the second bus bar and the cylindrical recess formed coaxially with the second bus bar in the control chamber of the motor housing that houses the controller. By fitting, the seal member can be pressed with a uniform surface pressure to satisfactorily seal between the motor housing and the second bus bar. In addition, the occurrence of inflow of oil in the motor housing to the controller side can be reliably suppressed at the base end portion of the second bus bar having a large diameter, and the tip end portion having a diameter smaller than that of the base end portion can be easily provided on the control board Can connect. Thereby, the occurrence of inflow of oil in the motor housing to the controller is suppressed, and deformation of the substrate and damage of the electronic component due to swelling can be prevented.

  According to a second aspect of the present invention, in the motor device according to the first aspect, there is a gap between the outer peripheral surface of the cylindrical portion of the first bus bar and the inner peripheral surface of the concave portion formed in the motor housing. The gist is that According to the above configuration, since the gap is provided between the inner peripheral surface of the recess formed in the motor housing and the outer peripheral surface of the first bus bar into which the second bus bar is press-fitted, the resin is not in the second bus bar when the motor housing is molded. The second bus bar is formed around and does not contact the motor housing. Thereby, since the radial stress of the first bus bar generated by the press-fitting of the second bus bar can be reduced, it is possible to prevent the first bus bar from being plastically deformed.

  According to the present invention, an annular seal member is inserted into an annular seal groove formed by a bus bar and a cylindrical concave portion of a motor housing, thereby pressing the seal member with a uniform surface pressure and the bus bar and the motor. It is possible to provide an electric oil pump device that can satisfactorily seal between the housing and prevent plastic deformation of the bus bar due to press-fitting.

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 front view which shows the structure of a stator subassembly. Sectional drawing which shows the bus-bar structure of a stator.

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 showing a schematic configuration of an electric oil pump device according to an embodiment of the present invention. 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 (hereinafter referred to as a brushless motor) that drives the oil pump 2 to rotate. 3) are adjacent and integrated. The controller 4 is also incorporated in the motor housing 15. The brushless motor 3 shown in FIG. 1 is a sensorless brushless motor having a three-phase winding connected in a double star connection.

  The oil pump 2 uses a trochoid curved pump here, and an inner rotor for pumps (hereinafter referred to as “outer rotor”) 10 having outer teeth on the inner periphery of a pump outer rotor (hereinafter referred to as “outer rotor”) 10 having inner teeth having trochoidal teeth. (Hereinafter referred to as an inner rotor) 11, and the pump portion 12 is configured in which the outer rotor 10 and the inner rotor 11 are eccentrically disposed in the pump housing 15 so as to be rotatable.

  The inner rotor 11 is externally fitted and fixed to a portion (left side in FIG. 1) closer to one side than the portion where the rotor 6 is formed in the rotating shaft 7, and rotates together with the rotating shaft 7. The outer rotor 10 has one more internal tooth than the outer teeth of the inner rotor 11, and is arranged so as to be rotatable in the pump housing 15 around a position eccentric with respect to the rotation shaft 7. In addition, the inner rotor 11 rotates with its outer teeth meshing with the inner teeth of the outer rotor 10 at a part of its entire circumference, and each outer tooth substantially inscribed in the inner surface of the outer rotor 10 at various locations around the entire circumference. ing.

  Therefore, when the rotating shaft 7 is driven to rotate by the brushless motor 3, the volume of the gap between the outer rotor 10 and the inner rotor 11 of the oil pump 2 repeatedly expands and contracts during one rotation of the rotating shaft 7. A pump operation for sending oil from an import (not shown) provided on the pump plate 14 leading to the gap toward the out port is performed.

  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. The rotating shaft 7 is a rotating shaft shared by the brushless motor 3 and the oil pump 2, and both ends are rotated by bearings (for example, rolling bearings) 32 and 33 disposed inside the pump housing 13 and the rotor holding member 23. It is supported freely.

  In the stator 5, a plurality of inwardly-illustrated teeth of the stator core 9 divided through a slight air gap are arranged outside the outer peripheral surface of the rotor 6. A resin (for example, PPS) insulator 21 for insulating the coil 17 from the stator core 9 is attached to each tooth of the stator core 9 from both ends in the axial direction, and three-phase coils 17 are wound around the stator subassembly. Is formed. The stator 5 includes a plurality of stator subassemblies, and each stator subassembly is fastened and fixed by a cylindrical thin metal (for example, iron) stator ring (hereinafter referred to as a collar) 16.

  One end of the coil 17 is connected to a first bus bar (see FIG. 2) molded on the insulator 21. A coil connecting portion (not shown) engaged with the first bus bar 18 of the coil 17 is further resistance welded by fusing. The three-phase second 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.

  The stator 5, the rotor holding member 23, and the second bus bar 19 are molded integrally with the motor housing 15. Further, a resin retaining member 30 is welded to the axially outer end surface of the motor housing 15 with the second sbar 19 passing through the center thereof.

  In addition, a nut (not shown) made of metal (for example, iron, copper, etc.) is embedded in the insulator 21 mounted on the stator core 9 by insert molding. The stator 5 of the brushless motor 3 is fixed by screwing a bolt (not shown) inserted from the pump plate 14 through the pump housing 13 to a nut embedded in the insulator 21.

  The pump plate 14 and the pump housing 13 are made of a nonmagnetic material (for example, aluminum die casting). The motor housing 15 and the cover 31 that house the brushless motor 3 and the controller 4 are formed of a resin material (for example, a thermoplastic resin). The housing body of the electric oil pump device 1 includes the pump plate 14, the pump housing 13, the collar 16, the motor housing 15, and a cover 31. Here, the motor housing 15 and the cover 31 form a waterproof cover.

  Further, in the electric oil pump device 1 of this embodiment, a control board (hereinafter referred to as a board) 24 of the controller 4 for controlling the brushless motor 3 is accommodated in a control chamber 22 provided on the side opposite to the pump of the motor housing 15. The motor housing 15 is attached to the mounting portion on the outer side in the axial direction by screwing. On the substrate 24, based on the inverter circuit that converts the DC power source into AC and supplies the drive current to each coil 17 of the brushless motor 3, and the rotational position information of the outer rotor 10 detected by a sensor such as a Hall element. A control circuit unit 29 including a control circuit for controlling the inverter circuit is mounted. The inverter circuit constituting the control circuit unit 29 of the controller 4 and electronic components such as a microcomputer, a coil, and a capacitor of the control circuit are mounted on both surfaces of the substrate 24.

  The second bus bar 19 that is connected to each coil 17 and is a phase output terminal of the brushless motor 3 that is 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. A connector shell 20 is provided integrally with the motor housing 15 on the side surface of the motor housing 15, and connector pins (terminals) inside the connector shell 20 are inserted into through holes provided in the substrate 24 and soldered on the substrate 24. The control circuit unit 29 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 11 is driven to rotate, the outer rotor 10 is driven and rotated, and the gap between the inner teeth of the outer rotor 10 and the outer teeth of the inner rotor 11 is repeatedly expanded and contracted. Pump operation is performed to suck and discharge oil through the port.

  Next, FIG. 2 is a front view showing the configuration of the stator subassembly, and FIG. 3 is a cross-sectional view showing the bus bar configuration of the stator. As shown in FIG. 2, the end portion of the coil 17 is connected to a coil connection portion 18 a that is one end portion of the first bus bar 18 molded in the insulator 21 attached to the stator core 9. A second bus bar 19 serving as a phase output terminal of the brushless motor 3 is electrically connected to a cylindrical second bus bar connection portion 18b which is the other end portion of the first bus bar 18 to form a bus bar. The first bus bar 18 is formed with a coil connection part 18a having a slit-like part opened at one end and a cylindrical second bus bar connection part 18b at the other end, and the cylindrical second bus bar 19 is The first bus bar 18 is fitted in contact with the inner peripheral surface of the cylindrical portion of the second bus bar connecting portion 18b. The first and second bus bars 18 and 19 are formed into a predetermined shape by processing a metal member (for example, high-strength copper).

  As shown in FIG. 3, the second bus bar 19 has a large-diameter base end 19 a that forms an annular seal groove 26 between the second bus bar 19 and a cylindrical recess 25 formed concentrically, and a base end It is provided coaxially with the portion 19a and is formed from a distal end portion 19b having a smaller diameter than the proximal end portion 19a. The second bus bar 19 has a base end portion 19a fitted into the first bus bar 18 in the motor housing 15 formed in a cylindrical shape and a tip end portion 19b inserted through the substrate 24 formed in a pin shape. Further, a gap 28 is provided between the outer peripheral surface of the base end portion 19 a of the second bus bar 19 and the inner peripheral surface of the recess 25 formed in the motor housing 15, and the base end portion 19 a is the second bus bar of the first bus bar 18. It is press-fitted and fixed in the opening of the connecting portion 18b.

  A rubber annular seal member (for example, an O-ring) 27 is fitted into a plurality (for example, three) of annular seal grooves 26 formed on the outer end surface of the motor housing 15, so that the second bus bar 19 Abutting on the outer peripheral surface of the cylindrical base end portion 19 a is sealed between the motor housing 15 and the second bus bar 19. Further, a retaining member 30 for preventing the seal member 27 from coming off closes the opening end of the recess 25 and is welded to the motor housing 15.

Next, a method for manufacturing the electric oil pump device of the present invention will be described.
First, a plurality of stator subassies are press-fitted into the collar 16. In this embodiment, the number of stator sub-assies is six. Subsequently, referring to FIG. 2, the cylindrical base end portion 19 a of the second bus bar 19 is press-fitted into the cylindrical bus bar connection portions 18 b of the three first bus bars 18 of the stator 5. And it correct | amends so that the axial center of the 2nd bus-bar 19 may become parallel to an axial direction.

  Next, the stator 5 and the rotor holding member 23 aligned with each other are placed on the lower mold of the mold on the fixed side, and the upper mold on the movable side is mold-matched to form the mold. Subsequently, resin is injected into the mold to mold the motor housing 15. The upper mold includes a convex portion for forming an annular seal groove 26 surrounding the base end portion 19 a of the second bus bar 19 on the outer end surface of the motor housing 15, and a fitting portion for accommodating the second bus bar 19. And a cylindrical recess 25 is formed in the control chamber 22, and finally a seal groove 26 is formed.

  Referring to FIG. 2, an annular seal member 27 is fitted into an annular seal groove 26 formed in the cylindrical recess 25 of the motor housing 15 and surrounding the cylindrical base end portion 19 a of the second bus bar 19. Then, a resin retaining member 30 that closes the opening end of the cylindrical recess 25 is fixed to the opening end by vibration welding. With the front end 19b of the second bus bar 19 inserted into the through hole of the board 24 of the controller 4, the board 24 is integrally screwed to the mounting portion on the outer end surface of the motor housing 15, and then soldered and electrically connected. To do.

  The motor housing 15 illustrated in FIG. 1 is formed through the above steps. Subsequently, the motor housing 15 and the cover 31, both of which are made of a resin material, are joined by spin welding. An annular welding rib is formed on the back side of the cover 31 that covers the opening of the motor housing 15, and the welding rib is heated and melted while rotating the cover 31, and is fixed to the motor housing 15 of the counterpart component. It is welded by pressing against the concave part. Furthermore, the electric oil pump device 1 is assembled by inserting the rotor 6 into the central portion of the motor housing 15 and fixing the pump housing 13 and the pump plate 14 to the mounting stator 5.

  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 coil connecting portion 18 a at one end of the first bus bar 18 provided integrally with the insulator 21 is connected to the coil 17, and the outer periphery of the second bus bar connecting portion 18 b at the other end of the first bus bar 18. The second bus bar 19 in which the large-diameter base end portion 19a of the second bus bar 19 is press-fitted in contact with the surface and the tip end portion 19b of the second bus bar 19 having a smaller diameter than the base end portion 19a is connected to the substrate 24 is the motor housing. 15 is molded. A cylindrical recess 25 and a second bus bar 19 formed concentrically with the second bus bar 19 in the control chamber 22 of the motor housing 15 in a state where the tip 19b of the second bus bar 19 can penetrate the through hole of the substrate 24. The control chamber 22 is sealed by fitting an annular seal member 27 into an annular seal groove 26 formed by the cylindrical base end portion 19a.

  The second bus bar 19 is corrected so that the axis of the seal groove 26 of the motor housing 15 and the second bus bar 19 coincide with each other. Then, after molding the stator 5 and the motor housing 15, a seal member 27 is fitted into the seal groove 26 to seal between the motor housing 15 and the second bus bar 19. Here, the inner peripheral surface of the seal groove 26 and the outer peripheral surface of the cylindrical base end portion 19 a of the second bus bar 19 are sealed against oil by an annular seal member 27. Further, the substrate 24 of the controller 4 is fixed to the mounting portion on the outer end surface of the motor housing 15 and is connected by directly soldering the front end portion 19b of the second bus bar 19 through which the through hole of the substrate 24 is inserted.

  As a result, the motor housing 15 can be molded by aligning the axis of the second bus bar 19 and the axis of the annular seal groove 26 into which the annular seal member 27 is fitted. The surface pressure that presses the member 27 becomes uniform, and the inflow of oil into the control chamber 22 can be prevented. Further, the sealing member 27 can be prevented from coming off by welding the retaining member 30 to the opening end of the cylindrical recess 25. For this reason, the sealing performance with respect to oil can be improved, and generation | occurrence | production of the inflow to the controller 4 via the 2nd bus bar 19 of the oil in the motor housing 15 is suppressed favorably. As a result, deformation of the substrate 24 and damage to the electronic component due to swelling can be prevented.

  Further, since the gap 28 is provided between the inner peripheral surface of the cylindrical recess 25 of the motor housing 15 and the surface of the bus bar connecting portion 34 of the first bus bar 18 into which the second bus bar 19 is press-fitted, a resin is formed when the motor housing 15 is molded. The material is formed around the second bus bar connection portion 18 b of the first bus bar 18. For this reason, the second bus bar 19 does not come into contact with the motor housing 15, and the radial stress applied to the cylindrical second bus bar connecting portion 18 b of the first bus bar 18 by the press-fitting of the second bus bar 19 can be reduced. Furthermore, the use of high-strength copper for the members of the first and second bus bars 18 and 19 can secure the safety factor at the maximum tightening allowance, and the surface stress generated by press-fitting can be reduced by increasing the press-fitting diameter. it can. Thereby, since it can prevent that the 2nd bus-bar connection part 18b of the 1st bus-bar 18 deforms plastically, generation | occurrence | production of the distortion of the 1st bus-bar 18 by a stress and generation | occurrence | production of a fracture | rupture can be avoided.

  Furthermore, since the controller 4 installed in the passenger compartment and controlling the drive of the brushless motor 3 is integrated in the motor housing 15, there is no increase in cost due to the harness, and there is an influence of noise from the outside. The operation of the controller 4 does not become unstable, and the controller 4 does not adversely affect the outside. That is, a harness for connecting the brushless motor 3 and the controller 4 is not required, and the controller 4 can be integrated into the electric oil pump device 1 to further reduce the size.

  As described above, according to the present embodiment, the annular seal member is inserted into the annular seal groove formed by the second bus bar and the cylindrical concave portion of the motor housing, so that the seal member is made uniform. It is possible to provide an electric oil pump device that can press well with pressure to seal well between the second bus bar and the motor housing and can prevent plastic deformation of the first bus bar that press-fits the second bus bar.

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

In the above embodiment, the controller 4 is arranged in the axial direction of the oil pump 2 and integrated with the brushless motor 1. However, the present invention is not limited to this, and the brushless motor 3 is not limited to this. You may install adjacent to the radial direction.
Moreover, although the case where the internal gear pump was used as the oil pump 2 was shown in the said embodiment, it is not limited to this, The rotary pump using a vane drive, an external gear, etc. may be sufficient.
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 spin welding was shown as a joining method of the resin materials of the motor housing 15 and the cover 31, it is not limited to this, Hot plate welding, ultrasonic welding, vibration welding, Infrared welding or the like, or adhesion using an adhesive may be used. Moreover, the joining method of the motor housing 15 and the resin retaining member 30 is not limited to vibration welding, and may be adhesion using an adhesive.
Furthermore, although the case where the board | substrate 24 was fixed to the motor housing 15 by screwing was shown in the said embodiment, it is not limited to this, For example, you may fix using a snap-type spacer.

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 DESCRIPTION OF SYMBOLS 10: Outer rotor for pumps, 11: Inner rotor for pumps, 12: Pump part, 13: Pump housing, 14: Pump plate, 15: Motor housing, 16: Collar (stator ring), 17: Motor coil, 18, 18a, 18b: 1st bus bar, coil connection part, 2nd bus bar connection part, 19, 19a, 19b: 2nd bus bar, base end part, tip part, 20: Connector shell, 21: Insulator, 22: Control room,
23: Rotor holding member, 24: Substrate, 25: Recess, 26: Seal groove, 27: Seal member, 28: Gap, 29: Control circuit part, 30: Retaining member, 31: Cover, 32, 33: Bearing

Claims (2)

An oil pump,
An electric motor with a structure in which oil flows into the interior;
A controller that is provided adjacent to the electric motor and controls the driving of the electric motor,
The electric motor includes a rotor provided on a 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 subassies each having a coil wound around the insulator in an annular shape by a stator ring;
A resin motor housing molded integrally with the stator;
A control board of the controller housed in a control chamber formed in the motor housing,
The motor housing is
A first bus bar fixed to the insulator by integral molding and connected to the coil;
A base end portion having a large diameter is press-fitted in contact with an inner peripheral surface of the cylindrical portion of the first bus bar, and a tip portion having a smaller diameter than the base end portion provided coaxially with the base end portion is formed in the control board. A second bus bar penetrating the through hole and connected to the control board;
An annular seal groove formed between the second bus bar and a cylindrical recess formed concentrically with the second bus bar formed in the control chamber of the motor housing;
An electric oil pump device comprising: an annular seal member fitted into the seal groove. The electric oil pump device according to claim 1,
An electric oil pump device characterized in that a gap is provided between an outer peripheral surface of a cylindrical portion of the first bus bar and an inner peripheral surface of the recess formed in the motor housing.

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