JP2013199875A - Electric oil pump device - Google Patents

Abstract

An electric oil pump device that can be mounted on a vehicle without increasing the motor in the radial direction is provided.
A pump housing (13) of a metal oil pump (2) and a motor housing (15) of a brushless motor (3) are inserted into a motor housing (15) via a metal fastening ring (22) which is molded so as to protrude in the axial direction toward the oil pump. The bolt 19 inserted from the pump plate 14 side of the oil pump 2 is fastened and fixed. At this time, the bolt 19 is disposed inside the outer diameter of the brushless motor 3. Further, the axial force of the bolt 19 is received by the fastening ring 22. The inner ring surface of the fastening ring 22 is tapered and covered with resin, and the O-ring 26 is mounted radially inward from the position of the bolt 19 between the taper inner wall surface and the shoulder and small diameter portion of the step of the pump housing 13. Is inserted.
[Selection] Figure 2

Description

  The present invention relates to an electric oil pump device.

  Conventionally, a specific example of an electric oil pump device includes a combination of an oil pump that circulates fluid (oil) and an electric motor that drives the oil pump. The electric motor includes a rotating rotor and a stator fixed to the outside of the outer peripheral surface of the rotor. The rotor is formed by arranging a plurality of permanent magnets along the circumferential direction on the outer peripheral surface of the rotation drive shaft, and the rotation drive shaft is a rotation shaft shared by the electric motor and the oil pump. In addition, an electric oil pump device has been proposed in which a bolt inserted from a motor housing is screwed to an oil pump housing to fix the stator of the electric motor (for example, see Patent Document 1). Here, the stator of the electric motor is formed by winding a coil around an insulator attached to a core, and is integrally formed with a resin-molded motor housing.

JP 2003-129966 A

  However, in the electric oil pump device, when the oil pump and the electric motor are fastened with bolts, it is necessary to provide a flange around the outside of the motor outer diameter of the motor housing. Thereby, when mounting in a vehicle, a flange may protrude and may interfere with a vehicle. Also, in order to prevent so-called creep deformation due to aging etc. of the contact part between the resin of the motor housing and the metal surface of the pump housing, it is necessary to take measures to attach the metal ring to the flange and insert the bolt. is there. Further, water may enter the motor from the outside through the boundary surface between the resin of the motor housing and the metal surface of the pump housing.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electric oil pump device that can improve mountability on a vehicle without enlarging the motor in the radial direction.

  In order to solve the above-mentioned problem, an invention according to claim 1 is directed to an oil pump in which a pump rotor is rotatably supported around a rotation axis in a pump chamber formed between a pump plate and a pump housing; An electric motor provided adjacent to the oil pump in the direction of the rotation axis and rotating the pump rotor, and an outer peripheral edge of the pump housing is disposed between the pump plate and the motor housing of the electric motor. An electric oil pump device sandwiched by a metal annular fixing integrated by insert molding with a pump side outer peripheral portion of the resin motor housing so that a contact surface that contacts the outer peripheral edge portion is exposed. The annular fixing member is formed through a member, a bolt hole drilled in the rotational axis direction in the pump plate and the outer peripheral edge portion. Internal thread and screwed the pump plate, and summarized in that includes a plurality of fastening screw members for fastening the outer peripheral portion and the annular fixing member.

  According to a second aspect of the present invention, in the electric oil pump device according to the first aspect, the annular fixing member has a tapered inner circumferential surface whose diameter decreases toward the electric motor side coaxially with the rotation axis. The taper inner peripheral surface is covered with the insert-molded resin from the small diameter side to the large diameter side, and the pump housing has a step formed so as to face the taper inner peripheral surface in the axial direction. The gist is that a sealing member is sandwiched between the shoulder portion and the small diameter portion of the step and the tapered inner peripheral surface.

  According to a third aspect of the present invention, in the electric oil pump device according to the second aspect, a fitting inner peripheral surface extending in the direction of the rotation axis from the large diameter side of the tapered inner peripheral surface of the annular fixing member; The gist is that the fitting outer peripheral surface extending in the direction of the rotation axis from the small diameter side of the outer peripheral edge of the pump housing is inlay fitted.

  According to the first aspect of the present invention, the metal pump plate and the pump housing are fastened and fixed by the plurality of fastening screw members to the metal annular fixing member that is insert-molded in the motor housing of the resin electric motor. Therefore, the electric motor does not increase in the radial direction, and the mountability of the electric oil pump device on the vehicle is improved. In addition, creep deformation of the resin motor housing that contacts the metal pump housing can be prevented, and entry of water from the outside can be prevented.

  According to the invention which concerns on Claim 2, a taper surface is provided in the inner peripheral side of the cyclic | annular fixing member, and the taper inner peripheral surface is coat | covered with resin toward the large diameter side from the small diameter side. Since the sealing member is sandwiched between the taper inner peripheral surface coated with the resin and the shoulder and the small diameter portion of the step of the pump housing, the resin covering the taper inner peripheral surface exists outside the sealing member. Intrusion of water from the outside of the electric motor is eliminated.

  According to the invention which concerns on Claim 3, the fitting inner peripheral surface of the inner peripheral side of a cyclic | annular fixing member and the fitting outer peripheral surface of the outer peripheral part of a pump housing are inlay fitted, and it fits coaxially with a rotation center. Therefore, the alignment accuracy of the pump housing and the motor housing is improved.

1 is a front view of an electric oil pump device according to an embodiment of the present invention. The longitudinal cross-sectional view which shows schematic structure of the electric oil pump apparatus seen from the XX direction in FIG. These are front views of the fixing member which concerns on one Embodiment of this invention. FIG. 3 is an axial side view of a fixing member.

Next, an electric oil pump device according to an embodiment of the present invention will be described with reference to the drawings.
1 is a front view of an electric oil pump device according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing a schematic configuration of the electric oil pump device viewed from the XX direction in FIG. 1, and FIG. FIG. 4 is a front view of the fastening ring 22 according to the embodiment of the present invention, and FIG. In the following description, the left side of the drawing is the front and the right side is the rear. As shown in FIGS. 1 and 2, an electric oil pump device 1 is used as a hydraulic pump for an automobile transmission, and rotates an oil pump (for example, an internal gear pump) 2 and an oil pump 2 (hereinafter referred to as an oil pump 2). (Referred to as a brushless motor) 3 is adjacent to and unitized (integrated). Note that the brushless motor 3 shown in FIG. 2 is a sensorless brushless motor having three-phase windings connected in a double star connection. The electric oil pump device 1 is screwed and fixed through a mounting hole 35 to a transmission case (not shown) via a plurality of flange portions protruding from the end face of the pump plate 14. In this embodiment, the bolts are fastened with three bolts (not shown) arranged in the circumferential direction with respect to the center of the axis.

  The pump plate 14, the pump housing 13, and the fastening ring (annular fixing member) 22 constituting the housing 16 of the oil pump 2 are formed of a metal nonmagnetic material (for example, aluminum die casting). The motor housing 15 and the cover 31 that house the brushless motor 3 are formed of a thermoplastic resin material (for example, nylon resin). The housing body of the electric oil pump device 1 includes the pump plate 14, the pump housing 13, the fastening ring 22, the motor housing 15, and the cover 31. Here, the motor housing 15 and the cover 31 form a waterproof cover.

  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 is engaged, and a pump chamber 12 is configured in which the outer rotor 10 and the inner rotor 11 are eccentrically disposed in a pump housing 13 so as to be rotatable.

  The inner rotor 11 is externally fitted and fixed to a portion of the rotary drive shaft (rotary shaft) 7 that is closer to the front than the portion where the rotor 6 is formed, and rotates with the rotary drive 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 13 around a position eccentric with respect to the rotation drive 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 rotary drive shaft 7 is rotationally driven by the brushless motor 3, the volume of the gap between the inner teeth of the outer rotor 10 of the oil pump 2 and the outer teeth of the inner rotor 11 is between one rotation of the rotary drive shaft 7. Since the enlargement and reduction are repeated, a pump operation is performed in which oil is sent from an import (not shown) provided in the pump plate 14 leading to the gap toward the outport.

  The motor housing 15 has a cylindrical shape, and its front end is fixed to a portion near the outer periphery of the rear surface of the pump housing 13 via an oil seal 27. The rear end opening of the motor housing 15 is closed by the case 31.

  The pump housing 13 has a thick plate shape that expands in the radial direction, and a pump chamber 12 having a front opening is formed at the center thereof. The pump plate 14 is fixed to the front surface of the pump housing 13 via an O-ring 25 and the front surface of the pump chamber 12 is closed. An outer rotor 10 constituting the oil pump 2 is rotatably accommodated in the pump chamber 12, and an inner rotor 11 that meshes with the outer rotor 10 is disposed inside the outer rotor 10. The pump plate 14 is provided with a suction port 23 and a discharge port 24 shown in FIG. 1 penetrating in the axial direction.

  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 arranging, for example, a plurality of permanent magnets 8 along the circumferential direction on the outer peripheral surface of the rotary drive shaft 7. The rotation drive shaft 7 is a rotation shaft shared by the brushless motor 3 and the oil pump 2.

  A cylindrical portion having a smaller diameter than the motor housing 15 is integrally formed at the center of the rear end surface of the pump housing 13, and the rotary drive shaft 7 extending in the front-rear direction is cantilevered by bearings 32 and 33 provided at the rear portion in the cylindrical portion. Has been. In this example, the bearings 32 and 33 are ball bearings which are two rolling bearings adjacent to each other in the front and rear, the inner ring of each of the bearings 32 and 33 is fixed to the rotary drive shaft 7, and the outer ring is fixed to the cylindrical portion. Yes. The front portion of the rotary drive shaft 7 passes through a hole formed in the rear wall of the pump housing 13 and enters the pump chamber 12, and the front end thereof is connected to the inner rotor 11. An oil seal 27 is provided between a portion of the cylindrical portion on the front side of the bearings 32 and 33 and the rotary drive shaft 7.

  A rotor 6 constituting the brushless motor 3 is fixed to a rear end portion of the rotary drive shaft 7 protruding rearward from the cylindrical portion. The rotor 6 has a cylindrical shape that extends in the radial direction from the rear end of the rotary drive shaft 7 and surrounds the outer circumferences of the bearings 32 and 33, and a permanent magnet 8 is provided on the outer circumference. More specifically, the rotor 6 includes a perforated disk portion of the rotor core 28 and a cylindrical portion integrally formed on the outer periphery thereof, and the inner periphery of the disk portion is fixed to the rotary drive shaft 7, and the cylindrical portion Permanent magnets 8 are provided on the outer periphery. The axial position of the center of gravity of the rotating portion including the rotary drive shaft 7, the rotor 6 and the inner rotor 11 of the oil pump 2 is within the axial range of the bearings 32 and 33. In the present embodiment, the axial direction position of the center of gravity is between the two ball bearings constituting the bearings 32 and 33.

  In the stator 5, a plurality (for example, six in the present embodiment) 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 forming. The stator 5 is composed of the plurality of stator subassemblies, is molded integrally with the motor housing 15, and is fixed to the inner periphery of the motor housing 15.

  A connector shell 30 shown in FIG. 1 is provided integrally with the motor housing 15 on the side surface of the motor housing 15, and the end of the coil 17 is electrically connected to a connector pin inside the connector shell 30 by wiring.

  On the end surface of the motor housing 15 on the pump side, a cylindrical thin metal fastening ring 22 is disposed so as to protrude in the axial direction and is embedded by insert molding. The inner peripheral surface of the fastening ring 22 is formed with a tapered inlay on which a film made of a resin coating is uniformly formed, and is in contact with the outer peripheral surface of the pump housing 13. Here, a groove portion is formed on the outer peripheral surface side of the pump housing 13, and an O-ring 26 is attached to the groove portion to maintain the sealing performance with the motor housing 15. A plurality of bolts (fastening screw members) 19 inserted from the pump plate 14 side through the bolt holes in the outer peripheral edge of the pump plate 14 and the pump housing 13 are provided on the fastening ring 22 embedded in the motor housing 15 (for example, The stator 5 of the brushless motor 3 is fixed to the pump housing 13 by being inserted into and screwed into four screw holes (female screws) 20 in this embodiment. In the present embodiment, four screw holes 20 are arranged at equal intervals in the circumferential direction with respect to the rotation center.

  Further, in the electric oil pump device 1 of this embodiment, a controller (not shown) for controlling the brushless motor 3 is connected to a connector pin in the connector shell 30 of the motor housing 15 via a harness. The controller includes 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 a control circuit unit that includes a control circuit that controls the inverter circuit.

  The motor housing 15 and the cover 31, both of which are made of a resin material, are joined here by applying a sealing material to the mating surfaces. Further, 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 fastening ring 22.

  With the above configuration, a drive current controlled by an external controller 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, the operation and effect of the electric oil pump device 1 of the present embodiment configured as described above will be described.

  According to the above configuration, the pump plate 14 of the metal oil pump 2, the pump housing 13, and the resin motor housing 15 of the brushless motor 3 are axially coaxial with the rotation center on the oil pump side in the motor housing 15. The bolt 19 inserted from the pump plate 14 side is fastened and fixed at the screw hole 29 of the fastening ring 22 through a metal fastening ring 22 that is projected and molded in the direction. At this time, the bolt 19 is disposed inside the outer diameter of the brushless motor 3. Further, the axial force of the bolt 19 is received by the fastening ring 22. Further, a tapered surface is provided on the inner peripheral surface of the fastening ring 22, and the shoulder of the step of the pump housing 13 facing the tapered inner peripheral surface is covered with resin from the small diameter side to the large diameter side of the tapered inner peripheral surface. The pump housing 13 and the fastening ring 22 are fitted together by sandwiching an O-ring 26 attached radially inward from the position of the bolt 19 between the small diameter portion and the tapered inner peripheral surface. Furthermore, the fitting inner peripheral surface of the taper inner peripheral surface of the fastening ring 22 and the fitting outer peripheral surface of the outer peripheral edge portion of the pump housing 13 are fitted together and fitted coaxially with the rotation center.

  As a result, the electric oil pump device 1 does not increase in the radial direction of the brushless motor 3. Further, creep deformation of the resin motor housing 15 caused by contact with the metal pump housing 13 can be prevented. In addition, since the resin that covers the tapered inner peripheral surface of the fastening ring 22 exists outside the O-ring 26, water does not enter the brushless motor 3 from the outside. Further, since the cylindrical portion of the fastening ring 22 is an inlay, the accuracy of centering of the outer rotor 10 and the inner rotor 11 of the pump housing 13 and the stator 5 of the motor housing 15 is improved. As a result, the sealing property between the pump housing 13 of the oil pump 2 and the motor housing 15 can be secured, the rotors 10 and 11 in the pump chamber 12 and the motor stator 5 can be easily assembled, and the brushless motor 3 Mountability to a vehicle is improved by downsizing in the radial direction.

  As described above, according to the present embodiment, it is possible to provide an electric oil pump device that can be mounted on a vehicle without increasing the motor in the radial direction.

  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-described embodiment, the four screw holes 20 are arranged in the fastening ring 22 at equal intervals in the circumferential direction with respect to the rotation center and fastened with the bolts 19. If the force is restricted, the number may be smaller (for example, three are arranged at equal intervals of 120 degrees).

  Moreover, although the case where the internal gear type pump was used as the oil pump 2 was shown in the said embodiment, not only this but the rotary pump using a vane drive, an external gear, etc. may be sufficient. Further, as an inscribed gear pump, an inner tooth is provided on the inner peripheral side of the outer rotor 10, and it is eccentrically rotated while meshing with the inner rotor 11 provided with the outer teeth, so that it is an inscribed portion between the outer rotor 10 and the inner rotor 11. As long as the volume of the partitioned gap is an internal gear pump that repeats expansion and contraction, it is not necessarily limited to the trochoid curve type pump as described above. Further, the inner teeth of the outer rotor 10 and the outer teeth of the inner rotor 11 are not necessarily formed in a clear so-called tooth shape, and may be protrusions, protrusions, or engaging portions.

  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, You may apply to the other apparatus using the same brushless motor 3. FIG. Furthermore, a motor with a brush can be applied.

  Moreover, in the said embodiment, although the case where the several permanent magnet 8 was arrange | positioned and fixed to the outer peripheral part of the rotational drive shaft 7 was shown as the rotor 6 of the brushless motor 3, what fixed the ring-shaped permanent magnet was shown. You may make it use.

  In the above-described embodiment, the case where the controller is provided separately from the brushless motor 3 has been described. However, the present invention is not limited to this, and the controller is incorporated in the housing of the electric oil pump device 1 and the substrate is located behind the motor housing 15. The structure fixed to an edge part may be sufficient.

1: electric oil pump device, 2: oil pump, 3: brushless motor (electric motor), 5: stator for motor, 6: rotor for motor, 7: rotary drive shaft (rotary shaft), 8: permanent magnet, 9: Stator core, 10: outer rotor for pump, 11: inner rotor for pump, 12: pump chamber, 13: pump housing, 14: pump plate, 15: motor housing, 16: housing, 17: motor coil, 19: bolt (fastening screw member) ), 20: screw holes for bolts (female threads), 21: insulator, 22: fastening ring (annular fixing member),
23: suction port, 24: discharge port, 25, 26: O-ring, 27: oil seal, 28: rotor core, 30: connector shell, 31: cover, 32, 33: bearing, 34: fastening ring hole, 35: mounting hole

Claims (3)

An oil pump in which a pump rotor is rotatably supported around a rotation axis in a pump chamber formed between a pump plate and a pump housing;
An electric motor provided adjacent to the oil pump in the direction of the rotation axis and driving the pump rotor to rotate,
An electric oil pump device sandwiching an outer peripheral edge of the pump housing between the pump plate and a motor housing of the electric motor,
A metal annular fixing member integrated by insert molding with the pump side outer peripheral portion of the resin-made motor housing so that a contact surface that contacts the outer peripheral edge portion is exposed;
The pump plate, the outer peripheral edge portion, and the annular fixing member are threaded into a female screw formed in the annular fixing member through a bolt hole drilled in the rotation axis direction in the pump plate and the outer peripheral edge portion. An electric oil pump device comprising: a plurality of fastening screw members for fastening The electric oil pump device according to claim 1,
The annular fixing member includes a tapered inner peripheral surface that is coaxial with the rotation axis and decreases in diameter toward the electric motor, and the tapered inner peripheral surface is insert-molded from the small diameter side toward the large diameter side. Covered with resin,
The pump housing is formed with a step so as to face the tapered inner peripheral surface in the axial direction,
An electric oil pump device characterized in that a seal member is sandwiched between the shoulder and small diameter portion of the step and the tapered inner peripheral surface. In the electric oil pump device according to claim 2,
A fitting inner peripheral surface extending in the rotation axis direction from the large diameter side of the tapered inner peripheral surface of the annular fixing member, and a rotation axis direction extending from a small diameter side of the outer peripheral edge portion of the pump housing. An electric oil pump device characterized in that the fitting outer peripheral surface is inlay fitted.

Images