JP2008092759A - Electric motor and electric pump unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reliable electric motor, where the axial vibration and circumferential rotation of a stator core following the rotation of a rotor are suppressed successfully for preventing the transmission loss of driving force at a motor section effectively, and to provide an electric pump unit using the electric motor. <P>SOLUTION: The electric motor 1 comprises: a motor section 10, having a stator core 13 provided in and around a rotor 12, and an insulator 15 fixed to the stator core 13 to insulate the stator core 13 from a coil 14 wound around the stator core 13; and a motor case 11 formed in a bottomed, square cylindrical shape for storing the motor section 10. In the motor case 11, the stator core 13 is formed on the inner surface 11b, and a partition wall 11a for separating space for storing the motor section 10 from an axial outside is provided integrally. A screw 18 is used for fixing the insulator 15 to the partition wall 11a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric motor and an electric pump unit in which the electric motor and a pump unit that sucks and discharges liquid are unitized.

  In recent years, so-called hybrid cars that have a low environmental impact have attracted attention, and many models that have already entered the practical stage and have been mass-produced have appeared. Since such vehicles that use electric power for running perform intermittent operation of the engine, it is necessary to replace the drive source with an electric motor for the auxiliary equipment such as a pump that has been driven by an endless belt that has been stretched over the engine. There is.

  As this type of electric pump, an electric pump unit is proposed in which a pump part for circulating oil (liquid) and a motor part for driving the pump part are unitized, and a rotating shaft of the pump part and the electric motor part is proposed. As a result, the number of parts is reduced, the electric pump unit is made compact, and the manufacturing cost is reduced.

  In such an electric pump unit, for example, as shown in FIG. 3, the pump unit 2 is housed in a pump case 20 made of aluminum die casting, and rotates by meshing with an outer rotor 21 having a trochoidal tooth profile and the outer rotor 21. The inner rotor 22 is configured to be capable of sucking and discharging fluid such as oil (see Patent Document 1). On the other hand, the motor unit 10 ′ is housed in a motor case 11 ′ made of aluminum die casting that is integrated with the pump case 20, and supports the inner rotor 22 of the pump unit 2 and the rotor 12 that passes through the pump case 20. It is comprised so that the said pump part 2 may be driven via.

  The motor unit 10 ′ includes a rotor 12, a stator core 13 disposed around the rotor 12, a coil 14 wound around the stator core 13, and the stator core 13 to insulate the stator core 13 from the coil 14. And an insulator 15 fixed to the head. An electric motor 1 ′ is constituted by such a motor unit 10 ′ and a cylindrical motor case 11 ′ that accommodates the motor unit 10 ′.

In the electric motor 1 ′, the stator core 13 receives axial and circumferential forces as the rotor 12 rotates. As a result, when the stator core 13 vibrates in the axial direction or follows the rotor 12 and rotates in the circumferential direction with respect to the motor case 11 ′, the driving force transmitted from the motor unit 10 ′ to the pump unit 2 is transmitted. Loss occurs. For this reason, from the viewpoint of preventing the transmission loss, the stator core 13 is press-fitted into the motor case 11 ′, or the adhesive 6 is interposed between the motor case 11 ′ and the stator core 13 (see FIG. 3). The members 13 and 11 ′ are fixed.
JP 2001-182669 A, FIG.

  However, in the above-described fixing method, in the case of press-fitting, depending on the degree of press-fitting, suppression of vibration in the axial direction may be insufficient. In the case of using an adhesive, peeling may occur between the stator core 13 and the motor case 11 ′ due to variations in bonding conditions and the like. And these may impair the reliability (performance and durability) of the electric motor 1 ′.

  On the other hand, in the method of fixing the stator core 13 to the motor case 11 ′ by so-called “shrink fitting”, the motor case 11 ′ is often made by aluminum die casting as described above, and the motor case 11 is thermally expanded or contracted. Stress concentration may occur in the corner portion of the inner frame of ′, and the corner portion may be cracked or damaged.

  The present invention has been made to solve the above-described problems, and its purpose is to drive the motor unit by effectively suppressing the axial vibration and circumferential rotation of the stator core accompanying the rotation of the rotor. An object of the present invention is to provide an electric motor that effectively prevents power transmission loss and realizes high reliability, and an electric pump unit using the electric motor.

  In order to solve the above-mentioned problems, the invention according to claim 1 insulates the stator core from the rotor, a stator core disposed around the rotor, a coil wound around the stator core, and the coil. A motor part having an insulator fixed to the stator core, and a cylindrical motor case that accommodates the motor part, and the motor case has the stator core fixed to an inner surface thereof, and The gist of the present invention is that the insulator is fixed to the partition wall with a screw in an electric motor integrally having a partition wall that partitions the space for housing the motor portion and the outside in the axial direction.

  According to this configuration, the insulator fixed to the stator core is fixed to the partition wall integrated with the motor case via the screw. For this reason, the stator core is fixed to the motor case via the insulator, and the axial vibration and the circumferential rotation of the stator core accompanying the rotation of the rotor are effectively suppressed.

The gist of the invention described in claim 2 is that, in the electric motor according to claim 1, the stator core is fixed to the inner surface of the motor case via an adhesive.
According to this configuration, the stator core is fixed to the inner wall of the motor case via the adhesive, in addition to being fixed to the partition wall integrated with the motor case via the insulator and the screw. For this reason, the stator core is more securely fixed to the motor case, and the axial vibration and the circumferential rotation of the stator core accompanying the rotation of the rotor are further effectively suppressed.

  According to a third aspect of the present invention, in the electric motor according to the first or second aspect, the motor case is formed in a bottomed rectangular tube shape, and the partition wall is formed by a bottom portion of the motor case. It is a summary.

  According to this configuration, since the motor case is formed in a bottomed rectangular tube shape, it becomes easy to dispose a square circuit board on the outer end face side of the motor case. In addition, since the partition wall to which the stator core is fixed via the insulator and the screw is formed by the bottom portion of the motor case, the stator core can be reliably and stably fixed to the motor case.

  According to a fourth aspect of the present invention, in the electric motor according to any one of the first to third aspects, the insulator is used by using screws at two locations where the insulator is positioned in the vicinity of the left and right side surfaces of the motor case. The gist is that it is fixed to the partition wall.

  According to this configuration, since the stator core is fixed to the partition wall integrated with the motor case at the two positions located near the left and right side surfaces of the motor case via the insulator and the screw, the rotation of the rotor is particularly effective. The accompanying rotation (turning) of the stator core can be more effectively suppressed.

The gist of the invention according to claim 5 is that, in the electric motor according to claim 4, the screw is screwed into a nut embedded in the insulator.
According to this configuration, since the screw inserted through the partition wall is screwed into the nut embedded in the insulator, the stator core can be reliably and stably fixed to the motor case with a simple configuration.

  The invention described in claim 6 is an electric pump unit including a pump unit that sucks and discharges fluid, and an electric motor that drives the pump unit, wherein the electric motor is described in claims 1 to. It is constituted by the electric motor according to any one of 5 above.

  According to the configuration, in the electric pump unit including the pump unit that sucks and discharges the fluid and the electric motor that drives the pump unit, the electric motor includes the electric motor according to any one of claims 1 to 5. Therefore, the axial vibration and circumferential rotation of the stator core accompanying the rotation of the rotor are effectively suppressed, and an electric pump unit having high reliability can be obtained.

  According to a seventh aspect of the present invention, in the electric pump unit according to the sixth aspect, a circuit board for controlling the motor unit is attached to the motor case from the outside of the partition wall, and the circuit board is accommodated and sealed. A gist is that a controller housing portion is provided, and a portion where the screw is screwed to the partition wall is liquid-tightly separated from the outside by the controller housing portion.

  According to this configuration, the controller housing portion that houses and seals the circuit board makes the portion where the screw is inserted into the partition wall and the insulator liquid-tight, so that water and mud enter the electric motor from the portion. Effectively prevented.

  According to the electric motor of the present invention, axial vibration and circumferential rotation of the stator core accompanying the rotation of the rotor are effectively suppressed, and transmission loss of the driving force of the motor unit is effectively achieved, and high reliability is achieved. Is realized.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.
The electric motor 1 of the present embodiment is used for an electric pump unit 100 used as a hydraulic pump for a transmission of an automobile, for example, as shown in FIGS. 1 and 2, and includes a motor unit 10 and the motor unit. And a motor case 11 formed into a bottomed square cylindrical shape (cylindrical shape) by aluminum die casting so as to accommodate 10.

  The electric pump unit 100 further includes a pump unit 2 that sucks and discharges fluid. The pump unit 2 and the motor unit 10 are unitized so that the pump unit 2 is driven by the motor unit 10. ing.

  Here, the pump part 2 is accommodated in a pump case 20 formed in a bottomed square cylindrical shape (cylindrical shape) using aluminum die casting. The pump section 2 has an outer rotor 21 having a trochoidal tooth profile and an inner rotor 22 meshed with the outer rotor 21 so as to be rotatable. The rotation of the rotors 21 and 22 within the pump case 20 is performed. This constitutes a so-called trochoid pump that sucks and discharges fluid. Here, in the pump case 20, a cylindrical space that accommodates the outer rotor 21 and the inner rotor 22 is sealed by the pump plate 23, thereby forming a pump chamber 24. The motor case 11 and the pump case 20 are integrated with each other to form a case body 30, and the cases 11 and 20 are motor side wall portions 20 a of the pump case 20 (the bottom portion of the pump case 20). It is partitioned. In addition, a partition wall 11 a that partitions the space 10 a that houses the motor unit 10 and the outside in the axial direction (electronic component housing chamber 31) is formed by the bottom of the motor case 11.

  On the other hand, as shown in FIG. 1, the motor unit 10 includes a rotor 12, a stator core 13 disposed around the rotor 12, a coil 14 wound around the stator core 13, and the stator core 13 from the coil 14. And a resin (insulator) insulator 15 fixed to the stator core 13.

  Specifically, a ring-shaped magnet 15 a is fixed to the outer periphery of the rotor 12. And this magnet 15a is supported by the large diameter part formed in the rotor 12, and the both ends of the rotor 12 are the 1st rolling bearing 4 provided in the edge part center (bottom part) of the said pump case 20. The case body 30 is rotatably supported via a second rolling bearing 5 provided at the center (bottom) of the end of the motor case 11. A pair of insulators each made of PPS (polyphenylene sulfide) resin (insulator) from both axial ends (pump side and motor side) of the stator core 13 to insulate the stator core 13 from the coil 14 with respect to the stator core 13. 15 and 15 are fitted. The motor unit 10 is configured such that the rotor 12 drives the pump unit 2 by pivotally supporting the inner rotor 22 of the pump unit 2. In the electric motor 1 shown in FIG. 1, the stator core 13 is fixed to the inner surface 11 b of the motor case 11 with an adhesive 6. Here, as the adhesive 6, for example, an anaerobic modified acrylic resin adhesive can be used.

  In the case main body 30 shown in FIG. 1, the motor side wall 20 a partitions the pump chamber 24 and the space 10 a that houses the motor unit 10 in the motor case 11. A through hole 7 through which the rotor 12 is inserted is formed at a substantially central portion in the radial direction of the motor side wall portion 20a. An oil seal 8 is attached to the inner surface of the through-hole 7 so that oil passing through the pump chamber 24 does not enter the space 10 a that houses the motor unit 10 in the motor case 11.

  As shown in FIG. 1, the electric pump unit 100 according to the present embodiment includes a rectangular circuit for controlling the motor unit 10 from the outside of the partition wall 11 a of the motor case 11 (on the outer end surface 11 c side of the motor case 11). A substrate 9 is attached to the motor case 11. Here, the motor case 11 is formed in a bottomed rectangular tube shape as described above, and its cross-sectional shape is a quadrangle shape, so that the circuit board 9 is easily disposed on the outer end surface 11c. . The circuit board 9 is housed and sealed in a controller housing portion 9b together with electronic components 9a such as coils and capacitors on the board 9, and the controller 90 of the electric pump unit 100 is configured by these members. An electronic component housing chamber 31 is formed by a space for housing and sealing the circuit board 9 in the controller housing portion 9b. The electronic component housing chamber 31 is liquid-tightly separated from the outside, thereby ensuring waterproofness and mudproofing to the circuit board 9 and the electronic component 9a housed in the electronic component housing chamber 31. Has been. In the electric motor 1 shown in FIGS. 1 and 2, the insulator 15 on the motor side (right side in FIG. 2) is integrated with a bus bar terminal (external connection terminal of the coil 14) and a nut. The terminal portion 16 that also serves as (the female screw is cut) is in-molded (embedded). The bus bar terminal and the circuit board 9 are electrically connected by screwing a screw 17 to the terminal portion 16. With this configuration, the drive current controlled by the circuit board 9 is supplied to the coil 14 via the terminal portion 16.

  As shown in FIGS. 1 and 2, the electric motor 1 according to the present embodiment is characterized in that an insulator 15 fixed to a stator core 13 is fixed to a partition wall 11 a formed of a bottom portion of a motor case 11 using screws 18. There is to be. Specifically, as shown in FIG. 2, an insertion hole 18 a is formed in the motor-side insulator 15 along the axial direction of the electric motor 1, and a metal (copper, iron, or the like) is located in the middle of the insertion hole 18 a. The made nut 19 is in-molded (embedded) by insert molding. Then, the screw 18 is inserted into the partition wall 11a along the axial direction of the electric motor 1 from the controller accommodating portion 9b (electronic component accommodating chamber 31), and is screwed into the nut 19 embedded in the insulator 15 on the motor side. Are combined. In the electric motor 1 shown in FIG. 1, the insulator 15 is fixed to the partition wall 11 a via screws 18 and 18 at two portions 18 c and 18 c respectively located in the vicinity of the left and right side surfaces of the motor case 11. Yes. Further, the portions 18c and 18c where the screws 18 and 18 are screwed into the partition wall 11a are both liquid-tightly separated from the outside by the controller housing portion 9b.

The electric motor 1 of the present embodiment is configured as described above, and has the following operations and effects. That is,
(1) An insulator 15 (on the motor side) fixed to the stator core 13 is fixed via a screw 18 to a partition wall 11a (bottom of the motor case 11) that partitions the space for housing the motor unit 10 from the outside in the axial direction. ing. For this reason, since the stator core 13 is fixed to the motor case 11 via the insulator 15, the axial vibration and the circumferential rotation of the stator core 13 accompanying the rotation of the rotor 12 are effectively suppressed. Become.

  (2) In addition to the stator core 13 being fixed to the partition wall 11a comprising the bottom of the motor case 11 via the insulator 15 (on the motor side) and the screw 18, in addition to the inner surface 11b of the motor case 11 It is fixed via an adhesive 6. For this reason, the stator core 13 is more reliably (strongly) fixed to the motor case 11 as compared to the case where there is no such fixing by the adhesive 6, and the axial vibration of the stator core 13 accompanying the rotation of the rotor 12 Circumferential rotation is more effectively suppressed.

  (3) Since the motor case 11 is formed in a bottomed rectangular tube shape, it is easy to dispose the square circuit board 9 on the outer end surface 11c side of the motor case 11. Further, a partition wall 11 a to which the stator core 13 is fixed via an insulator 15 (on the motor side) and a screw 18 (and a nut 19) is constituted by the bottom portion of the motor case 11. For this reason, a separate member constituting the partition wall 11 a is not required, the structure is simplified, and the stator core 13 can be reliably and stably fixed to the motor case 11.

  (4) The motor-side insulator 15 is fixed to the partition wall 11a via screws 18 and 18 at two portions 18c and 18c located near the left and right side surfaces of the motor case 11 (fixed at symmetrical positions). Therefore, the rotation (circumferential direction) of the stator core 13 accompanying the rotation of the rotor 12 can be more effectively suppressed.

  (5) Since the screw 18 inserted through the partition wall 11a (bottom part of the motor case 11) is screwed into the metal nut 19 embedded in the insulator 15 on the motor side, the stator core 13 can be mounted with a simple configuration. It can be securely and stably fixed to the motor case 11.

  (6) In the electric pump unit 100 including the pump unit 2 that sucks and discharges fluid and the electric motor that drives the pump unit 2, the electric motor is configured by the electric motor 1 of the present embodiment. For this reason, the axial vibration and circumferential rotation of the stator core 13 accompanying the rotation of the rotor 12 are effectively suppressed, and an electric pump unit having high reliability can be obtained.

  (7) Since the portion 18c through which the screw 18 is inserted into the partition wall 11a and the insulator 15 is liquid-tight by the controller housing portion 9b that houses and seals the circuit board 9, the portion 18c is passed through the insertion hole 18a. Intrusion of water and mud into the electric motor 1 is effectively prevented.

The above embodiment may be modified as follows.
In the above embodiment, the motor-side insulator 15 is fixed to the partition wall 11a with the screws 18 and 18 at the two portions 18c and 18c located near the left and right side surfaces of the motor case 11, respectively. However, the fixing part of the insulator 15 with respect to the partition wall 11a is not limited to the two parts 18c and 18c, and is, for example, a point-symmetrical position about the central axis 12a of the rotor 12 (see FIGS. 1 and 2). Three or more locations may be provided.
In the above embodiment, the partition wall 11 a to which the insulator 15 is fixed is configured at the bottom of the motor case 11. However, the present invention is not limited to this, and the partition wall 11 a may be anything that is integrated with the motor case 11 and fixed to the motor case 11. Therefore, for example, the partition wall 11a may be provided independently of the motor case 11, and may be fixed to the motor case 11 using fixing means such as screws.
In the above embodiment, the stator core 13 is fixed to the inner surface of the motor case 11 via the adhesive 6, but the fixing with the adhesive 6 is not necessarily performed. Therefore, only by the insulator 15 being fixed to the partition wall 11a using the screw 18, the effect of suppressing the axial vibration and circumferential rotation of the stator core 13 accompanying the rotation of the rotor 12 can be obtained.

The axial direction end view of the electric pump unit which concerns on embodiment of this invention. Sectional drawing which shows the structure of the axial cross section of the electric pump unit along the AA line in FIG. Sectional drawing which shows the structure of the axial direction of the electric pump unit which concerns on a prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electric motor, 10 ... Motor part, 11 ... Motor case, 11a ... Partition wall, 13 ... Stator core, 14 ... Coil, 15 ... Insulator, 18 ... Screw.

Claims (7)

A motor unit having a rotor and a stator core disposed around the rotor; a coil wound around the stator core; and an insulator fixed to the stator core to insulate the stator core from the coil;
A cylindrical motor case that houses the motor unit,
In the electric motor, the motor case has a stator wall integrally fixed to an inner surface of the motor case, and a partition wall that integrally partitions the space for housing the motor portion and the outside in the axial direction.
The electric motor, wherein the insulator is fixed to the partition wall using a screw. The electric motor according to claim 1,
An electric motor in which the stator core is fixed to an inner surface of the motor case via an adhesive. In the electric motor according to claim 1 or 2,
An electric motor in which the motor case is formed in a bottomed rectangular tube shape and the partition wall is formed by a bottom portion of the motor case. In the electric motor according to any one of claims 1 to 3,
An electric motor in which the insulator is fixed to the partition wall using screws at two locations where the insulator is located near the left and right side surfaces of the motor case. The electric motor according to claim 4,
An electric motor in which the screw is screwed into a nut embedded in the insulator. An electric pump unit comprising a pump unit that sucks and discharges fluid, and an electric motor that drives the pump unit,
An electric pump unit comprising the electric motor according to any one of claims 1 to 5. In the electric pump unit according to claim 6,
A circuit board for controlling the motor part is attached to the motor case from the outside of the partition wall, and a controller housing part for housing and sealing the circuit board is provided, and the screw is screwed into the partition wall. The electric pump unit is characterized in that the portion of the pump is separated from the outside by the controller housing portion in a liquid-tight manner.

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