JP2019203389A - Motor pump - Google Patents

Abstract

To increase the heat dissipation property of a motor pump.SOLUTION: A motor pump 1 includes a pump part 2, a motor part 4 for driving the pump part 2, and a control part 5 for controlling the motor part 4, the pump part 2 including a pump housing 8, the motor part 4 including a motor housing 22, the pump housing 8 and the motor housing 22 being integrally constructed of metal.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electric pump used as an oil pump, for example.

  As this type of electric pump, Patent Document 1 discloses a pump that includes a pump unit, a motor unit that drives the pump unit, and a control unit that controls the motor unit.

  The pump unit includes a metal pump housing that houses the inner rotor and the outer rotor. The pump housing includes a main housing and a sub-housing fixed to the main housing. The motor unit includes a resin motor housing that houses a motor rotor and a stator. The control unit includes a driver chamber that houses a control board (driver). The driver chamber includes a driver case configured integrally with the motor housing and a cover fixed to the driver case.

  The main housing of the pump housing includes a columnar bulging portion that protrudes toward the motor portion. The motor housing includes a cylindrical inner surface-like fitting surface. The pump housing and the motor housing are connected by fitting the bulging portion to the fitting surface (see paragraphs 0022 and 0025 of FIG. 1 and FIG. 1).

JP-A-2018-62931

  In the conventional electric pump, the pump housing and the motor housing are configured as separate members using different materials (metal and resin). In particular, since the motor housing is made of a resin having low thermal conductivity, sufficient heat dissipation cannot be ensured when a large current is passed through the motor portion in a small electric pump.

  This invention is made | formed in view of said situation, and it aims at providing the electric pump which can improve heat dissipation.

  The present invention is for solving the above problems, and in an electric pump including a pump unit, a motor unit that drives the pump unit, and a control unit that controls the motor unit, the pump unit includes: A pump housing is provided, and the motor unit includes a motor housing, and the pump housing and the motor housing are integrally formed of metal.

  According to this configuration, the heat generated in the motor unit can be conducted from the motor housing to the pump housing by integrally configuring the pump housing and the motor housing with metal. Thereby, the heat dissipation of an electric pump can be improved as much as possible.

  The control unit may include a control board and a case that accommodates the control board, and the case may include a resin case main body and a resin case cover that is fixed to the case main body. By making the case of the control unit made of resin, it is possible to prevent the heat generated in the motor unit from being conducted to the control unit. In addition, when the case cover is made of resin, the degree of freedom in design can be increased when a coupler or the like is formed on the outer surface side of the case cover.

  The case cover may include a heat sink that is insert-molded to the case cover. Thereby, the heat generated from the control board can be released by the heat sink. Moreover, the assembly | attachment property of the control part with respect to an electric pump improves by insert-molding a heat sink to a case cover.

  The case may include a welding portion that welds the case body and the case cover. Thereby, a case cover can be firmly fixed with respect to a case main body, without using a fixing member.

  In the electric pump according to the present invention, the pump portion can be used as an oil pump.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to improve the heat dissipation of an electric pump.

It is sectional drawing of the electric pump in 1st embodiment. It is a disassembled perspective view of the control part in an electric pump. It is sectional drawing of the electric pump in 2nd embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. 1 and 2 show a first embodiment of an electric pump according to the present invention. In the present embodiment, an oil pump used for lubricating an engine oil of an automobile or supplying hydraulic pressure to a transmission is illustrated as an electric pump, but the application of the present invention is not limited to this.

  As shown in FIG. 1, the electric pump 1 includes a pump unit 2, a motor unit 4 having a rotating shaft 3 that drives the pump unit 2, and a control unit 5 that controls the motor unit 4.

  The pump unit 2 is configured by a trochoid pump, but is not limited thereto, and may be configured by a vane pump or other pumps. The pump unit 2 includes an inner rotor 6, an outer rotor 7, a pump housing 8 that houses the inner rotor 6 and the outer rotor 7, and a pump cover 9 that is fixed to the pump housing 8.

  The inner rotor 6 has a through hole 10 through which the rotary shaft 3 is inserted. The through hole 10 of the inner rotor 6 and the rotary shaft 3 are connected by means such as spline fitting. The inner rotor 6 and the outer rotor 7 are accommodated in a rotor chamber 11 formed by a pump housing 8 and a pump cover 9.

  The pump housing 8 is configured in a predetermined shape with a metal such as an aluminum alloy. The pump housing 8 includes a recess 12 constituting a part of the rotor chamber 11, a hole (hereinafter referred to as “insertion hole”) 13 for inserting the rotary shaft 3, and a pump cover 9 for fixing the pump cover 9 to the pump housing 8. And a screw hole 14. In addition, the pump housing 8 includes a suction port and a discharge port (not shown) for circulating hydraulic oil (oil).

  The recess 12 has a size and depth that can accommodate the inner rotor 6 and the outer rotor 7. The insertion hole 13 is configured as a circular hole through which the rotary shaft 3 can be inserted. The screw hole 14 penetrates a part of the pump housing 8 in the axial direction (direction parallel to the rotation shaft 3).

  The pump cover 9 is formed in a plate shape from a metal such as an aluminum alloy. The pump cover 9 includes a recess 15 that accommodates a part of the rotary shaft 3, a groove portion 17 that accommodates the seal member 16, and a plurality of through holes 18.

  The recess 15 has a circular inner peripheral surface having an inner diameter slightly larger than the outer diameter of the rotating shaft 3. The concave portion 15 accommodates a part of the rotating shaft 3 to restrict the rotating shaft 3 from being inclined. Not limited to this configuration, the recess 15 may be provided with a bearing that supports the rotating shaft 3.

  The groove portion 17 is formed in an annular shape so as to surround the recess 15. An O-ring is accommodated in the groove portion 17 as the seal member 16.

  The through hole 18 is for inserting a fixing member 19 such as a bolt for fixing the pump cover 9 to the pump housing 8. The pump cover 9 is fixed to the pump housing 8 by matching the through hole 18 with the screw hole 14 of the pump housing 8 and screwing the fixing member 19 into the screw hole 14 through the through hole 18.

  In addition to the rotating shaft 3, the motor unit 4 includes a motor rotor 20 configured integrally with the rotating shaft 3, a stator 21, and a motor housing 22 that houses the motor rotor 20 and the stator 21.

  The rotating shaft 3 is configured as a stepped shaft. One end (hereinafter referred to as “first end”) 3 a of the rotating shaft 3 is accommodated in the recess 15 of the pump cover 9 related to the pump unit 2. The other end (hereinafter referred to as “second end”) 3 b of the rotating shaft 3 is supported by a part of the control unit 5.

  The motor rotor 20 includes a rotor core 23 provided between the first end 3 a and the second end 3 b of the rotating shaft 3, and a permanent magnet 24 attached to the outer periphery of the rotor core 23.

  The stator 21 is fixed to the inner surface of the motor housing 22. The stator 21 includes a stator core 25, an insulating bobbin 26 attached to the stator core 25, and a coil 27 wound around the bobbin 26.

  The motor housing 22 is made of a metal such as an aluminum alloy. The motor housing 22 is formed integrally with the pump housing 8 using the same metal as the pump housing 8. That is, the pump housing 8 and the motor housing 22 are a molded product (die cast molded product) integrated by casting such as die casting.

  With the above configuration, the portion (hereinafter referred to as “intermediate portion”) 28 between the pump housing 8 and the motor housing 22 has no seam between the pump housing 8 and the motor housing 22, and there are also surfaces that contact each other. do not do. The intermediate portion 28 is provided with a seal member 29 (oil seal) that prevents hydraulic oil from entering the motor portion 4 in the pump portion 2. The seal member 29 is in contact with the outer peripheral surface in the middle part of the rotary shaft 3.

  An accommodating portion 30 for the seal member 29 is formed in the intermediate portion 28. The accommodating portion 30 has a support surface 31 that contacts the seal member 29. The support surface 31 is formed so as to be adjacent to the insertion hole 13 of the pump housing 8 in the axial direction. The support surface 31 is configured to have a circular shape when viewed from the front. The diameter of the support surface 31 is larger than the diameter of the insertion hole 13 of the pump housing 8.

  The motor housing 22 is provided with a bearing 32 that supports the rotating shaft 3. Although the bearing 32 is comprised by a ball bearing, it is not limited to this, A needle bearing and other various bearings are employable. The bearing 32 includes an outer ring 33 attached to the motor housing 22, an inner ring 34 attached to the rotary shaft 3, and balls 35 as rolling elements disposed between the outer ring 33 and the inner ring 34.

  The motor housing 22 has a support surface 36 that contacts the outer ring 33 of the bearing 32. The support surface 36 is formed so as to be adjacent to the support surface 31 formed in the accommodating portion 30 of the intermediate portion 28 in the axial direction. The support surface 36 is configured in a circular shape when viewed from the front. The diameter of the support surface 36 is larger than the diameter of the support surface 31 of the intermediate portion 28.

  The control unit 5 is connected to the end of the motor housing 22. The control unit 5 includes a control board 37 that controls the motor unit 4 and a case 38 that houses the control board 37.

  The control board 37 mounts an inverter circuit and a power control circuit composed of various electronic components. The control board 37 is connected to the stator 21 (coil 27) of the motor unit 4 via the bus bar 39.

  The case 38 includes a case main body 40 connected to the motor housing 22 and a case cover 41 fixed to the case main body 40. The case main body 40 and the case cover 41 are made of resin (for example, a glass fiber blended with polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), nylon (PA66, etc.)), for example, to a predetermined shape by injection molding. Composed.

  The case main body 40 includes a support portion 42 that supports the second end portion 3 b of the rotating shaft 3, and a protruding portion 43 that fits into the motor housing 22.

  The support portion 42 includes a cylindrical portion 44 that is integrally formed with the case main body 40 and a bearing 45 that is disposed on the cylindrical portion 44. The cylindrical portion 44 is configured in a cylindrical shape and protrudes from the case main body 40 in the axial direction. A ring body 46 that supports the bearing 45 is disposed inside the cylindrical portion 44. The ring body 46 is made of metal (for example, cold rolled steel plate, stainless steel, carbon steel), and is fixed to the tubular portion 44 by insert molding.

  The bearing 45 is constituted by a needle bearing, but may be constituted by other various bearings. The bearing 45 includes needle rollers 47 serving as rolling elements and a shell-shaped outer ring 48 disposed inside the ring body 46. A thrust washer 49 is provided between the bearing 45 and the motor rotor 20 of the rotating shaft 3.

  The protrusion 43 is fitted from the end of the motor housing 22 to the inside of the motor housing 22. On the outer surface of the protrusion 43, a groove 51 for accommodating the seal member 50 is formed. An O-ring is attached to the groove 51 as the seal member 50.

  The case cover 41 is fixed to the case main body 40 via a fixing member 52 such as a bolt. The case cover 41 includes a coupler 53 formed on the outer surface side thereof, and a heat sink 54 fixed to the case cover 41.

  The coupler 53 includes a plurality of connection terminals 55 for power supply connection and electrical signals, and a cylindrical cover portion 56 that covers the connection terminals 55. The connection terminal 55 and the cover portion 56 protrude outward in the axial direction from the outer surface of the case cover 41.

  The heat sink 54 is made of a metal such as an aluminum alloy. The heat sink 54 is integrated with the case cover 41 by insert molding. The heat sink 54 includes a plate-like base 57 and a plurality of fins 58 protruding from the base 57. The base 57 is fixed to the case cover 41 and is in contact with the control board 37 through the heat dissipation sheet 59. The heat radiating sheet 59 is made of a material having good thermal conductivity such as silicone rubber. The fin 58 protrudes (exposes) outside the case cover 41.

  According to the electric pump 1 according to the present embodiment described above, since the pump housing 8 and the motor housing 22 are integrally formed of metal (for example, aluminum alloy), the heat generated in the motor unit 4 is generated by the motor housing 22. The heat dissipation can be enhanced by conducting the heat to the pump housing 8. Furthermore, the electric pump 1 can further improve its heat dissipation due to the cooling effect of the pump housing 8 by the hydraulic oil flowing through the pump portion 2.

  Further, by integrally forming the pump housing 8 and the motor housing 22 with metal, it is not necessary to connect them with a fastening member or seal them with a sealing member, and the electric pump 1 can be reduced in size and weight. it can.

  Moreover, the case 38 of the control unit 5 is made of resin, so that heat generated in the motor unit 4 can be prevented from being conducted to the control unit 5. Furthermore, the case cover 41 is made of resin, so that the degree of freedom in design when the coupler 53 is formed on the outer surface side of the case cover 41 can be increased.

  FIG. 3 shows a second embodiment of the electric pump. In the present embodiment, the configuration of the case 38 in the control unit 5 is different from that in the first embodiment. The case 38 of the control unit 5 according to the first embodiment has a configuration in which the case cover 41 is fixed to the case main body 40 by the fixing member 52, but the case 38 according to the present embodiment has the control unit 5 as the motor unit 4. After the assembly, the case cover 41 is welded to the case body 40.

  Thereby, the welding part 60 which connects both integrally is formed between the case main body 40 and the case cover 41. In the present embodiment, since the case cover 41 can be fixed to the case body 40 without using the fixing member 52 in the first embodiment, the manufacturing efficiency of the electric pump 1 is improved, and the electric pump 1 is reduced in weight and size. Can be realized. Other configurations in the present embodiment are the same as those in the first embodiment. In this embodiment, components common to the first embodiment are denoted by common reference numerals.

  In addition, this invention is not limited to the structure of the said embodiment, Moreover, it is not limited to an above-described effect. The present invention can be variously modified without departing from the gist of the present invention.

  In the above embodiment, an example in which the heat sink 54 is insert-molded in the case cover 41 has been shown. You may attach with respect to the case cover 41 at the time of attachment work.

  In the second embodiment, the case cover 41 of the control unit 5 is welded to the case body 40. However, the present invention is not limited thereto, and the case cover 41 is fixed to the case body 40 with an adhesive. Also good.

DESCRIPTION OF SYMBOLS 1 Electric pump 2 Pump part 4 Motor part 5 Control part 8 Pump housing 22 Motor housing 37 Control board 38 Case 40 Case main body 41 Case cover 54 Heat sink 60 Welding part

Claims (5)

In an electric pump comprising a pump unit, a motor unit that drives the pump unit, and a control unit that controls the motor unit,
The pump part includes a pump housing,
The motor unit includes a motor housing,
The electric pump characterized in that the pump housing and the motor housing are integrally formed of metal. The control unit includes a control board and a case that houses the control board,
The electric pump according to claim 1, wherein the case includes a resin case main body and a resin case cover fixed to the case main body.   The electric pump according to claim 2, wherein the case cover includes a heat sink formed by insert molding on the case cover.   The electric pump according to claim 2, wherein the case includes a welding portion that welds the case main body and the case cover. The electric pump according to claim 1, wherein the pump unit is an oil pump.

Images