JP5644356B2 - Electric pump unit - Google Patents

Description

  The present invention relates to an electric pump unit used as a hydraulic pump for supplying hydraulic pressure to a transmission (transmission) of an automobile, for example.

  Oil pressure is supplied to the vehicle's transmission by a hydraulic pump, but for vehicles that perform so-called idle stop (idling stop) that stops the engine when the vehicle is stopped from the standpoint of energy saving, etc., ensure that the hydraulic pressure is supplied to the transmission even during idle stop. In order to do so, an electric hydraulic pump is used.

  Since an electric hydraulic pump for an automobile transmission is mounted in a limited space of a vehicle body, it is required to be compact, and to be light and reduce costs. In order to meet such demands, an electric pump unit in which one end of a motor housing incorporating a pump driving electric motor and its controller is connected to a pump housing constituting the pump, and the other end opening of the motor housing is sealed with a lid Has been proposed (see, for example, Patent Document 1).

  In such a conventional electric pump unit, the motor housing and the lid are made of metal such as an aluminum alloy, and the lid is fixed to the motor housing by screws. A controller board is fixed to the end surface of the motor opposite to the pump housing, and a plurality of electrical components (electrical components and electronic components) such as capacitors and FETs constituting the controller are attached to the substrate.

JP 2010-116914 A

  The electric pump unit for an automobile is disposed in the engine room of the automobile, and the temperature of the component rises due to the heat generated by the stator coil of the motor and the self-heating of the component on the board of the controller. Furthermore, in order to ensure water resistance, it is necessary to securely seal the motor housing.

  In recent years, in order to reduce the weight of the electric pump unit and reduce the cost, it has been proposed that the motor housing and the lid be made of a synthetic resin. When the motor housing and the lid are made of synthetic resin, it is conceivable to employ ultrasonic welding or spin welding instead of conventional screwing, but there is a problem that the sealing performance is easily influenced by processing conditions.

  An object of the present invention is to provide an electric pump unit that solves the above-described problems, achieves weight reduction and compactness, and has a high heat dissipation effect and sealing effect.

In the electric pump unit according to the present invention, one end of a motor housing incorporating a pump drive electric motor is connected to a pump housing of a pump that sucks and discharges oil, and the other end opening of the motor housing is formed separately from the motor housing. In the electric pump unit hermetically sealed with the lid, the lid is made of metal, extends in the axial direction and enters the inside of the other end opening of the motor housing, and projects from the cylindrical portion to the outside in the radial direction. A rubber seal member formed integrally on the outer peripheral surface of the cylindrical portion of the lid and the surface of the flange on the motor housing side, and the seal member of the cylindrical portion of the lid is a motor. The lid is fixed to the motor housing by being press-fitted into the inner periphery of the other end of the housing, and the seal member of the lid flange is pressed against the other end surface of the motor housing. And it is characterized in that it is allowed.

  In this electric pump unit, the lid can be easily and reliably fixed to the motor housing simply by press-fitting the seal member of the cylindrical portion of the lid into the inner periphery of the other end of the motor housing. The seal member is pressed against the inner periphery of the motor housing, and the seal member of the lid flange is pressed against the end surface of the motor housing, thereby achieving high sealing performance.

  Since the lid is made of metal, high heat dissipation is obtained. For this reason, even if the motor housing is made of synthetic resin, the overall heat dissipation is high. The metal constituting the lid is preferably a highly corrosion resistant material such as stainless steel.

  When the motor housing is made of synthetic resin, the motor stator can be provided integrally with the motor housing. The motor stator is obtained by winding a coil around a synthetic resin insulator incorporated in a core. The motor housing and the insulator can be integrally molded with a synthetic resin in a form incorporating a core. The motor stator is integrally provided on the motor housing by winding a coil around the insulator portion thus integrally molded. If the motor housing and the insulator are integrally molded, these assembling operations become unnecessary, and the dimensional management of the motor housing becomes easy.

  For example, an electric motor controller is also provided in the motor housing. When the motor housing incorporating the controller is made of synthetic resin and molded integrally with the insulator, the connector can be molded integrally with the motor housing. At this time, the pins of the connector and the conductive member for connecting the pins to the controller can also be integrally molded in a form embedded in the connector portion or the like. Then, the assembly work of the connector with respect to the motor housing is unnecessary, and the connection work of pins and conductive members is also unnecessary. Further, the motor controller board is fixed to one end of the insulator, and one end of the connector conductive member that is electrically connected to the connector pin and protrudes from the insulator portion is electrically connected to the board. The coil conductive member is embedded in the insulator portion, one end of the coil conductive member is exposed at the end of the insulator and is electrically connected to the substrate, and the other end is connected to the coil. Can do. Then, the coil wound around the insulator is connected to the coil conductive member, and the coil and the substrate are electrically connected only by fixing the substrate to one end of the insulator, so that the wiring work is easy.

  In the present invention, for example, an annular protrusion protruding in the axial direction is integrally formed at a portion radially inward from the outer periphery of the other end surface of the motor housing, and an annular lip protruding in the axial direction is formed on the seal member of the lid flange. The annular projection of the motor housing bites into the inner part of the lid of the lid flange in the radial direction from the annular lip, and the annular lip is pressed against the end face of the motor housing radially outside the annular projection. ing.

  In this case, the sealing performance is further enhanced by the annular protrusion of the motor housing biting into the seal member and the annular lip of the seal member being pressed against the end surface of the motor housing.

  According to the electric motor unit of the present invention, as described above, it is possible to reduce the weight and the size, and to enhance the heat dissipation effect and the sealing effect.

FIG. 1 is a longitudinal sectional view of an electric pump unit showing an embodiment of the present invention. FIG. 2 is a perspective view in which a part of the resin molded body of FIG. 1 is removed. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is an enlarged longitudinal sectional view showing a part of FIG. FIG. 5 is an enlarged longitudinal sectional view showing a part of the lid.

  Hereinafter, an embodiment in which the present invention is applied to an electric pump unit for an automobile transmission will be described with reference to the drawings.

  FIG. 1 is a longitudinal sectional view of an electric pump unit, and FIGS. 2 to 5 are drawings showing the main part thereof. In the following description, the left side of FIG. 1 is the front and the right side is the rear.

  The electric pump unit is a unit housing (1) in which a pump (2) and a pump driving electric motor (3) are integrated. The controller (4) of the motor (3) is also incorporated in the housing (1). In this example, the pump (2) is an internal gear pump, and the motor (3) is a sensorless control DC brushless motor having a three-phase winding.

  The unit housing (1) includes a pump housing (5) constituting the pump (2), a motor housing (6) incorporating a motor (3) and a controller (4), and a lid (7).

  The pump housing (5) includes a front half (pump plate) (8) and a rear half (pump housing) (9). The rear half (9) has a thick cylindrical shape extending in a direction perpendicular to the front-rear direction, and a pump chamber (10) having an open front is formed at the center thereof. The front half (8) is fixed to the front face of the rear half (9) via an O-ring (11), and the front face of the pump chamber (10) is closed. An outer gear (12) constituting the pump (2) is rotatably accommodated in the pump chamber (10), and an inner gear (13) that meshes with the inner gear (12) is disposed inside the outer gear (12). Although not shown, the front half (8) is provided with an oil suction port and an oil discharge port.

  The motor housing (6) has a cylindrical shape, and its front end is fixed to the rear surface of the rear half (9) via a seal (14). The front and rear halves (8), (9) and the motor housing (6) are formed in a plurality of connecting portions (8a), (9a) and (6a) integrally formed so as to protrude radially outward from the outer periphery thereof. These are fixed to each other by bolts (15). The rear end opening of the motor housing (6) is sealed with a lid (7).

  A cylindrical portion (9b) protruding into the motor housing (6) is integrally formed at the center of the rear end surface of the rear half (9), and a bearing device (16 ), The pump drive motor shaft (17) extending in the front-rear direction is cantilevered. In this example, the bearing device (16) is composed of two ball bearings (18) which are adjacent to the front and rear, and the inner ring (18a) of each bearing (18) is fixed to the motor shaft (17). The outer ring (18b) is fixed to the cylindrical portion (9b). The front part of the motor shaft (17) penetrates the hole (19) formed in the rear wall of the rear half (9) and enters the pump chamber (10), and the front end thereof is the inner gear (13 ). An oil seal (20) is provided between a portion of the cylindrical portion (9b) in front of the bearing device (16) and the motor shaft (17).

  A motor rotor (21) constituting the motor (3) is fixed to a rear end portion of the motor shaft (17) protruding rearward from the cylindrical portion (9b). The rotor (21) extends from the rear end of the motor shaft (17) in the radial direction and surrounds the outer periphery of the bearing device (16) on the outer periphery of a cylindrical rotor body (22). ) Are provided in a fixed shape, and segment-shaped permanent magnets (24) are held at a plurality of locations that equally divide the holding member (23) in the circumferential direction. The axial position of the center of gravity of the rotating part including the motor shaft (17), the rotor (21), and the inner gear (13) of the pump (2) is within the axial range of the bearing device (16). In this example, the axial position of the center of gravity is between two ball bearings (18) constituting the bearing device (16).

  A motor stator (25) constituting the motor (3) is fixedly provided on the inner periphery of the motor housing (6) facing the rotor (21). In the stator (25), an insulator (synthetic resin insulator) (27) is incorporated in a core (26) made of laminated steel sheets, and a stator coil (28) is wound around the insulator (27). .

  A board (29) of the controller (4) is fixed to the rear end of the insulator (27) with screws (30), and a component (31) constituting the controller (4) is attached to the board (29). The component is disposed at a predetermined position on at least one of the front surface and the rear surface of the substrate (29). In the drawing, one component (31) attached to the front surface of the substrate (29) is shown.

  The motor housing (6) is provided with a connector (33) having a plurality (four in this example) of pins (32).

  In the electric pump unit described above, the motor housing (6) and the insulator (27) are integrally formed of synthetic resin in a form incorporating the core (26). In this example, the connector (33) is also formed integrally with the motor housing (6) and the insulator (27) in a form incorporating the pin (32).

  2 and 3 show an example of a resin molded body (34) in which the motor housing (6) and the insulator (27) are integrated.

  As shown in detail in FIGS. 2 and 3, the core (26) is integrally formed with pole portions (26a) protruding radially inward at six locations that equally divide the inner periphery of the annular body in the circumferential direction. Is. The tip of each pole portion (26a) extends on both sides in the circumferential direction, and its inner peripheral surface forms one cylindrical surface. The insulator (27) is formed integrally with the motor housing (6) so as to cover the annular portion of the core (25) and to cover the portion excluding the inner peripheral surface of the pole portion (26a). Then, after the molded body (34) is molded, the coil (28) is wound around the insulator (27) of each pole portion (26a).

  The rear protrusions (27a) are integrally formed at six locations that equally divide the rear end surface of the insulator (27) in the circumferential direction, and the rear end surfaces of these protrusions (27a) form one flat surface. The mounting surface of the substrate (29). A female screw (35) for mounting the substrate is formed on the rear end face of each protrusion (27a).

  Part of the three first bus bars (36) constituting the coil conductive member is embedded in the insulator (27) of the molded body (34). One end (coil side end) (36a) of each bus bar (36) protrudes rearward from the rear surface of the insulator (27) which is not the protrusion (27a), and the other end (substrate side end) (36b) protrudes. The part (27a) is exposed around the female screw (35) on the rear end surface. Although not shown in detail, three second bus bars (37) are embedded in the insulator (27). One end portions of these bus bars (37) are electrically connected to each other inside the insulator (27), and the other end portion (coil side end portion) (37a) is a rear surface of the insulator (27) which is not a protruding portion (27a). Protrudes backward from

  A needle-like conductive member for connector (38) is electrically connected to each pin (32) of the connector (33). These conductive members (38) protrude rearward from the rear end face of one protrusion (27a) of the insulator (27).

  One end portion of the three-phase coil (28) wound around the insulator (27) is connected to the coil side end portion (37a) of the corresponding second bus bar (37) by TIG welding. One end portions of the phase coil (28) are connected to each other. Further, the other end portions of the three-phase coils (28) are respectively connected to the coil side end portions (36a) of the corresponding first bus bars (36) by TIG welding.

  The substrate (29) is pressed against the rear end surface of the protrusion (27a) of the insulator (27), and is fixed to the insulator (27) by a screw (30) screwed to the female screw (35). Thereby, the board | substrate side edge part (36b) of three 1st bus-bars (36) is connected to the predetermined part of the circuit of a board | substrate (29), As a result, a three-phase coil (28) is a circuit of a board | substrate (29). Connected to a predetermined portion of the.

  When the board (29) is fixed to the protrusion (27a) of the insulator (27) as described above, the connector conductive member (38) fits into a hole (not shown) formed in the board (29). It has become. Then, in this state, the conductive member (38) is soldered to the substrate (29), whereby the pin (32) of the connector (33) is connected to a predetermined part of the circuit of the substrate (29).

  The lid (7) is provided with a rubber seal member (39) for sealing the rear end opening of the motor housing (6).

  4 is an enlarged longitudinal sectional view showing a portion of the lid (7) and the seal member (39) fixed to the motor housing (6), and FIG. 5 is a view of the lid (7) before being attached to the motor housing (6). FIG. 6 is an enlarged longitudinal sectional view showing a portion of a seal member (39). In FIG. 5, the outer diameter of the longitudinal section of the rear end portion of the motor housing (6) is indicated by a chain line.

  As shown in detail in FIGS. 4 and 5, the lid (7) has a cylindrical portion (7a) extending forward in the axial direction and a flange portion (7b) projecting radially outward from the cylindrical portion (7a). It is integrally formed.

  The lid (7) is made of metal, preferably metal having corrosion resistance. In this example, the lid (7) is made of JIS SUS304, which is stainless steel, and is molded by pressing. More specifically, the outer peripheral portion of the disk is folded and overlapped to form a double collar portion (7b), and the cylindrical portion (7a) is formed on the inner circumference of the folded portion of the collar portion (7b). Is formed. The outer diameter of the cylindrical portion (7a) is smaller than the inner diameter of the rear end portion of the motor housing (6), and the outer diameter of the flange portion (7b) is substantially equal to the outer diameter of the rear end portion of the motor housing (6).

  The seal member (39) is made of, for example, H-NBR (hydrogenated acrylonitrile butadiene rubber), and covers the cylindrical portion (7a) outer peripheral surface of the lid (7) and the front surface of the flange portion (7b). It is molded integrally with the lid (7) by vulcanization molding. The sealing member (39) includes a cylindrical portion (39a) formed in the cylindrical portion (7a) and a flange-shaped portion (39b) formed in the flange portion (7b). An annular lip (39c) protruding toward the front side in the axial direction is integrally formed at a portion near the outer periphery. The outer diameter of the cylindrical portion (39a) is slightly larger than the inner diameter of the rear end portion of the motor housing (6).

  An annular projection (40) protruding rearward in the axial direction is formed integrally with a portion on the radially inner side near the outer periphery of the rear end surface (6b) of the motor housing (6), in this example, a portion closer to the inner periphery. .

  The cylindrical portion (7a) of the lid (7) is put inside the rear end opening of the motor housing (6), and the cylindrical portion (39a) of the seal member (39) is press-fitted into the opening, whereby the lid ( 7) is fixed to the motor housing (6). The protrusion (40) of the motor housing (6) bites into the flanged portion (39b) radially inward from the lip (39c) of the seal member (39), and the lip (39c) is the rear end surface of the motor housing (6). It is in pressure contact with (6b).

  In the electric pump unit described above, the lid (7) is simply press-fitted into the inner periphery of the rear end of the motor housing (6) with the cylindrical portion (39a) of the seal member (39) formed integrally with the lid (7). Can be easily and reliably fixed to the motor housing (6). The cylindrical portion (39a) of the seal member (39) is in pressure contact with the inner periphery of the motor housing (6), and the annular protrusion (40) of the motor housing (6) is a bowl-like shape of the seal member (39). High sealing performance is obtained by biting into the part (39b) and the annular lip (39c) of the seal member (39) being pressed against the rear end surface (6b) of the motor housing (6). Further, the lip (39c) prevents foreign matter from entering.

  Since the lid (7) is made of metal, high heat dissipation is obtained. For this reason, even if the motor housing (6) is made of synthetic resin, the overall heat dissipation is high. For this reason, as described above, the motor housing (6) and the insulator (27) can be integrally molded. Furthermore, there is little risk of damage even if a stepping stone hits the lid (7).

  In the electric pump unit described above, the motor housing (6) and the insulator (27) are integrally formed, so that these assembly operations are unnecessary, and the size control of the motor housing (6) is easy.

  The connector (33) is also molded integrally with the motor housing (6), and the pin (32) of the connector (33) and the conductive member (38) for connecting it to the board (29) are also connected to the connector (33) and the insulator ( 27) Since it is integrally molded in the form embedded in the part, connector assembly work and wiring work are unnecessary. Further, the board (29) is fixed to the protruding portion (27a) of the insulator (27), and the conductive member (38) is simply soldered to the board (29). It can be easily connected to the circuit of (29).

  Simply connect the coil (28) wound around the insulator (27) to the bus bar (36) (37), and fix the substrate (29) to the protrusion (27a) of the insulator (27). Can be easily connected to the circuit of the substrate (29).

  The overall configuration of the electric pump unit and the configuration of each unit are not limited to those of the above-described embodiment, and can be changed as appropriate.

  Moreover, this invention is applicable also to electric pump units other than the electric pump unit for motor vehicles.

(2) Pump
(3) Electric motor
(5) Pump housing
(6) Motor housing
(6b) Rear end face
(7) Lid
(7a) Cylindrical part
(7b) Buttocks
(39) Seal member
(39a) Cylindrical part
(39b) Spider
(39c) Annular lip
(40) Annular projection

Claims (2)

One end of a motor housing containing a pump drive electric motor is connected to the pump housing of a pump that sucks and discharges oil, and the other end opening of the motor housing is sealed with a lid made separately from the motor housing. In the electric pump unit,
Lid, perforated made of metal, a cylindrical portion that enters inside the other open end of the motor housing extends in the axial direction and a flange portion facing the other end surface of the motor housing protrudes radially outward from the cylindrical portion A rubber sealing member is integrally formed on the outer peripheral surface of the cylindrical portion of the lid and the surface of the flange on the motor housing side, and the sealing member of the cylindrical portion of the lid is press-fitted into the inner periphery of the other end of the motor housing, Is fixed to the motor housing, and a sealing member of the lid flange is pressed against the other end surface of the motor housing.   An annular protrusion protruding in the axial direction is integrally formed at a portion radially inward from the outer periphery of the other end surface of the motor housing, and an annular lip protruding in the axial direction is integrally formed on the seal member of the lid portion of the lid. The annular protrusion of the motor housing bites into the radially inner portion of the annular lip of the sealing member of the lid flange, and the annular lip is pressed against the end face of the motor housing radially outward from the annular protrusion. The electric pump unit according to claim 1.

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