JP5703862B2 - Electric motor unit and electric pump unit - Google Patents

Description

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

  Hydraulic pressure is supplied to the vehicle's transmission by a hydraulic pump. However, in order to save energy, the vehicle is stopped when the vehicle is stopped, so-called idle stop (idling stop) is secured. 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 a demand, an electric pump unit in which a pump, an electric motor for driving a pump, and a controller for the electric motor are incorporated in a common unit housing has been proposed (for example, see Patent Document 1).

  In such a conventional electric pump unit, a motor housing is connected to a pump body constituting the pump, and an electric motor and a controller are built in a sealed motor chamber formed in the motor housing. The electric motor includes a stator fixed to the motor housing and a rotor disposed inside the stator. In the stator, an insulator is incorporated in a core, and a coil is wound around the insulator. The electric motor is disposed on the pump body side in the motor chamber, and a controller board is fixed to an end surface of the electric motor opposite to the pump body, for example, an end surface of the insulator. A plurality of electrical components (electrical components and electronic components) such as capacitors and FETs constituting the controller are attached to the substrate.

JP 2008-215088 A

  The electric pump unit for an automobile is disposed in an engine room of the automobile, and the temperature of the stator rises due to the heat generated by the stator coil of the electric motor, and the temperature of the controller components also rises. In particular, the temperature of the component that receives the radiant heat from the coil rises and may exceed the limit temperature.

  An object of the present invention is to provide an electric motor unit that can solve the above-described problems and prevent the temperature rise of the components of the controller.

  Another object of the present invention is to provide an electric pump unit capable of reducing the weight and the size of the controller and preventing the temperature rise of the components of the controller.

In the electric motor unit according to the present invention, an electric motor and a controller for controlling the electric motor are accommodated in a motor housing, the electric motor is fixed to the motor housing, and a rotor disposed inside the stator. The synthetic motor permanent magnet holding member in which the rotor is provided with a shielding wall that blocks between the stator and the controller component, and the rotor is fixedly provided on the outer peripheral portion of the rotor body. A plurality of permanent magnets are held, and the shielding wall is formed integrally with the permanent magnet holding member .

  The shielding wall provided on the rotor prevents heat transfer due to radiation from the stator to the components of the controller, thereby preventing the temperature of the components from rising.

  In the electric motor unit of the present invention, for example, the rotor has a plurality of permanent magnets held by a synthetic resin permanent magnet holding member fixedly provided on the outer peripheral portion of the rotor body, and the shielding wall is made permanent. It is formed integrally with the magnet holding member.

  In this case, since the permanent magnet holding member is made of synthetic resin, the shielding wall can be easily formed. Further, there is no need to fix the permanent magnet to the rotor body with an adhesive, and there is no possibility of the permanent magnet peeling off.

  The electric pump unit according to the present invention includes the electric motor unit according to the present invention, and is characterized in that a motor housing is fixed to a pump body of a pump that performs suction and discharge of oil.

  Since the motor housing incorporating the pump driving electric motor and the controller is fixed to the pump body of the pump, the electric pump unit can be reduced in weight and size.

  Further, as in the case of the electric motor unit according to the present invention, the temperature rise of the controller components is prevented.

  According to the electric motor unit of the present invention, as described above, it is possible to prevent the temperature rise of the components of the controller.

  According to the electric pump unit of the present invention, as described above, it is possible to reduce the weight and the size, and to prevent the temperature of the controller components from rising.

FIG. 1 is a longitudinal sectional view of a main part of an electric pump unit showing an embodiment of the present invention. FIG. 2 is a cross-sectional view of the main part of the electric pump unit of FIG. FIG. 3 is an enlarged cross-sectional view taken along line III-III in FIG. FIG. 4 is an enlarged cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a virtual exploded perspective view of the rotor of the electric motor.

  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 a main part of an electric pump unit showing an embodiment of the present invention. In the following description, the left side of FIG.

  As shown in FIG. 1, the electric pump unit includes a pump (2) for sucking and discharging oil, an electric motor (3) for driving the pump, and a controller (4) for the electric motor (3) in the unit housing (1). ) Is integrated. 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 body (5) of the pump (2), and a motor housing (6) incorporating an electric motor (3) and a controller (4).

  The pump body (5) includes a rear pump housing (7) and a front pump plate (8). The pump housing (7) has a thick plate shape that extends in a direction orthogonal to the front-rear direction, and a pump chamber (9) having an open front is formed at the center thereof. A pump plate (8) is fixed to the front surface of the pump housing (7) via an O-ring (10), and the front surface of the pump chamber (9) is closed. An outer gear (11) is rotatably accommodated in the pump chamber (9), and an inner gear (12) that meshes with the inner gear (11) is disposed inside the outer gear (11). Although not shown, an oil suction port and an oil discharge port are formed in the pump housing (7) and the pump plate (8), and an oil suction hole and an oil communicating with the oil suction port are formed in the pump plate (8). An oil discharge hole communicating with the discharge port is formed. The pump housing (7) and the pump plate (8) are made of, for example, an aluminum alloy.

  The motor housing (6) includes a cylindrical synthetic resin motor case (13) and a disc-shaped lid (14) fixed to the rear end of the motor case (13). The front end of the motor case (13) is fixed to the rear surface of the pump housing (7) via an O-ring (15). The pump plate (8), the pump housing (7), and the motor case (13) include a plurality of connecting portions (8a), (7a), and (13a) that are integrally formed so as to protrude radially outward from the outer periphery thereof. The parts are secured to each other by bolts (16). The rear end opening of the motor case (13) is closed by the lid (14).

  A cylindrical portion (7b) having a smaller diameter than the motor case (13) is integrally formed at the center of the rear end surface of the pump housing (7), and the bearing device (17) provided at the rear portion in the cylindrical portion (7b) A motor shaft (18) extending in the front-rear direction is cantilevered. In this example, the bearing device (17) is composed of two single row deep groove ball bearings (19) adjacent to the front and rear, and the inner ring (19a) of each bearing (19) is a motor shaft (18). The outer ring (19b) is fixed to the cylindrical portion (7b). In this example, the bearing (19) is a grease lubricated hermetically sealed bearing. The front part of the motor shaft (18) passes through the hole (21) formed in the rear wall of the pump housing (7) and enters the pump chamber (9), and the inner gear (12) Is fitted and fixed. An oil seal (22) is provided between a portion of the cylindrical portion (7b) in front of the bearing device (17) and the motor shaft (18).

  A motor rotor (23) constituting the motor (3) is fixed to a rear end portion of the motor shaft (18) protruding rearward from the cylindrical portion (7b). The rotor (23) extends from the rear end of the motor shaft (18) in the radial direction, and on the outer periphery of a cylindrical rotor body (24) surrounding the outer periphery of the bearing device (17), a permanent magnet holding member made of synthetic resin ( 25) is provided in a fixed shape, and segment-shaped permanent magnets (26) are held at a plurality of locations equally dividing the holding member (25) in the circumferential direction. The axial position of the center of gravity of the rotating part including the motor shaft (18), the rotor (23) and the inner gear (12) of the pump (2) is within the axial range of the bearing device (17). In this example, the axial position of the center of gravity is between the two ball bearings (19) constituting the bearing device (17).

  A motor stator (27) constituting the motor (3) is fixedly provided on the inner periphery of the motor case (13) facing the rotor (23). The stator (27) is an insulator (synthetic resin insulator) (29) incorporated in a stator core (28) made of laminated steel sheets, and a stator coil (30) is wound around the insulator (29). . In this example, the stator (27) is molded integrally with the inner periphery of the motor case (13).

  The board (31) of the controller (4) is fixed to the rear end of the insulator (29), and the component (32) constituting the controller (4) is attached to the board (31). Although only one component (32) attached to the front surface of the substrate (31) is shown in FIG. 1, the component is disposed at a predetermined position on at least one of the front surface and the rear surface of the substrate (31). The component (32) shown in FIG. 1 is, for example, an electrolytic capacitor.

  FIG. 2 is a cross-sectional view (a cross-sectional view seen from the back) showing a molded body of the motor case (13) and the stator (27).

  As shown in FIG. 2, the core (28) has pole portions (tooth portions) protruding radially inward at a plurality of locations (six locations in this example) that equally divide the inner periphery of the annular portion (28a) in the circumferential direction. (28b) is integrally formed. The tip of each pole portion (28b) extends on both sides in the circumferential direction, and its inner peripheral surface forms one cylindrical surface.

  The insulator (29) is composed of a pair of front and rear halves (33) (34). Each half body (33) (34) is formed of a synthetic resin such as PPS (polyphenylene sulfide resin), for example, and a core (28) excluding the outer peripheral surface of the annular portion (28a) and the inner peripheral surface of the pole portion (28b). It is incorporated into the core (28) from both the front and rear sides so as to cover the surface of the core. Each half body (33) (34) is formed with a coil mounting portion (33a) (34a) covering a portion excluding the inner peripheral surface of the pole portion (28b) of the core (28). In each pole part (28b) of the core (28), the coil (30) is wound around the part covered with the coil mounting parts (33a) (34a) of both halves (33) (34). Substrate protrusions (34b) extending backward are integrated into a plurality of locations (six locations in this example) that equally divide the radially outer portion of the coil mounting portion (34a) of the rear half (34) in the circumferential direction. Is formed. A metal female screw member (35) having a female screw formed on the inner periphery is embedded inside the rear end of each protrusion (34b).

  The motor case (13) is integrated with the stator (27) by molding a synthetic resin such as PA66 (polyamide 66) on the outer peripheral side of the stator (27) using a mold. The stator (27) except for the inner peripheral surface of the pole portion (28b) of the core (28), the inner peripheral surface of the coil mounting portion (33a) (34a) of the insulator (29), and the rear end surface of the protrusion (34b). Is covered with a motor case (13). A connector (37) having a plurality of pins (36) is integrally formed on the outer periphery of the motor case (13).

  The lid (14) is made of synthetic resin and is fixed to the rear end of the motor case (13) by an appropriate means such as heat welding.

  The substrate (31) of the controller (4) is fixed to the insulator (29) by a screw (39) screwed to the female screw member (35) of the protrusion (34b) of the insulator (29). Although not shown, a plurality of bus bars are incorporated in the molded body of the insulator (29) and the motor case (13), and the coils (30) of the stator (27) are electrically connected to each other using these bus bars. And electrically connected to the substrate (31). The pin (36) of the connector (37) is also electrically connected to the substrate (31).

  3 to 5 show details of the rotor (23). 3 is an enlarged sectional view taken along line III-III in FIG. 1, FIG. 4 is an enlarged sectional view taken along line IV-IV in FIG. 1, and FIG. 5 is a virtual exploded perspective view of the rotor (23).

  The rotor body (24) is formed by sintering, for example, and is integrally formed on the flange portion (24a) fixed to the motor shaft (18) and the outer peripheral edge of the flange portion (24a). The cylindrical portion (24b) extends forward from the inside of the stator (27) so as to surround the outer periphery of (17). A small diameter portion (18a) formed at the rear end of the motor shaft (18) is fixed by press-fitting into a circular through hole (40) formed at the center of the flange portion (24a). The entire outer peripheral surface of the cylindrical portion (24b) is a cylindrical surface, and the cross-sectional shape of the outer peripheral surface is circular.

  On the outer peripheral part of both ends of the cylindrical part (24b), a rotation-preventing concave part (41) is formed at a plurality of places (eight places in this example) equally divided in the circumferential direction. In this example, the concave portion (41) is formed in the outermost peripheral portion of both end faces of the cylindrical portion (24b), and has a notch shape extending from the outer peripheral portion of the cylindrical portion (24b) to the outer peripheral end portion.

  The holding member (25) is integrated with the cylindrical portion (24b) by molding a synthetic resin into the cylindrical portion (24b) using a mold. The holding member (25) has two annular parts (42) and (43) that are in close contact with both end faces of the cylindrical part (24b), and two circular parts that are in close contact with the outer peripheral surface of the cylindrical part (24b) at a plurality of locations in the circumferential direction. It comprises a plurality of rod-like connecting portions (44) for connecting the ring portions (42) and (43) and holding the permanent magnet (26). A plurality of anti-rotation convex portions (42a) (43a) that fit into the concave portions (41) of the cylindrical portion (24b) are integrally formed on the mutually opposing surfaces of both annular portions (42), (43). Each coupling portion (44) is integrally formed with two engagement holding portions (44a) projecting from the radially outer end to both sides in the circumferential direction. And the permanent magnet (26) is inserted and hold | maintained from the axial direction between the engagement holding | maintenance parts (44a) of the adjacent connection part (44).

  A cylindrical shielding wall (43b) protruding rearward is formed integrally with the rear annular portion (43) of the holding member (25). The shielding wall (43b) is located between the stator (27) and the component (32) on the substrate (31) and shields between them.

  At least one key groove (45) is formed in the through hole (40) of the flange portion (24a) of the rotor body (24). In this example, two key grooves (45) are formed at two symmetrical positions of the hole (40).

  Since the holding member (25) is formed integrally with the rotor body (24), the two are not separated, but in order to facilitate understanding of the configuration of both, in FIG. It is shown as a separate exploded perspective view.

  In the electric pump unit described above, when the electric motor (3) and the pump (2) are operated, heat is generated particularly in the coil (30) portion of the stator (27), so that the stator (27) portion is Although the temperature is high, the shielding wall (43b) formed on the permanent magnet holding member (25) of the rotor (23) causes the stator (27), in particular, the coil (30) to the component (32) on the board (31). Heat transfer due to radiation is hindered and temperature rise of the part (32) is prevented.

  The anti-rotation recess formed in the cylindrical portion (24b) of the rotor body (24) is not a notch-shaped recess (41) extending from the end surface of the cylindrical portion (24b) to the outer peripheral surface as described above, but the cylindrical portion (24b ) May be a bottomed hole formed at one of a plurality of locations on the end surface and the outer peripheral surface, or at a plurality of locations of both. In that case, the detent protrusion of the holding member (25) is provided at a position corresponding to the recess that is a bottomed hole. When the rotor body is a sintered body, it is difficult to process the hole, and thus the notch-shaped recess (41) as described above is preferable.

  In the above embodiment, the motor rotor (23) has a plurality of permanent magnets (26) on the permanent magnet holding member (25) made of synthetic resin fixedly provided on the outer periphery of the cylindrical rotor body (24). Therefore, there is no need to fix the permanent magnet (26) to the rotor body (24) with an adhesive, and there is no possibility of the permanent magnet (26) peeling off.

  In the motor (3) and its rotor (23), when the permanent magnet holding member (25) is integrally formed in the cylindrical portion (24b) of the rotor body (24), the key groove (45) in the hole (40) Can be used for phasing, and the mold and molding process can be simplified. In addition, since the key groove (45) is only provided in the through hole (40) formed in the rotor body (24), the structure of the mold when the rotor body (24) is formed of a sintered body is simplified. The

  Further, since the non-rotating convex portions (42a) and (43a) of the permanent magnet holding member (25) are fitted in the non-rotating concave portion (41) of the rotor body (24), the entire outer peripheral surface of the rotor main body (24) is Even if the cross-sectional shape of the outer peripheral surface of the cylindrical surface is circular, the permanent magnet holding member (25) does not slide in the circumferential direction with respect to the rotor body (24) by rotation, and the permanent magnet holding member (25 ) Is securely fixed. And since the outer peripheral surface of a rotor main body (24) is a cylindrical surface, the process is easy and can be manufactured cheaply.

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

  The present invention can also be applied to an electric pump unit other than the electric pump unit for transmission and an electric motor unit other than the electric pump unit.

(2) Pump
(3) Electric motor
(4) Controller
(5) Pump body
(6) Motor housing
(23) Rotor
(24) Rotor body
(25) Permanent magnet holding member
(26) Permanent magnet
(27) Stator
(32) Parts
(43b) Shielding wall

Claims (2)

An electric motor unit in which an electric motor and a controller that controls the electric motor are housed in a motor housing, and the electric motor includes a stator that is fixed to the motor housing and a rotor that is disposed inside the stator. ,
The rotor is provided with a shielding wall that blocks between the stator and the controller parts ,
The rotor is one in which a plurality of permanent magnets are held on a synthetic resin permanent magnet holding member provided in a fixed manner on the outer peripheral portion of the rotor body,
An electric motor unit , wherein the shielding wall is formed integrally with the permanent magnet holding member . The electric motor unit according to claim 1 is provided,
An electric pump unit characterized in that a motor housing is fixed to a pump body of a pump for sucking and discharging oil.

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