JP2011032979A - Motor-driven pump unit for transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor-driven pump unit for a transmission, which is assembled in the transmission housing of an automobile and in which the water resistance of an electric motor is secured by simple sealing and piping and the electric motor is further miniaturized. <P>SOLUTION: This motor-driven pump unit for a transmission includes a pump 1 having a pump housing 7 with an oil suction port 30 and an oil discharge port 31 and an electric motor 2 for driving the pump. The electric motor 2 which is integrated with a cover 5 for closing the opening of a recess 4 formed in the transmission housing 3 of the transmission is stored in the recess 4 so as to be positioned further on the cover 5 side than the pump 1. The gaps between the cover 5, the pump housing 7, and the transmission housing 3 are sealed. The inside of the recess 4 is partitioned into an opening side space 28 in which the electric motor 2 is contained and a bottom side space 29. An oil O is introduced into the bottom side space 29, and the motor stator 14 is brought into contact with the transmission housing 3. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electric pump unit for a transmission (transmission) of an automobile.

  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 demands, a transmission 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).

JP 2008-215088 A

  The conventional electric pump unit described above is fixed to the outside of the transmission with a screw or the like, and is connected to the transmission by piping.

  For this reason, the unit housing is waterproofed by a seal, and a seal for waterproofing the electrical components of the electric motor and controller is also required inside the unit housing.

  Further, it is necessary to dissipate heat generated by a coil or the like constituting a motor stator of the pump driving electric motor, which causes a problem that the size of the electric pump unit is increased.

  In order to further reduce the size of the electric pump unit, it is conceivable to incorporate a pump and an electric motor for driving the pump into the transmission housing. In that case, the structure of driving the electric motor in oil introduced into the transmission housing for the purpose of miniaturizing the electric motor by oil cooling and eliminating the seal, and driving the electric motor in a waterproof space in the transmission housing One of the structures is adopted.

  In the structure in which the electric motor is driven in oil, there is a problem that the motor efficiency decreases due to the stirring resistance.

  In the structure in which the electric motor is driven in the waterproof space, there is a problem that a complicated seal and piping for the pump are required.

  An object of the present invention is an electric pump unit for a transmission having a pump and an electric motor incorporated in a transmission housing, which solves the above problems, and can ensure waterproofing of the electric motor with a simple seal and piping. Is to provide a device that can be further reduced in size.

  An electric pump unit for transmission according to the present invention is an electric pump unit for transmission that supplies hydraulic pressure to a transmission, and includes a pump having a pump housing provided with an oil suction port and an oil discharge port, and a motor shaft connected to the pump A motor rotor fixedly provided on the motor shaft, and an electric motor for driving the pump having a motor stator disposed around the motor rotor, and a lid for sealing the opening of the recess formed in the transmission housing of the transmission; It is integrated and accommodated in the recess, and the electric motor is located on the lid side from the pump. The gap between the lid and the transmission housing and between the pump housing and the transmission housing are sealed, and the electric motor is in the recess. including It is divided into a mouth side space and a bottom side space, an oil suction port and an oil discharge port are provided on the bottom side space side of the pump housing, oil is introduced into the bottom side space, and the motor stator is attached to the transmission housing. It is characterized by being contacted.

  Since the pump and the electric motor for driving the pump are accommodated in a recess formed in the transmission housing, the unit housing of the conventional electric pump unit is unnecessary, and therefore, further miniaturization of the electric pump portion is possible. .

  For example, O-rings are used for the two seals.

  Waterproofing of the electric motor can be ensured by two relatively simple seals. For this reason, since there is no stirring resistance of an electric motor and motor efficiency improves, the electric motor can be further miniaturized. Further, since the motor stator is in contact with the transmission housing, the heat generated in the motor stator is efficiently radiated to the transmission housing having a large heat capacity, and the electric motor can be further reduced in size. Since oil is introduced only into the bottom space, complicated piping for sucking and discharging oil to the pump is not necessary.

  For example, a motor stator includes a core, an insulator incorporated in the core, and a coil wound around the insulator portion. The lid and the core are fixed to the transmission housing by bolts that are passed through the bolt holes of the core and screwed to the transmission housing.

  In this way, the lid can be fixed to the transmission housing with the bolts, and at the same time, the motor stator can be integrated with the lid, and the contact area between the motor stator and the transmission housing can be increased to increase the heat radiation efficiency. it can.

  For example, an oil suction hole for introducing oil into the bottom space is formed in the transmission housing, the oil suction port is formed in the pump housing so as to face the bottom space, and an oil discharge pipe is connected to the oil discharge port. ing.

  In this case, oil is introduced into the bottom space from an oil suction hole formed in the transmission housing, sucked into the pump from the oil suction port, and discharged from the oil discharge port through the oil discharge pipe. For this reason, only the oil discharge pipe is necessary for the pump, and the structure becomes very simple.

  In the motor rotor, for example, a plurality of permanent magnets are fixed to an outer peripheral portion of a cylindrical rotor body by an appropriate means such as adhesion. In the motor rotor, a plurality of permanent magnets may be held by a synthetic resin permanent magnet holding member fixedly provided on the outer peripheral portion of the cylindrical rotor body.

  The controller of the electric motor may not be provided in the transmission housing, or may be provided in the waterproof opening side space.

  According to the transmission electric pump unit of the present invention, as described above, in a transmission in which a pump and an electric motor are incorporated in a transmission housing, waterproofing of the electric motor can be ensured with a simple seal and piping. For this reason, since there is no stirring resistance of an electric motor and motor efficiency improves, the electric motor can be further miniaturized.

FIG. 1 is a longitudinal sectional view of a main part of an electric pump unit for transmission showing an embodiment of the present invention.

(1) Pump
(2) Electric motor
(3) Transmission housing
(4) Recess
(5) Lid
(6) Electric pump unit
(23) O-ring
(27) O-ring
(7) Pump housing
(12) Motor shaft
(13) Motor rotor
(14) Motor stator
(17) Bolt
(19) Core
(20) Insulator
(21) Coil
(22) Bolt hole
(28) Open side space
(29) Bottom space
(30) Oil inlet
(31) Oil outlet
(32) Oil discharge pipe
(33) Oil suction hole
(29) Oil suction hole
(0) Oil

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a longitudinal cross-sectional view showing portions of a pump (1) and an electric motor (2) for driving a pump of an idle stop electric pump unit (6) of an automobile transmission. In the following description, the left side of FIG. 1 is the front and the right side is the rear.

  The electric pump unit for transmission (6) of the present embodiment is used for auxiliary supply of hydraulic pressure that decreases during idle stop in an automobile transmission. As shown in FIG. 1, the transmission housing of the automobile transmission The vertical vertical wall (3a) constituting (3) is disposed in a recess (4) formed of a bottomed circular hole having an open rear portion formed on the rear surface (outer surface). The pump (1) and the motor (2) are integrated with the lid (5), thereby constituting an electric pump unit (6) for transmission. The motor (2) is disposed on the front surface of the lid (5), and the pump (1) is disposed in front of the motor (2). A pump (1) and a motor (2) are fitted in the recess (4), and a lid (5) seals the rear opening of the hole (4). In this example, the pump (1) is an internal gear pump, and the motor (2) is a DC brushless sensorless motor having a three-phase winding.

  The pump (1) includes a short cylindrical pump housing (7), and an outer gear (outer rotor) (10) is rotatably accommodated in a pump chamber (8) formed in the housing (7). An inner gear (inner rotor) (11) that meshes with the inner gear (11) is arranged inside (10).

  The motor (2) includes a horizontally disposed pump drive motor shaft (12), a motor rotor (13) fixed to a rear portion of the motor shaft (12), and a motor stator ( 14).

  The recess (4) has a stepped shape consisting of a small diameter part (4a) on the bottom side (front side) and a large diameter part (4b) on the opening side (rear side), and an annular end face (4c) between them. ) Are formed with a plurality of screw holes (15).

  The lid (5) has a disc shape, and a relatively thick cylindrical portion (5a) projecting forward is integrally formed on the outer periphery of the lid (5) .The cylindrical portion (5a) has a screw hole (15). A plurality of corresponding bolt holes (16) are formed. The cylindrical part (5a) of the lid (5) is fitted into the large diameter part (4b) of the recess (4) and passed through the bolt hole (16) and screwed into the screw hole (15) as will be described in detail later. It is fixed to the vertical wall (3a) by a plurality of bolts (17) stopped. The inner diameter of the cylindrical portion (5a) is substantially equal to the inner diameter of the small diameter portion (4a) of the recess (4). A small diameter short cylindrical part (5b) concentric with the recess (4) is integrally formed at the center of the front (inner surface) of the lid (5), and a connector (18) is formed on the rear surface (outer surface) of the lid (5). Has been.

  In the stator (14), an insulator (synthetic resin insulator) (20) is incorporated into a core (19) made of laminated steel sheets, and a coil (21) is wound around the insulator (20). The outer diameter of the core (19) is substantially equal to the inner diameter of the large diameter portion (4b) of the recess (4). The outer diameter of the insulator (20) is slightly smaller than the inner diameter of the small diameter portion (4a) of the recess (4). A plurality of bolt holes (22) corresponding to the bolt holes (16) of the lid (5) are formed in a portion of the core (19) projecting radially outward from the insulator (20). The outer peripheral portion of the core (19) is closely fitted to the front portion of the large diameter portion (4b) of the recess (4), and the front surface thereof is in pressure contact with the annular end surface (4c) of the recess (4). The front part of the cylindrical part (5a) of the lid (5) is fitted into the large diameter part (4b) of the recess (4) on the rear side of the core (19), and the bolt (17) is attached to the cylindrical part (5a). It is passed through the bolt hole (16) and the bolt hole (22) of the core (19) and screwed into the screw hole (15), whereby the lid (5) is fixed to the vertical wall (3a) and the core The outer periphery of (19) is clamped between the annular end surface (4c) of the recess (4) and the front end surface of the cylindrical portion (5a) of the lid (5). As a result, both end surfaces of the outer peripheral portion of the core (19) and a relatively large portion of the outer peripheral surface are in contact with the vertical wall (3a) and the lid (5). An O-ring (23) constituting a seal is provided between the outer periphery of the cylindrical portion (5a) of the lid (5) and the inner periphery of the large diameter portion (4b). The rear end surface of the insulator (20) is in contact with the front surface of the lid (5). Although not shown, the coil (21) is connected to the connector (18). The rear end surface of the pump housing (7) is fixed to the front end surface of the insulator (20) by appropriate means such as adhesion.

  The rear end portion of the motor shaft (12) is rotatably supported by a bearing device (24) provided in the small diameter short cylindrical portion (5b) of the lid (5). In this example, the bearing device (24) is composed of a ball bearing which is a single rolling bearing. The front part of the motor shaft (12) passes through the hole (25) formed in the rear wall (7a) of the pump housing (7) and enters the pump chamber (8). It is connected to the inner gear (11) of (1). An oil seal (35) is provided between the motor shaft (12) and the peripheral wall of the hole (25). The rotor (13) has a cylindrical shape extending radially outward from the rear portion of the motor shaft (12) and surrounding the motor shaft (12) inside the stator (14), and a permanent magnet (26) is disposed on the outer periphery thereof. Is provided.

  The pump housing (7) is closely packed in the small diameter portion (4a) of the recess (4), and the O-ring (27) is provided between the outer periphery of the pump housing (7) and the inner periphery of the small diameter portion (4a). It is sealed. And by the two O-rings (23) and (27), the recess (4) has a relatively large waterproof opening side space (28) including the motor (2) on the rear side of the pump housing (7). And a relatively small bottom space (29) on the front side of the pump housing (7). An oil suction port (30) is formed in the lower part of the front wall (7b) of the pump housing (7) on the bottom space (29) side, and an oil discharge port (31) is formed in the upper part. The oil discharge pipe (32) is connected. The discharge pipe (32) passes through the bottom wall (3b) of the recess (4) of the transmission housing (3) and is not shown, but is connected to a required part of the transmission or other It is connected to the required part of the transmission through a pipe.

  An oil suction hole (33) communicating with an oil pan (not shown) is formed in the lower part of the bottom wall (3b) of the recess (4) of the housing vertical wall (3a), and through this hole (33), the bottom space ( 29) Oil (0) is placed inside. The pump housing (7) is immersed in the oil (0) up to a portion above the oil suction port (30).

  A controller (not shown) of the motor (2) is disposed outside the transmission and connected to the motor (2) via the connector (18) of the lid (5).

  While the vehicle is running, the motor (2) is stopped, and therefore the pump (1) is also stopped.

  While the vehicle is stopped, the motor (2) operates, whereby the pump (1) also operates. When the pump (2) is operated, the oil (0) in the bottom space (29) is sucked from the suction port (30) and discharged from the discharge port (31) to the discharge pipe (32). ) To the required part of the transmission.

  In the transmission electric pump unit (6), the pump (1) and the pump drive electric motor (2) are provided in the transmission housing (3), so the unit housing of the conventional electric pump unit is unnecessary. is there. Therefore, it is possible to make the electric pump portion compact and reduce the weight and cost. Since the electric pump (2) operates while the vehicle is stopped, the height of the oil level (0a) can be managed only by managing the amount of hydraulic oil (0).

  The waterproofing of the electric motor (2) can be ensured by the two O-rings (23) and (27). For this reason, since there is no stirring resistance of the electric motor (2) and the motor efficiency is improved, the electric motor (2) can be further reduced in size. Since oil is introduced only into the bottom space (25), complicated piping for sucking and discharging oil to the pump (1) is unnecessary. In the above example, only the oil discharge pipe (28) is required for the pump (1), and the structure is very simple.

  Since the relatively large area of the core (19) of the motor stator (14) is in contact with the transmission housing (3) having a large heat capacity, the heat generated in the stator (14) is efficiently dissipated. The outer periphery of the insulator (20) of the motor stator (14) is brought into contact with the inner periphery of the small diameter portion (4a) of the recess (4) and the inner periphery of the cylindrical portion (5a) of the lid (5). You may make it perform heat dissipation from.

  The configuration of each part of the electric pump unit for transmission (6) is not limited to that of the above embodiment, and can be changed as appropriate.

  For example, in the above embodiment, in the motor rotor (13), the plurality of permanent magnets (26) are fixed to the outer periphery of the cylindrical rotor body (34) by appropriate means such as adhesion, but the rotor body (34) A plurality of permanent magnets may be held on a synthetic resin permanent magnet holding member provided in a fixed manner on the outer periphery of the magnet.

Claims (3)

An electric pump unit for transmission that supplies hydraulic pressure to the transmission,
Pump having a pump housing having an oil inlet and an oil outlet, a motor shaft connected to the pump, a motor rotor fixed to the motor shaft, and a motor stator arranged around the motor rotor An electric motor, and is integrated with a lid that seals the opening of the recess formed in the transmission housing of the transmission, is housed in the recess, and the electric motor is located on the lid side from the pump,
The space between the lid and the transmission housing and the space between the pump housing and the transmission housing are respectively sealed, and the inside of the recess is partitioned into an opening side space including an electric motor and a bottom side space,
An oil suction port and an oil discharge port are provided on the bottom space side of the pump housing, and oil is introduced into the bottom space,
An electric pump unit for transmission, wherein the motor stator is in contact with the transmission housing.   The motor stator includes a core, an insulator incorporated in the core, and a coil wound around the insulator portion, and a bolt hole is formed in the core portion whose outer diameter is larger than the insulator, and the lid and 2. The electric pump unit for transmission according to claim 1, wherein the lid and the core are fixed to the transmission housing by bolts which are passed through the bolt holes and screwed to the transmission housing.   An oil suction hole for introducing oil into the bottom space is formed in the transmission housing, the oil suction port is formed in the pump housing so as to face the bottom space, and an oil discharge pipe is connected to the oil discharge port The electric pump unit for transmission according to claim 1 or 2, wherein

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