JP5418053B2 - Electric pump unit for transmission - Google Patents

Description

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

  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, 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 to provide an electric pump unit for a transmission having a pump and an electric motor incorporated in a transmission housing, which can secure the waterproofing of the electric motor with a simple seal and piping. There is to do.

  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 an electric motor for driving the pump. And is integrated with a lid that seals the opening of the recess formed in the transmission housing, and is housed in the recess, and the electric motor is located on the lid side of the pump, and between the lid and the transmission housing and between the pump The space between the housing and the transmission housing is sealed, and the inside of the recess is divided into an opening side space including the electric motor and a bottom side space, and an oil suction port and an oil discharge port are provided on the bottom side space side of the pump housing. The oil is introduced into the bottom space. It is intended.

  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. Since oil is introduced only into the bottom side space, complicated piping for sucking and discharging oil to the pump is unnecessary.

  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.

  The electric motor includes, for example, a motor shaft connected to a pump, a motor rotor fixed to the motor shaft, and a motor rotor disposed around the motor rotor. The motor stator is fixed to the lid, and the pump housing is fixed to the motor stator. Preferably, a part of the motor stator is in contact with the pump housing. In this way, 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 downsized.

  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
(7) Pump housing
(16) O-ring
(23) O-ring
(24) Open space
(25) Bottom space
(26) Oil inlet
(27) Oil outlet
(28) Oil discharge pipe
(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). At the rear end portion of the recess (4), the peripheral wall (4a) is removed to form an enlarged diameter portion (4b). 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 lid (5) has a disc shape, and is fixed to the rear surface of the vertical wall (3a) by an appropriate means such as a bolt (not shown) around the recess (4). A small-diameter short cylindrical portion (5a) and a large-diameter short cylindrical portion (5b) concentric with the recess (4) are integrally formed on the front surface (inner surface) of the lid (5), and the rear surface (outer surface) of the lid (5) A connector (15) is formed on the top. The large diameter short cylindrical part (5b) fits into the enlarged diameter part (4b) of the recess (4), and the inner peripheral surface of the short cylindrical part (5b) extends the peripheral wall (4a) of the recess (4). It has become. An O-ring (16) constituting a seal is provided between the outer periphery of the short cylindrical portion (5b) and the inner periphery of the enlarged diameter portion (4b).

  In the stator (14), an insulator (synthetic resin insulator) (18) is incorporated in a core (17) made of laminated steel plates, and a coil (19) is wound around the insulator (18). The rear end surface of the insulator (18) is fixed to the front surface of the lid (5) by appropriate means such as adhesion. A part of the stator (14) is in contact with the peripheral wall (4a) of the recess (4). Although not shown, the coil (19) is connected to the connector (15). The rear end surface of the pump housing (7) is fixed to the front end surface of the insulator (18) by appropriate means such as adhesion. The rear end portion of the motor shaft (12) is rotatably supported by a bearing device (20) provided in the small diameter short cylindrical portion (5a) of the lid (5). In this example, the bearing device (20) is composed of a ball bearing which is a single rolling bearing. The front part of the motor shaft (12) penetrates the part of the hole (21) formed in the rear wall (7a) of the pump housing (7) and enters the pump chamber (8), and its front end part is the pump It is connected to the inner gear (11) of (1). An oil seal (31) is provided between the motor shaft (12) and the peripheral wall of the hole (21). 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 (22) is disposed on the outer periphery thereof. Is provided.

  The pump housing (7) is closely packed in the recess (4), and the space between the outer periphery of the pump housing (7) and the peripheral wall (4a) of the recess (4) is sealed by an O-ring (23). . And, by the two O-rings (16) and (23), the recess (4) has a relatively large waterproof opening side space (24) including the motor (2) on the rear side of the pump housing (7). And a relatively small bottom space (25) on the front side of the pump housing (7). An oil inlet (26) is formed in the lower part of the front wall (7b) of the pump housing (7) on the bottom space (25) side, and an oil outlet (27) is formed in the upper part. A discharge pipe (28) is connected. The discharge pipe (28) 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 (29) 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 (29), the bottom side space ( 25) Oil (0) can enter. The oil is then immersed in the oil (0) up to a portion above the oil suction port (26) of the pump housing (7).

  The controller (not shown) of the motor (2) is disposed outside the transmission and connected to the motor (2) via the connector (15) 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 (25) is sucked from the suction port (26), discharged from the discharge port (27) to the discharge pipe (28), and discharged to the discharge pipe (28 ) 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 (16) and (23). 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 downsized. 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 part 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 radiated.

  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 (22) are fixed to the outer periphery of the cylindrical rotor body (30) by appropriate means such as adhesion, but the rotor body (30) A plurality of permanent magnets may be held by a synthetic resin permanent magnet holding member that is fixedly provided on the outer periphery of the synthetic resin.

Claims (2)

An electric pump unit for transmission that supplies hydraulic pressure to the transmission,
A pump having a pump housing provided with an oil suction port and an oil discharge port, and an electric motor for driving the pump, and integrated with a lid for sealing the opening of the recess formed in the transmission housing, The electric motor is located on the lid side of 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 electric pump unit for transmission, wherein 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 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.

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