JP2010112330A - Electric pump unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric pump unit capable of reducing cost, by facilitating installation work of a heat radiating member. <P>SOLUTION: This electric pump unit is provided by incorporating a pump 2, a pump driving electric motor 3 and a controller 4 of the motor 3 into a unit housing 1, and the heat radiating member 29 is arranged between a part 27 installed on a substrate 26 of the controller 4 and a cover 8 of the unit housing 1. The heat radiating member 29 is hardened by applying a thermosetting viscoelastic resin to the cover 8. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric pump unit used as, for example, a hydraulic pump of an automobile.

  In recent years, as a hydraulic pump for automobiles, it has been designed to save energy by finely controlling its start and stop, and to ensure the supply of hydraulic pressure to the drive system such as the transmission even when the engine is stopped due to idling stop In addition, an electric pump unit is used.

  Since the electric pump unit for automobiles is mounted in a limited space of the vehicle body, downsizing is required, and weight reduction and cost reduction are also required. As an electric pump unit that meets this requirement, an electric pump unit in which a pump, an electric motor for driving a pump, and a controller for the motor are integrally incorporated in a common unit housing has been proposed (for example, see Patent Document 1).

In this electric pump unit, a lid is fixed to an end portion of a motor housing constituting the unit housing, and a controller board is disposed inside the lid.
JP 2005-337095 A

  The electric pump unit for automobiles is mounted in the engine room of automobiles, and since the components (elements) on the controller board generate heat, it is necessary to dissipate the board. A heat dissipating member is disposed on the surface. For the heat radiating member, silicone rubber having high thermal conductivity is used. Silicone rubber has viscoelasticity, but if the distance between the parts on the board and the heat radiating member mounting surface of the lid is too large, the contact between the parts and the lid and the heat radiating member is insufficient, the heat radiation effect is small, conversely, If the mutual distance is too small, an excessive load is applied to the substrate, which is not preferable.

  For this reason, it is necessary to manage the dimensional (height) accuracy of the heat radiating member mounting surface of the lid and the component, but it is difficult to manage the dimensional accuracy of the component. In addition, in order to increase the dimensional accuracy of the heat radiating member mounting surface of the lid, it is necessary to configure the lid with, for example, an aluminum alloy die-cast product, and to accurately process the heat radiating member mounting surface, which is a factor of high cost. . Furthermore, it is necessary to manually attach the heat radiating member, which is difficult.

  An object of the present invention is to provide an electric pump unit that solves the above-described problems and that is easy to attach a heat radiating member and can reduce the cost.

  In the electric pump unit according to the present invention, the pump, the electric motor for driving the pump, and the controller of the motor are incorporated in the unit housing, and the heat radiating member is disposed between the component mounted on the controller board and the lid of the unit housing. In the electric pump unit, the heat dissipating member is one in which a thermosetting viscoelastic resin is applied to the lid and cured.

  Before the cover is attached to the unit housing, the thermosetting viscoelastic resin is applied to the surface of the cover that faces a part that requires a heat dissipation member when attached to the unit housing. The thickness of the resin to be applied is a little thicker than the distance between the component and the surface of the lid facing the component, and the lid is attached to the unit housing before the resin is cured. When the lid is attached, the applied resin adheres to the part. At this time, since the resin is not yet cured, the resin is deformed into a shape in which the space between the component and the lid is filled and cured to become a heat radiating member.

  The heat generated in the parts during use of the electric pump unit is transmitted to the lid through the heat radiating member and radiated to the outside.

  It is only necessary to apply a little thick resin to the lid and attach the lid to the unit housing, and the mounting operation of the heat radiating member is very simple.

  Further, it is not necessary to strictly manage the dimensional accuracy of the parts, the dimensional accuracy of the heat radiating member mounting surface of the lid, and the thickness of the resin applied to the lid. For this reason, the lid can be made of an inexpensive synthetic resin instead of an expensive aluminum alloy die-cast product, and the cost can be reduced.

  The distance between the component and the heat radiating member mounting surface of the lid is arbitrary, but it is preferable that the distance is relatively small, for example, about 1 mm.

  As the thermosetting viscoelastic resin, a material having high thermal conductivity, such as silicone rubber, is used.

  In the electric pump unit according to the present invention, for example, a projection for applying a heat radiation member is formed on the lid, and a thermosetting viscoelastic resin is applied to an end surface of the projection.

  The convex portion is formed on a portion of the lid that faces a part that requires a heat radiating member.

  The thermosetting viscoelastic resin is applied to the end face of the convex portion, that is, the heat dissipating member attaching surface, before attaching the lid to the unit housing. The rest is the same as above.

  In this case, since the convex portion is formed, there is an advantage that the portion where the resin is to be applied becomes clear.

  When there is one component that requires a heat dissipating member, the convex portion is formed at one location facing this component. When there are a plurality of parts that require a heat dissipating member, one or a plurality of convex portions may be provided. In this case, the heat radiating member may correspond to one component or may correspond to a plurality of components. When the heat dissipating member corresponds to a plurality of parts, the resin may be applied to the entire end face of the heat dissipating member, or may be applied only to a part facing the end face part.

  According to the electric pump unit of the present invention, as described above, the heat dissipating member can be easily attached and the cost can be reduced.

  Embodiments in which the present invention is applied to an automobile hydraulic pump will be described below with reference to the drawings.

  FIG. 1 is a longitudinal sectional view of an electric pump unit showing an embodiment of the present invention, and FIG. 2 is an enlarged sectional view taken along line II-II in FIG. 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 an electric motor (3) for rotationally driving the pump (2) are integrated. The controller (4) of the motor (3) is also incorporated in the housing (1). In this example, the pump (2) is a trochoid pump, and the motor (3) is a DC brushless sensorless motor having a three-phase winding.

  The unit housing (1) consists of a pump housing (5), pump plate (6), motor housing (7) and lid (8), and is waterproof by the pump housing (5), motor housing (7) and lid (8). A housing (9) is constructed.

  The pump housing (5) has a thick plate shape that extends in a direction perpendicular to the front-rear direction, and a pump chamber (10) having an open front is formed at the center thereof. A pump plate (6) is fixed to the front surface of the pump housing (5) via an O-ring (11), and the front surface 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 pump plate (6) is provided with an oil inlet and an oil outlet.

  The motor housing (7) has a cylindrical shape, and its front end is fixed to a portion near the outer periphery of the rear surface of the pump housing (5) via a seal (14). The rear end opening of the motor housing (7) is closed by a lid (8) through a seal (not shown).

  A cylindrical portion (5a) having a smaller diameter than the motor housing (7) is integrally formed at the center of the rear end surface of the pump housing (5), and a bearing device (15) provided at the rear portion in the cylindrical portion (5a) A pump drive motor shaft (16) extending in the front-rear direction is cantilevered. In this example, the bearing device (15) includes two ball bearings (17) that are adjacent to the front and rear, and the inner ring (17a) of each bearing (17) is fixed to the motor shaft (16). The outer ring (17b) is fixed to the cylindrical portion (5a). The front part of the motor shaft (16) passes through the hole (18) formed in the rear wall of the pump housing (5) and enters the pump chamber (10), and the front end of the motor shaft (16) reaches the inner gear (13). It is connected. A seal (19) is provided between a portion of the cylindrical portion (5a) in front of the bearing device (15) and the motor shaft (16).

  A motor rotor (20) constituting the motor (3) is fixed to a rear end portion of the motor shaft (16) protruding rearward from the cylindrical portion (5a). The rotor (20) has a cylindrical shape extending in the radial direction from the rear end of the motor shaft (16) and surrounding the outer periphery of the bearing device (15), and a permanent magnet (21) is provided on the outer periphery. The axial position of the center of gravity of the rotating portion including the motor shaft (16), the rotor (20), and the inner gear (13) of the pump (2) is within the axial range of the bearing device (15). In this example, the axial position of the center of gravity is between the two ball bearings (17) constituting the bearing device (15).

  A motor stator (22) constituting the motor (3) is fixedly provided on the inner periphery of the motor housing (7) facing the rotor (20). In the stator (22), an insulator (synthetic resin insulator) (24) is incorporated in a core (23) made of laminated steel plates, and a coil (25) is wound around the insulator (24). In this example, the stator (22) is fixed to the inner periphery of the motor housing (7) by an appropriate means such as adhesion on the outer periphery of the core (23).

  The board (26) of the controller (4) is fixed to the rear end of the insulator (24), and a component (27) constituting the controller (4) is attached to the board (26). The components are arranged at a predetermined position on at least one of the front surface and the rear surface of the board (26). In the drawing, three components (27) that are attached to the rear surface of the board (26) and require heat dissipation are shown. Yes. The heights of these three parts are roughly aligned.

  On the front surface (inner surface) of the lid (8), one heat radiation member application convex portion (28) corresponding to the illustrated component (27) is integrally formed. The front surface (radiation member mounting surface) of the convex portion (28) is a flat surface substantially parallel to the substrate (26), and the heat radiation member made of thermosetting viscoelastic resin is between this surface and the component (27). (29) is provided.

  The interval between the component (27) and the convex portion (28) of the lid (8) is arbitrary, but it is preferable that it is relatively small, for example, about 1 mm.

  As the thermosetting viscoelastic resin constituting the heat dissipating member (29), a material having high thermal conductivity, such as silicone rubber, is used.

  Before attaching the lid (8) to the motor housing (7), a thermosetting viscoelastic resin is applied to the entire front surface of the convex portion (28). The thickness of the resin to be applied is slightly larger than the distance between the component (27) and the convex portion (28), and the lid (8) is attached to the unit housing (7) before the resin is cured. When the lid (8) is attached, the applied resin comes into close contact with the component (27). At this time, since the resin is not yet cured, the resin is deformed into a shape in which the space between the component (27) and the convex portion (28) is filled and cured, thereby forming the heat radiating member (29).

  Heat generated in the component (27) during use of the electric pump unit is transmitted to the lid (8) through the heat radiating member (29), and is radiated to the outside.

  It is only necessary to apply a little thick resin to the lid and attach the lid (8) to the motor housing (7), and the attaching operation of the heat radiating member (29) is very simple.

  In addition, it is not necessary to strictly control the dimensional accuracy of the component (27), the dimensional accuracy of the heat sink mounting surface of the convex portion (28) of the lid (8), and the thickness of the resin applied to the convex portion (28). . For this reason, the lid (8) can be made of an inexpensive synthetic resin instead of an expensive aluminum alloy die-cast product, and the cost can be reduced.

  In the above example, the resin is applied to the entire front surface of the convex portion (28), but the resin is applied only to the position corresponding to the component (27) on the front surface of the convex portion (28), and each component (27 ), A heat radiating member (29) may be provided between the convex portion (28).

  When there is one component (27) that requires the heat dissipating member (29), the convex portion (28) is formed at one location of the lid (8) facing this component (28). When there are a plurality of parts (27) that require the heat dissipating member (27), one or a plurality of convex portions (28) may be provided. In this case, the heat radiating member (29) may correspond to one component (27) or may correspond to a plurality of components (27).

  When a part that requires heat dissipation is also attached to the front of the board (26), the part is placed on the front side of the part (27) on the rear side of the board (26) on which the heat dissipation member (29) is provided. The heat generated by the heat can be dissipated through the heat dissipating member (29).

  Note that the resin may be directly applied to a position facing the component (27) on the front surface of the lid (8) without providing the convex portion (28) on the lid (8).

  In the electric pump unit, one axial position of the motor shaft (16) is cantilevered by the bearing device (15), and the motor rotor (20) is provided so as to surround the outer periphery of the bearing device (15). Because of the structure, the length of the motor shaft (16) can be shortened, and further downsizing is possible. Further, since the axial position of the center of gravity of the rotating part including the motor shaft (16), the motor rotor (20) and the inner gear (13) of the pump (2) is within the axial range of the bearing device (15), the rotating part Can be stably rotated. Furthermore, since the position of the center of gravity in the axial direction is between the two ball bearings (17) constituting the bearing device (15), the rotating part can be supported in a more stable manner. Further, the bearing device (15) can be supported only by the cylindrical portion (5a) formed integrally with the pump housing (5), and no other member for supporting the bearing device (15) is required. For this reason, the number of parts can be further reduced, and further weight reduction and cost reduction are possible.

  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.

  For example, in the above embodiment, the bearing device is configured by a rolling bearing, but the bearing device may be configured by a slide bearing.

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

FIG. 1 is a longitudinal sectional view of an electric pump unit showing a first embodiment of the present invention. 2 is an enlarged cross-sectional view taken along line II-II in FIG.

Explanation of symbols

(1) Unit housing
(2) Pump
(3) Electric motor
(4) Controller
(8) Lid
(26) Board
(27) Parts
(28) Convex part for heat radiation member application
(29) Heat dissipation member

Claims (2)

In the electric pump unit in which the pump, the electric motor for driving the pump and the controller of the motor are incorporated in the unit housing, and the heat radiating member is arranged between the component mounted on the controller board and the lid of the unit housing,
An electric pump unit characterized in that the heat radiating member is formed by applying a thermosetting viscoelastic resin to a lid and curing the heat radiating member.   The electric pump unit according to claim 1, wherein a convex part for applying a heat radiation member is formed on the lid, and a thermosetting viscoelastic resin is applied to an end surface of the convex part.

Images