JP2010112328A - Electric pump unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric pump unit having high earthquake resistance and waterproofness, easy in assembling work, and capable of reducing the size and cost. <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 a substrate 26 of the controller 4 is arranged in the opening end part vicinity in the unit housing 1. An opening end part of the unit housing 1 is sealed by a thermosetting viscoelastic heat radiating sealing layer 28 contacting with the substrate 26. <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, it is required to be compact, and to reduce weight and cost. 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 opening end portion of a motor housing constituting the unit housing, and a controller board is disposed inside the lid.
JP 2004-353536 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. Further, in order to increase the dimensional accuracy of the heat radiating member mounting surface of the lid, it is necessary to form the lid with, for example, an aluminum alloy die-cast product, and to accurately process the heat radiating member mounting surface, which is a cause of high cost. . Furthermore, it is necessary to manually attach the heat radiating member, which is difficult.

  The board of the controller of the electric pump unit for automobiles is subject to large vibrations, and there is a risk that parts attached to the board will fall off. For this reason, conventionally, an epoxy resin is attached to a large-sized component that has a high possibility of falling off to improve vibration resistance.

  The portion of the unit housing in which the motor and controller are housed is required to be waterproof, and it is necessary to attach a lid to the unit housing via a seal. However, this increases the number of components, which is a factor that hinders downsizing.

  In order to ensure the air permeability in the sealed housing as described above, the vent filter unit is provided in the lid portion, but the mounting operation is troublesome.

  An object of the present invention is to provide an electric pump unit that solves the above problems, has high earthquake resistance and waterproofness, is easy to assemble, and can be reduced in size and cost.

  An electric pump unit according to the present invention is an electric pump unit in which a pump, an electric motor for driving a pump, and a controller for the motor are incorporated in a unit housing, and a substrate of the controller is disposed in the vicinity of an opening end in the unit housing. The opening end of the unit housing is sealed with a heat-radiating sealing layer made of a thermosetting viscoelastic resin that comes into contact with the substrate.

  As the thermosetting viscoelastic resin, a material having waterproofness and high thermal conductivity, such as urethane resin, is used.

  After the board on which the component is mounted is placed at a predetermined position in the unit housing, the thermosetting viscoelastic resin is filled in the housing on the opening end side of the board so as to surround the part on the board, and this is cured. By doing so, a heat radiation sealing layer is formed.

  Thus, the heat radiation sealing layer can be easily formed simply by filling the housing with the thermosetting viscoelastic resin and curing the resin.

  The heat radiation sealing layer is filled inside the opening end of the housing so as to be in contact with the substrate in a form in which components attached to the substrate are embedded, and seals the opening end. For this reason, even if there is no lid, waterproofness is high, and even when a lid is provided, there is no need for sealing, the number of parts is reduced, and miniaturization and cost reduction are possible. In addition, since the components attached to the substrate are embedded in the heat radiation sealing layer, the vibration resistance is improved and there is no risk of dropping off. The heat generated by the components on the board is radiated to the outside through the heat radiation sealing layer.

  In the electric pump unit of the present invention, for example, a lid is attached to the opening end of the unit housing, and the space between the lid and the substrate is filled with a thermosetting viscoelastic resin and cured, A heat radiation sealing layer is formed.

  After the substrate to which the component is attached is arranged at a predetermined position in the unit housing, the housing on the opening end side of the substrate is filled with thermosetting viscoelastic resin so as to surround the component on the substrate. A lid is attached to the open end. When the resin is cured, a heat radiation sealing layer is formed so as to fill the space in the housing between the lid and the substrate.

  In this case, since the open end of the housing is sealed by the heat radiation sealing layer, it is not necessary to provide a seal between the lid and the housing.

  The heat generated by the components on the board is transmitted to the lid through the heat dissipation sealing layer and radiated to the outside, so there is no need to provide a conventional heat dissipation member between the lid and the components on the board. There is no need to strictly manage the dimensional accuracy, the dimensional accuracy of the heat radiating member mounting surface of the lid, and the dimensional accuracy of the heat radiating member. 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.

  In the electric pon unit of the present invention, for example, a vent filter unit that communicates the inside and outside of the unit housing is embedded in the heat radiation sealing layer.

  The vent filter unit is, for example, a vent filter incorporated in a casing.

  After the substrate to which the component is attached is disposed at a predetermined position in the unit housing, the vent filter unit is disposed, and heat is generated so as to surround the component on the substrate and the vent filter unit in the housing on the opening end side from the substrate. A curable viscoelastic resin is filled. When a lid is provided, the lid is attached to the open end of the housing. Then, as the resin hardens, the space in the housing at the opening end is filled, and the heat radiation sealing layer is formed in a form in which the components on the substrate and the vent filter unit are embedded.

  The vent filter unit ensures ventilation inside and outside the housing.

  The vent filter unit can be incorporated simply by embedding the vent filter unit in the thermosetting viscoelastic resin forming the heat radiation hermetic layer, and the assembly work is easy.

  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 a longitudinal sectional view showing a part of the electric pump unit of FIG. In the following description, the left side of the drawing 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 the lid (8).

  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 the component (27) constituting the controller (4) is attached to the board (26). The component is disposed at a predetermined position on at least one of the front surface and the rear surface of the substrate (26). In the drawing, one component (27) attached to the rear surface of the substrate (26) is shown.

  In the space between the lid (8) and the substrate (26) in the housing (7), a heat-dissipating hermetic sealing layer (28) made of a thermosetting viscoelastic resin is formed, and as shown in FIG. ) Is embedded in the heat radiation sealing layer (28).

  The heat-dissipating sealing layer (28) is embedded in the part (27) attached to the rear surface of the board (26), and is in close contact with the rear surface of the board (26) and the front surface (inner surface) of the lid (8). The open end of (7) is sealed.

  The vent filter unit (29) has a vent filter built into the casing, communicates with the outside air through a hole (30) or notch formed in the lid (8), and is a component of the substrate (26). It communicates with a space in the housing (7) inside the substrate (26) through a notch (31) or a hole formed in the non-exposed portion.

  As the thermosetting viscoelastic resin constituting the heat radiation sealing layer (28), a material having waterproofness and high thermal conductivity, such as urethane resin, is used.

  The heat radiation sealing layer (28) is formed, for example, as follows.

  After the board (26) with the components (27) attached is fixed to the insulator (24) in the housing (7), the vent filter unit (29) is placed in the notch (31) of the board (26). The thermosetting viscoelastic resin is filled in the housing (7) on the opening end side of the substrate (26) so as to surround the component (27) and the vent filter unit (29) on the rear surface of the substrate (26). . Before the resin hardens, the lid (8) is attached to the open end of the housing (7). Then, the resin hardens to fill the space in the housing (7) between the lid (8) and the substrate (26), as well as the components (27) on the rear surface of the substrate (26) and the vent filter unit (29). A heat radiation sealing layer is formed in the form of embedded.

  Thus, the heat radiation sealing layer (28) can be easily formed by simply filling the housing (7) with the thermosetting viscoelastic resin and curing it.

  The heat radiation sealing layer (28) is filled inside the open end of the housing (7) so as to be in contact with the substrate (26) in the form of embedded components (27) attached to the substrate (26). Seal the part. For this reason, even if there is no lid, the waterproof property is high, and even when the lid (8) is provided, there is no need for sealing, the number of parts is reduced, and the size and cost can be reduced. Further, since the component (27) attached to the substrate (26) is embedded in the heat radiation sealing layer (28), the vibration resistance is improved and there is no possibility of dropping off. The heat generated in the component (27) is transferred to the lid (8) through the heat radiation sealing layer (28) and radiated to the outside, so the component (27) on the lid (8) and the board (26) There is no need to provide a heat dissipation member as in the prior art, and it is not necessary to strictly manage the dimensional accuracy of the component (27), the dimensional accuracy of the heat dissipation member mounting surface of the lid (8), and the dimensional accuracy of the heat dissipation member. For this reason, the lid (8) can be made of an inexpensive synthetic resin, not an expensive aluminum alloy die-cast product, and the cost can be reduced. .

  In addition, the vent filter unit (29) ensures ventilation between the inside and outside of the housing (7).

  The vent filter unit can be assembled simply by embedding the vent filter unit (29) in the thermosetting viscoelastic resin forming the heat radiation sealing layer (28), and the assembly work is easy.

  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. FIG. 2 is a longitudinal sectional view showing a part of the electric pump unit of FIG.

Explanation of symbols

(1) Unit housing
(2) Pump
(3) Electric motor
(4) Controller
(8) Lid
(26) Board
(27) Parts
(28) Heat radiation sealing layer
(29) Vent filter unit

Claims (3)

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 controller board is arranged near the opening end in the unit housing,
An electric pump unit characterized in that the opening end of the unit housing is sealed with a thermosetting viscoelastic resin heat radiation sealing layer in contact with the substrate.   A lid is attached to the opening end of the unit housing, and a space between the lid and the substrate is filled with a thermosetting viscoelastic resin and cured to form a heat-dissipating hermetic layer. The electric pump unit according to claim 1, wherein:   The electric pump unit according to claim 1 or 2, wherein a vent filter unit communicating with the inside and outside of the unit housing is embedded in the heat radiation sealing layer.

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