JP2014001637A - Electric pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric pump device capable of improving a cooling performance.SOLUTION: A rotor 42 constituting a motor of an electric pump device comprises: plural permanent magnets 47 arranged on an outer periphery of a rotor core 46; and a holder 48 having plural arms 51 arranged between the adjacent permanent magnets 47. Then, claw sections 54, 55 respectively projecting on both sides in a circumferential direction to hold the permanent magnets 47 are formed on the arms 51, and the claw section 54 arranged on a front side in a rotation direction of the rotor 42 is formed so that one axial end thereof projects more largely than the other axial end.

Description

  The present invention relates to an electric pump device.

  Conventionally, as an electric pump device that generates hydraulic pressure by driving a pump with a motor, there is one in which the pump and the motor are housed and integrated in a common housing. Such an electric pump device is mounted on a vehicle having a so-called idle stop function that automatically stops the engine when the vehicle is temporarily stopped, for example, and ensures supply of hydraulic pressure to the transmission or the like at the time of idle stop.

  Further, in such an electric pump device, a pump chamber in which the pump in the housing is accommodated and a motor chamber in which the motor is accommodated are communicated via a communication hole, and hydraulic oil is supplied to the pump chamber via the motor chamber. There are ones (for example, Patent Document 1) and those in which the pump chamber and the motor chamber are partitioned in an airtight manner and hydraulic oil is directly supplied to the pump chamber (for example, Patent Document 2). And in the former electric pump device, there exists an advantage that a motor can be cooled with hydraulic oil.

Japanese Patent Laid-Open No. 5-122901 JP 2010-112330 A

  In recent years, in the electric pump device as described in Patent Document 1, higher cooling performance has been demanded, and creation of a new technology capable of realizing further improvement in cooling performance has been demanded. It was.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an electric pump device capable of improving the cooling performance.

  In order to achieve the above object, an invention according to claim 1 is provided with a pump that generates hydraulic pressure, a motor that drives the pump, and a housing that integrally accommodates the pump and the motor. Is formed with a suction flow path opened in the motor chamber in which the motor is accommodated and a discharge flow path opened in the pump chamber in which the pump is accommodated, and a communication hole for communicating the motor chamber and the pump chamber The hydraulic fluid is sucked into the pump chamber from the suction flow path through the motor chamber and the communication hole by rotating the rotor of the motor and driving the pump. In the electric pump device discharged from the road, the rotor includes a plurality of permanent magnets disposed on the outer periphery of the rotor core and a plurality of arms disposed between the adjacent permanent magnets. The arm is formed with a claw portion that protrudes on both sides in the circumferential direction to hold the permanent magnet, and the claw portion disposed on the front side in the rotation direction of the rotor has one end side in the axial direction. The gist is that is formed so as to protrude larger than the other end in the axial direction.

  According to the above configuration, the hydraulic oil that hits the claw portion due to the rotation of the rotor flows from one axial end to the other axial end. This makes it difficult for the flow of hydraulic oil to stagnate in the motor chamber, so that the cooling performance of the motor can be improved.

The invention according to claim 2 is the electric pump device according to claim 1, wherein the rotor core is formed with a through hole penetrating in the axial direction.
According to the said structure, it becomes possible for the hydraulic fluid which flowed from the axial direction one end side to the axial other end side to return to an axial direction one end side via a flow hole. Accordingly, the hydraulic oil is easily circulated in the motor chamber, and the flow of the hydraulic oil is more difficult to stagnate.

  According to a third aspect of the present invention, in the electric pump device according to the second aspect of the present invention, the opening on the one end side in the axial direction is positioned more radially outward than the opening on the other end side in the axial direction. The gist is that it was formed.

  According to the above configuration, the hydraulic oil in the flow hole is sent from the other axial end side to the one axial end side by the centrifugal force accompanying the rotation of the rotor. As a result, the hydraulic oil is more easily circulated in the motor chamber, and the flow of the hydraulic oil is more difficult to stagnate.

  According to a fourth aspect of the present invention, in the electric pump device according to any one of the first to third aspects, the housing is provided with a control chamber that is partitioned in a state in which hydraulic oil is prevented from entering. The control chamber contains a control device for controlling the operation of the motor, and the pump chamber is provided at one axial end of the motor chamber and the other axial end of the motor chamber. The gist is that the control chamber is provided on the side, and the suction flow path is formed at a position near the pump chamber in the housing.

  In order to more reliably prevent hydraulic oil from entering the control chamber, it is preferable to provide an interval greater than a predetermined interval between the control chamber and the suction flow path, and the suction flow path is formed at a position near the control chamber. In this case, the housing is easily increased in size. Therefore, it is possible to suppress an increase in the size of the housing by forming the suction flow path near the pump chamber as in the above configuration. In this case, the suction flow path and the communication hole are connected to the shaft in the motor chamber. Since it is arranged close to the one end side in the direction (pump chamber side), it becomes difficult for hydraulic oil to flow to the other end side in the axial direction (control chamber side). In this regard, in the above configuration, the hydraulic oil is caused to flow to the other axial end side (control chamber side) by the claw portion, so that the cooling performance can be effectively improved while suppressing an increase in the size of the housing.

  ADVANTAGE OF THE INVENTION According to this invention, the electric pump apparatus which can improve cooling performance can be provided.

Sectional drawing of the electric pump apparatus of one Embodiment. The end view of the rotor of one embodiment (the AA end view of Drawing 1). The side view of the rotor of one Embodiment. The schematic diagram which shows the flow of the hydraulic fluid in the motor chamber of one Embodiment. (A)-(e) is a side view of the rotor of another example.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
An electric pump device 1 shown in FIG. 1 is mounted on, for example, a vehicle having an idle stop function, and is used to ensure hydraulic pressure supply to a transmission or the like at the time of idle stop. As shown in the figure, the electric pump device 1 includes a housing 2 formed in a substantially cylindrical shape. In the housing 2, a pump 3 that generates hydraulic pressure, a motor 4 that drives the pump 3, and a control board 5 as a control device that controls the operation of the motor 4 are integrally accommodated.

  More specifically, the housing 2 includes a bottomed cylindrical pump case 11 that is open on one axial end side (the right side in FIG. 1), a pump plate 12 that is disposed so as to close the opening of the pump case 11, a shaft And a bottomed cylindrical motor case 13 having one end opened in the direction. The pump case 11 is accommodated on the opening end side of the motor case 13, and the opening of the motor case 13 is closed by the pump plate 12. Further, the motor case 13 is formed with a cylindrical extending portion 13b extending from the bottom portion 13a to the other axial end side (left side in FIG. 1), and the opening end of the extending portion 13b is a disc. The cover 14 is closed. The inside of the pump case 11 is configured as a pump chamber 15 that houses the pump 3, the inside of the cylinder portion 13 c of the motor case 13 is configured as the motor chamber 16 that houses the motor 4, and the inside of the extending portion 13 b is the control board 5. It is configured as a control room 17 for housing. That is, the pump chamber 15 is provided on one axial end side of the motor chamber 16, and the control chamber 17 is provided on the other axial end side of the motor chamber 16. The pump case 11 and the pump plate 12 are made of a metal material, and the motor case 13 and the cover 14 are made of a resin material.

  The cylinder portion 13c of the motor case 13 is formed with a suction passage 21 that communicates the motor chamber 16 with the outside. The hydraulic oil 22 is supplied from an external opening 21a (suction port) that opens to the outside of the suction passage 21. It is designed to be sucked into the motor chamber 16. The suction flow path 21 is formed in a substantially linear shape, and is formed at a position near the pump chamber 15 (one axial end side) in the cylindrical portion 13c. In addition, a communication hole 23 is formed in the bottom portion 11 a of the pump case 11 so as to penetrate the pump chamber 15 and the motor chamber 16 in the axial direction. In the pump chamber 15, the communication hole 23 is formed at a position where a gap between an outer gear 31 and an inner gear 32 of the pump 3 which will be described later increases as the motor 4 rotates. The pump plate 12 is formed with a discharge flow path 24 that communicates the pump chamber 15 with the outside, and the pump chamber 12 operates in the pump chamber 15 from an external opening 24 a (discharge port) that opens to the outside of the discharge flow path 24. Oil 22 is discharged. Further, the internal opening 24 b that opens to the pump chamber 15 of the discharge flow path 24 is formed at a position where a gap formed between the outer gear 31 and the inner gear 32 in the pump chamber 15 becomes smaller as the motor 4 rotates. Yes.

  The control chamber 17 is partitioned in a state (liquid-tight) in which the hydraulic oil 22 is prevented from entering from the motor chamber 16 by the bottom 13 a of the motor case 13. Further, the space between the cylinder portion 13c of the motor case 13 and the pump plate 12 is sealed by a seal member 25 such as an O-ring.

  As the pump 3, a trochoid pump (internal gear pump) is employed. Specifically, the pump 3 includes an outer gear 31 having teeth on the inner periphery and an inner gear 32 having teeth on the outer periphery. And the outer gear 31 is arrange | positioned rotatably in the pump chamber 15, and the inner gear 32 is arrange | positioned in the inner periphery of the outer gear 31 in the state which a part of tooth | gear part meshed | engaged.

  The motor 4 is a brushless motor. Specifically, the motor 4 includes a stator 41 that is fixed in the motor chamber 16 and a rotor 42 that is rotatably disposed on the inner periphery of the stator 41. The stator 41 is formed by winding a coil 44 around a tooth 43a of a stator core 43 formed in an annular shape. The connection end 44 a of the coil 44 is drawn into the control chamber 17 and connected to the control board 5. The stator 41 is provided integrally with the motor case 13 by insert molding, and a part of the stator 41 is embedded in the cylindrical portion 13 c of the motor case 13. Further, the stator 41 is disposed on the other end side in the axial direction with respect to the suction flow path 21.

  On the other hand, the rotor 42 is configured to prevent the rotor core 46 fixed to the rotating shaft 45, a plurality (eight in this embodiment) of permanent magnets 47 fixed to the outer periphery of the rotor core 46, and scattering of the permanent magnets 47. The holder 48 is provided. The rotary shaft 45 is rotatably supported by bearings 49a and 49b provided on the bottom portion 11a of the pump case 11 and the bottom portion 13a of the motor case 13, and one end portion thereof (the right end portion in FIG. 1) is inside the pump chamber 15. Protruding. An inner gear 32 of the pump 3 is connected to one end of the rotating shaft 45 so as to be integrally rotatable.

  As shown in FIGS. 2 and 3, the rotor core 46 is made of a magnetic material and is formed in a cylindrical shape. The permanent magnet 47 is formed in a plate shape curved in an arc shape when viewed in the axial direction. Further, the permanent magnets 47 are arranged at equiangular intervals on the outer peripheral surface of the rotor core 46 so that different polarities (N poles and S poles) are alternately arranged in the circumferential direction. The cage 48 includes a plurality (eight in this embodiment) of arms 51 arranged between adjacent permanent magnets 47. Each arm 51 is formed in a rod shape extending in the axial direction of the rotor 42, and both ends of the arm 51 are connected by an annular ring body 52 disposed on the shaft end surface of the rotor core 46. Note that the cage 48 of the present embodiment is made of a resin material and is provided integrally with the rotor core 46 by insert molding.

  As shown in FIG. 2, each arm 51 includes a main body 53 that extends radially outward from the outer peripheral surface of the rotor core 46, and a permanent magnet that protrudes from the radially outer end of the main body 53 to both sides in the circumferential direction. Claw portions 54 and 55 for holding 47. The claw portions 54, 55 are formed so as to protrude radially outward from the outer surface of the permanent magnet 47, and hold the permanent magnet 47 so as to be sandwiched between the rotor core 46. The claw portions 54 and 55 prevent the permanent magnet 47 from being scattered by the centrifugal force accompanying the rotation of the rotor 42. Note that a locking portion (not shown) that slightly protrudes on both sides in the circumferential direction is formed at one axial end of the main body 53, and the permanent magnet 47 inserted between the arms 51 from the other axial end. Is positioned.

  In the electric pump device 1 configured as described above, when the driving power is supplied from the control board 5 to the motor 4 and the rotor 42 rotates in one direction, the inner gear 32 rotates and the pump 3 is driven. As a result, the hydraulic oil 22 is sucked into the motor chamber 16 from the oil reservoir (not shown) via the suction passage 21 and further sucked into the pump chamber 15 via the communication hole 23. Then, the hydraulic oil 22 is discharged from the pump chamber 15 to the transmission or the like via the discharge passage 24. As described above, in the electric pump device 1, the hydraulic oil 22 is sucked into the pump chamber 15 through the motor chamber 16, so that the motor 4 and the control board 5 are cooled by the hydraulic oil 22.

Next, a configuration for circulating hydraulic oil in the motor chamber in the electric pump device of the present embodiment will be described.
As shown in FIG. 3, the claw portion 54 arranged on the front side in the rotational direction of the rotor 42 is larger in the axial one end side than the other axial end side in the radial direction view of the rotor 42 and protrudes forward in the rotational direction. It is formed to do. Specifically, the claw portion 54 is formed so that the protruding amount gradually increases from the other axial end side toward the one axial end side. As shown in FIG. 2, the circumferential end surface 54 a of the claw portion 54 is formed in a linear shape extending in parallel along the radial direction when the rotor 42 is viewed in the axial direction. That is, the circumferential end surface 54a is formed so as to be orthogonal to the rotational direction of the rotor 42 as viewed in the axial direction. Further, as shown in FIG. 3, the circumferential end surface 54 a is formed in a linear shape inclined at a constant angle with respect to the axial direction when the rotor 42 is viewed in the radial direction. The circumferential end surface 55a of the claw portion 55 disposed on the rear side in the rotational direction of the rotor 42 is formed in a straight line extending in parallel along the radial direction as viewed in the axial direction of the rotor 42, and It is formed in a straight line extending in parallel along the axial direction in the radial direction view. As shown in FIGS. 1 and 2, the rotor core 46 is formed with a plurality of (four in this embodiment) flow holes 57 penetrating in the axial direction. The flow hole 57 is formed so as to be inclined linearly so that the opening 57a on one end side in the axial direction of the rotor core 46 is located on the radially outer side with respect to the opening 57b on the other end side in the axial direction.

Next, the operation of the electric pump device of this embodiment will be described.
When driving power is supplied to the coil 44 of the stator 41 and the rotor 42 rotates, the hydraulic oil 22 hits the circumferential end face 54 a of the claw portion 54 disposed on the front side in the rotation direction of each arm 51. As shown in FIG. 4, the claw portion 54 is formed so that the one end side in the axial direction protrudes larger than the other end side in the axial direction, so that the hydraulic oil 22 that hits the circumferential end face 54 a is It flows from one axial end to the other axial end. Since the rotor core 46 is formed with the flow hole 57 penetrating in the axial direction, the hydraulic oil 22 flowing to the other end side in the axial direction by the claw 54 as described above passes through the flow hole 57. It flows to one end side in the axial direction. Here, the circulation hole 57 of the present embodiment is inclined linearly so that the opening 57a on one axial end side is located radially outside the opening 57b on the other axial end side. The hydraulic oil 22 in the hole 57 is sent from the other end side in the axial direction to one end side in the axial direction by the centrifugal force accompanying the rotation of the rotor 42. As a result, the hydraulic oil 22 circulates in the motor chamber 16, and the flow of the hydraulic oil 22 is less likely to stagnate in the motor chamber 16.

As described above, according to the present embodiment, the following effects can be obtained.
(1) By forming the claw portion 54 arranged on the front side in the rotational direction of the rotor 42 so that the one end side in the axial direction protrudes larger than the other end side in the axial direction, the hydraulic oil 22 is moved from one end side in the axial direction. Since the flow of the hydraulic oil 22 is less likely to stagnate in the motor chamber 16 due to the flow toward the other end in the axial direction, the cooling performance of the motor 4 can be improved.

  (2) Since the flow hole 57 penetrating in the axial direction is formed in the rotor core 46, the hydraulic oil 22 is easily circulated in the motor chamber 16, and the flow of the hydraulic oil 22 can be made more difficult to stagnate.

  (3) The circulation hole 57 is formed so as to be inclined so that the opening 57a on one axial end side is located radially outside the opening 57b on the other axial end side, and the hydraulic oil 22 in the circulation hole 57 is subjected to centrifugal force. Therefore, the hydraulic oil 22 is more easily circulated in the motor chamber 16 and the flow of the hydraulic oil 22 can be made more difficult to stagnate.

  (4) The pump chamber 15 is provided on one axial end side of the motor chamber 16, the control chamber 17 is provided on the other axial end side of the motor chamber 16, and the suction passage 21 is connected to the pump chamber in the cylinder portion 13 c of the motor case 13. It was formed at a position close to 15.

  Here, in order to more reliably prevent the hydraulic oil 22 from entering the control chamber 17, it is preferable to provide an interval greater than or equal to a predetermined interval between the control chamber 17 and the suction channel 21. In the case where 21 is formed at a position near the control chamber 17, the housing 2 is easily increased in size. For this reason, it is possible to suppress the increase in size of the housing 2 by forming the suction channel 21 at a position near the pump chamber 15. In this case, the suction channel 21 and the communication hole 23 are provided in the motor chamber 16. Therefore, the hydraulic oil 22 is difficult to flow to the other axial end side (control chamber 17 side). In this respect, in this embodiment, since the hydraulic oil 22 is caused to flow to the other axial end side (the control chamber 17 side) by the claw portion 54, the cooling performance is effectively improved while suppressing the enlargement of the housing 2. be able to.

  (5) Since the protruding amount of the claw portion 54 is formed so as to gradually increase from the other axial end side toward the one axial end side, the hydraulic oil 22 that has hit the claw portion 54 is axially moved from the axial one end side. It can flow suitably to the other end side.

In addition, the said embodiment can also be implemented in the following aspects which changed this suitably.
In the above embodiment, the circumferential end surface 54a of the claw portion 54 is formed in a linear shape inclined at a constant angle with respect to the axial direction when viewed in the radial direction of the rotor 42, and the claw portion 54 is formed from the other axial end side. The amount of protrusion gradually increased toward one end in the axial direction. However, the present invention is not limited to this. For example, as shown in FIG. 5A, both ends in the axial direction of the circumferential end surface 54a may be rounded. Further, for example, as shown in FIG. 5 (b), the circumferential end face 54a has an arc shape that gradually increases as it goes toward one end in the axial direction. For example, as shown in FIG. 5 (c), the circumferential direction Alternatively, the end surface 55a may be formed in an arc shape that gradually decreases as the inclination angle approaches one end side in the axial direction. Further, as shown in FIG. 5D, for example, the circumferential end face 55a may have an S-shape that gradually increases as the inclination angle toward the one end side in the axial direction gradually decreases and then gradually decreases. Furthermore, the projection amount of the claw portion 54 does not have to gradually increase from the other axial end side to the one axial end side. For example, as shown in FIG. You may make it become large in steps. Note that the circumferential end surface 54a may be non-parallel to the radial direction when the rotor 42 is viewed in the axial direction, that is, the circumferential end surface 54a may not be orthogonal to the rotational direction. In short, the shape of the claw portion 54 can be appropriately changed as long as the claw portion 54 protrudes larger on the one end side in the axial direction than on the other end side in the axial direction.

The claw portion 55 may be formed so that the one end side in the axial direction protrudes larger than the other end side in the axial direction, like the claw portion 54.
In the above embodiment, the suction flow path 21 may be formed at a position near the control chamber 17 in the cylindrical portion 13c.

In the above embodiment, the control chamber 17 may be provided on one axial end side of the motor chamber 16, and the pump chamber 15 and the suction flow path 21 may be provided on the other axial end side of the motor chamber 16.
In the above embodiment, the flow hole 57 is formed so as to be inclined linearly. However, the present invention is not limited to this, and the opening 57a on one end side in the axial direction is located on the radially outer side than the opening 57b on the other end side in the axial direction. For example, the flow hole 57 may be formed in a curved shape. Further, the flow hole 57 may be formed so that the distance along the radial direction from the center of the rotor core 46 to the openings 57a and 57b is equal. For example, the flow hole 57 is formed in a straight line parallel to the axial direction. Also good. Furthermore, the number of flow holes 57 may be one and can be changed as appropriate. It is not necessary to form the flow hole 57 in the rotor core 46.

  In the above embodiment, the cage 48 is provided integrally with the rotor core 46 by insert molding. However, for example, the cage 48 may be separately formed by injection molding and assembled to the rotor core 46.

In the above embodiment, the control board 5 may not be integrally housed in the housing 2 but may be disposed outside the housing 2.
In the above embodiment, another pump such as a vane pump may be employed for the pump 3, and another motor other than the brushless motor may be employed for the motor 4.

  In the above embodiment, the present invention is applied to the electric pump device 1 for securing the hydraulic pressure supply to the transmission or the like at the time of idling stop. May be.

Next, technical ideas that can be grasped from the above-described embodiment and other examples will be described below together with their effects.
(A) In the electric pump device according to any one of claims 1 to 4, the protrusion amount of the claw portion is gradually increased from the other axial end side toward the one axial end side. Electric pump device. According to the above configuration, the hydraulic oil that has hit the claw portion can be suitably flowed from one axial end to the other axial end.

  DESCRIPTION OF SYMBOLS 1 ... Electric pump apparatus, 2 ... Housing, 3 ... Pump, 4 ... Motor, 5 ... Control board, 11 ... Pump case, 12 ... Pump plate, 13 ... Motor case, 14 ... Cover, 15 ... Pump chamber, 16 ... Motor Chamber, 17 ... control chamber, 21 ... suction passage, 22 ... hydraulic oil, 23 ... communication hole, 24 ... discharge passage, 42 ... rotor, 45 ... rotating shaft, 46 ... rotor core, 47 ... permanent magnet, 48 ... holding 51, arm, 52 ... ring body, 53 ... main body, 54, 55 ... claw, 54a, 55a ... circumferential end face, 57 ... flow hole, 57a, 57b ... opening.

Claims (4)

A pump that generates hydraulic pressure, a motor that drives the pump, and a housing that integrally accommodates the pump and the motor,
The housing is formed with a suction flow path that opens to a motor chamber that houses the motor and a discharge flow path that opens to a pump chamber that houses the pump, and communicates the motor chamber and the pump chamber. A communication hole is formed,
The hydraulic oil is sucked into the pump chamber from the suction passage through the motor chamber and the communication hole, and discharged from the discharge passage when the rotor of the motor rotates and the pump is driven. In the electric pump device
The rotor includes a plurality of permanent magnets disposed on an outer periphery of a rotor core, and a cage having a plurality of arms disposed between the adjacent permanent magnets,
The arm is formed with a claw portion that protrudes on both sides in the circumferential direction and holds the permanent magnet,
The electric pump device, wherein the claw portion disposed on the front side in the rotation direction of the rotor is formed so that one end side in the axial direction protrudes larger than the other end side in the axial direction. The electric pump device according to claim 1,
An electric pump device characterized in that a flow hole penetrating in the axial direction is formed in the rotor core. In the electric pump device according to claim 2,
The flow hole is formed so that the opening on one end side in the axial direction is positioned radially outside the opening on the other end side in the axial direction. In the electric pump device according to any one of claims 1 to 3,
The housing is provided with a control chamber partitioned in a state in which hydraulic oil is prevented from entering,
The control room contains a control device for controlling the operation of the motor,
The pump chamber is provided on one axial end side of the motor chamber, and the control chamber is provided on the other axial end side of the motor chamber,
The electric pump device according to claim 1, wherein the suction passage is formed at a position near the pump chamber in the housing.