JPS6365832B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pump device driven by a motor, and particularly to a pump device suitably used as a fuel pump for automobiles, motorcycles, and the like.

Conventionally, a typical pump device uses a so-called brush motor to drive a rotary pump such as a vane pump. However, in such conventional devices, in order to connect the rotary pump to the output shaft of the motor, the motor and rotary pump must be installed in parallel in the axial direction of the output shaft, which inevitably increases the size of the entire pump device. There is a problem with doing so.

The present invention eliminates such problems and allows the effective diameter of the motor rotor to be set significantly larger than the outer diameter of the pump rotor without creating a large dead space inside the permanent magnet of the motor rotor in the radial direction. It is an object of the present invention to provide a compact pump device that can secure sufficient driving torque.

In order to achieve the above object, the pump device of the present invention is a pump device in which a rotary pump and a brushless motor for driving the rotary pump are arranged concentrically with each other, and the rotary pump has a suction path and a discharge path. The brushless motor includes a housing forming a pump chamber in which the pump chambers are communicated with each other, a rotating shaft rotatably supported by the housing, and a rotor fixed to the rotating shaft within the pump chamber.
A stator fixed to the housing so as to surround the rotor and having a plurality of coils wound thereon at intervals in the circumferential direction, a ring-shaped permanent magnet surrounding the stator, and the rotating shaft are integrated. a rotor having a plate-shaped connecting portion disposed adjacent to one side of the stator so as to be connected to each other; and a drive circuit that distributes a drive current to each of the coils according to the magnetic pole position of the permanent magnet. It is characterized by

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In FIGS. 1 and 2, this pump device 1 includes a rotary pump 2 and a brushless motor 3.
The brushless motor 3 is arranged to surround the rotary pump 2.

The rotary pump 2 includes a housing 5 forming a pump chamber 4 , a rotating shaft 6 rotatably supported by the housing 5 , and a rotor 7 fixed to the rotating shaft 6 within the pump chamber 4 . The housing 5 is formed by closing the open end of a bottomed cylindrical body 8 with eccentric outer and inner circumferences with a lid 9, and a flange 10 extending radially outward in the middle of the bottomed cylindrical body 8. Integrated. The pump chamber 4 is defined by the lid 9 and the inner surface of the bottomed cylindrical body 8. One end of the rotating shaft 6 is rotatably supported by the bottom 8a of the bottomed cylindrical body 8 via a bearing 11, and the other end is supported by the lid 9 via a bearing 12 and projects outward. Moreover, the axis of the rotating shaft 6 is set concentrically with the outer periphery of the bottomed cylindrical body 8, and is eccentric to the pump chamber 4.

The bottomed cylindrical body 8 has a suction passage 13 and a discharge passage 1.
4 are bored respectively, and the suction passage 13
The discharge passage 14 is communicated with the inner surface of the pump chamber 4 at a position shifted in the circumferential direction. Further, a suction pipe section 15 and a discharge pipe line 16 that communicate with the suction passage 13 and the discharge passage 14 respectively are integrally provided in the bottomed cylindrical body 8, and a connecting portion is provided in the middle of the suction pipe section 15 and the discharge pipe section 16. 17. This connecting pipe 17
is equipped with a relief valve 18 that only allows fluid to flow from the discharge pipe section 16 to the suction pipe section 15.

In the pump chamber 4, a ring-shaped rotor 7 is fixed to the rotating shaft 6, and the rotor 7 has a plurality of vanes 19 (four shown) biased in a direction protruding outward. It will be installed. each vane 1
The pump 9 rotates while slidingly contacting the inner surface of the pump chamber 4 in accordance with the rotation of the rotating shaft 6 and the rotor 7, whereby the fluid sucked from the suction passage 13 is discharged from the discharge passage 14.

The brushless motor 3 is fixed around a housing 5 concentrically with a rotating shaft 6, and has a plurality of phase (two-phase, four-pole in this embodiment) coils 2 spaced apart in the circumferential direction.
A rotor 23 has a permanent magnet 22 surrounding the stator 21 and is fixed to the rotating shaft 6. A drive circuit 24 that distributes drive current is provided.

The stator 21 is closely fixed to the outer surface of the bottomed cylindrical body 8 in the housing 5 . The rotor 23 is
It is formed into a bottomed cylindrical shape as a whole from a thin plate material, that is, it has a cylindrical part 23b concentrically surrounding the stator 21, and a stator integrally connected to one end of the cylindrical part 23b. 21 and a connecting portion 23a adjacent to one side of the connecting portion 23a.
The center part of a is fixed to the protruding end of the rotary shaft 6 with a synthetic resin washer 25 interposed between it and the bearing 12 of the lid 9. Further, the permanent magnet 22 is formed in a ring shape so as to surround the stator 21, and is integrally fitted onto the inner peripheral surface of the cylindrical portion 23b. Moreover, the center position m of the permanent magnet 22 along the axial direction and the center position l of the stator 21 along the axial direction are shifted from each other. Specifically, the center position m of the permanent magnet 22 is located on the outer side along the axis of the rotating shaft 6, that is, the first
The relative positions of the permanent magnet 22 and the stator 21 are set so that they are located on the upper side of the figure.

The drive circuit 24 is provided on a circuit board 26 installed in a ring shape on the surface of the flange 10 of the bottomed cylindrical body 8 on the side opposite to the rotor 23 . This drive circuit 24 includes means for detecting the magnetic pole position of the permanent magnet 22, such as a Hall element (not shown), and this Hall element is embedded in the collar 10.

A ring-shaped cover 27 is attached to one axial side of the collar 10 to cover the drive circuit 24, and this cover 27 is attached to a deep-dish-shaped cover 28 that covers the rotor 23.
By caulking the outer peripheral edge of the cover 28, the cover 28 and the cover 28 are integrally fixed to the flange 10.

A screw hole 29 is formed in the bottom 8a of the bottomed cylindrical body 8, and by screwing a bolt into the screw hole 29, the pump device 1 is fixed to an appropriate position such as the body of a car. .

Next, the operation of this embodiment will be explained. By sequentially exciting each coil 20 in the circumferential direction by the drive circuit 24, rotational force is applied to the rotor 23, and the rotating shaft 6 is integrally moved with the rotor 23. By rotating, the rotary pump 2 performs a pumping operation. As a result, fluid such as fuel is sucked into the pump chamber 4 from the suction pipe section 15 and the discharge pipe section 16
It is continuously discharged from

In such a pump device 1, since the rotary pump 2 is arranged so as to be surrounded by the brushless motor 3, the thickness of the pump device 1 along the axis of the rotary shaft 6 can be made as thin as possible to reduce the size. becomes possible. Moreover, since the diameter d2 of the rotor 23 is set larger than the diameter d1 of the rotor 7,
The operating torque for the rotor 7 becomes large, and both the discharge flow rate and the discharge pressure can be set large compared to the size of the rotary pump 2. In addition, since the rotary pump 2 is driven by a brushless motor 3,
It is possible to prevent torque down, deterioration of durability, and adverse effects on electrical equipment due to sparks, which occur when conventional brush motors are used.

Furthermore, the center position m of the permanent magnet 22 is
The rotary shaft 6 is located on the outer side of the rotation shaft 6 than the center position l of the rotary shaft 6 . On the other hand, since the permanent magnet 22 is biased so as to be magnetically attracted to the stator 21 side, the rotor 23 is biased inward in the axial direction of the rotating shaft 6. Minor movement in the axial direction is prevented. As a result, the fine movement of the rotor 7 caused by the fine movement of the rotor 23 is prevented, and the negative effects such as pulsating discharge caused by the fine movement of the rotor 7 can be prevented.

As another embodiment of the present invention, roller vanes may be used instead of the blade-like vanes 19. Further, as the rotary pump, a trochoid pump may be used instead of the vane pump shown in the above embodiment. In that case, an inner rotor provided with external teeth is fixed to the rotating shaft 6, and an inner rotor that meshes with the external teeth is fixed to the rotating shaft 6. The outer rotor with teeth is a bottomed cylindrical body 8
is fitted in.

Furthermore, the pump device of the present invention can be widely implemented not only as a fuel pump but also as a pump for pumping other fluids.

As described above, the device of the present invention is a pump device in which a rotary pump and a brushless motor for driving the rotary pump are arranged concentrically with each other, and the rotary pump is a pump with a suction passage and a discharge passage communicating with each other. The brushless motor includes a housing forming a chamber, a rotating shaft rotatably supported by the housing, and a rotor fixed to the rotating shaft within the pump chamber, and the brushless motor is mounted on the housing so as to surround the rotor. In order to integrally connect a fixed stator with coils of multiple phases wound around the stator at intervals in the circumferential direction, a ring-shaped permanent magnet surrounding the stator, and the rotating shaft, The rotor is provided with a rotor having a plate-shaped connecting portion arranged adjacent to the side, and a drive circuit that distributes a drive current to each of the coils according to the magnetic pole position of the permanent magnet. The rotary pump can be placed on the radially outer side, and the permanent magnets of the brushless motor's stator and rotor can be arranged concentrically on the radially outer side of the rotary pump, and these parts can be overlapped around the axis of rotation. This is extremely advantageous in downsizing the entire pump device in the direction of the rotation axis.
Moreover, since the permanent magnets of the motor rotor surround the pump rotor via the stator, the effective diameter of the motor rotor can be set to be significantly larger than the outer diameter of the pump rotor, and the size of the rotary pump can therefore be reduced. Compared to the above, it is possible to secure sufficient pump driving force of the motor, which is advantageous in increasing the discharge flow rate and discharge thickness of the motor, and in addition, as mentioned above, the effective diameter of the motor rotor can be increased. Since the space inside the rotor permanent magnet in the radial direction is effectively used as the installation space for the motor stator and rotary pump, there is no risk of creating a large dead space there. In addition, since the connecting portion connecting the permanent magnets of the motor rotor and the rotating shaft is formed in a plate shape and is arranged adjacent to one side of the motor stator, the connecting portion connects the permanent magnet of the motor rotor and the rotating shaft. Although the motors are arranged in parallel, the increase in dimensions of the motors in the same direction can be kept to a small extent.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal sectional side view, and FIG. 2 is a sectional view taken along the line -- in FIG. 1. 1... Pump device, 2... Rotary pump, 3...
Brushless motor, 4...pump chamber, 5...housing, 6...rotating shaft, 7...rotor, 13...
Suction path, 14...Discharge path, 20...Coil, 21
... Stator, 22 ... Permanent magnet, 23 ... Rotor, 23a ... Connection section, 24 ... Drive circuit.

Claims (1)

[Scope of Claims] 1. A pump device in which a rotary pump 2 and a brushless motor 3 for driving the same are disposed concentrically with each other, and the rotary pump 2 has a suction passage 13 and a discharge passage 14 that are in communication with each other. a housing 5 forming a pump chamber 4, a rotating shaft 6 rotatably supported by the housing 5, and a rotating shaft 6 forming a pump chamber 4;
The brushless motor 3 is fixed to the housing 5 so as to surround the rotor 7, and a plurality of phase coils 20 are wound around the rotor 7 at intervals in the circumferential direction. A plate-shaped connecting portion is disposed adjacent to one side of the stator 21 to integrally connect the stator 21 formed by the stator 21, the ring-shaped permanent magnet 22 surrounding the stator 21, and the rotating shaft 6. 23a, and each coil 2 according to the magnetic pole position of the permanent magnet 22.
1. A pump device comprising: a drive circuit 24 that distributes a drive current to zero. 2. The pump device according to claim 1, wherein the stator 21 and the permanent magnet 22 are arranged such that their axial center positions are shifted from each other.