JPH09317683A - Fluid pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid pump which can be miniaturized in the axial direction. SOLUTION: A stator core 2 is fixed on a motor housing 1, and a bearing 12, a rotor base 13, and permanent magnet 15a-15f are arranged inward in the stator core 2. An impeller 16 is integrally formed on one end part of the rotor base 13. Stator (12, 13, 15a-15f) are partitioned from fluid by a can 17 made of a thin plate. A recessed part 14 extending in the axial direction is formed on the other end surface of the rotor base 13, an inside cylinder part 21 of the can 17 extends in the inside of the recessed part 14 and it is sealed by an O ring between the inside cylinder part 21 and a shaft fixing part 10 of an end frame 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pump using an electric motor.

[0002]

2. Description of the Related Art Conventionally, a water pump using an electric motor is known (for example, Japanese Patent Laid-Open No. 2-91).
498). Explaining this type of pump with reference to FIG. 7, a stator core 42 having a coil 41 wound is fixed to an inner peripheral surface of a cylindrical motor housing 40, and a rotor 44 having a permanent magnet 43 is arranged inside thereof. The impeller 45 is fixed to one end of the rotor 44, and the stator side is separated from the fluid by a cylindrical thin can (partition plate) 46. That is, the sealing projection 47 a extending from the end frame 47 projects into one opening of the cylindrical can 46, and the O-ring 48 is provided between the outer peripheral surface of the sealing projection 47 a and the inner peripheral surface of the can 46.
Sealed by The other opening of the cylindrical can 46 is sealed by an O-ring 49.

[0003]

However, in the structure in which the inner circumference of the cylindrical can 46 is sealed by the O-rings 48 and 49, a space for sealing is required in the axial direction of the motor, and the size of the space increases. .

Therefore, an object of the present invention is to provide a fluid pump which can be miniaturized in the axial direction.

[0005]

According to a first aspect of the present invention, there is provided a fluid pump in which an impeller is provided at one end of a rotor base of an electric motor, and a stator made of a thin plate separates a stator from a fluid. While providing a recess extending in the axial direction on the other end surface of the rotor base,
The gist of the present invention is a fluid pump in which the can is extended in the concave portion and sealed between the extended portion of the can and the fixed side.

According to a second aspect of the present invention, a cylindrical motor housing is fixed in the motor housing,
A stator core around which a coil is wound, a rotor base rotatably disposed in the motor housing, and a permanent magnet fixed to an outer peripheral surface facing the stator core, an impeller provided at one end of the rotor base, A pump casing that is connected to the motor housing and houses the impeller; a recess that is provided on an end surface of the rotor base on the side opposite to the impeller and that extends in the axial direction; and a thin plate that is sandwiched between the motor housing and the pump casing. And a fluid partitioning can extending through the inner peripheral surface of the stator core to the inside of the recess, and a seal member provided between the inner peripheral surface of the can extending portion and the fixed side in the recess. A fluid pump provided with is the gist. (Operation) According to the inventions of claims 1 and 2, the can is sealed in the recess extending in the axial direction at the end surface of the rotor base. That is, the can is sealed without increasing the total length of the rotor base for the can seal. In other words, the total length of the rotor base is shortened by the length required for the conventional sealing (shown by L1 in FIG. 7).

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a vertical sectional view of an electric motor type water pump according to the present embodiment. FIG. 2 shows a side view of the water pump. Further, FIG. 3 shows a sectional view of the motor portion in FIG.

The water pump in the present embodiment is an electric water pump mounted on an automobile. or,
This water pump is a so-called canned pump in which fluid is partitioned from the stator (stator) by a can (partition plate) 17. Furthermore, a brushless motor is used as the electric motor.

The details will be described below. As shown in FIG. 1, the resin motor housing 1 includes a cylindrical stator core support portion 1a and a flange portion 1b extending outward from one end (left end) of the stator core support portion 1a. A stator core 2 is fixed to the inner peripheral surface of the stator core support portion 1a of the motor housing 1. The stator core 2 has a cylindrical shape and is formed by stacking a large number of plate materials made of a magnetic material. A coil (winding) 3 is wound around the stator core 2. One opening (right side opening) in the stator core supporting portion 1a of the motor housing 1
Is provided with a disk-shaped end frame 4,
A resin pump casing 5 is fastened and fixed to the flange portion 1b of the motor housing 1 with screws 6. The pump casing 5 is provided with an inlet pipe 7 and an outlet pipe 8.
A cylindrical shaft fixing portion (shaft supporting portion) 9 is provided in the pump casing 5. A cylindrical shaft fixing portion (shaft supporting portion) 10 is provided at the center of the end frame 4 so as to project. A shaft 11 is fixed between the shaft fixing portion 9 and the shaft fixing portion 10 in the motor housing 1 and the pump casing 5.

A cylindrical bearing 12 is rotatably arranged on the outer periphery of the shaft 11, and a rotor base 13 is fixed to the bearing 12. A recess 14 extending in the axial direction is formed on the right end surface of the rotor base 13 in FIG. The shaft fixing portion 10 of the end frame 4 is located in the recess 14. Permanent magnets 15a to 15f are fixed to the outer peripheral portion of the rotor base 13. That is, each of the permanent magnets 15a to 15f extends in the axial direction with respect to the cylindrical magnetic body, and is configured by alternately magnetizing the N and S poles every 60 °. The permanent magnets 15a-15
f may be configured by assembling six bar-shaped magnets.

The permanent magnets 15a to 15f face the stator core 2. Also, the rotor base 1 in FIG.
An impeller 16 is integrally provided at the left end of 3, and the impeller 16 is housed in the pump casing 5. The rotation of the impeller 16 allows the engine cooling water to be sucked from the inlet pipe 7 and discharged from the outlet pipe 8.

In this embodiment, the permanent magnets 15a to 15a are used.
The rotor is composed of f, the rotor base 13, and the bearing 12, and the stator (stator) is composed of the stator core 2 and the coil 3.

Here, the rotor permanent magnets 15a to 15f are used.
The positional relationship between the stator core 2 and the stator core 2 will be described. Let Lc1 be the center position (rotor side magnetic center) of the rotor permanent magnets 15a to 15f in the axial direction of the rotor of FIG. 1, and let Lc2 be the center position of the stator core 2 (stator side magnetic center). Are displaced by a predetermined distance ΔL. More specifically, the center position Lc1 of the permanent magnets 15a to 15f is a position separated from the center position Lc2 of the stator core 2 by ΔL on the pump casing 5 side. Therefore, a rightward magnetic force in FIG. 1 acts on the rotor permanent magnets 15a to 15f (rotor). In this way, the rotor permanent magnets 15a to 15f and the stator core 2 are arranged in a staggered manner in the axial direction of the rotor, and the magnetic force between the two urges the rotor toward the end frame 4 side in the axial direction.

Motor housing 1 and pump casing 5
A can (partition plate) 17 made of a thin plate is sandwiched between and, and the can 17 separates the stator (stator) from the fluid.

The can 17 will be described in more detail. As the thin plate, a stainless steel plate (SUS) having a thickness of about 0.2 to 0.5 mm is used. Other materials such as brass, aluminum and ceramics may be used as long as they are non-magnetic materials. As shown in FIG. 1, the can 17 includes a cylindrical portion 18,
A disc portion 19 extending outward from one end (left end) of the cylindrical portion 18
4, a disc portion 20 that extends inward from the other end (right end) of the cylindrical portion 18, an inner cylinder portion 21 that extends from the inner peripheral surface of the disc portion 20 in the axial direction of the rotor, and an inner cylinder. The disk portion 22 extends inward from one end (left end) of the portion 21. FIG.
As shown in FIG. 3, the disk portion 19 of the can 17 is arranged between the flange portion 1b of the motor housing 1 and the pump casing 5, and the cylindrical portion 18 is formed on the inner peripheral surface of the stator core support portion 1a of the motor housing 1 and the stator core 2. It is placed in close contact with the inner peripheral surface of the. Further, as shown in FIG. 4, the inner cylinder portion 21 of the can 17 is arranged in a state of being in close contact with the outer peripheral surface of the shaft fixing portion 10 of the end frame 4 through the disc portion 20, and the disc portion 22 is arranged in the shaft fixing portion. 10
Is arranged in close contact with the axial end face of the.

As described above, in the can 17, the disc portion 20, the inner cylinder portion 21 and the disc portion 22 are extended from the cylindrical portion 18, and the inner cylinder portion 21 is arranged in the recess 14.
As shown in FIG. 1, an O-ring 23 as a seal member is provided between the disc portion 19 of the can 17 and the pump casing 5.
However, as shown in FIG. 4, an O-ring 24 as a seal member is arranged between the inner peripheral surface of the inner cylindrical portion 21 of the can 17 and the outer peripheral surface of the shaft fixing portion 10 of the end frame 4. There is. As shown in FIG. 4, the disc portion 22 of the can 17 is
Is caused by the biasing force of the bearing 12 in the thrust direction.
The end surface of the bearing 12 slides on the surface of the disk portion 22 of the can 17 as the bearing 12 rotates, and functions as a thrust bearing material. That is, the washer is unnecessary by extending the disk portion 22 from the can 17 instead of the washer as the thrust bearing material which is generally used.

On the other hand, as shown in FIG. 1, a substrate 25 is arranged on the outer peripheral surface of the end frame 4 so as to be in surface contact therewith. That is, the substrate 25 is arranged in the direction (radial direction) orthogonal to the axial direction of the rotor. A printed board such as a glass / epoxy board is used as the board 25.
A magnetic detection element 26 for detecting the rotor rotational position is attached to the. The magnetic detection element 26 is in close contact with the disk portion 20 of the can 17, and faces the end faces of the rotor permanent magnets 15a to 15f in the axial direction. A conductive pattern is formed on the substrate 25, and the rotor rotational position detecting magnetic detection element 26 is electrically connected to an external motor driver (driving circuit) through the conductive pattern. The motor driver (driving circuit) may be formed on the substrate 25.

Further, as shown in FIG. 1, the end frame 4
A protective cap 27 that covers the substrate 25 is attached to the substrate, and the substrate 25 is protected by the protective cap 27. Next, the operation of the seal structure using the O-ring 24 in the inner cylindrical portion 21 of the can 17 of the canned pump thus configured will be described.

With respect to the recess 14 extending in the axial direction at one end of the rotor base 13, a can 17 corresponding to the recess 14 is provided.
The inner cylindrical portion 21 is disposed, and the O-ring 24 that contacts the inner peripheral surface of the inner cylindrical portion 21 is disposed, and the O-ring 24 seals.

In the conventional seal structure shown in FIG. 7,
Since the inner circumference of the cylindrical can 46 is sealed by the O-ring 48, a space L1 for sealing is required in the axial direction.

On the other hand, in this embodiment, the anti-impeller side seal portion of the can 17 is a recess formed in the end surface of the rotor base 13, so that a space for sealing can be eliminated in the axial direction (the space corresponding to the space). The axial dimension can be shortened by the length L1), and the size of the pump can be reduced.

As described above, this embodiment has the following features. (A) The recess 14 extending in the axial direction is provided on the other end surface of the rotor base 13, and the inner tubular portion 21 of the can 17 is provided in the recess 14 to extend the inner tubular portion 21 and the caft fixing portion 10.
It was sealed between (fixed side). Therefore, without increasing the total length of the rotor base 13 for the can seal,
The can 17 is sealed, and the total length of the rotor base is shortened by the length (L1 in FIG. 7) required for conventional sealing. As a result, it is possible to reduce the size in the axial direction.

Although the brushless motor is used as the electric motor, an induction motor or a synchronous motor may be used.
In addition to the modes described above, the following modes may be used.

As a sealing structure on the outer peripheral side of the can 17 (on the side of the disc portion 19), as shown in FIG. 5, as shown in FIG. 5, the outer peripheral side of the disc portion 19 of the can 17 is bent to form a cylinder. The portion 30 may be formed and the outer peripheral surface of the cylindrical portion 30 may be sealed with the O-ring 23.

As another form, the pump having a structure in which the shaft 11 is fixed in FIG. 1 may be applied to a pump having a structure in which the shaft 31 rotates as shown in FIG. In FIG. 6, the shaft support 32 of the end frame 4 is provided in the recess 14 of the rotor base 13.
Is arranged, and the shaft 31 is rotatably supported via a bearing member 33. An O-ring 34 as a seal member is interposed between the outer peripheral surface of the bearing member 33 and the inner cylindrical portion 21 of the can 17.

[0026]

As described above in detail, according to the present invention,
It has the excellent effect that the total length of the rotor base can be shortened by the length required for conventional sealing and the axial miniaturization can be achieved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an electric water pump according to an embodiment.

FIG. 2 is a side view of the water pump.

FIG. 3 is a sectional view of a motor portion of a water pump.

FIG. 4 is a partially enlarged cross-sectional view of a water pump.

FIG. 5 is a cross-sectional view of an electric water pump according to another embodiment.

FIG. 6 is a partially enlarged cross-sectional view of an electric water pump according to another embodiment.

FIG. 7 is a cross-sectional view of an electric water pump for explaining a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Motor housing, 2 ... Stator core which comprises a stator, 3 ... Coil which comprises a stator, 5 ... Pump casing, shaft fixed part (fixed side), 12 ... Bearing which comprises a rotor, 13 ... Rotor base which comprises a rotor ,
14 ... Recessed portions, 15a to 15f ... Rotor permanent magnets constituting the rotor, 16 ... Impeller, 17 ... Can, 20 ... Disk portion as extended portion, 21 ... Inner cylindrical portion as extended portion, 2
4 ... O-ring as seal member

Claims (2)

[Claims] 1. A fluid pump in which an impeller is provided at one end of a rotor base of an electric motor, and a stator made of a thin plate separates the stator from the fluid, and a recess extending in the axial direction is provided at the other end surface of the rotor base. A fluid pump, wherein the fluid pump is provided, and the can is extended in the recess to seal between an extended portion of the can and a fixed side. 2. A cylindrical motor housing, a stator core fixed in the motor housing and having a coil wound around it, a rotor core rotatably disposed in the motor housing, and an outer peripheral surface facing the stator core. A rotor base to which a magnet is fixed, an impeller provided at one end of the rotor base, a pump casing that is coupled to the motor housing and houses the impeller, and a shaft provided on an end surface of the rotor base on the side opposite to the impeller. A recess extending in the direction, a thin plate, and a fluid partitioning can, which is sandwiched between the motor housing and the pump casing and extends through the inner peripheral surface of the stator core to the inside of the recess; It is characterized by including a seal member provided between the inner peripheral surface of the can extending portion and the fixed side. Fluid pump.