JP3355515B2 - Magnetic coupling pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor-driven magnetic coupling pump applied to a water pump for an automobile and the like.

[0002]

2. Description of the Related Art Conventionally, as this kind of magnetic coupling pump,
A pump chamber and a motor chamber are formed in the pump housing via a partition, and a stator of an axial air gap type motor is disposed in the motor chamber, and a rotation shaft is axially supported at a center position of the stator. An impeller is fixed to a tip end of a rotating shaft protruding from the rotor, and a pump device having a configuration in which an annular magnet having NS poles alternately magnetized in the circumferential direction is attached to a partition wall side, that is, a stator side of the impeller, is disclosed in Japanese Patent Application Laid-Open No. HEI 9-163191. 59-591
This is known from Japanese Patent Publication No.

[0003]

In this conventional magnetic coupling pump, an exciting current is supplied to a plurality of stator coils provided on the circumference of the stator to generate a rotating magnetic field on the end faces of the plurality of stator cores. As a result, a magnetic attraction force is applied between the annular magnet on the impeller side and the impeller operates to rotate. However, an impeller with an annular magnet serving as a rotor has a cantilever type rotating shaft, there is some clearance between the rotating shaft and the bearing, and the impeller has a support means against radial swing. If the rotation balance of the impeller is poor, vibrations are likely to occur in the impeller,
In addition, there is a problem in that when run-out occurs on the rotating shaft, drive noise is generated and wear of the bearing increases.

[0004] The present invention has been made in view of the above points, and an object of the present invention is to provide a magnetic coupling pump capable of effectively reducing runout of an impeller and vibration of a rotating shaft.

As a result of various experiments and research and development, the present inventors have found that the conventional magnetic coupling pump has the same center radius R1 of the annular magnet 35 and the center radius R2 of the stator as shown in FIG. The annular magnet 35 on the vehicle side is the stator core 31
3, the magnetic attraction is applied only in the axial direction of the rotating shaft and does not act in the radial direction. However, as shown in FIG. 3, the center radius R3 of the annular magnet 15 is changed to the center radius of the stator. R2, and when the annular magnet 15 is positioned obliquely inside the stator core 21, the annular magnet 15
It has been found that a force F directed outwardly acts around the impeller, and the force F acts to suppress the radial swing of the impeller.

[0006]

In order to achieve the above object, the present invention provides a magnetic coupling pump in which a pump chamber and a motor chamber are formed in a housing via a partition, and a center of a stator disposed in the motor chamber. A rotating shaft is supported at the position, an impeller is fixed to the tip of the rotating shaft protruding toward the pump chamber, and an annular magnet forming a part of the rotor of the motor is attached to the partition wall side of the impeller. In the coupling pump, a center radius of the annular magnet is formed to be smaller than a center radius of a circle connecting centers of the plurality of stator cores of the stator.

The outer peripheral surface of the annular magnet is located inside the outer peripheral position of the stator core, the inner peripheral surface of the annular magnet is located inside the inner peripheral surface of the stator core, and the annular magnet and each stator core are connected to each other. Are arranged so as to have a vertically overlapping portion.

[0008]

[Operation and effect] In the magnetic coupling pump having such a configuration,
When the impeller is driven to rotate, the center radius of the annular magnet is formed smaller than the center radius of each stator core. , A radial force acts outward, and the force F acts to suppress the runout of the impeller.

Therefore, even if there is some clearance between the rotating shaft and its bearing, and even if the rotation balance of the impeller is somewhat poor, a force acts in the outer circumferential direction (radial direction) of the annular magnet during rotation. The run-out of the vehicle is effectively suppressed, and the suppression of the run-out of the impeller also reduces the drive noise due to the vibration of the rotating shaft, thereby reducing bearing wear.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a magnetic coupling pump applied to a cooling water circulation pump for an automobile. Reference numeral 1 denotes a housing of the pump.
A pump chamber 3 is formed above and a motor chamber 4 is formed below,
The bottom of the housing 1 is closed by a lid 5.

The partition 2 is formed, for example, with a bearing recess at the center made of PPS resin or the like. Two bearing metals 6 and 7 are fitted into the bearing recess communicating with the pump chamber 3 side. The rotating shaft 11 of the impeller 10 is rotatably fitted into the shaft.

The impeller 10 has a plurality of blades 13 provided on an upper surface of a disk-shaped main body 12, and an annular magnet 15 is mounted on a lower surface thereof, that is, on a partition wall side via a magnetic plate 14 for magnetic reinforcement. . The main body 12 and the blades 13 are made of a nonmagnetic copper alloy or PPS resin.

The annular magnet 15 is formed in a ring shape from a ferromagnetic material such as ferrite, and N poles and S poles are alternately arranged in the circumferential direction every 90 degrees. In addition, this annular magnet 15
Is formed smaller than a center radius R2 of a circle connecting the centers of the stator cores 21 described later.

A suction port 9 is formed in the upper part of the housing 1 of the pump chamber 3, and a discharge port (not shown) is formed in a side wall of the pump chamber 3.

On the other hand, the annular magnet 1 is provided in the motor chamber 4.
A stator 20 of an axial air gap type motor having 5 as a part of a rotor is arranged around a rotating shaft 11 with, for example, six magnetic poles arranged at equal intervals. As shown in FIG. 2, each stator core 21 of the stator 20 is formed in a columnar shape, and is disposed at intervals of 60 degrees on a circle having the center of the rotating shaft 11 as a circle. The magnetic plate 22 for reinforcement is fixed.

Each stator core 21 has a bobbin 23
, The stator coil 24 is wound. Note that 25
Is a control board disposed on the upper part of the stator 20;
The end of each stator coil 24 is connected to the substrate 25 to control the exciting current supplied to the coil.

As shown in FIG. 2, six stator cores 2
1 is arranged such that its center is located on the circumference of a circle C1 having a radius R2 (a circle centered on the axis of the rotating shaft 11). On the other hand, the annular magnet 15 is disposed concentrically with the rotating shaft 11, that is, concentrically with the circle C1 connecting the stator core, and a center radius R3 of a center circle C2 passing through the center of the magnet connects the center of the stator core 21. It is formed smaller than the radius R2 of the circle C1.

If the center radius R3 of the annular magnet 15 is too small, the distance from the end face of each stator core 21, that is, the air gap increases, and the driving force for rotating the impeller 10 as a rotor decreases. For this reason, the limit of making the center radius R3 of the annular magnet 15 smaller than the radius R2 of the circle C1 of the stator core 21 is at least the limit of the annular magnet 1
5 and a part of the end face of each stator core 21 need to be overlapped.

Thus, the center radius R3 of the annular magnet 15 is
Is smaller than the center radius R2 of the circle C1 connecting the centers of the stator cores 21 so that the outer peripheral surface of the annular magnet 15 is located inside the circle connecting the outer surfaces of the stator cores 21 as shown in FIG. In addition, the inner peripheral surface position of the annular magnet 15 is located inside a circle connecting the inner peripheral surfaces of the stator cores 21, and when the rotating shaft 11 is driven, a force F directed to the outer peripheral direction is applied to the annular magnet 15. Generated and this force F
Acts to suppress the runout of the impeller 10.

In the magnetic coupling pump having the above configuration, when an exciting current is supplied to each stator coil 24 at a predetermined timing, a rotating magnetic field is generated in the stator 20, and a magnetic attraction force acts on the annular magnet 15 of each stator core 21. The annular magnet 15, that is, the impeller 10 rotates around the rotation shaft 11. By the rotation of the impeller 10, the water sucked from the suction port 9 is pumped from the discharge port.

When the impeller 10 is driven to rotate, the center radius R3 of the annular magnet 15 is formed to be smaller than the center radius R2 of each stator core 21. Therefore, as shown in FIG. Ring magnet 15 on the inside
Will be located. For this reason, a radial force F directed outward around the annular magnet 15 acts on the annular magnet 15, and the force F acts to suppress the runout of the impeller 10.

Therefore, even if there is some clearance between the rotary shaft 11 and its bearing, and even if the rotational balance of the impeller 10 is somewhat poor, a force F acts in the outer circumferential direction (radial direction) of the annular magnet 15 during rotation. In order to do, the impeller 1
The swing of 0 is effectively suppressed. By suppressing the run-out of the impeller 10, the drive noise due to the vibration of the rotary shaft 11 is reduced, and the wear of the bearing metals 6, 7 can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a magnetic coupling pump according to an embodiment of the present invention.

FIG. 2 is an explanatory plan view showing a positional relationship between a stator and an annular magnet of the pump.

FIG. 3 is an explanatory diagram showing the direction of a force F acting on an annular magnet during rotation.

FIG. 4 is an explanatory diagram showing a force acting on an annular magnet of a conventional magnetic coupling pump.

[Explanation of symbols]

 Reference Signs List 1-housing 2-partition wall 3-pump room 4-motor room 10-impeller 11-rotation shaft 15-annular magnet 20-stator 21-stator core

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F04D 13/06 F04D 13/02

Claims (2)

(57) [Claims] 1. A pump chamber and a motor chamber are formed in a housing via a partition, and a rotary shaft is supported at a center position of a stator disposed in the motor chamber, and the rotary shaft projects toward the pump chamber. A magnetic coupling pump having an impeller fixed to the tip of the rotor, and an annular magnet forming a part of the rotor of the motor mounted on the partition wall side of the impeller. A magnetic coupling pump formed to be smaller than a radius of a circle connecting the centers of the stator cores. 2. An outer peripheral surface position of the annular magnet is located inside a circle connecting the outer surfaces of the respective stator cores, and an inner peripheral surface position of the annular magnet is located inside a circle connecting the inner peripheral surfaces of the respective stator cores. 2. The magnetic coupling pump according to claim 1, wherein the magnetic coupling pump is located such that the annular magnet and each stator core have a vertically overlapping portion.