JPH0949496A - Magnetic coupling pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a pump lock condition by foreign matter, composed of magnetic material, mixed in a fluid. SOLUTION: An impeller consisting of non-magnetic material is secured to a tip end of a rotary shaft 21, and a rotor magnet 23 is secured to a reverse surface of the impeller. An NS magnetized surface 23a of the rotor magnet 23 is opposed to a partition 4 with a fine air gap provided. A recessed part 22b, for adsorptively perceiving foreign matter composed of magnetic material to be mixed in a fluid by magnetic attractive force of the rotor magnet 23, is formed in the impeller from an obverse side toward a reverse side, and the rotor magnet 23 is partially exposed by the recessed part 22b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic coupling pump used as a water pump or the like arranged in a cooling circuit of an automobile.

[0002]

2. Description of the Related Art FIG. 5 shows a sectional view of a conventional magnetic coupling pump. This conventional magnetic coupling pump is configured by disposing a rotor 2, a stator 3 and a partition wall 4 between a suction port 1a and a discharge port 1b of a pump housing 1.

The rotor 2 has a rotating shaft 21, an impeller 22 made of a non-magnetic material fixed to the tip of the rotating shaft 21, and a back face of the impeller 22 fixed to the rotating shaft 21 in a plane perpendicular to the rotating shaft 21. 21 and a rotor magnet 23 having an NS magnetized surface 23a formed along the circumferential direction.

The stator 3 has the N of the rotor magnet 23.
Each of the stator cores 31 has a plurality of stator cores 31 whose end faces 31a are arranged along the circumferential direction so as to face the S magnetized surface 23a, and a stator coil 32 wound around each stator core 31. An exciting current is applied to the end faces 31a of the plurality of stator cores 31 to generate a rotating magnetic field.

The partition wall 4 is made of a resin material such as PPS resin (polyphenylene sulfide resin) and partitions the rotor 2 and the stator 3 while maintaining a minute gap with the NS magnetized surface 23a of the rotor magnet 23. Further, the partition wall 4 is formed with a bearing accommodating recess 41 for accommodating the bearing 24 formed of a bush and the bearing 25 receiving a thrust load.

The magnetic coupling pump having the above structure generates a rotating magnetic field on the end surfaces 31a of the plurality of stator cores 31, and applies a rotating torque from the stator core end surfaces 31a to the magnetized surface 23a of the rotor magnet 23 via the partition wall 4. By generating, the impeller 22 is rotated, and the fluid is sucked and discharged.

[0007]

However, as disclosed in Japanese Utility Model Laid-Open No. 56-34088, this type of magnetically coupled pump is not suitable for the NS of the rotor magnet 23.
The rotational torque of the impeller 22 is increased by setting the gap between the magnetized surface 23a and the partition wall 4 to a minute value. Therefore, when a foreign substance made of a magnetic material such as iron powder is mixed in the fluid, the foreign substance is N in the rotor magnet 23.
There is a possibility that the foreign matter that is attracted and accumulated on the S-magnetized surface 23a interferes with the partition wall 4 and that the impeller 22 cannot rotate, resulting in a pump lock state.

In view of the above problems, it is an object of the present invention to provide a magnetic coupling pump in which the above-described pump lock state does not occur when a foreign substance made of a magnetic material is mixed in the fluid. .

[0009]

According to a first aspect of the present invention, there is provided a rotary shaft, an impeller made of a non-magnetic material fixed to the tip of the rotary shaft, and a back face of the impeller fixed perpendicular to the rotary shaft. A rotor magnet having an NS magnetized surface formed along the circumferential direction centering on the rotation axis, and each end surface of the rotor magnet is circumferentially opposed to the NS magnetized surface. A plurality of stator cores arranged along the stator core and a stator coil wound around each of the stator cores are provided, and an exciting current is applied to each of the stator coils to generate a rotating magnetic field at the end faces of the plurality of stator cores. A magnetic coupling pump comprising a stator and partition walls for partitioning the rotor and the stator while maintaining a minute gap with the NS magnetized surface of the rotor magnet, The serial impeller, the suction foreign matter by magnetic attraction of the rotor magnet, a recess for accommodating employing a magnetic coupling pump, characterized in that formed from the surface side toward the back side.

According to a second aspect of the present invention, the magnetic coupling pump according to the first aspect is employed, wherein the recess partially exposes the rotor magnet.

[0011]

In the magnetic coupling pump according to the first aspect of the present invention, a rotating magnetic field is generated on the end faces of the plurality of stator cores about the rotating shaft due to the exciting current to the stator coils. When a rotating magnetic field is generated on the end surface of the stator core, a rotating torque is generated on the NS magnetized surface of the rotor magnet by the rotating magnetic field, the impeller is rotated, and fluid is sucked from the suction port and discharged from the discharge port.

Further, the impeller is formed with a concave portion from the front surface side to the rear surface side, and the concave portion allows the magnetic attraction force of the rotor magnet to act even on the front surface side of the impeller. Therefore, when a foreign substance made of a magnetic material such as iron powder is mixed in the fluid, the foreign substance receives the magnetic attraction force of the rotor magnet on the surface side of the impeller,
Adsorbed and accumulated in the recess. Therefore, most of the foreign matter mixed in the fluid is removed on the front surface side of the impeller, and the amount of foreign matter contained in the fluid that wraps around the back surface of the impeller is significantly reduced. Therefore, the amount of foreign matter adsorbed and accumulated on the NS magnetized surface of the rotor magnet, which is opposed to the partition wall while maintaining a minute gap, is significantly reduced, and the above-mentioned pump lock state due to the foreign matter can be prevented.

According to the magnetic coupling pump of claim 2,
Since a part of the rotor magnet is exposed to the surface side of the impeller by the recess, the magnetic attraction force of the rotor magnet acting on the surface side of the impeller is increased, and the foreign matter is more effectively attracted and accumulated in the recess. be able to.

[0014]

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

FIG. 1 shows a sectional view of a magnetic coupling pump according to one embodiment. The magnetic coupling pump according to this embodiment has the same structure as that of the impeller shown in FIG.
It is constructed similarly to the illustrated conventional magnetic coupling pump.

That is, the magnetic coupling pump according to the present embodiment is constructed by disposing the rotor 2, the stator 3 and the partition wall 4 between the suction port 1a and the discharge port 1b of the pump housing 1.

The rotor 2 is fixed to the rotary shaft 21, an impeller 22 made of a non-magnetic material fixed to the tip of the rotary shaft 21, and the back face of the impeller 22. 21 and a rotor magnet 23 having an NS magnetized surface 23a formed along the circumferential direction.

The impeller 22 has blades 22a formed on the front surface side, and from the front surface side to the back surface side,
A recess 22b is formed for adsorbing and containing a foreign substance made of a magnetic material such as iron powder mixed in the fluid by the magnetic attraction force of the rotor magnet 23. This recess 22b
As shown in FIGS. 2 (A) and 2 (B), is formed in an annular shape and partially exposes the rotor magnet 23 to the front surface side. The shape of the concave portion 22b is not limited to that shown in FIGS. 1 and 2A and 2B, but as shown in FIGS. Multiple circular holes arranged in or in Fig. 4 (A), (B)
As shown in FIG. 5, it may be formed by a plurality of annular grooves arranged concentrically. Further, the recess 22b may be configured so that the rotor magnet 23 is not exposed on the front surface side.

The stator 3 has the N of the rotor magnet 23.
Each of the stator cores 31 has a plurality of stator cores 31 whose end faces 31a are arranged along the circumferential direction so as to face the S magnetized surface 23a, and a stator coil 32 wound around each stator core 31. An exciting current is applied to the end faces 31a of the plurality of stator cores 31 to generate a rotating magnetic field.

The partition wall 4 is made of a resin material such as PPS resin (polyphenylene sulfide resin), and partitions the rotor 2 and the stator 3 with a slight gap from the NS magnetized surface 23a of the rotor magnet 23. Further, the partition wall 4 is formed with a bearing accommodating recess 41 for accommodating the bearing 24 formed of a bush and the bearing 25 receiving a thrust load.

The magnetic coupling pump having the above construction generates a rotating magnetic field on the end surfaces 31a of the plurality of stator cores 31, and the magnetic attraction force is applied to the magnetized surface 23a of the rotor magnet 23 from the stator core end surfaces 31a through the partition wall 4. By exerting the action, the impeller 22 is rotated, and the fluid is sucked and discharged.

When a foreign substance made of a magnetic material such as iron powder is mixed in the fluid, the foreign substance receives the magnetic attraction force of the rotor magnet 23 on the surface side of the impeller 22 and is attracted to the concave portion 22b. Accumulated. For this reason, most of the foreign matter mixed in the fluid is removed on the front surface side of the impeller 22, and the amount of the foreign matter contained in the fluid that wraps around the back surface of the impeller 22 is significantly reduced. Therefore, the partition wall 4
Thus, the amount of foreign matter adsorbed and accumulated on the NS magnetized surface 23a of the rotor magnet 23 facing each other while maintaining a minute gap is significantly reduced, and the pump lock state due to the above-mentioned foreign matter can be prevented. In addition, when a part of the rotor magnet 23 is exposed to the surface side of the impeller 22 by the recess 22b, the magnetic attraction force of the rotor magnet 23 acting on the surface side of the impeller 22 is increased, and the foreign matter is more effectively removed. It can be adsorbed and accumulated in the recess.

As described above, according to this embodiment, it is possible to prevent the pump lock state due to foreign matter.

[Brief description of drawings]

FIG. 1 is a sectional view of a magnetic coupling pump according to an embodiment.

FIG. 2 is a plan view and a BB cross-sectional view of the impeller.

FIG. 3 is a plan view and a BB cross-sectional view of an impeller according to a modified example.

FIG. 4 is a plan view and BB of an impeller according to another modification.
Sectional view

FIG. 5 is a sectional view of a magnetic coupling pump according to a conventional example.

[Explanation of symbols]

 2 rotor 21 rotating shaft 22 impeller 22b recess 23 rotor magnet 23a NS magnetized surface 3 stator 31 stator core 32 stator coil 4 partition wall

Claims (2)

[Claims] 1. A rotary shaft, an impeller made of a non-magnetic material fixed to the tip of the rotary shaft, and a rotary shaft fixed to the back surface of the impeller and centered on the rotary shaft in a plane perpendicular to the rotary shaft. A rotor magnet having an NS magnetized surface formed along the circumferential direction of the rotor magnet, and a plurality of stator cores, each end surface of which is arranged along the circumferential direction so as to face the NS magnetized surface of the rotor magnet. A stator that is wound around each of the stator cores, and applies an exciting current to each of the stator coils to generate a rotating magnetic field at the end surfaces of the plurality of stator cores; A magnetic coupling pump comprising partition walls for partitioning the rotor and the stator while maintaining an NS magnetized surface and a minute gap, wherein the impeller has the rotor magnet. A magnetic coupling pump characterized in that a concave portion for adsorbing and containing a foreign substance by a magnetic attraction force of a net is formed from a front surface side to a back surface side. 2. The magnetic coupling pump according to claim 1, wherein the recess partially exposes the rotor magnet.