Magnetic coupling pump

Abstract

A magnetic coupling pump according to the present invention has a housing including a pump chamber a motor chamber. The rotor includes a plurality of impellers projected from top face of a substantially disc-shaped main body of the rotor to be located in the pump chamber, and a substantially cylindrical magnet section projected from back face of the main body to be located in the motor chamber. The rotor is located in engine coolant, and is driven by a stator located inward of the magnet section in the motor chamber for sucking coolant from an inlet port and exhausting it from an outlet port. The pump is provided along an inner circumference of the stator with a cavity communicating with passages of fluid along an inner circumference of the magnet section and the back face of the main body of the magnet section. The cavity admits the coolant. The pump according to the present invention is able to prevent heat-up in the inner circumferential part of the stator.

Description

[0001] The present application claims priority from Japanese Patent Application No. 2003-142389 of Hatano, filed on May 20, 2003, the entirety of which is hereby incorporated into the present application by reference.[0002] 1. Field of the Invention[0003] The present invention relates to a magnetic coupling pump for pumping fluids such as engine coolant for vehicles, and more particularly, relates to an outer-rotor type magnetic coupling pump in which a stator is located toward a rotation center of a rotor having impellers for feeding fluids, and a substantially cylindrical magnet section of the rotor is located around the stator.[0004] 2. Description of the Related Art[0005] In conventional outer-rotor type magnetic coupling pumps for engine coolant for vehicles, a rotor having impellers for feeding coolant is located in a housing, as disclosed in Japanese Laid Open Patent Application No. JP10-311290.[0006] In this magnetic coupling pump, the housing includes a pump chamber having ...

AI Technical Summary

Benefits of technology

[0011] Therefore, the magnetic coupling pump of the present invention is able to prevent heat -up of the inner circumferential part of the stator and burnout of coils of the stator, whereby becomes durable even under high-load driving which consumes a lot of electricity.

[0012] If the main body of the rotor is provided in the vicinity of an inner circumferential part of the stator with a plurality of through holes, the fluid in the cavity is able to flow into the pump chamber via the through holes of the rotor main body. That is, the fluid forms a cooling stream for cooling the stator that flows from the outer circumferential side to the inner circumferential side of the stator, and further flows from the inner circumferential side of the stator to the pump chamber. Therefore, heat-up of the inner circumferential part of the stator is further prevented, and in addition, heat-up of the outer circumferential side of the stator is properly prevented, too. Consequently, burnout of the coils of the stator and heat deformation of the housing are properly prevented, which further elongates a life span of the pump even under high-load driving which consumes a lot of electricity.

[0013] When the rotor includes a shaft section projecting into the cavity, the shaft section is desirably provided in its outer circumference with a plurality of impellers for stirring the fluid. With this arrangement, the impellers are able to stir the fluid in the cavity when the rotor is driving, and therefore, entire area of the inner part of the stator is cooled down quickly and properly.

[0014] When the rotor includes a shaft section projecting into the cavity, moreover, it will also be appreciated that the shaft section internally includes a passage with apertures opening in the cavity and in a top face side of the main body, such that the fluid in the cavity circulates to the top face side of the main body through the passage. With this arrangement, the fluid in the cavity is able to flows out toward the top face side of the rotor main body or into the pump chamber via the passage of the shaft section. Especially, the fluid in a bottom part of the cavity is also able to circulate to the pump chamber via the passage. Therefore, cooling-down effect of the inner circumferential part of the stator is enhanced.

[0015] Furthermore, if the rotor is rotatably supported at two positions of a position proximate to the main body and at a position in the cavity, the rotation of the rotor is stabilized, which reduces the loss of rotation moment of the rotor.

Problems solved by technology

In the conventional outer-rotor type magnetic coupling pump, however, there is no means of cooling down a part inward of the stator though the outer circumference of the stator can be cooled down by coolant interposed between the stator and the magnet section.

Consequently, burnout of the coils of the stator and heat deformation of the housing are properly prevented, which further elongates a life span of the pump even under high-load driving which consumes a lot of electricity.

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