Draining pump

Abstract

The invention discloses a draining pump. The draining pump is characterized by comprising an impellor and a brushless motor used for driving the impellor. The impellor comprises a wheel disc and a plurality of blades arranged on the wheel disc. The blades extend from the surface of the wheel disc along the axial direction of the impellor, are away from the surface of the wheel disc, and are provided with first ends adjacent to the axis of the impellor and second ends which are away from the axis of the impellor and opposite to the first ends. A plane, perpendicular to the axis of the impellor, of the impellor is provided with a smooth curved cross section shape. The cross section shape comprises at least a first arc-shaped region segment adjacent to the first ends and a second arc-shaped region segment adjacent to the second ends, wherein the first arc-shaped region segment is provided with a first radius of curvature, and the second arc-shaped region segment is provided with a second radius of curvature different from the first radius of curvature. The draining pump is simple in structure, long in service life, and suitable for volume production.

Description

technical field [0001] The invention relates to the technical field of drainage pumps, and more specifically, the invention relates to a drainage pump and its impeller. Background technique [0002] At present, motors of drain pumps used for circulating water or draining water in household appliances such as dishwashers and washing machines are usually induction motors or single-phase permanent magnet synchronous motors. Due to its low efficiency, complex structure, large volume, and high cost, induction motors have gradually withdrawn from the application field of drain pumps for household appliances such as dishwashers and washing machines. The single-phase permanent magnet synchronous motor itself cannot achieve directional rotation, and a non-return mechanism needs to be added to the rotor structure to prevent the motor from rotating in reverse. Moreover, the motor structure of the single-phase permanent magnet synchronous motor is relatively complicated, and the startin...

AI Technical Summary

Problems solved by technology

Due to low efficiency, complex structure, large volume and high cost, induction motors have gradually withdrawn from the application field of drainage pumps for household appliances such as dishwashers and washing machines

The single-phase permanent magnet synchronous motor itself cannot achieve directional rotation. It is necessary to add a non-return mechanism to the rotor structure to prevent the motor from rotating in reverse. Moreover, the motor structure of the single-phase permanent magnet synchronous motor is relatively complicated, and the starting noise is relatively large.

[0003] On the other hand, the impellers used in the existing drainage pumps of household appliances such as washing machines and dishwashers are generally composed of several blades installed on the shaft sleeve, and the blades are straight blades. The purpose of drainage is achieved under the action, and the disadvantage is that the water flow of the drainage pump is small, the internal friction is large, and there is also some shear force in the axial direction of the water flow, which will squeeze the end cover and the motor shaft, resulting in deformation of the end cover, and the rotor assembly is offset and cannot work normally. , forming noise

At the same time, because there is a certain gap between the impeller and the pump base, the water will generate eddy currents under the action of axial shear force, and household appliances such as washing machines and dishwashers will contain more or less sewage in the discharged sewage. These debris follow the vortex of the water, reach the bearing, and wind up on the shaft of the water pump. After a long time of operation, the wound debris gradually increases, causing resistance to the pump shaft and preventing normal drainage. In severe cases, the water pump will be blocked and burnt out

[0004] With the introduction of the concept of green home appliances and the enhancement of environmental protection awareness, the existing drainage pumps can no longer meet the increasing requirements for the comfort of the living environment.

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