Fluid pump

Abstract

A fluid pump includes a pump casing, an impeller arranged in the pump casing, and a motor for driving the impeller to rotate in the pump casing. The motor includes a stator and a rotor connecting to the impeller. A motor shaft is fixed arranged in the fluid pump, with one end of the motor shaft connected to the pump casing. The impeller and the rotor are rotatably placed around the motor shaft, and a washer is placed around the motor shaft and axially sandwiched between the pump casing and the rotor, for limiting an axial movement of the rotor and the impeller.

1 . A fluid pump comprising:
 a pump casing;   an impeller arranged in the pump casing; and   a motor for driving the impeller to rotate in the pump casing, the motor comprising a stator and a rotor connecting to the impeller;   wherein a motor shaft is fixed arranged in the fluid pump, one end of the motor shaft is connected to the pump casing, the impeller and the rotor are rotatably placed around the motor shaft, and a washer is placed around the motor shaft and axially sandwiched between the pump casing and the rotor, for limiting an axial movement of the rotor and the impeller.   
     
     
         2 . The fluid pump of  claim 1 , wherein the washer comprises a first end and a second end opposite to the first end, the first end is axially abutted against the pump casing, and the second end is axially abutted against the rotor, an outer diameter of the first end is less than an outer diameter of the second end. 
     
     
         3 . The fluid pump of  claim 2 , wherein an end face of the second end of the washer defines one or more communicating grooves radially extending through the washer. 
     
     
         4 . The fluid pump of  claim 2 , wherein a center of the pump casing is formed with a first shaft seat, one end of the motor shaft is inserted and fixed into the first shaft seat, the first end of the washer is abutted against an end surface of the first shaft seat, and the outer diameter of the first end is not greater than an outer diameter of the end surface of the first shaft seat. 
     
     
         5 . The fluid pump of  claim 2 , wherein the washer further comprises a flow-guiding portion disposed between the first end and the second end, and an outer diameter of the flow-guiding portion gradually increases from the first end to the second end. 
     
     
         6 . The fluid pump of  claim 5 , wherein the washer further comprises a neck portion arranged between the first end and the flow-guiding portion, an outer diameter of the neck portion is less than the outer diameter of the first end. 
     
     
         7 . The fluid pump of  claim 2 , wherein the second end of the washer passes through the impeller and abuts against the rotor, the second end and the impeller are radially gap-fitted. 
     
     
         8 . The fluid pump of  claim 7 , wherein the rotor comprises a bearing mounted on the motor shaft adjacent to the impeller, the second end of the washer abuts against the bearing. 
     
     
         9 . The fluid pump of  claim 2 , wherein an inner cavity of the second end of the washer is non-circular, and a cross-section of the end of the motor shaft corresponding to the washer is also non-circular, the washer and the motor shaft are circumferentially positioned through shape fitting. 
     
     
         10 . The fluid pump of  claim 1 , further comprising a sleeve separating the stator from the rotor and impeller, wherein a second shaft seat is formed at a center of the sleeve, and the other end of the motor shaft is fixed in the second shaft seat. 
     
     
         11 . The fluid pump of  claim 1 , wherein the rotor comprises a rotor core, one or more permanent magnets, two bearings, and a rotor shell encapsulating the rotor core, the permanent magnets and the bearings through injection molding, the rotor is rotatably connected to the motor shaft through the two bearings. 
     
     
         12 . The fluid pump of  claim 11 , wherein the impeller is also injection molded with the rotor shell.