Water Pump Especially for Ponds, Aquariums, Fountains or the Like

Abstract

A water pump has a housing with a pump housing part, provided with an intake opening and an exit opening, and a motor housing part. An impeller with a shaft is rotatably arranged in the pump housing part. An electric pump motor is arranged in the motor housing part, wherein the pump motor comprises a stator having several coils arranged on several stator poles and a rotor rotating in the stator. The pump motor is an electronically communicated motor. The stator is comprised of a pack of unitary laminations, respectively. The pump motor has control electronics arranged in the motor housing part. The stator with its coils and the control electronics are water-tightly encapsulated.

What is claimed is: 
     
         1 . A water pump comprising:
 a housing comprising a pump housing part, provided with an intake opening and an exit opening, and a motor housing part;   an impeller with a shaft rotatably arranged in the pump housing part;   an electric pump motor arranged in the motor housing part, wherein the pump motor comprises a stator having several coils arranged on several stator poles and a rotor rotating in the stator;   wherein the pump motor is an electronically communicated motor;   wherein the stator is comprised of a pack of unitary laminations, respectively;   wherein the pump motor has control electronics arranged in the motor housing part; and   wherein the stator and the coils and the control electronics are water-tightly encapsulated.   
     
     
         2 . The water pump according to  claim 1 , wherein the rotor is embodied as a two-pole permanent magnet. 
     
     
         3 . The water pump according to  claim 1 , wherein the coils are pushed onto the stator poles from the interior of the stator. 
     
     
         4 . The water pump according to  claim 1 , wherein the pump motor further comprises a can that separates the rotor and the stator from one another. 
     
     
         5 . The water pump according to  claim 4 , wherein the can is comprised of plastic material that is not externally reinforced. 
     
     
         6 . The water pump according to  claim 1 , wherein the pump motor further comprises a solid, at least substantially closed iron ring that is arranged between the rotor and the shaft. 
     
     
         7 . The water pump according to  claim 1 , wherein the control electronics have a signal evaluation unit that evaluates signals modulated onto mains current supplied to the water pump and employs the signals for speed regulation of the pump motor. 
     
     
         8 . The water pump according to  claim 1 , wherein for the stator and the coils the following geometric conditions apply: 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   a < A1 
                   a < A2 
                 
                     
                   b < B1 
                   b < B2 
                 
                     
                   c < C, 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
               
            
           
         
         wherein: a=length of the coils;
 A 1 =minimal spacing between two opposed inner pole sides of the stator poles; 
 A 2 =length of the stator poles; 
 b=width of the coils; 
 B 1 =minimal spacing of two inner pole edges of the stator poles, between which inner pole edges precisely one other stator pole is located; 
 B 2 =minimal spacing of two outer coil edges of the coils in the mounted states, between which precisely one other coil is located; 
 c=width of the stator poles; 
 C=inner width of the coils. 
 
       
     
     
         9 . The water pump according to  claim 8 , wherein an inner arc length of the stator poles is reduced by approximately 11 percent to 12 percent relative to a circumference of a circle contacting the inner pole sides of the stator poles and divided by twice the number of the stator poles. 
     
     
         10 . The water pump according to  claim 8 , wherein for the stator approximately the following geometric condition applies:
   0.88×360 degrees/n<=α<=0.89×360 degrees/n
   wherein: α=angle between two straight lines extending from the stator center and touching the inner pole edges of the stator poles;   n=number of stator poles.