Centrifugal Pump

Abstract

The invention relates to a centrifugal pump ( 10 ) for liquids, comprising a pump spiral housing ( 12 ) and a pump wheel ( 28 ), which is driven by an integrated electromotor ( 14, 20, 34, 36 ), whereby the rotational axis thereof ( 29 ) is arranged in a coaxial in relation to the rotational axis ( 37 ) of the pump wheel ( 28 ). The pump spiral housing ( 12 ) is sealed by a sealing ring ( 72 ) and is connected to the motor housing by means of a bayonet catch ( 74, 78 ) and covers the front side thereof. According to the invention, the motor housing ( 14 ) is pot-shaped and is made of plastic and the base thereof ( 13 ) which is oriented towards the pump spiral housing ( 12 ) forms a common housing wall in relation to the pump spiral housing ( 12 ).

1 . A centrifugal pump ( 10 ) for liquids having a pump spiral housing ( 12 ) and a pump impeller ( 28 ), which is driven by an integral electric motor ( 14 ,  20 ,  34 ,  36 ), the axis of rotation ( 29 ) of which is arranged coaxially with the axis of rotation ( 37 ) of the pump impeller ( 28 ), the pump spiral housing ( 12 ) being sealed by a sealing ring ( 72 ) and connected to the motor casing ( 14 ) means of a bayonet catch ( 74 ,  78 ), covering the end face of the motor casing, characterized in that the motor casing ( 14 ) is of canister-shaped design and is made from plastics, its base ( 13 ) facing the pump spiral housing ( 12 ), forming a common housing wall with the pump spiral housing ( 12 ). 
   
   
       2 . The centrifugal pump ( 10 ) as claimed in  claim 1 , characterized in that the base ( 13 ) has a protuberance, facing the open end of the motor casing ( 14 ) and concentric with the axis of rotation ( 29 ), with an approximately cylindrical dividing wall ( 19 ) and an internal base ( 17 ), which in its central area has a thickening ( 18 ), in which a bearing axis ( 22 ) pointing towards the pump spiral housing ( 12 ) is injection molded, on which a rotor ( 36 ) of the electric motor is rotatably supported. 
   
   
       3 . The centrifugal pump ( 10 ) as claimed in  claim 2 , characterized in that the rotor ( 36 ) and the pump impeller ( 28 ) are integrally formed and are supported by way of an injected-molded bearing ( 30 ) on the bearing axis ( 22 ). 
   
   
       4 . The centrifugal pump ( 10 ) as claimed in  claim 3 , characterized in that the bearing axis ( 22 ), at its free end, carries a mushroom-type stop ( 24 ), which axially secures the bearing ( 30 ) in that the mushroom-type stop ( 24 ) engages by means of a twist lock in a recess ( 32 ) in the longitudinal axis ( 22 ). 
   
   
       5 . The centrifugal pump ( 10 ) as claimed in  claim 1 , characterized in that a coil shell ( 40 ) of a stator ( 34 ) of the electric motor is inserted in an annular space between the dividing wall ( 19 ) and the outer wall ( 15 ) of the motor casing ( 14 ) and seals the annular space with one end wall ( 41 ). 
   
   
       6 . The centrifugal pump ( 10 ) as claimed in  claim 5 , characterized in that the coil shell ( 40 ), in the area of the annular space, is wound from the end wall ( 41 ) to the base ( 13 ) of the motor casing ( 14 ) with varnished copper wire ( 52 ), the wire ends of which are laid to support points ( 42 ,  44 ,  46 ) for insulation displacement connectors ( 48 ). 
   
   
       7 . The centrifugal pump ( 10 ) as claimed in  claim 6 , characterized in that a stator ring ( 38 ) is pressed over the coil formed from the varnished copper wire ( 52 ) onto the coil shell ( 40 ) as far as the end wall ( 41 ). 
   
   
       8 . The centrifugal pump ( 10 ) as claimed in  claim 5 , characterized in that the end wall ( 41 ) has projections ( 56 ) on its circumference, which by turning the coil shell ( 40 ) relative to the motor casing ( 14 ) during the assembly process engage behind inwardly projecting undercuts ( 62 ) on the motor casing ( 14 ) in the manner of a bayonet catch. 
   
   
       9 . The centrifugal pump ( 10 ) as claimed in  claim 6 , characterized in that at least one coding ( 64 ) is provided in the area of the undercuts ( 62 ). 
   
   
       10 . The centrifugal pump ( 10 ) as claimed in  claim 5 , characterized in that the support points ( 42 ,  44 ,  46 ) with insulation displacement connections ( 48 ) are arranged on the end wall ( 41 ) on the side facing the opening in the motor casing ( 14 ), a printed circuit board ( 94 ), the tracks of which are bonded by press-in contacts ( 86 ) of the insulation displacement connections ( 48 ), resting on the support points ( 42 ,  44 ,  46 ). 
   
   
       11 . The centrifugal pump ( 10 ) as claimed in  claim 5 , characterized in that a Hall sensor ( 98 ), the pins ( 54 ) of which are electrically bonded to the insulation displacement connections ( 48 ) by pressing the insulation displacement connections ( 48 ) into the associated support point ( 44 ), is inserted into a pocket ( 60 ) in the end wall ( 41 ) of the motor housing ( 14 ) on the side facing the rotor ( 36 ). 
   
   
       12 . The centrifugal pump ( 10 ) as claimed in  claim 5 , characterized in that a hooked catch ( 58 ), which engages in a recess ( 66 ) on the motor casing ( 14 ) and circumferentially fixes the coil shell ( 40 ) in relation to the motor casing ( 14 ), is provided on the circumference of the end wall ( 41 ). 
   
   
       13 . The centrifugal pump ( 10 ) as claimed in  claim 10 , characterized in that the hooked catch ( 58 ) adjoins a projection ( 56 ) of the coil shell ( 40 ). 
   
   
       14 . The centrifugal pump ( 10 ) as claimed in  claim 1 , characterized in that the coil shell ( 40 ) supports the dividing wall ( 19 ) and/or the internal base ( 17 ) of the motor housing ( 14 ). 
   
   
       15 . The centrifugal pump ( 10 ) as claimed in  claim 1 , characterized in that the opening in the motor housing ( 14 ) is sealed by an electronics cover ( 20 ), which has axially oriented connector pins ( 88 ), which project through an injection molded seal ( 26 ) into the motor casing ( 14 ) and engage in a power connection ( 100 ) of the coil shell ( 40 ). 
   
   
       16 . The centrifugal pump ( 10 ) as claimed in  claim 15 , characterized in that axially oriented, inward-pointing pins ( 90 ), which engage in pre-centering sleeves ( 50 ) provided on the coil shell ( 40 ) for pre-centering in relation to the coil shell ( 40 ), are molded onto the electronics cover ( 20 ). 
   
   
       17 . The centrifugal pump ( 10 ) as claimed in  claim 15 , characterized in that the electronics cover ( 20 ), on its circumference, has radially pliable hooked catches ( 92 ), which engage in recesses ( 16 ) in the motor housing ( 14 ). 
   
   
       18 . The centrifugal pump ( 10 ) as claimed in  claim 15 , characterized in that the electronics cover ( 20 ), offset axially inwards in relation to the hooked catches ( 92 ), has a radially acting sealing ring ( 96 ), which bears tightly against the inside of the outer wall ( 15 ) of the motor casing ( 14 ). 
   
   
       19 . The centrifugal pump ( 10 ) as claimed in  claim 12 , characterized in that the inside of the outer wall ( 15 ) diverges conically in relation to the opening in the motor casing ( 14 ).