Submersible pump

Abstract

A motor-driven submersible pump is provided with highly chemical resistant body parts, a multistage shaft seal including a self-aligning flexible sheet lip seal, a grounding wire arrangement to electrically neutralize the environment in which the pump operates and an improved encapsulation of the motor by epoxy encapsulation material or the like.

1 . A motor-driven pump adapted for being submersed in fluid comprising: 
 an electric motor disposed in a motor housing, the motor containing a rotating shaft extending to and supporting an impeller;    a motor cover fitted to the motor housing to enclose the motor, at least one of the motor housing and the motor cover being provided with a pour hole through which a non-conductive encapsulation material may be poured to encapsulate the motor;    an impeller housing that surrounds the impeller and including a fluid inlet and a fluid discharge conduit for fluid flow; and    a multistage seal disposed between the motor and the impeller that prevents fluid from contacting the motor.    
   
   
       2 . The motor-driven pump of  claim 1 , wherein the motor cover is fitted on the motor housing by cooperating latch means.  
   
   
       3 . The motor-driven pump of  claim 1 , wherein the non-conductive encapsulation material is an epoxy.  
   
   
       4 . The motor-driven pump of  claim 1 , wherein an impeller cover is secured to the impeller housing with an o-ring disposed therebetween to prevent fluid from leaking out from within the interior of the impeller housing.  
   
   
       5 . The motor-driven pump of  claim 1 , wherein a void space is provided between the impeller and the seal to reduce fluid pressure build-up on the seal.  
   
   
       6 . The motor-driven pump of  claim 1 , wherein the seal comprises a self-aligning seal.  
   
   
       7 . The motor driven pump of  claim 6  wherein: 
 the self-aligning seal comprises a flexible sheet-like member including an undersize bore and fitted over the shaft between the impeller and the motor.    
   
   
       8 . The motor-driven pump of  claim 6 , wherein the seal comprises a lip seal disposed between the self-aligning seal and the motor.  
   
   
       9 . The motor-driven pump of  claim 8 , wherein the seal further comprises a moisture barrier disposed between the lip seal and the motor.  
   
   
       10 . The motor-driven pump of  claim 9 , wherein: 
 the moisture barrier comprises grease packing disposed in a cavity formed in a bracket member of the motor.    
   
   
       11 . The motor-driven pump of  claim 1  further comprising electrical grounding circuit that electrically neutralizes the environment in which the motor-driven pump operates.  
   
   
       12 . The motor-driven pump of  claim 11 , wherein the grounding circuit comprises a first ground wire attached to the motor and to a wall of the motor housing and a second ground wire connected on one end of a wall of the motor housing and spaced from the connection of the first ground wire to the motor housing.  
   
   
       13 . The motor-driven pump of  claim 11 , wherein the motor housing is stainless steel and resistant to fluids that are highly corrosive.  
   
   
       14 . A motor-driven pump capable of being submersed in fluid comprising: 
 a polymer-encapsulated motor encased in a motor housing, the motor containing a rotating shaft extending to and supporting an impeller;    a motor cover fitted to the motor housing to enclose the motor, the motor cover being provided with a pour hole through which polymer encapsulation material may be poured to encapsulate the motor;    an impeller housing that surrounds the impeller with an inlet and discharge outlet for fluid flow; and    a multistage seal disposed between the motor cover and the impeller that prevents fluid from contacting the motor, the multistage seal comprising a self-aligning first lip seal, a second lip seal journalled by a member forming part of the motor and a grease packing moisture barrier.    
   
   
       15 . A motor-driven pump adapted for being submersed in fluid comprising: 
 an electric motor disposed in a motor housing, the motor containing a rotating shaft extending to and supporting an impeller;    a motor cover fitted to the motor housing to enclose the motor, at least one of the motor housing and the motor cover being provided with a pour hole through which a non-conductive encapsulation material may be poured to encapsulate the motor;    an impeller housing that surrounds the impeller and including a fluid inlet and a fluid discharge conduit for fluid flow;    a multistage seal disposed between the motor and the impeller that prevents fluid from contacting the motor, the multistage seal comprising a self-aligning first lip seal, a second lip seal and a grease packing moisture barrier; and    an electrical grounding circuit that electrically neutralizes the environment in which the motor-driven pump operates, wherein the grounding circuit comprises a first ground wire attached to the motor and to a wall of the motor housing and a second ground wire connected on one end of a wall of the motor housing and spaced from the connection of the first ground wire to the motor housing.