Polymeric External Gear Pump for Hot Cooking Oil

Abstract

An overhung external spur gear positive displacement pump for hot oil or deep fryer applications is disclosed. The external gear pump includes a thermoplastic casing that includes a through bore for accommodating a drive shaft that leads to a pump chamber that accommodates a drive gear and a driven gear. The thermoplastic casing is connected to a stationary pin. The thermoplastic casing also includes a proximal end coupled to a motor and a distal end coupled to a thermoplastic head. The gears are enclosed in the pump chamber by the thermoplastic head. The stationary pin is accommodated within the driven gear and the drive shaft is coupled to the drive gear. The thermoplastic head is provided in the form of a plate with a plurality of holes for accommodating fasteners that couple the thermoplastic head to the distal end of the thermoplastic casing.

1 . An external gear pump comprising:
 a thermoplastic casing comprising a through bore for accommodating a drive shaft that leads to a pump chamber for accommodating a drive gear and a driven gear, the thermoplastic casing being coupled a stationary pin, the thermoplastic casing further comprising a proximal end coupled to a motor and a distal end coupled to a thermoplastic head,   the gears enclosed in the pump chamber by the thermoplastic head,   the stationary pin coupled to the driven gear, the drive shaft coupled to the drive gear,   the thermoplastic head consisting essentially of a plate with a plurality of holes for accommodating fasteners that couple the thermoplastic head to the distal end of the thermoplastic casing.   
     
     
         2 . The pump of  claim 1  wherein the fasteners are cap screws. 
     
     
         3 . The pump of  claim 1  wherein the through bore of the thermoplastic casing includes no bearings that engage the drive shaft. 
     
     
         4 . The pump of  claim 1  wherein the through bore of the thermoplastic casing and the drive shaft are sized so the through bore supports and provides a bearing function for the drive shaft without the use of an additional bearing. 
     
     
         5 . The pump of  claim 1  wherein the through bore comprises a distal end connected to the pump chamber and a proximal end connected to the proximal end of the thermoplastic casing, the proximal end of the through bore being recessed to accommodate a seal through which the drive shaft passes. 
     
     
         6 . The pump of  claim 1  wherein the distal end of the thermoplastic casing comprises a groove that encircles the pump chamber for accommodating a seal that is sandwiched between the distal end of the thermoplastic casing and the thermoplastic head. 
     
     
         7 . A deep fryer pump, the pump comprising:
 a thermoplastic casing comprising a through bore for accommodating a drive shaft and a pump chamber for accommodating a drive gear and a driven gear, the thermoplastic casing being coupled to a stationary pin, the thermoplastic casing further comprising a proximal end coupled to a motor and a distal end coupled to a thermoplastic head,   the gears enclosed in the pump chamber by the thermoplastic head,   the stationary pin coupled to the driven gear, the drive shaft coupled to the drive gear,   the thermoplastic head consisting essentially of a plate with a plurality of holes for accommodating fasteners that couple the thermoplastic head to the distal end of the thermoplastic casing.   
     
     
         8 . The deep fryer pump of  claim 7  wherein the fasteners are cap screws. 
     
     
         9 . The deep fryer pump of  claim 7  wherein the through bore of thermoplastic casing includes no bearings that engage the drive shaft. 
     
     
         10 . The deep fryer pump of  claim 7  wherein the through bore of the thermoplastic casing and the drive shaft are sized so the through bore supports and provides a bearing function for the drive shaft without the use of an additional bearing. 
     
     
         11 . The deep fryer pump of  claim 7  wherein the through bore comprises a distal end connected to the pump chamber and a proximal end connected to the proximal end of the thermoplastic casing, the proximal end of the through bore being recessed to accommodate a seal through which the drive shaft passes. 
     
     
         12 . The deep fryer pump of  claim 7  wherein the distal end of thermoplastic casing comprises a groove that encircles the pump chamber for accommodating a seal that is sandwiched between the distal end of the thermoplastic casing and the thermoplastic head. 
     
     
         13 . A deep fryer pump, the pump consisting essentially of:
 a casing consisting essentially of
 a through bore for accommodating a drive shaft, a pump chamber for accommodating a drive gear and a driven gear, 
 a recess connected to the pump chamber for accommodating a stationary pin, 
 a proximal end coupled to a motor, a distal end coupled to a thermoplastic head, and 
 a groove that encircles the pump chamber for accommodating a seal that is sandwiched between the distal end of the thermoplastic casing and the thermoplastic head, 
   the gears enclosed in the pump chamber by the thermoplastic head, the stationary pin coupled to the driven gear, the drive shaft coupled to the drive gear,   the thermoplastic head consisting essentially of a plate with a plurality of holes for accommodating fasteners that couple the thermoplastic head to the distal end of the thermoplastic casing, and   the through bore comprises a distal end connected to the pump chamber and a proximal end connected to the proximal end of the thermoplastic casing, the proximal end of the through bore being recessed to accommodate a seal through which the drive shaft passes   
     
     
         14 . The deep fryer pump of  claim 13  wherein the fasteners are cap screws. 
     
     
         15 . The deep fryer pump of  claim 13  wherein the through bore of the thermoplastic casing and the drive shaft are sized so the through bore supports and provides a bearing function for the drive shaft without the use of an additional bearing. 
     
     
         16 . The deep fryer pump of  claim 13  wherein the casing and head are fabricated from engineered thermoplastics. 
     
     
         17 . The deep fryer pump of  claim 16  wherein the pump is listed for use as a deep fryer oil pump by NSF.