Fluid pump assembly

Abstract

A fluid pump assembly includes a double acting fluid cylinder and a pump. The fluid cylinder includes a housing, a piston reciprocally disposed within the housing, and a piston rod carrying the piston and extending from the housing. The piston rod has an end. A pump includes a pump body, a pressure loaded seal and a wiper seal. The pump body has a pump chamber and a rod port. The piston rod extends through the rod port and the end is positioned within the pump chamber. The pressure loaded seal is positioned within the rod port around the piston rod and has a pressure loaded end face toward the pump chamber. The wiper seal is positioned within the rod port around the piston rod on a side of the pressure loaded seal opposite from the pump chamber.

1 . A fluid pump assembly, comprising:
 a double acting fluid cylinder including a housing, a piston reciprocally disposed within said housing, and a piston rod carrying said piston and extending from opposite ends of said housing, said piston rod having a first end and a second end;   a first pump including a pump body, a pressure loaded seal and a wiper seal, said pump body having a pump chamber and a rod port, said piston rod extending through said rod port and said first end positioned within said pump chamber, said pressure loaded seal positioned within said rod port around said piston rod and having a pressure loaded end face toward said pump chamber, said wiper seal positioned within said rod port around said piston rod on a side of said pressure loaded seal opposite from said pump chamber; and   a second pump including a pump body, a pressure loaded seal and a wiper seal, said pump body having a pump chamber and a rod port, said piston rod extending through said rod port and said second end positioned within said pump chamber, said pressure loaded seal positioned within said rod port around said piston rod and having a pressure loaded end face toward said pump chamber, said wiper seal positioned within said rod port around said piston rod on a side of said pressure loaded seal opposite from said pump chamber.   
     
     
         2 . The fluid pump assembly of  claim 1 , wherein each of said first pump and said second pump are mounted directly to said fluid cylinder. 
     
     
         3 . The fluid pump assembly of  claim 1 , wherein said first pump and said second pump each include an inlet and a piston check, each said piston check selectively fluidly interconnecting a respective said inlet and said pump chamber. 
     
     
         4 . The fluid pump assembly of  claim 3 , wherein said piston checks are selectively actuated such that when one said piston check is opened, the other said piston check is closed. 
     
     
         5 . The fluid pump assembly of  claim 3 , wherein each said piston check is closed when said corresponding piston rod is in a compression stroke, and opened when said corresponding piston rod is in a return stroke. 
     
     
         6 . The fluid pump assembly of  claim 1 , wherein said pressure loaded end face is one of V-shaped and U-shaped in cross section. 
     
     
         7 . The fluid pump assembly of  claim 6 , wherein said seal is a chevron seal. 
     
     
         8 . The fluid pump assembly of  claim 1 , wherein said fluid cylinder is an air cylinder. 
     
     
         9 . A fluid pump assembly, comprising:
 a double acting fluid cylinder including a housing, a piston reciprocally disposed within said housing, and a piston rod carrying said piston and extending from said housing, said piston rod having an end; and   a pump including a pump body, a pressure loaded seal and a wiper seal, said pump body having a pump chamber and a rod port, said piston rod extending through said rod port and said end positioned within said pump chamber, said pressure loaded seal positioned within said rod port around said piston rod and having a pressure loaded end face toward said pump chamber, said wiper seal positioned within said rod port around said piston rod on a side of said pressure loaded seal opposite from said pump chamber.   
     
     
         10 . The fluid pump assembly of  claim 9 , wherein said piston extends from opposite ends of said housing and has a second end; and further including a second pump assembly having a pump body, a pressure loaded seal and a wiper seal, said pump body having a pump chamber and a rod port, said piston rod extending through said rod port and said second end positioned within said pump chamber, said pressure loaded seal positioned within said rod port around said piston rod and having a pressure loaded end face toward said pump chamber, said wiper seal positioned within said rod port around said piston rod on a side of said pressure loaded seal opposite from said pump chamber. 
     
     
         11 . The fluid pump assembly of  claim 9 , wherein said pump is mounted directly to said fluid cylinder. 
     
     
         12 . The fluid pump assembly of  claim 9 , wherein said pump includes an inlet and a piston check, said piston check selectively fluidly interconnecting said inlet and said pump chamber. 
     
     
         13 . The fluid pump assembly of  claim 12 , wherein said piston check is closed when said piston rod is in a compression stroke, and opened when said piston rod is in a return stroke. 
     
     
         14 . The fluid pump assembly of  claim 9 , wherein said pressure loaded end face is one of V-shaped and U-shaped in cross section. 
     
     
         15 . The fluid pump assembly of  claim 14 , wherein said seal is a chevron seal. 
     
     
         16 . The fluid pump assembly of  claim 9 , wherein said fluid cylinder is an air cylinder.