Hydraulic pump assembly

Abstract

A hydraulic pump assembly including a fluid reservoir, a body defining a fluid inlet and a fluid outlet, the fluid inlet being in fluid communication with the fluid reservoir, and a radially opposed piston pump assembly at least partially housed within the body and including a first piston pump mechanism and a second piston pump mechanism, the first piston pump mechanism being in fluid communication with the fluid inlet and having a first pump outlet, the second piston pump mechanism being in fluid communication with the fluid inlet and having a second pump outlet, wherein the first pump outlet and the second pump outlet are both in fluid communication with the fluid outlet.

1 . A hydraulic pump assembly comprising:
 a fluid reservoir;   a body defining a fluid inlet and a fluid outlet, said fluid inlet being in fluid communication with said fluid reservoir; and   a radially opposed piston pump assembly at least partially housed within said body and including a first piston pump mechanism and a second piston pump mechanism, said first piston pump mechanism being in fluid communication with said fluid inlet and having a first pump outlet, said second piston pump mechanism being in fluid communication with said fluid inlet and having a second pump outlet, wherein said first pump outlet and said second pump outlet are both in fluid communication with said fluid outlet.   
     
     
         2 . The hydraulic pump assembly of  claim 1  further comprising a pressure relief valve in fluid communication with said fluid outlet. 
     
     
         3 . The hydraulic pump assembly of  claim 2  wherein said pressure relief valve includes a biasing element that urges a ball into engagement with a valve seat. 
     
     
         4 . The hydraulic pump assembly of  claim 3  wherein said pressure relief valve further includes a pressure relief control screw, said biasing element being positioned between said ball and said pressure relief control screw. 
     
     
         5 . The hydraulic pump assembly of  claim 1  wherein said fluid reservoir includes a bottle and a cap, said cap sealingly engaging said bottle. 
     
     
         6 . The hydraulic pump assembly of  claim 1  wherein said radially opposed piston pump assembly includes a motor connected to said body, said motor having a shaft with an eccentric. 
     
     
         7 . The hydraulic pump assembly of  claim 6  wherein said eccentric operatively engages said first and said second piston pump mechanisms. 
     
     
         8 . The hydraulic pump assembly of  claim 6  wherein said motor is an electric motor. 
     
     
         9 . The hydraulic pump assembly of  claim 6  wherein said first piston pump mechanism includes a first piston biased into engagement with said eccentric and said second piston pump mechanism includes a second piston biased into engagement with said eccentric. 
     
     
         10 . The hydraulic pump assembly of  claim 1  further comprising a first pump inlet check valve positioned in a first fluid path within said body between said fluid reservoir and said first piston pump mechanism and a second pump inlet check valve positioned in a second fluid path within said body between said fluid reservoir and said second piston pump mechanism. 
     
     
         11 . The hydraulic pump assembly of  claim 1  further comprising a first pump outlet check valve positioned in a first fluid path within said body between said first piston pump mechanism and said first pump outlet and a second pump outlet check valve positioned in a second fluid path within said body between said second piston pump mechanism and said second pump outlet. 
     
     
         12 . The hydraulic pump assembly of  claim 1  further comprising a spool valve received within said body, said spool valve being disposed in a fluid channel between said fluid outlet and said first and second pump outlets. 
     
     
         13 . The hydraulic pump assembly of  claim 12  wherein said spool valve includes a first input/output and a second input/output, and wherein said spool valve is configurable between a first position, wherein said first input/output is in fluid communication with said fluid output, a second position, wherein said fluid output is decoupled from said first input/output and said second input/output, and a third position, wherein said second input/output is in fluid communication with said fluid output. 
     
     
         14 . The hydraulic pump assembly of  claim 1  wherein said first pump outlet and said second pump outlet are combined to form a combined pump outlet, said combined pump outlet being in fluid communication with a constant pressure outlet port and a variable pressure outlet port, and wherein a first normally closed solenoid actuated poppet valve is disposed in a first fluid line between said variable pressure outlet port and said combined pump outlet, said first normally closed solenoid actuated poppet valve being received, at least partially, within said body. 
     
     
         15 . The hydraulic pump assembly of  claim 14  further comprising a second normally closed solenoid actuated poppet valve disposed in a second fluid line between said variable pressure outlet port and said fluid reservoir, said second normally closed solenoid actuated poppet valve being received, at least partially, within said body. 
     
     
         16 . A hydraulic pump assembly comprising:
 a fluid reservoir;   a body defining a fluid inlet and a fluid outlet, said fluid inlet being in fluid communication with said fluid reservoir;   a radially opposed piston pump assembly at least partially housed within said body and including a first piston pump mechanism, a second piston pump mechanism and an electric motor, said electric motor including an eccentric that engages said first and said second piston pump mechanisms, said first piston pump mechanism being in fluid communication with said fluid inlet and having a first pump outlet, said second piston pump mechanism being in fluid communication with said fluid inlet and having a second pump outlet, wherein said first pump outlet and said second pump outlet are both in fluid communication with said fluid outlet;   a first pump inlet check valve positioned in a first inlet fluid path within said body between said fluid reservoir and said first piston pump mechanism;   a second pump inlet check valve positioned in a second inlet fluid path within said body between said fluid reservoir and said second piston pump mechanism;   a first pump outlet check valve positioned in a first outlet fluid path within said body between said first piston pump mechanism and said first pump outlet;   a second pump outlet check valve positioned in a second outlet fluid path within said body between said second piston pump mechanism and said second pump outlet; and   a pressure relief valve in fluid communication with said fluid outlet.   
     
     
         17 . The hydraulic pump assembly of  claim 16  wherein said pressure relief valve includes a biasing element that urges a ball into engagement with a valve seat, and a pressure relief control screw, said biasing element being positioned between said ball and said pressure relief control screw. 
     
     
         18 . The hydraulic pump assembly of  claim 16  wherein said fluid reservoir includes a bottle and a cap sealing engaged with said bottle. 
     
     
         19 . The hydraulic pump assembly of  claim 16  further comprising a three-position, bi-directional spool valve at least partially received in said body, said spool valve being in fluid communication with said fluid outlet. 
     
     
         20 . The hydraulic pump assembly of  claim 16  further comprising a normally closed solenoid actuated poppet valve at least partially received in said body, said solenoid actuated poppet valve being in fluid communication with said fluid outlet.