Patent ID: 6033188
Filing Date: 2000-03-07
Classification: F04B

Abstract:
A pump system comprising:a variable fluid displacement pump including a pump housing and a swashplate movably mounted in said pump housing for varying the fluid displacement of said pump;a servo having a hydraulically movable servo piston mechanically coupled to said swashplate;a pump pressure line fluidly connected to a fluid pressure load;a load sensing control operatively connected by said pump pressure line to said pump and by a load sensing signal line to said pressure load;a variable orifice located downstream from said pump and said load sensing control, said variable orifice being fluidly connected by a servo pressure conduit to the load sensing control such that the difference in the fluid pressure in said pump pressure line and the pressure sensed by said load sensing control varies proportionally in relation to the magnitude of the fluid displacement of said pump;the variable orifice being at least partially delimited by said servo piston such that said orifice is variable in size based upon movement of said servo piston and thereby controlled by mechanical feedback regarding the position of the swashplate.