| 摘要 |
Apparatus for adjusting the volume of fluid flow produced by a stroke of a piston pump, comprising a cylinder 100 communicating with an outlet of the pump, a plunger 98 for displacing fluid to the outlet and a piston 122 moveable in the cylinder, a port 120 opened and closed by the piston, a source of fluid supplied to the cylinder and a stop 116 for limiting the movement of the piston towards and away from the plunger. The position of the piston controls the internal volume of the cylinder between the piston and the plunger, the position of the piston being controlled by the amount of fluid entering the cylinder through the port behind the piston. The apparatus may have check valves 102 and 104 for opening and closing the pump inlet and outlet respectively. Independently claimed is a method of controlling a hydraulic pump driven by an internal combustion engine to reduce the load on the engine during staff-up which comprises providing the pump with a variable stroke lost motion piston. |
