Patent attributes
A low noise, high efficiency solenoid pump includes a housing containing a hollow electromagnetic coil. Within the coil resides a pump assembly defining a tubular body having a pair of opposed ends which respectively include an inlet or suction port and an outlet or pressure port and within which a plunger or piston resides. The piston is biased in opposite directions by a pair of opposed compression springs. A first compression spring limits and arrests travel of the piston during the suction or return stroke and a second compression spring limits travel of the piston during the pumping stroke and returns the piston after the pumping stroke. The piston includes a first check valve that opens to allow hydraulic fluid into a pumping chamber during the suction stroke and closes during the pumping stroke to cause fluid to be pumped out of the pumping chamber. A second check valve opens to allow pumped fluid to exit the pumping chamber and the pump body through the outlet or pressure port and closes to inhibit reverse flow.