Inventors:
Thomas B. Martin - Pleasant Hill CA
Assignee:
Micropump Corporation - Concord CA
International Classification:
F04B 1700, F01C 118, F01C 1910, F04C 108
Abstract:
A pump has a block and a cup-like member having a rim engaging the block to define a pump cavity. Recessed into the block and opening or extending into the cavity are an inlet and an outlet duct and three parallel pins. The drive and driven gears are mounted on two of the pins, one face of each gear being tight against the block, and the two ducts are on opposite sides of the mesh point of the gears. A shoe is mounted on the third pin and overlies the inlet duct and the mesh point of the gears plus about two teeth to either side of the mesh point. A spring biases the shoe into contact with portions of the gears and the block to define a pump chamber. After a differential between the inlet and outlet duct pressures is established, this differential supplements the spring. One means of driving the drive gear comprises a motor driven annular magnet on the outside of the cup-like member and a smaller magnet within the cup-like member drivingly connected to the drive gear.