Abstract: A crescent internal gear pump includes a front cover, an end cover, a ring gear and a pinion gear disposed within a gear housing in an eccentric, intermeshing relationship. The housing is disposed intermediate the front cover and the end cover. A crescent is disposed radially intermediate the ring gear and the pinion gear. The crescent partially extends into a correspondingly shaped slot in the end cover. The gear housing, the ring gear, and the pinion gear can have substantially the same thickness. A shim can be disposed intermediate the end cover and the gear housing for establishing a desired clearance therebetween.

Abstract: A crescent internal gear pump includes a front cover, an end cover, a ring gear and a pinion gear disposed within a gear housing in an eccentric, intermeshing relationship. The housing is disposed intermediate the front cover and the end cover. A crescent is disposed radially intermediate the ring gear and the pinion gear. The crescent partially extends into a correspondingly shaped slot in the end cover. The gear housing, the ring gear, and the pinion gear can have substantially the same thickness. A shim can be disposed intermediate the end cover and the gear housing for establishing a desired clearance therebetween.

Abstract: A crescent internal gear pump includes a front cover, an end cover, a ring gear and a pinion gear disposed within a gear housing in an eccentric, intermeshing relationship. The housing is disposed intermediate the front cover and the end cover. A crescent is disposed radially intermediate the ring gear and the pinion gear. The crescent partially extends into a correspondingly shaped slot in the end cover. The gear housing, the ring gear, and the pinion gear can have substantially the same thickness. A shim can be disposed intermediate the end cover and the gear housing for establishing a desired clearance therebetween.

Abstract: A crescent internal gear pump includes a front cover, an end cover, a ring gear and a pinion gear disposed within a gear housing in an eccentric, intermeshing relationship. The housing is disposed intermediate the front cover and the end cover. A crescent is disposed radially intermediate the ring gear and the pinion gear. The crescent partially extends into a correspondingly shaped slot in the end cover. The gear housing, the ring gear, and the pinion gear can have substantially the same thickness. A shim can be disposed intermediate the end cover and the gear housing for establishing a desired clearance therebetween.

Abstract: A fluid pump configured to prevent contact between volatile fluids and a ball bearing of the pump while providing the ball bearing with adequate lubrication. The fluid pump includes a pump casing having a fluid inlet and a fluid outlet, and a rotor set disposed within the pump casing for conveying fluid from the fluid inlet to the fluid outlet. The fluid pump further includes a recirculation chamber located adjacent the fluid outlet for collecting leaked fluid. The leaked fluid may be conveyed from the recirculation chamber back to the fluid inlet due to a pressure differential therebetween. The fluid pump may further include first and second seals that surround a drive shaft of the rotor, the first and second fluid seals defining a lubricant chamber therebetween that houses a ball bearing of the pump and that is filled with a continuously circulated, nonvolatile lubricant.

Abstract: A self-adjusting gear pump is disclosed. The pump may be a crescent internal gear pump, a gerotor pump, or an external gear pump. The pump includes a pump housing, gear housing, first and second gears, a side plate housing with a side plate, a shim and an end plate. The side plate moves between a first position contacting the first and second gears and gear housing, and a second position contacting the end plate. The side plate is spring biased toward the first position. A method is disclosed for match grinding the crescent plate (if used), gear housing and gears as a unit to provide a uniform surface. The side plate housing and side plate are similarly match ground. An assembly method is disclosed which allows the crescent plate to be moved with respect to the gear housing so that clearances between the crescent and the gear teeth are eliminated.

Abstract: A fluid pump configured to prevent contact between volatile fluids and a ball bearing of the pump while providing the ball bearing with adequate lubrication. The fluid pump includes a pump casing having a fluid inlet and a fluid outlet, and a rotor set disposed within the pump casing for conveying fluid from the fluid inlet to the fluid outlet. The fluid pump further includes a recirculation chamber located adjacent the fluid outlet for collecting leaked fluid. The leaked fluid may be conveyed from the recirculation chamber back to the fluid inlet due to a pressure differential therebetween. The fluid pump may further include first and second seals that surround a drive shaft of the rotor, the first and second fluid seals defining a lubricant compartment therebetween that houses a ball bearing of the pump and that is filled with a continuously circulated, nonvolatile lubricant.

Abstract: A self-adjusting gear pump is disclosed. The pump may be a crescent internal gear pump, a gerotor pump, or an external gear pump. The pump includes a pump housing, gear housing, first and second gears, a side plate housing with a side plate, a shim and an end plate. The side plate moves between a first position contacting the first and second gears and gear housing, and a second position contacting the end plate. The side plate is spring biased toward the first position. A method is disclosed for match grinding the crescent plate (if used), gear housing and gears as a unit to provide a uniform surface. The side plate housing and side plate are similarly match ground. An assembly method is disclosed which allows the crescent plate to be moved with respect to the gear housing so that clearances between the crescent and the gear teeth are eliminated.