Patent ID: 6171089
Filing Date: 2001-01-09
Classification: F04C

Abstract:
A metering pump, comprising:a first circular gear having external gear teeth around the periphery thereof, said first gear having a central opening to receive a drive shaft and being rotatable by said drive shaft around a first axis;a second circular gear having external gear teeth around the periphery thereof, said second gear rotatable around a second axis;a housing including first and second housing plates enclosing the first and second gears, one of the housing plates having a central opening aligned with the central opening in the first gear, and the first and second housing plates having inner wall surfaces closely adjacent opposite side surfaces of the first and second gears, said first and second gears being rotatably supported within the housing such that the axis of the gears are parallel to one another and certain of the gear teeth of the two gears mesh together within a gear teeth chamber when the gears rotate;a first port in the housing providing an inlet fluid flow to an inlet discharge groove in the inner wall of the first housing plate and into the gear teeth chamber to provide fluid to an inlet side of the meshing gear teeth, and a second port in the housing providing an outlet fluid flow from an outlet discharge groove in the inner wall of the second housing plate from the gear teeth chamber to direct fluid from an outlet side of the meshing teeth, a centerline defined between the geometric axis of the first gear and the geometric axis of the second gear, where the inlet discharge groove is located on one side of the centerline, and an inlet pressure balancing groove in the inner wall of the first housing plate is located symmetrically on another side of the centerline for pressure balancing purposes, and where the outlet discharge groove is located on the other side of the centerline, and an outlet pressure balancing groove in the inner wall of the second housing plate is located symmetrically on the one side of the centerline for pressure balancing purposes, andan annular resilient sealing element disposed against each side surface of the first gear, surrounding the central opening in the first gear and fluidly sealing to the respective surfaces of the first gear during rotation of the gears to prevent fluid leakage into the central opening of the first gear.