| 主权项 |
1. An apparatus for pumping fluid, comprising:
a pair of rotatable intermeshed gears, each gear including a shaft, each gear being located along the corresponding shaft, said gear pair being adapted and configured to simultaneously provide fluid at a higher pressure and fluid at a lower pressure; a pair of substantially identical bearing blocks, each bearing block including a pair of journal bearings, each journal of a bearing block supporting a corresponding shaft of said gear pair, said gear pair being located between said bearing blocks; a casing defining an interior cavity that contains said gears and said bearing blocks, said casing having a pair of opposing end faces; a pair of cover plates, each said cover plate having a face (R1, R6) being opposite of a face (R2, R5) of a corresponding bearing block; and a pair of face seals, each said face seal having an outer periphery located between one said cover plate and a corresponding end face and an inner periphery located between said same cover plate and a corresponding bearing block, the area between the inner periphery and the outer periphery being divided into first and second lateral regions (A, C) each being laterally adjacent and outboard of the gear pair and two end regions (B, D) each being outboard of a single corresponding gear of said pair; wherein rotation of said gear pair in a first direction provides higher pressure fluid to the first lateral region and lower pressure fluid to the second lateral region, and rotation of said gear pair in a second direction opposite of said first direction provides higher pressure fluid to the second lateral region and lower pressure fluid to the first lateral region, each end region being provided with higher pressure fluid for rotation in either the first or second directions. |
