HYDRAULICALLY OPERATED PUMP Russian patent published in 1995 - IPC

FIELD: pump engineering. SUBSTANCE: housing is separated into driving and working chambers of the engine and pump by cross-pieces. Pistons mounted on the common rod are received in the chambers. Valving unit of the feeding chamber of the engine is received in a sleeve. An additional chamber is defined by the housing bottom and working chamber of the pump. The additional chamber is separated from the working chamber by the additional cross-piece. One end of the rod is received in this chamber and the other one is received in the feeding chamber. The rod is provided with a passage and spring-loaded with adjusting spring with respect to the housing bottom. The unit has a sleeve provided with two projections. Springs are interposed between the projections for alternative interaction with the bottom of the sleeve and the top face of the rod. A step recess is made in the bottom part of the sleeve. The recess and the top projection can define a brake space. There is a passage in the wall of the sleeve directed from the recess bottom to the feeding chamber. A float ring is interposed between the passage and brake space for periodic connection of the space with the feeding chamber. EFFECT: enhanced efficiency. 3 dwg