Multi-purpose hydraulic negative-feedback pump

The invention supplies a kind of hydraulic degenerative feedback multi-purpose pump, which has oil tank, pump electric engines, leading regulating valve, flow regulating valve, high-pressure sucker and oil return pipe. High-pressure sucker is connected with the fast changement and negative feedback oil cylinder, both oil circuits of which are connected. Fast changement is made up of pilot two-position four-way valve and two fast jumping valves on both terminals. Negative feedback oil cylinder is connected with cylinder body and inner negative feedback plunger. There is return chute along inwall top roll of spool chamber's both sides of pilot two-position four-way valve. There are upper negative feedback canal and lower negative feedback canal on both sides of negative feedback oil cylinder body, and two negative feedback canals are connected with fast jumping valve. Compared with existing technology, it has compact structure, small capacity and low cost, which can realize output of HF reciprocating commutation and large power, and have good energy-saving effect.