Patent ID: 9638188
Date: 2017-05-02
CPC Classifications: F01C,F04C,Y10T

Claim:
1. A hydraulic assembly, comprising: a first hydraulic pump; a second hydraulic pump coupled together with the first hydraulic pump, the second hydraulic pump including: a rotor mounted within the chamber, the chamber and the rotor being shaped to define one or more rise regions, fall regions, and dwell regions between the walls of the chamber and the rotor, the rotor including; a plurality of slideable vanes, a plurality of slots within the rotor, each configured to accept a corresponding one of the plurality of slidable vanes, wherein each slot in the plurality of slots includes a selectable vane retainer movable between a first position to lock a vane in a retracted vane position, and a second position to allow the vane to move freely within the slot; wherein each slot in the plurality of slots includes an under vane passage in fluid communication with pressurized fluid, such that when the selectable vane retainer is in the second position, the vane is driven to an extended position by the pressurized fluid, and a control system for controlling operating of the second hydraulic pump, the control system including a spool valve having a first end portion configured to detect a first pressure in an outlet line from the first hydraulic pump prior to a flow orifice, the spool valve including a second end portion configured to detect a second pressure in the outlet line from the first hydraulic pump after the flow orifice.