Control valve supply for rotary hydraulic machine

A rotary hydraulic machine having a housing, a rotating group located within said housing and including a plurality of variable capacity chambers defined between pistons slideable within respective cylinders, said pistons being displaceable relative to said cylinders upon rotation of said barrel to vary the volume of said chambers and thereby induce a flow of fluid through said chambers from an inlet port to an outlet port as said rotating group rotates, an adjustment assembly including a pair of actuators operable upon said rotating group to adjust the stroke of said pistons in said cylinder and thereby adjust the capacity of said machine, a fluid supply for said actuators, and a control valve interposed between said fluid supply and said actuator to control flow to said actuators, said fluid supply including a pressurized fluid source, a hydraulic accumulator to store pressurized fluid from said source and apply stored fluid to said control valve and a check valve to inhibit flow from said accumulator to said source upon reduction of pressure at said source below that of said accumulator whilst maintaining the application of stored fluid to said control valve, each of said actuators being single acting and having a spring to bias respective ones to said actuators to a maximum capacity with one of said springs having a greater bias than the other to move said adjustment assembly to a position of maximum capacity in the absence of pressurized fluid at said control valve.