Patent ID: 8108111

Claim:
A transmission comprising a first fluid working machine for connection to a prime mover, one or more second fluid working machines for connection to a mechanical load or loads and a fluid system linking the first and second working machines, the fluid system having a high-pressure side and a low-pressure side each connected to said first and all said second fluid working machines, and a fluid accumulator on the high-pressure side, and including a fluid reservoir and a fluid controller operable to admit fluid therefrom into the low-pressure side of the fluid system, and including a pressure control valve connected between the reservoir and the low-pressure side, for limiting the pressure level of the low-pressure side, wherein the second fluid working machines include chambers of variable volume having electronically controllable valves such that each of said chambers has pumping, motoring and idling modes of operation, and the second fluid working machines are operable to both source fluid to and sink fluid from each of said high-pressure side and said low-pressure side.