Patent ID: 9739266
Date: 2017-08-22
CPC Classifications: F03B,F03D,F05B,Y02E

Claim:
1. A method of operating a fluid-working machine comprising a plurality of working chambers of cyclically varying volume, each said working chamber operable to displace a volume of working fluid which is selectable for each cycle of working chamber volume, the method comprising: selecting the volume of working fluid displaced by one or more said working chambers during each cycle of working chamber volume, and displacing, by one or more said working chambers, the selected volume of working fluid to carry out a working function responsive to a received demand signal, wherein selecting the volume of working fluid displaced by a first working chamber during a cycle of working chamber volume takes into account suitability of said first working chamber to displace fluid to carry out the working function, and the suitability which is taken into account is selected from the group consisting of (a) a parameter determined by a historical amount of use of the one or more working chambers, (b) a parameter determined by a measurement or prediction of a net force applied to a rotatable shaft of said fluid-working machine by fluid-pressurized working chambers, and (c) a parameter determined responsive to measuring or predicting a motion of a mechanical component, said motion being influenced by said fluid-working machine, wherein said selecting the volume of working fluid displaced by the first working chamber during the cycle of working chamber volume further takes into account the relative suitability of at least one second working chamber to displace fluid to carry out the working function, wherein each working chamber is operable on each cycle of working chamber volume to carry out an active cycle in which the chamber makes a net displacement of working fluid or an idle cycle in which the chamber makes substantially no net displacement of working fluid, and wherein, on at least one occasion, the first working chamber carries out an active cycle instead of an idle cycle as a result of the unsuitability of the second working chamber.