CPC F04B 49/03 (2013.01) [F04B 1/06 (2013.01); F04B 7/0076 (2013.01); F04B 49/022 (2013.01); F04B 49/06 (2013.01); F04B 49/065 (2013.01); F04B 49/08 (2013.01); F04B 49/24 (2013.01); F04B 51/00 (2013.01); F04B 53/10 (2013.01)] | 15 Claims |
1. A hydraulic machine comprising:
at least one working chamber with cyclically varying volume;
controllable high and low-pressure valves, arranged between a fluid source and the at least one working chamber and at least one fluid sink and the at least one working chamber, respectively, wherein the fluid source has high pressure and the at least one fluid sink has low pressure; and
a control system arranged to control opening and closing of said high and low-pressure valves,
wherein the control system is configured to:
operate the hydraulic machine in an empty cylinder idle mode; and
keep the high and low-pressure valves concurrently closed for at least a whole cycle of the varying volume,
wherein the hydraulic machine comprises a first idle safety valve arrangement arranged between the at least one working chamber and the at least one fluid sink with a pressure lower than the high pressure,
wherein the first idle safety valve arrangement is configured to release hydraulic fluid to the at least one fluid sink when it is enabled and if a fluid pressure in the at least one first working chamber increases above a set threshold,
wherein the control system is arranged to:
enable the first idle safety valve arrangement when the hydraulic machine operates in the empty cylinder idle mode; and
disable the first idle safety valve arrangement when the hydraulic machine does not operate in the empty cylinder idle mode.
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