Patent ID: 8244446

Claim:
A hydraulic circuit for recovering energy, which circuit comprises at least one hydraulic motor suitable for being declutched or for being clutched by fluid pressure, two main ducts for feeding fluid to or discharging fluid from said at least one motor, a low-pressure fluid source, a high-pressure accumulator forming a high-pressure source, and valve arrangement suitable for taking up an energy recovery configuration in which said valve arrangement respectively connects the feed main duct to the low-pressure fluid source and connects the discharge main duct to the high-pressure accumulator, and an energy delivery configuration in which said valve arrangement respectively connects the feed main duct to the high-pressure accumulator and connects the discharge main duct to the low-pressure fluid source, the valve arrangement comprising a hydraulic valve comprising firstly a valve body having a feed port connected to the feed main duct, a discharge port connected to the discharge main duct, a low-pressure link port connected to the low-pressure fluid source, a high-pressure link port connected to the high-pressure accumulator, and an auxiliary port, and secondly a slide suitable for taking up, inside the body, a neutral position in which the feed port and the discharge port communicate with each other and with the auxiliary port, an energy recovery position in which the feed port is connected to the low-pressure link port while the discharge port is connected to the high-pressure link port, and an energy delivery position in which the feed port is connected to the high-pressure link port while the discharge port is connected to the low-pressure link port, and the hydraulic circuit further being suitable for causing the slide to move from the neutral position thereof towards the energy recovery position thereof on receiving a first control signal, for causing the slide to move from the neutral position thereof towards the energy delivery position thereof on receiving a second control signal, and for causing the auxiliary port to be connected to a pressure-free enclosure or to a clutch fluid source for clutching the hydraulic motor on receiving a selection signal.