Abstract: A hydraulic system for a machine is disclosed. The system may have a pump and a motor driven by pressurized fluid from the pump. An accumulator is configured to receive fluid discharged from the motor and to discharge fluid to the motor. The system may include a first valve to selectively communicate the higher pressure of conduits coupled between the pump and motor to the accumulator. A second valve and a third valve can be used to facilitate charging and discharging of the accumulator. The system may include a controller configured to implement a plurality of modes of operation, which each mode of operation may include a different combination of motor deceleration and motor acceleration segments during which the accumulator receives and discharges fluid, respectively. An input may be used to determine the segment of the work cycle.

Abstract: A hydraulic system for a machine is disclosed. The system may have a pump and a motor driven by pressurized fluid from the pump. An accumulator is configured to receive fluid discharged from the motor and to discharge fluid to the motor. The system may include a first valve to selectively communicate the higher pressure of conduits coupled between the pump and motor to the accumulator. A second valve and a third valve can be used to facilitate charging and discharging of the accumulator. The system may include a controller configured to implement a plurality of modes of operation, which each mode of operation may include a different combination of motor deceleration and motor acceleration segments during which the accumulator receives and discharges fluid, respectively. An input may be used to determine the segment of the work cycle.

Abstract: A system and method to diagnose the operational health of a hydraulic accumulator are provided. The system can include a hydraulic accumulator selectively coupled to a hydraulic actuator, such as a swing motor. The accumulator can be charged by movement of the actuator. A pressure sensor can be associated with the accumulator to determine an accumulator pressure. A controller can be connected to the pressure sensor. The controller can determine a charge curve based on a relationship between an actuator operational parameter associated with the actuator movement and the accumulator pressure. The controller can compare the charge curve to a previously defined charge curve or range to determine an error between the charge curve and the previously defined charge curve or range. The degree of the error can be associated with the operational health of the accumulator, and if too large, the operator may be notified of the status.