An actuator system includes a piston-cylinder arrangement including a piston that is movable with respect to a cylinder. A first flow path is in fluid communication with the piston-cylinder arrangement and a second flow path is in fluid communication with the piston-cylinder arrangement. A control system is operable to fluidly connect the first flow path to a source of high-pressure fluid and to connect the second flow path to a drain to move the piston in a first direction. A pressure sensor is fluidly connected to the first flow path and is operable to measure sufficient pressure data during the movement of the piston to generate a pressure versus time curve. The control system is operable to compare the generated pressure versus time curve to a known standard pressure versus time curve stored in the control system to determine the condition of the piston-cylinder arrangement.

An actuator system includes a piston-cylinder arrangement including a piston that is movable with respect to a cylinder. A first flow path is in fluid communication with the piston-cylinder arrangement and a second flow path is in fluid communication with the piston-cylinder arrangement. A control system is operable to fluidly connect the first flow path to a source of high-pressure fluid and to connect the second flow path to a drain to move the piston in a first direction. A pressure sensor is fluidly connected to the first flow path and is operable to measure sufficient pressure data during the movement of the piston to generate a pressure versus time curve. The control system is operable to compare the generated pressure versus time curve to a known standard pressure versus time curve stored in the control system to determine the condition of the piston-cylinder arrangement.

A track-type loader machine includes a main frame, laterally spaced track roller frames, an equalizer bar pivotally mounted to the main frame and attached to the roller frames, a work implement movably connected to the main frame by a plurality of linkages, and at least one cross-slope actuator which connects one of the roller frames to the main frame. The at least one cross-slope actuator is configured to tilt the work implement and the plurality of linkages in conjunction with the main frame relative to a pivoting axis of the equalizer bar.

A track-type loader machine includes a main frame, laterally spaced track roller frames, an equalizer bar pivotally mounted to the main frame and attached to the roller frames, a work implement movably connected to the main frame by a plurality of linkages, and at least one cross-slope actuator which connects one of the roller frames to the main frame. The at least one cross-slope actuator is configured to tilt the work implement and the plurality of linkages in conjunction with the main frame relative to a pivoting axis of the equalizer bar.

An actuator includes a housing defining an inlet port, a piston and a return spring disposed within the housing, and an elastically deformable element. The return spring is configured to apply a biasing force to the piston to move the piston to a spring return position. A first fluid pressure applied to the inlet port moves the piston against the biasing force of the return spring to a first actuated position in which the piston indirectly engages a stop portion of the actuator housing. A second fluid pressure, greater than the first fluid pressure, applied to the inlet port moves the piston against the elastically deformable element to compress the elastically deformable element to move the piston to a second actuated position beyond the first actuated position.

A robot device of the present disclosure includes at least one artificial muscle that operates by being supplied with liquid; and a liquid supply device that supplies and discharges the liquid to/from the artificial muscle, and the liquid supply device includes a liquid storage part that stores the liquid; a pump that sucks the liquid from the liquid storage part and discharges the liquid; a pressure regulating device that includes a spool and an electromagnetic part that allows the spool to move, and that generates drive pressure for the artificial muscle by regulating source pressure from the pump side, and regulates the source pressure by balancing at least a force given to the spool from the electromagnetic part and a force given to the spool by action of the drive pressure; and a control device that applies a current to the electromagnetic part of the pressure regulating device so that the drive pressure reaches target pressure.

A robot includes elbows connecting forearms rotatably to upper arms with two rotational degrees of freedom. The elbow includes: an elbow joint connecting the forearm and the upper arm with two rotational degrees of freedom; an elbow drive main link; an elbow drive auxiliary link; a forearm-side main link attaching unit attached with one end of the elbow drive main link with two rotational degrees of freedom, and provided in the forearm; an elbow-drive-main-link-side auxiliary link attaching unit attached with one end of the elbow drive auxiliary link with two rotational degrees of freedom, and provided on the elbow drive main link; and two linear actuators for moving two upper-arm-side link attaching units each attached with the other end of either the elbow drive main link or the elbow drive auxiliary link with two rotational degrees of freedom, and provided so as to be movable along the upper arm.

A robot includes elbows connecting forearms rotatably to upper arms with two rotational degrees of freedom. The elbow includes: an elbow joint connecting the forearm and the upper arm with two rotational degrees of freedom; an elbow drive main link; an elbow drive auxiliary link; a forearm-side main link attaching unit attached with one end of the elbow drive main link with two rotational degrees of freedom, and provided in the forearm; an elbow-drive-main-link-side auxiliary link attaching unit attached with one end of the elbow drive auxiliary link with two rotational degrees of freedom, and provided on the elbow drive main link; and two linear actuators for moving two upper-arm-side link attaching units each attached with the other end of either the elbow drive main link or the elbow drive auxiliary link with two rotational degrees of freedom, and provided so as to be movable along the upper arm.

A hydraulic drive system includes control valve and operating devices, a variable displacement pump, and a flow regulator. When an operating lever inclination angle becomes a value, a control valve opening area becomes a reference. When the operating lever inclination angle maximizes, the opening area maximizes. The flow regulator: until the operating lever inclination angle becomes the value, increases the pump discharge flow rate with the inclination angle, so a differential pressure between pump discharge and actuator load pressures is constant; when the operating lever inclination angle becomes the value, controls the pump discharge flow rate, so a control valve passing flow rate is an actuator maximum flow rate when the differential pressure is constant; and when the operating lever inclination angle is between the value and the maximum, defines a maximum pump discharge flow rate, so the pump discharge flow rate is kept to the actuator maximum flow rate.

A hydraulic drive system includes control valve and operating devices, a variable displacement pump, and a flow regulator. When an operating lever inclination angle becomes a value, a control valve opening area becomes a reference. When the operating lever inclination angle maximizes, the opening area maximizes. The flow regulator: until the operating lever inclination angle becomes the value, increases the pump discharge flow rate with the inclination angle, so a differential pressure between pump discharge and actuator load pressures is constant; when the operating lever inclination angle becomes the value, controls the pump discharge flow rate, so a control valve passing flow rate is an actuator maximum flow rate when the differential pressure is constant; and when the operating lever inclination angle is between the value and the maximum, defines a maximum pump discharge flow rate, so the pump discharge flow rate is kept to the actuator maximum flow rate.