Methods and systems relating to improvements in reliability of fluid power actuators are disclosed. An exemplary fluid power actuator (300) comprises, an actuator body (305) having a cylindrical cavity (310), fitted with a first end cap (315) and a second end cap (320) at longitudinal ends, a piston (325) with a piston rod (330) disposed inside the cylindrical cavity (310), wherein the actuator (300) is characterised by, a hollow tie rod (335) in the cylindrical cavity (310), wherein the hollow tie rod (335) is for conveying a pressurised fluid into a volume (A) in the cylindrical cavity (310) between the second end cap (320) and the piston (325) for exerting a force on the piston (325) for a stroke or stroke reversal. The hollow tie rod 335 serves dual purpose of holding the pressure retaining components together, providing a flow path for the fluid enabling actuator stroking and stroke reversal.

A mobile apparatus with a fluid pressure-operated implement mounted at a distal end of a boom includes a connection apparatus for selectively rotating the implement about an actuator axis at the distal end of the boom. The connection apparatus includes a rotary actuator and a pressurized fluid circuit for delivery of pressurized fluid through the rotary actuator to the implement. The pressurized fluid circuit includes channels establishing a fluidic connection axially through the rotating shaft of the rotary actuator. The pressurized fluid circuit facilitates passage of pressurized fluid through an internal, protected environment to the implement.

An actuator comprising a housing, a piston driven member axially movable within the housing and being coupled to the housing by a first pin and ramp coupling such that axial movement of the piston driven member relative to the housing is accompanied by angular movement of the piston driven member relative to the housing. The actuator includes an output member constrained against axial movement relative to the housing and coupled to the piston driven member by a second pin and ramp coupling such that both axial and angular movement of the piston driven member drive the output member for angular movement relative to the housing.

A centering apparatus for bi-directionally pivotable hopper doors. The apparatus is coupled between a frame of a hopper car and a bell crank of a hopper door. The apparatus includes a housing with a piston extending from one end. An end of the piston within the housing includes a piston head. A pair of coil springs are disposed within the housing on opposite sides of the piston head and counteract one another to bias the piston head toward the center of the housing and thus bias the hopper door toward a closed state. In a second configuration the apparatus includes a double-acting actuator with a pair of independent piston assemblies. An actuation system coupled to the actuator maintains the actuator and an associated hopper door in a closed position in a normal state and returns the hopper door to the closed position upon a failure in the system.

A centering apparatus for bi-directionally pivotable hopper doors. The apparatus is coupled between a frame of a hopper car and a bell crank of a hopper door. The apparatus includes a housing with a piston extending from one end. An end of the piston within the housing includes a piston head. A pair of coil springs are disposed within the housing on opposite sides of the piston head and counteract one another to bias the piston head toward the center of the housing and thus bias the hopper door toward a closed state. In a second configuration the apparatus includes a double-acting actuator with a pair of independent piston assemblies. An actuation system coupled to the actuator maintains the actuator and an associated hopper door in a closed position in a normal state and returns the hopper door to the closed position upon a failure in the system.

A hydraulic rotary drive includes a first rotary drive element and at least two annular pistons connected to the first rotary drive element in a rotationally fixed manner and configured to be axially movable on the first rotary drive element between two end positions. Each annular piston has two annular spur serrations directed away from one another. The hydraulic rotary drive includes a second rotary drive element with ring type serrations that are complementary to the spur serrations of the annular pistons. The hydraulic rotary drive includes a control unit that is configured to control supply of hydraulic fluid to the annular pistons to cause a reciprocating movement of the annular pistons on a shaft in accordance with an operating signal. The hydraulic rotary drive includes a sensor arrangement communicatively coupled to the control unit and arranged to detect the positions of the annular pistons along respective sliding paths.

A hydraulic rotary drive includes a first rotary drive element and at least two annular pistons connected to the first rotary drive element in a rotationally fixed manner and configured to be axially movable on the first rotary drive element between two end positions. Each annular piston has two annular spur serrations directed away from one another. The hydraulic rotary drive includes a second rotary drive element with ring type serrations that are complementary to the spur serrations of the annular pistons. The hydraulic rotary drive includes a control unit that is configured to control supply of hydraulic fluid to the annular pistons to cause a reciprocating movement of the annular pistons on a shaft in accordance with an operating signal. The hydraulic rotary drive includes a sensor arrangement communicatively coupled to the control unit and arranged to detect the positions of the annular pistons along respective sliding paths.

An electrohydraulic system includes an output shaft, a hydraulic piston, and a preload device. The output shaft rotationally drives the valve and extends along a first axis. The hydraulic piston extends along a second axis perpendicular to the first axis, is actuated by a pressure medium, and rotates the output shaft. The preload device stores energy via preloading of an elastic element, which extends along a third axis, by a hydraulic cylinder and to transmit the energy to the output shaft in the event of a fault. The hydraulic piston is guided into first and second cylinder housings, and at least one of the cylinder housings is connected to the hydraulic cylinder. A check valve is arranged between the cylinder housing and the hydraulic cylinder, and is configured to decouple the preload device from the hydraulic piston, the blocking direction going from the hydraulic cylinder to the cylinder housing.

Embodiments of the invention provide an actuator (100) for a valve assembly. The actuator can include a yoke (146) with at least one bore (196), a first rod assembly (136), and a first slide member (148) seated within the at least one bore and pivotally connected to the first rod assembly. The yoke can be configured to rotate about a yoke axis (198) to actuate the valve assembly. The first rod assembly can be configured to move in a first direction transverse to the at least one bore and the yoke axis. The first slide member can be configured to slide telescopically within the at least one bore as the first rod assembly moves in the first direction to transmit torque to the yoke for actuation of the valve assembly.

The present invention relates broadly to a floor jack and a multi-component trunnion assembly that transfers motion of a power unit to the lifting arm of the jack. The end block may include one or more trunnions that are coupled to the block. The trunnions may engage and be coupled to one or more connection plates coupled to the lifting arm of the jack. A hydraulic power unit, including at least one piston may be coupled to the trunnion block for lifting the lifting arm of the jack.