A lift apparatus and method for driving a downhole reciprocating pump is disclosed and includes a hydraulic cylinder having a piston and a hydraulic fluid port, the piston being coupled to a rod for driving the reciprocating pump, the piston being moveable between first and second ends of the cylinder in response to a flow of hydraulic fluid through the hydraulic fluid port. A variable displacement hydraulic pump is responsive to a displacement control signal to draw hydraulic fluid from a reservoir and to produce a controlled flow of hydraulic fluid at the outlet. The apparatus also includes a valve connected between the hydraulic fluid port and the reservoir, the valve being responsive to a valve control signal for controlling discharge of hydraulic fluid from the hydraulic fluid port of the cylinder back to the reservoir to facilitate movement of the piston through a downstroke away from the second end toward the first end of the cylinder. The apparatus further includes a first sensor located proximate the first end of the cylinder and operable to produce a first signal indicating a proximity of the piston to the first sensor, a second sensor located proximate the second end of the cylinder and operable to produce a second signal indicating a proximity of the piston to the second sensor, and a controller operably configured to generate the displacement control signal and the valve control signal in response to receiving the first signal and the second signal.

A tilting angle control device includes pressure sensors. Each of the pressure sensors outputs to a control unit a pressure command signal corresponding to an operation amount. The control unit outputs to an electromagnetic proportional control valve a pressure control signal corresponding to the pressure command signal, and the electromagnetic proportional control valve outputs to a tilt adjustment mechanism pilot pressure corresponding to the pressure control signal. The tilt adjustment mechanism adjusts a tilting angle of a variable displacement pump such that the tilting angle becomes an angle corresponding to the pilot pressure. A pilot pressure sensor detects the pilot pressure to output a pressure feedback signal to the control unit. The control unit calculates the pressure control signal based on the pressure feedback signal and the pressure command signal and performs feedback control of the pilot pressure.

The invention relates to a clutch device for a drivetrain of a motor vehicle, including a pressure plate which is preferably displaceable in the axial direction of the clutch device, wherein the pressure plate, in a coupled position of the clutch device, presses a clutch disk against a counterpressure plate that can be connected to a crankshaft of an internal combustion engine, and including an actuating device which has a displaceable actuating piston. The displacement position of the actuating piston defines a position of the pressure plate and the actuating piston can be driven by a drive unit of the actuating device in order to displace the pressure plate between the coupled position and an uncoupled position. The drive unit has at least one pump, and the at least one pump is accommodated in a pump seat housing and the pump seat housing is connected to the counterpressure plate in such a way as to rotate therewith.

In an embodiment, a variable flow pump may include a swashplate rotatably driven by a driveshaft. The swashplate may be movable between a first and second tilt angle relative to the driveshaft. A piston pump may be reciprocatingly driven by the swashplate based upon, at least in part, the tilt angle of the swashplate. An actuator piston may be moveable between a first and second position based upon, at least in part, a downstream backpressure of a fluid pumped by the piston pump. An actuator assembly may be moveable between a first and second position based upon, at least in part, the position of the actuator piston. The actuator assembly may include a swashplate driver configured urge the swashplate between the first and second tilt angles, and a biasing driver configured to apply a force urging the swashplate into contact with the swashplate driver.

A fluid delivery system for an engine is disclosed. The fluid delivery system comprises a pump, a valve module, a motor, and a displacement control module. The pump is operatively coupled with an engine and is adapted to provide a flow of a fluid. The valve module is provided in fluidic communication with the pump to control the flow of the fluid. The motor is provided in fluidic communication with the valve module to receive the flow of the fluid and generate mechanical power. The displacement control module is provided in fluidic communication with the pump and the valve module and is provided downstream of the pump and upstream of the valve module. The displacement control module controls a displacement of the pump for maintaining a constant flow rate of the fluid from the pump based, at least in part, on an engine speed regardless of compressor load.

A variable displacement compressor having means for regulating the minimum inclination angle of a swash plate, a spring urging the swash plate in the inclination angle-increasing direction, and a spring urging the swash plate in the inclination angle-decreasing direction. The swash plate inclination angle is a as the sum of the urging forces of both springs is zero, when the drive shaft is not rotated; and, when the drive shaft is rotated, its inclination angle is b at which the sum of moments MS, MF is zero. Moment MS of rotational motion is based on selling the product of inertia in the variable-angle direction of the swash plate to decrease the inclination angle of the swash plate from a. Moment MF is based on the combined urging force of both springs set so that the inclination angle b is positioned at a minimum angle at maximum rotational speed.

A method for operating an axial piston machine of swashplate design, in which a swashplate is settable by means of an adjustment device, and in which a controlled variable of the axial piston machine is regulated by predetermining a manipulated variable. Under the assumption of a constant intended value of the controlled variable, a future profile of the controlled variable is ascertained using a model of the axial piston machine in which respective current values of at least one operating variable of the axial piston machine, which comprises the controlled variable, and a current value of the manipulated variable are taken into account. A value to be set for the manipulated variable is ascertained and set taking into account the future profile of the controlled variable.

A compressor includes a swash plate rotated with a drive shaft in a swash plate chamber, a link mechanism that changes an inclination angle of the swash plate, an actuator rotated integrally with the drive shaft, and an actuator control mechanism. The actuator includes a partitioning body fitted to the drive shaft in the swash plate chamber, a movable body that is coupled to the swash plate and moved relative to the partitioning body along the axis of the drive shaft, and a control pressure chamber, the pressure of which moves the movable body. The control mechanism changes the pressure of the control pressure chamber to move the movable body. The swash plate includes a fulcrum point, coupled to the link mechanism, and an action point, coupled to the movable body. The fulcrum point and the action point are located at opposite sides of the drive shaft.

A compressor includes a swash plate rotated with a drive shaft in a swash plate chamber, a link mechanism that changes an inclination angle of the swash plate, an actuator rotated integrally with the drive shaft, and an actuator control mechanism. The actuator includes a partitioning body fitted to the drive shaft in the swash plate chamber, a movable body that is coupled to the swash plate and moved relative to the partitioning body along the axis of the drive shaft, and a control pressure chamber, the pressure of which moves the movable body. The control mechanism changes the pressure of the control pressure chamber to move the movable body. The swash plate includes a fulcrum point, coupled to the link mechanism, and an action point, coupled to the movable body. The fulcrum point and the action point are located at opposite sides of the drive shaft.

A variable-displacement engine comprises an engine block, power shaft and rotating cylinder block. Pistons and connecting rods mounted in the cylinder block connect to a wobble plate having a rotating ring portion and non-rotating ring portion connected to allow relative rotation therebetween while constraining the portions to remain parallel. The wobble plate defines an inclination plane, pivot axis and wobble plate angle . A piston control mechanism includes axial lift, control lever supported by the lift and by an anchor bearing, and links connecting the control lever to the wobble plate. Axial movement of the lift changes the axial position of the control lever pivot and changes the control lever angle, in turn changing, via the connecting links, the wobble plate angle and the axial position of the wobble plate pivot axis. This changes the piston displacement of the engine while maintaining substantially constant compression ratio.