A fluid system includes a variable-speed and/or a variable-torque pump to pump a fluid, at least one proportional control valve assembly, an actuator that is operated by the fluid to control a load, and a controller that establishes a speed and/or torque of the pump and a position of the at least one proportional control valve assembly. The pump includes at least one fluid driver that provides fluid to the actuator, which can be, e.g., a fluid-actuated cylinder, a fluid-driven motor or another type of fluid-driven actuator that controls a load. Each fluid driver includes a prime mover and a fluid displacement assembly. The fluid displacement assembly can be driven by the prime mover such that fluid is transferred from the inlet port to the outlet port of the pump.

A baler connectable to a tractor for providing round bales comprises: a frame supported on a wheel axle; a chamber, for receiving crops and for housing a formed bale, the chamber having a fixed, predetermined size; a tailgate connected to the frame and movable between a closed position and an open position; a conveying assembly which has a first portion provided in the frame and a second portion provided in the tailgate; a cylinder-piston actuator, which includes a closing chamber and moves the tailgate from the open position to the closed position; a binder, configured for binding the formed bale with a fastening element; a pressure sensor for detecting a control signal representative of a pressure inside the closing chamber of the cylinder-piston actuator; a control unit, configured to generate an alert signal as a function of the control signal.

A fluid system includes a variable-speed and/or a variable-torque pump to pump a fluid, at least one proportional control valve assembly, an actuator that is operated by the fluid to control a load, and a controller that establishes a speed and/or torque of the pump and a position of the at least one proportional control valve assembly. The pump includes at least one fluid driver that provides fluid to the actuator, which can be, e.g., a fluid-actuated cylinder, a fluid-driven motor or another type of fluid-driven actuator that controls a load. Each fluid driver includes a prime mover and a fluid displacement assembly. The fluid displacement assembly can be driven by the prime mover such that fluid is transferred from the inlet port to the outlet port of the pump.

A system for detecting leaks in a hydraulic supply system for a double-acting hydraulic actuator is disclosed. The system may include a first conduit in fluid communication with a first chamber of the actuator, and with a second chamber of the actuator, and a directional control valve coupled with the first conduit and the second conduit. A directional control valve may be in fluid communication with a hydraulic oil supply line and may switch between the hydraulic oil being sent and received via the first conduit and second conduit. A valve can be associated with the oil supply line. A first and second flow meter can generate a first signal and a second signal, respectively, indicating flow rate within the first conduit and the second conduit. A controller may receive the first signal and the second signal, calculate their ratio, and cause the valve to inhibit flow within the oil supply line upon the ratio differing from a given ratio by more than a predetermined threshold.

A pilot pressure supply solenoid valve (36) is disposed in a flow path connecting an inlet port (16) and a pilot chamber (48), and a pilot pressure discharge solenoid valve (38) is disposed in a flow path through which a pressure fluid in the pilot chamber is discharged to the exterior. A flow path, through which the pressure fluid that has passed through a supply valve (26) is discharged to the exterior, is not provided.

Provided is a slewing drive apparatus for a construction machine capable of satisfactory pump-flow-rate control regardless of change in engine speed, including a variable displacement hydraulic pump, a slewing motor, a slewing operation device, a control valve, a relief valve, and a pump-flow-rate control device that performs a relief cut control and includes: a section for detecting an engine revolution number Ne and a slewing speed of a slewing body; a section for determining a target pump flow rate Qo that is a sum of a slewing-speed correspondence flow rate Q1 and a minimum required relief flow rate Qmin; a section for determining a target pump-tilt-angle qtg obtained by dividing the target pump flow rate Qo by the detected engine revolution number Ne; and a section for adjusting an actual pump-tilt-angle of the hydraulic pump so as to bring the actual pump-tilt-angle to the target pump-tilt-angle qtg.

This disclosure includes systems and methods for actuating hydraulically-actuated devices.

A hydraulic system (600) and method for reducing boom dynamics of a boom (30), while providing counter-balance valve protection, includes a hydraulic actuator (110), first and second counter-balance valves (300, 400), first and second independent control valves (700, 800), and first and second blocking valves (350, 450). The actuator includes first and second corresponding chambers. In a first mode, the second counter-balance valve is opened by the first control valve, and the first counter-balance valve is opened by the second control valve. In a second mode, at least one of the counter-balance valves is closed. A meter-out control valve (800, 700) may be operated in a flow control mode, and/or a meter-in control valve (700, 800) may be operated in a pressure control mode. Boom dynamics reduction may occur while the boom is in motion (e.g., about a worksite). By opening the counter-balance valves, sensors at the control valves may be used to characterize external loads. The control valves may respond to the external loads and at least partially cancel unwanted boom dynamics. The system may further detecting faults in actuators with counter-balance valves and prevent any single point fault from causing a boom falling event and/or mitigate such faults.

Examples of automatic valve shutoff systems are described which may include an actuation device including an actuator and a valve attachment portion. The valve attachment portion may be configured for attachment with an existing valve in a fluid or compressible gas supply line. The system may further include a controller coupled to the actuation device, wherein the controller is configured to initiate a valve shutoff process in response to a wireless signal. Wake-up circuitry may be coupled to the controller and configured to monitor the supply line for vibrations and activate the controller in response to the vibrations.

A linear actuator system includes a linear actuator and at least one integrated pump assembly connected to the linear actuator to provide fluid to operate the linear actuator. The integrated pump assembly includes a pump with at least one fluid driver comprising a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from a first port of the pump to a second port of the pump. The pump assembly also includes two valve assembles to isolate the pump from the system. The linear actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover to exclusively adjust at least one of a flow and a pressure in the linear actuator system to an operational set point.