摘要:
The present invention provides a controller for a hydraulic apparatus. The controller is configured to determine (410) that a mode change criteria has been met for the hydraulic apparatus. In response to the determination, the controller is configured to control (420) a valve arrangement to change a first actuator chamber of a hydraulic actuator between being fluidly connected to a hydraulic machine and fluidly isolated from a second chamber of the hydraulic actuator, and being fluidly connected to both the second actuator chamber and the hydraulic machine. Further in response to the determination, the controller is configured to control (430) the hydraulic machine to change a flow rate of hydraulic fluid flowing through the hydraulic machine to regulate a movement of the hydraulic actuator during the control of the valve arrangement.
摘要:
An example valve assembly includes a housing having an accumulator fluid passage configured to be fluidly coupled to an accumulator, a supply fluid cavity configured to be fluidly coupled to a source of fluid, a reservoir fluid cavity configured to be fluidly coupled to a reservoir of fluid, a head fluid cavity configured to be fluidly coupled to a head-side chamber of a hydraulic actuator, and a rod fluid cavity configured to be fluidly coupled to a rod-side chamber of the hydraulic actuator; a main spool that is axially-movable within the housing; and a balancing spool that is axially-movable within the housing based on an axial position of the main spool.
摘要:
A linear actuator system includes a linear actuator and at least one proportional control valve and at least one pump connected to the linear actuator to provide fluid to operate the linear actuator. The at least one pump includes at least one fluid driver having a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from the pump inlet to the pump outlet. 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 and concurrently establishes an opening of the at least one proportional control valve to adjust at least one of a flow and a pressure in the linear actuator system to an operational set point.
摘要:
A hydraulic system is disclosed for use with a machine. The hydraulic system may have a closed-loop, meterless hydraulic circuit with a first pump fluidly connected to a first actuator. The hydraulic system may also have a closed-loop, metered hydraulic circuit with a second pump fluidly connected to a second actuator. The hydraulic system may further have a combiner valve configured to selectively direct fluid from the closed-loop metered hydraulic circuit to the closed-loop meterless hydraulic circuit.
摘要:
A hydraulic circuit for lifting and lowering a load is disclosed. The hydraulic circuit may include a hydraulic pump, a fluid reservoir, a load-sense valve, and a hydraulic actuator having a first chamber and a second chamber. The hydraulic circuit may also include a first control valve assembly having first and second lowering positions, the valve being disposed between the hydraulic pump and the hydraulic actuator. A second control valve assembly may also be provided that is disposed between the first control valve assembly and the first chamber of the hydraulic actuator. In one embodiment, the second control valve assembly has a first position and a second position. In one embodiment, the load can be selectively lowered by the hydraulic circuit without use of the hydraulic pump when the first control valve assembly is in the first lowering position and the second control valve assembly is in the second position.
摘要:
The disclosure relates to a method for actuating a hydraulic valve arrangement, having a hydraulic continuously adjustable valve and having a hydraulic switching valve for providing a variable opening cross section, wherein an opening cross section threshold value is predefined, wherein, above the opening cross section threshold value, the switching valve is placed into a defined switching position and only the continuously adjustable valve is actuated, and wherein, below the opening cross section threshold value, the continuously adjustable valve is placed into a defined switching position and only the switching valve is actuated.
摘要:
An independent flow rate controlling hydraulic system for pressure control of an excavator, in which a hydraulic system of the excavator can be variably controlled via independent flow rate control. The hydraulic system includes a plurality of actuators which actuate a working apparatus, a pressure control-type hydraulic pump which feeds working fluid to the actuator, first and second electronic proportional control valves which are disposed at a piston-side inlet flow path and a load-side inlet flow path connected from the hydraulic pump to the actuators, third and fourth electronic proportional control valves which are disposed at a piston-side outlet flow path and a load-side outlet flow path connected from the actuators to a hydraulic tank, and a control unit which variably controls areas of the flow paths by controlling the first, second, third and fourth electronic proportional control valves depending on an amount by which a control stick is manipulated.
摘要:
A hydraulic system includes a variable displacement first pump, a first linear actuator fluidly connected to the first pump via a first closed-loop circuit, a variable displacement second pump, and second and third linear actuators fluidly connected to the second pump in parallel via a second closed-loop circuit. The system also includes a variable displacement third pump, a fourth linear actuator fluidly connected to the third pump via a third closed-loop circuit, a variable displacement fourth pump, and a first rotary actuator fluidly connected to the fourth pump via a fourth closed-loop circuit. The system further includes a second rotary actuator fluidly connected to the second pump in parallel with the second and third linear actuators. The system also includes a third rotary actuator fluidly connected to the third pump in parallel with the fourth linear actuator.
摘要:
A hydraulic system for a machine is disclosed. The hydraulic system may have a tank configured to hold a supply of fluid, a pump configured to draw fluid from the tank and pressurize the fluid, a first cylinder operatively connected between a first side of a work tool and an undercarriage of the machine, and a second cylinder operatively connected between a second side of the work tool and the undercarriage of the machine. The hydraulic system may also have a first electro-hydraulic valve associated with the first cylinder and configured to selectively regulate a flow of pressurized fluid to the first cylinder independently of the second cylinder, and a second electro-hydraulic valve associated with the second cylinder and configured to selectively regulate a flow of pressurized fluid to the second cylinder independently of the first cylinder.
摘要:
A hydraulic system control unit, a hydraulic system and a working machine for controlling a hydraulic system adapted to perform at least one hydraulic work function in a working machine are provided. The hydraulic system performs the hydraulic control function in accordance with an operation signal determined by a hydraulic system control unit. In a first step the control unit receives an operator control input associated to the work function. In a second step the control unit receives a load input indicative of a load associated to the work function. Moreover, in a third step the control unit determines the operation signal in response to the operator control input and the load input.