Abstract:
A control device for variable hydraulic machines, and specifically for variable axial piston machines equipped with a servo system that is connected to a swash plate so that the discharge/displacement volume is infinitely variable. The hydraulic machine is equipped with a sensor that detects the piston displacement and is connected with an electronical control unit that controls the swash angle position of the swash plate and is pressure controlling the servo system by an electrohydraulic converter. A method for the infinite controlling of the volume flow of hydraulic machines, by which the servo system is connected to the swash plate of the hydraulic machine, and by which a conduction of a signal from a sensor to the control unit, a pressure controlling of the servo system by an electrohydraulic converter as well as the controlling of the swash angle position of the swash plate by the electronical control unit is realized.
Abstract:
A torque limiter control sets the limit of power which may be absorbed by a pump. A feedback system adjusts the displacement of the pump in responses to changes in the pressure of working fluid at the pump outlet to maintain a set power.
Abstract:
A method and apparatus for controlling a variable displacement hydraulic pump having a swashplate pivotally attached to the pump. The method and apparatus includes determining a desired swashplate angle as a function of a power limit of the pump, determining an actual swashplate angle, determining a value of discharge pressure of the pump, moving a servo valve spool to a desired position as a function of the desired swashplate angle, the actual swashplate angle and the discharge pressure, and responsively moving the swashplate to the desired swashplate angle position.
Abstract:
A variable displacement hydraulic piston unit with electrically operated variable displacement control and timing control is disclosed, the displacement control utilizing an electric motor such as a stepper motor and cam arrangement operable for changing the tilt angle of a swash plate of the unit, and the timing control including an electric motor, such as a stepper motor operable for rotating the swash plate relative to the pistons of the unit for effecting timing changes, the unit being operable as a pump, motor, or the like.
Abstract:
An electro hydraulically adjustable pump has an adjustment member which is adjustable by at least one adjustment piston, a control valve which acts upon the at least one adjusting piston, a servo amplifier which triggers the control valve and which is supplied with an actual value of a pump adjustment and an actual value of a control valve adjustment, and an element which produces an additional pulse-shape adjusting signal as a function of an angle of rotation of the pump so as to control the control valve through the servo amplifier by the additional pulse-shaped adjustment signal.
Abstract:
A lawnmower including a frame, an engine having an electrical system and attached to the frame, the engine being started by a starter mechanism. A mower deck assembly having a rotating blade is connected to the frame with the blade being selectively engaged with the engine. A reversible transmission is driven by the engine and includes a shift mechanism having a forward, a neutral, and a reverse position, and at least one sensor for sensing the position of the shift mechanism. The sensor is capable of at least one of directing a signal to the mower deck assembly for operation and non-operation of the mower deck assembly and directing a signal to the starter circuit for prevention of start-up when the shift mechanism is not in the neutral position.
Abstract:
A method and apparatus for controlling a variable displacement hydraulic pump having a swashplate pivotally attached to the pump. The method and apparatus includes determining a desired swashplate angle as a function of a power limit of the pump, determining an actual swashplate angle, determining a value of discharge pressure of the pump, moving a servo valve spool to a desired position as a function of the desired swashplate angle, the actual swashplate angle and the discharge pressure, and responsively moving the swashplate to the desired swashplate angle position.
Abstract:
A total power regulation device for a plurality of variable displacement pumps (1, 2), each having a regulation valve (18) which regulates its displacement volume, which is acted upon--against a counter-pressure--by a control pressure corresponding to the working pressure of the variable displacement pump. When the control pressure exceeds the counter-pressure, the regulation valve regulates the variable displacement pump along a characteristic line (KL) of constant torque. To adjust the desired values of the individual drive torques simply, and to prevent torques from exceeding a desired value, an electronic control unit (16)--connected to measuring detectors (25) for detecting the displacement volumes of the variable displacement pumps--stores the desired value totals of the counter-pressures and the torque characteristic lines (KL) of the variable displacement pumps, and has a desired value setting device (27) for dividing the desired value total. The electronic control unit sets the torque characteristic lines (KL.sub.1, KL.sub.2) and sends control signals to the associated control elements (24) for generating counter-pressures which correspond to the predetermined counter-pressure desired values. The electronic control unit, upon response of each regulation valve, determines the working pressure (p)--along the torque characteristic line (KL.sub.1, KL.sub.2)--corresponding to the displacement volume (V), and processes the working pressure to a control signal for the control element for generating a counter-pressure.
Abstract:
An apparatus for regulating the speed of internal combustion engine of a hydrostatic system. A fuel control means acts to control the quantity of fuel delivered to the engine responsive to the immediate hydraulic flow demanded by operation of the hydrostatic system. The speed of the engine is set to one of a plurality of discrete levels in response to the required flow being within one of a corresponding plurality of preselected ranges.
Abstract:
A thick matter pump comprising a drive motor (50), a (reversible) hydraulic pump (6), and two hydraulic cylinders (5, 5′) coupled to conveyor cylinders (7, 7′) for conveying the thick matter. A regulator regulates the rotational speed N of the drive motor (50), and a regulating clement (18, 20) regulates the displacement volume V of the hydraulic pump (6). A control module (54) regulates the rotational speed N of the motor and the displacement volume V. For improved operational ease and reduction of fuel requirements, noise and waste gas emission, the control module (54) comprises a final control element (56) for regulating the conveyance capacity of the conveyor cylinders (7, 7′), and an electronic control unit (108) which reacts to the position of the final control element (56) and allocates a nominal value to the rotational speed regulator and to the displacement volume regulator (20), in a software-assisted manner.