Abstract:
A valve for controlling pressure in a system is provided. The valve includes a housing, a servo spool and a piston positioned within the housing with the piston and the servo spool being movable relative to each other. The piston defines a first orifice configured to communicate with a supply of pressurized fluid and a second orifice configured to communicate with a portion of the system exterior to the valve. A first chamber is arranged such that force due to fluid pressure in the first chamber is configured to move the piston in a first direction. The first chamber includes a third orifice configured to communicate with a controlled pressure in the system. A second chamber is at least partially defined by the housing and the piston and includes a fourth orifice configured to communicate with a low pressure fluid source. A biasing element is arranged in the second chamber. First and second fluid passages are provided in the servo spool and are configured such that in at least one relative position of the piston and the servo spool the first passage provides communication between the first orifice and the second orifice and in at least one other relative position the second passage provides communication between the second orifice and the fourth orifice.
Abstract:
A method is disclosed that includes allowing both frequency and amplitude of a periodic waveform to be adjusted. The method also includes creating the periodic waveform having the frequency and the amplitude. The periodic waveform is coupled to at least one control signal. The at least one control signal is provided to an output suitable for coupling to an actuator of an electronically controlled device. An apparatus and computer program product are disclosed.
Abstract:
Disclosed is an exemplary valve having a first valve member that may include at least one orifice, and which is moveable between a first position and a second position, and a second valve member that includes at least one orifice, and which is moveable relative to the first valve member between a first position, in which the at least one orifice of the second valve member is fluidly disconnected from the at least one orifice of the first valve member, and a second position, in which the at least one orifice of the second valve member is fluidly connected to the at least one orifice of the first valve member. The exemplary valve may also include first and second actuators for moving the first and second valve members between their respective first and second positions.
Abstract:
An actuation system (200) is provided. The actuation system (200) includes a fluid operated actuator (211) and a control valve (230). The control valve (230) is movable between a first position and a second position and is adapted to open a fluid flow path from a pressurized fluid supply (240) to the actuator (211) when the control valve (230) is in the first position. A diverting fluid conduit (246) is provided that is adapted to divert a portion of the pressurized fluid supplied to the actuator (211) when the control valve (230) is in the first position. The pressurized fluid diverted through fluid conduit (246) biases the control valve (230) towards a second position.
Abstract:
A stepper motor driven actuator that eliminates the need for a position sensor is provided. The stepper motor rotates a cam in a control piston valve. In a single nozzle embodiment, pressure balance is maintained by a spring preload on one end of the piston in one embodiment, and by hydraulic pressure acting on a double diameter end portion of the piston in another embodiment. As the cam is rotated, the change in the gap between the nozzle and the cam changes the pressures on the control piston ends, which forces the piston in the direction that will re-equalize the pressure based on the cam-nozzle gap. As a result, the head or rod of the actuator piston receives high pressure flow, thereby moving the actuator. Movement of the actuator rod provides mechanical feedback to the cam, causing the cam to move back to its mechanical null position.
Abstract:
A hydraulic control valve with a monolithic body having four sides located between a top and a bottom, and all pilot ports on a body front side, valve work ports on the top side, three bores running within the body from the front side to a rear side, a spool in each bore, and a single three section spool port lock that locks two or three ports at the same time, the pilot ports presented machined female quick-connect connections, with spring wet cavities being provided for mechanically operated control spools.
Abstract:
A method of operating a control valve assembly for a hydraulic system includes detecting the current operation of a first position sensor and a second position sensor to determine if at least one of the first position sensor and the second position sensor is inoperable. A pressure of the fluid at a first work port and a second work port is measured, and one of a first valve and a second valve is actuated when one of the first position sensor and the second position sensor is determined to be inoperable. The first valve is actuated based upon the fluid pressure measured at the second work port to adjust the flow of the fluid through the first work port. The second valve is actuated based upon the fluid pressure measured at the first work port to adjust the flow of the fluid through the second work port.
Abstract:
A low energy stepper motor driven fuel metering valve (FMV) that eliminates the need for a position sensor is provided. The stepper motor rotates a cam that replaces the flapper valve used in conventional systems. The cam rotation increases the gap between the cam and nozzle on one side of the cam. The gap difference affects the pressures on the spool piston ends, which forces the piston in the direction that will return the cam-nozzle gap to a distance that results in a pressure balance to return. As a result, the relatively low energy stepper motor controls the relatively high energy hydromechanical system via the cam-nozzle-orifice system. The cam is precision machined and assures stroke/degree gain accuracy. The hydraulic system assures the piston tracks the cam essentially perfectly except for the effects of piston stiction forces.
Abstract:
A controller for controlling a valve is disclosed including a manifold assembly, a valve position indicator and a trigger assembly. An operating media distribution system is disposed in the manifold assembly and an electronic control unit is disposed in the controller. The electronic control unit operates at least one electromagnetic valve to control operating media flow via the operating media distribution system to activate an actuator which opens or closes the valve. The trigger assembly includes a cylinder adapted to receive an actuator shaft and provide a self setting mechanism corresponding to the stroke length of the actuator shaft.
Abstract:
A method for actuating a hydraulic servo system with a proportional valve that converts an electrical control signal into a hydraulic pilot pressure with which the hydraulic servo system is actuated. An additional impulse is fed to the proportional valve at the beginning of a desired change of the electrical control signal.