Abstract:
The invention provides a method and system for regulating pressure equalization in hydraulic mechanisms. The system includes a main body, a thermal element positioned within the main body, a pin positioned adjacent to the thermal element, and an orifice spool in communication with the pin. The thermal element expands to force the pin to reposition the orifice spool, and restrict fluid flow through the main body. The method includes expanding a thermal polymer when temperature increases, contracting the thermal polymer when the temperature decreases, and metering fluid flow based on the expanding and contracting of the thermal polymer.
Abstract:
In a vehicle having a power shift transmission engageable in a plurality of forward gear ratios by engaging and disengaging first and second fluid clutches with a fluid from a fluid supply, a manifold apparatus for measuring a pressure of the fluid and simultaneously filling the first and second clutches with the fluid supply having a first clutch fill valve fluidly coupled to the first clutch to control the flow of the fluid to the first clutch; a second clutch fill valve fluidly coupled to the second clutch to control the flow of the fluid to the second clutch; a manifold fluidly coupled to the first and second clutch valves to conduct the fluid from the fluid supply to the first and second clutch valves; a first flow restrictor disposed between the manifold and the fluid supply to restrict the flow of the fluid from the fluid supply to the manifold; and a pressure transducer fluidly communicating with the manifold to generate a signal representative of the pressure of the fluid within the manifold, where the first and second clutches are not simultaneously engaged to provide any of the plurality of forward gear ratios.
Abstract:
A work vehicle configured for selectively applying power to a load and comprising a frame, a plurality of ground support devices movably secured to the frame, an engine supported by the frame, a source of hydraulic fluid at a pressure, a clutch for selectively coupling the engine to the load in response to a control signal, the clutch including a clutch actuator configured for engaging the clutch upon receipt of an actuating fluid at least a first predetermined pressure, the clutch configured to dissipate heat of engagement to a flow of a lube fluid; and a clutch control valve located intermediate the fluid source and the clutch and disposed in the path of the actuating fluid and the lube fluid. The control valve is configured to control flow of the lube fluid to the clutch to a first predetermined rate while the clutch is not engaged, to control flow of the lube fluid to the clutch to a second predetermined rate at least for a predetermined length of time prior to engagement of the clutch, and to control flow of the actuating fluid at a predetermined pressure to the clutch actuator after the flow rate of the lube fluid has been increased.
Abstract:
A simplified brake control system comprises a source of pressurized fluid, a spring-set brake with a hydraulic release mechanism and a control valve connected between the brake and the source. The control valve has a valve body and a flow control mechanism in the body and mounted for movement between a first (solenoid-energized) position and a second (solenoid-de-energized) position. A one-way check valve is built into the valve body. How the system operates depends upon two factors, namely, (a) whether the valve flow control mechanism is in its first or its second position, and (b) the relationship of the pressure of the source, i.e., the first pressure, and the second pressure in the release mechanism. When the flow control mechanism is in the first position, the release mechanism may be pressurized for brake release. And when such mechanism is in the second position, the release mechanism is vented to the reservoir through the brake port, the second passage and the drain port. A new method for controlling a brake is also disclosed.
Abstract:
The hydraulic coupler is used for connecting a valve to a tool used with a vehicle having a hydraulic pump and fluid communication with the valve through hydraulic plumbing. The hydraulic coupler comprises a coupler body having a base portion, a neck portion and a connector portion. The coupler body is two connector chambers in the connector portion which arc in fluid communication with two apertures, which when the hydraulic coupler is mounted on the valve, are in fluid communication with the valve. A connector assembly, typically of the quick-connect type, is mounted in each connector chamber and is configured to receive hydraulic plumbing to connect the valve to the tool. One embodiment provides that the coupler body is narrower than the valve on which it is mounted. Another embodiment provides before the connector portion to be offset from the neck portion thereby allowing the hydraulic couplers to be mounted immediately adjacent to each other but rotate at a 180° in relation to the other hydraulic coupler. Such arrangement forms a nested stack of hydraulic couplers mounted on the work vehicle at convenient locations on the vehicle.
Abstract:
A control apparatus for selectively operating any one of at least three fluid pressure operated devices at any given time. The control system includes first and second valves arranged in combination with each other and which are hydraulically interposed between a fluid pressure source and each of the fluid operated devices. Each valve is shiftable between first and second positions. Hydraulic logic circuitry selectively connects the first valve to the fluid operated devices and selectively connects the second valve to the first valve whereby, for any one position of the two valves, only one of the fluid operated devices is connected to the fluid pressure source while the remainder of the fluid operated devices are open to exhaust. First and second ON/OFF solenoid operated valves facilitate positioning of the first and second valves in response to electrical signals received by the ON/OFF valves.
Abstract:
The invention provides a system for regulating pressure equalization in hydraulic mechanisms to suppress oscillation in heavy equipment. The system includes a first and second hydraulic lines, a crossover valve in communication with each of the first and second hydraulic lines, a timing system in communication with the crossover valve, and a motion detector in communication with a heavy equipment component. The motion detector senses a linkage motion and operatively opens the crossover valve, which remains open as directed by the timing system.
Abstract:
Disclosed is a modulating hydraulic circuit for controlling a clutch such as the clutch on a power takeoff (PTO) shaft. The circuit includes a throttling valve having (a) an inlet port for receiving hydraulic fluid from a source, and (b) a discharge port connected to the clutch. The discharge port is also connected to an accumulator which is at an accumulator pressure. The discharge port and the clutch are at a pressure generally proportional to the accumulator pressure. As accumlator pressure rises at a controlled rate, the clutch is progressively engaged. Optionally, the circuit includes a brake control valve for "softly" disengaging a PTO shaft brake as the accumulator pressure rises. A method for controlling the clutch includes flowing hydraulic fluid through hydraulic lines to a throttling valve connected to an accumulator and to the clutch, increasing pressure in the lines and progressively engaging the clutch.
Abstract:
A valve unit for use in a load sensing system having a fluid operated cylinder. The valve unit permits positioning of an implement between the raise, lower, neutral and float positions and also provides for throttling of fluid flow to the cylinders as well as priority flow to the system. Float is obtained through a lock check valve which includes a main poppet maintained in a seated position by a spring biased pilot poppet. A pilot piston is positioned coaxially opposite the main poppet and is responsive to fluid pressure in the valve to act upon the pilot poppet and unseat the main poppet. In the float position, the fluid pressure within the valve may be stand-by pressure which acts upon the pilot piston to allow it gradual decent of the implement. The pilot pressure is communicated to the pilot piston through a centrally located passage. The location of the passage permits additional lock check valves to be easily added as needed. An adjustable priority flow control valve is included in the valve body for manual adjustment of the priority in the system and the flow rate of fluid.
Abstract:
The apparatus uses an electrical signal controlled valve, for instance, a proportional solenoid controlled valve, controlled by a controller, to control a pilot operated valve for regulating pressure of fluid in a port thereof in connection with a fluid operated system. A pressure sensor in connection with the port is used to monitor the regulated pressure. The regulated pressurized fluid in the port is also used, as required, as a component of the pilot signal. The valves are configured such that when the electrical control signal is absent or the electrically controlled valve is unresponsive thereto, the presence of pressurized fluid at a predetermined supply pressure, will automatically operate the pilot operated valve in cooperation with a biasing element thereof, for delivering pressurized fluid at a minimum or reduced regulated pressure.