A priority valve is disclosed for controlling fluid flow between a power source and a priority function and secondary function operated by the power source. The priority valve includes a housing having first and second bores formed therein. An inlet passage connects the power source to the first bore while first and second outlet passages connect the first bore to the primary and secondary functions respectively. A valve spool is positioned in the first bore and is movable between a first position permitting fluid flow from the inlet passage to the first outlet passage while blocking fluid flow to the second outlet passage and a second position permitting fluid flow from the inlet passage to the second outlet passage while blocking fluid flow to the first outlet passage. A pin is movably positioned in the second bore and has an enlarged end which extends into the first bore. a load signal passage connects the priority function to the second end of the first bore. When full fluid flow is demanded by the priority function the valve spool moves toward its first position. When the priority valve demands less than full flow, the spool valve moves toward its second position. If the priority function demands pressure approaching a maximum pressure value which can be delivered by the power source the enlarged end of the pin contacts the valve spool and forces it toward its second position.
A fluid pump has a housing (4), a main output port (10), an auxiliary output port (14) and a priority pressure regulating valve contained with the housing (4). The priority pressure regulating valve has a spool (20) to direct fluid to one or both of the of the output ports (10,14), a force means (34,36) associated with the spool to bias the spool (20) to a position where it causes fluid to flow to the main output port (10) exclusively, and a pressure release means (40) which enables the spool (20) to move to a position where it permits fluid to flow to the auxiliary output port (14) when the pressure at the main output port (10) is at or greater than a predetermined pressure.
A hydraulic pressure-control device, specially for powershift transmissions of motor vehicles, comprises a fluid pump (1) and a main valve for regulating the pressure in at least one high-pressure consumer device (6), which is attached to a pressure pipe (3) between the fluid pump (1) and the main pressure valve. The main pressure valve is designed as pressure-relief valve. In the main pressure valve is integrated the operation of a second pressure-relief valve. Two different pressure limits can be adjusted in the pressure pipe (3) by a valve piston (21) through two compression springs (17, 18) connected in parallel of which one compression spring (18) is bound.
A fuel delivery system for providing a desired fuel flow to an engine includes a pump means for providing fuel to a metering valve which in turn regulates the flow of fuel to provide a desired fuel flow to the engine by varying the area of the metering window. The pressure differential across the metering valve is maintained at a desired set point in order to precisely control desired fuel flow by varying the area of the metering window. The pressure differential is sensed by a pressure regulating motive flow control valve (PRMFV). The PRMFV is positioned in response to the pressure differential to bypass fuel away from the metering valve to control the differential pressure to the desired set point. The PRMFV first bypasses fuel to an ejector pump and as the amount of excess flow to the metering valve increases the PRMFV bypasses fuel back to the inlet of the pump means.
A fluid pressure driving system for a vehicle includes a reservoir tank in which an amount of fluid is stored, a variable capacity oil pump sucking the fluid from the reservoir tank and discharging the resultant fluid, a control device for adjusting a quantity of the fluid discharged from the variable oil pump, and a distributor valve having an inlet port for receiving the fluid from the variable capacity oil pump. The distributor valve discharges a fixed amount of the fluid and the remaining amount of the fluid from a first outlet port thereof and a second outlet port thereof, respectively. A first passage connects the first outlet port of the distributor valve and the reservoir tank. A second passage connects the second outlet port of the distributor valve and the reservoir tank. A power steering device is associated with a steering wheel and disposed in the first passage. A hydraulic motor is disposed in the second passage, and a cooling fan is mounted rotatably on the hydraulic motor.
A combination pressurizing valve (27) and fuel flow divider for a gas turbine is operable in three different fuel distribution modes utilizing three windows which are successively opened to control the flow distribution to the engine atomizing or start-up nozzles (23) and engine air blast or running nozzles (25) respectively by way of two fixed orifices (51, 55) in a way that satisfies the start-up flow distribution favoring the atomizing nozzles (23) as well as the need for balanced flow distribution between the different types of engine nozzles after a successful start. The first window position corresponds to an engine ignition mode and includes a range of intermediate valve spool (33, 133) positions where one outlet port (57) is open and the other outlet port (67) receives a restricted flow of fuel. The second window position includes a range of valve spool (33, 133) positions where the one outlet port (57) is open and the other outlet port (67) is open to receive a flow of fuel greater than the restricted flow. The third window position corresponds to a full power engine condition and includes a range of valve spool (33, 133) positions including the another extreme position where the one outlet port (57) is open and the other outlet port (67) is open to receive a still further increased flow of fuel.
