초록 ▼

An unbalance compensated bypass valve (23) for a gas turbine engine fuel supply system is responsive to the fuel pressure differential across a fuel metering valve (15) to open and close a bypass orifice (37, 39, 41). The bypass valve (23) selectively supplies high fuel pressure to providing a count

An unbalance compensated bypass valve (23) for a gas turbine engine fuel supply system is responsive to the fuel pressure differential across a fuel metering valve (15) to open and close a bypass orifice (37, 39, 41). The bypass valve (23) selectively supplies high fuel pressure to providing a counterbalancing force against an annular area (47) of the bypass valve piston 34 to compensate for increased restorative forces of a helical reference spring (57) as that spring is compressed as well as to compensate for other unbalance conditions within the valve (23). The piston (34) includes additional sidewall openings (69, 70, 71) which function during a "shut-off" condition to divert all fuel flow from an inlet of the metering valve (15) back to a fuel pump (13) inlet. The piston (34) also includes further sidewall openings (73, 75) which provide a controlled fuel leakage from a bypass valve inlet line (25) to the bypass valve pressure sensing inlet (29).

대표청구항 ▼

[ What is claimed is:] [1.] A bypass valve for diverting selectively fluid from a high pressure source to a low pressure return for maintaining substantially constant a pressure differential between the high pressure of the source and a monitored intermediate pressure comprising:a valve housing incl

[ What is claimed is:] [1.] A bypass valve for diverting selectively fluid from a high pressure source to a low pressure return for maintaining substantially constant a pressure differential between the high pressure of the source and a monitored intermediate pressure comprising:a valve housing including an inlet adapted to be coupled to the high pressure source, an outlet adapted to be coupled to the low pressure return, and a sensing inlet adapted to receive the intermediate pressure;a movable piston having a pair of opposed faces and disposed within the valve housing for reciprocable motion along an axis, the piston having one extreme position allowing maximum flow of fluid from the high pressure source inlet to the outlet, another minimum flow extreme position substantially blocking any fluid flow from the high pressure source inlet to the outlet, and a range of intermediate positions allowing a controlled bypassing of fluid from the source to the return for maintaining the pressure differential substantially constant, the piston having a hollow interior region communicating with the high pressure source inlet and including a plurality of sidewall openings, the housing including an inner annular region communicating with the outlet, and the sidewall openings and annular region cooperating to define a variable size bypass orifice;means within the housing for supplying high pressure fluid from the high pressure source inlet to one piston face to urge the piston toward the one extreme position;means within the housing for supplying intermediate pressure fluid from the sensing inlet to another piston face to urge the piston toward the minimum flow extreme position;spring means within the housing engaging and applying a variable force to the piston to urge the piston toward the minimum flow extreme position; anda counterbalancing force region associated with the piston and receiving a variable fluid pressure for supplying a variable counterbalancing force to the piston to urge the piston toward the one extreme position, the counterbalancing force varying to compensate for the variable force applied to the piston by the spring means as the piston moves.