Starting system for a turbine engine

Claim 2

In a turbine engine having a compressor with a bleed valve device and a variable geometry apparatus responsive to an operational control member for regulating the flow rate of fuel supplied through a conduit to the turbine engine as a function of atmospheric pressure and the temperature of the air supplied to the compressor in response to an operator input, the improvement wherein starting control means schedules fuel flow to said turbine engine as a function of time, said starting control including: first compensating means for modifying said scheduled fuel flow in response to changes in temperature; and second compensating means for modifying said function of time in response to changes in altitude.

Claim 3

In a turbine engine having a compressor with a bleed valve device and a variable geometry apparatus responsive to an operational control member for regulating the flow rate of fuel supplied through a conduit to the turbine engine as a function of atmospheric pressure and the temperature of the air supplied to the compressor in response to an operator input, the improvement wherein starting control means schedules fuel flow to said turbine engine as a function of time, said starting control means including: compensating means for modifying said function of time in response to changes in altitude.

Claim 4

In a turbine engine having a compressor with a bleed valve device and a variable geometry apparatus responsive to an operational control member for regulating the flow rate of fuel supplied through a conduit to the turbine engine as a function of atmospheric pressure and the temperature of the air supplied to the compressor in response to an operator input, the improvement wherein starting control means schedules fuel flow to said turbine engine as a function of time, said starting control means including: compensating means for modifying said function of time in response to changes in altitude.

Claim 5

In the turbine engine, as recited in claim 1, wherein said operational control member includes: a power lever through which an operator transmits a request for power from the turbine engine, said power lever being moved from a cut-off position to an idle position to bring the turbine engine into operation.

Claim 6

In the turbine engine, as recited in claim 3, wherein starting control means includes: a pilot valve connected to said power lever and to a source of operational fluid, said pilot valve responding to movement of said power level to said cut-off position to allow said operational fluid to develop a reset start signal.

Claim 7

In the turbine engine, as recited in claim 4, further including: a cut-off valve connected to said conduit through which fuel is supplied to the turbine engine, said cut-off valve being responsive to said reset start signal to interrupt the flow of fuel to said turbine engine.

Claim 8

In the turbine engine, as recited in claim 5, wherein said operational control member further includes: a first shaft; a scheduling cam located on said first shaft and connected to said power lever, said scheduling cam having a surface that corresponds to a fuel to air ratio through which fuel is supplied to the turbine engine to obtain the requested power.

Claim 9

In the turbine engine, as recited in claim 6, wherein said first compensating means includes: a probe for measuring the temperature of the air supplied to the compressor to establish a temperature signal; and means responsive to said temperature signal to move said scheduling cam on said first shaft to modify the fuel to air ratio requested by the power lever position.

Claim 10

In the turbine engine, as recited in claim 7, wherein said starting control means includes: a first housing having a cavity therein with first and second ports connected to the operational fluid; a timer piston located in said cavity to define first and second chambers between said first and second ports; a stem extending through said first housing and fixed to said timer piston to reduce the effective area of the timer piston in said first chamber as compared to said second chamber, said operational fluid acting on the areas of the timer piston in said first and second chambers to develop a force to move said timer piston in said cavity; and linkage means connected to said scheduling cam, said second compensating means and said stem for moving a metering valve to an optimum fuel flow position to start the turbine engine when the power lever is moved from the cut-off position to the idle position.

Claim 11

In the turbine engine, as recited in claim 8, wherein said starting control means further includes: a fuel management valve connected to the operational fluid of said second port of said first housing and said pilot valve, said fuel management valve being responsive to said reset start signal to interrupt the communication of the operational fluid to said second chamber and allow the operational fluid in said first chamber to move said timer piston from an inactive position to a reset position, said second compensating means responding to the movement of said timer piston to provide said linkage with rotational movement to move said metering valve into a position corresponding to the fuel flow required to start said turbine engine.

Claim 12

In the turbine engine, as recited in claim 8, wherein said linkage means includes: a second shaft; a first cam located on said second shaft, said first cam having a surface thereon corresponding to altitude; said first cam being connected to said second compensating means; and a first lever secured to said first housing for connecting said stem of the timer piston to said first cam, said first lever moving said first cam in response to movement of said timer piston.

Claim 13

In the turbine engine, as recited in claim 10, wherein said second compensating means includes: a second housing having a bore therein; a gear fixed to said second shaft and connected to said first cam; a power piston located in said bore to establish a power chamber and an operational chamber, said power chamber being connected to a relief port and said operational chamber being connected to said operational fluid, said power piston being connected to said gear; a passage in said second housing for connecting said operational chamber to said power chamber; an orifice member in said passage for restricting the flow of the operational fluid into said power chamber; and first follower means connected to said first cam for regulating the flow of the operational fluid from said relief port as a function of the position of said first cam on said second shaft.

Claim 14

In the turbine engine, as recited in claim 11, wherein said second compensating means further includes: altitude responsive means connected to said first follower means for modifying the flow of the operational fluid through said relief port as a function of atmospheric pressure, said movement of said timer piston moving said first cam which moves said first follower means and changes the flow of the operational fluid from said power chamber through the relief port to permit a pressure differential to act on and move the power piston to provide said gear with a rotational movement, said rotational movement being transmitted to said metering valve as time modified altitude compensation.

Claim 15

In the turbine engine, as recited in claim 12, wherein said altitude responsive means includes: an aneroid member; a first beam having a first end and a second end; a pin connected to said beam for establishing a fulcrum to locate said first end adjacent said relief port, said first beam being connected to said first follower means; and an arm extending from said first beam and connected to said aneroid member, said aneroid member acting on said arm in response to changes in pressure in the air supplied to the compressor to pivot said beam around said fulcrum and change the position of said first end with respect to said relief port to modify the flow of operational fluid from the power chamber.

Claim 16

In the turbine engine, as recited in claim 13, wherein said second compensating means further includes: a second beam having a pivotally fixed end; a roller located between said first and second beams and connected to said first follower means; and a spring acting on said second beam to provide a resilient force on said roller to oppose the movement of said first beam by said aneroid member.

Claim 17

In the turbine engine, as recited in claim 14, wherein said first follower means moves said roller between said first and second beams to move said first end with respect to said relief port and thereby very the flow of the operational fluid therefrom, said operational fluid in the power chamber thereafter acting on said power piston to provide said gear with a torque to rotate said first cam and reposition said roller at a position wherein the force from said aneroid member is balanced with the force from said spring.

Claim 18

In the turbine engine, as recited in claim 15, wherein said starting control means further includes: a second cam fixed to said first cam; and a second follower means connected to said second cam for providing the bleed valve device and variable geometry apparatus with an operational signal for starting of the turbine engine.

Claim 19

In the turbine engine, as recited in claim 16, wherein said starting control means further includes: a third housing having a bore therein with an entrance port connected to said operational fluid, an exit port connected to the variable geometry apparatus, a first and second exhaust port for connecting said bleed valve device and variable geometry apparatus to a reservoir; and a spool valve located in said bore and connected to said second follower means, said movement of said second follower initially interrupting the flow of the operational fluid between said entrance port and said exit port for distribution to said variable geometry apparatus and the first exhaust port and the bleed valve device and thereafter allowing operational fluid to flow from the variable geometry apparatus to the reservoir through said second exhaust port.

Claim 20

In the turbine engine, as recited in claim 17, further including: a third cam located on said second shaft and connected to said second cam, said rotational movement of said second shaft being communicated to said third cam; a scheduling follower connected to said scheduling cam for providing said third cam with a fuel air ratio request modified by temperature; and third follower means connected to said third cam and a second lever for providing said metering valve with an operational input modified by pressure and temperature.

Claim 21

In the turbine engine, as recited in claim 18, further including: a variable geometry valve having a bore therein with first and second ports connected to said operational fluid, a third port connected to the exit port of the third housing and fourth and fifth ports connected to the variable geometry apparatus; and a second spool valve located in bore and having a series of lands thereon to control communication of the operational fluid from said second port to one of said fourth and fifth ports and a power land for separating said first port from said third port, said power land responding to the operational fluid communicated to said bore through said first port when said third port is communicated to the reservoir to move said series of lands and allow operational fluid to flow to and position the variable geometry apparatus at a position to start the turbine engine.

Claim 22

In the turbine engine, as recited in claim 19, further including: feedback means connected to said variable geometry apparatus for providing an indicator signal corresponding to the position of said variable geometry apparatus; a third shaft connected to said feedback means; a variable geometry cam splined to said third shaft; and a variable geometry follower means connected to said variable geometry cam for providing said second spool valve with an input corresponding to said indicator signal.

Claim 23

In the turbine engine, as recited in claim 20, further including: scheduling follower means connected to said scheduling cam to provide said variable geometry cam with a modification corresponding to the temperature measured by said probe.

Claim 24

In the turbine engine, as recited in claim 21, wherein said second spool valve includes: a passage for connecting said third port to said exhaust reservoir; and a cylindrical member connected to said variable geometry follower means and located in said passage to restrict the flow of operational fluid through said third port to the exhaust reservoir and match the resultant force generated across said cylindrical member with the input from the variable geometry follower means.

Claim 25

In the turbine engine, as recited in claim 8, wherein said pilot valve further includes: a bypass conduit for connecting the fuel flow from said metering valve with the exhaust reservoir when said power lever is in said cut-off position.

Claim 26

In the turbine engine, as recited in claim 23, wherein said pilot valve terminates the flow of operational fluid to said fuel management valve when said power lever is moved to said idle position, said fuel management valve thereafter moving to allow said operational fluid to flow to said second chamber and move said timer piston toward said inactive position in a time period equal to the optimum starting condition of the turbine engine for the existing atmospheric pressure and temperature.

Claim 27

In the turbine engine, as recited in claim 9, wherein: said fuel management valve in response to said reset start signal interrupts the communication of said operational fluid to any accessories associated with said turbine.

Claim 28

In the turbine engine, as recited in claim 25, wherein: said fuel management valve sustains said interruption of the operational fluid communication to said accessories until the turbine engine substantially reaches idle speed.

Claim 29

In the turbine engine, as recited in claim 26, wherein said fuel management valve further includes: a second housing having a bore therein with first and second ports connected to said operational fluid, a third port connected to said second port of said second chamber retaining said timer piston, a fourth port connected to said pilot valve, a fifth port connected to the accessories, and a sixth port connected to an exhaust reservoir; and spool valve means located in said bore having a first pressure surface connected to first port and a second pressure surface connected to said fourth port, said reset start signal acting on said second pressure surface to initially interrupt the communication of the operational fluid to the accessories through said fifth port and to the timer piston through the third port and thereafter provide a flow path between said third and fifth ports to the sixth port for exhausting any operational fluid from the accessories and the timer piston.

Claim 30

In the turbine engine, as recited in claim 27, wherein said spool valve means includes: a first cylindrical member located in said bore having a first end and a second end, said first end forming said first pressure surface, said first cylindrical member having a blind bore that extends from said second end toward said first end, said first cylindrical member having a radial passage that connects the blind axial bore with the bore; a second cylindrical member located in said bore having a first end that extends into said blind axial bore of the first cylindrical member and a second end, said second end forming said second pressure surface; and a spring located between first and second cylindrical members, said reset start signal acting on said second cylindrical member and interrupt operational fluid communication from said second port to said third port of said second housing and thereafter establish a flow path between said third port and said sixth port for exhausting fluid from said second chamber to allow the timer piston to move to said reset position, said spring on movement of said second cylindrical member by the reset start signal moving said first cylindrical member to interrupt communication of the operational fluid between said first port and said fifth port and thereafter allow fluid communication between said fifth port and said sixth port to exhaust fluid from the accessories, said blind bore initially being connected to said sixth port through said radial passage and on movement of said first cylindrical member fluid communication is interrupted and thereafter connected to said operational fluid, said operational fluid in said blind axial bore acting on said first end of said second cylindrical member and the bottom of the blind axial bore to retain said first cylindrical member in a fixed position on initiation of said reset start signal.

Claim 31

In the turbine engine, as recited in claim 28, wherein: said operational fluid communicated to said blind axial bore terminates when the turbine engine reaches idle operation and thereafter allow said operational fluid from said first port to act on said first pressure surface and reposition said first cylindrical member to permit operational fluid communication through said fifth port to the accessories and the blind axial bore to be exhausted through the radial passage and sixth port.

Claim 32

In the turbine engine, as recited in claim 2, wherein said operational control member includes: a power lever through which an operator transmits a request for power from the turbine engine, said power lever being moved from a cut-off position to an idle position to bring the turbine engine into operation.

Claim 33

In the turbine engine, as recited in claim 2, wherein starting control means includes: a pilot valve connected to said power lever and to a source of operational fluid, said pilot valve responding to movement of said power lever to said cut-off position to allow said operational fluid to develop a reset start signal.

Claim 34

In the turbine engine, as recited in claim 2, wherein said operational control member further includes: a first shaft; a scheduling cam located on said first shaft and connected to said power lever, said scheduling cam having a surface that corresponds to a fuel to air ratio through which fuel is supplied to the turbine engine to obtain the requested power.

Claim 35

In the turbine engine, as recited in claim 32, wherein said starting control means includes: a first housing having a cavity therein with first and second ports connected to the operational fluid; a timer piston located in said cavity to define first and second chambers between said first and second ports; a stem extending through said first housing and fixed to said timer piston to reduce the effective area of the timer piston in said first chamber as compared to said second chamber, said operational fluid acting on the areas of the timer piston in said first and second chambers to develop a force to move said timer piston in said cavity; and linkage means connected to said scheduling cam, said compensating means and said stem for moving a metering valve to an optimum fuel flow position to start the turbine engine when the power lever is moved from the cut-off position to the idle position.

Claim 36

In the turbine engine, as recited in claim 33, wherein said starting control means further includes: a fuel management valve connected to the operational fluid of said second port of said first housing and said pilot valve, said fuel management valve being responsive to said reset start signal to interrupt the communication of the operational fluid to said second chamber and allow the operational fluid in said first chamber to move said timer piston from an inactive position to a reset position, said compensating means responding to the movement of said timer piston to provide said linkage with rotational movement to move said metering valve into a position corresponding to the fuel flow required to start said turbine engine.

Claim 37

In the turbine engine, as recited in claim 33, wherein said linkage means includes: a second shaft; a first cam located on said second shaft, said first cam having a surface thereon corresponding to altitude, said first cam being connected to said compensating means; and a first lever secured to said first housing for connecting said stem of the timer piston to said first cam, said first lever moving said first cam in response to movement of said timer piston.

Claim 38

In the turbine engine, as recited in claim 35, wherein said second compensating means includes: a second housing having a bore therein; a power piston located in said bore to define a power chamber and an operational chamber in said second housing, said operational chamber being connected to said operational fluid and said power chamber, and power chamber being connected to a relief chamber, said power piston being connected to said second shaft; a restriction member for regulating the flow of operational fluid from the operational chamber to the power chamber; and follower means connected to said first cam for regulating the flow of the operational fluid from said relief port as a function of the position of said first cam on said second shaft.

Claim 39

In the turbine engine, as recited in claim 36, wherein said compensating means further includes: altitude responsive means connected to said linkage means for modifying the flow of the operational fluid from said power chamber to said relief chamber as a function of atmospheric pressure to permit a pressure differential to develop and act on said power piston for moving said second shaft to a position whereby the operational movement transmitted to said metering valve is time modified altitude compensated.

Claim 40

In the turbine engine, as recited in claim 32, wherein said starting control means includes: temperature compensating means for modifying said scheduled fuel flow in response to changes in temperature.

Claim 41

In the turbine engine, as recited in claim 38, wherein said temperature compensating means includes: a probe for measuring the temperature of the air supplied to the compressor to establish a temperature signal; and means responsive to said temperature signal to move said scheduling cam on said first shaft to modify the fuel to air ratio requested by the power lever position.

Claim 42

In the turbine engine, as recited in claim 31, wherein said pilot valve further includes: a bypass conduit for connecting the fuel flow from said metering valve with the exhaust reservoir when said power lever is in said cut-off position.

Claim 43

In the turbine engine, as recited in claim 34, wherein said pilot valve terminates the flow of operational fluid to said fuel management valve when said power lever is moved to said idle position, said fuel management valve thereafter moving to allow said operational fluid to flow to said second chamber and move said timer piston toward said inactive position in a time period equal to the optimum starting condition of the turbine engine for the existing atmospheric pressure and temperature.

Claim 44

In the turbine engine, as recited in claim 34, wherein: said fuel management valve in response to said reset start signal interrupts the communication of said operational fluid to any accessories associated with said turbine.

Claim 45

In the turbine engine, as recited in claim 42, wherein: said fuel management valve sustains said interruption of the operational fluid communication to said accessories until the turbine engine substantially reaches idle speed.