Pressurized oil supply for propeller engine system
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
B64C-011/40
B64C-011/00
B64C-011/42
출원번호
US-0739951
(2003-12-19)
발명자
/ 주소
Waddleton,David
출원인 / 주소
Pratt &
Whitney Canada Corp.
대리인 / 주소
Ogily Renault LLP
인용정보
피인용 횟수 :
20인용 특허 :
16
초록
A system and method for providing pressurised oil during non-feathered in-flight shutdown conditions in a variable-pitch aircraft propeller engine. A secondary pump provides pressurised oil substantially independent of an engine main oil circuit.
대표청구항▼
What is claimed is: 1. A backup system for providing pressurised oil to a propeller control system during an in-flight shutdown of an engine, the propeller control system including an oil circuit normally fed by a propeller pump having an outlet connected to a propeller control unit and an inlet co
What is claimed is: 1. A backup system for providing pressurised oil to a propeller control system during an in-flight shutdown of an engine, the propeller control system including an oil circuit normally fed by a propeller pump having an outlet connected to a propeller control unit and an inlet connected to a supply of pressurised oil during engine operation, the backup system comprising a secondary pump selectively connectable to said oil circuit and adapted to selectively supply said oil circuit with a flow of pressurized oil during said in-flight engine shutdown, the secondary pump including an ejector pump having an ejector pump inlet and an injector pump outlet selectively connectable in fluid flow communication with said oil circuit, the oil in the oil circuit being used as a motive fluid for the ejector pump to passively draw additional oil in the oil circuit. 2. A system as defined in claim 1, wherein said ejector pump inlet and said ejector pump outlet are respectively connected to said propeller pump outlet and said propeller pump inlet to selectively communicate with said propeller pump outlet and said propeller pump inlet upon said in-flight shutdown, and wherein the propeller pump provides the motive fluid to drive the ejector pump. 3. A system as defined in claim 2, wherein said ejector pump is adapted to draw oil from a sump of a propeller reduction gear box. 4. A system as defined in claim 1, further comprising a switching unit adapted to selectively permit fluid communication between the propeller pump and the secondary pump. 5. A system as defined in claim 4, wherein said switching unit includes a valve which is responsive to a parameter indicative of an operational status of the engine, and wherein the valve is automatically switched to connect the outlet of the secondary pump to the propeller pump inlet during said in-flight engine shutdown. 6. A system as defined in claim 5, wherein said valve is responsive to fluid pressure at the inlet of the propeller pump for connecting said secondary pump to the inlet of the propeller pump when fluid pressure at the inlet of the propeller pump is below a predetermined value indicative of said n-flight engine shutdown. 7. A system for providing a secondary pressurized oil supply to an engine during in-flight shutdown conditions, the engine having a main pressurised oil circuit comprising a main pump operational at least during regular engine operation, the system comprising a secondary oil circuit selectively connectable to the main oil circuit in the event of an engine in-flight shutdown, the secondary circuit including a secondary pump adapted to pressurise oil in the secondary circuit to a predetermined pressure at least during said in-flight shutdown conditions, the predetermined pressure exceeding a nominal oil pressure in the main pressurised oil circuit during said in-flight shutdown conditions, wherein the secondary pump is selectively connectable to an inlet of said main pump to provide a pressurised oil supply at said inlet of said main pump during said in-flight shutdown conditions, and wherein said secondary pump comprises an ejector pump having an ejector pump inlet and an ejector pump outlet, said ejector pump inlet and said ejector pump outlet being respectively connected in selective fluid flow communication with an outlet and an inlet of the main pump. 8. A system as defined in claim 7, wherein said main pump is a propeller pump having an outlet connected to a propeller control system. 9. A system as defiled in claim 8, wherein said ejector pump is adapted to pump oil from a sump to feed said propeller pump inlet using surplus oil pumped by the propeller pump as a motive fluid. 10. A system as defined in clam 9, wherein said sump is located in a propeller reduction gear box, and wherein said ejector pump is located at a lower level than a scavenge return line of said sump. 11. A system as defined in claim 7, wherein said secondary circuit includes a switching unit adapted to automatically connect the secondary circuit to the main oil circuit upon the occurrence of the in-flight shutdown condition. 12. A system as defined in claim 11, wherein said switching unit includes a valve which is responsive to a parameter indicative of an operational status of the engine, and wherein the parameter is selected from a group comprising: an oil pressure, an engine fluid pressure, an engine shaft rotational speed, an engine temperature and a manually-operated switch. 13. A system as defined in claim 12, wherein said valve is responsive to the oil pressure in said main circuit to disconnect said main circuit from said inlet of said main pump and to connect said secondary circuit to said inlet of said main pump when the oil pressure in the main circuit is below a predetermined value. 14. A turboprop engine comprising a propeller having a number of variable pitch blades, a pitch control system for governing the operation of said variable pitch blades, said pitch control system employing a pressurized fluid as a means of system actuation, a propeller pump having an outlet for providing a pressurized fluid supply to said pitch control system, a main pressurized fluid source for providing a pressurized fluid supply to an inlet of said propeller pump, and a pressurized fluid back-up system for enabling operation of the pitch control system during in-flight engine shutdown conditions when said main source of pressurized fluid is unavailable, said pressurized fluid back-up system comprising a secondary source of pressurized fluid available to provide a pressurized fluid supply to said propeller pump inlet during in-flight shutdown, and a switching unit having a first state in which said main source of pressurized fluid is connected to the propeller pump inlet and said secondary source of pressurized fluid is disconnected from the propeller pump inlet, and a second state in which the secondary source of pressurized fluid is connected, to said propeller pump inlet, while said main source of pressurized fluid, is disconnected from the propeller pump inlet, said secondary source of pressurized fluid comprises a passive pump driven by surplus fluid supplied by said propeller pump. 15. A turboprop engine as defined in claim 14, wherein said turboprop engine comprises a turbine, and wherein said main SOURCE of pressurized fluid comprises a first pump, said first pump being driven by said turbine. 16. A turboprop engine as defined in claim 14, wherein said passive pump is an ejector pump connected in a loop circuit with said propeller pump, and thereby driven by surplus oil pumped by said propeller pump. 17. A turboprop engine as defined in claim 16, wherein said ejector pump pumps oil from a sump of a reduction gear box. 18. A turboprop engine as defined in claim 14, wherein said switching unit includes a valve which is responsive to a parameter indicative of the fluid pressure of said main source of pressurized fluid. 19. A turboprop engine as defined in claim 18, wherein said valve is responsive to the fluid pressure of said main source to disconnect said main source from said propeller pump inlet and connect said secondary source thereto when the fluid pressure of the main source is below a predetermined value. 20. A method for providing pressurised oil during in-flight shutdown of a variable pitch propeller engine, comprising the steps of: a) providing a propeller pump adapted to supply pressurized oil during engine operation from a main pressurised oil circuit to a propeller pitch actuation system, upon in-flight shutdown of the engine, b) selectively connecting the propeller pump to a secondary pressurized fluid circuit, the circuit including a an ejector pump operable independently of operation of the engine to supply pressurised oil during said engine shutdown and c) using surplus propeller pump flow as a motive fluid to operate the ejector pump. 21. The method of claim 20 wherein the method further comprises the step of connecting an outlet of the ejector pump to an inlet of the propeller pump, and wherein the step of selectively connecting further comprises selectively connecting an outlet of the propeller pump to an inlet of the ejector pump. 22. A backup system for providing pressurised oil to a propeller control system during an in-flight shutdown of an engine, the propeller control system including a propeller pump having an outlet connected to a propeller control unit and an inlet connected to a supply of pressurised oil during engine operation, the backup system comprising a secondary pump connected to the propeller pump inlet and adapted to selectively supply said propeller pump inlet with a flow of pressurized oil during said in-flight engine shutdown, wherein said valve is responsive to fluid pressure at the inlet of the propeller pump for connecting said secondary pump to the inlet of the propeller pump when fluid pressure at the inlet of the propeller pump is below a predetermined value indicative of said in-flight engine shutdown.
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이 특허에 인용된 특허 (16)
Lampeter Robert J. (Windsor CT) Duchesneau Jerome G. (Andover CT), Blade pitch change control system.
Miller Edwin K. (West Chester OH) Roberts Robert L. (West Chester OH) Hora Petr (West Chester OH) Joyce David L. (West Chester OH) Mears John S. (Cincinnati OH), Propeller pitch control.
Francois Roland C. (Cabries FRX), Safeguard system of a speed increasing/reducing mechanical assembly, especially of the helicopter “gear box”type, in c.
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