Aircraft propulsive power unit

• US 20030102405A1
• Filed: 09/30/2002
• Published: 06/05/2003
• Est. Priority Date: 10/11/2001
• Status: Active Grant

• Current Assignee: MHI Rj Aviation ULC (Mitsubishi Heavy Industries, Ltd.)
• Original Assignee: Short Brothers PLC (Spirit Aerosystems Holdings Incorporated)
• Inventors: McEvoy, Finbarr
• Granted Patent: US 6,869,046 B2
• Time in Patent Office: Days
• US Class Current: 244/54
• CPC Class Codes: B64D 29/04 associated with fuselages
• CPC Class Codes: B64D 29/08 Inspection panels for power plants

Abstract

An aircraft having a propulsive power unit supported in a fuselage mounted configuration and including an engine and a nacelle structure housing the engine. The nacelle structure is provided with upper and lower displaceable nacelle portions, such as thrust reverser cowls and fan cowl doors which are displaceable between closed dispositions which they occupy during operational conditions of the aircraft and open dispositions which they take up to provide access to engine components. The upper and lower nacelle portions are so mounted as to be displaceable to their open and closed dispositions in movements in which one is assisted by gravitational force and the other is displaced against gravitational force. A force transfer mechanism is provided for transfer during opening and closing movements of the nacelle portions of gravitational force assisting displacement of one of the nacelle portions to assist in displacement of the other nacelle portion being displaced against gravitational force.

Claims

1. An aircraft having a propulsive power unit including an engine and a nacelle structure housing the engine, the nacelle structure including first and second displaceable nacelle portions each of which is displaceable between a closed disposition which it occupies during operational conditions of the aircraft and an open disposition which it takes up to provide access to engine components, the first and second nacelle portions being so mounted that the first nacelle portion is displaceable to its open disposition in an opening movement in which it is assisted by gravitational force acting upon it and is displaceable to its closed disposition in a closing movement against gravitational force acting on it and the second nacelle portion is displaceable to its open disposition in an opening movement against gravitational force acting on it and is displaceable to its closed disposition in a closing movement in which it is assisted by gravitational force acting on it, characterised in that force transfer means provide for a predetermined transfer during opening movements of the nacelle portions of gravitational force acting on the first nacelle portion to assist displacement of the second nacelle portion to its open disposition and during closing movements of the nacelle portions gravitational force acting on the second nacelle portion to assist displacement of the first nacelle portion to its closed disposition.

2. An aircraft according to claim 1, comprising propulsive power unit support means to support the aircraft propulsive power unit, a first pivotal mounting on the support means to provide for pivotal opening and closing movements of the first nacelle portion and a second pivotal mounting on the support means to provide for pivotal opening and closing movements of the second nacelle portion.

3. An aircraft according to claim 2, wherein the first nacelle portion is an upper nacelle portion which extends in arcuate form round an upper region of the nacelle structure from its pivotal mounting on the support means at one side of the nacelle structure to an attachment position at the other side of the nacelle structure and wherein the second nacelle portion is a lower nacelle portion which extends in arcuate form round a lower region of the nacelle structure from its pivotal mounting on the support means at the one side of the nacelle structure to an attachment position at the other side of the nacelle structure

4. An aircraft according to claim 3 wherein the force transfer means comprises a force transfer link mechanism having a pivotal arm which is pivotally connected at one end to one of the nacelle portions at an offset pivotal location which is radially offset from the pivotal mounting of that nacelle portion on the support means and which is pivotally connected at its other end to the other of the nacelle portions at an offset pivotal location radially offset from the pivotal mounting of that nacelle portion on the support means and wherein the disposition of the offset pivotal locations on the nacelle portions and the form of the pivotal arm are such as to cause the predetermined transfer through the pivotal arm of gravitational force during opening and closing movements of the nacelle portions.

5. An aircraft according to claim 4, wherein the link mechanism includes a fixed arm fixedly mounted on one of the nacelle portions and extending therefrom, and wherein the offset pivotal location of the pivotal arm on that nacelle portion is provided on the fixed arm at the end thereof.

6. An aircraft according to claim 5 wherein the pivotal arm includes adjustment means to adjust the length of the arm.

7. An aircraft according to claim 4 wherein the link mechanism is a first link mechanism with the fixed arm mounted on the upper nacelle portion and wherein the force transfer means includes a second link mechanism of the same form as the first link mechanism with its fixed arm fixedly mounted on the lower nacelle portion.

8. An aircraft according to claim 7 wherein the first and second link mechanisms are of identical form and share the predetermined transfer of gravitational force during the opening and closing movements of the nacelle portions.

9. An aircraft according to claim 3, wherein the force transfer means comprises a force transfer gear mechanism including a first gear segment having an arcuate toothed track with a centre of curvature at the pivotal mounting of the upper nacelle portion on the support means and a second gear segment having an arcuate toothed track with a centre of curvature at the pivotal mounting of the lower nacelle portion on the support means, and wherein the gear segments are so positioned on the nacelle portions as to maintain the toothed tracks in driving engagement with each other, thereby to cause the predetermined transfer of gravitational force during opening and closing movements of the nacelle portions.

10. An aircraft according to claim 3 wherein the force transfer means is a force transfer fluid responsive mechanism comprising first and second fluid responsive components, wherein the first component is pivotally connected at one end to the upper nacelle portion at an offset pivotal location which is radially offset from the pivotal mounting of that nacelle portion on the support means and at the other end is pivotally connected to the support means at an offset pivotal mounting offset from the pivotal mounting of that nacelle portion on the support means and the second component is pivotally connected at one end to the lower nacelle portion at an offset pivotal location which is radially offset from the pivotal mounting of that nacelle portion on the support means and at the other end is pivotally connected to the support means at an offset pivotal mounting radially offset from the pivotal mounting of that nacelle portion on the support means, wherein each component is responsive to flow of fluid applied to it, wherein fluid flow connections are provided between the components to provide for fluid flow to and from them and wherein the dispositions of the pivotal connections of the two components, the fluid response characteristics of the two components and the fluid flow connections between them are such as to cause the predetermined transfer of gravitational force imposed on one nacelle portion to the other nacelle portion during opening and closing movements of the nacelle portions.

11. An aircraft according to claim 10, wherein each fluid responsive component comprises a cylinder element and a displaceable piston element displaceable within the cylinder element and wherein the fluid flow connections provide for fluid flow to and from the cylinder element on each side of the piston element of each component from and to the cylinder element on the other side of the piston element of the other component.

12. An aircraft according to claim 11 wherein each fluid responsive component is responsive to hydraulic fluid.

13. An aircraft according to claim 3 wherein the upper nacelle portion in its open disposition is such that the upper nacelle portion during its opening movement passes top dead centre in relation to its pivotal mounting on the support means, and wherein biasing means are provided to minimise and optimise the hand load required from an operator during a closing movement in which the upper nacelle portion is required to reach and pass through top dead centre.

14. An aircraft according to claim 13, wherein the biasing means comprises a spring which is pivotally connected at one end to one of the nacelle portions at an offset pivotal location radially offset from the pivotal mounting of that nacelle portion on the support means and which is pivotally connected at its other end at a pivotal location on the other nacelle portion or on the support means.

15. An aircraft according to claim 3 wherein the nacelle structure includes upper and lower thrust reverser cowls pivotally mounted on the support means and wherein the upper and lower nacelle portions are the upper and lower thrust reverser cowls of the nacelle structure.

16. An aircraft according to claim 3 wherein the nacelle structure includes upper and lower fan cowl doors and wherein the upper and lower nacelle portions are the upper and lower fan cowl doors of the nacelle structure.

17. An aircraft according to claim 3 wherein the nacelle structure includes upper and lower thrust reverser cowls pivotally mounted on the support means and upper and lower fan cowl doors pivotally mounted on the support means, wherein the upper reverser cowl and the upper fan cowl door are connectable to each other to form a displaceable upper cowl assembly and the lower reverser cowl and the lower fan cowl door are connectable to form a lower cowl assembly and wherein the upper and lower nacelle portions are the upper and lower cowl assemblies.

18. An aircraft according to claim 3 wherein the support means is a support boom which is supported at one end by an aircraft part and which extends laterally to support the propulsive power unit outboard of the aircraft part.

19. An aircraft according to claim 18 wherein the aircraft part is a fuselage of the aircraft and the support boom extends outboard of the fuselage.

20. An aircraft according to claim 19 wherein the support boom extends outwardly from the aircraft fuselage at a predetermined dihedral.