ACTUATING SYSTEM FOR ACTUATING A FOLDABLE WING TIP PORTION OF A WING FOR AN AIRCRAFT

Abstract

An actuating system for pivoting a wing tip section (13) about a fixed wing base section (11), and including a heating arrangement (33) positioned and adapted to be operable to heat at least one portion of an actuating arrangement (23) that pivots the wing tip section such that at least for ambient temperatures below a predetermined temperature the required work to be effected by the actuator (25) when moving the second coupling part (31) between the first position and the second position is lower than without heating the at least one portion.

Claims

1. An actuating system for a wing arrangement for an aircraft, wherein the wing arrangement includes a wing with a base section having a first end portion adapted to be secured to a fuselage of the aircraft and an opposite second end portion, and a tip section including a third end portion and an opposite fourth end portion, wherein the third end portion is pivotably connected to the second end portion such that the tip section is pivotable about a pivot axis between a deployed position and a stowed position in which a spanwise length of the wing is smaller than in the deployed position, wherein the actuating system comprises: an actuating arrangement including an actuator, a first coupling part and a second coupling part, wherein the first coupling part is adapted to be coupled to the base section, the second coupling part is adapted to be coupled to the tip section, and the actuator is operable to move the second coupling part with respect to the first coupling part between a first position and a second position such that when the first coupling part is coupled to the base section and the second coupling part is coupled to the tip section wherein the actuating arrangement is operable to selectively move, by operating the actuator, the tip section between the deployed position and the stowed position, wherein in the first position of the second coupling part the tip section is in the deployed position and in the second position of the second coupling part the tip section is in the stowed position, and a heating arrangement is positioned and adapted to be operable to heat at least one portion of the actuating arrangement such that at least for ambient temperatures below a predetermined temperature the required work to be effected by the actuator when moving the second coupling part between the first position and the second position is lower than without heating the at least one portion of the actuating arrangement.

2. The actuating system according to claim 1, wherein the actuating arrangement comprises a transmission having an input coupled to and driven by the actuator, and an output coupled to and driving at least one of the first coupling part and the second coupling part.

3. The actuating system according to claim 2, wherein the transmission or a part of the transmission is one of the at least one portion of the actuating arrangement.

4. The actuating system according to claim 2, wherein the transmission includes a gearbox.

5. The actuating system according to claim 1, wherein the actuator or a part of the actuator is one of the at least one portion of the actuating arrangement.

6. The actuating system according to claim 1, wherein the at least one portion is a single portion constituted by the entire actuating arrangement.

7. The actuating system according to claim 1, wherein at least one of the at least one portion comprises a housing, and the heating arrangement is operable to heat the respective one of the at least one portion by heating the housing thereof.

8. The actuating system according to claim 1, wherein the actuator comprises an electric motor or a hydraulic actuator.

9. The actuating system according to claim 1, wherein the heating arrangement comprises one or more heating elements, each in thermal contact with one of the at least one portion of the actuating arrangement.

10. The actuating system according to claim 9, wherein the one or more heating elements comprise electric heating elements.

11. The actuating system according to claim 1, wherein the heating arrangement comprises one or more bleed air outlets, which are adapted to be coupled to a source of bleed air, and each of which is positioned such that in operation bleed air from the source of bleed air flowing out of the respective bleed air outlet comes in thermal contact with one of the at least one portion of the actuating arrangement.

12. The actuating system according to claim 11, wherein at least one of the at least one portion is at least partially surrounded by a sleeve such that there is a space between an inner surface of the sleeve and the respective one of the at least one portion, and wherein at least one of the bleed air outlets is in communication with the space such that in operation bleed air from the source of bleed air flowing out of the respective bleed air outlet flows into the space, comes into thermal contact with the respective one of the at least one portion, and subsequently flows out of an outlet of the space.

13. The actuating system according to claim 1, further comprising a control unit and at least one temperature sensor, wherein each of the at least one temperature sensor is associated with one of the at least one portion and configured to provide a sensor signal indicative of the temperature of the respective portion, and wherein the control unit is connected to the at least one temperature sensor and to the heating arrangement and is adapted to determine, based on the sensor signals received from the temperature sensors, whether the temperature of one or more of the at least one portion is below a predetermined trigger temperature, and to automatically control the heating arrangement to heat the respective one or more portions.

14. A wing arrangement for an aircraft comprising: a wing comprising a base section having a first end portion adapted to be secured to the fuselage of an aircraft and an opposite second end portion, and a tip section having a third end portion and an opposite fourth end portion, wherein the third end portion is pivotably connected to the second end portion such that the tip section is pivotable about a pivot axis between a deployed position and a stowed position in which the spanwise length of the wing is smaller than in the deployed position, and an actuating system, wherein the first coupling part is coupled to the base section and the second coupling part is coupled to the tip section such that the actuating arrangement is operable to selectively move, by operating the actuator, the tip section between the deployed position and the stowed position, wherein in the first position of the second coupling part the tip section is in the deployed position and in the second position of the second coupling part the tip section is in the stowed position.

15. An aircraft comprising: a fuselage, and a wing arrangement according to claim 14, wherein the first end portion of the base section is attached to the fuselage and the base section is arranged between the fuselage and the tip section.

16. An wing on an aircraft comprising: a fixed wing having an outer end in a spanwise direction; a foldable wing tip section having end section adjacent the outer end, wherein the foldable wing tip section is configured to pivot with respect to the fixed wing between an extended position and a stowed position and a spanwise length of the wing is shorter in the stowed position than in the extended position; an actuator connecting the outer tip of the fixed wing to the end section of the foldable wing tip section and configured to move the foldable wing tip section between the stowed and extended positions, wherein the actuator includes: a first coupling fixed to the fixed wing; a second coupling fixed to the foldable wing tip section; an actuator motor mounted to the first coupling and configured to generate mechanical kinetic energy to move the foldable wing tip section between the stowed and extended positions; a transmission mounted to the first coupling and coupled to the actuator motor, wherein the transmission transfers the mechanical kinetic energy generated by the actuator motor to the second coupling to move the foldable wing tip section; a housing enclosing the transmission; and a heater covering an outer surface of the housing and extending a perimeter of the housing.

17. The wing of claim 16, wherein the heater includes a mat covering the housing and the mat includes electrical heating elements which are configured to generate

18. The wing of claim 16, wherein the heater includes an insulating sleeve covering the housing, an annular bleed air duct between the insulating sleeve and the housing, and a bleed air conduit having a bleed air outlet at the duct and an inlet coupled to a source of bleed air.

19. The wing of claim 18, wherein the air duct includes an annular bleed air outlet adjacent the second coupling and oriented to direct bleed air flowing out of the annular bleed air duct onto the second coupling.

20. The wing of claim 16, wherein the heater includes conduits through which flow hydraulic

Description

DRAWINGS

[0026] In the following exemplary embodiments of the present invention will be explained in detail with reference to the drawings.

[0027] FIGS. 1a and 1b show a schematic top view of an aircraft for use in which the embodiments of the actuating system according to the present invention are adapted.

[0028] FIG. 2a shows a schematic perspective view of a first embodiment of an actuating system according to the present invention.

[0029] FIG. 2b shows a schematic cross-sectional view of the first embodiment of an actuating system according to the present invention.

[0030] FIG. 3a shows a schematic perspective view of a second embodiment of an actuating system according to the present invention.

[0031] FIG. 3b shows a schematic cross-sectional view of the second embodiment of an actuating system according to the present invention.

[0032] FIG. 4 shows a schematic cross-sectional view of a third embodiment of an actuating system according to the present invention.

DETAILED DESCRIPTION

[0033] FIGS. 1a and 1b show a schematic top view of an aircraft 1 which comprises two wing arrangements 3. The aircraft 1 also comprises a fuselage 5 extending along a longitudinal axis 7 which corresponds to the x-axis of the aircraft 1. Each of the wing arrangements 3 comprises a wing 9 that extends away from the fuselage 5, and each wing 9 comprises a base section 11 and a tip section 13. The base section 11, e.g., a fixed wing, has a first or inboard end portion 11a, which is configured or adapted to be coupled to the fuselage 5 and is shown to be coupled to the fuselage 5, and an opposite second or outboard end portion 11b spaced from the fuselage 5 by the remainder of the base section 11.

[0034] The tip section 13 of the wing 9 is pivotably connected to the second end portion 11b of the base section 11. More particularly, the tip section 13 extends away from the second or outboard end portion 11b of the base section 11 and comprises a third or inboard end portion 13a and an opposite fourth or outboard end portion 13b spaced from the base section 11 by the remainder of the tip section 13 (as can be seen in the insert of FIG. 1, which shows an outboard end region of one of the wings 9 in enlarged form). The fourth end portion may be provided by a part of a wing tip device 15, which itself is a part of the tip section 13. The third end portion 13a is pivotably mounted on or coupled to the second end portion 11 b of the base section 11 in such a manner that the tip section 13 is able to pivot between a deployed position and a stowed position about a pivot axis 17.

[0035] The pivot axis 17 generally extends in a direction between a leading edge and a trailing edge of the respective wing 9 and, in the example shown, parallel or essentially parallel to the longitudinal axis 7, i.e., in the flight direction. In the deployed position illustrated in FIG. 1 the tip section 13 extends essentially along the longitudinal axis of the base section 11, and in the stowed position the tip section 13 is angled upwardly with respect to the longitudinal axis of the base section 11, so that the spanwise length of the wing 9 is decreased. Thus, in the deployed position the fourth end portions or the outermost outboard ends of the tip sections 13 of the wings 9 have a larger distance than in the stowed position, so that the wingspan of the aircraft 1 can be selectively decreased by moving the tip sections 13 of the wings 9 from the deployed position into the stowed position in order to allow for the use of infrastructure adapted to aircraft of such reduced wingspan and in order to save on airport fees, and increased in order to allow for reduced fuel consumption during flight.

[0036] In order to effect the pivotal movement of the tip section 13 between the deployed and the stowed positions, each of the wing arrangements 3 comprises an actuating system 21. The actuating system 21 is shown only very schematically in the insert of FIG. 1, and two particular embodiments of the actuating system 21 are schematically illustrated in some more detail in FIGS. 2 and 3. The aircraft 1 also comprises a control unit 19, which may be part of the central control system of the aircraft 1. The control unit 19 is adapted to control at least part of the operation of the actuating system 21.

[0037] The actuating system 21 illustrated in FIGS. 2a and 2b comprises an actuating arrangement 23 which, in turn, comprises an actuator 25 in the form of an electric or rotational hydraulic motor, and an actuating unit 27, which is or includes a gearbox and is driven by the motor 25. The actuating arrangement 23 further comprises a first coupling part 29, inside of which transmission or coupling elements for drivingly coupling the actuator 25 to the actuating unit 27, and a second coupling part 31. In the illustrated embodiment, the first coupling part 29 is fixedly connected to the base section 11, and the second coupling part 31 drivingly engages the tip section 13, i.e. is drivingly coupled to the tip section 13, in a manner not illustrated in detail in the Figures. For example, the second coupling part 31 may be a gear of the actuating unit 27. Alternatively, the second coupling part 31 may for example be a toothed element fixedly secured to the tip section 13 and engaged by a gear of the actuating unit. Generally, different arrangements and configurations of the first and second coupling parts 29, 31 are possible. In any case, by operation of the motor 25 the tip section 13 is selectively moved between the deployed position and the stowed position by effecting a corresponding relative movement between the first and second coupling parts 29, 31.

[0038] The actuating system 21 further comprises a heating arrangement 33, which comprises an electric heating element in the form of a heating mat 35 which is connected to a source of electrical energy (not shown) of the aircraft 1 via an electric line 37. The heating mat 35 circumferentially extends around a substantial portion of a generally cylindrical housing 39 of the actuating unit or gearbox 27 and is in thermal contact with an outer surface of the housing 39 (see the cross-sectional view of FIG. 2b). Thus, the heating mat 35 is operable to heat the actuating unit 27, which therefore constitutes a portion of the actuating arrangement 23 which is heatable by the heating arrangement 33. Due to the heating an increase of a reaction load of the actuating unit or gearbox 27 at decreasing temperatures can be counteracted.

[0039] In an alternative embodiment illustrated in FIGS. 3a and 3b the actuating system 21 is largely of the same construction as the actuating system 21 of FIGS. 2a and 2b, so that reference is made to the description of the embodiment of FIGS. 2a and 2b. However, instead of a heating mat the heating arrangement 33 comprises a bleed air outlet 43 at the terminal end of a bleed air conduit 45 coupled to a source of bleed air in the aircraft 1, such as an outlet from a compressor section on a gas turbine engine 10 on the aircraft. The thermally insulating sleeve 47 which circumferentially extends around the housing 39 of the actuating unit or gearbox 27. As can be best seen in FIG. 3b, a circumferential space 49 is present between the inner surface of the sleeve 47 and the outer circumferential surface of the housing 39. The bleed air outlet 43 is arranged such that bleed air exiting the bleed air outlet 43 enters the space 49 at one of the axial ends thereof flows through the space 49 in the axial direction of the housing 39 and sleeve 47 in thermal contact with the housing 39, and exits the space 49 at the opposite axial end, which constitutes an outlet 51 for bleed air. This is illustrated by the arrows in FIG. 3a. Thus, the bleed air can be utilized to heat the actuating unit 27, which therefore constitutes a portion of the actuating arrangement 23 which is heated by the heating arrangement 33. Due to the heating an increase of a reaction load of the actuating unit or gearbox 27 at decreasing temperatures can be counteracted.

[0040] FIG. 4 shows the actuating system 21, which has a similar construction to the actuating system 21 of FIGS. 2a and 2b, so that reference is made to the description of the embodiment of FIGS. 2a and 2b. However, instead of a heating mat the heating arrangement 33 comprises a conduit or line 55 for conducting either heated hydraulic fluid through oil (not illustrated) present in the interior of the actuating unit or gearbox 27 or electric current to a resistive heating element 59 in the interior of the actuating unit or gearbox 27. For this purpose, the conduit or line 55 is coupled to a source 57 of the heated hydraulic fluid or electric current, respectively. The source 57 may be, e.g., a hydraulic line of the aircraft 1, for which the conduit 55 in effect constitutes a hydraulic leakage, or a power supply or power supply line of the aircraft 1. In the case of a conduit 55 conducting heated hydraulic fluid the conduit 55 constitutes a part of a heat exchanger adapted to transfer heat from the heated hydraulic fluid to the oil of the actuating unit or gearbox 27.

[0041] In all three embodiments illustrated in FIGS. 2a, 2b, 3a, 3b and 4 a temperature sensor 41 is arranged in thermal contact with the housing 39 and is connected to the control unit 19, so that the control unit 19 can determine the temperature of the housing 39. The control unit 19 is configured and adapted such that when the determined temperature falls below a predetermined trigger temperature, which may be, e.g., 0 C., the control unit 19 automatically operates the heating arrangement 33 to heat the housing 39 and, thereby, the actuating unit or gearbox 27.

[0042] An actuating system for a wing arrangement 3 for an aircraft 1. The arrangement 3 includes a wing 9 comprising a base section 11 having a first end portion 11 a adapted to be secured to the fuselage 5 of an aircraft 1 and an opposite second end portion 11b, and a tip section 13 having a third end portion 13a and an opposite fourth end portion 13b, wherein the third end portion 13a is pivotably connected to the second end portion 11b such that the tip section 13 is pivotable about a pivot axis 17 between a deployed position and a stowed position in which the spanwise length of the wing 9 is smaller than in the deployed position. The actuating system 21 comprises an actuating arrangement 23 which comprises an actuator 25, a first coupling part 29 and a second coupling part 31. The first coupling part 29 is adapted to be coupled to the base section 11, the second coupling part 31 is adapted to be coupled to the tip section 13 and the actuator 25 is operable to move the second coupling part 31 with respect to the first coupling part 29 between a first position and a second position, such that when the first coupling part 29 is coupled to the base section 11 and the second coupling part 31 is coupled to the tip section 13 the actuating arrangement 23 is operable to selectively move, by operating the actuator 25, the tip section 13 between the deployed position and the stowed position. In the first position of the second coupling part 31 the tip section 13 is in the deployed position, and in the second position of the second coupling part 31 the tip section 13 is in the stowed position. The actuating system 21 further comprises a heating arrangement 33 which is positioned and adapted to be operable to heat at least one portion of the actuating arrangement 23 such that at least for ambient temperatures below a predetermined temperature the required work to be effected by the actuator 25 when moving the second coupling part 31 between the first position and the second position is lower than without heating the at least one portion.

[0043] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.