Landing flap drive system

A landing flap drive system, in one example, includes a first drive motor for operating a landing flap. In this arrangement, the landing flap drive system is integrated in a track of the landing flap such that final assembly and integration of the system are facilitated to a significant extent.

FIELD OF THE INVENTION

The field relates to landing flap systems for aircraft.

BACKGROUND OF THE INVENTION

Today's landing flap drive systems, comprise a central drive with a central shaft transmission to the drive stations. Apart from these, for reasons of redundancy, there are also solutions involving two shaft arrangements, wherein the flaps of the left-hand and the right-hand wing are mechanically coupled together. These are drive systems in which generation of the mechanical drive performance takes place so as to be locally separated from the power takeoff at the individual drive stations that are distributed along the wing.

In landing flap systems with a central drive arrangement, the drive motor is located in the fuselage of the aircraft. The mechanical drive output is fed by way of a central shaft arrangement to the actuators of the respective drive stations. The actuators are linear drives or rotary drives. Since the shaft arrangement, starting from the fuselage, has to be provided right up to the outer landing flap, structural leadthroughs, deflection gear arrangements and universal joints or cardan joints are necessary. The installation expense of the final assembly of such a system may be considerable.

SUMMARY OF THE INVENTION

It is an object to provide for an improved landing flap drive system for aircraft.

According to an embodiment, a landing flap drive system for an aircraft comprises a first drive motor for operating a landing flap, wherein the landing flap drive system is integrated in a track of the landing flap.

By integrating the entire drive system in the track, the installation and the integration of the landing flap drive system in the aircraft may be facilitated to a significant extent. Furthermore, the production expenditure or pre-installation expenditure may be reduced because all the drive components can be integrated in the track beforehand, in the factory, prior to final assembly of the track.

According to a further embodiment, the landing flap drive system further comprises a step-down gear arrangement to reduce the operational speed of the landing flap.

In this way, an optimal operation point may be selected, depending on the selected motor speed.

According to a further embodiment, the landing flap drive system further comprises a second drive motor for operating the landing flap.

In this way, drive redundancy may be provided which may further enhance system safety and may minimise the risk of failure. Furthermore, for example, when a considerable load is experienced, the second drive motor may be switched on if necessary so as to improve the drive performance.

According to a further embodiment, the landing flap drive system further comprises a brake device for fixing the landing flap.

The brake device may be used in a supportive manner in that it absorbs, or compensates for, a compressive force that acts on the landing flap and thus relieves the drive motor. Furthermore, the brake device may be used for finally setting the landing flap, if the landing flap no longer has to be moved.

According to a further embodiment, the landing flap drive system further comprises a safety load path to ensure structural integrity, wherein the safety load path is designed to hold the landing flap in the case of structural failure.

According to a further embodiment, the landing flap drive system further comprises an actuator for activating the landing flap, wherein the actuator is driven by the first drive motor.

The actuator, for example, may be connected between the drive motor and the landing flap in order to transmit the drive force from the motor to the flap. For example, the actuator may be designed as a failsafe spindle or as a rotary actuator.

According to a further embodiment, the landing flap drive system further comprises a first attachment region for attaching the landing flap drive system to a wing of the aircraft, and a second attachment region for attaching the landing flap drive system to the landing flap.

In this way, the effort required for installing the landing flap drive system during final assembly may be considerably reduced in that the landing flap drive system that is integrated in the track is attached to the first attachment region on the wing of the aircraft. Essentially there may be no need for any more extensive installation beyond this. On the second attachment region, the landing flap drive system may simply be connected to the landing flap such that the landing flap can be operated.

According to a further embodiment, the landing flap drive system further comprises a first interface for connecting the landing flap drive system to an energy supply, and a second interface for connecting the landing flap drive system to a signal line for controlling the landing flap drive system.

According to this embodiment, the interfaces may be installed correspondingly already in the context of preassembly or pre-installation such that during final assembly, simple connection of the supply lines or signal lines to the landing flap drive system is all that is required.

According to a further embodiment, synchronisation of the first and the second drive motor takes place electronically without there being a need to provide mechanical coupling between the first drive motor and the second drive motor.

Furthermore, according to a further embodiment, synchronisation between various landing flap drive systems or between drive motors that each belong to different landing flap drive systems may be provided, wherein such synchronisation takes place on an electronic basis without mechanical coupling of the different landing flap drive systems.

According to a further embodiment, the first drive motor is an electromechanical motor.

According to a further embodiment, a track for a landing flap for an aircraft is disclosed, wherein the track comprises an integrated landing flap drive system.

The landing flap drive system, for example, may be integrated in the track prior to final assembly of the track. Such complete integration in the track may considerably reduce the effort required for assembly. There may be no need to provide structural leadthroughs through the fuselage and the trailing edge of the wing and the associated deflection gear and universal joints of the shaft arrangement that are necessary in centrally driven landing flaps. During final assembly, a track that is equipped with all the system components may only need to be attached underneath the wing and may need to be connected to the supply lines and signal lines and to the flap structure. Furthermore, the design space problems of redundant drives to be installed on the trailing edge of the wing may be solved in this way.

According to a further embodiment, an aircraft with an integrated landing flap drive system is provided.

According to a further embodiment, the use of an integrated landing flap drive system in an aircraft is provided.

Further embodiments are stated in the subordinate claims.

Below, preferred embodiments are described with reference to the figures.

In the following description of the figures the same reference characters are used for identical or similar elements.

DETAILED DESCRIPTION

The examples described and drawings rendered are illustrative and are not to be read as limiting the scope of the invention as it is defined by the appended claims.

FIG. 1shows a diagrammatic view of a landing flap system. Today's landing flap drive systems, generally speaking, comprise a central drive101arranged in the fuselage, and a central shaft arrangement102. The central shaft arrangement102is used to transmit the driving power from the motor101to the individual landing flaps103,104,105,106,107,108. This may require extensive installation work such as, for example, leadthroughs in the fuselage.

FIG. 2shows a diagrammatic view of a further landing flap system. As shown inFIG. 2, in this arrangement two shaft arrangements102,202have been provided for reasons of redundancy, wherein the flaps106,107of the left-hand wing, and the flaps of the right-hand wing (not shown inFIG. 2) are mechanically coupled to each other.

The landing flap systems shown inFIGS. 1 and 2are drive systems in which the generation of the mechanical drive performance (by way of the motor unit201) is locally separated from the power takeoff on the individual drive stations that are distributed along the wing.

FIG. 3shows a diagrammatic view of a landing flap drive system and a schematic landing flap309, with individual drives301,302and a connecting shaft303and brake304. In this arrangement the inner and outer landing flaps may be moved independently of each other. In this solution the redundant drives of a flap segment may either be coupled by means of a shaft segment (seeFIG. 3), or for each drive station401,402may be driven by independent drives301,302(seeFIG. 4).

The reference characters305,306designate the RA flap drive link track2or track1.

In the case of landing flap systems with a central drive arrangement, the drive motor is located in the fuselage of the aircraft. The mechanical drive performance is fed by way of a central shaft arrangement to the actuators, which are, for example, designed in the shape of linear actuators or rotary actuators and which are associated with the respective drive stations. Since the shaft arrangement has to lead from the fuselage right to the outer landing flap, structural leadthroughs, deflection gearing and universal joints are necessary. The installation expenditure of the final assembly of such a system is very considerable.

Individual drives may significantly improve this situation because in this way large parts of the central drive arrangement can be done without. Furthermore, individual drives may provide the option of improved functional flexibility.

For example, according to an embodiment, there is no need to provide a shaft arrangement between both drives. In order to achieve good system availability and system safety, redundant drives may be installed for individual landing flaps or groups of landing flaps. Since installation of the drives on the trailing edge of the wing or centrally in the fuselage may result in installation problems and increased installation expenditure (for example, because the design space on the trailing edge of the wing is limited or because corresponding leadthroughs etc. have to be provided), essentially the entire drive system is integrated in the track of the aircraft. Furthermore, this may make it possible to pre-integrate all the drive components in the track.

FIG. 5Ashows a lateral view505andFIG. 5Ba top view500of a track-integrated landing flap drive system with a rotary actuator according to one embodiment of the present invention. As shown inFIG. 5AandFIG. 5Bthe landing flap drive system comprises a first drive motor501for operating the landing flap107. In this arrangement the landing flap drive system is completely integrated in the track509of the landing flap107. The motor unit501is controlled by way of motor electronics503. The motor electronics503are connected by way of corresponding interfaces to a signal line for controlling the landing flap drive system. Furthermore, an interface for connecting the landing flap drive system to an energy supply is provided. The supply interface and the signal line interface can for example be arranged in the supply connection504, which during final installation of the track509is connected at the wing of the aircraft to a corresponding counter interface.

Furthermore, an actuator502, designed in the form of a rotary actuator502, is provided. In this arrangement, the actuator502is driven by the motor unit501, wherein the actuator502operates the landing flap107by way of corresponding mechanical operating means506in conjunction with linkages507.

As shown in the top view500ofFIG. 5A, furthermore, a safety load path508is provided, which is used to ensure structural integrity. For example, the safety load path508can be designed so that in the case of structural failure of the landing flap drive system the landing flap107is held in its position.

According to an embodiment the landing flap drive system comprises individual electromechanical drives501. In this arrangement the landing flap drive system comprises the drive motors501; a step-down gear arrangement511(if necessary), which for example may be integrated in a rotary actuator; an actuator502which may be a rotary actuator; a brake device, which for example forms part of the drive mechanism506; a safety load path508; sensors and motor electronics503.

Depending on the required availability, one or two motors may be used for each drive station. It may be also possible to provide additional motors so as to further enhance the redundancy and thus the system safety or the provision of output.

Depending on the selected motor speed in the optimum work point, for example, a step-down gear arrangement is installed. In order to set the landing flap drive system, a brake device can be provided. In this arrangement, both the step-down gear arrangement and the brake device are also integrated in the track509. For example, brakes or gears/actuators with self-locking action can be used. If due to ensuring structural integrity, a safety load path508is necessary, then, this safety load path508can also be integrated in the track509.

It should be noted that the detailed design of the system depends on system requirements such as, for example, availability, flexibility of functions etc. as well as on other boundary conditions such as, for example, the number of tracks for each flap segment.

The interfaces of the track509with the integrated landing flap drive system and the wing of the aircraft or its landing flaps are provided by the structural attachments of the track to the wing in the form of a first attachment region510and the connection of the landing flap drive system to the landing flap in the form of a second attachment region506,507. Furthermore, interfaces for supplying energy to the drives501and to the signal line504are provided. The first attachment region can of course also be arranged at some other position on the track509.

Synchronisation of the drives501in the tracks509of a landing flap segment takes place electronically. According to one embodiment, to this effect, no mechanical coupling between the first drive motor501and a second drive motor is provided.

For example, for the purpose of synchronisation, position sensors can be provided on the actuators502, the motors501or the mechanical operating elements506in order to carry out position determination. These sensors, for example, may be connected to the motor electronics503and to corresponding evaluation electronics that can also be integrated in the motor electronics. This does not require mechanical coupling of the different motor units501.

FIG. 6AandFIG. 6Bshows a further exemplary embodiment of a track-integrated landing flap drive system with a failsafe spindle drive602. A lateral view605and a top view600of the landing flap drive system are shown.

As shown inFIG. 6Aand inFIG. 6B, in this case a fail-safe spindle is selected as an actuator so that there is no need for an additional safety load path.

FIG. 7shows an embodiment of a track-integrated landing flap drive system with a simple spindle drive so that a further safety load path508in the form of a gear tooth arrangement is arranged on the track509. Should a system failure be experienced, the safety load path508can hold the landing flap.

It should be noted that further embodiments may be possible. The fundamental principle may always consist of all the components of the drive system being arranged in, or on, the track509.

With complete integration in the track509, the installation expenditure may be significantly reduced. Furthermore, there may be no need to provide the structural leadthroughs through the fuselage and the trailing edge of the wing, which structural leadthroughs are necessary in the case of centrally-driven landing flaps, nor may there be any need for deflection gears and universal joints of the shaft arrangement. During final assembly a track equipped with all the system components may only need to be attached underneath the wing and may need to be connected to the supply lines, the signal lines and the flap structure. Furthermore, the problem of finding installation space in the case of redundant drives to be installed at the trailing edge of the wing may be solved in this way.

In addition it should be pointed out that “comprising” does not exclude other elements or steps, and “a” or “an” does not exclude a plurality. Furthermore, it should be pointed out that characteristics or steps which have been described with reference to one of the above embodiments can also be used in combination with other characteristics or steps of other embodiments described above. Reference characters in the claims are not to be interpreted as limitations.

Alternative combination and variations of the examples provided will become apparent based on this disclosure. It is not possible to provide specific examples for all of the many possible combinations and variations of the embodiments described, but such combinations and variations may be claims that eventually issue.