Patent Description:
Most known slat actuation architectures have a static geared rotary actuator (GRA) that drives the slat via a pinon. For some applications, like e.g. droop nose or for space allocation (e.g. short curved track principle) lever bearing assemblies are preferred.

<CIT> discloses a typical GRA for a leading edge of an aircraft.

<CIT> discloses a wing for an aircraft, comprising a main wing, a slat, and a connection assembly for movably connecting the slat to the main wing. The connection assembly comprises a drive unit provided at the main wing and connected to the slat for initiating movement of the slat. The drive unit comprises a plurality of drive stations spaced apart from one another in the wing span direction.

<CIT> discloses a panel device for modifying airflow about a wing of an aircraft. The panel device comprises a plurality of independently operable panel sub-sections. The panel sub-section is coupled to the trailing edge of the wing by a linkage mechanism. The linkage mechanism comprises an actuator coupled to a trapezoidal frame by a mechanical linkage. The actuator is fixed to the wing at the trailing edge. Activation of the actuator is operable to raise and lower the relative position of the panel sub-section with respect to the wing.

<CIT> discloses a high-lift system for aircraft wings. The leading edge device comprises a worm and linkage system in which pivoted scissors are pivoted at one of their ends. The scissors connect to a lower flap door and a fixed bracket respectively. At their other ends the scissors connect to a nut-and-bracket device driven by a turning screw. The turning screw results in translation of the nut-and-bracket device, angular displacements of the scissors, and motion of the lower flap door about its pivotal axis.

<CIT> discloses a flap connected to a wing by a geared hinge. Extension or retraction of the flap is accomplished by an actuating and drive mechanism arranged on the flap. Upon command of an associated remotely positioned control means the actuating mechanism will via the drive mechanism drive the geared hinge connection for moving the flap into a predetermined position in reference to the wing surface.

It is the object of the invention to improve an actuator arrangement for high-lift devices.

The invention provides a wing assembly for an aircraft, the wing assembly comprising a fixed leading edge member, a high-lift device movably attached to the fixed leading edge member, and an actuator arrangement, the actuator arrangement comprising:.

so as to allow movement of the high-lift device between a fully retracted position and a fully extended position, wherein the fixed leading edge member has an inner cavity that is defined at least in part by an outer skin and a rib, wherein the actuator arrangement is configured for extending and retracting the high-lift device, the actuator assembly including at least one geared rotary actuator, wherein the actuator assembly is configured such that the geared rotary actuator is movable during extending and retracting of the high-lift device between a fully retracted position, in which the geared rotary actuator is predominantly accommodated within the inner cavity, and a fully extended position, in which the geared rotary actuator is predominantly positioned outside the inner cavity. The geared rotary actuator is rotatable about a rotational axis that is defined by the mounting point of the fixed leading edge lever.

Preferably, the geared rotary actuator is movable along a circular arc section in a forward direction during extending of the high-lift device and/or in an aft direction during retracting of the high-lift device.

Preferably, the geared rotary actuator, when in the fully retracted position, is wholly accommodated within the inner cavity.

Preferably, the geared rotary actuator, when in the fully extended position, is wholly positioned outside the inner cavity.

Preferably, the geared rotary actuator assembly includes at least two geared rotary actuators and two geared rotary actuators each are grouped together into a respective geared rotary actuator group for driving one high-lift device.

Preferably, the geared rotary actuator arrangement further comprises a drive unit providing mechanical power for driving the geared rotary actuator assembly Preferably, the geared rotary actuator assembly includes a spanwise drive train having at least one spanwise straight drive shaft, which mechanically couples two adjacent geared rotary actuators.

Preferably, the geared rotary actuator assembly includes a first geared rotary actuator and a second geared rotary actuator, wherein the first geared rotary actuator is mechanically coupled to the drive unit.

Preferably, the first geared rotary actuator is mechanically coupled to the drive unit via a pivotable drive shaft.

Preferably, the second geared rotary actuator is mechanically coupled to the first geared rotary actuator via a spanwise straight drive shaft.

Preferably, the drive unit is arranged spanwise between adjacent geared rotary actuators associated with one high-lift device.

Preferably, the drive unit is arranged on the same axis as the geared rotary actuator in a spanwise direction.

Preferably, the drive unit is arranged aft of the geared rotary actuator.

Preferably, the drive unit is arranged below the geared rotary actuator.

Preferably, the drive unit is arranged aft and below of the geared rotary actuator.

Preferably, the drive unit is arranged adjacent to the geared rotary actuator in a spanwise direction or chordwise direction.

Preferably, the drive unit is configured to be arranged predominantly, in particular entirely, within an upper half of the inner cavity in the fully retracted position.

Preferably, the drive unit is configured to be arranged partially, in particular predominantly, within a lower half of the inner cavity in the fully extended position.

Preferably, the drive unit is configured to be arranged within the inner cavity, when in the fully retracted position, in the fully extended position and when moving between said positions.

Preferably, the drive unit is configured to be arranged predominantly, in particular entirely, within a lower half of the inner cavity in the fully retracted position.

Preferably, the drive unit is configured to be arranged partially outside inner cavity in the fully extended position.

Preferably, the drive unit is configured to be arranged to protrude downward through a cut-out of the fixed leading edge member.

Preferably, the drive unit is attached to the actuator assembly, so as to be simultaneously movable.

Preferably, the drive unit has at least one motor for driving the geared rotary actuator.

Preferably, the drive unit has at least one electric motor for driving the geared rotary actuator.

Preferably, the drive unit has at least one hydraulic motor for driving the geared rotary actuator.

Preferably, one or each motor is mechanically coupled to two adjacent geared rotary actuators associated with one high-lift device, in particular via a spanwise straight drive shaft.

Preferably, one or each motor is arranged aft of and adjacent to the geared rotary actuator when viewed in a top view.

Preferably, one or each motor is arranged aft of and below the geared rotary actuator and adjacent to the geared rotary actuator when viewed in a top view.

Preferably, one or each motor is arranged on the same axis as the geared rotary actuator in a spanwise direction.

There is also provided an aircraft comprising wing assembly according to the invention.

The invention allows for a GRA to be integrated into the lever architecture. The stroke of the GRA may be maximized using the preferred configurations, thereby increasing efficiency. This may be achieved due to a reduction of the required forces by increasing travel, thus reducing actuation momentum. As a result gear sizes within the GRA and the overall size of the GRA may be reduced. Consequently, weight and space efficiency are improved.

Embodiments of the invention are described in more detail with reference to the accompanying schematic drawings:.

Referring to <FIG>, an embodiment of an aircraft <NUM> is depicted. In a known manner, the aircraft <NUM> comprises a fuselage <NUM>, a vertical tail plane <NUM> and a horizontal tail plane <NUM>. Furthermore, the aircraft <NUM> comprises a wing assembly <NUM>, which comprises at least one high-lift device <NUM>, such as a slat <NUM>.

Referring now to <FIG>, an actuator arrangement <NUM> is configured to move the high-lift device <NUM> between a fully retracted position (<FIG>) and a fully extended position (<FIG>).

As depicted more closely in <FIG>, the high-lift device <NUM> is movably attached to a fixed leading edge member <NUM> (<FIG>) using a plurality of rails <NUM>, which are supported by roller bearings <NUM>. The rails <NUM> are attached to the high-lift device <NUM> via a lever assembly <NUM>.

In the present embodiment, the actuator arrangement <NUM> comprises two fixed leading edge levers <NUM>. The fixed leading edge lever <NUM> is mechanically coupled to the fixed leading edge member <NUM>.

Furthermore, the actuator arrangement <NUM> comprises a high-lift device lever <NUM>. The high-lift device lever <NUM> is coupled to the high-lift device <NUM>.

Furthermore, the actuator arrangement <NUM> comprises an actuator assembly <NUM>. The actuator assembly <NUM> is configured for driving the fixed leading edge lever <NUM> and the high-lift device lever <NUM> relative to each other, so as to extend and retract the high-lift device <NUM>.

The actuator assembly <NUM> comprises at least one actuator <NUM>. The actuator <NUM> is preferably a geared rotary actuator <NUM>.

The fixed leading edge member <NUM> comprises in manner known per se an outer skin <NUM> and a plurality of ribs <NUM>, which support the outer skin <NUM>. Adjacent ribs <NUM> and the outer skin <NUM> define an inner cavity <NUM> of the fixed leading edge member <NUM>.

Furthermore, the outer skin <NUM> comprises so-called D-nose cut-outs <NUM>, which allow extending and retracting the high-lift device <NUM> via the actuator arrangement <NUM> and the rails <NUM>.

In this embodiment, the actuator <NUM> is arranged predominately inside the inner cavity <NUM>, when in the fully retracted position (<FIG>). Furthermore, the actuator <NUM> is arranged predominately in an upper half of the inner cavity <NUM>, when in the fully retracted position.

In order to extend the high-lift device <NUM> the actuator arrangement <NUM> is operated. In doing so, the actuator <NUM> moves the fixed leading edge lever <NUM> relative to the high-lift device lever <NUM>.

As indicated in <FIG> and <FIG>, the fixed leading edge lever <NUM> and the high-lift device lever <NUM> stretch in the forward aft direction. In other words the angle between the fixed leading edge lever <NUM> and the high-lift device lever <NUM> is acute at the beginning and increases to be more than <NUM> degrees in the extended position (<FIG>). During the movement of the high-lift device <NUM>, the actuator <NUM> itself follows the movement along a circular arc section <NUM> until the actuator <NUM> is arranged entirely outside the inner cavity <NUM>, when in the fully extended position. Thus, the actuator <NUM> rotates about a rotational axis <NUM>. The rotational axis <NUM> is defined by the mounting point of the fixed leading edge lever <NUM>.

It should be noted that in the following further embodiments are only described in so far as they differ from the embodiment described above.

Referring to <FIG> and <FIG> the actuator arrangement <NUM> comprises a plurality of actuators <NUM>. Each actuator <NUM> has an input shaft <NUM> and an output shaft <NUM>.

Furthermore, the actuator arrangement <NUM> comprises a drive unit <NUM>. The drive unit <NUM> may be hydraulic or electric in nature.

The actuator arrangement <NUM> comprises a drive train formed by a plurality of straight drive shafts <NUM>, which are aligned substantially along the spanwise direction.

The drive unit <NUM> may be fixed in place and be connected to a first actuator <NUM> using an initial drive shaft <NUM> and universal joints <NUM>. Splines <NUM> may be used to transfer the torque.

Furthermore, the actuator assembly <NUM> comprises a second actuator <NUM> which is associated with the same high-lift device <NUM> as the first actuator <NUM>. The first actuator <NUM> and the second actuator <NUM> thereby form an actuator group <NUM>, which is associated with the same high-lift device <NUM>.

In this embodiment a connecting drive shaft <NUM> is mechanically coupled to the output shaft <NUM> of the first actuator <NUM> and to the input shaft <NUM> of the second actuator <NUM>.

In the case of a plurality of high-lift devices <NUM>, the output shaft <NUM> of the second actuator <NUM> is connected to a further actuator group <NUM> via a further drive shaft <NUM>.

As can be seen from <FIG>, this pattern is repeated until all high-lift devices <NUM> and their respective actuator group <NUM> are mechanically connected to the drive unit <NUM>.

As can be seen from <FIG>, the actuator <NUM> is arranged in its entirety within the inner cavity <NUM>, when in the fully retracted position, whereas the actuator <NUM> predominately protrudes outside the inner cavity <NUM> at the bottom in the fully extended position. The actuator <NUM> thus extends through one of the D-nose cut-outs <NUM>.

Referring now to <FIG> and <FIG>, the drive unit <NUM> comprises an electric motor <NUM>. As can be seen from <FIG> in particular, each electric motor <NUM> is arranged on the axis defined by the actuator <NUM>. Here, each actuator <NUM> has its own electric motor <NUM>.

As illustrated in <FIG>, the movement of the actuator or the actuator arrangement <NUM> is substantially the same as the movement in the previous embodiment.

Referring to <FIG>, a variant of the previous actuator arrangement <NUM> (<FIG>) is depicted. In this variant, an actuator group <NUM> are driven by a single electric motor <NUM>, which is connected to the respective actuators <NUM> using a drive shaft <NUM>.

Referring now to <FIG>, again each actuator <NUM> is driven by the drive unit <NUM> individually. As can be seen from <FIG>, in the fully retracted position, the actuator <NUM> is arranged in its entirety within the inner cavity <NUM>, as well as the drive unit <NUM>.

In particular, the actuator <NUM> is arranged in an upper half of the inner cavity <NUM>, whereas the drive unit <NUM> is arranged in a lower half of the inner cavity <NUM>, when in the fully retracted position.

In the fully extended position, the actuator <NUM> is predominately protruding outside of the fixed leading edge member <NUM>, whereas the drive unit <NUM> is still predominately accommodated within the inner cavity <NUM>.

Similarly, in the variant depicted in <FIG>, both the actuator <NUM> and the drive unit <NUM> are arranged in an upper half of the inner cavity <NUM> in the fully retracted position, whereas in the fully extended position, the actuator <NUM> protrudes outside the inner cavity <NUM> and the drive unit <NUM> is entirely accommodated within the inner cavity <NUM>.

With the described configurations of the actuator arrangement <NUM> the actuators <NUM>, such as geared rotary actuators <NUM>, can be integrated more easily into the small space provided by fixed leading edge member <NUM> and the high-lift device <NUM>.

In particular, the stroke of the actuator <NUM> may be maximized which allows an increase in efficiency due to a reduction of required forces for moving the high-lift device <NUM>. Due to the lower requirements the overall size of actuators <NUM> may be reduced so that weight and space efficiency are improved. Furthermore, the size of the D-nose cut-out <NUM> may be reduced using a preferred actuator arrangement <NUM>.

Claim 1:
A wing assembly (<NUM>) for an aircraft (<NUM>), the wing assembly (<NUM>) comprising a fixed leading edge member (<NUM>), a high-lift device (<NUM>) movably attached to the fixed leading edge member (<NUM>), and an actuator arrangement (<NUM>), the actuator arrangement (<NUM>) comprising:
- a fixed leading edge lever (<NUM>) attached to the fixed leading edge member (<NUM>) at a mounting point (<NUM>),
- a high-lift device lever (<NUM>) attached to the high-lift device (<NUM>), and
- an actuator assembly (<NUM>) that is configured for driving the fixed leading edge lever (<NUM>) and the high-lift device lever (<NUM>) relative to each other,
so as to allow movement of the high-lift device (<NUM>) between a fully retracted position and a fully extended position, wherein the fixed leading edge member (<NUM>) has an inner cavity (<NUM>) that is defined at least in part by an outer skin (<NUM>) and a rib (<NUM>), wherein the actuator arrangement (<NUM>) is configured for extending and retracting the high-lift device (<NUM>), the actuator assembly (<NUM>) including at least one geared rotary actuator (<NUM>), wherein the actuator assembly (<NUM>) is configured such that the geared rotary actuator (<NUM>) is movable during extending and retracting of the high-lift device (<NUM>) between a fully retracted position, in which the geared rotary actuator (<NUM>) is predominantly accommodated within the inner cavity (<NUM>), and a fully extended position, in which the geared rotary actuator (<NUM>) is predominantly positioned outside the inner cavity (<NUM>), wherein the geared rotary actuator (<NUM>) is rotatable about a rotational axis that is defined by the mounting point (<NUM>) of the fixed leading edge lever (<NUM>).