WO2009086804A1

WO2009086804A1 - Airplane landing gear

Info

Publication number: WO2009086804A1
Application number: PCT/DE2008/002139
Authority: WO
Inventors: Horst Duschek
Original assignee: Eads Deutschland Gmbh
Priority date: 2008-01-07
Filing date: 2008-12-19
Publication date: 2009-07-16
Also published as: DE102008003307A1

Abstract

The motor (5) for driving the wheels (2) of an airplane landing gear, particularly nose landing gear, is disposed in the base (7) of the landing gear strut (1) or is installed as a wheel hub motor in the wheel hub or rim (3). The motor is preferably configured as a hydraulic motor or electric motor and is supplied with energy via the landing gear strut. A heavy and complex transmission between the motor (5) and the wheel (2) can be eliminated.

Description

aircraft landing gear

The invention relates to a driven chassis, in particular nose landing gear, for an aircraft and an aircraft, in particular aircraft, with such a chassis.

Wing aircraft need so-called taxiing - as the driving on the ground before take-off procedure and after landing is called - a drive that has previously been ensured by the thrust of conventional engines, so by propellers or jet engines or turbines. However, this consumes very expensive fuel and leads to undesirable and unnecessarily high exhaust and noise emissions on the ground. In addition, for the purpose of depositing from a terminal of an airport by means of special towing vehicles (so-called "tugs"), which usually engage the nose gear of the aircraft, such aircraft have to be pushed backwards into an initial position, from which they then pass through the aircraft This requires on the one hand the availability of a towing vehicle and on the other hand the use of a tug service, which is chargeable at airports and quite expensive, in particular also because aircraft tractors are manufactured only in small numbers special vehicles and therefore correspondingly expensive ,

In order to address this problem, proposals have been made early on, in particular to drive the nose gear by a separate, the nose gear superior drive. In the US 3,977,631 from 1976, a motor is proposed, wherein the torque of the output shaft is transmitted via a complex planetary gear on a wheel of a two-wheel nose landing gear. Each nosewheel wheel is equipped with an engine and transmission. The transmission can be disengaged so as not to obstruct the high speeds of rotation and acceleration when landing. However, instead of providing a separate coupling for decoupling, the Brake disc assembly modified so that it can be used as a controllable clutch for coupling the wheel with the planetary gear. Overall, this solution is very complex, heavyweight and bulky. This leads to a considerable increase in the take-off weight of the aircraft and thus to an undesirable reduction of the payload and to an increase in fuel consumption and fuel costs. The large volume is reflected in increased drag with the landing gear extended, which is also detrimental to fuel economy.

A similar approach is followed in WO 95/29094. The planetary gear is here replaced by a bevel gear, which is housed in the foot of the leg and there drives two waves at the same time, on each of which a wheel is rotatably mounted. To avoid a collision with the brake assembly, the nose gear is not equipped with brakes. In the event that both wheels are driven, the transmission is designed as a differential gear. Both wheels have a freewheel, so that the transmission does not hinder the acceleration of the wheels when landing, but when cornering and especially when turning the nose gear in the state one wheel is braked or blocked, so that the other, free-wheel around it can move. In the event that only one wheel is driven, can be dispensed with the differential. In all cases, the recorded in the foot mechanical transmission is connected to a motor arranged in the wind through a drive shaft.

Recently, the topic of driving the wheels of the nose landing gear by means of a separate motor is gaining in importance again. In Aviation Week & Space Technology, August 8, 2005, page 40, under the title "Portable Tug", a propulsion system is proposed in which the wheels of the nose landing gear are driven by a superior "portable" drive separate from the nose gear, which is its torque via a belt to a wheel-mounted pulley transfers. The experimental setup described there is heavy and probably too bulky to be retracted with the chassis in the landing gear chamber become. This drive, which effectively represents a miniature tractor, is therefore obviously only used in ground operation and must be specially mounted for this purpose on the aircraft and removed before take-off or after docking again. This is very expensive. The "portable tug" is not suitable to remain on the aircraft and be transported with this even in flight.

Object of the present invention is to provide a drivable suspension, especially nose landing gear, an aircraft, which combines the requirements of low weight, low footprint and low impact on the aerodynamics as possible in itself. Furthermore, an aircraft is to be provided with such a chassis.

This object is achieved according to a first aspect by an inventive chassis with the features of claim 1.

Preferred embodiments of the landing gear according to the invention are the subject of the dependent claims 2 to 15, which find their support in the following description and the drawings.

An inventive landing gear for an aircraft, in particular a nose landing gear, comprises a leg with a foot on which at least one wheel is rotatably mounted, and further comprises a motor coupled to the wheel for driving the wheel. According to the invention, the motor is housed in or at the foot of the leg and drives a shaft through which the wheel is directly or indirectly coupled to the motor, or it is - alternatively - the wheel rotatably mounted on a rotationally fixed at the foot of the leg axis fixed and the engine designed as a hub motor. A part of the wheel hub motor is supported in a rotationally fixed manner on the non-rotatable axle or another non-rotating part of the chassis foot, while the other, relative to rotatable part of the wheel hub motor directly or indirectly engages the rotatable wheel. As a wheel hub motor, for example, the engine can be accommodated within the wheel hub or integrated into a rim of the wheel. The fixed part of the wheel hub motor may be partially or completely housed in the chassis foot. In all these cases, he does not disturb the aerodynamics or at most only insignificantly. In the event that the motor used is housed partially or completely in the foot of the leg, it preferably sits in an aerodynamically designed housing. The retraction of the chassis in the landing gear chamber is not hindered by the construction according to the invention, since the size of the landing gear chamber essentially depends on the size of the wheels and space in the region of the chassis foot and the wheel hub are thus available.

For the purposes of the present invention, an engine is understood to be an engine for driving the wheel, in which a first, non-mechanical energy is converted into a second, mechanical energy. For the purposes of the present invention, a hydraulic motor or an electric motor is preferably used as the motor, since such motors can produce high powers and torques in a compact and lightweight construction. This offers the particular advantage that in many cases no transmission between the engine and the wheel is required, which can be additionally saved weight. As hydraulic motors, for example radial piston motors or gerotor motors can be used, since they are small and compact and have a very high torque. As electric motors in particular capacitor motors and external rotor motors, which can also provide a high torque, are particularly suitable. As a wheel hub motor is particularly suitable both a hydraulic and an electric wheel hub motor, since these motors usually do not require a separate gear.

The wheel hub motor is a motor that does not drive the axle on which the wheel hub sits but drives the wheel itself in the area of the wheel hub. The wheel hub is the central rotating part of the wheel. The wheel hub motor can lie radially inside the wheel hub and drive the wheel hub from the inside or even lie next to the wheel hub and drive the wheel hub, for example on the rim from the outside.

If two or more wheels of the chassis are each coupled to a motor, in particular wheel hub motor, a differential effect can be achieved in which during cornering, the respective outer wheel turns faster than the inner curve wheel, realize control and / or control technology , As a result, both the tire wear and control forces during cornering can be reduced. Since nose landing gear usually represent a single steering axle, and caused by cornering tire wear on the wheels of the nose gear due to the very small track width is already comparatively low, however, can usually be dispensed with a differential, so that the overall construction is lightweight. Advantageously, the separate driving of the motors to achieve a differential effect but especially if only, or in addition, one or more wheels of the main landing gear are driven. In the case of main landing gears, there is usually at least one leg each under one wing. If the chassis according to the invention is now designed as a main landing gear, active control can be achieved by controlled driving of the respective main landing gear sides. Also, then cornering with extremely tight curves or, in reverse drive, even turning the aircraft "on the spot" possible.

Installing the motor in the foot of the leg or directly into the wheel hub not only offers the advantage of better protection of the entire drive unit. It can also be better maintained, as it can be assembled or disassembled with the wheels when installed in the foot of the leg, or accessible over the rims when installed in the wheel hub or rim. The supply line for the power supply of the engine, for example hydraulic hoses or electrical lines, can be laid in a simple manner in or on the leg. This results in an aerodynamically favorable arrangement and requires no complex attachments or additional components.

Preferably, the drive of the wheel is reversible, that is, the direction of rotation of the wheel is reversible. This is important for the departure of the terminal against the direction of travel. For switching from the forward to the reverse drive, for example, a switching clutch can be provided in the drive. However, such couplings are usually relatively large, heavy and expensive. It is cheaper there, if the engine itself is reversible. This is e.g. in the case of a hydraulic motor by a simple switching valve or the like and in the case of a (DC) electric motor by a switch for reversing the electric current direction feasible.

The drive of the wheel or the wheel itself may have a freewheel that should be lockable in the case of a reversible drive to allow the reverse drive. The freewheel prevents parts of the drive unit from being unnecessarily rotated by the wheels when starting or landing. Instead of a freewheel also a coupling device for coupling and decoupling of the wheel can be provided by the engine. In the decoupled state, the wheel is then free-running in both directions.

The chassis according to the invention can be used in particular for highly loaded, brakable chassis large aircraft. The installation of the drive motor at the described positions does not affect the arrangement of the brakes or only slightly, so that in this respect no major modifications to the chassis must be made.

Conventional aircraft can be relatively easily equipped or retrofitted with a nose landing gear according to the invention. The power supply of the motor is preferably independent of the Main engines of the aircraft, in particular via the so-called APU ("Auxiliary Power Unit") For taxiing or dropping from the terminal, the main engines must therefore not be operated, whereby fuel is saved to a considerable extent and exhaust emissions are reduced.

The object underlying the invention is achieved according to a second aspect by an inventive aircraft with the features of claim 16.

Preferred embodiments of the aircraft according to the invention are the subject of the dependent claims 17 to 21, which find their support in the following description and the drawings.

An aircraft according to the invention, which is equipped with a driven chassis according to the invention, can operate with the help of the same completely autonomous taxiing or docking / dropping and is not dependent on tractors and a corresponding airport infrastructure in the last-mentioned procedures. It acts as his own tug. For taxiing, the thrust of the main engines is no longer required, so that fuel is saved and exhaust and noise emissions are reduced. The integrated drive through the chassis has compared to conventional constructions a low installation volume and a comparatively low weight. The empty weight of the aircraft, which is equipped with this drive, therefore, increases only slightly. This results in no significant increase in fuel consumption in flight operations. The powered landing gear can therefore be designed as a system flying with the aircraft. The drive can be installed directly in the existing wheel construction or in the foot of the leg. The drive can be pivoted with the chassis in the landing gear shaft and thus does not contribute in flight operation to an increase in air resistance. The drive is also structurally and aerodynamically integrated into the chassis in the extended state of the chassis. A powered aircraft equipped with a powered landing gear according to the invention expediently has a drive control device, which is coupled to the engine and adapted to control the drive of the relevant wheel from the cockpit of the aircraft. The drive control device can communicate with a floor guidance system or floor guidance system and refer to it from the control signals for the drive and operation of the engine of the chassis according to the invention. In this way, even a completely automatic docking / depositing and taxiing of an aircraft can be realized. However, as with most automatic flight guidance systems, pilot control commands should be prioritized.

Furthermore, an aircraft according to the invention preferably has an image acquisition system looking at least at the rear of the aircraft and a functionally connected image display device in the cockpit, via which the pilot or another member of the cockpit crew is informed about events taking place behind the aircraft during reverse travel , As a result, no ground personnel is required to control the space behind the airfield on clear field when resetting the aircraft. This will be done by the pilot or other members of the cockpit crew instead. However, the image capture system can also be designed to look to the bow of the aircraft, or it can be designed for multiple viewing directions, in particular to be mobile. A forward-looking imaging system can also be helpful when docking or driving on the so-called taxiway.

Instead of the image capture device, or in addition thereto, an obstacle detection system and / or obstacle warning system orientable at least to the rear of the aircraft may be provided in the aircraft, which is functionally connected to the image display device or to a separate warning device in the cockpit and alert the pilot to obstacles in the rear area of the aircraft makes, especially when resetting or Reversing the aircraft is of importance. However, the obstacle detection system may also be configured to detect obstacles in front of and / or laterally of the aircraft. The obstacle detection system can also be designed for all-around detection of obstacles. Thus, the safety when maneuvering the aircraft on the ground can be significantly increased. The obstacle detection system can be completely autonomous or even obtain information from ground-based components and / or exchange data. In particular, the obstacle detection system can communicate with the already mentioned floor guidance system or floor guidance system.

The invention will be explained by way of example with reference to the accompanying drawings. Show:

Fig. 1 is a schematic, partially sectioned rear view of a first

Embodiment of a nose landing gear according to the invention with wheel hub motor,

Fig. 2 is a schematic, partially sectioned rear view of a second embodiment of an inventive

Nose landing gear with motor in the foot of the leg, and

Fig. 3 shows an aircraft with a chassis according to the invention.

Fig. 1 shows a first embodiment of a nose gear according to the invention with two suspended on a leg 1 wheels 2, each having a mounted on a rim 3 tires 4 in a conventional manner. Of course, the chassis can also have only one wheel or more than just two wheels. The brakes of this chassis are not shown in FIG. Each wheel 2 is driven by means of a wheel hub motor 5, which is integrated here in the rim 3 and may for example be a hydraulic motor or electric motor. The power supply for the hub motor 5 is done via lines 6, which are mounted by the leg 1, the foot 7 of the leg 1 and the rigid axle 8, on which the wheel 2 is mounted rotatably mounted, to the wheel hub motors 5. The power source for the motor 5 sits in the fuselage or in its attachments (eg wings, tail units, pylons, etc.). Particularly in the case of an electric motor, the power supply preferably takes place independently of the main engines of the aircraft, for example via the on-board APU ("auxiliary power unit") .If it is a hydraulic engine, it can be connected to an already existing general hydraulic system of the aircraft, whose hydraulic pump can in turn be powered by the on-board APU.

Instead of integrating the wheel hub motor 5 in the rim, it may also be located radially inside the wheel hub. For example, the axis on which the wheel hub runs, be designed as a stator and the associated rotor be integrated into the wheel hub.

About the two lines 6, the wheel hub motors 5 of the two wheels 2 can be controlled separately, so that if necessary, a differential effect is technically feasible. On a mechanical differential gear can be omitted. In any case, the use of a separate, large and heavy mechanical transmission can be dispensed with, since hydraulic motors and electric motors can provide very high outputs and torques despite a small overall volume. Optionally, in addition to the nose landing gear and the main landing gear can be equipped with appropriate drives.

Fig. 2 shows a second embodiment of a nose landing gear according to the invention. In this case, a common motor 5 is housed in the foot 7 of the leg 1 for the two wheels 2 and drives a shaft 9, via which the respective wheel 2 is coupled to the motor 5. In the exemplary embodiment, the motor 5 is an electric motor, which is supplied via the line 6, wherein the stator of the electric motor stationary in the foot 7 of the Leg 1 sits and the rotor is fixed to the rotatable shaft 9. A transmission gear is not available in this example. The respective wheel 2 is seated on the primary output shaft 9 of the engine 5. Basically, however, a reduction gear can be interposed. This can be integrated, for example, in the engine or the foot 7. Only schematically indicated in FIG. 2, the possibility of integrating a brake 10 in the system. The brake 10 is controlled separately. It can be rotatably coupled in a conventional manner with the foot 7 and be hydraulically pressed against brake discs of the wheel 2.

Fig. 3 shows schematically an inventive aircraft, which is equipped with a driven chassis F according to the invention. The engine of the landing gear is coupled to an APU ("Auxiliary Power Unit") of the aircraft or other suitable source of energy through which the power necessary to power the engine is available is arranged to control from a cockpit of the aircraft from the drive and / or the direction control of the wheel or the wheels 2 of the chassis F. The drive control device is also connected to the APU ("Auxiliary Power Unit") and adapted to the supply of energy from the APU to the engine. If the motor is an electric motor, it is expediently connected to the electrical vehicle electrical system that can be supplied by the APU and / or another energy source or forms a part (possibly also autonomous) thereof. If the engine is a hydraulic motor, it is expediently connected to the general hydraulic system of the aircraft, which can be supplied by the APU and / or another energy source, and forms a (possibly also autonomous) part thereof.

As further outlined in FIG. 3, the aircraft according to the invention also has an image capture device 11, which is provided with a non-illustrated

Image display device is connected in the cockpit and the direction of view points in particular to the rear of the aircraft. That way, the pilot can When resetting or maneuvering the aircraft, check the space behind the aircraft for cleared area. The mounting location of the image capture device 11 is shown purely schematically in the drawing. The image capture device 11 may, in particular, comprise a plurality of sensors which are mounted at different locations on the aircraft and, for example, detect different regions of the surroundings of the aircraft. The image capture device 11 may also or additionally be configured as a hindrance detection device which automatically detects obstacles below, behind, beside and in front of the aircraft. The obstacle detection device may be operatively connected to the image display device or a separate warning device in the cockpit to actively alert the pilot to obstacles. Depending on the current situation, the pilot can then control the drive of the wheels 2 accordingly via the drive control device.

The invention is not limited to the above embodiments. Within the scope of protection, the landing gear according to the invention and the aircraft according to the invention may also assume other than the concretely described embodiments. Here, features of the described embodiments may also be combined. A single wheel can also be powered by multiple motors. The rim of a wheel can be adapted to the motor or hub motor used and for this purpose be shaped accordingly. The drive control device may include an interface for connecting an external control device so that ground personnel, for example, is able to control the aircraft for docking or dropping off a terminal by means of the powered landing gear.

Reference signs in the claims, the description and the drawings are only for the better understanding of the invention and are not intended to limit the scope. LIST OF REFERENCE NUMBERS

1 leg

2 wheel

3 rim

4 tires

5 engine / wheel hub motor

6 lines

7 feet from 1

8 Rigid axis

9 wave

10 brake

11 image capture device

F suspension

Claims

claims

1. Landing gear for an aircraft, in particular nose landing gear, comprising a leg (1) with a foot (7) on which at least one wheel (2) is mounted rotatably mounted, and one with the wheel (2) coupled to the engine

(5) for driving the wheel (2), characterized in that the motor (5) is housed in the foot (7) of the leg (1) and drives a shaft (9) via which the wheel (2) engages the motor (5) is coupled, or - the wheel (2) mounted on a at the foot (7) of the leg (1) rotatably fixed axis (8) and the motor (5) is designed as a wheel hub motor.

2. Suspension according to claim 1, characterized in that the motor (5) is a hydraulic motor.

3. Suspension according to claim 1, characterized in that the motor (5) is an electric motor.

4. Suspension according to claim 3, characterized in that the electric motor is a capacitor motor.

5. Suspension according to claim 3, characterized in that the electric motor is an external rotor motor.

6. Suspension according to claim 3, characterized in that the

Electric motor is an electric wheel hub motor.

7. Suspension according to one of claims 1 to 6, characterized in that the wheel hub motor is housed within the wheel hub.

8. Suspension according to one of claims 1 to 6, characterized in that the wheel hub motor in a rim (3) of the wheel (2) is integrated.

9. Suspension according to one of claims 1 to 5, characterized in that the wheel (2) on a shaft (9) sits, which is a primary output shaft of the motor (5).

10. Suspension according to one of claims 1 to 9, characterized by a connecting line (6) for supplying the motor (5) with energy via the leg (1).

11. Suspension according to one of claims 1 to 10, characterized in that the drive of the wheel (2) is reversible.

12. Suspension according to claim 11, characterized in that the motor (5) is reversible.

13. Suspension according to one of claims 1 to 12, characterized in that at least two wheels (2) of the same leg (1) or different legs (1) each having at least one such

Motor (5) are coupled, wherein the motors (5) are separately controllable.

14. Suspension according to one of claims 1 to 13, characterized in that the drive of the wheel (2) or the wheel (2) itself has a freewheel.

15. Suspension according to one of claims 1 to 13, characterized by a coupling for coupling or decoupling of the wheel (2) from the motor (5).

16. Aircraft comprising a landing gear according to one of claims 1 to 15 and coupled to the engine (5) of the chassis drive control device which is adapted to control from a cockpit of the aircraft from the drive of the wheel (2).

17. Aircraft according to claim 16, characterized by an at least the rear of the aircraft looking imaging system (11) and a functionally connected image display device in the cockpit of the aircraft.

18. An aircraft according to claim 16 or 17, characterized by an at least to the rear of the aircraft orientable Hindemisdetektionseinrichtung (11) and a functionally connected warning device in the cockpit.

19. An aircraft according to any one of claims 16 to 18, characterized in that the motor (5) with an APU ("Auxiliary Power Unit") of the aircraft is connected, via which the necessary energy for driving the motor (5) is available.

20. An aircraft according to any one of claims 16 to 19, characterized in that the drive control means coupled to the APU ("Auxiliary Power Unit") and adapted to control the supply of energy from the APU to the engine (5).

21. Aircraft according to one of claims 16 to 20, characterized in that the engine (5) is connectable to a general hydraulic system of the aircraft, and via this hydraulic system, the necessary energy for driving the motor (5) is available.