Propulsion system for an aircraft

Abstract

Propulsion system for an aircraft, in particular for an airplane, comprising at least one wheel of the aircraft, wherein the wheel has at least one axle, an electric motor as a drive unit, and at least one shaft running inside the wheel axle, wherein the shaft is connected to the wheel on the output side and to the drive unit on the input side, and the drive unit is located below a shock absorber, characterized by the fact that a coupling and / or a gearbox is / are arranged between the shaft and the drive unit, wherein the clutch and / or the transmission are located in an area next to the wheel axle, so that the clutch and / or the transmission is / are arranged perpendicular to the wheel axle.

Description

[0001] The present invention relates to a drive system for an aircraft, in particular for an airplane, comprising at least one wheel of the aircraft, wherein the wheel has at least one wheel axle.

[0002] It is known from the state of the art that aircraft are powered by their engines when taxiing to and from the runway. However, at this operating point, aircraft engines are inefficient, resulting in a comparatively poor energy balance in terms of fuel consumption. Furthermore, it is important that the aircraft engine and its associated components take up as little space as possible when retracted.

[0003] Document DE 20 50 011 A discloses a conventional drive unit for an aircraft landing gear. Furthermore, DE 882 190 B discloses a drive for overhung aircraft landing gear.

[0004] The present invention is therefore based on the object of developing a propulsion system for an aircraft such that taxiing to and from the runway can be carried out more energy-efficiently than with the known procedure. At the same time, the object is to design the propulsion system in such a way that it requires as little installation space as possible.

[0005] These objects are achieved by a drive system having the features of claim 1.

[0006] According to this, the drive system comprises at least one drive unit and at least one shaft extending inside the wheel axle, wherein the shaft is connected directly or indirectly to the wheel on the output side and directly or indirectly to the drive unit on the drive side. Furthermore, the drive unit and preferably also a transmission are arranged below a shock absorber.

[0007] Typically, the landing gear of an aircraft is designed to be retractable and extendable. The wheel is articulated to the main body of the aircraft via a strut unit. With the help of this articulated connection, the wheel can be moved into a position spaced from the main body of the aircraft. In this position, the drive unit is located in an area that is closer to the connection between the strut unit and the wheel than to the connection between the strut unit and the main body of the aircraft. The drive motor is therefore extended together with the wheel when the landing gear is extended. Preferably, the drive motor is arranged on the strut unit, in an area that is closer to the connection to the wheel than to the articulated connection to the main body of the aircraft.

[0008] As a result, the drive unit is located beneath a landing gear shock absorber when the landing gear is extended. The strut unit, at the end of which the wheel(s) are located at a distance from the main body of the aircraft, typically consists of a telescopic tube arrangement that can be pushed into one another. In this case, the drive unit and preferably also the transmission are located beneath a damping element or beneath all shock absorbers.

[0009] The strut unit may also include, among other things, a thrust tube. The drive unit may be arranged in the thrust tube.

[0010] A gearbox and / or a clutch can be provided between the drive unit and the wheel driven by it.

[0011] The arrangement of the propulsion unit requires very little storage space within the aircraft's main body, allowing for effective use of the available space within the aircraft.

[0012] The drive unit is preferably designed as an electric motor.

[0013] The present invention makes it possible to move the aircraft to and from the runway solely by the drive unit of the propulsion system and not to use the engines or at most to support the movement.

[0014] The arrangement of the shaft that drives the wheel(s) inside the wheel axle enables a particularly space-saving, weight-saving and compact design.

[0015] Compared to a conceivable design of a wheel drive with a spur gear mounted on the wheel rim, the embodiment according to the invention offers weight advantages as well as the advantage that deformation of the wheel axle has no adverse effects on safety and efficiency. In the aforementioned design with a spur gear, however, deformation of the wheel axle has the consequence of influencing the backlash between the spur gear and the rim, which may result in disadvantages with regard to the safety and efficiency of the wheel drive.

[0016] It is conceivable that the drive system has at least one fastening part that is connected to the wheel in a rotationally fixed manner and that is connected to the shaft in a form-fitting or other rotationally fixed manner. This fastening part, located on the output side, thus establishes the connection between the shaft and the wheel. The fastening part can have a toothing through which the fastening part is connected to the shaft in a form-fitting manner, so that a rotational movement of the shaft leads to a rotational movement of the fastening part.

[0017] The invention also encompasses the fact that the fastening part forms an integral part of the shaft.

[0018] The fastening part can be a bell-shaped component that surrounds the end of the shaft and / or the end of the wheel axle.

[0019] The wheel can be screwed to the fastening part.

[0020] In a further embodiment of the invention, the shaft comprises at least one gearwheel that is rotationally fixed relative to the shaft and driven directly or indirectly by the drive unit. Preferably, the gearwheel is connected to the shaft via a positive connection. It is also possible, and encompassed by the invention, for the gearwheel to form an integral component of the shaft.

[0021] Preferably, there is at least one clutch and / or gearbox between the shaft and the drive unit.

[0022] The axle may have at least one aperture through which means extend through which the shaft is driven by the drive unit. These means may, for example, be the aforementioned gear and / or the transmission and / or the clutch and / or the drive unit, or parts of the aforementioned elements.

[0023] The opening is preferably located in the outer surface of the axle and is preferably spaced from the ends of the axle. It is preferably located in the center of the axle or in a central region of the axle.

[0024] In the case of at least two wheels running on the axle, the opening is preferably located between the wheels or between two of the wheels.

[0025] It is also conceivable for the shaft to be driven by the drive unit at the end of the shaft or axle, so that there is no opening in the axle through which the means for driving the shaft by the drive unit extend. This embodiment is preferably used when only one wheel is arranged on the axle.

[0026] A further optional feature of the present invention is that a torque fuse is arranged in a drive train from the drive unit to the wheel, which interrupts power transmission via the drive train when a torque threshold value is exceeded, wherein the torque fuse preferably breaks when the torque threshold value is exceeded.

[0027] The torque limiter is an overload protection device and ensures that only permissible torques act on the drive train between the drive unit and the wheel. The torque limiter is preferably designed as a predetermined breaking point on a shaft.

[0028] The present invention further relates to a landing gear of an aircraft, in particular of an airplane, with at least one propulsion system according to one of claims 1 to 8.

[0029] The present invention further relates to an aircraft, in particular an airplane, with at least one propulsion system according to one of claims 1 to 8 or with at least one landing gear according to the invention.

[0030] Further details and advantages of the invention are explained in more detail with reference to an embodiment illustrated in the drawing. They show: Fig. 1: a perspective view of a landing gear of an aircraft with a propulsion system according to the invention, Fig. 2: a schematic view of a drive system according to the invention, Fig. 3: a sectional view of the drive system according to the invention, and Fig. 4: a schematic view of a drive system according to the invention according to a further embodiment.

[0031] Fig. Figure 1 shows the landing gear frame of an aircraft, designated by reference numeral 10. Its upper end portion is pivotably mounted on the aircraft structure.

[0032] In its lower end region, the chassis frame 10 has a wheel axle 12 on which a wheel 20 is rotatably located.

[0033] Reference numeral 30 denotes an electric motor that drives a shaft located in the axle 12 via a gear 35. The electric motor 30 is preferably connected to the gear 35 via a clutch. It can be seen that the electric motor 30 is arranged below a shock absorber of the landing gear frame 10. It is also clearly visible that the electric motor 30 is arranged closer to the connection to the wheel 20 than to the articulated connection to the main aircraft body.

[0034] How this Fig. As can be seen in Figure 2, the shaft 40 extends within the wheel axle 12. The electric motor 30, the gearbox 35, and the clutch are located in an area adjacent to, i.e., outside the wheel axle, but almost in close proximity to it. Typically, the running surface of the driven wheel 20 defines a cylindrical body whose central axis is the shaft 40, which also houses the drive motor.

[0035] In the embodiment according to Fig. 2, two wheels 20, 20' are arranged on the wheel axle 12, of which only wheel 20 is driven by the shaft 40, while wheel 20' is a non-driven wheel. In principle, it is also conceivable and encompassed by the invention that the shaft drives both wheels 20, 20'.

[0036] Reference numeral 50 designates the wheel connection, which is non-rotatably connected to the rim 60 of the wheel 20. A screw connection is conceivable.

[0037] The wheel connection can be designed as a bell 50, which is positively connected to the shaft 40 via a toothing.

[0038] How this Fig. As can be seen from Figure 2, the shaft 40 extends within the axle 12, i.e., in the cavity of the axle 12, and is supported there. The shaft 40 extends only in the section between the drive unit or gear 42 and the driven wheel 20, and not between the drive unit or gear 42 and the non-driven wheel 20'.

[0039] A gear 42 is attached to the shaft 40 by a positive connection, via which the shaft 40 is driven.

[0040] Through an opening 14 in the middle of the axle 12, the gear 42 is separated from the rest of the Fig. 2 not shown gear 35, which in turn is driven by the electric motor 30 and which may have a clutch.

[0041] For chassis with only one tire or with tires that extend only on one side of the gear 42 or the drive unit, it can also be provided that the drive of the shaft 40 occurs from the side, i.e., not only through a central section or opening in the wheel axle. An opening in the axle 12 is not necessary in this case.

[0042] Fig. Figure 3 shows a side sectional view of the drive system according to the invention. It shows the drive unit 30, which is connected to the transmission 35 via a clutch 50. The transmission 35 is operatively connected to the shaft 40. The drive unit 30 and the transmission 35 are arranged between the two wheels (not shown).

[0043] In Fig.Figure 4 shows a further embodiment of the invention. Here, the motor 35 is inserted into a torque tube 70. The torque tube 70 has openings through which ventilation, cables, and other sensors can be routed. Thus, the power supply line 31 of the motor 35 and the control line 32 of the motor 35 are routed through openings in the torque tube 70. Furthermore, an optional clutch 50 is shown, which separates the transmission from the T-gearbox 60. The T-gearbox 60 can also have a differential that maps the drive to the two wheel drive shafts 40. The drive unit 30 and the transmission 35 are arranged between the two wheels.

[0044] In addition, you can once again see the structure of the gearbox, which has already been described in detail.

[0045] The landing gear designed with the propulsion system according to the invention can be any landing gear of an aircraft, such as the nose gear or the main gear.

Claims

[1] Propulsion system for an aircraft, in particular for an airplane, comprising at least one wheel of the aircraft, wherein the wheel has at least one wheel axle, an electric motor as a drive unit, and at least one shaft running inside the wheel axle, wherein the shaft is connected to the wheel on the output side and to the drive unit on the input side, and the drive unit is arranged below a shock absorber, characterized by , that a clutch and / or a gearbox is / are arranged between the shaft and the drive unit, wherein the clutch and / or the gearbox are located in an area next to the wheel axle, so that the clutch and / or the gearbox is / are arranged offset perpendicularly to the wheel axle. [2] Drive system according to claim 1, characterized bythat at least one fastening part is provided which is connected to the wheel in a rotationally fixed manner and which is positively connected to the shaft. [3] Drive system according to claim 2, characterized by that the fastening part is a bell-shaped component that engages around the shaft end and / or the end of the wheel axle and / or that the fastening part is screwed to the wheel. [4] Drive system according to one of the preceding claims, characterized by that the shaft has at least one gearwheel which is rotationally fixed relative to the shaft and which is driven directly or indirectly by the drive unit, wherein it is preferably provided that the gearwheel is connected to the shaft via a positive connection. [5] Drive system according to one of the preceding claims, characterized bythat the axle has at least one opening through which a means extends by which the shaft is driven by the drive unit. [6] Drive system according to one of the preceding claims, characterized by that the drive of the shaft is effected by the drive unit at the end of the shaft or axle, so that there is no opening in the axle through which a means extends by which the shaft is driven by the drive unit. [7] Drive system according to one of the preceding claims, characterized by that a torque fuse is arranged in a drive train from the drive unit to the wheel, which interrupts power transmission via the drive train when a torque threshold value is exceeded, wherein the torque fuse preferably breaks when the torque threshold value is exceeded. [8] Chassis with at least one drive system according to one of claims 1 to 7. [9] Aircraft, in particular an airplane, with at least one landing gear according to claim 8 or with at least one propulsion system according to one of claims 1 to 7.

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