Running gear of an aircraft or land vehicle

Abstract

The invention relates to running gear of an aircraft or land vehicle, which is equipped with an axle, a wheel supported by the axle, and an electromechanical actuator having an output side which is connected, in terms of transmission, to an input side of a transmission assembly. The transmission assembly can be switched between at least two operating modes. In a first mode, the transmission assembly couples the electromechanical actuator to a brake assembly in order to actuate or release the brake assembly, so that the brake assembly can apply a braking torque to the wheel in response to actuation of the brake assembly. In a second mode, the transmission assembly couples the electromechanical actuator to the wheel in order to rotate the wheel. In a third mode, the transmission assembly couples the electromechanical actuator to a fan assembly which acts on the brake assembly and / or on the wheel, in order to actuate the fan assembly.

Description

[0001] Landing gear of an aircraft or land vehicle

[0002] Description

[0003] Introduction

[0004] This document describes the landing gear of an aircraft or land vehicle. Such a landing gear also includes a dynamic propulsion / deceleration and ventilation unit. Details of this are defined in the claims. The description also contains relevant information on the structure and function of the device, as well as on device variants.

[0005] background

[0006] Modern aircraft have wheel brakes, which are activated after aerodynamic aids have begun to exert their braking effect. These aerodynamic aids include retractable and extendable flaps on the sides of the wings. Extending the flaps counteracts the aircraft's lift and simultaneously increases its drag. Another aerodynamic aid is thrust reversal, caused by devices on the aircraft's engines that generate counterthrust when the aircraft lands, which also slows the aircraft down. When the wheels touch down on the runway, the initially stationary wheels are traditionally brought up to the speed of the aircraft, and then the braking torque is transferred via the wheels to the runway. This process causes significant tire wear. In addition, the high friction during braking causes the wheel brakes to become very hot.Before the aircraft is allowed to take off again, the wheel brakes must first be allowed to cool down safely, e.g. by means of an external fan directed from the outside onto the wheel brake in the parking position.

[0007] Commercial aircraft typically use hydraulic braking systems. These require hydraulic pressure generators and reservoirs dimensioned for landing and aborting the aircraft, which increase the aircraft's mass. Therefore, several concepts for electrically or electromechanically actuated braking systems are known.

[0008] Until now, aircraft tugs have generally been used to back up aircraft from the gate. They bring the aircraft into position so that they can taxi to the runway using their engines. Depending on the aircraft type, taxiing to the runway can consume up to 700 kilograms or more of kerosene. To reduce kerosene consumption and noise pollution during taxiing, electric motors were installed in the main landing gear of a commercial aircraft for trial purposes. These motors serve as the drive for taxiing on the ground. An aircraft tug is no longer necessary for backing up from the gate and taxiing to and from the runway. The electric motors are controlled from the cockpit. An auxiliary gas turbine (APU), which is also responsible for the rest of the on-board power supply, supplies the electric motors with power.

[0009] State of the art

[0010] US 2017 / 0267336 A1 (Safran Landing Systems) relates to an aircraft landing gear comprising an axle, a wheel supported by the axle, and a stack of brake discs arranged to exert a braking torque on the wheel in response to a pressure applied to the disc stack. At least one electromechanical actuator facing the disc stack serves to exert pressure on the disc stack. An actuator carrier supports the electromechanical actuator. The actuator carrier is integrated into the axle such that the axle and the actuator carrier form a single component.

[0011] CA 2 845 205 C (Messier-Bugatty-Dowty) relates to an electromechanical actuator for a vehicle brake comprising a first and a second part which are separable from one another, the first part comprising an electric motor and connecting means for connecting the actuator to an external control means, and the second part comprising a plunger which slides out of the first part of the housing and projects from the second part through a central opening. The first and second parts are coupled such that the motor cooperates with the plunger to cause movement of the plunger in response to an action of the motor, the second part comprising a second element made of two parts.

[0012] EP 2 666 717 A2 (Goodrich) relates to a system comprising an electric motor coupled to a first transmission, a first clutch for selectively engaging the first transmission with a drive gear, and a braking system, wherein in response to engagement with the drive gear, the electric motor drives an aircraft wheel, and wherein in response to engagement with a thrust element, the electric motor actuates the braking system to exert a force on a brake disc stack. The system further comprises an aircraft wheel, wherein the drive gear causes rotation of the aircraft wheel. Another system comprises an aircraft wheel having an engagement portion for interacting with a drive gear, wherein the aircraft wheel is coupled to an aircraft brake.The aircraft brake includes a braking system for selectively compressing a stack of brake discs, a rotating element, and a first clutch for selectively engaging the rotating element with either the drive gear or the braking system. A second clutch selectively couples the drive gear to the aircraft wheel. A portion of the clutch has a toothed portion. The rotating element of the clutch is driven by an electric motor. The braking system has a ball screw and a follower. The braking system has a second gear coupled to the ball screw. Either the drive gear or the second gear has a variable gear ratio. The first clutch has a neutral position in which the first gear is disengaged from the braking system and disengaged from the drive gear.

[0013] EP 3 453 613 A1 (Goodrich) relates to an aircraft with a landing gear having a wheel, a friction brake with a braking material coupled to the wheel, a regenerative brake with a reversible roll motor, a sensor for measuring a wheel parameter, a friction brake temperature, and memory for communicating with a controller. Instructions are stored in the memory that cause the controller to perform the following operations: receiving a command signal, the wheel parameter, and the friction brake temperature; calculating a braking material temperature based on the wheel parameter, the friction brake temperature, and the command signal; and generating an associated deceleration for the friction brake and the regenerative brake according to the calculated braking material temperature and the command signal.

[0014] EP 3 121 077 A1 (Goodrich) relates to a braking and rolling system comprising an electric motor having a first and a second output shaft, a clutch for selectively coupling the electric motor to at least one drive gear and a brake gear. The electric motor, in response to coupling with the drive gear, exclusively drives an aircraft wheel via the first output shaft, and in response to coupling with the brake gear via the second output shaft, exclusively drives a brake tensioning system to exert force on a brake disc stack. The drive gear is located on the opposite side of the electric motor as the brake gear. The electric motor, the drive gear, and the brake gear are concentrically aligned. The brake tensioning system and the brake gear have a ball screw and a tappet. The first output shaft and the second output shaft are concentrically arranged.The drive gear drives the rotation of the aircraft wheel. The drive gear or brake gear is a high-ratio gear of approximately 30:1 to approximately 110:1. The drive gear or brake gear comprises a planetary gear train. The system has an aircraft wheel with a connecting section for connecting to a drive gear. The aircraft wheel is coupled to an aircraft brake. The aircraft brake has a brake tensioning system for selectively coupling to a brake disc stack, and a clutch for selectively coupling an electric motor to the drive gear or brake gear. The electric motor has a central longitudinal axis, and the drive gear is located on the opposite side axially from the electric motor as the brake gear. Underlying problem.

[0015] The task to be solved is the landing gear of an aircraft or land vehicle with a cost-effective design, simple production and efficient, safe operation.

[0016] Summary of the solution presented here

[0017] This problem is solved by the arrangement specified in the independent device claim and the procedure specified in the independent method claim.

[0018] Such a landing gear of an aircraft or land vehicle is equipped with an axle, a wheel carried by the axle, and a first electromechanical actuator having an output side geared to an input side of a transmission arrangement. The transmission arrangement is switchable between at least two operating modes. In a first mode, the transmission arrangement couples the first electromechanical actuator to a brake arrangement in order to apply or release the brake arrangement so that the brake arrangement can exert a braking torque on the wheel in response to application of the brake arrangement. In a second mode, the transmission arrangement couples the first electromechanical actuator to the wheel in order to rotate the wheel. In a third mode, the transmission arrangement couples the first electromechanical actuator to a fan arrangement acting on the brake arrangement and / or the wheel in order to actuate the latter.In other words, in addition to the axle and the wheel, the chassis includes a dynamic drive / deceleration and ventilation unit with several operating modes.

[0019] In a land vehicle, such a landing gear can be used, for example, as a selectively switchable drive and / or brake in a two- or multi-axle vehicle where only the wheels of some axles are driven. Variants that can also be used in aircraft are also explained below.

[0020] In the case of a landing gear of an aircraft or land vehicle, the first electromechanical actuator is provided in particular for exerting a braking torque on the wheel, for rotating the wheel, and for actuating the fan arrangement. The first electromechanical actuator comprises an electric disc rotor machine with at least one rotor and at least one stator. The at least one rotor and the at least one stator each have at least one end face facing the stator or the rotor. The at least one rotor and / or the at least one stator each have an ironless carrier disk, which each carry field coils or permanent magnets. An air gap is formed between the carrier disk of each rotor and the carrier disk of each stator. The field coils and / or the permanent magnets are aligned in such a way and are fixed to the carrier disk of each rotor orthe carrier disk of each stator is arranged so that the field coils, when current is flowing through them, produce permanent magnets at least temporarily in the same or opposite direction magnetic fields, which cause a rotational or longitudinal relative movement of the rotor to the stator.

[0021] A chassis with an electric disc rotor machine of the above-described design as an electromechanical actuator meets the requirement for a reliable, compact, and lightweight assembly capable of performing a high-torque rotary motion with minimal delay. This machine is suitable for operation with a single- or multi-phase power electronic actuator (converter or inverter).

[0022] Since the electromechanical actuator is only operated briefly (i.e., during takeoff, taxiing, or landing) in the upper power range, the disc rotor machine described here offers significant advantages over known arrangements, such as those provided for in the above-mentioned prior art. For example, short-term operation with start-up times in the millisecond range at very high acceleration and a very high torque density is possible due to the small installation space required. The disc rotor machines described here are very quiet and functionally reliable in the landing gear. Furthermore, they allow simple and sensorless angle or position detection in the machine; their speed / position can be controlled very efficiently. If a torque is to be maintained at standstill, an angle sensor is required.Since there is preferably no iron between the coils / permanent magnets, maximum copper usage is possible to minimize ohmic losses; this increases the power-to-weight ratio (kilowatt / kilogram) of the machine. Furthermore, there is no competition for space between an iron circuit and the field coils. Furthermore, currents cannot be limited by iron saturation; there is only the superposition of the magnetic fields. Any power losses can be absorbed in the conductors of the field coils during the short operating period of the carriage and dissipated during the subsequent idle phase; thus, no forced external cooling is required. A particular advantage of the disc-rotor machines described here is their suitability for multiple overload operation in the carriage at very short intervals.

[0023] Designs, variants and properties

[0024] The disc rotor machines described here can be operated in the chassis both as an electric motor and as an electric generator (for example, in recuperation mode during chassis braking). The disc rotor machines of the type described here can be either externally excited or self-excited. In externally excited machines, one or more excitation windings are provided for excitation. The excitation winding is supplied with energy, for example, by a controlled power source. In a self-excited disc rotor machine, permanent magnets take the place of the excitation windings.

[0025] A separately or self-excited disc rotor machine can be designed as a permanently excited machine in the chassis. Slip rings for supplying electrical power and armature winding(s) can be implemented as a printed circuit on a thin plastic or ceramic disc. In the simplest case, the electrical current is fed directly to the slip rings on the disc via carbon brushes. The disc thus carries the slip rings and the rotor winding(s) and runs in a narrow air gap between stator coils or permanent magnets. To ensure mechanical function, sliding foils can also be arranged in the air gap(s) between the disc(s) and stator coils or permanent magnet(s). A disc rotor machine with permanent magnets (magnetic rotor or stator) is somewhat more expensive in the chassis due to the cost of the permanent magnets, but has the lowest (heat) losses.It is also possible to implement the disc rotor motor as an asynchronous rotor or eddy current rotor in the chassis. While this option is relatively cost-effective, it has higher losses and requires a somewhat more powerful inverter.

[0026] This arrangement allows for a very compact axial arrangement on the outside of the wheel. The control electronics can be located centrally, space-saving, and thermally insulated from the brake disc assembly in the chassis. A pressure piston acting on the brake disc assembly can be designed as several distributed pressure pistons with disc springs for even loading. The control electronics can implement regulation based on an actual braking force specification by measuring the force in the counter bearing of the brake disc assembly in the chassis.

[0027] In one variant, the carrier disk of each rotor and / or the carrier disk of each stator is designed in the chassis as a single-layer or multi-layer circuit board, and the field coils are implemented in one variant as multi-phase conductor tracks, optionally with through-platings, embedded in the carrier disk of each rotor or each stator or at least partially exposed.

[0028] In one variant of the carriage, permanent magnets are embedded or at least partially exposed in the carrier disk of each rotor or stator. These permanent magnets are approximately 0.5 to 15 times, preferably four to twelve times, as high as the air gap in the axial direction. The permanent magnets are preferably designed as rare-earth magnets with a high remanence induction and / or with a high coercive field strength. In one variant, the stator has field coils with three or more phases. The control unit of the carriage is provided in a Variai and is connected to the field coils in such a way that the field coils of one of the carrier disks of each stator can be controlled independently of the field coils of another carrier disk of the stator. Both field coils interact with a permanent magnet carrier disk and must output the currents synchronously.However, the field coils can be designed and controlled as two galvanically isolated systems, resulting in redundancy of the arrangement. If multiple permanent magnet carrier disks are provided, multiple field coils are also required (number of carrier disks + 1). The advantage over two single-disk motors is the elimination of short circuits within the motor. Furthermore, the flux coupling of the magnets with the field coils is improved. This allows for redundancy during braking, increasing the operational reliability of the landing gear (operating mode M1), or for safely driving all driven aircraft wheels to landing speed before landing, which reduces tire wear during landing (a variant of operating mode M2).

[0029] In one variant of the carriage, the carrier disk of each rotor is mounted on a machine shaft in a rotationally fixed manner and movable in the axial direction. This machine shaft can be designed as a hollow shaft coaxially surrounding the wheel axle. In one variant of the carriage, each carrier disk of the rotor and each carrier disk of the stator are arranged so as to be movable relative to one another in the axial direction of the machine shaft. In one variant, the space between or in the field coils of the rotor and / or the stator is ironless. In one variant, ferrous covers are provided in the carriage on both ends of the machine. These covers are designed to absorb high magnetic axial forces and / or to return magnetic flux. Without the iron return conductors, no high forces would be generated and the efficiency of the electrical machine would be reduced.

[0030] In a variant of the chassis, the gear arrangement for the first mode is configured to convert a rotary movement performed by the first electromechanical actuator into a linear movement in order to actuate or release the brake arrangement after coupling the electromechanical actuator with the brake arrangement by means of a trapezoidal, ball, or planetary screw drive.

[0031] In a variant of the chassis, the gear arrangement for the second mode is designed to convert a rotational movement performed by the electro-mechanical actuator into a rotational movement of the wheel after coupling the first electro-mechanical actuator with the wheel.

[0032] In a variant of the chassis, the gear arrangement for the third mode is designed to convert, with the fan arrangement, a rotary movement carried out by the first electro-mechanical actuator into a rotary movement of the fan^.

[0033] In a variant of the chassis, the gear arrangement comprises a second actuator which is configured to non-rotatably couple the rotor of the first electro-mechanical actuator for the first mode to a trapezoidal, ball, or planetary threaded nut of the trapezoidal, ball, or planetary screw drive provided in the gear arrangement in order to convert the rotary movement performed by the electro-mechanical actuator into a linear movement of a threaded spindle in order to actuate or release a brake shoe of the brake arrangement.

[0034] In a variant of the chassis, the second actuator is configured to non-rotatably couple the rotor of the first electro-mechanical actuator to the wheel of the chassis for the second mode in order to convert the rotary movement performed by the electro-mechanical actuator into a rotary movement of the wheel.

[0035] In one variant of the chassis, the second actuator is configured to decouple the rotor of the first electromechanical actuator from the trapezoidal, ball, or planetary threaded nut of the trapezoidal, ball, or planetary threaded drive and from the wheel for the third mode, in order to rotate the fan assembly acting on the brake assembly and / or the wheel, etc., for cooling purposes. In one variant of the chassis, the fan assembly is permanently firmly coupled. In another variant of the chassis, the fan assembly can be switched between firmly coupled and non-coupled to the rotor of the first electromechanical actuator.

[0036] A slotless stator of the electromechanical actuator can have one or more printed circuit boards that serve as field coil and / or electronics mounts for the inverters, and a magnetic return path. This magnetic return path can be made of solid iron, sintered material, or laminated; the latter variants keep core losses low. Especially in designs for low speeds and small inductances, the return path can be made of solid iron.

[0037] A self-excited or permanently excited rotor of the first electromechanical actuator can have a soft magnetic carrier disk, for example, made of soft magnetic steel, to which axially oriented magnetic disk segments, e.g., made of ferrite or plastic-bonded NdFeB, are attached on both sides. Alternatively, the self-excited or permanently excited rotor can be implemented as a continuous magnetic disk magnetized with alternating axial orientations for each pole. For even higher power densities, the disc rotor of the electromechanical actuator presented here is designed as a double-disk rotor with an intermediate stator, which can be equipped with rare-earth magnet segments or corresponding stator windings, for example. This eliminates the axial tensile forces that occur in a single-disk rotor design.

[0038] The first electromechanical actuator with disc rotor motors of the type disclosed here offers high dynamics at a low weight thanks to its iron-free rotor (in one variant). The rotors are either arrangements of (rare earth) permanent magnet elements or have suitably designed field coils. The physical principle underlying disc rotor motors leads to a directly proportional relationship between voltage and speed, as well as current and torque.

[0039] If the stator and, if applicable, rotor coils of the first electromechanical actuator are iron-free, any iron losses are eliminated. The coil inductance can also be significantly reduced. The rotor mass and thus its translational and rotational moment of inertia are also reduced. The machines have low noise emissions, high electromagnetic compatibility (EMC), and no reluctance torque. Finally, the disc rotor machines of the electromechanical actuator have a short axial length. Heat loss occurring in the stator can also be dissipated relatively easily to the outside.

[0040] The rotor and / or stator windings can be implemented as printed, stamped, or etched conductor tracks on / in single- or multi-layer printed circuit boards. Embedding prefabricated air-core coils made of wire or sheet metal (copper, aluminum, etc.) in fiber-reinforced plastic (epoxy, ceramic, PTFE, polyimide) is also possible. The stator and rotor disks with the coils can be provided with friction-increasing or friction-reducing insulating coatings.

[0041] By constructing the stator field coils as multilayer boards, a high copper fill factor with high mechanical strength is possible. The required number of turns can be achieved by implementing the field coils in several multilayer layers. The spacing of the conductor tracks should be minimized, taking into account the mechanical and electrical constraints, for example, to approximately twice the conductor track thickness; this reduces the dead space on and in the carrier disks. Furthermore, the multilayer coil structure can be realized using through-hole plating in the form of vias.

[0042] The mechanical design of the first electromechanical actuator is very simple and cost-effective to implement, as the lamination of the magnetic return paths is eliminated, there are no grooves, and the materials are efficacious. In another variant of the first electromechanical actuator, cost-effective powdered iron or tape winding are used for the magnetic return paths.

[0043] With the disc rotor machine presented here as the first electro-mechanical actuator, its properties mean that mechanical components for transmitting forces and torques - apart from the screw drive for converting the rotary movement into a longitudinal movement - such as gears or locking mechanisms, can be dispensed with, particularly in the second or third operating mode. This makes the electric machine easy to integrate into the chassis equipment. While omitting an ABS function, a further variant provides for the first electro-mechanical actuator to be blocked in braking mode with an additional, actuatable mechanical rotor brake. A disc spring loaded on the axially movable rotor maintains the braking pressure, and the power supply to the first electro-mechanical actuator can be switched off. The braking forces for fixing the rotor are comparatively low due to the high power transmission ratio of the (ball) threaded spindle.

[0044] The carrier plate of each rotor and / or the carrier plate of each stator of the electromechanical actuator can be designed as a single-layer or multi-layer circuit board. The field coils can have single-phase or multi-phase conductor tracks containing non-ferrous metal, optionally with vias, embedded in the carrier plate of each rotor or each stator or at least partially exposed.

[0045] In a variant of the disc rotor machine, the space between or in the field coils of the rotor and / or the stator can be designed without iron.

[0046] In one variant, ferrous covers can be provided on both ends of the machine, which can be designed to absorb high magnetic axial forces. These axial forces can result from, for example, 5–20 bar of magnetic axial pressure during operation. For this purpose, the ferrous covers can be designed to be sufficiently torsionally and flexurally rigid, for example, using reinforcing ribs. Alternatively or additionally, each or just one of the ferrous covers can be designed to recirculate the magnetic flux. These measures lead to a reduction in ohmic losses as long as magnetic saturation effects have not yet occurred.

[0047] In another variant, the disc rotor machine of the electromechanical actuator can be formed from an even number of symmetrical machines arranged axially one behind the other. In this case, the magnetic flux feedback and / or the current feedback of an even-numbered machine can take place in the stator of an odd-numbered machine. In other words, in an arrangement of two or more

[0048] Current of the even-numbered machine is fed back into the stator of the odd-numbered machine.

[0049] The arrangement and operation of the landing gear disclosed here makes it possible to produce a more electrified aircraft than before, which can be realized with a small number of parts and without the previously required landing gear hydraulics.

[0050] The design of the brake disc package and the wheel suspension of the chassis can remain unchanged compared to conventional chassis.

[0051] The mechanical force / torque generation by means of the electro-mechanical actuator takes place centrally on the chassis axle instead of several distributed hydraulic cylinders.

[0052] The brake application force is generated using an electric disc rotor machine as described above as an electro-mechanical actuator.

[0053] The electric disc rotor machine of the first electro-mechanical actuator is firmly coupled to the screw drive via a sliding seat for braking operation.

[0054] By unlocking the sliding seat of the screw drive nut, the electric disc rotor machine of the first electro-mechanical actuator allows fan operation.

[0055] The electric disc rotor machine is firmly coupled to the landing gear rim for taxiing or landing with the wheels already pre-accelerated, ideally to touchdown speed.

[0056] The chassis presented here enables, among other things, the implementation of an integrated brake, fan, and wheel drive function. However, partial solutions such as a pure brake function are also feasible.

[0057] The high dynamics of the electric disc rotor machine also allows the implementation of an anti-lock braking system for the chassis and precise braking force adjustment for each wheel.

[0058] Automatic wear adjustment must also be implemented for the braking system.

[0059] In a method for operating the landing gear of an aircraft or land vehicle having an axle, a wheel carried by the axle, and a first electromechanical actuator which is gear-connected on the output side to an input side of a transmission arrangement, the transmission arrangement is switched between at least two operating modes in order to couple the electromechanical actuator to a brake arrangement in a first operating mode in order to apply or release the brake arrangement, wherein the brake arrangement is arranged and configured to exert a braking torque on the wheel in response to an application of the brake arrangement; and / or in a second operating mode to couple the electromechanical actuator to the wheel in order to rotate the wheel; and / or in a third operating mode to couple the electromechanical actuator to a fan arrangement acting on the brake arrangement and / or the wheel in order to apply the same.

[0060] Further features, characteristics, advantages and possible modifications of this electrical machine and its mode of operation are explained in the following description, which refers to the attached drawings.

[0061] The variants of the chassis described here, as well as their functional and operational aspects, serve only to better understand their structure, functionality, and properties; they do not limit the disclosure to the exemplary embodiments. The figures are partly schematic, with essential properties and effects sometimes shown significantly enlarged to clarify the functions, operating principles, technical designs, and features. Each functionality, principle, technical design, and feature disclosed in the figures or in the text can be freely and arbitrarily combined with all claims, each feature in the text and in the other figures, other functionality, principles, technical designs, and features contained in or resulting from this disclosure, so that all conceivable combinations can be assigned to the described devices.This also encompasses combinations between all individual embodiments in the text, i.e., in every section of the description, in the claims, and also combinations between different variants in the text, in the claims, and in the figures, and can be made the subject of further claims. The claims also do not limit the disclosure and thus the possible combinations of all the features shown with each other. All disclosed features are explicitly disclosed here, both individually and in combination with all other features.

[0062] Short description of the characters

[0063] Fig. 1 shows a landing gear in a schematic side view.

[0064] Figs. 2 - 4 show the chassis in a schematic side view with a variant of the first electro-mechanical actuator and the gear arrangement in different operating modes M1 - M3. Detailed description of variants of the chassis and its operation

[0065] Fig. 1 illustrates, in a schematic longitudinal section, a landing gear 100 of an aircraft or land vehicle with an axle 102 having a central longitudinal axis M. This axle 102 carries a wheel 104 comprising a rim 104a and a tire 104b. A first electromechanical actuator 110 is assigned to the landing gear 100, which is gear-connected on the output side 112 to an input side 132 of a transmission arrangement 130. The transmission arrangement 130 can be switched between at least two, in the present variant between three, operating modes M1, M2, M3.

[0066] The transmission arrangement 130 is to be brought into a first operating mode M1, controlled by a control unit CU. In the first operating mode M1, the transmission arrangement 130 couples the first electromechanical actuator 110 to a brake arrangement 106 of the chassis 100 in order to apply or release this brake arrangement 106. The brake arrangement 106 serves to exert a braking torque on the wheel 104 in response to an actuation of the brake arrangement 106 by the first electromechanical actuator 110.

[0067] The transmission assembly 130 is to be brought into a second operating mode M2, controlled by the control unit CU. In this second operating mode M2, the transmission assembly 130 couples the first electromechanical actuator 110 to the wheel 104, more precisely to the rim 104a of the wheel 104, in order to set the wheel 104 in rotation via the electromechanical actuator 110.

[0068] The transmission assembly 130 is to be switched to a third operating mode M3, controlled by the control unit CU. In this third operating mode M3, the transmission assembly 130 couples the electromechanical actuator 110 to a fan assembly 120, in order to actuate the latter via the first electromechanical actuator 110. In one variant, the fan assembly 120 is aerodynamically designed to assist in driving the wheel, particularly during landing approach. The fan assembly 120 here comprises a ring of fan blades. This ring of fan blades is directed toward the brake assembly 106 and / or the wheel 104 and / or the control unit CU and / or the electromechanical actuator 110 in order to cool them.

[0069] Fig. 2 shows a variant of the chassis 100 with the first electromechanical actuator 110 and the gear arrangement 130. The first electromechanical actuator 110 is an electrical machine in the form of a disc rotor machine. This disc rotor machine has a circular rotor 114 in plan view and a stator 116 corresponding to the rotor 114 and circular in plan view. In this variant, the rotor 114 has a carrier disk 114'. In this variant, the stator has two carrier disks 116, 116', which are arranged on either side of the carrier disk 114' of the rotor 114. In this variant, the carrier disk 114' of the rotor 114 carries permanent magnets 114a, and the carrier disks 116' of the stator 116 carry stator field coils 116a.In other externally excited variants of the disc rotor machine, not shown in detail here, rotor field coils replace the permanent magnets 114a of the rotor 114.

[0070] The rotor 114 and the stator 116, more precisely their respective support disks 114', 116', each have a mutually facing end face 1141, 1142; 1161, 1162. An air gap 118 is formed between the rotor support disk 114' and an adjacent stator support disk 116'.

[0071] The stator field coils 116a or the permanent magnets 114a are aligned and arranged on the carrier disk 14' of each rotor 114 or the carrier disk 116' of each stator 116 such that the field coils 116a, when current flows through them, and / or the permanent magnets 114a at least temporarily produce magnetic fields in the same or opposite directions, which cause a rotational movement of the rotor 114 relative to the stator 116.

[0072] The disc rotor machine of the first electromechanical actuator 110 has a housing shell 116c, on whose inner surfaces the stator 116 is formed, and which encloses the rotor 114. The housing shell is made of iron and also serves as a magnetic flux return. In another variant, an aluminum housing and a high-quality wound sheet metal return wire are provided to save weight and reduce magnetic losses.

[0073] The carrier disk 114' of each rotor 114 is made of iron or at least contains iron; the carrier disk 116' of each stator 116, in the illustrated variant, is formed as a multilayer circuit board made of glass-fiber-reinforced epoxy. The permanent magnets 114a are embedded in the carrier disk 114' of the rotor 114, and the field coils 116a are multiphase, copper-containing conductor tracks with vias (not shown) embedded in the carrier disk 116' of each stator 116. Depending on the number of electrical phases of the machine, the conductor tracks (not shown) are circular-ring-segment-shaped spiral tracks that generate a rotating field and are embedded in the carrier disk 116' of the stator 11 or arranged on its surface(s). The space of the stator 116 located between or within the field coils 116a is ironless.

[0074] The rotor 114 has at its center a tubular bearing flange 114f, which captively supports the carrier disk 114' of the rotor 114 and two inner Lac rolling bearings 114w' and 114w" in the radial direction on the outside. The two outer bearing rings of the rolling bearings 114w' and 114w" are captively supported in the longitudinal and circumferential directions on the housing shell 116c of the stator 116 and allow the rotor 114 to rotate relative to the stator 116. The housing shell 116c of the stator 116 is mounted externally on a support tube 116r that is bent towards the axis 102, in a rotationally fixed manner and displaceable in the longitudinal direction of the central longitudinal axis M on the axis 102. The support tube 116r is captively attached to the axis 102 in the longitudinal and circumferential directions.

[0075] A linear drive 136 controlled by the control unit CU is assigned to the gear assembly 130. This linear drive 136 displaces the housing shell 116c of the stator 116, and thus the first electromechanical actuator 110 as a whole, along the axis 102 on a surface-treated outer sliding surface 116v of the support tube 116r. This allows the three operating modes M1, M2, and M3 to be adopted.

[0076] The bearing flange 114f has a radially inwardly directed gear ring 114z at one end (right in Figs. 2-4). This radially inwardly directed gear ring 114z is engaged or disengaged with a radially outwardly directed gear ring 138z arranged on a threaded nut 138m of a ball screw drive 138, depending on the axial positioning of the electromechanical actuator 110 along the axis 102.

[0077] When the two gear rings 114z and 138z are in engagement with each other, as illustrated in Fig. 3, rotation of the electromechanical actuator 110 causes a hollow spindle 138h of the ball screw drive 138, which is guided longitudinally on the axis 102, to move along the axis 102 depending on the direction of rotation of the electromechanical actuator 110. The rotating threaded nut 138m of the ball screw drive 138 does not change its position in the longitudinal direction. The hollow spindle 138h of the ball screw drive 138 has at one end (on the right in Figs. 2 - 4) an annular thrust piston 106a that is offset away from the axis 102 and acts on a stack of brake discs 106c. The rotation of the rotor 114 rotates the threaded nut 138m of the ball screw drive 138. As a result, the longitudinally displaceable hollow spindle 138h of the ball screw drive 138 and with it the annular thrust piston 106a move along the axis 102 (Fig.3 to the right) and compresses the brake assembly 106.

[0078] The stack of brake discs 106c comprises a plurality of brake discs 106c, which are alternately fastened to a rim 104a of the wheel 104 and received in a receptacle 106c of the brake assembly 106. The receptacle 106c of the brake assembly 106 is L-shaped in cross-section. It is attached to the axle 102 in a rotationally fixed and longitudinally immovable manner. With the position of the ball screw drive 138 and the electromechanical actuator 110 illustrated in Fig. 3, it is possible to implement the first operating mode M1. In the first operating mode M1, the first electromechanical actuator 110 is coupled to the brake assembly 106 by the linear drive 136 in order to apply or release it. After coupling, upon rotation of the first electro-mechanical actuator 110, the brake assembly 106 can apply or reduce a braking torque to the wheel 104.

[0079] To enter the second operating mode M2, in which the electromechanical actuator 110 couples to the wheel 104, the electromechanical actuator 110 is displaced by the linear drive 136 in the direction of the rim 104a (to the far right in Fig. 4) so ​​far that a drive ring 114r with pins 114s, which is arranged in a rotationally fixed manner at the end (to the far right in Fig. 4) of the tubular bearing flange 114f, engages in diametrically opposed openings 104o in the rim of the wheel 104. In this position, the two gear rings 114z and 138z must no longer be engaged. Thus, a second operating mode M2 ​​is realized, in which the electromechanical actuator 110 is pushed toward the wheel 104 by the linear drive 136 so that the electromechanical actuator 110 is rotationally coupled to the wheel 104. In this position, rotation of the electromechanical actuator 110 causes the wheel 104 to rotate about the axis 102.

[0080] Between the housing shell 116c and the wheel 104, the tubular bearing flange 114f supports a fan assembly 120. When the first electromechanical actuator 110 rotates, the fan assembly 120 also rotates. In the variant shown in Fig. 2b, the fan assembly 120 is permanently and firmly coupled to the tubular bearing flange 114f. In other variants, the fan assembly 120 can be switched between permanently and non-coupled to the rotor 114a of the first electromechanical actuator 110. Through all these variants, the third operating mode M3 can be realized, in which the first electro-mechanical actuator 110 is coupled or is to be coupled to the blower arrangement 120 acting on the brake arrangement 106 and / or the wheel 104 in order to actuate the blower arrangement 120.

Claims

Patent claims 1. Landing gear (100) of an aircraft or land vehicle with - an axis (102); - a wheel (104) carried by the axle (102); - an electro-mechanical actuator (110) which is gear-connected on the output side (112) to an input side (132) of a gear arrangement (130); wherein - the gear arrangement (130) is switchable between at least two operating modes (M1, M2, M3) and is designed to (i) in a first operating mode (Ml), to couple the electromechanical actuator (110) to a brake arrangement (106) in order to actuate or release the same, wherein the brake arrangement (106) is arranged and configured to exert a braking torque on the wheel (104) in response to actuation of the brake arrangement (106); and / or (ii) in a second operating mode (M2), to couple the electro-mechanical actuator (110) to the wheel (104) to rotate the wheel (104); and / or (iii) in a third operating mode (M3), to couple the electromechanical actuator (110) to a blower arrangement (120) acting on the brake arrangement (106) and / or the wheel (104) in order to actuate them.

2. Landing gear (100) of an aircraft or land vehicle, in particular according to claim 1, wherein - the electro-mechanical actuator (110) (i) for applying a braking torque to the wheel (104), and / or (ii) to rotate the wheel (104), and / or (iii) for actuating the fan assembly (120) comprises an electric disc rotor machine having at least one rotor (114a) and at least one stator (124); - the at least one rotor (114a) and the at least one stator (124) each have a mutually facing end face (114aa, 114ab; 124a, 124b); - the at least one rotor (114a) and / or the at least one stator (124) each have an ironless carrier disc (114a', 124'), which each carry field coils (126a) or permanent magnets (114a); an air gap (128) is formed between the carrier disc (114a') of each rotor (114a) and the carrier disc (124') of each stator (124); - the field coils (126) and / or the permanent magnets (114a) are aligned and arranged on the carrier disc (114a') of each rotor (114a) or the carrier disc (124') of each stator (124) in such a way that the field coils (126) in the flow flowing state and / or the permanent magnets (114a) temporarily produce magnetic fields in the same or opposite direction, which cause a rotational or longitudinal relative movement of the rotor (114a) to the stator (124).

3. Landing gear (100) of an aircraft or land vehicle, in particular according to claim 2, wherein - the carrier disk (114a') of each rotor (114a) and / or the carrier disk (124') of each stator (124) is designed as a single-layer or multi-layer circuit board, or in the case of permanent magnets (114a) is designed as a ferromagnetic carrier disk, and the field coils (126) have multi-phase conductor tracks, optionally with through-contacts, embedded or at least partially exposed in the carrier disk (114a'; 124') of each rotor (114a) or each stator (124).

4. Landing gear (100) of an aircraft or land vehicle, in particular according to claim 2 or 3, wherein - permanent magnets (114a) embedded or at least partially exposed in the carrier disk of each rotor (114a) or each stator (124) are provided as permanent magnets (114a), which are approximately 0.5 to 15 times, preferably four to twelve times, as high as the air gap (128) in the axial direction; - the permanent magnets (114a) are preferably designed as rare-earth magnets with a high remanence induction and / or with a high coercive field strength; and / or - the stator (124) has three-phase or higher-phase field coils (126); and / or - a control unit (CU) is provided which is configured and connected to the field coils (126) in such a way that the field coils (126) of one of the carrier discs (124') of each stator (124) can also be controlled synchronously, independently of the field coils (126) of another carrier disc (124') of the stator (124).

5. Landing gear (100) of an aircraft or land vehicle, in particular according to claim 2, 3 or 4, wherein - the carrier disc of each rotor is mounted on a machine shaft in a rotationally fixed and axially movable manner; and / or - each carrier disc of the rotor and each carrier disc of the stator are arranged to be movable relative to one another in the axial direction of the machine shaft; and / or the space of the rotor (14) and / or the stator (16) located between or in the field coils (116a) is ironless; and / or iron-containing covers are provided on both end faces of the machine, which (i) are designed to absorb high magnetic axial forces, i (ii) are designed for magnetic flux feedback.

6. Landing gear (100) of an aircraft or land vehicle, in particular according to one of claims 1 to 5, wherein - the gear arrangement (130) for (i) the first mode (Ml) is configured, after coupling the electromechanical actuator (110) to the brake assembly (106), to convert a rotary movement performed by the electromechanical actuator (110) into a linear movement by means of a trapezoidal, ball, or planetary screw drive in order to actuate or release the brake assembly (106); and / or - the gear arrangement (130) for (ii) the second mode (M2) is configured to convert a rotational movement performed by the electromechanical actuator (110) into a rotational movement of the wheel (104) after coupling the electromechanical actuator (110) to the wheel (104); and / or - the gear arrangement (130) for (iii) the third mode (M3) is configured to convert, after coupling the electromechanical actuator (110) to the fan assembly (120), a rotary movement performed by the electromechanical actuator (110) into a rotary movement of the fan assembly (120).

7. Landing gear (100) of an aircraft or land vehicle, in particular according to one of claims 1 to 6, wherein - the gear arrangement (130) comprises a second actuator (150) which is designed to drive the rotor (114a) of the electro-mechanical actuator (110) (i) for the first mode (Ml), to be coupled in a rotationally fixed manner to a trapezoidal, ball, or planetary threaded nut () of the trapezoidal, ball, or planetary screw drive in order to convert the rotational movement performed by the electromechanical actuator (110) into a linear movement of a threaded spindle () in order to actuate or release a brake shoe of the brake arrangement (106); the rotor (114a) of the electromechanical actuator (110) (ii) for the second mode (M2) to be rotationally fixedly coupled to the wheel (104) in order to convert the rotational movement performed by the electromechanical actuator (110) into a rotational movement of the wheel (104); the rotor (114a) of the electromechanical actuator (110) (iii) for the third mode (M3) from the trapezoidal, ball, or planetary screw nut () of the trapezoidal, ball, or planetary screw drive and from the Wheel (104) to decouple the force acting on the brake assembly (106) wheel (104) acting fan arrangement (120) to rotate; wherein - the fan arrangement (120) is optionally permanently coupled or can be switched between permanently coupled and uncoupled to the rotor (114a) of the electromechanical actuator (110).

8. A method for operating a landing gear (100) of an aircraft or land vehicle having an axle (102); a wheel (104) carried by the axle (102); and an electromechanical actuator (110) which is gear-connected on the output side (112) to an input side (132) of a transmission arrangement (130); wherein - the gear arrangement (130) is switched between at least two operating modes (M1, M2, M3) in order to (i) in a first operating mode (Ml), to couple the electromechanical actuator (110) to a brake arrangement (106) in order to actuate or release the same, wherein the brake arrangement (106) is arranged and configured to exert a braking torque on the wheel (104) in response to actuation of the brake arrangement (106); and / or (ii) in a second operating mode (M2), to couple the electro-mechanical actuator (110) to the wheel (104) to rotate the wheel (104); and / or (iii) in a third operating mode (M3), to couple the electromechanical actuator (110) to a blower arrangement (120) acting on the brake arrangement (106) and / or the wheel (104) in order to actuate them.

Images