Landing gear of an aircraft or land vehicle

Abstract

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

Description

Introduction

[0001] This document describes the landing gear of an aircraft or land vehicle. Such a landing gear also includes a dynamic drive / deceleration and ventilation unit. Details 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. background

[0002] Modern aircraft have wheel brakes that engage after aerodynamic devices have begun to exert their braking effect. These aerodynamic devices include retractable flaps on the wingtips, with the extension of the flaps counteracting the aircraft's lift while simultaneously increasing its drag. Another aerodynamic device is thrust reversal, generated by devices on the aircraft's engines that create reverse thrust during landing, which also slows the aircraft. When the wheels touch down on the runway, the initially stationary wheels are typically brought up to the aircraft's speed, and then the braking torque is transferred to the runway via the wheels. This process results in significant tire wear. Furthermore, 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 cool down safely, e.g. by means of an external fan directed at the wheel brake from the outside while in the parking position.

[0003] Commercial aircraft are typically equipped with hydraulic braking systems. These require large hydraulic pressure generators and reservoirs for landing and aborted takeoffs, which increase the aircraft's mass. Therefore, several concepts for electrically or electromechanically actuated braking systems are known.

[0004] Currently, aircraft tugs typically handle the task of reversing aircraft from the gate. They position the planes so they can taxi to the runway using their engines. Taxiing to the runway consumes up to 700 kilograms of kerosene or more, depending on the aircraft type. To reduce fuel consumption and noise pollution during taxiing, electric motors were installed in the main landing gear of a commercial aircraft for testing purposes. These motors serve as the drive for taxiing on the ground. This eliminates the need for an aircraft tug to reverse from the gate and taxi to and from the runway. The electric motors are controlled from the cockpit. The auxiliary power unit (APU), which also supplies the rest of the aircraft's power, provides the electric motors with energy. State of the art

[0005] US Patent 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 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.

[0006] CA 2 845 205 C (Messier-Bugatty-Dowty) relates to an electromechanical actuator for a vehicle brake, comprising a first and a second part that are separable from one another. The first part includes an electric motor and connecting means for attaching the actuator to an external control device, and the second part includes a plunger that slides out of the first part of the housing and protrudes from the second part through a central opening. The first and second parts are coupled such that the motor interacts with the plunger to cause movement of the plunger in response to an action of the motor. The second part includes a second element consisting of two parts.

[0007] EP 2 666 717 A2 (Goodrich) relates to a system comprising an electric motor coupled to a first gearbox, a first clutch for selectively engaging the first gearbox with a drive gearbox, and a braking system, wherein, in response to engagement with the drive gearbox, 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 stack of brake discs. The system further comprises an aircraft wheel, wherein the drive gearbox causes the rotation of the aircraft wheel. Another system comprises an aircraft wheel having an engagement area for interacting with a drive gearbox, wherein the aircraft wheel is coupled to an aircraft brake.The aircraft brake comprises 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 engages the drive gear with the aircraft wheel. Part of the clutch has a toothed section. The rotating element of the clutch is driven by an electric motor. The braking system has a ball screw and a plunger. The braking system has a second gearbox coupled to the ball screw. Either the drive gear or the second gearbox has a variable gear ratio. The first clutch has a neutral position in which the first gearbox is not engaged with either the braking system or the drive gear.

[0008] EP 3 453 613 A1 (Goodrich) relates to an aircraft with a landing gear comprising a wheel, a friction brake with brake material coupled to the wheel, a regenerative brake with a reversible rolling motor, a sensor for measuring a wheel parameter, a friction brake temperature, and memory for communicating with a control unit. The memory stores instructions that cause the control unit to perform the following operations: receiving a command signal, the wheel parameter, and the friction brake temperature; calculating a brake 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 brake material temperature and the command signal.

[0009] EP 3 121 077 A1 (Goodrich) relates to a braking and rolling system with an electric motor having a first and a second output shaft, a clutch for selectively coupling the electric motor with at least one drive gearbox and a brake gearbox. In response to coupling with the drive gearbox, the electric motor drives only an aircraft wheel via the first output shaft, and in response to coupling with the brake gearbox, it drives only a brake tensioning system via the second output shaft to exert force on a brake disc stack. The drive gearbox is located on the opposite side of the electric motor from the brake gearbox. The electric motor, drive gearbox, and brake gearbox are concentrically aligned. The brake tensioning system and the brake gearbox each have a ball screw drive and a plunger. The first and second output shafts are arranged concentrically.The drive gearbox causes the aircraft wheel to rotate. The drive gearbox, or brake gearbox, is a high-ratio gearbox, ranging from approximately 30:1 to approximately 110:1. The drive gearbox or brake gearbox incorporates a planetary gear set. The system includes an aircraft wheel with a connecting section for linking to the drive gearbox. The aircraft wheel is coupled to an aircraft brake. The aircraft brake has a brake tensioning system for selective coupling with a brake disc stack, and a clutch for selective coupling of an electric motor to the drive gearbox or brake gearbox. The electric motor has a central longitudinal axis, and the drive gearbox is located axially opposite the electric motor to the brake gearbox.

[0010] US Patent 6,450,448 B1 discloses a drive unit for an aircraft landing gear wheel, comprising a pneumatic motor with a first impeller driven by the pneumatic energy of compressed air and a second impeller rotated by the expanded exhaust air from the first impeller. These impellers are mounted on the wheel axle and rotate together with a third impeller within an airtight housing. A stationary blade is positioned between the second and third impellers. The pneumatic motor has two functions: as a pneumatic motor, driven by the pneumatic energy of compressed air, and as a vacuum brake. By closing the compressed air inlet, the vacuum brake creates a vacuum within the airtight housing, driving the impellers through the force of the rotating landing gear wheel, which is driven by ground contact during landing. Underlying problem

[0011] The task to be solved is the chassis of an aircraft or land vehicle with a cost-effective design, simple manufacturing and efficient, safe operation. Summary of the solution presented here

[0012] This problem is solved by the arrangement specified in the independent apparatus claim and the procedure specified in the independent method claim.

[0013] Such a landing gear of an aircraft or land vehicle is equipped with an axle, a wheel supported by the axle, and a first electromechanical actuator having an output side that is mechanically connected to an input side of a gearbox assembly. The gearbox assembly is switchable between at least two operating modes. In a first mode, the gearbox assembly couples the first electromechanical actuator to a brake assembly to actuate or release it, so that the brake assembly can exert a braking torque on the wheel in response to actuation of the brake assembly. In a second mode, the gearbox assembly couples the first electromechanical actuator to the wheel to rotate the wheel. In a third mode, the gearbox assembly couples the first electromechanical actuator to a fan assembly acting on the brake assembly and / or the wheel to actuate it.In other words, in addition to the axle and wheel, the chassis includes a dynamic drive / deceleration and ventilation unit with multiple operating modes.

[0014] In a land vehicle, such a chassis can be used, for example, as an optionally engaged 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 an aircraft are described below.

[0015] In the 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 assembly. 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 and / or the rotor, respectively. The at least one rotor and / or the at least one stator each have an ironless carrier disk, each of which carries 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 and mounted on the carrier disk of each rotor and / or stator in such a way as to...the carrier disk of each stator is arranged so that the field coils in the current-carrying state and / or the permanent magnets at least temporarily generate magnetic fields in the same or opposite directions, which cause a rotational or longitudinal relative movement of the rotor to the stator.

[0016] A chassis with an electric disc rotor machine of the design described above, acting as an electromechanical actuator, fulfills the requirement for a reliable, compact, and lightweight arrangement capable of executing a rotary motion with high torque with minimal delay. This machine is suitable for operation with a single- or multi-phase power electronic actuator (converter or inverter).

[0017] Since the electromechanical actuator is only operated briefly (i.e., during takeoff, taxiing, or landing) at its upper power range, the disc rotor machine described here offers significant advantages over known arrangements, such as those described in the prior art mentioned above. For example, short-term operation with start-up times in the millisecond range is possible with very high acceleration and a very high torque density due to the small installation space required. These disc rotor machines are very quiet and reliable within the landing gear. Furthermore, they allow for simple and sensorless measurement of rotation angle or displacement within the machine; their speed / displacement can be controlled very efficiently. If torque needs to be maintained while stationary, 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 (kilowatts / kilogram) of the machine. Furthermore, there is no space competition between an iron circuit and the field coils. Additionally, currents cannot be limited by iron saturation; there is only the superposition of the magnetic fields. Any power loss generated during the short operating time of the landing gear can be absorbed in the conductors of the field coils 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 operations in the landing gear at very short intervals. Designs, variants and properties

[0018] The disc rotor machines described here can be operated in the chassis as both an electric motor and an electric generator (for example, in recuperation mode during chassis braking). These disc rotor machines can be either externally excited or self-excited. Externally excited machines have one or more excitation windings. The excitation winding is supplied with energy, for example, by a controlled current source. In a self-excited disc rotor machine, permanent magnets replace the excitation windings.

[0019] A disc rotor machine, whether externally or self-excited, can be designed as a permanent magnet machine within the chassis. Slip rings for supplying electrical power and the 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 supplied 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 films can also be arranged in the air gap(s) between the disc(s) and the stator coil(s) or permanent magnet(s). While 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, it has the lowest (heat) losses.It is also possible to implement the disc rotor machine as an asynchronous rotor or eddy current rotor in the chassis. While this variant is relatively inexpensive, it has higher losses and requires a somewhat more powerful inverter.

[0020] This arrangement allows for a very compact axial design of the chassis components on the outer side of the wheel. The control electronics can be centrally located within the chassis, thermally insulated from the brake disc assembly, and thus space-saving. A pressure piston acting on the brake disc assembly can be designed as several distributed pressure pistons with disc springs for even load distribution. The control electronics can regulate the braking force based on an actual braking force specification by measuring the force at the counter bearing of the brake disc assembly within the chassis.

[0021] The carrier disk of each rotor and / or the carrier disk of each stator is designed in one variant in the chassis as a single-layer or as a multi-layer circuit board, and the field coils are implemented in one variant as multi-phase conductor tracks embedded in the carrier disk of each rotor or each stator or at least partially exposed, possibly with vias.

[0022] In one variant of the chassis, permanent magnets are embedded in 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, the height of the air gap in the axial direction. The permanent magnets are preferably rare-earth magnets with high remanence induction and / or high coercive field strength. In one variant, the stator has field coils configured with three or more phases. In one variant, the chassis control unit is designed and 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 same stator. Both field coils interact with a permanent magnet carrier disk and must output the currents synchronously.The field coils can, however, be designed and controlled as two galvanically isolated systems, resulting in redundancy of the arrangement. If multiple permanent magnet carrier discs are used, multiple field coils are also required (number of carrier discs +1). The advantage over two single-disc motors is the elimination of feedback loops within the motor. Additionally, the flux coupling between the magnets and the field coils is improved. This allows for redundancy during braking, increasing the operational safety of the landing gear (operating mode M1), or for safely accelerating all driven aircraft wheels to landing speed before touchdown, thus reducing tire wear during landing (a variant of operating mode M2).

[0023] In one variant of the chassis, the support disk of each rotor is mounted on a machine shaft in a rotationally fixed manner but with axial movement. This machine shaft can be designed as a hollow shaft coaxially surrounding the wheel axle. In another variant of the chassis, each rotor support disk and each stator support disk are arranged to move axially relative to each other along the machine shaft. In another variant, the space between or within the field coils of the rotor and / or stator is ironless. In yet another variant, the chassis incorporates iron-containing covers on both end faces of the machine, designed to absorb high axial magnetic forces and / or to provide magnetic flux feedback. Without these iron-containing covers, high forces would not be generated, and the efficiency of the electric machine would be reduced.

[0024] In one variant of the chassis, the gear arrangement for the first mode is designed 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.

[0025] In one variant of the chassis, the gearbox arrangement for the second mode is designed to convert a rotary movement performed by the electromechanical actuator into a rotary movement of the wheel after the first electromechanical actuator has been coupled to the wheel.

[0026] In one variant of the chassis, the gearbox arrangement for the third mode is designed to convert a rotary movement performed by the first electromechanical actuator into a rotary movement of the blower arrangement.

[0027] In one variant of the chassis, the gear arrangement includes a second actuator, which is designed to couple the rotor of the first electromechanical actuator for the first mode to a trapezoidal, ball, or planetary threaded nut of the trapezoidal, ball, or planetary threaded drive provided in the gear arrangement in a rotationally fixed manner, in order to convert the rotary motion performed by the electromechanical actuator into a linear motion of a threaded spindle in order to actuate or release a brake shoe of the brake arrangement.

[0028] In one variant of the landing gear, the second actuator is designed to couple the runner of the first electro-mechanical actuator to the wheel of the landing gear in a rotationally fixed manner for the second mode, in order to convert the rotary movement performed by the electro-mechanical actuator into a rotary movement of the wheel.

[0029] In one variant of the chassis, the second actuator is configured to decouple the rotor of the first electromechanical actuator from the trapezoidal, spherical, or planetary threaded nut of the trapezoidal, spherical, or planetary threaded drive and from the wheel in order to actuate the cooling fan assembly acting on the brake assembly and / or the wheel, etc., by rotating it. In one variant of the chassis, the fan assembly is permanently coupled. In another variant of the chassis, the fan assembly can be switched between being permanently coupled and uncoupled with the rotor of the first electromechanical actuator.

[0030] A slotless stator of the electromechanical actuator can have one or more printed circuit boards that serve as field coil and / or electronics carriers 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 remagnetization losses low. Particularly in designs for low speeds and low inductions, the return path can be made of solid iron.

[0031] A self-excited or permanent magnet 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 polymer-bonded NdFeB, are attached on both sides. Alternatively, the self-excited or permanent magnet rotor can be implemented as a continuous magnetic disk that is magnetized in an alternating axial orientation with respect to the poles.

[0032] For even higher power densities, the disc rotor machine of the electromechanical actuator presented here is designed as a double-disc rotor with an intermediate stator, which is equipped, for example, with rare-earth magnet segments or corresponding stator windings. This eliminates the axial tensile forces that occur in a single-disc rotor design.

[0033] The first electromechanical actuator with disc rotor machines of the type disclosed here offers high dynamics at a low weight due to its iron-free rotor (in one variant). The rotors are either arrays of (rare-earth) permanent magnet elements or have suitably designed field coils. The underlying physical principle of the disc rotor machines results in a directly proportional relationship between voltage and rotational speed as well as current and torque.

[0034] 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 moments of inertia, are likewise reduced. The machines exhibit low electromagnetic interference (EMI), 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.

[0035] 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 (copper, aluminum, or similar) wire or sheet material in (fiber-reinforced) plastic material (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.

[0036] By constructing the stator field coils as multilayer circuit 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 multiple multilayer layers. Advantageously, 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 within the substrate. Furthermore, the multilayer coil structure can be implemented using vias.

[0037] The machine design of the first electromechanical actuator is very simple and cost-effective to implement, as the lamination of the magnetic return paths is unnecessary, no grooves are required, and materials are used efficiently. In another variant of the first electromechanical actuator, cost-effective powdered iron or coiled strips are used for the magnetic return paths.

[0038] With the disc rotor machine presented here, the first electromechanical actuator, its properties allow for the elimination of mechanical components for transmitting forces and torques—apart from the lead screw for converting rotary motion into linear motion—such as gears or locking mechanisms, particularly in the second or third operating mode. This makes the electric machine easy to integrate into the chassis equipment. In a further variant, and without an ABS function, the first electromechanical actuator is to be locked in braking mode with an additional, actuated mechanical rotor brake. A disc spring bearing on the axially displaceable rotor maintains the brake pressure, and the power supply to the first electromechanical actuator can be switched off. The braking forces required to lock the rotor are comparatively low due to the high force transmission of the (ball) lead screw.

[0039] The carrier disk of each rotor and / or the carrier disk 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 metals, optionally with vias, embedded in or at least partially exposed in the carrier disk of each rotor or stator.

[0040] In one variant of the disc rotor machine, the space between or within the field coils of the rotor and / or the stator can be designed without iron.

[0041] In one variant, iron-containing covers can be provided on both end faces of the machine, designed to withstand high axial magnetic forces. These axial forces can result from, for example, 5–20 bar of magnetic axial pressure during operation. For this purpose, the iron-containing covers can be designed to be sufficiently rigid against torsional and bending forces, for example, by means of reinforcing ribs. Alternatively or additionally, one or all of the iron-containing covers can be designed for magnetic flux return. These measures reduce ohmic losses as long as no magnetic saturation effects occur.

[0042] 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 configuration, the magnetic flux return and / or the current return of an even-numbered machine can occur in the stator of an odd-numbered machine. In other words, in an arrangement of two or more machines, the current of the even-numbered machine is returned in the stator of the odd-numbered machine.

[0043] With the arrangement and operation of the landing gear revealed here, a more highly electrified aircraft than before is possible, which can be realized with a small number of parts and without the landing gear hydraulics previously required.

[0044] The design of the brake disc package and the wheel suspension of the chassis can remain unchanged compared to conventional chassis.

[0045] The mechanical force / torque generation by means of the electromechanical actuator takes place centrally on the chassis axle instead of several distributed hydraulic cylinders.

[0046] The clamping force of the brake is generated using an electric disc rotor machine described above as an electromechanical actuator.

[0047] The electric disc rotor machine of the first electromechanical actuator is rigidly coupled to the threaded drive via a sliding seat for braking operation.

[0048] By unlocking the sliding seat of the threaded drive nut, the electric disc rotor machine of the first electromechanical actuator allows fan operation.

[0049] The electric disc rotor machine is rigidly coupled to the landing gear rim for taxiing or landing operations with wheels that are already pre-accelerated, ideally to touchdown speed.

[0050] The chassis presented here makes it possible, among other things, to implement an integrated function for the brake, fan, and wheel drive. However, partial solutions such as a pure braking function are also possible.

[0051] The high dynamics of the electric disc rotor machine also allow the implementation of an anti-lock braking system for the chassis and precise brake force adjustment per wheel.

[0052] Automatic wear adjustment must also be implemented for the brake system.

[0053] In a method for operating the landing gear of an aircraft or land vehicle with an axle, a wheel carried by the axle, and a first electromechanical actuator which is 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 order to actuate or release it in a first operating mode, wherein the brake arrangement is arranged and configured to exert a braking torque on the wheel in response to actuation 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 blower arrangement acting on the brake arrangement and / or the wheel in order to actuate it.

[0054] Further features, characteristics, advantages and possible variations of this electric machine and its operation are clarified by reference to the following description, which includes the accompanying drawings.

[0055] The variants of the chassis described here, as well as its functional and operational aspects, serve only to facilitate a better understanding of its structure, operation, and properties; they do not limit the disclosure to the exemplary embodiments shown. The figures are partly schematic, with essential properties and effects sometimes significantly enlarged to illustrate the functions, operating principles, technical designs, and features. Each operating principle, each technical design, and each 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 operating principles, technical designs, and features contained in or arising from this disclosure, so that all conceivable combinations can be attributed to the described devices.This includes combinations of all individual embodiments in the text, that is, in every section of the description, in the claims, and also combinations of different variants in the text, in the claims, and in the figures, and these can be the subject of further claims. The claims do not limit the disclosure and thus the possible combinations of all the features shown. All disclosed features are explicitly disclosed here, both individually and in combination with all other features. Brief description of the characters Fig. Figure 1 shows a chassis in a schematic side view. The Fig. Figures 2-4 show the chassis in a schematic side view with a variant of the first electro-mechanical actuator and the gearbox arrangement in different operating modes M1-M3. Detailed description of chassis variants and their operation

[0056] Fig. Figure 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, which comprises a rim 104a and a tire 104b. A first electromechanical actuator 110 is associated with the landing gear 100. The actuator is connected on its output side 112 to an input side 132 of a gearbox assembly 130. The gearbox assembly 130 is switchable between at least two, and in the present variant between three, operating modes M1, M2, and M3.

[0057] The transmission assembly 130, controlled by a control unit CU, is to be brought into a first operating mode M1. In the first operating mode M1, the transmission assembly 130 couples the first electromechanical actuator 110 with a brake assembly 106 of the chassis 100 in order to actuate or release this brake assembly 106. The brake assembly 106 serves to exert a braking torque on the wheel 104 in response to actuation of the brake assembly 106 by the first electromechanical actuator 110.

[0058] The gear assembly 130, controlled by the control unit CU, is to be brought into a second operating mode M2. In this second operating mode M2, the gear assembly 130 couples the first electromechanical actuator 110 with the wheel 104, more precisely with the rim 104a of the wheel 104, in order to set the wheel 104 into rotation by means of the electromechanical actuator 110.

[0059] The gearbox assembly 130, controlled by the control unit CU, is to be brought into a third operating mode M3. In this third operating mode M3, the gearbox assembly 130 couples the electromechanical actuator 110 with a blower assembly 120, which is then actuated by the first electromechanical actuator 110. In one variant, the blower assembly 120 is aerodynamically designed to assist the wheel drive, particularly during landing approach. The blower assembly 120 comprises a ring of fan blades. This ring of fan blades is directed towards the brake assembly 106 and / or the wheel 104 and / or the control unit CU and / or the electromechanical actuator 110 to cool them.

[0060] In the Fig. Figure 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 electric machine in the form of a disc rotor machine. This disc rotor machine has a circular rotor 114 in plan view and a corresponding circular stator 116 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, which are not shown in detail here, rotor field coils take the place of the permanent magnets 114a of the rotor 114.

[0061] The rotor 114 and the stator 116, more precisely their respective support disks 114', 116', each have an end face 1141, 1142; 1161, 1162 facing each other. An air gap 118 is formed between the rotor support disk 114' and an adjacent stator support disk 116'.

[0062] 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 in the current-carrying state and / or the permanent magnets 114a generate magnetic fields of the same or opposite orientation at least temporarily, causing a rotational movement of the rotor 114 relative to the stator 116.

[0063] The disc rotor machine of the first electromechanical actuator 110 has a housing shell 116c, on the inner surfaces of which the stator 116 is formed, and which encloses the rotor 114. The housing shell contains iron and also serves as magnetic flux return. In another variant, an aluminum housing and a high-quality wound sheet metal return are provided to save weight and reduce magnetic losses.

[0064] 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 designed 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 embedded in the carrier disk 116' of each stator 116, with vias (not shown). Depending on the number of electrical phases of the machine, the conductor tracks (not shown) are circular segment-shaped spiral tracks that generate a rotating field and are embedded in or arranged on the surface(s) of the carrier disk 116' of the stator 11. The space of the stator 116 located between or within the field coils 116a is ironless.

[0065] The rotor 114 has a tubular bearing flange 114f at its center, which radially supports the rotor's carrier disk 114' and two inner bearing rings of rolling bearings 114w' and 114w'' in a captive manner. The two outer bearing rings of the rolling bearings 114w' and 114w'' are captive supported longitudinally and circumferentially on the housing shell 116c of the stator 116, allowing 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, which is bent towards the axis 102, and is displaceable longitudinally along the central longitudinal axis M on the axis 102. The support tube 116r is captive fixed longitudinally and circumferentially on the axis 102.

[0066] The gearbox assembly 130 is associated with a linear drive 136 controlled by the control unit CU. This linear drive 136 moves 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.

[0067] The bearing flange 114f has at one end (in the Fig. 2 - 4 right) a radially inwardly directed toothed ring 114z. This radially inwardly directed toothed ring 114z is engaged or disengaged with a radially outwardly directed toothed ring 138z arranged on a threaded nut 138m of a ball screw drive 138, depending on the axial positioning of the electro-mechanical actuator 110 along the axis 102.

[0068] When the two gear rings 114z and 138z are in mesh with each other, as is the case in Fig. As illustrated in Figure 3, rotation of the electromechanical actuator 110 causes a hollow spindle 138h of the ball screw drive 138, which is guided longitudinally displaceable 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 (in the Fig. 2 - 4 right) a ring-shaped thrust piston 106a, cranked away from the axis 102, which acts on a stack of brake discs 106c. The rotation of the runner 114 rotates the threaded nut 138m of the ball screw drive 138. This causes the longitudinally displaceable hollow spindle 138h of the ball screw drive 138 and with it the ring-shaped thrust piston 106a to move along the axis 102 ( Fig. 3 to the right) and thereby compresses the brake assembly 106.

[0069] The stack of brake discs 106c comprises several brake discs 106c, which are alternately attached 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 has an L-shaped cross-section. It is fixed to the axle 102 so as to be rotationally fixed and longitudinally immovable.

[0070] With the in Fig. In the position of the ball screw drive 138 and the electromechanical actuator 110 illustrated in Figure 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 actuate or release it. After coupling, when the first electromechanical actuator 110 rotates, the brake assembly 106 can apply or reduce a braking torque to the wheel 104.

[0071] To enter the second operating mode M2, in which the electromechanical actuator 110 couples with the wheel 104, the electromechanical actuator 110 is moved by the linear drive 136 towards the rim 104a (in Fig. 4 to the far right), that at the end (in Fig. 4 (to the far right) of the tubular bearing flange 114f, a drive ring 114r with pin 114s engages in oppositely shaped openings 104o in the rim of the wheel 104. In this position, the two gear rings 114z and 138z must no longer be engaged. This realizes a second operating mode M2, in which the electromechanical actuator 110 is pushed towards the wheel 104 by the linear drive 136, so that the electromechanical actuator 110 couples to the wheel 104 in a rotationally fixed manner. In this position, rotation of the electromechanical actuator 110 causes the wheel 104 to rotate about the axis 102.

[0072] Between the housing shell 116c and the wheel 104, the tubular bearing flange 114f carries a blower assembly 120. When the first electromechanical actuator 110 rotates, the blower assembly 120 rotates with it. In the Fig.In the variant shown in Figure 2b, the blower assembly 120 is permanently and rigidly coupled to the tubular bearing flange 114f. In other variants, the blower assembly 120 can be switched between being rigidly coupled and uncoupled with the rotor 114a of the first electromechanical actuator 110. All these variants enable the third operating mode M3, in which the first electromechanical actuator 110 is coupled, or can be coupled, to the blower assembly 120 acting on the brake assembly 106 and / or the wheel 104 in order to actuate the blower assembly 120.

Claims

[1] Landing gear (100) of an aircraft or land vehicle with - one axis (102); - a wheel (104) carried by the axle (102); - an electromechanical actuator (110) which is connected on the output side (112) to an input side (132) of a gear arrangement (130); wherein - the transmission arrangement (130) is switchable between at least two operating modes (M1, M2, M3) and is designed to do so, (i) in a first operating mode (M1) to couple the electromechanical actuator (110) with a brake assembly (106) in order to actuate or release it, the brake assembly (106) being arranged and configured to exert a braking torque on the wheel (104) in response to actuation of the brake assembly (106); and / or (ii) in a second operating mode (M2) to couple the electromechanical actuator (110) with the wheel (104) in order to rotate the wheel (104); and / or (iii) in a third operating mode (M3) to couple the electro-mechanical actuator (110) with a blower assembly (120) acting on the brake assembly (106) and / or the wheel (104) in order to actuate them. [2] Landing gear (100) of an aircraft or land vehicle according to claim 1, wherein - the electromechanical actuator (110) (i) to apply a braking torque to the wheel (104), and / or (ii) to rotate the wheel (104), and / or (iii) comprising an electric disc rotor machine for operating the blower arrangement (120), with at least one rotor (114a) and at least one stator (124); - which at least one runner (114a) and at least one upright (124) each have an end face facing each other (114aa, 114ab; 124a, 124b); - the at least one rotor (114a) and / or the at least one stator (124) each have an ironless carrier disk (114a', 124') which each carry field coils (126a) or permanent magnets (114a); an air gap (128) is formed between the carrier disk (114a') of each rotor (114a) and the carrier disk (124') of each stator (124); - the field coils (126) and / or the permanent magnets (114a) are aligned and arranged on the carrier disk (114a') of each rotor (114a) or the carrier disk (124') of each stator (124) such that the field coils (126) in the current-carrying state and / or the permanent magnets (114a) generate magnetic fields of the same or opposite orientation at least temporarily, 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 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) as a ferromagnetic carrier disk, and the field coils (126) have multi-phase conductor tracks embedded in or at least partially exposed in the carrier disk (114a'; 124') of each rotor (114a) or each stator (124), possibly with vias. [4] Landing gear (100) of an aircraft or land vehicle according to claim 2 or 3, wherein - permanent magnets (114a) are provided embedded or at least partially exposed in the carrier disk of each rotor (114a) or stator (124), which are approximately 0.5 to 15 times, preferably four to twelve times, as high as the air gap in the axial direction (128); - 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 field coils (126) designed for three or higher phases; and / or - a control unit (CU) is provided which is set up and connected to the field coils (126) in such a way that the field coils (126) of one of the carrier disks (124') of each stator (124) can be controlled synchronously independently of the field coils (126) of another carrier disk (124') of the stator (124). [5] Landing gear (100) of an aircraft or land vehicle 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 rotor support disc and each stator support disc are arranged to be movable relative to each other in the axial direction of the machine shaft; and / or The space between or within the field coils (116a) of the rotor (14) and / or the stator (16) is ironless; and / or Ferrous coverings are provided on both end faces of the machine, which (i) are designed to withstand high axial magnetic forces, and / or (ii) are designed for magnetic flux recirculation. [6] Landing gear (100) of an aircraft or land vehicle according to any one of claims 1 to 5, wherein - the gearbox arrangement (130) for (i) the first mode (M1) is configured, after coupling the electromechanical actuator (110) to the brake assembly (106), to convert a rotary motion performed by the electromechanical actuator (110) into a linear motion by means of a trapezoidal, ball, or planetary screw drive in order to actuate or release the brake assembly (106); and / or - the gearbox arrangement (130) for (ii) the second mode (M2) is configured, after coupling the electromechanical actuator (110) with the wheel (104), to convert a rotary motion performed by the electromechanical actuator (110) into a rotary motion of the wheel (104); and / or - the gearbox arrangement (130) for (iii) the third mode (M3) is configured, after coupling the electro-mechanical actuator (110) with the blower assembly (120), to convert a rotary movement performed by the electro-mechanical actuator (110) into a rotary movement of the blower assembly (120). [7] Landing gear (100) of an aircraft or land vehicle according to any one of claims 1 to 6, wherein - the gear arrangement (130) includes a second actuator (150) which is configured to the runner (114a) of the electro-mechanical actuator (110) (i) for the first mode (M1) to couple in a rotationally fixed manner with a trapezoidal, spherical, or planetary threaded nut () of the trapezoidal, spherical, or planetary threaded drive in order to convert the rotary motion performed by the electro-mechanical actuator (110) into a linear motion of a threaded spindle () in order to actuate or release a brake shoe of the brake assembly (106); the rotor (114a) of the electro-mechanical actuator (110) (ii) to couple the wheel (104) in a rotationally fixed manner for the second mode (M2) in order to convert the rotary motion performed by the electro-mechanical actuator (110) into a rotary motion of the wheel (104); the rotor (114a) of the electro-mechanical actuator (110) (iii) for the third mode (M3) to decouple from the trapezoidal, spherical, or planetary threaded nut () of the trapezoidal, spherical, or planetary threaded drive and from the wheel (104) in order to actuate the blower assembly (120) acting on the brake assembly (106) and / or the wheel (104) in a rotating manner; wherein - the blower arrangement (120) is optionally permanently coupled or switchable between permanently coupled and uncoupled to the rotor (114a) of the electro-mechanical actuator (110). [8] Method for operating a landing gear (100) of an aircraft or land vehicle comprising an axle (102); a wheel (104) carried by the axle (102); and an electromechanical actuator (110) which is connected on the output side (112) to an input side (132) of a transmission arrangement (130); wherein - the transmission arrangement (130) is switched between at least two operating modes (M1, M2, M3) in order to (i) in a first operating mode (M1) to couple the electromechanical actuator (110) with a brake assembly (106) in order to actuate or release it, the brake assembly (106) being arranged and configured to exert a braking torque on the wheel (104) in response to actuation of the brake assembly (106); and / or (ii) in a second operating mode (M2) to couple the electromechanical actuator (110) with the wheel (104) in order to rotate the wheel (104); and / or (iii) in a third operating mode (M3) to couple the electro-mechanical actuator (110) with a blower assembly (120) acting on the brake assembly (106) and / or the wheel (104) in order to actuate them.

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