Actuator and aircraft

Abstract

The present invention relates to an actuator with a housing, a piston that can be extended at least partially from the housing and a locking unit, wherein the locking unit has locking means that can be arranged to lock the piston in one, two or more piston positions on the housing, wherein the locking unit has unlocking means that are designed to arrange the locking means in such a way that the locking of the piston on the housing is unlocked.

Description

[0001] The present invention relates to an actuator comprising a housing, a piston which can be at least partially extended from the housing, and a locking unit, wherein the locking unit has locking means which can be arranged in such a way as to lock the piston in one, two or more piston positions on the housing.

[0002] In addition to the still widely used hydraulic actuators, it is known to use an electromechanical actuator (EMA), comprising a motor, gearbox and spindle, to actuate landing gear for aircraft.

[0003] Such EMAs are also increasingly being used for aircraft without central hydraulics, e.g. drones and air taxis.

[0004] It is known to lock such EMAs in certain positions using balls.

[0005] A disadvantage of known locking devices from the state of the art is that the unlocking of the locking device, for example for a free fall of the landing gear, is triggered by complicated mechanisms and brought back into the unlocking position or that it is not possible to unlock the locking device for a free fall of the landing gear at all.

[0006] Against this background, the object of the present invention is to provide an actuator which is improved compared to an actuator mentioned above and which in particular provides an automatic locking mechanism for locking a position of the actuator and an automatic unlocking of the locking mechanism.

[0007] This object is achieved by the subject matter having the features of independent claim 1. Advantageous developments of the invention are the subject matter of the dependent claims.

[0008] Accordingly, the invention provides that the locking unit has unlocking means which are designed to arrange the locking means in such a way that the locking of the piston on the housing is unlocked.

[0009] The piston can particularly preferably be locked by the locking unit in its fully or almost fully retracted and / or extended end position.

[0010] For the purposes of this invention, "locking" is preferably understood to mean that a blocking or fixing of an element, e.g., the piston, that is movable relative to another element, e.g., the housing, occurs, so that the movable element can no longer be moved, or can only be moved slightly, relative to the other element by external forces acting on the actuator. For the purposes of this invention, "unlocking" is preferably understood to mean that a blocking or fixing of an element, e.g., the piston, that is movable relative to another element, e.g., the housing, is removed.

[0011] Preferably, it is provided that the housing has a housing opening, in particular in the form of an elongated hole, and the locking unit has a locking unit opening, in particular in the form of an elongated hole, and the locking means have a clamping element and a blocking element, wherein the clamping element can be arranged in a first clamping element position, in which the clamping element is arranged at least partially in the housing opening and at least partially in the locking unit opening, and the blocking element can be arranged in a first blocking element position, in which the blocking element holds the clamping element in the first clamping element position, whereby the piston is locked to the housing in a piston position, wherein the clamping element can be arranged in a second clamping element position, in which the clamping element is not arranged in the housing opening and / or not in the locking unit opening, and the blocking element in a second blocking element position,in which the locking element does not hold the clamping element in the first clamping element position, whereby the piston is not locked in a piston position on the housing and / or the locking of the piston on the housing is unlocked.

[0012] The locking unit opening can also be a piston opening.

[0013] It is preferably provided that the clamping element has a spherical or wedge shape and / or the locking unit has more than one clamping element and / or the blocking element is or has a slider, which preferably has a contour with a ramp and / or the locking unit has more than one blocking element.

[0014] Preferably, the locking unit comprises locking means comprising balls, a contoured slide, and springs. When the actuator and / or piston are locked, the balls preferably remain with the ball center within a joint between the housing and the piston and / or the locking unit, so that they automatically release from the first clamping element position or from the clamping position upon release.

[0015] The locking unit particularly preferably has a plurality of balls and in particular no differently shaped clamping elements.

[0016] Preferably, the clamping element and / or the locking unit are controlled by the spindle position. The locking unit is preferably controlled by the spindle.

[0017] The locking unit preferably locks or blocks automatically upon reaching the end positions of the piston or actuator, even in a free-fall mode of the actuator. A free-fall mode of the actuator is preferably a state of the actuator in which the piston moves from a fully or partially extended position toward its extended end position only by pulling on the piston, e.g., by the gravity of the chassis on which the actuator is mounted.

[0018] It is preferably provided that the locking element can be arranged in the first locking element position by means of a locking element spring and / or that the locking element can be arranged in the second locking element position by means of the unlocking means.

[0019] The unlocking means can preferably be actuated by an electrical trigger. The unlocking means preferably enable a free-fall mode for the actuator. Enabling a free-fall mode is particularly advantageous for the use of the actuator in a drone or an autonomous air taxi.

[0020] It is preferably provided that the unlocking means comprise an unlocking element and / or an unlocking unit that can be moved by means of a spindle nut.

[0021] It is preferably provided that the unlocking unit has an unlocking piece and an unlocking actuator which is designed to arrange the unlocking piece in an unlocking position in which the unlocking piece arranges the locking means such that the locking of the piston on the housing is or will be unlocked, and the unlocking piece can be arranged in a locking position in which the locking of the piston on the housing is not unlocked by the unlocking piece.

[0022] It is preferably provided that the unlocking actuator has an unlocking spring and the unlocking piece can be arranged in the unlocking position by means of the unlocking spring and / or the unlocking actuator has holding means, which preferably have a holding ball, which can be arranged in a holding position in which the holding means hold the unlocking piece, which preferably has a groove for receiving the holding ball, in the locking position against a force of the unlocking spring.

[0023] It is preferably provided that the unlocking actuator has an electromagnet, an unlocking actuator spring and a magnet armature piston, wherein the magnet armature piston can be arranged in a first magnet armature piston position by means of the unlocking actuator spring, in which first magnet armature piston position the magnet armature piston arranges the holding means in the holding position and / or wherein the magnet armature piston can be arranged by the electromagnet against a force of the unlocking actuator spring in a second magnet armature piston position, in which second magnet armature piston position the holding means can be arranged in a release position in which the unlocking piece is not held in the locking position by the holding means and / or in which the unlocking piece can be arranged in the unlocked position by means of the unlocking spring.

[0024] It is preferably provided that the unlocking piece can be arranged in the locking position by means of a reset element, in particular arranged on a spindle nut.

[0025] Preferably, the actuator is in a free-fall mode when the release piece has been or is placed in an unlocked position. Resetting the free-fall mode is preferably enabled by springs and elongated holes on the piston and / or the housing. The reset element can be moved by the locking element, which is preloaded by the locking element spring, and the housing opening and / or the locking unit opening, each in the form of elongated holes, such that the release piece can be placed in the locked position.

[0026] The free-fall mode is preferably triggered by the release unit. The release unit is preferably arranged on the side of the piston's retraction direction. The actuator is preferably placed in free-fall mode by moving the release unit and / or the release piece into the unlocked position.

[0027] Preferably, the actuator is simply reset after the spindle activates free-fall mode. This eliminates the need for service and / or repair of the actuator after the actuator has entered free-fall mode. Preferably, the actuator's free-fall mode can be tested repeatedly.

[0028] It is preferably provided that the actuator has an electromechanical drive, in particular an electric motor and / or a gear for driving a spindle.

[0029] The actuator is preferably intended for operating the landing gear of an aircraft.

[0030] The invention also relates to a method for operating an actuator according to the invention, wherein the actuator is placed into a free-fall mode by actuating, in particular electromechanically, an unlocking unit.

[0031] Preferably, the free-fall mode of the actuator is reset by actuating an unlocking unit, in particular by moving a reset element. After the reset, the actuator is preferably no longer in free-fall mode.

[0032] The characteristics of the actuator are preferably, mutatis mutandis, also characteristics of the method.

[0033] In other words, it is preferably provided that the actuator has a lockable spindle drive, e.g. a ball screw drive, with a spindle and a piston driven by the spindle drive, in which a locking of the two end positions of the actuator and / or the piston is provided by a locking unit, wherein the locking can be unlocked by the spindle or a movement of the spindle and in which the locking can additionally be unlocked by an unlocking unit, comprising a small actuating magnet, wherein the unlocking unit has a spring-biased unlocking mechanism which can be reset by the spindle and / or by a reset element.

[0034] The actuator preferably has a mechanical locking unit with electromechanical emergency release and automatic release by the movement of the spindle.

[0035] The invention also relates to an aircraft, in particular an airplane or drone, with an actuator according to the invention.

[0036] It should be noted here that the terms "a" and "an" do not necessarily refer to exactly one of the elements, although this represents a possible embodiment, but can also refer to a plurality of the elements. Likewise, the use of the plural also includes the presence of the element in question in the singular, and conversely, the singular also encompasses several of the elements in question. Furthermore, all features of the invention described herein can be combined with one another as desired or claimed in isolation from one another.

[0037] Further advantages, features, and effects of the present invention will become apparent from the following description of preferred embodiments with reference to the figures, in which identical or similar components are designated by the same reference numerals. Herein: Fig. 1: a sectional view of an embodiment of an actuator according to the invention. Fig. 2: a detail of the sectional view of the embodiment of an actuator according to the invention from Fig. 1. Fig. 3: two sectional views of a trigger mechanism of an embodiment of an actuator according to the invention. Fig. 4: two sectional views of a trigger mechanism of an embodiment of an actuator according to the invention.

[0038] In Fig. 1 shows an actuator comprising an electric motor 1, a gear 2, a spindle 3, a piston 4, a locking unit 5, a trigger unit 6 and two position sensors 7.

[0039] In particular, the spindle 3, the piston 4, and the locking unit 5 are at least partially enclosed by a housing 8. A spring assembly 9, in particular comprising disc springs, is arranged in the housing.

[0040] The locking unit 5 is connected to the piston 4 and can include areas of the piston 4.

[0041] The actuator is driven by an electric motor 1 and / or is an EMA.

[0042] Gear 2 is preferably a single- or multi-stage planetary gear. Gear 2 can also be a spur or bevel gear, or a combination of the two.

[0043] The spindle 3 is preferably a ball screw. The spindle 3 can also be a trapezoidal thread spindle, planetary screw, etc.

[0044] The locking unit 5 has two locking elements in the form of, in particular, sleeve-shaped, slides 51, at least two clamping elements 53 and two locking element springs 52. The arrangement of the clamping elements 53, the slides 51 and springs 52 in the locking unit 5 is shown in Fig. 2. Several clamping elements 53 can also be provided per locking element. The clamping elements 53 can be arranged around the locking element, in particular at equal intervals.

[0045] In this embodiment, the clamping elements 53 are balls.

[0046] A locking element spring 52 is fixedly arranged at one end, for example, on a shoulder in the locking unit 5 and presses a slider 51 against a clamping element 53.

[0047] The slider 51 has a contour with a ramp, whereby the slider presses the clamping element 53 in the direction of the housing 8 when the clamping element 53 is arranged on the ramp.

[0048] The locking unit 5 has a plurality of locking unit openings and the housing 8 has one or more housing openings 41.

[0049] If the clamping element 53 is in a suitable position relative to a housing opening 41 of the housing 8, the slide 51 pushes the clamping element 53 into the housing opening 41 of the housing 8. The slide 51 is moved further by means of the locking element spring 52 and is arranged in an end position of the slide 51 with a surface of the slide 51 under the clamping element 53, whereby a movement of the clamping element 53 out of the housing opening 41 of the housing 8 is prevented.

[0050] The locking unit 5 has a locking unit opening in which the clamping element is also at least partially arranged. Part of the piston 4 can be part of the locking unit 5. The locking unit opening can thus be a piston opening.

[0051] The clamping element 53 thus locks the locking unit 5 to the housing 8 by being arranged in a joint between a locking unit opening of the locking unit 5 and a housing opening 41 of the housing 8. The locking unit 5 and the elements connected thereto, such as the piston 4, are thus no longer movable or only slightly movable relative to the housing 8.

[0052] Several clamping elements 53 can also be pushed by the slider 51 into corresponding housing openings 41 of the housing 8.

[0053] To release the locking of the locking unit 5, the slide 51 is moved from its end position.

[0054] The movement of the slide 51 from its end position can be effected by the spindle 3. An element of the spindle 3, such as a spindle nut of the spindle 3, preferably rests against the slide 51 after several revolutions of the spindle 3 and moves it out of the end position by means of a release element, e.g., a surface or a shoulder of the spindle nut, upon further revolutions of the spindle 3. The movement of the slide 51 occurs against the force of the locking element spring 52.

[0055] When the slider 51 is moved by the unlocking element so far from its end position in which it blocks the movement of the clamping element 53, the slider 51 releases the clamping element 53 so that it moves completely out of the housing opening 41 of the housing 8.

[0056] Upon corresponding movement of the locking unit 5, the clamping elements 53 are preferably pressed out of the housing opening 41 of the housing 8 through a region or a locking unit opening of the locking unit 5.

[0057] The center of the disengaged clamping element 53 in the form of a ball is preferably arranged within a parting line between a locking unit opening of the locking unit 5 and a housing opening 41 of the housing 8 so that the clamping element 53 can be pressed out of the housing opening 41 of the housing 8.

[0058] The clamping element 53 can also be wedge-shaped and / or a wedge.

[0059] The locking unit opening and / or the housing opening 41 can be designed as a circumferential groove, bore or elongated hole and / or can be adapted to the shape of the clamping element 53.

[0060] In order to be able to extend the piston 4 from the actuator without actuation by the electric motor 1, as is the case, for example, when the actuator is used in a chassis in free fall, i.e. in a free fall mode, the locking unit 5 can be unlocked by an unlocking unit 6, in particular an electromechanical one.

[0061] In the left figure of Fig. 3, the unlocking unit 6 is shown in a locked state. In the right figure of Fig. 3, the unlocking unit 6 is shown in an unlocked state.

[0062] The unlocking unit 6 has an electromagnet 61 in which a magnet armature piston 63 is held in a rest position by an unlocking actuator spring 62, as can be seen from Fig. 3.

[0063] Around the magnet armature piston 63, an unlocking actuator housing 64 is arranged with one or more bores in which one or more holding means in the form of holding balls 65 are arranged, as can be further seen from Fig. 3.

[0064] Preferably, a retaining ball 65 is arranged at least partially in a bore of the unlocking actuator housing 64. Preferably, another retaining ball 65 is arranged in a further bore of the unlocking actuator housing 64. The unlocking unit 6 preferably has two retaining balls 65.

[0065] The retaining balls 65 are each pressed out of the unlocking actuator housing 64 by an edge on the magnet armature piston 63, preferably halfway, so that the retaining balls 63, with the pressed-out part, hold a part of an unlocking piece in the form of a fork piece 66, as can be seen from the upper illustration of Fig. 4.

[0066] In the upper image of Fig. 4, the release piece is in a locking position, the holding balls 65 are in a holding position and the magnet armature piston 63 is in a first magnet armature piston position.

[0067] The release piece preferably comprises the fork piece 66 and an ejector 68 connected to the fork piece 66.

[0068] When the electromagnet 61 is actuated and / or energized, the armature piston 63 is attracted by the electromagnet 61 against the force of the release actuator spring 62. In the process, the edge of the armature piston 63 is also retracted so that the retaining balls 65 are completely accommodated in the release actuator housing 64.

[0069] As a result, the fork piece 66, which is held in place by the retaining balls 65 in the resting state and pre-tensioned by the release spring 67, is released.

[0070] The release spring 67 relaxes, the release piece moves into an unlocked position by the release spring 67 and the ejector 68 moves the slide 51 of the locking unit 5 from an end position or from its first locking element position.

[0071] In the figure below from Fig. 4, the release piece is in an unlocking position, the retaining balls 65 are in a release position and the armature piston 63 is in a second armature piston position.

[0072] The force of the release spring 67 is preferably greater than the force of the locking element spring 52. Preferably, several release pieces with spring-loaded ejectors 68 can be actuated by an electromagnet 61.

[0073] When the electromagnet 61 is de-energized, the armature piston 63 is pushed back by the release actuator spring 62. This pushes the retaining balls 65 out of the release actuator housing 64.

[0074] The unlocking unit 6 can be reset using the spindle 3.

[0075] After the piston 4 has been extended, the spindle 3 can actively retract the piston 4 again using the electric motor 1. To also reset the release unit 6, the spindle 3 moves a little further. This is made possible by the housing openings 41 and / or the locking unit openings being designed as elongated holes. This retensions the release spring 67. The retaining balls 65 are pushed out of the openings again by the release actuator spring 62 as soon as the fork piece 66, with its openings, once again frees up space for the retaining balls 65.

[0076] Since the housing openings 41 and / or the locking unit openings for resettability are preferably designed as elongated holes, the locking unit 5 has a play of, for example, a few mm.

[0077] The play of the locking unit 5 can be compensated by a spring assembly 9 on one or both sides between the locking unit 5 and / or piston 4 and housing 8 and / or in the chassis kinematics (not shown).

[0078] The invention preferably has the following advantages: - The locking unit automatically locks or blocks when one of the two end positions is reached; - The state of free fall, i.e. the free fall mode, can be triggered electrically; - The release unit can be reset by the spindle without the need to service the actuator or the release unit; - When locked, the spindle is so far away from the locking unit that the lock cannot be unlocked by vibration alone. - To unlock the locking unit, several revolutions of the spindle are preferably required and the force of a locking element spring 52 must preferably be overcome.

Claims

[1] Actuator with a housing, a piston which can be at least partially extended from the housing and a locking unit, wherein the locking unit has locking means which can be arranged in such a way as to lock the piston in one, two or more piston positions on the housing, wherein the locking unit has unlocking means which are designed to arrange the locking means in such a way that the locking of the piston on the housing is unlocked, characterized by that the unlocking means comprise an unlocking element movable by means of a spindle nut. [2] Actuator according to claim 1, characterized bythat the housing has a housing opening, in particular in the form of an elongated hole, and the locking unit has a locking unit opening, in particular in the form of an elongated hole, and the locking means have a clamping element and a blocking element, wherein the clamping element can be arranged in a first clamping element position, in which the clamping element is arranged at least partially in the housing opening and at least partially in the locking unit opening, and the blocking element can be arranged in a first blocking element position, in which the blocking element holds the clamping element in the first clamping element position, whereby the piston is locked to the housing in a piston position, wherein the clamping element can be arranged in a second clamping element position, in which the clamping element is not arranged in the housing opening and / or not in the locking unit opening, and the blocking element can be arranged in a second blocking element position,in which the locking element does not hold the clamping element in the first clamping element position, whereby the piston is not locked in a piston position on the housing and / or the locking of the piston on the housing is unlocked. [3] Actuator according to claim 2, characterized by that the clamping element has a spherical or wedge shape and / or the locking unit has more than one clamping element and / or the blocking element is or has a slider, which preferably has a contour with a ramp and / or the locking unit has more than one blocking element. [4] Actuator according to one of claims 2 or 3, characterized by that the locking element can be arranged in the first locking element position by means of a locking element spring and / or that the locking element can be arranged in the second locking element position by means of the unlocking means. [5] Actuator according to one of the preceding claims, characterized bythat the unlocking means comprise an unlocking unit. [6] Actuator according to claim 5, characterized by that the unlocking unit has an unlocking piece and an unlocking actuator which is designed to arrange the unlocking piece in an unlocking position in which the unlocking piece arranges the locking means such that the locking of the piston on the housing is or becomes unlocked, and the unlocking piece can be arranged in a locking position in which the locking of the piston on the housing is not unlocked by the unlocking piece. [7] Actuator according to claim 6, characterized bythat the unlocking actuator has an unlocking spring and the unlocking piece can be arranged in the unlocking position by means of the unlocking spring and / or the unlocking actuator has holding means which preferably have a holding ball which can be arranged in a holding position in which the holding means hold the unlocking piece, which preferably has a groove for receiving the holding ball, in the locking position against a force of the unlocking spring. [8] Actuator according to claim 7, characterized byin that the unlocking actuator has an electromagnet, an unlocking actuator spring and a magnet armature piston, wherein the magnet armature piston can be arranged in a first magnet armature piston position by means of the unlocking actuator spring, in which first magnet armature piston position the magnet armature piston arranges the holding means in the holding position and / or wherein the magnet armature piston can be arranged by the electromagnet against a force of the unlocking actuator spring in a second magnet armature piston position, in which second magnet armature piston position the holding means can be arranged in a release position in which the unlocking piece is not held in the locking position by the holding means and / or in which the unlocking piece can be arranged in the unlocked position by means of the unlocking spring. [9] Actuator according to one of claims 6 to 8, characterized by that the unlocking piece can be arranged in the locking position by means of a reset element, in particular arranged on a spindle nut. [10] Actuator according to one of the preceding claims, characterized by that the actuator has an electromechanical drive, in particular an electric motor and / or a gear for driving a spindle. [11] Aircraft, in particular an airplane or drone, with an actuator according to one of the preceding claims. [12] Method for operating an actuator according to one of claims 1 to 10, characterized by that the actuator is put into a free-fall mode by actuating, in particular electromechanically, an unlocking unit. [13] Method according to claim 12, characterized by that the free fall mode of the actuator is reset by actuating an unlocking unit, in particular by moving a reset element.

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