Reverse brake for an aircraft

Abstract

Return brake for at least one control surface of an aircraft, comprising a spring arrangement (2), a ball ramp mechanism (5) and at least one coupling mechanism (4) for coupling a drive side with an output side of the return brake, wherein exactly one constant brake (6a, 6b) activated by means of the spring arrangement is provided, characterized in that the spring arrangement (2) is arranged between two parts (5a, 6b) of the ball ramp mechanism (5), between which a plurality of balls of the ball ramp mechanism (5) are also arranged.

Description

[0001] The invention relates to a return brake for at least one control surface of an aircraft. The return brake comprises at least one spring assembly, at least one ball ramp mechanism, and at least one coupling mechanism for coupling a drive side with an output side of the return brake.

[0002] The invention further relates to an actuator for adjusting at least one control surface of an aircraft with at least one corresponding return brake, and to an aircraft, in particular an aircraft with at least one such return brake or with at least one such actuator.

[0003] Corresponding return brakes are used in a large number of aircraft to hold one or more devices or control surfaces of the aircraft in their current position in the event of a fault, e.g. after a break in a shaft system or after a failure of a drive system or actuator.

[0004] Such systems are used, for example, in connection with landing flap drives or in drives for trim actuators. However, it is conceivable to use them in connection with any control surfaces or actuators of an aircraft.

[0005] Reverse brakes of this type are mechanical reverse brakes for rotary motion. They are located between an actuator and a control surface of an aircraft that is moved by the actuator. Reverse brakes allow drive energy to be transferred from the actuator to the control surface, while preventing or minimizing reverse movements from the control surface to the actuator. US Patent 8,511,441 B2 serves as an example. Reverse brakes of this type are designed to function dynamically. This means that, at operating speed, the reverse brake, or no-back brake, can dissipate all or nearly all of the energy introduced into the reverse brake from one of its output sides, converting it into heat.

[0006] In such a dynamic operating situation, an undesirable rattling or "chatter" of the brake can often occur, which manifests itself on the one hand as a loud noise and on the other hand as torque peaks in the system or in the return brake.

[0007] From EP 2 436 952 A2, a load limiter is known which consists of the following components: a first disk for transmitting a first torque from an input and with a first ramp; a second disk for transmitting a second torque from an output and with a second ramp; a torque transmitter arranged between the first disk and the second disk within the first ramp and the second ramp; a first conical braking surface; and a second conical braking surface on one of the first disks or the second disk for interacting with the first conical surface when one or more of the first torques or the second torques cause a relative rotation between the first disk and the second disk.

[0008] US 9,616,990 B2 discloses a rotary device comprising an input shaft coupled to a torque-generating device, an output shaft, and a rotary device arranged to transmit a first torque from the input shaft to the output shaft, and equipped with a backstop to prevent a second torque applied to the output shaft from being transmitted to the input shaft if the second torque exceeds a torque limiting threshold, and with a torsion lock to prevent overloading of the torque-generating device if the second torque exceeds the torque limiting threshold.

[0009] In light of the aforementioned problem of rattling, the object of the invention is to provide an improved reverse brake in which, in particular, rattling is reduced or eliminated. This should enable smoother operation of the aircraft.

[0010] This problem is solved according to the invention by a backstop brake having the features of claim 1. Further advantageous embodiments are the subject of the dependent claims.

[0011] Accordingly, a return brake is provided for at least one control surface of an aircraft, comprising at least one spring arrangement, at least one ball ramp mechanism and at least one coupling mechanism for coupling a drive side with an output side of the return brake.

[0012] According to the invention, exactly one constant brake is provided, which is activated by the spring arrangement. The constant brake assumes the function of the main brake of the return brake. The constant brake consists of two radially spaced and, in particular, one-piece sections, with the inner section being mounted in the outer section. Since the previously conventional two axially spaced brakes are eliminated according to the invention, the detrimental rattling between them can no longer occur.

[0013] In a preferred embodiment of the invention, it is conceivable that exactly one spring arrangement and / or exactly one ball ramp mechanism are provided and / or that the constant brake is designed as a conical brake. The spring arrangement in this case relates to an arrangement acting on the ball ramp mechanism or an arrangement tensioning or applying a force to the ball ramp mechanism.

[0014] The coupling mechanism can be designed to couple the drive side with the output side of the return brake via, for example, a part of the ball ramp mechanism. The ball ramp mechanism can also be designed as part of the coupling mechanism.

[0015] According to the invention, the spring arrangement is provided that it is arranged between two parts of the ball ramp mechanism, between which a plurality of balls of the ball ramp mechanism are also arranged.

[0016] In this respect, the spring assembly is located within the ball ramp mechanism.

[0017] Furthermore, the spring assembly can be designed to exert a force on both the ball ramp mechanism and the constant brake. For this purpose, part of the ball ramp mechanism can simultaneously be part of the constant brake.

[0018] According to the invention, the spring assembly is arranged between two parts of the ball ramp mechanism, between which a plurality of balls of the ball ramp mechanism are also arranged. By appropriately positioning the spring assembly, damping between the parts of the ball ramp mechanism can be achieved by means of the spring, thereby reducing rattling. Simultaneously, the spring or spring assembly can exert a force on the constant brake.

[0019] In a further preferred embodiment of the invention, it is conceivable that the balls are arranged between the spring assembly and an outer part of the constant brake. The balls can thus be arranged radially between the spring assembly and the outer part of the constant brake. The balls do not need to be in direct contact with the outer part of the constant brake.

[0020] In another preferred embodiment, it is conceivable that the balls are spaced radially outwards from the spring assembly. It is also conceivable that there is no axial offset between the balls and the spring assembly, meaning that the spring assembly is arranged further inwards in the radial direction than the balls.

[0021] In a further preferred embodiment of the invention, it is conceivable that the ball ramp mechanism comprises, in particular, cylindrical recesses for receiving the spring assembly. It is conceivable that the recesses extend substantially the same distance in the axial direction on each of the two mutually movable parts of the ball ramp mechanism.

[0022] In another preferred embodiment, it is conceivable that the coupling mechanism or parts of the coupling mechanism are arranged within the spring assembly and the ball ramp mechanism.

[0023] In particular, it is conceivable that the spring arrangement is located within the ball ramp mechanism and the coupling mechanism or parts of the coupling mechanism are located within the spring arrangement.

[0024] In another preferred embodiment, it is conceivable that the coupling mechanism or parts of the coupling mechanism are arranged axially centrally within the spring arrangement and the ball ramp mechanism.

[0025] The invention further relates to an actuator for adjusting at least one control surface of an aircraft, comprising at least one return brake according to one of claims 1 to 9.

[0026] Further details and advantages of the invention are explained with reference to the exemplary embodiments shown in the figures. These show: Fig. 1: A backstop brake in accordance with the state of the art; and Fig. 2: a backstop brake according to the invention.

[0027] Fig. Figure 1 shows a backstop brake known from the prior art, in which two opposing conical brakes 1a, 1b and 6a, 6b are provided. These conical brakes 1a, 1b, and 6a, 6b are offset from each other in the axial direction. In both figures, the axial direction corresponds to the horizontal direction in which the dashed line shown below also runs.

[0028] The brake 6a, 6b is constantly activated by a spring mechanism 2. In a drive operation, these two brakes 1a, 1b and 6a, 6b are synchronized with each other by the coupling mechanism 4 of a drive wheel 4a.

[0029] In a counter-load situation where the return brake is to be applied, the drive comes from a gear 3, which is connected to the brake 1b. Since in this case the activated brake 6a, 6b lags behind, the ball ramp mechanism 5 is activated. This activates the brakes 1a, 1b and 6a, 6b equally strongly, enabling a very high counter-load to be maintained.

[0030] As development tests show, the unwanted rattling is caused by an oscillation between the constant brake 6a, 6b and the main brake 1a, 1b, which is located in the Fig. Figure 1 shows that, as a result of this vibration, the wing structure or the structure of the test stands is excited in such an unfavorable way that high vibration loads occur and noise is generated that is very disturbing for the passengers of an aircraft.

[0031] According to the invention, the constant brake 6a, 6b is connected to the in Fig. The main brake 1a, 1b shown in Figure 1 is coupled in such a way that the undesired rattling between these two brakes can no longer occur. For this purpose, the function of the main brake 1a, 1b is, according to the invention, Fig. 1 transferred to the constant brake 6a, 6b, so that only one cone brake remains.

[0032] Fig. Figure 2 shows a backstop brake according to the invention, comprising a spring or spring assembly 2, a ball ramp mechanism 5 with a plurality of corresponding balls, and a coupling mechanism 4 for coupling a drive side to an output side of the backstop brake. The drive side can be located on the right and the output side on the left in the figures. According to the invention, a constant brake 6a, 6b is provided, which is activated by the spring assembly 2.

[0033] Furthermore, the spring 2 or spring assembly 2 can be positioned between the two ball ramp sections 1b and 6b to dampen any unwanted oscillations between them. Therefore, the spring 2 can no longer be positioned opposite the constant brake 6a, 6b, but can be in direct contact with it. This configuration of the spring assembly 2 provides an additional damping function.

[0034] How Fig. As can be seen from Figure 2, component 6b is part of both the cone brake 6a, 6b and the ball ramp mechanism 5. Furthermore, the spring assembly 2 is also located on and touches component 6b.

[0035] Component 6b has a radially outer frustoconical or cone-shaped section which interacts with or can be brought into contact with the second, outer component 6a of the constant brake 6a, 6b.

[0036] An adjacent area may have recesses for receiving a plurality of balls and be oriented towards a further component 5a of the ball ramp mechanism.

[0037] In an inner area of ​​component 6a, a recess, in particular cylindrical, and / or a stop 6c for receiving the spring arrangement 2 may be provided.

[0038] As from Fig. As can be seen from Figure 2, the spring assembly 2 is arranged between components 5a and 6b of the ball ramp mechanism 5. Component 6b is part of both the ball ramp mechanism 5 and the constant brake 6a, 6b.

[0039] Accordingly, the spring assembly 2 is held in place and limited by the same components of the ball ramp mechanism as the balls of the ball ramp mechanism. However, the spring assembly 2 is positioned further inwards in the radial direction than the balls. The radial direction is the direction perpendicular to the dashed longitudinal axis.

[0040] The invention also relates to an actuator for an aircraft which is equipped or coupled with a return brake as described herein.

[0041] The actuator can be designed as a modular component that includes the return brake. Alternatively, it is also conceivable to arrange the return brake at a greater distance from the actuator, and in any case between the actuator and the driven control surface.

Claims

[1] Return brake for at least one control surface of an aircraft, comprising a spring arrangement (2), a ball ramp mechanism (5) and at least one coupling mechanism (4) for coupling a drive side with an output side of the return brake, wherein exactly one constant brake (6a, 6b) activated by means of the spring arrangement is provided, characterized by , that the spring arrangement (2) is arranged between two parts (5a, 6b) of the ball ramp mechanism (5), between which a plurality of balls of the ball ramp mechanism (5) are also arranged. [2] Return brake according to claim 1, characterized by , that exactly one spring arrangement (2) and / or exactly one ball ramp mechanism (5) is provided and / or that the constant brake (6a, 6b) is designed as a cone brake is. [3] Return brake according to claim 1 or 2, characterized by , that the spring assembly (2) is arranged between two parts (5a, 6b) of the ball ramp mechanism (5). [4] Return brake according to any one of the preceding claims, characterized by , that the balls are arranged between the spring assembly (2) and an outer part (6a) of the constant brake (6a, 6b). [5] Backstop brake according to any one of the preceding claims, characterized by , that the balls are spaced radially outwards from the spring arrangement (2). [6] Backstop brake according to any one of the preceding claims, characterized by , that the ball ramp mechanism (5) in particular comprises cylindrical recesses for receiving the spring assembly (2). [7] Backstop brake according to any one of the preceding claims, characterized by , that the coupling mechanism (4) or parts of the coupling mechanism (4) are arranged within the spring assembly (2) and the ball ramp mechanism (5). [8] Backstop brake according to any one of the preceding claims, characterized by, that the coupling mechanism (4) or parts of the coupling mechanism (4) are arranged axially centrally within the spring assembly (2) and the ball ramp mechanism (5). [9] Actuator for adjusting at least one control surface of an aircraft, comprising at least one return brake according to any one of claims 1 to 8. [10] Aircraft with at least one reverse brake according to any one of claims 1 to 8 or with at least one actuator according to claim 9.

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