DE102012009149A1 - Bidirectional operable rotational lock for tie rod of braking system to actuate horizontal tail units of airplane, has mechanical device connected with mass so that device is movable along axial direction when applying torque - Google Patents

Abstract

The lock has a mechanical device whose one end is connected with a shaft assembly (20) to form a rotational form closure and another end connected with an inertial mass such that the device is movable along an axial direction and clutch is releasable when applying large torque. The mechanical device is rotatable along a longitudinal axis of the lock and includes a shaft and a ball that is mounted in a connecting link, where acceleration of a shaft (22) of the shaft assembly causes transmission of the torque. A flywheel is firmly connected with a housing (100).

Description

The invention relates to a bidirectional rotation lock or lock for a shaft assembly with at least one shaft according to the preamble of claim 1, a brake system for a drive train or threaded spindle drives of flight controls according to claim 15 and a threaded spindle drive for the positioning of a trim tailplane according to claim 16.

In the flight control of aircraft arrangements are known to stop the rotational movements in a short time and then hold the achieved rotational position. Examples include torque limiters and locks in the drive train of slat and flapper drives and threaded spindle drives for operating trimmable horizontal stabilizers.

Usually friction brakes are used for this purpose. In order to achieve the required in aviation low weight of the lock, the highest possible coefficient of friction is required. For this purpose, locks are available in which the friction linings are dry. Due to the extreme environmental conditions in aircraft, however, it is difficult to ensure the required for the correct braking function dry atmosphere. In order to keep the influence of the environment on the coefficient of friction low, braking arrangements are alternatively realized in which the friction surfaces run in oil or grease. A disadvantage of these arrangements is the resulting low coefficient of friction, which in turn leads to a greater weight.

The systemic least weight has a barrier, that is an arrangement in which the rotational movement is terminated very quickly by establishing a positive engagement with a stationary body. A disadvantage of this design is the property that the rotational energy is not converted into heat and thus degraded, but is stored in the form of elastic deformation of affected components themselves. This leads to torsionally stiff constructions to high, to be considered in the dimensioning torque peaks.

However, in the specific case of an application in flight control, the aforementioned disadvantage is put into perspective, since comparatively torsionally flexible systems with low rotational speed are used here. In such systems, a lock can be used in an advantageous manner, since here outweigh the aforementioned advantages. A disadvantage of known locks, which are based on interlocking claws, that the arrangement in the braked state has a relatively large rotational play. This is due to the interlocking claws in that they require a correspondingly high rotational play in order to allow the collapse of the locks out of rotation.

From the DE 698 26 565 T2 a torque limiter is known which brings the drive shaft in positive engagement with the fixed housing from the rotation out. The positive connection is generated by interlocking claws. The drive shaft has a large rotational play in the braked state, which is defined primarily by a ball ramp assembly.

From the AT 409 533 B is a switchable dog clutch known, which could also be used as a lock with locked output shaft. However, this design can transmit the torque only in one direction of rotation and is almost free in the opposite direction of rotation.

Furthermore, between actuation request and complete mechanical change of state of the lock usually takes time on the order of 100 ms.

There are known applications in which this period of time is not available. One example is the threaded spindle drive for positioning a trimable tailplane. In the case of a breakage of torque transmitting components in this drive very high spins on the threaded spindle can occur as a result of aerodynamic loads, which can lead to a flight-critical adjustment of the horizontal stabilizer within 10 ms.

To avoid such a "running away" of the horizontal stabilizer, it already belongs to a solution of the prior art to equip the threaded spindle with a return friction brake, as exemplified in the US 6,109,415 A is described.

Return friction brakes, however, have the disadvantages that they require expensive maintenance on the one hand as a result of the wear of the friction brakes and on the other hand require a drive power increased by the friction power. Furthermore, ensuring the function is difficult because of the large coefficient of friction and, finally, the function can be tested only with great effort, the function test can be performed only under workshop conditions. Thus, malfunctions that are caused by real environmental conditions of the flight operation (eg icing), not recognized.

Object of the present invention is therefore to provide a rotation lock, in particular a bidirectional rotation lock, for a shaft assembly having a particularly short reaction time, which is independent of the direction of rotation, can be inserted from the rotation out and in the braked state has only a slight rotational play.

The above object is achieved by a bidirectionally acting rotation lock or lock for a shaft assembly having the features of claim 1.

According to the invention, the bidirectional rotation lock comprises a spin-sensitive mechanical device connected at one end to the shaft assembly such that a rotational mold closure is feasible and coupled to the other end with an inertial mass such that when an increased torque is applied, the clutch can be released and the mechanical device can be moved in the axial direction, so that a collapse of the lock takes place. In order to ensure a very rapid collapse of the locking arrangement with hochbeschleunigendem Rücktreibfall, the mechanical arrangement of a concomitant electrical shutdown of an electromagnet is combined, which is in communication with the mechanical device and mounted in the same housing.

Preferably, the mechanical device extends along the longitudinal axis of the barrier and has a shaft having a ball-and-slot arrangement at one end thereof. Due to the ball-and-gate arrangement, the mechanical device is coupled to the inertial mass. The ball-and-slot arrangement has at least one ball, which is rotatably mounted in a gate.

Preferably, the inertial mass is a flywheel, which has at least one ball backdrop for receiving at least one ball, wherein the ball backdrop corresponds to the ball-and-slot arrangement of the mechanical device.

With an acceleration of the shaft of the shaft assembly, the applied torque via the ball-and-slot arrangement causes a transmission to the inertial mass. If a high acceleration, which is caused by the shaft to be braked occurs, then a corresponding high torque is applied, which can not be transmitted via the clutch, because the flywheel is too sluggish.

It is considered to be particularly preferred if the two corresponding ball sliders are designed such that a rotation of the ball is ensured at a constant distance from the axis of rotation of the shaft of the mechanical device, wherein the depth of the ball sliders during the rolling of the ball symmetrically reduced in both directions, so that a simple release of the clutch can be realized.

Preferably, a spring assembly and to release the lock, an electromagnet are provided for inserting the lock, wherein the electromagnet and the mechanical device are mounted in a common housing, so that its longitudinal axis coincides with the axis of rotation of the shaft of the mechanical device. In this case, the armature of the electromagnet is preferably connected to the shaft by means of a bearing and can move in the axial direction together with the shaft. This happens when the clutch is released. The armature moves from the surrounding coil so much that the electromagnetic field is weakened, resulting in a collapse of the lock.

The shaft arrangement of the bidirectionally acting rotation lock or lock preferably has two serrations each with mutually opposite teeth, which can be brought into engagement with serrations of an inner and an outer toothed disc. These are rotatably and axially displaceably arranged in a housing so that the toothed disks successively engage with the teeth of the spur gear teeth when closing the lock. By this arrangement, on the one hand, a bidirectional rotation lock or lock can be provided, which has only a very low rotational play in the braked state and on the other hand rotational direction independent from the turn out can be inserted.

Particularly advantageous is considered when the lock has springs which serve to engage the lock, while the electromagnet acts to release the lock against the spring force. In airplanes, a computer typically executes the operation such that upon an actuation request, the correctness of the request is first checked and, upon successful verification, the power supply to the solenoid, which triggers the corresponding lock, is switched.

As a result, the magnetic field in the electromagnet is built up or broken down. Then there is power available to switch the lock.

Furthermore, it may be preferable to provide a conventional monitor concept to assure incidence when the rotational acceleration for the response of the spin acceleration sensitive mechanism is too low.

According to a further preferred embodiment of the invention, in the open position of the barrier, the axial path, the inner Tooth disc covers to its full engagement with its opposite toothing, at least twice as large as the axial distance that the outer toothed disc requires until its complete engagement with its opposite teeth. This ensures that the serrations do not interfere with each other during the engagement process.

Advantageously, the teeth are designed as opposite sawtooth profile. By reducing the number of teeth, the maximum speed at which braking can be initiated can be increased. However, this reduces the maximum transmissible torque. Depending on requirements, an optimization can be made here.

A further advantageous embodiment of the invention is that the shaft assembly is rotatably mounted in the housing by means of rolling bearings.

The shaft assembly may advantageously consist of a shaft and a toothed sleeve, which are firmly connected to each other with a threaded ring and a spline.

The toothed disks provided in the housing can be arranged in a rotationally fixed and axially displaceable manner via pins distributed uniformly over the circumference.

The invention further relates to a brake system for a drive train of slats and landing flap drives or threaded spindle drives for operating trimmable horizontal stabilizers, each having a lock with the features described in more detail above.

Furthermore, the invention relates to a threaded spindle drive for the positioning of a trimmable horizontal stabilizer of an aircraft with at least one barrier, which has the aforementioned inventive features. Advantageously, the shaft arrangement corresponds to the running in the threaded spindle of the threaded spindle drive.

Further features, details and advantages of the invention will be explained in more detail with reference to an embodiment shown in the drawing. Show it:

1 FIG. 4: a section through an embodiment of a bidirectional barrier, FIG.

2 a perspective view of a portion of the lock according to 1 in an exploded view,

3 : another detail of the lock accordingly 1 but in assembled condition,

4 FIG. 2: a section through a barrier according to the invention according to a preferred embodiment, FIG.

4a : An enlarged sectional view in the area of a ball-and-slot arrangement along the line AA according to 4 .

5 a perspective view of a portion of the rotation lock according to the invention 4 ,

1 shows an example of an embodiment of a lock, in which the insertion of the lock by spring force and the release by means of an electromagnet 150 . 160 . 170 . 180 he follows. A shaft assembly to be braked 20 , which may be, for example, the tie rod of a threaded spindle drive for operating trimable horizontal stabilizers of an aircraft is by rolling bearings 24 rotatable in a fixed housing 100 stored and consists of a shaft 22 and a toothed socket 26 that with a screw ring 50 and a spline 60 are firmly connected.

The wave arrangement 20 has two serrations with opposite sawtooth profile, as in 2 is shown. Possible to realize the present invention according to 4 but also other tooth forms. These spur gears opposite an outer toothed disc 70 and an internal toothed disc 80 , both of which also have serrations, so that they with the serrations of the shaft assembly 20 can engage in, as also in the 2 is shown.

The toothed discs 70 and 80 are about pins 90 rotationally fixed, but axially displaceable with the fixed housing 100 connected. The outer toothed disc 70 is made of several springs 110 in the direction of the opposite toothing applied with force (see. 3 ), using the force of spring plates 120 is transmitted through holes in the inner toothed disc 80 are intended to pass through. Accordingly, the inner toothed disc 80 of several springs 130 in the direction of the opposite toothing applied with force, the force of spring plates 140 directly on the inner toothed disc 80 is transmitted.

In the open state, as in 1 is shown, are the toothed discs 70 and 80 not engaged with their opposing gears as they are retained by an electromagnet. Like in the 1 represented exists the electromagnet from a coil 150 (which can also be constructed of several individual coils), a pot body 160 , an anchor 170 and a reflux body 180 , The anchor 170 is due to the current flowing through the coil 150 except for a stop on the pot body 160 attracted and holds over an axial stop 190 (see. 1 ) the inner toothed disc 80 against its spring force in the open position, in turn, an open position of the outer toothed disc 70 via an axial stop 200 brought against their spring force.

In order to prevent that the spur gear interferes with each other during the engagement process, it is necessary that in the open position of the barrier, the axial distance, the inner toothed disc 80 until its complete engagement with its opposite toothing, at least twice as large as the axial distance that the outer toothed disc 70 needed until fully engaged with their opposing teeth.

Is the energization of the coil 150 interrupted and the wave 20 counteracted with torque (same direction in 3 ), so it can rotate until the inner spur gear engages and ends the rotation form-fitting. The external teeth do not hinder this rotation, because the saw teeth slide off each other due to their orientation. Is the above rotation of the shaft 30 terminated as a result of engagement of the inner star gearing, so also the outer spur gearing has reached a rotational position to each other, which causes these also engages each other as a result of their spring force. The wave arrangement 20 is thus blocked with low backlash in both directions of rotation.

Upon rotation of the shaft 20 The blocking in both directions of rotation also takes place in a clockwise direction, but the sequence of engagement of the inner and outer teeth is reversed.

A preferred application of the aforementioned barrier results in the realization of a threaded spindle drive for the positioning of a trimable tailplane, in which the tie rod is braked in the threaded spindle. In this application, the speed and torsional rigidity of the tie rod are very low.

4 shows a lock according to the invention according to a preferred embodiment. It has the shaft arrangement 20 , similar in the 2 and 3 shown, two spur gears with counter-sawtooth profile, which are adapted to the particular design of the shaft assembly according to the present invention.

When used in a Gewindespindelstellgerät for trimming of aircraft elevators, the shaft 22 the shaft arrangement 20 be connected to the threaded spindle in the form that the torque and the axial load can be transmitted. The housing 100 For this purpose, it can be connected to the aircraft structure in order to be able to introduce the axial load and the locking torque into the aircraft structure.

The lock according to the invention in this case has a mechanical device 220 . 240 . 250 on, like, the 4 is removable, with one end with the shaft assembly 20 is connected such that a rotational mold closure is feasible, and with the other end with an inertial mass, here a flywheel 230 , is coupled, so that when applying an increased torque, the clutch detachable and the mechanical device 220 . 240 . 250 in axial direction from the flywheel 230 removing direction moves when a high torque is applied.

This arrangement is capable of the shaft 22 to lock very fast at high spin. The high locking speed is achieved in that it is a purely mechanical Sperrablauf, without the involvement of electrical and / or magnetic processes.

The mechanical device 220 . 240 . 250 has a wave 220 and an associated ball-and-slide arrangement 240 . 250 on, which is like in 5 shown at the end of the shaft 220 which is the flywheel 230 is adjacent. The mechanical device is as out 4 visible in the housing 100 the lock mounted so that the axis of rotation 220 ' the wave 220 coincides with the longitudinal axis of the barrier.

The wave 22 is via a clutch wheel 210 and the wave 220 with the flywheel 230 connected. The coupling wheel 210 has an internal and external spline, thus provides a rotational form fit between shaft 22 and wave 220 and allows axial movement of the shaft 220 and the application of a force by means of spring 260 which, as in 4 shown in a cone-shaped recess 28 the wave 22 is appropriate.

The wave 220 is over the ball backdrop arrangement 240 . 250 with the flywheel 230 connected. The ball backdrop arrangement 240 . 250 may consist of at least one ball, in this embodiment, three balls 240 and three ball scenes each 250 (see. 5 ), which in the wave 220 are incorporated, are provided. The flywheel 230 also has corresponding ball backdrops 250 ' on, as the enlarged representation in 4a is removable. Thus, both serve ball scenes 250 . 250 ' for receiving the respective ball 230 ,

The shape of the ball backdrop 250 is in 5 and on average AA the 4 shown. It ensures a rolling of the ball at a constant distance from the axis of rotation of the shaft 220 , wherein the depth of the backdrop and thus the "immersion depth" of the ball is reduced during the rolling. Starting from the lowest point of the ball, the reduction of the slide depth is identical for both roll directions. The ball backdrops in the wave 220 and the flywheel 230 stand opposite each other and take the balls 240 on. The wave 220 and the flywheel 230 be by the spring 260 and by the electromagnetic force acting on the excited coil 150 on the anchor 170 is exercised, axially over balls 240 kept in contact. The held together by spring and magnetic force ball guide arrangement ensures on the one hand a torque input from the shaft 220 in the flywheel 230 and on the other hand one from the flywheel 230 removing, axial movement of the shaft 220 depending on the amount of torque, but regardless of the direction.

Will the wave 20 accelerates, then requires the flywheel 230 an acceleration moment corresponding to its inertia. This is initiated by the ball track arrangement, which in turn requires axial force. If the axial force is too low, then an axial movement of the shaft takes place 220 and caused a collapse of the lock. The axial movement of the shaft also has the consequence that the anchor 170 the electromagnet moves so much that it is moved out of the coil that it can no longer hold the anchor, so that the lock is incident. The movement of the armature leads to a change in the current (when supplying the electromagnet with constant voltage) or to a change in the PWM ratio (PWM = pulse width modulation when supplying the electromagnet with constant current by means of PWM current control). This change is detected and leads to the switching off of the electromagnet to ensure a permanent lock.

The arrangement also has a conventional monitoring to detect a malfunction in the way that by means of continuous comparison of the commanded rotational position of the shaft 22 that of a rotation angle sensor 270 measured actual rotational position detected a discrepancy, turned off in consequence of the solenoid and thus the lock is brought about. Is the acceleration of the wave 10 For a responsive spin-sensitive mechanism too low, then the shutdown is performed by this monitoring function.

By reducing the magnitude of the current through the solenoid, the magnetic force, and thus the spin acceleration required to engage the barrier, can be reduced. This situation can be used to advantage for checking the arrangement, such that the current intensity is reduced to such an extent that the maximum spin, which can be generated regularly by the drive of the spindle, is sufficient to cause the barrier to engage. There is thus no access to the threaded spindle actuator required and the test can be carried out automatically. Advantageously, this functional test is carried out immediately after the landing of the aircraft, for example during taxiing of the aircraft to its stand, since at this time the probability is high that an optionally existing, dysfunctional icing is still present within the actuator.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 69826565 T2 [0006]
• AT 409533 B [0007]
• US 6109415 A [0010]

Claims (18)

Bidirectional rotation lock or lock for a shaft arrangement ( 20 ) with at least one wave ( 22 ), characterized in that a mechanical device ( 220 . 240 . 250 ) provided with one end with the shaft arrangement ( 20 ) is connected such that a rotational mold closure is feasible, and with the other end with an inertial mass ( 230 ) is coupled, so that when applying an increased torque, the clutch detachable and the mechanical device ( 220 . 240 . 250 ) Is movable in the axial direction, so that a collapse of the lock can be realized. Lock according to claim 1, characterized in that the mechanical device ( 220 . 240 . 250 ) along the longitudinal axis ( 220 ' ) of the lock extends and a shaft ( 220 ) and a ball-and-gate arrangement ( 240 . 250 ) with at least one ball ( 240 ), in a setting ( 250 ) is rotatably mounted, has. Lock according to one of claims 1 or 2, characterized in that an acceleration of the shaft ( 22 ) of the shaft arrangement ( 20 ) a transmission of torque via the ball-and-slot arrangement ( 240 . 250 ) on the inert mass ( 230 ) brought about. Lock according to one of the preceding claims, characterized in that the inert mass is preferably a flywheel ( 230 ), which is at least one of the ball backdrop ( 250 ) of the ball-and-gate arrangement ( 240 . 250 ) corresponding ball backdrop ( 250 ' ) for receiving the ball ( 240 ) having. Lock according to one of the preceding claims, characterized in that the two corresponding ball scenes ( 250 . 250 ' ) are formed such that a rotation of the ball ( 240 ) at a constant distance from the axis of rotation of the shaft ( 220 ), whereby the depth of the ball scenes ( 250 . 250 ' ) while rolling the ball ( 240 ) is symmetrically reduced in both directions, so that a release of the clutch can be realized. Lock according to one of the preceding claims, characterized in that for inserting the lock a spring arrangement ( 110 . 130 ) and to release the lock an electromagnet ( 150 . 160 . 170 . 180 ) are provided, wherein the electromagnet in such a common housing ( 100 ) with the mechanical device ( 220 . 240 . 250 ) is arranged, that its longitudinal axis with the axis of rotation of the shaft ( 220 ) and where the anchor ( 170 ) of the electromagnet with the shaft ( 220 ) is preferably connected by means of a storage. Lock according to claim 6, characterized in that the axial part of the flywheel ( 230 ) removing movement of the mechanical device ( 220 . 240 . 250 ) an axial movement of the associated armature ( 170 ) of the electromagnet ( 150 . 160 . 170 . 180 ), so that it leaves the surrounding coil ( 150 ) moved so much that the electromagnetic field is weakened, so that the lock is incident. Lock according to claim 6 or 7, characterized in that by reducing the strength of the current through the electromagnet, the magnetic force and thus the spin acceleration required for the collapse of the lock can be reduced. Lock according to one of the preceding claims, characterized in that the flywheel ( 230 ) in the housing ( 100 ), or in a housing ( 100 ' ) connected to the housing ( 100 ) is firmly connected. Lock according to one of the preceding claims, characterized in that the shaft arrangement ( 20 ) has two serrations each with mutually opposite teeth, which with spur gear teeth of an inner and an outer toothed disc ( 80 . 70 ) are engageable in the housing ( 100 ) are arranged such rotationally fixed and axially displaceable that the toothed discs ( 80 . 70 ) successively engage with the teeth of the spur gear teeth when closing the lock. Lock according to one of the preceding claims, characterized in that in the open position of the barrier, the axial distance, the inner toothed disc ( 80 ) to its full engagement with its opposite toothing, at least twice as large as the axial distance that the outer toothed disc ( 70 ) is required until its complete engagement with its opposite toothing. Lock according to one of the preceding claims, characterized in that the teeth have a tooth profile, for. B. a sawtooth profile, which ensures that upon application of a torque, the tooth-supporting body in a rotational direction mutually learn form-fitting and allow each other in the opposite direction of rotation. Lock according to one of the preceding claims, characterized in that the shaft arrangement ( 20 ) by means of rolling bearings ( 24 ) rotatable in the housing ( 100 ) is stored. Lock according to claim 13, characterized in that the shaft arrangement ( 20 ) from the to braking shaft ( 22 ) and a toothed bushing ( 26 ), which with a screw ring and a spline ( 28 ) are firmly connected. Lock according to one of the preceding claims, characterized in that the toothed discs ( 70 . 80 ) via equally distributed pins ( 90 ) are arranged rotationally fixed and axially displaceable. Brake system for a drive train of slat and flapper drives or threaded spindle drives for actuating trimmable horizontal stabilizers with a lock according to one of claims 1 to 15. Threaded spindle drive for the positioning of a trimmable tailplane with at least one lock according to one of claims 1 to 15. Screw spindle drive according to claim 17, characterized in that the shaft ( 22 ) which is in the threaded spindle extending tie rod of the threaded spindle drive.

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