DE202017107344U1 - Clamping device for a passive safety brake and safety brake with it - Google Patents

Abstract

Clamping device for a passive safety brake (1), in particular passive safety brake (1) of a crane or a wind turbine, wherein the safety brake (1) in case of release by means of stored tension energy is incident, with a spring accumulator, the at least one tensionable spring (5) for storing having the clamping energy, with a translationally movable and with the spring (5) coupled to the piston (3), by means of which the spring (5) can be tensioned and by means of which the safety brake (1) can occur with a on the piston (3) attacking Drive train (7) for tensioning the spring (5) and with a rotary drive (8), in particular motor, which has a motor shaft (9) and the drive train (7) by means of the motor shaft (9) for tensioning the spring (5) can drive , wherein the drive train (7) has an eccentric arrangement (14) with a rotatably movable eccentric shaft (15) and a connecting rod (26), which the eccentric shaft (15) with the piston n (3) connects, characterized in that the drive train (7) has a coupling (17) for a switchable load separation of the eccentric shaft (15) from the rotary drive (8).

Description

The invention relates to a brake application device for a passive safety brake according to the preamble of claim 1. Furthermore, the invention relates to a safety brake with the application device. The safety brake is in particular a passive safety brake of a crane or a wind energy plant. The safety brake is designed such that it occurs in the event of its release by means of stored tension energy. For this purpose, the application device on a spring accumulator, which has at least one tensionable spring for storing the clamping energy.

In a crane, the safety brake is used to brak a rope on which a load is lowered in a short time. In a wind turbine, for example, it is important for maintenance work to reliably brake the rotor hub.

Safety brakes are also known in the form of brake devices for vehicles. DE 27 10 585 C2 shows such a braking device for vehicles, which is particularly intended for rail vehicles. In this case, a translationally movable and coupled to the spring piston is provided, by means of which the spring can be tensioned and by means of which the safety brake can occur. For tensioning the spring there is a drive train acting on the piston. The drive train has a rotary drive, in particular a motor. The rotary drive has a motor shaft and can drive the drive train by means of the motor shaft for tensioning the spring. Next, the drive train on an eccentric arrangement. The eccentric arrangement has a rotatably movable eccentric shaft and a connecting rod which connects the eccentric shaft with the piston.

Based on the known prior art, the present invention seeks to improve a passive safety brake to the effect that they not only always invariably incident but also triggers particularly quickly.

The invention solves this problem with a brake application device according to claim 1 and with a safety brake according to claim 12.

In a Zuspannvorrichtung for a passive safety brake, in particular passive safety brake of a crane or a wind turbine, the safety brake in the case of their triggering by means of stored energy span, with a spring accumulator, which has at least one tensionable spring for storing the clamping energy, with a translationally movable and with the spring-coupled piston, by means of which the spring can be tensioned and by means of which the safety brake can occur, with a piston engaging the drive train for tensioning the spring and with a rotary drive, in particular motor, which has a motor shaft and the drive train by means of the motor shaft for clamping can drive the spring, wherein the drive train comprises an eccentric having a rotatably movable eccentric shaft and a connecting rod, which connects the eccentric shaft by means of pistons, the invention provides that the drive train is a Kup Plung for a switchable load separation of the eccentric shaft of the rotary drive has.

The coupling has an electrical power supply. So it is an electrical voltage needed to close the clutch and keep it closed. For this purpose, in particular an armature disk of the clutch is tightened in the direction of a rotor of the clutch. If the safety brake is to be activated, the clutch, which has been opened after interruption of the power supply, ensures that the eccentric shaft can rotate freely relative to the rotary drive. The spring can therefore relax while applying a brake pad against a brake disc by means of the piston. Thanks to the load separation from the rotary drive, this is particularly fast. Even with an unwanted power failure, the safety brake is automatically applied. The safety brake can always be used safely even if the drive fails. The drive is not needed to collapse the safety brake. Even if the clutch fails, the safety brake may not be able to ventilate, but it is safe to fall in at any time.

The drive train preferably has a transmission interposed between the motor shaft on the one hand and the eccentric shaft on the other hand. In this case, the transmission has a transmission drive shaft drivable by the rotary drive and a transmission output shaft. The transmission is in particular a reduction gear. Thanks to the gearbox, the spring can be tensioned with comparatively low torque of the rotary drive.

The clutch is preferably the transmission output shaft on the one hand and the eccentric shaft interposed on the other hand. As a result, not only a load separation from the rotary drive, but also a load separation from the transmission is achieved by means of the coupling. If the safety brake comes in, the gearbox does not need to be moved for this purpose. If the transmission fails, the safety brake automatically engages.

The transmission is preferably not self-locking, but alternatively self-locking educated. According to a preferred embodiment of the invention, the transmission is a worm gear, in particular a worm gear without secure self-locking. Alternatively, the transmission is, for example, a planetary gear or another gear known to the expert.

The eccentric shaft has in particular an eccentric on which the connecting rod is articulated. According to an advantageous embodiment of the eccentric shaft is associated with a position switch for determining a defined end position of the eccentric. More preferably, the application device is adapted to switch from clamping to holding the spring, when the defined end position of the eccentric is determined. The defined end position is preferably close to the top dead center of the eccentric. In particular, the defined end position is located in a rotational angle of the eccentric shaft from the top dead center of the eccentric, which is between 1 ° and 60 °. More preferably, this angle of rotation between 1 ° and 30 ° and even more preferably between 1 ° and 20 °. The top dead center of the eccentric is the point at which the spring would be maximally stretched, after which, therefore, the direction of movement of the piston would turn around.

The clutch has, in particular, two friction surfaces, a clutch spring which repels the friction surfaces, and a magnetic coil, which in the case of its power supply frictionally connects the friction surfaces with one another. This is done in particular by the fact that the solenoid coil attracts an armature slide of the clutch against the force of the clutch spring in the direction of a rotor of the clutch. The armature disk and the clutch are each assigned one of the friction surfaces. When the power supply drops, the clutch spring retracts the armature disk from the rotor and thus ensures the load separation of the eccentric shaft from the rotary drive. The clutch is therefore preferably an electromagnetic friction clutch. Alternatively, the clutch is a toothed clutch or other coupling known to those skilled in the art. The clutch spring, that is the spring of the clutch, is preferably a return spring, which attracts the armature disk. The clutch spring is in this case a tensioned with train spring. In an alternative embodiment of the invention, the clutch spring is a compressible spring with pressure.

The invention has recognized that thanks to the eccentric arrangement in the vicinity of the top dead center of the eccentric, so when holding the spring of the spring accumulator, only comparatively small forces are necessary and therefore only relatively small forces are necessary to keep the clutch closed, ie to prevent the load separation by means of the clutch spring. According to a particularly advantageous embodiment of the invention it is therefore provided that the application device has a control which operates the clutch for tensioning the spring with a first power stage and the clutch for holding the spring, in particular by lowering a supply voltage of the clutch, with respect to the first power level reduced second power level operates. The application device according to the invention therefore requires only comparatively little energy for holding the spring in place and is therefore particularly energy-saving. The supply voltage of the coupling is in particular the supply voltage for operation of the magnetic coil. The lowering of the supply voltage is preferably carried out by means of pulse width modulation.

In a preferred embodiment of the invention it is provided that the drive train has a freewheel in the form of an overrunning clutch between the eccentric shaft and the coupling. The clutch has an armature disc which is rotatably connected to the freewheel. The freewheel permits free rotation of the armature disk relative to the eccentric shaft only in one direction of incidence rotation. This incident direction of rotation is defined by the direction of rotation of the armature disk and the eccentric shaft relative to a bearing of the eccentric shaft upon collapse of the safety brake. Thus, when the safety brake is applied, the eccentric shaft and the clutch rotate together in the direction of incidence rotation. The rotation of the eccentric shaft is then abruptly stopped when the brake pad is pressed by means of the piston to the brake disc. Thanks to the freewheel, the armature disc can rotate freely, so that the drive train is relieved. Alternatively or in addition to the freewheel in the drive train, an eddy current brake is provided, by means of which the armature disk is braked.

Between the rotary drive and the clutch, in particular on the gear drive shaft or on the motor shaft, a motor freewheel in the form of a backstop is preferably arranged, which allows rotation of the motor shaft only in a drive direction of rotation of the rotary drive. The drive direction of rotation of the rotary drive is the direction of rotation, which occupies the rotary drive for tensioning the spring. Due to the backstop, the drive can not assume any other direction of rotation. The engine freewheel in the form of the backstop keeps the spring of the spring loaded, without having to burden the engine. This is particularly advantageous if no self-locking gear is used.

In particular, when the engine freewheel is omitted, it is provided according to a development of the invention that the rotary drive a dynamic is controllable engine and that the application device has a control which is designed to control the engine in response to a desired braking value and a determined actual braking value such that the target braking value approaches the actual braking value. Thus, the passive safety brake is also used as an active service brake, the necessary brake pressure is adjusted and readjusted by means of the engine. The brake is designed such that the operating mode can be selected, wherein the brake is operated in a first mode as the passive safety brake according to the invention and in a second mode as an active service brake. This may be useful, for example, in wind turbines, if an active service brake function is required for maintenance.

Further embodiments will become apparent from the claims, from the drawing and from the following description of an embodiment of the invention shown in the drawings. In the drawings show:

1 a passive safety brake with application device according to an embodiment of the invention in a side sectional view; and

2 the passive safety brake of the embodiment of 1 in a simplified schematic representation.

In 1 is the passive safety brake with the reference numeral 1 designated. The safety brake 1 has a brake pad 2 , a piston 3 , a caliper 4 and a spring 5 on. By means of the preloaded spring 5 can the piston 3 the brake pad 2 Press against a brake disc and thus brake the brake disc.

To tension the spring, the safety brake 1 a clamping device 6 with a drive train 7 and a rotary drive 8th in the form of an electric motor. By means of the rotary drive 8th can the spring 5 over the powertrain 7 be tense. The rotary drive 8th has a motor shaft 9 and a motor freewheel 10 in the form of a backstop. About the motor shaft 9 is the rotary drive 8th with the drive train 7 coupled. The engine freewheel ensures this 10 for that the motor shaft 9 can rotate in one drive direction, but is locked in the opposite direction. This allows the spring 5 by means of the rotary drive 8th be stretched and also after switching off the rotary actuator 8th stay curious.

The drive train 7 has a gearbox 11 in the form of a worm gear. The gear 11 is via a transmission input shaft 12 with the motor shaft 9 coupled and sets a rotation of the transmission input shaft 12 by means of a reduction gear in a rotational movement of a transmission output shaft 13 around.

The drive train 7 also has an eccentric arrangement 14 with an eccentric shaft 15 and a freewheel 16 in the form of an overrunning clutch and a coupling designed as a friction clutch 17 on. About the clutch 17 and the freewheel 16 is the transmission output shaft 13 with the eccentric shaft 15 coupled such that during operation of the rotary drive 8th and closed clutch 17 a torque from the transmission output shaft 13 on the eccentric shaft 15 is transmitted. An anchor disk 18 the clutch 17 this is due to a rotor 19 the clutch 17 on, with the rotor 19 on a coil side of the coupling 17 is arranged. For this purpose, the anchor plate 18 a first friction surface 20 up and assigns the rotor 19 a second friction surface 21 on. The friction surface 20 is against the force of a clutch spring 22 by means of an energized magnetic coil 23 against the friction surface 21 drawn. Once the solenoid 23 is de-energized, there is a load separation of the eccentric shaft from the rotary drive by means of the clutch spring 22 , The load separation is thus by interrupting the power supply for the solenoid coil 23 switchable.

The freewheel 16 is only active when the anchor plate 18 contrary to the direction of rotation to tension the spring 5 would like to turn faster than the eccentric shaft 15 , Therefore, the cocked spring remains 5 over the eccentric shaft 15 , the freewheel 16 , the closed clutch 17 and the gearbox 11 by means of the motor freewheel blocking in the return direction 10 held. If, however, after opening the clutch 17 the feather 5 for inserting the safety brake 1 relaxed and thereby the eccentric shaft 15 together with the anchor disc 18 set in rotation, the anchor plate can 18 thanks to the freewheel 16 continue to turn when the rotation of the eccentric shaft 15 with completely inserted safety brake 1 is stopped abruptly. As a result, the eccentric arrangement 14 relieved overall.

The eccentric shaft 15 is by means of a storage 24 rotatably mounted. About one on the eccentric shaft 15 arranged eccentric 25 is a connecting rod 26 at the eccentric shaft 15 hinged. The connecting rod 26 is by means of a bolt 27 with the piston 3 connected. This will cause a rotational movement of the eccentric shaft 15 in a translatory movement of the piston 3 implemented.

The powertrain 7 is in a housing 28 installed and stored. The housing 28 is on the caliper 4 screwed. Inside the case 28 is also at least one position switch 29 arranged the position of the eccentric 25 senses and by means of which a not shown control unit of the application device 6 recognizes when the eccentric 25 while tensioning the spring 5 reaches a defined end position. This defined end position is achieved before the eccentric 25 could reach its top dead center.

In the defined end position of the eccentric 25 the force of the spring acts 5 largely perpendicular to the possible direction of movement of the eccentric 25 at the eccentric shaft 15 , For holding the spring 5 are therefore lower forces and consequently lower holding forces between the friction surfaces 20 and 21 necessary, as for tensioning the spring 5 needed. A control unit of the application device 6 Hold the spring 5 therefore stretched by means of a savings circuit. The economy circuit energizes the solenoid 23 by means of a pulse width modulation or otherwise with lowered supply voltage and thus with reduced power and can thereby also the required torque or holding torque for holding the spring 5 muster.

The safety brake according to the invention 1 thanks to the load separation due to the switchable coupling 17 close very quickly. The rotary drive 8th as well as the transmission 11 must not be moved during braking, which leads to a significant reduction in inertia. Thanks to the invention, a closing time of about 100 milliseconds including the reaction time and the switching time of all electrical components can thus be achieved.

For fast collapse of the safety brake 1 also carries the when holding the feather 5 solenoid operated with reduced power 23 the clutch 17 at. That compared to the magnetic field, which is used to tension the spring 5 is built, relatively lower magnetic field of the clutch 17 can namely be reduced in a relatively shorter time and thus for a faster decoupling of the armature disk 18 from the rotor 19 to care.

The short reaction times of the safety brake according to the invention 1 make it possible, for example, to decelerate and catch a falling load much faster, before it develops a high translational energy due to the mass acceleration, which could then be reduced only in a much longer time or with a much greater brake pressure. As a result, for example, the safety brake 1 overall smaller and thus cost-effective dimensions. Also when using the safety brake 1 In wind turbines, a lower energy to be braked leads to less wear of the brake pad 2 and thus overall to a longer service life of brake pads. Thanks to the invention, increased safety in safety brakes 1 or cost savings can be achieved with at least the same level of security.

2 schematically shows the safety brake 1 of the embodiment of 1 , Shown are only some essential to the invention components of the safety brake 1 , Like reference numerals in the figures indicate like parts. Across from 1 additionally shown and with the reference numeral 30 is designated in the description too 1 already mentioned brake disc.

All the features mentioned in the preceding description and in the claims can be combined in any selection with the features of the independent claims. The disclosure of the invention is therefore not limited to the described and / or claimed combinations of features, but all meaningful in the context of the invention feature combinations are to be regarded as disclosed.

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 2710585 C2 [0003]

Claims (12)

Clamping device for a passive safety brake ( 1 ), in particular passive safety brake ( 1 ) of a crane or a wind turbine, the safety brake ( 1 ) in the case of its release by means of stored tension energy, with a spring accumulator, the at least one tensionable spring ( 5 ) for storing the clamping energy, with a translationally movable and with the spring ( 5 ) coupled pistons ( 3 ), by means of which the spring ( 5 ) and by means of which the safety brake ( 1 ), with one on the piston ( 3 ) engaging powertrain ( 7 ) for tensioning the spring ( 5 ) and with a rotary drive ( 8th ), in particular motor, which has a motor shaft ( 9 ) and the drive train ( 7 ) by means of the motor shaft ( 9 ) for tensioning the spring ( 5 ), wherein the drive train ( 7 ) an eccentric arrangement ( 14 ) with a rotatably movable eccentric shaft ( 15 ) and a connecting rod ( 26 ), which the eccentric shaft ( 15 ) with the piston ( 3 ), characterized in that the drive train ( 7 ) a coupling ( 17 ) for a switchable load separation of the eccentric shaft ( 15 ) from the rotary drive ( 8th ) having. Clamping device according to claim 1, characterized in that the drive train ( 7 ) one of the motor shaft ( 9 ) on the one hand and the eccentric shaft ( 15 ) On the other hand, intermediate transmission ( 11 ) with one of the rotary drive ( 8th ) drivable transmission input shaft ( 12 ) and a transmission output shaft ( 13 ) having. Clamping device according to claim 2, characterized in that the coupling ( 17 ) of the transmission output shaft ( 13 ) on the one hand and the eccentric shaft ( 15 ) is interposed on the other hand. Clamping device according to one of claims 2 and 3, characterized in that the transmission ( 11 ) is a worm gear, in particular without secure self-locking, is. Clamping device according to one of the preceding claims, characterized in that the eccentric shaft ( 15 ) an eccentric ( 25 ), on which the connecting rod ( 26 ) is hinged that the eccentric shaft ( 15 ) a position switch ( 29 ) for determining a defined end position of the eccentric ( 25 ) and that the application device ( 6 ) is adapted, from the clamping to holding the spring ( 5 ), when the defined end position of the eccentric ( 25 ) is determined. Clamping device according to one of the preceding claims, characterized in that the coupling ( 17 ) two friction surfaces ( 20 . 21 ), one the friction surfaces ( 20 . 21 ) repulsive clutch spring ( 22 ) and a magnetic coil ( 23 ), which in the case of their power supply, the friction surfaces ( 20 . 21 ) connects non-positively with each other. Clamping device according to one of the preceding claims, characterized in that the coupling ( 17 ) is an electromagnetic friction clutch. Clamping device according to one of the preceding claims, characterized in that the application device ( 6 ) has a control which the coupling ( 17 ) for tensioning the spring ( 5 ) operates at a first power level and the clutch ( 17 ) for holding the spring ( 5 ), in particular by lowering a supply voltage of the clutch ( 17 ) operates with a reduced compared to the first power level second power level. Clamping device according to one of the preceding claims, characterized in that the drive train ( 7 ) a freewheel ( 16 ) in the form of an overrunning clutch between the eccentric shaft ( 15 ) and the clutch ( 17 ), that the coupling ( 17 ) one with the freewheel ( 16 ) non-rotatably connected armature disc ( 18 ) and that the freewheel ( 16 ) a free rotation of the armature disc ( 18 ) relative to the eccentric shaft ( 15 ) is permitted only in a direction of incidence, which is determined by the direction of rotation of the anchor plate ( 18 ) and eccentric shaft ( 15 ) relative to a storage ( 24 ) of the eccentric shaft ( 15 ) when the safety brake ( 1 ) is defined. Clamping device according to one of the preceding claims, characterized in that between the rotary drive ( 8th ) and the clutch ( 17 ), in particular on the transmission input shaft ( 12 ) according to claim 2 or on the motor shaft ( 9 ), a motor freewheel ( 10 ) is arranged in the form of a backstop, the rotation of the motor shaft ( 9 ) only in one drive direction of rotation of the rotary drive ( 8th ) allows. Clamping device according to one of claims 1 to 9, characterized in that the rotary drive ( 8th ) is a dynamically controllable engine and that the application device ( 6 ) has a controller which is designed to control the motor in response to a desired braking value and a determined actual braking value such that the desired braking value approaches the actual braking value. Safety brake, in particular for a crane or for a wind turbine, wherein the Safety brake ( 1 ) is designed to fall in the case of its release by means of stored tension energy and for this purpose a Zuspannvorrichtung ( 6 ) according to one of the preceding claims.

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