EP3624110A1 - Drive for a bell and method for ringing a bell - Google Patents

Abstract

An arrangement equipped with a counter-pendulum device for ringing a bell (1) suspended in a bell axis (5) is characterized in that the counter-pendulum device comprises at least one counter-pendulum (16, 17) which is freely swinging relative to the bell axis (5), and that the at least one counter pendulum (16, 17) is driven by at least one linear motor (12, 13).

Description

The invention relates to an arrangement for ringing a bell mounted in a carrying device according to the preamble of patent claim 1.

For ringing, bells are made to oscillate. In the steady state, a clapper, which is suspended in the middle of the bell, strikes the brass knuckle of the bell rib. The bells are usually hung in towers, especially in church towers, so that they can be heard as far as possible.

The pendulum movement creates horizontal and vertical bearing forces that are transferred to the bell tower via the bell bearing. These bearing forces accordingly act periodically on the tower at the pendulum frequency of the bell. This leads to a critical state if the bell tower's natural bending frequency matches the bell's pendulum frequency or a multiple thereof. Cases in which the bending natural frequency of the bell tower coincides with the fundamental frequency of the pendulum movement of the bell or a multiple occur repeatedly.

However, bells are generally ringed with a relatively large ringing angle, which is usually between 50 ° and 80 °, in some cases even higher. Due to the geometric non-linearity, the bearing forces also contain components with multiples of the pendulum frequency, i. h, higher harmonics. The horizontal bearing forces contain odd-numbered multiples of the pendulum frequency, while the vertical bearing forces only contain even-numbered multiples of the pendulum frequency. In addition to the horizontal bearing forces, the eccentric bell bearing also causes the vertical bearing forces to shift horizontally on the tower. If a harmonic of the bearing force resonates with the first natural bending frequency of the tower, strong vibrations can occur. These vibrations can lead to cracking or even destruction of the tower.

This phenomenon in itself is known. A number of solutions have been proposed to solve this problem.

Out DE 238 392 C. and DE 249 776 C. Arrangements for lifting the lateral forces of vibrating bells by means of counter pendulums have already become known. While according DE 238 292 C. it is provided that the same static moment of the counter pendulum vibrating synchronously and in the opposite phase is achieved with the smallest mass of the counter pendulum, by DE 249 776 C. discloses a counter pendulum vibrating against the bell, the mass of which should be compressed around the center of the vibration in such a way that the counter pendulum can be accommodated in the spaces between the bell and the bell chair frame.

Also AT 3465 U1 discloses a ringing device with a counter pendulum which, seen in the direction of the plane of vibration of the bell, has pendulum elements arranged to the left and right of the bell. If the vibration axes of the bell and the counter pendulum coincide, the forces of the bell and the counter pendulum do not compensate in the bell chair, but directly in the same axis, supporting counter-forces of the motor or reversing gear are introduced into the structure

On the other hand, are out DE 44 36 905 A1 a method and a device for controlling a vibrating load driven by a linear motor, for example a bell, with a linear motor, which functions without a force transmission via cables to the bell, in that a linear motor transmits its drive torque via a fixed connection to the bell yoke Reaction rail transfers to the bell. The supporting moment is introduced into the structure.

With the known procedures, the technical problems of ringing bells could only be solved in an imperfect manner. When bells ring, side shear forces are generated which are transferred from the bell chair to the masonry of the tower.

An ideal acoustic ringing, as desired by the bell experts in Central Europe, although the ringing habits are different, results when the bell is fully operational and hung below its axis pivot. Deducting the mass of the steel or wood axis results in a mass distribution of approx. 90% to 10% for the steel or wood axis for the bell. With the optimal design of the weight ratios of the coupled pendulum (bell / clapper), this suspension results in a clapper stop (in the millisecond range), which ideally leads to a sound-like excitement of the bell when the bell rises freely and vibrates at full ringing height. Regularly changing angular velocities result in a regularly changing Doppler effect.

The disadvantages of this suspension are considerable side shear forces on bell towers and structural parts such as bell chairs, screw connections, etc., which generally lead to considerable construction costs in order to counteract the feared cracking and gradual destruction of the building structure. When vibrational resonance occurs, the side thrust forces become so strong that they can even cause a tower to collapse.

Building dynamics, structural engineers and DIN 4178 therefore require that only a little sideshift is permitted and that the vibration frequencies of a plurality of bells have a sufficient frequency spacing. As a rule, counterweights are attached above the bell; in addition, the bells are often mounted in a cranked axis, i.e. the center of gravity of the bell is shifted towards the pivot point. Both lead to considerable acoustic disadvantages, in particular the Doppler effect and even to a failure of the bell and clapper system.

The known two drive variants, namely an electric motor, which can also be a linear motor, or a rope wheel, introduce a moment into the structure. As a result, especially during continuous ringing, but also during the ringing, lateral shear forces arise, which cause the structure to move, as well as non-ideal bobbin stops, a delayed swinging back of the structure or structure, which in turn leads to reinforced or delayed bell stops. These non-ideal stops lead to premature wear or destruction of the bells. Due to the high side drawers, an elastic-damping attachment is not possible. As a result, structure-borne noise can be transmitted.

Based on this knowledge of the problems, the acoustic demands of the bell experts and the technical demands of the structural engineers when building bell ringing systems are therefore not compatible.

In exceptional cases, counter-pendulum systems are installed for lifting the side-thrust problem, in which a counter-oscillating pendulum cancels the side-thrust forces, as in the one mentioned above AT 3465 U1 is described. Although these counter-pendulum systems largely eliminate the side thrust problem, they also have several disadvantages; in addition to the bell drive, they take up more space and require complex manufacture and reconstruction of the supporting structure. Supportive forces continue to be introduced into the tower structures in these constructions.

The necessary use of gear or cable gear wheels creates additional problems: imprecisely set counter pendulums create imprecisely defined bobbin stops. Due to the gear or rope play, the clapper is opposed to a changing flywheel mass when it hits the free-swinging bell at the upper turning point. This is the ideal weight balance of the clapper to the bell weight, such as in Conference report on the 2nd bell symposium ECC-ProBell from March 21 - 22, 2018, published by Andreas Rupp, Michael Plitzner, Göttingen, 2018.1. Edition , is not possible.

The side thrust of the bells, as well as unclean bobbin stops, require a rigid attachment of the bearings. In connection with additional mechanical noises, however, this leads to strong structure-borne noise transmission into the masonry of the tower and into the nave. The additional mechanical components lead to a greater feed-in of energy in order to keep the more inert and heavier ringing system at the set ringing angle. As a result, the supporting moments of the drive machines and gearboxes described at the beginning also increase.

It is the object of the invention to provide a bell ringing drive which solves this problem.

According to the invention, this object is achieved, as stated in claim 1.

Advantageous developments of the invention result from the subclaims and the description, in particular in connection with the drawings.

According to the invention, the at least one counter pendulum carries the stator or rotor of the linear motor, the bell with its axis carries the associated rotor or stator.

Preferably, the stator or rotor of the linear motor is mounted on the at least one counter pendulum, and the rotor or stator of the linear motor is mounted on a bracket that can be pivoted together with the bell and is rigidly connected to the bell axis in the vicinity of the counter pendulum. The combination of the counter pendulum with the drive, the counter pendulum comprising part of the drive, enables a very compact design compared to the prior art, in the form of a direct drive without a reduction gear

An arrangement according to the invention with a bell does not affect other bells, so that no undefined bobbin stops such as z. B. bumps arise. The stability of the tower in which the bell is suspended is increased by the additional weight generated by the counter pendulum. Even a tower foundation that has been rolled out or destabilized by the undesirable vibrations of bells that have been transferred to the tower is stabilized again by the additional weight. By using the invention, simpler structures of the tower and / or the bell chair are possible.

In order to keep the bending, twisting or vertical torsion of the axis carrying the bell within narrow limits, according to a further advantageous embodiment of the invention, a counter pendulum is arranged on either side of the bell, at least one of which carries a stand or a rotor of a linear motor . The aim is to keep the distance between the bell and the counter pendulums as small as possible in order to limit the bending of the axis to the smallest possible space.

In order to compensate for any existing differences in the bearing friction, the two counter pendulums are connected to one another via a bracket. Alternatively, linear motors can be provided as drives on both sides of the bell or on the connecting bracket, which are completely synchronized with one another, even if there is no bracket. However, this assumes that the bearing friction is identical on both sides. According to the invention, only one linear motor arranged in the area of the bracket is provided in one embodiment; this creates a particularly compact embodiment of the invention.

The at least one counter pendulum is preferably designed as a physical pendulum, the mass distribution of which corresponds to the mass distribution of the bell. This means that the counter pendulum has the same mass distribution as the bell in relation to its longitudinal axis. In order to obtain a counter-pendulum that is as compact as possible, it is preferably also made of bronze, lead or of cheaper, but less dense steel, for example stainless steel.

In order to be able to achieve an exact adaptation to the mass distribution of the bell and to enable fine adjustment even in the installed state, it is provided in a further advantageous embodiment of the invention that the at least one counter pendulum is attached in a height-adjustable manner with respect to the axis.

At least one of the counter pendulums preferably has at least one receiving device for receiving an additional weight.

In addition, it can advantageously be provided that the at least one linear motor is connected to an angle sensor which determines the angular position of the bell and that the linear motor can be driven by a control device as a function of the angular position of the bell. This makes it easy to determine which energy supply is required to reach a steady state after the ringing process or at which bell swing an optimal sound result is achieved.

The invention relates to a method for ringing a bell using an arrangement as described above.

The invention thus creates an arrangement and a method for a so-called ideal acoustic ringing of bells, no supporting moments being introduced into the supporting structure according to the invention and lateral thrust forces generated by the vibrating bell or the unbalance caused by it being completely compensated for. Imprecise bobbin lace is also prevented. The transmission of structure-borne noise from the bell to the supporting structure and the masonry is also prevented without the acoustic properties of the bell being impaired.

These three effects are directly interdependent; d. that is, the side shear forces influence the bobbin stops and the transmission of structure-borne noise to the structure and the masonry. Precise bobbin stops are also realized by fully compensating the sideshift caused by the bell movement; The structure and masonry are not exposed to vibrations. The formation of cracks in the masonry, which can lead to the destruction of the masonry, is avoided.

In addition to the elimination of the technically serious problems mentioned above, the use of the invention means that all bell experts want and get the required acoustic benefits. The counter-pendulum ringing system decoupled by the drive mechanically according to the invention ensures that the energies and moments introduced during ringing and ringing are used to drive the counter-pendulum and therefore do not act on the supporting structure.

The invention provides a counter pendulum ringing system which uses a linear motor integrated into the ringing system as the ringing drive; by the transmission of the torque generated by the linear motor to the counter pendulum and from it via the pivot axis common to the bell, on which the counter pendulum hangs freely, after the third Newtonian axiom the action of the counter pendulum acts on the reaction of the bell except for an unavoidable bearing friction opposite. So that a complete compensation of the bell's action can be achieved, it is necessary that the at least one counter pendulum has the same mass and, based on the vertical axis of the bell, the same mass distribution as the bell.

Fig. 1

eine Vorderansicht einer über ein Joch auf einer Glockenachse aufgehängten Glocke, wobei die Glockenachse beidseitig jeweils ein gegenüber der Glockenachse frei schwingendes, jeweils von einem Linearmotor angetriebenes Gegenpendel trägt,

Fig. 2

eine seitliche Ansicht eines höhenverstellbaren Gegenpendels,

Fig. 3

eine seitliche Ansicht eines Gegenpendellagerbocks (gegenüber Fig. 1 und 2 vergrößert dargestellt) mit einer Höhenverstellung und Befestigungsbohrungen zur Verbindung mit dem Gegenpendel gemäß Fig. 2 und

Fig.4

eine Vorderansicht einer weiteren Glocke, die von zwei Linearmotoren angetrieben wird.

The invention is explained in more detail below in exemplary embodiments. Show it:

Fig. 1

3 shows a front view of a bell suspended over a yoke on a bell axis, the bell axis carrying on both sides a counter-pendulum which swings freely with respect to the bell axis and is each driven by a linear motor,

Fig. 2

a side view of a height-adjustable counter pendulum,

Fig. 3

a side view of a counter pendulum bracket (opposite Fig. 1 and 2nd shown enlarged) with a height adjustment and mounting holes for connection to the counter pendulum according to Fig. 2 and

Fig. 4

a front view of another bell, which is driven by two linear motors.

A bell 1 ( Fig. 1 ) has a crown 2, which is fastened via straps 3 to a yoke 4, which in turn is connected to a pivot axis 5, so that the bell 1 swings together with the pivot axis 5. The pivot axis 5 is mounted on both sides via bearings 6, 7 in a bell chair (not shown here) which forms the support device for the bell 1.

Rods 8, 9, each of which carries a stand 10, 11 of a linear motor 12 or 13, are fixedly connected to the yoke 4 or only to the pivot axis 5 itself. The rotors 14, 15 of the linear motors 12, 13 are mounted on counter pendulums 16, 17 opposite the stator 10, 11.

The counter pendulums 16, 17 are each mounted on the pivot axis 5 via slide bearings 18, 19 of a counter pendulum bearing block, freely movable. By energizing the linear motors 12, 13 via electrical lines (not shown here), the counter pendulums 16, 17 are set into an oscillatory movement which, due to Newton's third axiom, leads to an opposite oscillatory movement of the bell 1.

The embodiment with two counter pendulums 16, 17 has the advantage over an embodiment with only one counter pendulum that the same moments act on both sides of the bell 1.

In order to compensate for any differences in friction in the bearings 18, 19 of the two counter pendulums 16, 17 and to achieve complete uniformity of movement of the two counter pendulums 16, 17 from the beginning, these can be connected to one another via a rigid connecting bracket 100, which, for example can be carried out cranked.

A counter pendulum 16 or 17 preferably has a bell-shaped shape 20 like the one in FIG Fig. 2 counter pendulum shown. The mold 20 has a recess 21 for receiving a stator or rotor 22 of a linear motor. Via slots 23, 24, the form 20 is fastened to a counter-pendulum bearing block and the pivot axis 5 in a height-adjustable manner. In addition, holes 25, 26 are provided for receiving an additional weight in order to adjust the mass and the inertia tensor to a suitable balance with respect to the mass and the inertia tensor of the bell 1.

A form 27 ( Fig. 3 ) represents a counter pendulum bearing block, which has an essentially U-shaped structure. The two U-legs 28, 29 are connected to one another via a connecting bracket 30. The counter pendulum bearing block is equipped with a counter pendulum slide bearing 31 and a height adjustment 36, 37 formed by two elongated holes. Holes 32 and 33 are used to fasten the connecting bracket 100 (see. Fig. 1 ). Bores 34, 35 are provided for fixing the counter pendulum 20. The plain bearing 31 is between the axis 5 (s. Fig. 1 ) and a bronze ring 38 which is firmly connected to the inside of the connecting bracket 30 via a steel ring 39. The material bronze was chosen to create a material inequality between the axis 5 and the ring 38. If the axle 5 is made of steel, the ring 38 wears out faster than the axle 5 due to the sliding friction and can then be replaced. However, it goes without saying that both the axis 5 and the ring 38 can also be formed from a different, in particular harder material; other bearings, such as ball bearings, can also be used, for example.

In a further embodiment of the invention it is provided that a bell 1 ( Fig. 4 ) like the one in Fig. 1 Bell 1 shown is also equipped with two counter pendulums 16, 17, but that a linear motor 12 is only provided on the side of counter pendulum 16, in which case counter pendulum 16 carries a stator 40 of linear motor 12, while a rotor 41 on the rod 8 is attached.

Instead of the linear motor 13 ( Fig. 1 ) according to this embodiment of the invention, a linear motor 42 is provided, the stand 43 of which is attached to the upper side of the belts 3, in particular screwed to them. Alternatively, the stand can 43 also attach in a different way to the top of the yoke 4. The rotor 44 of the linear motor 42 is arranged on the underside of the connecting bracket 100.

In another alternative, not shown here, only a single linear motor is provided in the area of the connecting bracket 100.

According to the invention, a counter-pendulum system is created by the arrangement of two pendulum weights to the right and left of the bell, which are rotatably mounted on the same axis.

If a linear drive is attached to at least one of the two free-swinging pendulum weights or the connecting bracket (it is irrelevant for the function whether the stand and rotor are attached to the pendulum part or the bell), the counter-pendulum ringing system according to the invention is decoupled from the drive.

When using two height-adjustable counter pendulums, all side shear forces are eliminated without changing the historical design of the bell together with the clapper and the wooden or steel axis.

By using two height-adjustable pendulums in the form of disks and their slide bearing unit, as in Fig. 2 or 3 are shown, with a connecting bracket that is guided above the bell and axis and the (possibly already existing) linear drive motor (as it is state of the art), is achieved with this design that an unchanged bell sounds its ideal acoustics, with simultaneous removal of all side thrust forces and the resulting problems.

Due to the lack of evasive moments in the bell, precise bobbin stops are possible with this construction. The back vibrations of the structure or the towers are eliminated as well as energetic influences of other bells installed in the tower, which also leads to more precise attacks. This enables the desired protection of historical bell substance as it is is sought. Due to the lack of side shear forces, it is possible to attach the bell supports elastically and thereby avoid structure-borne noise.

Apart from the pendulum, the plain bearing block and the pendulum bearing, all mechanical additional components and the resulting energy losses due to friction with the associated noise are also eliminated. Noises and energy losses caused by side thrusts on the structure are also reduced considerably.

The mechanically decoupled counter pendulum ring system optimally uses the energy fed in to convert it into swing and sound frequencies. Minimal energy conversions in bearing friction (bell bearing / counter-pendulum bearing) lead to a stable, synchronous interplay of the system with the alternating swing and the energy fed in at zero crossing (bottom dead center) of the stator and rotor of the linear motor. Due to the angular spread during operation (stator and rotor move away), there is protection against overshoot or equilibrium of the system. It is thus possible to ring a bell ideally acoustically without changing the basic structure and to eliminate the above-mentioned essential problems of the conventional bell suspension, even in the tightest of spaces.

Claims (11)

Arrangement equipped with a counter-pendulum device for ringing a bell (1) suspended in a bell axis (5), characterized in that the counter-pendulum device comprises at least one counter-pendulum (16, 17) which is freely oscillating with respect to the bell axis (5), and that the at least one counter pendulum (16, 17) can be driven by at least one linear motor (12, 13: 42). Arrangement according to claim 1, characterized in that the at least one counter pendulum (16, 17) or a bracket (100) connected to the at least one counter pendulum (16, 17) the stator or rotor (10, 11; 40 or 14, 15 ; 41) of the linear motor (12, 13). Arrangement according to claim 2, characterized in that the stator (10, 11; 40) or rotor (14, 15; 41) of the linear motor (12, 13) is attached to the at least one counter pendulum (16, 17) and the rotor ( 14, 15; 41) or stand (10, 11; 40) of the linear motor (12, 13) on a bracket (8, 9), which can be pivoted together with the bell (1) and is rigidly connected to the bell axis, in the vicinity of the Counter pendulum (16, 17) is attached. Arrangement according to one of claims 1 to 3, characterized in that a counter pendulum (16, 17) is arranged on either side of the bell. Arrangement according to claim 4, characterized in that the two counter pendulums (16, 17) are connected to one another via a bracket (100). Arrangement according to claim 5, characterized in that a linear motor (42) is arranged in the area of the bracket (100), the bracket (100) carrying the rotor (44) or the stator of the linear motor (42) and the stator (43 ) or the runner on an upper element of the yoke (4) Bell (1) or on the top of the bell (1) with the yoke (4) connecting bands. Arrangement according to one of Claims 1 to 6, characterized in that the at least one counter pendulum (16, 17) is designed as a physical pendulum, the mass distribution of which on the vertical axis corresponds to the mass distribution of the bell (1) on the vertical axis. Arrangement according to claim 7, characterized in that the at least one counter pendulum (16, 17) is height-adjustable relative to the axis. Arrangement according to one of claims 1 to 8, that it has at least one receiving device for receiving an additional weight. Arrangement according to one of claims 1 to 9, characterized in that the at least one linear motor (16, 17) is connected to an angle sensor which determines the angular position of the bell (1) and that the linear motor (16, 17) by a control device in Depending on the angular position of the bell (1) can be driven. Method for ringing a bell (1) using an arrangement according to one of Claims 1 to 10.

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