EP3624110B1 - Drive for a bell and method for ringing a bell - Google Patents

Description

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

Bells are set in a pendulous motion to ring. In the steady state, a clapper, which is suspended in the middle of the bell, strikes the brass knuckles of the bell rib. The bells are usually hung in towers, especially 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 act periodically on the tower with the pendulum frequency of the bell. This then leads to a critical condition when the natural bending frequency of the bell tower corresponds to the pendulum frequency of the bell or a multiple thereof. Cases in which the natural bending frequency of the bell tower coincides with the basic frequency of the pendulum movement of the bell or a multiple, occur again and again.

However, bells are generally rung with a relatively large ringing angle, which is usually between 50 ° and 80 °, in some cases even more. Due to the geometric non-linearity, the bearing forces also contain components with multiples of the pendulum frequency, ie higher harmonics. The horizontal bearing forces contain odd multiples of the pendulum frequency, while the vertical bearing forces only contain even multiples of the pendulum frequency. In addition to the horizontal bearing forces, with eccentric bell bearings, the vertical bearing forces also lead to horizontal displacements 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 the formation of cracks or even to the destruction of the tower. This phenomenon is known per se. A number of solutions have been suggested to overcome this problem.

the end DE 238 392 C and DE 249 776 C arrangements for canceling the side forces of swinging bells by means of counter pendulums have already become known. While according to DE 238 292 C it is provided that the same static moment of the counter-pendulum oscillating synchronously and in opposite phase is achieved with the smallest mass of the counter-pendulum DE 249 776 C discloses a counter pendulum swinging against the bell, the mass of which should be compressed around the center of oscillation in such a way that it should be possible to accommodate the counter pendulum in the spaces between the bell and the bell cage linkage.

Even AT 35 162 B and AT 3465 U1 each disclose a ringing device with a counter pendulum which, viewed 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 oscillation axes of the bell and the counter pendulum coincide, the forces of the bell and the counter pendulum do not compensate in the bell cage, but directly in the same axis. Supporting counter-forces of the motor or reverse gear are introduced into the structure.

On the other hand are out DE 44 36 905 A1 a method and a device for controlling an oscillating load driven by a linear motor, so for example a bell, known with a linear motor that works without a power transmission via cables to the bell, by a linear motor its drive torque via a firmly connected to the bell yoke Reaction rail transfers to the bell. The supporting moment is introduced into the structure.

DE 39 25 967 C2 also discloses an electric bell ringing drive with a linear motor.

With the known procedures, the technical problems of ringing bells could only be solved in an imperfect way. When bells ring, side thrust forces are generated which are transmitted from the bell cage to the masonry of the tower.

An ideal acoustic ringing, as it is desired by the bell experts in Central Europe, although the ringing habits are different, results when the bell is ready for operation with full mass, hung below its axis pivot point. After deducting the mass of the steel or wood axis, the result for the bell is a mass distribution of approx. 90% to 10% for the steel or wood axis. With an 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 the sound excitation of the bell when the bell rises, freely swinging at full pitch. Regularly changing angular velocities result in a regularly changing Doppler effect.

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

Structural dynamics, structural engineers and DIN 4178 therefore require that only a small amount of sideshift is permitted and that the oscillation 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 failure of the system consisting of bell and clapper.

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

According to this knowledge of the problem, the acoustic demands of the bell experts and the technical demands of the structural engineers when building bell ringing systems are not compatible with each other.

In exceptional cases, counter-pendulum systems are installed to eliminate the sideshift problem, in which a counter-oscillating pendulum cancels the sideshift forces, as in the one mentioned above AT 3465 U1 is described. These counter pendulum systems eliminate the sideshift problem as far as possible, but again have several disadvantages; In addition to the bell drive, they take up additional space and require complex production and reconstruction of the supporting structure. Supporting forces are still introduced into the tower structures in these structures.

The use of gear wheels or cable gears creates additional problems: imprecisely set counter pendulums result in imprecisely defined clapper stops. Due to the play of the gears or the rope, the clapper is opposed to a changing flywheel when it hits the free-swinging bell at the upper turning point. This is the ideal weight design of the clapper to the bell weight, as it is for example in Conference report on the 2nd ECC-ProBell Bell Symposium from March 21-22, 2018, edited by Andreas Rupp, Michael Plitzner, Göttingen, 2018, 1st edition , is required, not possible.

The side thrust forces of the bells, as well as unclean clapper stops, require a rigid attachment of the bearings. However, in connection with additional mechanical noises, this leads to strong structure-borne sound transmissions into the masonry of the tower and in the nave. The additional mechanical components lead to a stronger feed-in of energy in order to keep the more sluggish and heavier ringing system at the set ringing angle. As a result, the supporting torques of the drive machines and gears described at the beginning also increase.

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

This object is achieved according to the invention, as stated in claim 1. Advantageous further developments of the invention emerge from the subclaims and the description, in particular in connection with the drawings.

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

The stator or rotor of the linear motor is preferably attached to the at least one counter pendulum, and the rotor or stator of the linear motor is attached near the counter pendulum on a bracket that is pivotable together with the bell and rigidly connected to the bell axis. By combining the counter pendulum with the drive, the counter pendulum comprising part of the drive, a construction that is very compact compared to the prior art, in the form of a direct drive without a reduction gear, is made possible.

An arrangement according to the invention with a bell does not affect other bells, so that in these no undefined clapper stops such. B. bouncing blows 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 knocked out or destabilized by the undesired vibrations of bells that have been transferred to the tower is stabilized again by the additional weight. By using the invention, simpler supporting structures of the tower and / or the bell cage 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 both sides of the bell, at least one of which carries a stator 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 axle to the smallest possible space.

In order to compensate possibly existing differences in the bearing friction, the two counter pendulums are connected to one another in one embodiment via a bracket. Alternatively, linear motors can be present as drives on both sides of the bell or on the connecting bracket, which are fully 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 a 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 cheaper but lower density 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, a further advantageous embodiment of the invention provides that the at least one counter pendulum is height-adjustable relative 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 in order to achieve a steady state after the ringing process or at which bell exit 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 so-called ideal acoustic ringing of bells, whereby according to the invention no supporting moments are introduced into the structure and the side thrust forces generated by the vibrating bell or the imbalance caused by it are fully compensated. Imprecise bobbins are 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 related to one another; d. In other words, the lateral thrust forces influence the clapper stops and the transmission of structure-borne noise to the structure and the masonry. By fully compensating for the sideshift triggered by the bell movement, precise clapper stops are also achieved; The structure and masonry are not exposed to any 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, all of the bell experts desired and desired by the use of the invention Obtain the required acoustic advantages. The drive-mechanically decoupled counter pendulum bell system according to the invention ensures that the energies and moments introduced when the bell is rung and raised are used to drive the counter pendulum and therefore do not act on the supporting structure.

The invention provides a counter pendulum bell system which uses a linear motor integrated into the bell system as a bell drive; By transferring the torque generated by the linear motor to the counter pendulum and from this via the pivot axis shared with the bell, on which the counter pendulum hangs freely, according to Newton's third axiom, the action of the counter pendulum acts on the reaction of the bell except for unavoidable bearing friction opposite. So that a complete compensation of the action of the bell can be achieved, it is necessary that the at least one counter pendulum has the same mass and, in relation to 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

a front view of a bell suspended via a yoke on a bell axis, the bell axis carrying a counter pendulum, each driven by a linear motor, which oscillates freely with respect to the bell axis,

Fig. 2

a side view of a height-adjustable counter pendulum,

Fig. 3

a side view of a counter pendulum bearing block (opposite Fig. 1 and 2 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 bell axis or 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 cage (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 and 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 to move freely on the pivot axis 5 via slide bearings 18, 19 of a counter pendulum bearing block. By energizing the linear motors 12, 13 via electrical lines (not shown here), the opposing pendulums 16, 17 are set in an oscillating movement which, based on Newton's third axiom, leads to an opposite oscillating 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 bring about complete uniformity of the movement of the two counter pendulums 16, 17 right from the start, they can be connected to one another via a rigid connecting bracket 100 which, for example can be cranked.

A counter pendulum 16 or 17 preferably has a shape 20 bell-shaped in cross-section, such as that in FIG Fig. 2 shown counter pendulum. The mold 20 has a recess 21 for receiving a stator or rotor 22 of a linear motor. Via elongated holes 23, 24, the mold 20 is attached to a counter pendulum bearing block and the pivot axis 5 in a height-adjustable manner. In addition, there are bores 25, 26 for receiving an additional weight in order to set a suitable balance of the mass and the inertia tensor with respect to the mass and the inertia tensor of the bell 1.

A shape 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 sliding bearing 31 and a height adjustment 36, 37 formed by two elongated holes. Bores 32 and 33 are used to attach the connecting bracket 100 (see Sect. Fig. 1 ). Bores 34, 35 are provided for fixing the counter pendulum 20. The slide bearing 31 is between the axis 5 (see Fig. 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 in order 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. It goes without saying, however, that both the axis 5 and the ring 38 can also be formed from another, in particular harder, material; for example, other bearings, such as ball bearings, can also be used.

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 the counter pendulum 16, in which case the counter pendulum 16 carries a stand 40 of the linear motor 12, while a runner 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 43 also fasten on the upper side of the yoke 4 in a different way. 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, the arrangement of two pendulum weights to the right and left of the bell, which are rotatably mounted on the same axis, creates a counter pendulum system.

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

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

Thanks to the use of two height-adjustable pendulums in the form of a disk and their plain bearing unit, as shown 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), this design ensures that an unchanged bell produces its ideal acoustics, with simultaneous cancellation of all lateral thrust forces and the resulting problems.

Due to the missing evasive moments of the bell, precise clapper stops are possible with this construction. The back vibrations of the supporting structure or the towers are eliminated as well as energetic influences from other bells built into the tower, which also leads to more precise stops. This enables the desired conservation of historical bell substance, like her is strived for. Due to the lack of lateral shear forces, it is thus possible to elastically attach the bell supports and thereby avoid structure-borne sound transmission.

Apart from the pendulum, the plain bearing block and the self-aligning bearing, all additional mechanical components and the resulting energy losses due to friction and the associated background noises are omitted. Noise and energy losses caused by side thrusts on the structure are also significantly reduced.

The drive-mechanically decoupled counter pendulum bell system uses the fed-in energy optimally 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 the 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 a safeguard against overshoot or equal swing of the system. It is thus possible to ideally ring a bell 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)

1. Arrangement equipped with a counter pendulum device for ringing a bell (1) suspended on a bell axis (5), the counter pendulum device comprising at least one counter pendulum (16, 17) which can be driven by at least one linear motor (12, 13; 42) comprising a stator and a rotor (10, 11; 40, 43 and 14, 15; 41, 44), characterized in that the at least one counter pendulum (16, 17) is mounted on the bell axis (5) in a freely swinging manner.
2. 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) carries the stator or rotor (10, 11; 40 or 14, 15; 41) of the linear motor (12, 13).
3. Arrangement according to claim 1, characterized in that the stator (10, 11; 40) or the rotor (14, 15; 41) of the linear motor (12, 13) is mounted on the at least one counter pendulum (16, 17), and the rotor (14, 15; 41) or stator (10, 11; 40), respectively, of the linear motor (12, 13) is mounted on a support (8, 9), which is pivotable together with the bell (1) and is rigidly connected on the bell axis, in the vicinity of the counter pendulum (16, 17).
4. Arrangement according to any of claims 1 to 3, characterized in that a counter pendulum (16, 17) is arranged laterally on each side of the bell (1).
5. Arrangement according to claim 4, characterized in that the two counter pendulums (16, 17) are connected to one another via the bracket (100).
6. Arrangement according to claim 1, characterized in that the linear motor (42) is arranged in the area of a bracket (100), wherein the bracket (100) carries the rotor (44) or the stator (43) of the linear motor (42) and opposite to it the stator (43) or the rotor, respectively, is mounted on an upper element of the yoke (4) of the bell (1) or on the upper side of bands connecting the bell (1) to the yoke (4).
7. Arrangement according to any of claims 1 to 6, characterized in that the at least one counter pendulum (16, 17) is designed as a physical pendulum whose mass distribution over the vertical axis corresponds to the mass distribution of the bell (1) over the vertical axis.
8. Arrangement according to claim 7, characterized in that the at least one counter pendulum (16, 17) is mounted in a height-adjustable manner relative to the axis.
9. Arrangement according to any of claims 1 to 8, characterized in that it comprises at least one receiving device for receiving an additional weight.
10. Arrangement according to any of claims 1 to 9, characterized in that the at least one linear motor (12, 13) is connected to an angle sensor which determines the angular position of the bell (1), and in that the linear motor (12, 13) can be driven by a control device as a function of the angular position of the bell (1).
11. Method of ringing a bell (1) using an arrangement according to any one of claims 1 to 10.

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