Linear Motors Break Through Silence

Baumüller drives make the bells of the Protestant St. Nicholas and Ulrich Church in Nuremberg-Mögeldorf ring

For two years it was quiet in the Protestant church community of St. Nicholas and Ulrich in Nuremberg-Mögeldorf. No bells could be heard far and wide. This was due to the unstable roof structure of the church, which was reconstructed last year. Thanks to the linear drives of the company Baumüller, which is headquartered just two kilometers from the church, the bells are now ringing again.Abb1 GlockenantriebUsing linear motors from the company Baumüller, the church bells in Nuremberg-Mögeldorf are back in operation. The motor’s narrow design makes it easy to attach it to the belfry right next to the bell

A Unique Sound

The top of the hour has been reached in Mögeldorf. A soft hum in the belfry precedes the loud chimes, which announce the time. With the humming, the two church bells begin to swing and ring: Ding-dong, ding-dong. The reverend Ulrich Bauer-Marks smiles saying, “It's nice to hear that sound again after two years of silence.”

Linear direct drives were used instead of the conventional solution, i.e. using three-phase motors combined with mechanical transmission elements. They are impressive due to their narrow design and a jerk-free ringing. In addition, they allow for a particularly beautiful sound, since the bells are rung without contact via induction forces.Abb2 JochTwo bells with asynchronous linear motors from Baumüller provide the unique sound in the Mögeldorf church in Nuremberg

The asynchronous linear drives are maintenance and wear-free and are only six centimeters wide each. The assembly on the belfry directly next to the bell is simple, since this solution does not have any moving components, such as chains or gear belts. The drives power develops near the bell's axis of rotation, thereby only generating small vibrations, which is accommodated by the tower structure's weight bearing.Abb3 Mögeldorfer KircheBaumüller linear direct drives only generate small vibrations, which are absorbed by the tower structure of the 600 year old Mögeldorf church

25 Years of Expertise in Bell Chime technology

In 1993, the company Schmidt Glockentechnik introduced this type of bell chime technology with linear drives from Baumüller. Each linear motor consists of a motor and a reaction rail. The motor corresponds to the stator and the reaction rail corresponds to the rotor of a three-phase drive. The reaction rail is secured to the bell's hoke, which is a rotatable beam.

A magnetic field is required to put the bell into motion. The motor generates this magnetic field and also induces another magnetic field in the reaction rail. These opposing magnetic fields attract and repel each other, thus putting the bell into motion. It begins to swing and rings.

The Mögeldorf bells were cast in the 16th century and are well-preserved. The large bell weighs 930 kilograms and the small bell weighs 262 kilograms.