19 Jul 2024

Electric motors with integrated safety coupling

ELIN Motoren and Voith launch electric motors with integrated safety coupling for the reliable and maintenance-free operation of tunnel boring machines

ELIN Motoren and Voith have announced they have launched the first electric motor with integrated safety coupling for the main drive of tunnel boring machines.

Water-cooled asynchronous motors from ELIN Motoren contain either the Voith SafeSet to safeguard the entire drive train or the Voith SmartSet for continuous operation, even with frequent torque peaks. Torque limitation increases the productivity of the TBM, protects the machine components, and avoids costly downtimes.

Depending on size and geology, the cutting head of a TBM is powered by between four and 24 drive units. These drive trains consist of a pinion, planetary gear unit, torsion shaft, safety coupling, and electric motor and represent the heart of a TBM that should be protected. Clogging in the cutting head causes a sudden torque much higher than the maximum permissible torque with which the drive train is rated. As it is activated at a predefined torque, the integrated safety coupling in the new MKH-SafeSet and MKH-SmartSet electric motors from ELIN Motoren accurately and reliably protects all the drive train components of tunnel boring machines. A triggered coupling can be re-activated within just a few minutes. If only a few couplings are released, the TBM can continue to tunnel until the next maintenance shift.

The weight of the new Voith SafeSet has been reduced by more than 80% and is only around 15% of that of conventional safety couplings. A lower mass minimises rotor inertia and the bearing loads of the drive train, which improves efficiency and achieves lower temperatures, thus extending the service life of the drive train.

The MKH-SmartSet is an optional add-on to the MKH-SafeSet and allows continuous tunnelling despite any torque peaks that are non-critical for the drive train. Adding a SmartSet results in an automatic reset if the TBM slows down or comes to a stop which allows continuous operation, even if the frequency of high torque load peaks increases, which positively affects the productivity of the TBM.

“Partnering with ELIN Motoren, we have a powerful new to-the-market technical solution that will transform the tunnelling boring market segment,” confirms Per-Olof Berg, Product Management Torque Limiting and Connection Couplings at Voith and adds: “The new MKH-SafeSet and MKH-SmartSet is a further development of the well-known SafeSet portfolio which is in operation on thousands of ELIN Motoren cutter head motors. The new MKH-SmartSet instantly shaves the torque peak and protects the drive without releasing. Furthermore, MKH-SafeSet, with the coupling integrated into the cutter head motors from ELIN Motoren, is the perfect lightweight and compact solution for tunnel boring machines that do not need peak shaving and automatic resetting.”

“The pooling of the expertise of ELIN Motoren and Voith offers manufacturers of tunnel boring machines a powerful yet safe technical solution from a single source,” says Markus Frickh, Key Account Manager at ELIN Motoren. “As a manufacturer of customised electric motors, we aim to offer products that meet the stringent individual requirements in the mechanised tunnelling segment.”