Ringfeder Power Transmission has developed a patent-pending engine coupling that optimizes torsional stiffness and misalignment tolerance across a wide torque range. This new Tschan TNR coupling is intended primarily for mobile and stationary diesel-driven powertrains. These couplings consist of an aluminum housing and steel hub separated by one or two rows of mechanically-linked, cylindrical elastomer inserts. These inserts undergo a controlled deformation under shear loads as the coupling transmits torque.

Fine-tuning the torsional stiffness and misalignment tolerance of a given TNR model requires only minor changes to the composition of the elastomer—with 'stiffer' inserts favoring torque transmission efficiency and 'softer' inserts favoring misalignment tolerance. The TNR's ability to deliver precisely tuned dynamic stiffness can help solve resonance and vibration problems. Compared to traditional rubber motor shaft couplings, the TNR weighs about 20 percent less for a given coupling size.  It offers a 15 to 20 percent lower cost of ownership owing to the ease of replacing the elastomer inserts. The Tschan TNR series covers a torque range from 160 to 68,000 Nm and speeds up to from 6,000 rpm.