The product group Startup Components developed a high-performance and slip-free 10 MW coupling combination (Type 1210 TPL-SYN) in order to increase efficiency of drives in big mills of the cement and minerals processing industry.

American companies prefer synchronous motors in the drives of tube mills. They provide slip-free operation and the possibility to

compensate wattles current which saves considerably energy expenses.

Ball mills, however, require high torque for starting. Thus torque has to be uncoupled between the synchronous motor which is not capable to start under load and the mill.

Voith already could present the superior properties of hydrodynamics for start-up and gear shifting by means of the fill-controlled Voith Turbo fluid coupling in several plants in the USA, Mexico und Chile, where high-speed synchronous motors are used. These couplings, however, were designed to minimum nominal slip, but not to required performance, thus resulting in bigger sizes. But the customer criticized the energy losses due to the physic-specific slip. On request of and in close cooperation with the American cement industry and leading mill manufacturers Voith Turbo now proceeded in developing a coupling combination combining the benefits of hydrodynamics during start-up with slip-free nominal operation. Thus a self-supported start-up fluid coupling came into being, including an integrated oil supply system and a mechanical lock-up device to bridge possible slip.

To do so, Voith combined its know-how as to hydrodynamics with knowledge and experiences gained from Voith products of familiar manner. The power range of this new coupling type reaches up to 7 MW at 1,000 rpm and 9 MW at 1,200 rpm in the case of mills and 7 MW up to 12 MW at 1,200 rpm in the case of fans.

An “electronic brochure” with several animations and video clips of the 1210 TPL-SYN coupling is available on CD-ROM.