Drives and Controls Magazine

Adaptable coupling slashes spares costs

09 May, 2007

A German couplings specialist, Gerwah, has come up with a shaft connecting system that, it claims, will avoid the need to stock a wide range of connectors and keys to cope with emergencies. The company’s Smart-Lock system covers shaft diameters from 25–65mm in just eight sizes.

Gerwah coupling exploded

The system (shown above and below) uses cylindrical sleeves with untreated forged surfaces that adapt to different shaft diameters. After they have been inserted into hollow shafts, and secured using shrink discs, the sleeves are said to guarantee precise fits, without any free play.

Gerwah coupling diagram

The system is designed to overcome the problems of connecting shafts that have been subject to fretting, corrosion and excessive wear. These can lead to slipping and other problems unless the precise connector size is available.

"We had been looking for a solution that is indifferent to size tolerances, but can be adapted to various solid- and hollow-shaft diameters," explains Gerwah’s managing director, Gerd Schuessler. He says that that the new system will provide a cost-effective connection, "even in the case of previous wear".

The adapters are also available in imperial measures for countries that do not use metric measurements.