Steel Giant Switches to rubber-in-compression couplings


Steel giant, Corus, has replaced all the couplings on the main hoists of its huge, 500-ton ladle cranes at Port Talbot with rubber-in-compression couplings, from Renold Hi-Tec, following successful trials. The company began testing rubber-in-compression couplings several years ago in an attempt to reduce vibratory torque and increase coupling life on lifting applications. The couplings performed so well that Corus is now in the process of replacing all the other couplings on its cranes with rubber-in-compression couplings to increase coupling life, control vibration and reduce maintenance.

Rubber-in-compression couplings are made up of two round, metal sections fitting one inside the other, with what looks like the paddles of a paddle steamer projecting inwards from the outer section and outwards from the inner. Rubber blocks are placed in the spaces in-between the paddles, and as the outer section is turned it drives the inner section through the rubber blocks. As this happens the rubber is compressed, hence the term 'rubber-in-compression.'


As well as reducing vibratory torque, the rubber-in-compression couplings are also maintenance free and do not require lubrication or adjustment of any kind, which means that they provide the lowest lifetime operating cost compared to alternative couplings that require regular maintenance.

Following its successes at Port Talbot Renold Hi-Tec Couplings has also received an order from Ipsco Steel, of Canada, for 30 PM rubber-in-compression couplings for use on its tap and scrap cranes in its melt shop.