Hydrodynamic coupling locks at speed to avoid slip

Tom Shelley reports on a development that eliminates slip in a hydrodynamic coupling and saves a significant amount of energy. By adding swinging elements that can lock a hydrodynamic coupling, it has been found possible to reduce energy and/or increase output by about 3 per cent in a coal mill and up to 10 per cent for fans. The crucial device has been designated by makers, Voith, the 'TurboSyn', because it is able to synchronise input and output speeds. The basic design is similar to that of conventional Voith turbo couplings, except that the inner element is made up of rotating segments. These segments swivel to engage the outer element as a friction drive once the machine has been accelerated hydrodynamically. One of the devices, a model 750 TV-SYN, has been proven on a coal mill at the Frimmersdorf coal fired power station in Germany, eliminating slip, said to usually be around 3 per cent. The result of two years development work, the TurboSyn has been patented world wide. Applications are seen for starting up single drives in mills, fans, pumps and belt conveyors. Voith Turbo Email product manager Klaus Maier