Smaller, faster and more powerful: the demands on components in advanced transmission systems are high. This particularly applies to shaft-hub connections in modern transmission technology, for example in applications with backlash-free synchronous transmissions powered by compact servo- or multiphase motors, where positioning is critical. Conventional joints with keyways, grub screws and simple bushing do not guarantee zero backlash in such precision applications.

For these situations Ringfeder Power Transmission, with its RfN 7070 and RfN 7075 models, offers two locking assemblies with a central nut, which makes the grooving of hubs and shafts redundant. And what is more, they can be quickly and easily mounted. For mounting toothed belt discs, as well as cog wheels and sprockets on drive shafts, the locking assembly is first positioned on the hub and then on the shaft. Following this it is only necessary to tighten the safety nut to the required tightening torque. In this way, exact axial and radial positioning of the parts is possible in a matter of seconds, with the user also benefiting from significant time savings.

In contrast to conventional feather-key connections, where the torque load is largely transmitted in the area around the keyway, the self-centring locking components from Ringfeder provide even contact pressure to ensure a secure fit on the shaft. The connection also scores highly because it can be dismantled with minimum effort. For example, the locking element can be released easily from the shaft, even after years of operation.

The advantageous ratio of bore to outside diameter also ensures compact dimensions and appropriate savings in materials. This makes the new locking assemblies ideal for mounting on thin-walled structures. The excellent concentricity and balance of the key-less shaft-hub connection guarantee perfect running accuracy. The low mass moment of inertia and light weight also ensure optimal dynamic performance.