Techdrives is promoting the Moenninghoff metal disc shaft couplings that it supplies, covering shaft sizes from 4 to 120mm and torques up to 9000Nm. The use of standard modular components to suit different configurations makes these couplings cost-effective and readily available, often from stock. Metal disc couplings benefit from an all-metal construction, which makes them robust and maintenance-free. The inherent properties of high torsional stiffness and a lack of backlash means they are suitable for precision and positioning drives. Customised spacer versions can be supplied with up to 5m separation between the shaft ends.
The key component in a metal disc coupling is the disc pack – a pre-assembled sandwich of stainless steel laminations held together by bushes at four or six positions. These laminations flex between the bolts to accommodate misalignment. A single flexing coupling has one disc pack and suits applications where there is no parallel misalignment - for example, where one of the shafts is floating in a single bearing. More usually double-flexing couplings are used where a central spacer bolted to the two disc packs allows for parallel as well as angular and axial misalignment. Fitted bolts are used to connect between the external hubs and the disc packs/spacers to make the assembly backlash-free. As an alternative to keywayed connections, which may introduce slight backlash, clamp hubs are available.
Metal disc shaft couplings can transmit high torques at high speeds, with power ratings potentially extending into thousands of kilowatts. At the other extreme they are suitable for encoder drives because of their high torsional stiffness. They offer a maintenance-free alternative to universal, grid and gear couplings. Ideally angular misalignment should be below 0.5 degree but up to 1 degree or more is possible with de-rating. High ambient temperatures are generally not a problem.
Alloy and steel
Mönninghoff's range begins with miniature single- and double-flexing couplings rated at 1Nm for shafts of 4-8mm diameter. These tiny couplings are supplied preassembled with aluminium alloy hubs. Thirteen models are available with the alloy construction but, for shafts from 8mm diameter, there is also steel construction. Metal disc couplings with steel hubs and spacers are supplied in component form. Standard options include short and long central spacers, as well as clamp hubs.
Techdrives says that Monninghoff has a well defined range of metal disc couplings with modular options to suit many diverse requirements. This keeps costs low and delivery times short. They are proven across a wide range of applications, for example keeping accurate registration on a printing machine, surviving the arduous conditions in steel production and ensuring precision with instrument drives. Here the big benefits are the high torsional stiffness, lack of backlash and a zero maintenance requirement. Follow the link for more information about metal disc shaft couplings from Techdrives.