When precision machine drives are assembled without mounting pilots between the servo motor/gearbox and driven equipment, shaft misalignment becomes a key consideration in coupling selection.
Most precision couplings are designed to compensate for a parallel shaft misalignment of between 0.1-0.2mm, which is perfect for piloted interfaces. When the connected components are mounted to different surfaces, however, it is often better to have a little more flexibility. This is where servo disc couplings can be an excellent choice.
Fully metallic and able to transmit motion with zero-backlash and high torsional stiffness, servo disc couplings are wear and maintenance-free, while providing more misalignment compensation. The flexible elements are made up of layers of sheet steel that are assembled into disc-packs and fastened to the adjacent hub components in multiple alternating locations. This allows the individual disc packs to accommodate an angular bend while rotating. Two disc-packs mounted inline can then combine to complete the offset needed to compensate for parallel shaft misalignment.
Individual couplings with a single disc pack can also be very useful for supporting various intermediate components such as torque meters and drive shafting between them. This is because the single flex allows for an angular bend while remaining stiff in shear. Consequently, the intermediate component is held firmly within its rotational axis while the combination of the two single flex couplings at each end of the assembly helps to ensure smooth operation without misalignment loading.
R+W SCL Series Servo Disc Couplings at a glance:
· Larger misalignment tolerances than other servo couplings
· Wear and maintenance free
· Fully metallic and temperature resistant
· Available in dual or single flex configuration
· 4 sizes with torque capacities ranging from 25 to 100 Nm
· Inch and metric bore diameters ranging from 5/8-in. up to 40mm