Oldham coupling

An Oldham coupling is a three-piece flexible shaft coupling used in mechanical power transmission assemblies. It consists of two hubs and a middle disc, with the hubs attached to the input and output shafts, respectively. The middle disc is joined to the hubs by tongue and groove joints, which are perpendicular to each other Oldham couplings are popular for stepper-motor driven positioning stages. The flexible element can provide an effective means of absorbing shocks from frequent start/stops and load reversals; its plastic central disc also offers electrical isolation. The element can be installed with some clearance between the hubs to compensate for axial growth. Generally, Oldham couplings are recommended for intermittent motion systems that are idle at least half the time. Both blind-bore and through-hub styles are available, the latter being capable of mounting to driving and driven shafts without displacing the equipment or disturbing shaft alignment 1.Bore size or diameter – the diameter of the coupling bore that accepts the connecting shaft. Bore sizes may be identical or different on each side of the coupling, depending on the model. 2.Overall length – the end-to-end length of the coupling as measured from the two end faces of the coupling. 3.Hub width – the width of the hub measured from the end face to the internal face of the tooth that joins the slider block. 4.Hub material – the material from which the hub is constructed. 5.Slider block material – the material from which the slider block is constructed. 6.Coupling diameter – the overall diameter of the coupling. 7.Maximum rated torque – the maximum rating of the coupling for peak torque rating. 8.Lateral offset – also called parallel misalignment, represents the maximum tolerable distance of shaft misalignment along the axial dimension that can be accommodated by the coupling. 9.Angular offset – also called angular misalignment, represents the maximum angular deviation of shaft misalignment along the