MRO Magazine

Oldham couplings: Not just for motion control applications


May 12, 2011
By PEM Magazine

Oldham couplings are typically used in motion control applications where zero-backlash performance is required. However, these couplings, such as those from Ruland Manufacturing Co. Inc. (pictured, distributed in Canada by RotoPrecision Inc.), are increasingly used as an alternative to straight jaw couplings on general industrial equipment such as pumps, valves, gearboxes, and conveyor systems due to their versatility, ease of assembly, and extended life if misalignment is present.

The oldham coupling is a three-piece assembly comprised of two anodized aluminum hubs and a torque transmitting center disk. This design results in a highly customizable shaft coupling which can easily interchange inch to metric, different bore dimensions, and keyed shafts. The center disc is available in acetal plastic for high torsional stiffness and zero-backlash, or nylon for shock absorption and noise reduction. Ruland offers numerous standard bore combinations from 1/8 inch (3 mm) to 1 inch (30 mm) with hubs also available in stainless steel.

Industrial equipment manufacturers can benefit from oldham couplings in place of straight jaw couplings thanks to their ability to accommodate parallel misalignment, act as a mechanical fuse, and be electrically isolating. These key features promote a very light bearing load, stop transmission of power during overload, and minimize damage to more expensive machinery components. The three piece design of the oldham coupling allows for ease of installation. Blind assembly can be achieved by independently installing the hubs and mating their drive tenons to the slots on the center disc. 

Oldham couplings are part of Ruland’s complete product line which includes shaft collars, rigid couplings and five types of zero-backlash motion control couplings: beam couplings, bellows couplings, oldham couplings, disc couplings, and curved jaw couplings.