MRO Magazine

Zero-backlash jaw couplings for optical inspection systems

December 8, 2015 - Stop-and-go optical inspection systems often have aggressive acceleration/deceleration profiles that generate vibration and high torque values. The dampening characteristics of Ruland zero-backlash jaw couplings reduce settling time and shock loads resulting in more accurate system performance and decreased component wear.


December 9, 2015
By PEM Magazine

Jaw couplings from Ruland are comprised of two hubs and an elastic insert referred to as the “spider.” Hubs are type 2024 aluminum for low inertia and have a balanced design for reduced vibration at high speeds. The spider is made of polyurethane, allowing for dampening of impulse loads, minimizing shock to the motor and other sensitive equipment. Spiders are available in three durometers that offer a range of misalignment, dampening, torsional stiffness and torque characteristics. Zero-backlash jaw couplings are highly customizable, allowing clamp or set screw hubs to be combined with inch or metric and keyed or keyless bores.
Ruland jaw coupling hubs are machined with a proprietary curved jaw profile that press fits with the spider, assuring zero-backlash operation. This profile concentrates forces to the center of the spider’s limbs, improving the effectiveness of the elastomer material. If the spider fails the jaws of the two hubs will engage and continue to transmit torque, allowing the application to be safely shut down for maintenance. The spider can then be replaced, restoring the full performance characteristics of the coupling.
Zero-backlash jaw couplings are part of Ruland’s complete servo coupling product line that also includes rigid, beam, bellows, disc and oldham couplings. Established in 1937, Ruland focuses on the design and manufacture of high performing shaft collars and couplings. All products are carefully manufactured in Ruland’s Marlborough, Massachusetts, USA, factory under strict controls using proprietary processes.

3D CAD files, full product specifications, and additional technical information, are available at