Oldham Couplings for High Misalignment

Ruland Manufacturing Co., Inc. offers oldham couplings that accomodate large amounts of parallel misalignment. Applications for oldham couplings include encoders, positioning systems using servo and stepper motors, and other light duty drives. They are also useful in applications where easy component removal for cleaning is desired. In higher rpm applications, the couplings feature a balanced design for reduced vibration.

Oldham couplings have a three piece design comprised of two hubs and a floating center disc.  The center disc, which is available in acetal for high torsional stiffness, or nylon for shock absorption and vibration dampening, is the torque transmitting element.  Torque transmission is accomplished by mating slots in the center disc with the drive tenons on the hubs.  The slots fit with a slight press fit and are on opposite sides of the disc and are oriented 90 degrees apart.  The press fit allows the coupling (with acetal disc) to operate with zero backlash.  In operation, the center disc slides on the tenon of the hub to accommodate misalignment.           

There are many advantages to oldham couplings, but its most distinctive feature is the ability to accommodate large amounts of parallel misalignment with light bearing loads.  This is especially important for protecting delicate bearings or seals and in applications where it is not practical to closely control parallel misalignment during the assembly process.  In addition to the large parallel offset capabilities, oldham couplings accommodate small amounts of angular misalignment and axial motion.  Oldham couplings also have the advantage of electrical isolation, relatively low cost, and mechanical fuse properties – since the coupling disengages if the replaceable center disc breaks.             

Ruland oldham couplings are offered in seven sizes of set screw or clamp style hubs with bores from 1/8” to 2 ¼” (57mm).  The hubs are anodized for improved lubricity and increased life.  The couplings feature a balanced design for reduced vibration in higher rpm applications.  Common applications for oldham couplings included encoders, positioning systems using servo and stepper motors, and other light duty drives.  They are also useful in applications where easy component removal for cleaning is desired.            

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