Ruland Manufacturing's oldham couplings accomodate large amounts of parallel misalignment. Applications for oldham couplings include encoders, positioning systems using servo and stepper motors, as well as other light duty drives. Possible other applications include anything where easy component removal for cleaning is desired. In higher rpm applications, the couplings feature a balanced design for reduced vibration. Oldham couplings are a three-piece design comprised of two hubs and a floating center disc. According to Ruland's press release, the center disc is available in acetal for high torsional stiffness or nylon for shock absorption and vibration dampening, and 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, are on opposite sides of the disc and 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. Couplings can 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 parallel offset capabilities,oldham couplings accommodate small amounts of angular misalignment and axial motion.