Type TDS / HPD Parallel Shaft Speed Reducers, are available with torque ratings up to 6,000,000 inch-pounds, and standard gear ratios up to 1500:1. TDS and HPD units incorporate precision helical gearing (in single, double, triple, quadruple and quintuple reductions) enclosed in heavy duty cast iron or welded steel housings. Type TDS units utilize through hardened gears and Type HPD units utilize case hardened and ground gears. Standard features include tapered roller bearings, large inspection plates, a positive splash system for lubrication, extra wide bearing spans and center bearing supports; all to provide a rugged, reliable unit with proven dependability in virtually every industrial application. Nuttall Gear can supply TDS and HPD units separately or in a completely engineered package including motor and reducer mounted on a bedplate.