Reulands fluid drive coupling delivers stepless, smooth acceleration. This two-element device is comprised of a radial vane housing enclosing one or more radial vane runners immersed in oil. As the housing rotates, oil is forced against the runner vanes. This action spins the runners and the attached output shaft. The inherent slip characteristics of the fluid coupling allow motors to start nearly free of load and to accelerate the load to maximum torque.
Fluid couplings can provide many distinct advantages. Fluid couplings cushion the shock from equipment overloads, machinery jamming, reversing operations or sudden speed changes by increasing slip. During prolong startups, the fluid coupling allows the motor to accelerate to full speed before the load resulting in lower current draw and preventing overheating. Fluid couplings are used in many applications including conveying systems, crane travel drives, processing equipment, and line systems such as filling and packaging.