New compact ring drive has a built-in brake
Nexen Group
The new compact ring drive (CRD) system, CRD 250B (photo), includes a built-in zero-backlash locking brake design that delivers twice the nominal torque without increasing the CRD footprint. It is durable, with a brake life of one million cycles, and requires little maintenance. The brake is spring engaged and pneumatically released so that it will default to lock in a power-failure or emergency situation. The CRD has a precision-grade bearing and drive mechanism in sealed housing. The three-drive design configurations allow it to be optimized for high speeds of up to 225 rpm, high torque or both. — Nexen Group, Inc., Vadnais Heights, Minn.