Air-Engaged Torque Limiters Offer Superior Overload Protection

Unique design and features deliver key advantages over competitor products

Nexen Group’s pneumatically-engaged, single or multiple-position Torque Limiters deliver industry-leading overload protection for drives and driven products. Backlash-free torque transmission is accomplished by a series of balls nested in hardened detents in the unit’s interface. When an overload occurs the actuation ring moves axially, allowing the balls to come out of the detents separating the drive and driven elements. The movement of the actuation ring is sensed with a proximity sensor triggering the drive to shut down.

Key advantages of Nexen’s Air Engaged Torque Limiters include a hard chrome detent interface, which decreases drive ring wear when the balls are pressed against the face during the jog-to-engagement step, and an air chamber sealed with O-rings and back-up rings, which extends the life of the Torque Limiter by preventing O-ring extrusion during long engagement periods. Additionally, internal springs separate the interfaces at disengagement, preventing the ball from being forced out of the detent in an overload condition. This feature extends Torque Limiter life, prevents detent distortion and stops the Torque Limiter from trying to re-engage until the machine is stopped.

Nexen Air Engaged Torque Limiters also offer a remote torque setting with an air regulator, an advantage over mechanical torque limiters which require “hands-on” torque adjustment that can be inconvenient for the machine operator. A proximity sensor detects the overload condition and signals the directional control valve to exhaust the air and/or signal the drive to interrupt power to the prime mover.

Nexen offers more than 200 Air Engaged Torque Limiters with features including:

• Full and half-torque models

• Disengagement response time of 1-3 msec

• Torque ranges up to 28,000 in-lbs. at 80 psi

• Operating speeds up to 2000 rpm

• Bore sizes up to 2.438 inches

• Special units available for high temperature operation (up to 5000 F)

• Water protection per NEMA standard 1.26.5 (waterproof machine) or IP54

• Single or double-flex couplings to match the drive flange pilot surface and bolt circles

• Smart valve controller for multiple air pressure settings to one or more torque limiters

Nexen Air Engaged Torque Limiters are ideal for: packaging machinery (conveyors, feed screws, line shafts), continuous assembly lines, machine tools, CNC machine centers, woodworking machines, automation equipment, textile machinery, industrial robots, printing and converting, and sheet metal processing as well as servo and DC motor drives