A comprehensive range of torque limiters has been brought together by Techdrives, a division of Lenze Ltd. Torque limiters, also known as safety couplings, protect products, machine parts and tooling from damage resulting from jams and mishaps. They disconnect the driving parts from the load but cannot remove inertial energy; therefore they are most effective when used at low speeds. The Techdrives range covers six basic types with more than 20 design variants and a torque range from 1-30,000Nm.
The most commonly used models are friction, ball and roller designs. Friction torque limiters are often combined with chain sprockets. They are low-cost, simple to adjust and available in a wide range for shafts from 5-140mm. However, they should not be used for frequent overloads except at low speeds, and they require a moderately clean environment.
Ball and roller torque limiters can be considered together. They can run at higher speeds, are more accurate in the release torque, are maintenance-free and suitable for oily environments. Overloads create axial movement that can readily be detected by a proximity switch and used to stop the drive. Techdrives offers a low-cost ball design plus a wide range of other models suiting different loads and mounting configurations. These torque limiters can be used to synchronise, detect overload without releasing, or give a fast and free release.
Also available are designs with pneumatic operation, which allows for adjustable release torques - for example, at a high level for acceleration and a lower more sensitive level for running conditions. Backlash-free torque limiters for overload torques up to 750Nm suit precision machinery that needs accurate positioning.
In addition, Techdrives offers a range of linear slide limiters that work in tension or compression, accepting high axial loads and triggering release at an adjustable point. These can be used in reciprocating mechanisms and torque arms.
Techdrives brings together all the information that a machine designer needs for torque limiters. There is advice on selection and mounting, together with a download of a 28-page catalogue with clear product information.