Overload Safety Devices
Zero-Max’s Torq-Tender overload safety devices incorporate torque limiters for dependable overload protection. When a jam-up or excessive loading occurs, the built-in torque limiter will reliably and quickly release to prevent system damage.
The Torq-Tender torque limiter is tamper-proof. Once installed, the torque value cannot be changed. This feature ensures the integrity of the machined design, and renders costly and potentially risky calibration procedures unnecessary. Torque value is controlled by the part number that is ordered; that value determines what spring is used during assembly of the torque limiter.
- Torque values can be changed in the field, however; the torque limiter must be disassembled and the springs replaced to achieve the new torque value.
- Standard Torq-Tenders are bidirectional. Torque value remains the same regardless of rotation. If specified, the torque limiter can be configured at the factory to release at different torque ratings for different rotational directions.
- When used as a coupling, the Torq-Tender fulfills two functions: 1) A flexible shaft coupling; 2) a mechanical torque limiter.
- In the shaft-to-shaft configuration, the Torq-Tender can accommodate angular shaft misalignment up to 1.5° and parallel misalignments from 0.005” to 0.015”.
- The enclosed design of the mechanical torque limiter enables it to operate in a wide variety of industrial environments. Special designs and materials can be used to withstand even the most adverse conditions.
- Every Zero-Max torque limiter is made from durable heat treated steel for a long operational life.
How Torque Value is Determined
The torque value of a Zero-Max Torq-Tender is determined by the force of the springs that are installed in the unit. The spring force acts upon slides that are part of the inner shaft; these slides transmit force that holds the drive key in its engagement slot in the outer housing.
When the torque load exceeds the rating of its precision tempered torque springs, the Torq-Tender’s drive key pivots out of the engagement slot to disengage the device. When disengaged, the torque limiter does not provide significant resistance to rotation.
Upon the completion of one shaft rotation, the torque limiter will automatically attempt to reengage. Once the overload is removed and speed is reduced, the drive key will snap back into the engagement slot and the Torq-Tender will be reset for the next incidence of overload.