The core of the overload couplings (safety couplings) is formed by the idle rotation elements. They uncouple the driving and driven side in case of overload while protecting the drive train from damages. After eliminating the overload, the rotation segments are manually re-engaged so that the drive is released again. In order to set the coupling to the requested release torque, a defined pre-stress is generated on the disk springs in each idle rotation element via setting the nut. The number of idle rotation elements within the overload coupling varies depending on the release torque specified. If requested, the overload coupling can be preset by the manufacturer. It is also possible to adapt the safety coupling while in place.
Applications of our idle rotation overload couplings KTR-SI FRE:
- steel mills
- tunnel drilling machine
- test benches
- shredders (recycling)
Information on selection of torque limiters:
For an accurate selection of the safety coupling latest simulation and calculation programs are available. So please advise as many details of your drive as possible. The more accurate the data, the more accurate are the calculation results. Make use of these options and consult with us about the application beforehand.
To make sure the safety coupling is not released with process-related torque peaks already, the shifting torque of the safety coupling should exceed the maximum operating torque by at least 30 % (see diagramme).
Safety couplings and overload systems that re-engage automatically should be used with reduced speed with high release torques only. Frequent or longer slipping or engaging increases wear of the torque limiter.
After the safety coupling has separated driving and driven side in case of overload, it may take some time before the drive stops due to large mass inertias in the drive train. This may generate early wear of safety couplings and overload couplings that re-engage automatically. That is why we recommend with drives with large mass inertias or higher speeds to use the safety coupling KTR-SI as an idle rotation version.
We basically recommend electrical monitoring of the safety coupling to disengage the drive immediately in case of overload. We will be pleased to assist you with any technical questions about the selection of safety couplings.
Setting the release torque of the overload coupling:
In order to set the coupling to the requested release torque, a defined pre-stress is generated on the disk springs in each idle rotation element via the setting nut. The number of idle rotation elements varies depending on the release torque specified. If requested, the coupling can be preset by the manufacturer. It is also possible to adapt the coupling individually while in place.
Re-engagement of the idle rotation elements of the safety coupling:
After elimination of the overload driving and driven side are aligned to each other. By means of a plastic hammer or a tyre lever the idle rotation elements are manually re-engaged. Re-engagement can be heard loudly. The overload coupling is ready for use again.
ROTEX®, GEARex® or RADEX®-N