The ST2 series torque limiter from R+W allows for one compact unit to be installed, saving space and cost when into a high horsepower driveline that normally requires modifying or purchasing a customized flexible coupling or fabricating a shaft adapter to allow for standard coupling use. Mechanical torque limiters are often implemented after the original equipment has been designed or installed, making space a premium.
The ST2 uses a vibration damping jaw type coupling in conjunction with a resettable torque limit function. After reaching a preset disengagement value between 738 and 118,000 ft-lbs, the coupling fully disengages and freely rotates over a high strength internal bearing until the machine shuts down. This helps to avoid any overload damage to gearboxes, shafts or other parts.
Resetting the coupling involves snapping the individual plungers back into engagement with a pry bar or mallet. These safety couplings have four body sizes and anywhere from three to nine plungers, depending on torque setting. The adjustable plungers can be added or removed after installation in case of miscalculation of the torque value release. The ST is also available as a pure torque limiter or with integral gear coupling or disc coupling.