July 15th, 2020
Using a Tolerance Ring can be a simple way to introduce a mechanical torque overload protection into a complex system. The torque limiter will increase life-time and reduce space and weight of the final product.
Robot toys often fall off a table-top, distracted people can stumble over robot vacuums, and electrified hinges on toilets seats or cars get abruptly stopped.Damage caused by such misuses or input shocks can be avoided by using a torque limiting device. Such devices can be required for servos, stepper motors, or in gears driving the systems.But most of these systems are complex, bulky and expansive. A RENCOL® Tolerance Ring uses one component in line with the mating existing components, and it reduces space, weight and additional costs. The RENCOL® Tolerance Ring solution is custom designed to torque levels of 0.2 Nm to 300 Nm and beyond.
The Rencol ring is introduced between the drive gear and the output shaft, so if, for example, the output drives against an obstruction, or receives a shock load, the Rencol ring will permit momentary slip between the gear and the shaft.The output shaft position is monitored by the servo angle sensor or potentiometer, so when slip occurs, the system ‘knows’ what happened and can deal with it whilst not losing positional registration.The ring can be engineered so slip occurs at a torque level suited to the rating of the servo, or to that of the driven system, depending on what should be protected.The graphs in the 2 charts below show 0.4Nm torque slip, but an even higher slip torque of 2.5Nm for this particular servo would be possible with a RENCOL® Tolerance Ring design.
Most of these systems are complex, bulky and expansive. A RENCOL® Tolerance Ring uses one component in line with the mating existing components. It reduces space and weight at low cost. Find further information on RENCOL® Tolerance Ring as Torque Limiter or Slip Clutches on our product page.