International innovation for torque limiting clutches

Integrated transmitter renders external limit switches superfluous

Up to now, torque limiting clutches have required an external limit switch with a
cable to transmit a signal to the control system on overload. The EAS -Sensor
developed by mayr power transmission, a torque limiting clutch with an integrated signal transmitter, sends the overload signal via radio. This revolutionary and absolutely reliable overload recording system has substantial advantages in comparison to standard signal transmission devices.

Using precise torque limitation, torque limiting clutches ensure that the loads on parts in machines and systems do not exceed the permitted values. A mechanical overload safeguard works by separating the input and output in order to uncouple part of the rotational energy of the drive line. In this way, the loads having an effect on the collision point can be greatly reduced. The highly precise, backlash-free ball ratchetting clutches from the market leader, mayr power transmission, have proved the most suitable solution for many application areas.

Such positive-locking torque limiting clutches have up to now generally required an externally mounted limit switch, which senses the clutch disengagement movement on overload and transmits this in the form of an electrical signal via a cable to the control system. This signal is generally used to switch off the drive. Among other things, this prevents unnecessarily long ratchetting on the clutch, reduces the wear on functional surfaces, ensures high functional safety and guarantees a long service lifetime. The stroke movement made when the clutch
disengages due to an unpermittedly high torque totals only a few millimetres. This short path must be sufficient in order to change the switching conditions of the mounted mechanical or contactless limit switch. External limit switches must therefore be conscientiously and precisely mounted and adjusted so that they can function reliably. However, in some situations, maximum care proves to be in vain if the torque limiting clutch changes position during operation, for example due to heat expansion. 

The new EAS -Sensor, a torque limiting clutch with an integrated signal transmitter, transmits the overload signal via radio. This has substantial advantages in comparison to standard, cableconnected signal transmission systems with external limit switches.

mayr power transmission, market leader for mechanical torque limiting clutches, has combined clutch and limit switch in a revolutionary new development so effectively that external influences can have no negative effect on functional safety. On the new EAS-Sensor, the limit switch is directly integrated into the clutch. It registers the clutch disengagement movement on overload and transmits a wireless signal via radio to a base station which is combined with the machine control system. This makes the need for external sensors or limit switches with cable leads and appropriate mounting parts superfluous. What isn't needed doesn't use up space, meaning that construction space problems are solved. The EAS -Sensor is adjusted at the site of manufacture ready for operation. Assembly and adjustment work is no longer required. The overload recording is absolutely reliable. Vibrations and axial clutch misalignments - for example should the shaft heat up and expand - have no influence on functional safety. Using the new EAS -Sensor, reliable overload protection is now even easier to install.

The transmitter on the new system is completely located, including its power supply, in the torque adjusting nut on the tried and tested EAS -Compact torque limiting clutch. The transmitter reports to the base station in regular, brief intervals via a status telegramme. This ensures that the radio transmission and the transmitter are functioning correctly. Should the base station receive no report over a defined time period, it emits a malfunction report. If the transmitter has no connection to the base station, because for example the machine is down and the control system is switched off, it goes into energy-saving mode. During this time, the transmitter continues to attempt to renew connection to the base station at larger intervals. The system is ready for operation again at the latest 60 seconds after the base system has been switched on.