Preventing Damage and Production Downtimes
Torque limiting clutch protects the feed drive on a multiple die press
In order to guarantee maximum operating safety, a mayr Antriebstechnik EAS-Compact torque limiting clutch has been integrated into the feed drive of a multiple die press. It limits the torque and protects the drive against overload damage. Direct safeguarding of the linear feed movements via force- l imi t ing elements proved impossible due to lack of space.
- A feed drive with a pendulum action gear: In order to protect from overload damage, an EAS -Compact torque limiting clutch mounted on the output shaft limits the torque accurately to the set value.
In a multiple die press, workpieces are moulded into the required shape step by step in a pulsing procedure. A feed drive especially designed for this press transports the workpieces onward. The pendulum action gear integrated into the feed drive carries out 50 double strokes per minute. In order to protect the drive unit from overload damage during collisions or operational malfunctions, the press operator initially planned to safeguard the linear feed movements with two parallel-positioned EAS -axial overload elements. These elements limit forces in tensile and pressure direction to the set value and can generally be integrated very close to the potential collision point. However, it proved impossible to integrate these force-limiting protective elements on this application without an excessive amount of effort due to lack of space. Instead of this, an EAS -Compact synchronous clutch was positioned at the output shaft of the lifting gear in order to overcome the limits set by the installation restrictions. In this way, the feed drive could be safeguarded reliably against overload damage and high operational safety was ensured for the system.
In order for a torque limiting clutch to offer optimum protection, it must feature several basic qualities. One of the most important of these is the backlash-free function. Particularly in dynamic and reversing drives, torsional backlash leads to wear, and possibly even to clutch failure as a result of this wear. mayr torque limiting clutches in the EAS-NC, EAS-Compact and EAS -smartic series work completely backlash-free over their entire lifetime and are therefore suitable for demanding and highly-dynamic drive concepts. The basis for their reliability is the ingeniously simple function unit for torque transmission and limitation. A ring, pretensioned via cup springs, presses balls simultaneously into recesses in the driven clutch hub and into recesses on the output-side component. Even if the recesses wear down, this system remains backlash-free, because the balls are simply forced deeper into the recesses, thereby compensating for the wear. Several systems produced by other manufacturers lose their backlash-free capabilities after longer periods of use. Apart from that, there are a large number of providers still working with transmission systems which are subject to backlash.