These systems are used in electronics production to supply workpiece carriers or masks to various placement, manufacturing and testing processes. In a combined rotation and conversion step, the product being conveyed – for example, a solder frame – is first of all separated ahead of the converter module, then pulled in by the drive unit in the rotary station, positioned, turned through 90° with a rotary motion and finally discharged again. Rotary converters that work on two levels – one for feeding and one for return – are particularly efficient here.

The aim when developing the new rotary converter was to optimize the actual rotary motion – and hence the performance of the module as a whole. Two possible ways to boost efficiency were identified by haprotec’s engineers: to add dynamics to the rotary motion according to the workpiece and to increase the rapid speeds when the rotary unit is reset. The desired effect here was to achieve significantly shorter cycle times – and correspondingly higher throughput. The new drive solution had to fit into the enclosure such that the workpiece carriers could be returned on the bottom level. The close cooperation between haprotec as the manufacturer of the machine, Siemens as the motor and controller supplier and WITTENSTEIN alpha as the specialist for transmission technology resulted in a drive unit that meets all of the above requirements – and in some cases exceeds them.

This combination enables dynamic and accurate positioning of the new rotary converter as well as precise motion control. WITTENSTEIN alpha’s V-Drive Basic worm gearbox provides all of these performance features in the shaft version. The redesigned involute toothing of the worm is key here. The positioning accuracy of less than 15 arcmin which is specified for the V-Drive Basic and required by the application is permanently achieved by the dynamic rotary converter. Even different rotational speeds have no noticeable impact on the precision of the rotary motion. The V-Drive Basic additionally impresses with high torque reserves, so that the full power potential of the servo motor is unlocked.

The ability to adapt the conversion rate dynamically has made an important contribution here. Maximum permissible values for the acceleration and speed of the rotary motion are stored for each workpiece carrier. By accessing this information, the rotary unit can move many different workpiece carriers in a very short time. The fact that the converter executes empty runs at maximum speed enables even shorter cycle times and optimal throughput. Finally, the high dynamic reserves of the motor-gearbox unit transform haprotec’s new rotary converter into a highly sustainable handling module for the company’s end customers – especially since the drive can also be adapted very easily to changes in the external conditions or the torsion angle.