DAC102021

36 n MACHINE BUILDING October 2021 www.drivesncontrols.com Actuator upgrade ends failures on automated screwdriving machine A VK Plastics, a Dutch manufacturer of synthetic surface boxes and pallets, was having problems with an actuator which was a key component in an automatic screwdriving application. The actuator moves a screwdriver horizontally to fix three screws into a pallet at 300mm intervals. Precision and repeatability are key requirements because the screwdriver needs to be precisely aligned to fasten the screws into the screw holes. It also needs to be stable to achieve the required precision and accuracy. But, according to Hylke Vlieg, AVK’s technical services manager, the actuator that the company was using previously could not provide the high stability required. “There was play on the car in no time, which did not improve accuracy,” he reports, and after 14 months of operation, the actuator broke. AVK decided to replace the failed component with a belt-driven actuator from HepcoMotion. Based on a ball-rail technology, the new actuator’s carriages are pre-loaded to eliminate play and to deliver high rigidity for precision applications such as this. As AVK had found with its previous system, any movement in the carriage plate can affect the accuracy of the screwdriver. The resistance to movement provided by the belt-driven actuator was therefore of utmost importance. The automatic screwdriver and accompanying equipment provide an 18kg payload, which the SBD belt-driven actuator can handle. The zero-backlash system ensures good positional accuracy and repeatability, which was essential for the screwdriving application, which required an accuracy of 0.1mm. The upgraded system can fasten the three screws into a pallet in 15s. The high-duty application is now operating around the clock, seven days a week. Hepco has promised AVK a service life of five years, and claims that the actuator will provide a higher level of performance in terms of load capacity and life, than similar- sized devices. The machine’s frame is constructed using Hepco’s MCS aluminium profiles, and the actuator is powered by a servomotor and energy chain. The upgraded system has been operating trouble-free for more than 10 months, with the only maintenance required being to spray grease periodically into the re-circulation block. “I am very satisfied with the stability and accuracy of this system,”Vlieg reports. “It also needs little maintenance.” n A Dutch manufacturer which suffered a failure of a key component in an automated screwdriving application, found that upgrading to a new belt-driven actuator gave it the accuracy, stability and long operating life it required. AVK’s upgraded automatic screwdriving system can fastens three screws into a pallet in just 15 seconds.