Hoerbiger-Origa has supplied its specialist clean room rodless cylinders for a pick-and-place system that transports computer hard drives.
Pneumatic actuation has not always been the first choice for high-precision clean room operations, being considered a high-risk source of contamination. But Hoerbiger-Origa has overcome this problem with its clean room series of cylinders, and has developed a system that provides a pick-and-place transfer operation in the manufacture of PC hard drives.
In the micro-electronic industry, the reliability and accuracy of conveyor systems are crucial, as is the ability to function within a Class 10 clean room environment. In the past, the focus has been to reduce the number of pneumatic cylinders introduced into clean rooms. But the levels of cleanliness and positioning accuracy offered by these new products is said to open up a whole new design option.
Comparison with stepper motors
In operation, the cylinder lifts a cradle of PC hard drives from a low-level conveyor and raises them 2m to a second conveyor. During this vertical transfer, the load is rotated through 90degrees before being lowered into position. The cylinder then automatically resets to collect the next cradle. The pneumatic system is clean and precise, and costs one-third of the equivalent stepper motor system.
A clean room standard rodless cylinder provides the required travel and is fitted with a positioning system and active brake. An integral incremental sensing system ensures a positioning accuracy of +/-1mm and is linked to the PLC. As a rigid and integral part of the transfer system, the actuator provides optimum load carrying and stroke length capacity.
Hoerbiger-Origa's specialist cylinders meet clean room requirements by incorporating an integral vacuum system that practically eliminates particle emissions from the actuator. Moreover, the cylinder can travel slower than other actuator types - at less than 25mm/s - and therefore creates less air turbulence, which might otherwise disturb existing contamination in the operating environment.