New air bearing technologies for roll-to-roll printing applications
By Dr Theresa Spaan-Burke, Innovation Director, IBS Precision Engineering
Rolling element bearings developed in the last century were a revolutionary improvement over the plain bearings that had been pushed to their limits in applications like electric motors and automobile wheels. Air bearings can likewise be seen to represent the next logical step in bearing design. These may be exploited by mechanical engineers to extend their design capabilities for precision manufacturing systems. Air bearings use a thin film of pressurized gas to provide a low friction, load-bearing interface between surfaces. As the two surfaces do not touch, the traditional bearing-related problems of friction, wear, particulates, and lubricant handling can be avoided. The use of air bearings in certain precision systems is well established due to the distinct advantages they offer in precision positioning, such as zero backlash and constant static/dynamic coefficients of friction, so no stick-slip. Thus, they have been exploited in applications such as ultra-precision lithography machines and CMMs (Co-ordinate Measuring Machines). Low friction also means less heat generation, so less thermal disturbance, and minimal power loss for high-speed applications, such as high-speed precision spindles. While any heat generation is, of course, not zero, relative surface speeds of the order of 30 m/s must be reached before significant heat can be measured. In recent years, IBS Precision Engineering has been championing the use of air bearings in the area of roll-to-roll where non-contact, almost zero friction, and no static build-up can also be of great benefit to production processes.
IBS Precision Engineering BV NL-5633 AD Eindhoven, www.ibspe.com