published on 18/07/08
The art of shifting stuff about has posed a perennial challenge for manufacturing. From the precision placing of electrical components to the moving of large items such as whole ships, the methodologies have revolved around guiding systems such as rails, and some means of moving the product along the system, such as belts and ball bearings.
Many everyday items have to be moved about at some point. Even the signs at McDonald's rely on bearings to change menus.
Printing environments are often dusty, dirty places and, as a result, the lubricants in moving parts such as bearings are prone to seizing up and contamination. Cleanliness can also be a problem for lubricated bearings. Germany-based Belimed Technik specialises in cleaning, disinfecting and sterilising equipment and services for the pharmaceutical industry, healthcare establishments and laboratories. It used SKF purpose-designed polymer ball bearings for its new PH 8xx.2 type range of cleaning machines, as they offer low friction and the ability to operate under high temperatures.
Even the humble bearing has been subject to some interesting twists in an attempt to reduce bearing friction to zero, which not only makes maintenance easy as there is limited wear, but also enables more precise positioning.
Netherlands-base IBS Precision Engineering recently announced the launch of its new range of porous air bearings that it claims combines virtually frictionless motion with high load-carrying capabilities and positional accuracy.
The Barden Corporation (part of the Schaeffler Group), makes what it calls active magnetic bearings, which provide a method of suspending shafts (both axially and radially) in applications, such as turbomolecular vacuum pumps (used in semiconductor manufacturing), dry pump bearings, compressors, blowers, air conditioning systems, gas expanders (used as venting devices in gas pipelines) and in energy storage systems as emergency back up power.
The bearings use actively controlled electromagnetic forces to control the motion of a rotor or other ferromagnetic body in air.The advantages of this non-contact style are similar to those of air bearings — reliability, low maintenance and the lack of the need for lubrication.
So when it comes to moving and positioning anything from components to larger items, the technological advances in what are essentially simple components such as bearings with air, and magnetic bearings are at the cutting edge.
Read the full article at The Engineer