Philips Applied Technologies recently developed a technique allowing standard linear motors to simultaneously provide movement along two axes rather than a single axis. This technique, patented as NForcer Technology, will allow designers to reduce the number of motors and electronic drive modules typically required for industrial automation machines.
According to the company’s press release, manufacturers of pick-and-place and wafer processing equipment can produce more accurate production stages using this technology. The dual-axis linear motor provides a cost-effective solution for pick-and-place applications and comes with all the benefits of linear motors.
“The beauty of this new innovation in linear motor operation is that it requires absolutely no modification to existing motor components,” says Dr. George Angelis, senior scientist at Philips Applied Technologies. “All you need to do is re-position the components slightly and drive them in an intelligent way.”
The technique allows horizontally mounted linear motors to generate lift as well as lateral motion, providing both axes of motion from just one motor. It also enables the production of precision, magnetically levitated platforms with six axes of controlled motion.
In a conventional linear motor, the current carrying conductors are arranged in coils with only the vertical sides in the magnetic field, resulting in lateral motion. To achieve two-dimensional motion from a single motor, researchers at Philips Applied Technologies have shifted the position of the coils so the lower horizontal section also sits in the magnetic field.
According to the company’s press release, NForcer Technology allows the production of fully floating bearing-less platforms that can be used in a vacuum, unlike air-bearing solutions. This platform can be implemented with only four horizontal magnet tracks and six forcers.
Philips first tested NForcer Technology by electromagnetic and mechanical dynamic modeling in a simulation environment. To confirm simulations, engineers also tested a commercially available motor by measuring the forces and torques generated with NForcer. The engineers began designing a few prototype systems with their results.
Philips recently demonstrated this technology at the American Society for Precision Engineering Annual Meeting in Dallas, Texas. Demonstrations included a single-track roller bearing pick-and-place mechanism with 20 cm horizontal and 3 cm vertical movements achieved with a single forcer and a magnetically levitated platform movable in six degrees of freedom with nanometer accuracy. Both were constructed from standard “off-the-shelf” motor components.
“The reaction from the linear motor companies was ‘Why didn’t we think of that?’ says Joost Maltha, communications manager at Philips. “Engineers were dumbfounded and surprised by the simplicity of the invention.”
The development of this technology stems from Philips’ work in providing industry with mechatronic solutions ranging from servomechanisms to positioning platforms for silicon chip manufacturing. The company will license NForcer to linear motor manufacturers/suppliers so they can immediately utilize the technology.