Cerritos, Calif. – October 21, 2013 – Alexei Filatov and Lawrence Hawkins, Principal Research Engineer and Director of Technology for Calnetix Technologies, a pioneer in high-speed permanent magnet motor generators, power electronics and magnetic bearings for a variety of applications and industries, will present at the 1st Brazilian Workshop on Magnetic Bearings in Rio de Janeiro later this week.
They will speak on a novel combination radial/axial homopolar active magnetic bearing system they developed.
“The design combines the best features of the earlier solutions – shorter axial length, lower part count, lower aerodynamic drag, lower negative stiffness and lower cost typical for combination bearings – along with a better axial bandwidth typically demonstrated in arrangements of separate radial and axial bearings,” said Filatov. “Furthermore, the actuator topology leads to a rotor tapering towards the ends, which is a preferred geometry from the rotordynamic point of view in most turbomachinery applications.”
The actuator consists of a radial portion and an axial portion with two radial control axes adjacent to an axial control axis; however, the same permanent magnet generates both the radial and axial bias flux. A similar design has been previously described in the literature, but it was impractical to use because of a strong modulation of the bias flux by the axial control current. Calnetix has resolved this issue in the new design by introducing a flux compensation coil between the axial and radial actuator portions.
“Both theory and experiment show that without the compensation coil, the radial bias flux for example may change by as much as plus or minus 35 percent of the nominal value when axial control current is changed,” said Hawkins. “With the compensation coil, the radial bias flux changes less than plus or minus two percent throughout the axial control current range.”
The goal of the 1st Brazilian Workshop on Magnetic Bearings is to internationalize the Brazilian activities in this field as well as prepare to receive an International Symposium on Magnetic Bearings in the near future. The conference is being organized as a satellite activity of the traditional Brazilian Congress on Power Electronics and receives support from the Brazilian Society on Power Electronics as well as the Brazilian Society on Automatic Control. More information is available at www.magneticbearings2013.com.br.
About Calnetix Technologies
Calnetix Technologies, LLC (“Calnetix”), headquartered in Cerritos, CA, is focused on Innovation That Drives Industries. The company specializes in high-performance, high-speed motor generators and best-in-class advanced magnetic bearings and control systems. Calnetix’s patented, underlying technologies, which have been in use since the company’s inception in 1998, have made Calnetix a world leader in the design and production of high-speed machines. The company’s overall technology portfolio and system integration capabilities have led to development and production contracts with industry leaders and the start of many successful subsidiaries that focus on unique niche markets. For more information, please visit www.calnetix.com.