Calnetix gets patent for mag bearing position sensor

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Calnetix Technologies recently received a new patent for its magnetic bearing “constant-flux” edge position sensor invented by Principal Research Engineer Alexei Filatov.

 This is the seventh U.S. Patent issued to Filatov since he joined Calnetix in September of 2002.

 “Position sensors are critical components of any Active Magnetic Bearing (AMB). Their role is to continuously provide the magnetic bearing controller with accurate, up-to-date information about the rotor position unaffected by external factors, such as speed, temperature, dust, working fluids, external magnetic, and electrical fields,” said Filatov.  “While the radial inductive position sensors were easily meeting AMBs requirements, a textbook axial inductive position sensor had significant limitations. Our ‘constant-flux’ edge sensor overcomes drawbacks of the previously available axial position sensing technologies and provides a unique combination of advantageous properties.”


 Since 2011, the constant-flux edge sensor has been the standard axial position sensor solution in Calnetix’s magnetic bearings and has been successfully implemented in many commercial machines in a wide variety of applications. The benefits of Filatov’s invention for AMBs include, but are not limited to:

·         Ability to work in dusty environments and in many working fluids.

·         Low sensitivity to EMI and external DC magnetic fields.

·         Large measurement range in excess of 0.2 inches (5 millimeters).

·         Excellent linearity over displacement ranges typical for AMB applications.

·         Excellent temperature stability.

·         Large temperature operating range (tested up to 175 degrees C and up to 250 degrees C theoretically possible).

·         Pass-through assembly.