ROTARY CAPACITOR FOR SHUNTING HIGH FREQUENCY BEARING CURRENTS AND REDUCING EMI IN ELECTRIC MACHINERY

摘要

Rotary capacitor assemblies divert or mitigate high-frequency electrical currents and voltages in bearings of electric machinery (e.g., motors and generators) without direct contact with the bearings. The assemblies include rotating capacitors, in which surfaces in close proximity are free to rotate with respect to another while maintaining relative surface area and separation distance. A lubricant (such as air or oil) facilitates capacitive surfaces hydrodynamically "floating" on each other. The assemblies may take different forms, such as concentric hoops / sleeves, parallel disks on a common axis, an axial thrust body, or a cylindrical member inserted into the shaft. The shunt body is connected electrically in parallel with the bearings of the machine, providing a non-contact or nearly non-contact electrical pathway for damaging high-frequency currents and voltages to be shunted around the mechanical load carrying bearings, increasing their life span and reducing electromagnetic interference without adding to bearing wear and tear.