Kaco has introduced shaft grounding rings developed specifically for electric vehicle propulsion systems. This solution ensures a permanent electrical connection between rotor shaft and grounded housing, and therefore prevents metal bearings from harmful currents.
As well as protecting the metal bearings from damage, the grounding rings prevent mid-frequency noise interference. This is thanks to a highly conductive PTFE disc with special coating.
Kaco’s latest sealing technology has been designed to work under circumferential speeds of up to 45m/s within a temperature range of -40°C to 140 °C. Further optimizations and alternative solutions for higher circumferential speeds are already at testing stage.
Within a dry running system, the electrical impedance will reach around 5Ω between rotor shaft and housing. Kaco’s grounding rings – which are fully independent from the shaft’s direction of rotation – offer protection for bearings and gear wheels, as well as significant reduction in impedance over the vehicle’s life.
