Bearingless encoders are typically used to measure angular displacement in rotary motion applications. Most encoders use optical techniques, where the rotor is an optical disk which co-operates with an optoelectric transceiver located on the stator. Optical encoder technology relies on the accurate and tightly controlled rotation of a rotor relative to a stator. Bearings are typically used to keep rotor and stator concentric. The introduction of mechanical moving parts has a number of disadvantages, especially in harsh operating environments.
Zettlex IncOder inductive angle encoders can be considered as ‘bearingless encoders’. In these devices, the rotor is completely free to move relative to the stator – if bearings are involved they are typically already present in the host system. The eradication of bearings from the encoder results in:-