Bearingless Encoder

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 opto-electric transceiver located on the stator. Optical encoder technology relies on 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.

The Alternative – Bearingless Encoders

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:-

  • Lower start-up turning torques
  • No service or maintenance requirements
  • Greater reliability due to reduction in parts count
  • Eradication of seals and baffles
  • Direct coupling of rotor and stator to host equipment
  • No heat generation from friction at high speeds.
bearingless encoder

Fig.1. Zettlex IncOder inductive angle encoders can be considered as ‘bearingless encoders’ –  the rotor is completely free to move relative to the stator