Design Improvement of Fiber Optic Rotary Joint

Taking advantages of large transferring capacity, wide bandwidth, excellent electromagnetic compatibility, small size, light weight, low energy consumption and small noise, fiber optic rotary joint (FORJ) has been widely used in radar facilities. However, multiple FORJs suffered from increased insertion loss or connection failure in actual use. In order to tackle this issue, rating life of the supporting bearing was evaluated, the reason of premature failure was further analyzed. Several design improvements for FORJ were proposed, including appropriate bearing model specification, lengthened bearing center distance, and narrowed distance to rotor pressure point. These measures could improve the stress condition of bearing, resulting in longer expected life of bearing and better reliability of FORJs.