• What was needed: iglidur plain bearings
• Requirements: the ring motor and bearing points are permanently underwater. The bearings must therefore function permanently despite the high salt content and possible contamination. In addition, bearings had to be as light as possible since any additional weight would mean increasing the size of the drive.
• Industry: shipping
• Success for the customer: the polymer bearings proved to be the best solution for the application. In contrast to metallic solutions, they are corrosion-free and lightweight. Compared to ceramic bearings, they have a higher load limit and are extremely wear-resistant.

Ring motors (torque motors) have no mechanical connection between the rotor and stator during operation. The magnetic ring (rotor) is only centred by the magnetic field of the stator and held in the magnetic field. A bearing for the magnetic ring is therefore only necessary during the start-up phase of the motor.
However, the demands on the bearing point are exceptionally high due to the special environmental and operational situation. This means that the ring motor and bearing points are permanently underwater and exposed to high salinity, corrosion and possible contamination. It was also important to find bearings that were as lightweight as possible as any additional weight in the water had to be bought at a high price by increasing the size of the drive.

The designers finally decided in favour of iglidur bearings in the ring motors, which were able to solve the problems permanently. The polymer bearings are suitable for use in and on underwater vehicles and boats due to their corrosion resistance, low moisture absorption and low weight compared to metallic solutions. Compared to ceramic equivalents, the iglidur bearings also offer the advantage that they have a high load limit and are extremely wear-resistant. While initial tests with impacts caused problems with the ceramic bearings, the special bearings made from high-performance polymers remained dimensionally stable, even in the long term, which is another important aspect for dynamic fields of application.