UMC International designed polymer plain bearings into a new boat hull cleaning machine for use by underwater divers. The bearings require no lubrication and are impervious to corrosion and salt water.
The Hampshire-based company manufacture hydraulically powered hull cleaning machines, which typically have two rotating brushes. The vehicles can be powered forward or reversed, steered and the brushes raised and lowered on a gimbal mechanism. The usual cleaning speed is 1,000 square metres per hour.
The original pamper vehicle weighed 250kg, and a re-design was required to give a more compact and lighter vehicle. The steering assembly, for example, weighed too much due to the use of ball and roller bearings inside a watertight housing. These bearings also required a high maintenance regime.
iglidur H polymer bearings from igus were selected for the new design to support various parts of the brush lift and articulation device. These plain bearings are self-lubricating and so require no maintenance.
iglidur H is a fibre-reinforced thermoplastic material developed especially for applications in high humidity or underwater. Plain bearings made from iglidur H can be used completely lubrication-free. In wet areas, the surrounding medium functions as an additional lubricant.
The steering mechanism is a handlebar at the front, connected to a propelled castor at the rear. Each is supported by large bore iglidur Z plastic bearings, which provide a substantial weight reduction, zero maintenance and no corrosion whatsoever in salt water.
iglidur Z is a high temperature bearing material, which is suited for applications with very high specific loads. iglidur Z is suited for both average and high speeds due to its high thermal resistance.