Half of this device is used underwater and so must use corrosion-resistant parts. Ball bearings are not suitable, particularly underwater, as they need lubrication. Stainless steel bearings involve high costs. igubal® plastic self-aligning bearings are used, because they are corrosion and water resistant, lubrication-free and low cost.
An igubal® clevis joint is used in a linear application in the upper drive enclosure (pictured, left).