Windage Loss in Larger High-Speed Gears

Some preliminary measurements have been made of the windage loss in a number of larger spur gears and one helical gear, in air, and of how this windage loss is affected by speed, size, details of the gear geometry and the shape of enclosures. It is shown that for most gears the larger part of the windage loss arises from the teeth. Some comments are made on the mechanisms of windage loss and an empirical formula is given to estimate roughly the windage loss to be expected from a gear. The experiments, however, were carried out in air and there is a lack of knowledge on the effects of oil vapour, mist and larger drops in the atmosphere on the windage loss.