Abstract: A wind turbine gear box arrangement having one or more bearings located in a single region along the longitudinal axis and arranged to provide support between an input shaft and a non-rotating support component. The one or more bearings are arranged to at least partially restrict non-rotational movement between the input shaft and the non-rotating support component. A portion along the longitudinal axis between said input shaft and the non-rotating support component is bearingless outside the single region.

Abstract: A gear arrangement including a first gear arranged to rotate about a first longitudinal axis and including a first plurality of gear teeth, and a first portion including a first surface and a second gear arranged to rotate about a second longitudinal axis and including a second plurality of gear teeth, and a second portion including a second surface. The first surface and the second surface are arranged to abut one another and restrict relative non-rotational movement of the first gear and the second gear.