US Patent 9657716 Rotational support of a wind turbine blade

The invention resides in an assembly for rotationally supporting a wind turbine blade (110) relative to a wind turbine hub (120). The assembly comprises an intermediate ring (130) having an inner annular portion and an outer annular portion provided with means for attaching the turbine blade. The intermediate ring is rotatably mounted to the hub via a first bearing arrangement. According to the invention, the first bearing arrangement comprises a radial bearing (140) and a thrust bearing, whereby the inner annular portion is mounted to the hub via the radial bearing and the outer annular portion is mounted to the hub via the thrust bearing. The thrust bearing is a plain bearing comprising first and second sliding surfaces (151, 152) which are clamped to the hub between first and second clamping members (161, 162).