Abstract: A planetary type gear transmission unit suitable for a wind turbine comprises sun (27), planet (25) and ring (24) gears and a planet carrier (41), the planet carrier comprising a planet bogie plate (43) which supports and locates circumferentially spaced planet gear bearings (45,46) on which the planet gears are mounted, and at least some of said bearings (45,46) being taper roller bearings.

Abstract: A wind turbine gear unit has a low speed gear module and a plurality of high speed gear modules wherein the low speed gear module is operable simultaneously to transmit torque to each of the high speed gear modules.

Abstract: In a gear unit for use in wind turbines and of the kind with a planetary gear stage, and an integrated main rotor bearing that is adapted to provide location for the rotor hub relative to the wind turbine nacelle and to locate the planet carrier relative to a low speed ring gear, the forces due to bending moments acting between the rotor hub and nacelle are transmitted substantially directly from the rotor hub to the nacelle via the main bearing and substantially none of the bending moments are transmitted to the nacelle via the ring gear of the planetary gear stage.

Abstract: A gear unit comprising a planet gear rotatable about a sun gear and supported by a planet carrier, said planet carrier comprising an annular formation for flow of lubricant and which is substantially concentric with the major axis about which the planet carrier is rotatable, and the gear unit comprising a housing having at least one lubricant supply position provided at a position radially aligned with said annular formation of the planet carrier as considered relative to said major axis about which the planet carrier rotates, and the planet carrier comprising flow paths for flow of lubricant from said annular formation to a planet gear bearing. The invention also discloses a method of lubricating a gear unit.

Abstract: A gear unit for use in wind turbine applications has a dry sump and is lubricated from an external reservoir whereby routine oil change may be undertaken by removing an external reservoir containing used oil and replacing it by a reservoir containing fresh oil.

Abstract: A drive assembly for a wind turbine (10) comprises a rotor hub (14), supporting structure such as a turbine nacelle (15), a planetary type gear transmission unit comprising sun, planet (47, 48) and ring gears (49) and a planet carrier (41), said planet carrier comprising a planet bogie plate (43) which supports and locates circumferentially spaced gear bearings (45, 46), said bearings (45, 46) being able, in use, to self adjust in angular position relative to the plate (43) whereby the rotational axes of the bearings (45, 46) may be either perpendicular to the general plane of the bogie plate (43) or depart therefrom.