Abstract: A drive assembly for a wind turbine includes a rotor hub, a supporting structure, a planetary gear transmission unit having sun, planet and ring gears and a planet carrier. The ring gear is non-rotatably secured to the supporting structure. A main bearing rotatably supports the rotor hub and planet carrier relative to the ring gear and supporting structure. The drive assembly further includes two substantially independent force transmission paths for transmission of forces reacting with forces exerted by the wind turbine rotor hub. A first of the force transmission paths acts from the rotor hub via the main bearing to the supporting structure primarily for transmission of overhang load forces and bending moment forces and a second of the force transmission paths acts from the rotor hub via the planet carrier primarily for transmission of rotational forces.

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

Abstract: A drive assembly for a wind turbine includes a rotor hub, a supporting structure, a planetary gear transmission unit having sun, planet and ring gears and a planet carrier. The ring gear is non-rotatably secured to the supporting structure. A main bearing rotatably supports the rotor hub and planet carrier relative to the ring gear and supporting structure. The drive assembly further includes two substantially independent force transmission paths for transmission of forces reacting with forces exerted by the wind turbine rotor hub. A first of the force transmission paths acts from the rotor hub via the main bearing to the supporting structure primarily for transmission of overhang load forces and bending moment forces and a second of the force transmission paths acts from the rotor hub via the planet carrier primarily for transmission of rotational forces.

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.

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: A drive assembly for a wind turbine includes a rotor hub, a supporting structure, a planetary gear transmission unit having sun, planet and ring gears and a planet carrier. The ring gear is non-rotatably secured to the supporting structure. A main bearing rotatably supports the rotor hub and planet carrier relative to the ring gear and supporting structure. The drive assembly further includes two substantially independent force transmission paths for transmission of forces reacting with forces exerted by the wind turbine rotor hub. A first of the force transmission paths acts from the rotor hub via the main bearing to the supporting structure primarily for transmission of overhang load forces and bending moment forces and a second of the force transmission paths acts from the rotor hub via the planet carrier primarily for transmission of rotational forces.

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 comprises a planetary stage having at least one bearing which locates a planet carrier rotatably relative to a ring gear, wherein a bearing ring A is subject to local deformation as the planet carrier rotates relative to the ring gear, and wherein a bearing ring B, which is rotatable synchronously with the planet carrier, is precompensated whereby, in comparison with a non-precompensated bearing ring B, radial squeezing of the rolling members of bearing or load concentrations or local unloading of the rolling members of the bearing is reduced.

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.

Abstract: A drive assembly for a wind turbine includes a rotor hub, supporting structure such as a turbine nacelle, a planetary type gear transmission unit comprising sun, planet and ring gears and a planet carrier, the ring gear being non-rotatably secured to the supporting structure, a main bearing which is a double taper bearing and rotatably supports the rotor hub relative to the ring gear and supporting structure, and the drive assembly comprising two substantially independent force transmission paths for transmission of forces reacting with forces exerted by the wind turbine rotor hub, a first of the force transmission paths acting from the rotor hub via the main bearing to the supporting structure primarily for transmission of overhang load forces and bending moment forces and a second of the force transmission paths acting from the rotor hub via the planet carrier primarily for transmission of rotational forces.

Abstract: A drive assembly for a wind turbine comprises a rotor hub (14), supporting structure such as a turbine nacelle (15), a planetary type gear transmission unit (11) comprising sun (27), planet (25) and ring (24) gears and a planet carrier (28), said ring gear being non-rotatably secured to said supporting structure (15), a main bearing (23) which rotatably supports the rotor hub (14) and planet carrier (28) relative to said ring gear and supporting structure, and said drive assembly comprising two substantially independent force transmission paths for transmission of forces reacting with forces exerted by the wind turbine rotor hub, a first of said force transmission paths acting from the rotor hub (14) via said main bearing (23) to the supporting structure (15) primarily for transmission of overhang load forces and bending moment forces and a second of said force transmission paths acting front the rotor hub (14) via said planet carrier (28) primarily for transmission of rotational forces.

Abstract: An air impellor comprises a sheet of plastically deformable material having a plurality of cuts which each extend radially outwards from a central position defined by the intersection between said sheet of material and an axis about which, in use, the impellor is intended to rotate, each cut extending to an outer boundary edge (17) of the sheet material from an inner end base region which lies at a position spaced radially outwards from said central position, each vane segment (11) thereby defined by the sheet material lying between each successive pair of cuts having a twisted profile in which the local angle of inclination of a circumferentially extending line on said vane segment as considered relative to a plane perpendicular to said axis of rotation increases with increasing radial distance of the circumferentially extending line from said axis of rotation.

Abstract: A gear unit comprises a planetary stage having at least one bearing which locates a planet carrier rotatably relative to a ring gear, wherein a bearing ring A is subject to local deformation as the planet carrier rotates relative to the ring gear, and wherein a bearing ring B, which is rotatable synchronously with the planet carrier, is precompensated whereby, in comparison with a non-precompensated bearing ring B, radial squeezing of the rolling members of bearing or load concentrations or local unloading of the rolling members of the bearing is reduced.

Abstract: In a series of gear units with increasing torque, each gear unit comprises two or more stages comprising standardized shaft center distances (c, e) and standardized gear wheels (12, 14) and for any stage of given center distance and gear ratio the same intermediate pinion shaft is used systematically in a non-stepped two stage housing and symmetrically stepped three stage housings.