Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H1/00—Toothed gearings for conveying rotary motion
  • F16H1/28—Toothed gearings for conveying rotary motion with gears having orbital motion
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03D—WIND MOTORS
  • F03D15/00—Transmission of mechanical power
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03D—WIND MOTORS
  • F03D15/00—Transmission of mechanical power
  • F03D15/10—Transmission of mechanical power using gearing not limited to rotary motion, e.g. with oscillating or reciprocating members
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03D—WIND MOTORS
  • F03D80/00—Details, components or accessories not provided for in groups F03D1/00 - F03D17/00
  • F03D80/70—Bearing or lubricating arrangements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
  • F05B2260/00—Function
  • F05B2260/40—Transmission of power
  • F05B2260/403—Transmission of power through the shape of the drive components
  • F05B2260/4031—Transmission of power through the shape of the drive components as in toothed gearing
  • F05B2260/40311—Transmission of power through the shape of the drive components as in toothed gearing of the epicyclic, planetary or differential type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H1/00—Toothed gearings for conveying rotary motion
  • F16H1/28—Toothed gearings for conveying rotary motion with gears having orbital motion
  • F16H2001/289—Toothed gearings for conveying rotary motion with gears having orbital motion comprising two or more coaxial and identical sets of orbital gears, e.g. for distributing torque between the coaxial sets
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/70—Wind energy
  • Y02E10/72—Wind turbines with rotation axis in wind direction

Definitions

• This invention relates to a drive assembly and to a gear transmission unit for a wind turbine.
• a wind turbine rotor drives the low speed shaft of a gear transmission unit, which transforms torque and speed of the rotor to the required torque and speed of an electrical generator.
• Integration of the components in a wind turbine is a way to reduce the weight and to make the drive assembly more compact, but it is important that the design and execution of the drive assembly avoids mutual interference of the external and internal loads on the different components. It is also important that the construction of an integrated drive assembly allows effective lubrication to be achieved economically and reliably.
• the present invention seeks to provide an improved drive assembly and an improved gear transmission unit for a wind turbine and which permits an advantageous integration of components.
• a drive assembly for a wind turbine comprises 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, said ring gear being non-rotatably secured to said supporting structure, a main bearing which is a double taper bearing and rotatably supports the rotor hub 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 via said main bearing to the supporting structure primarily for transmission of overhang load forces and bending moment forces and a second of said force transmission paths acting from the rotor hub via said planet carrier primarily for transmission of rotational forces.
• Said main bearing may also rotatably support the planet carrier relative to said ring gear and supporting structure.
• Said double taper bearing may comprise a single outer bearing ring.
• the rotor hub may be rigidly secured relative to said single outer bearing ring.
• the double taper bearing may comprise rollers arranged in an O configuration in which the rollers of one series increase in diameter in a direction away from the rollers of the other series of the pair.
• the invention teaches that the overhung load forces and bending moments from the rotor are taken by a double taper bearing which is directly connected to stationary parts instead of to the torque transmitting low speed part of the gear unit.
• said main bearing lies at a position substantially aligned axially with the axial position of at least the ring gear of the gear transmission unit.
• the sun, planet and ring gears lie in a transverse plane (perpendicular to the rotation axis of said rotational forces) which also contains said main bearing.
• the main bearing comprises an inner ring bearing surface of a diameter greater than that of the toothed surface of the ring gear, and that at all radial positions inwards of the toothed surface of the ring gear the second force transmission path is substantially independent of the first force transmission path.
• the second of said force transmission paths comprises a radially extending torque transmission member which is torsionally stiff but relatively compliant in an axial direction parallel with the axis about which the rotational forces act whereby movement of the hub in consequence of bending forces is accommodated at least in part by deflection of the torque transmission member.
• the torque transmission member thereby isolates the gear transmission unit from the potentially damaging effects of bending deflections experienced by the rotor hub relative to the main rotational axis of the gear transmission unit.
• the present invention accordingly provides, in a further of its aspects, a drive assembly in which the main rotor bearing and gear transmission unit for a wind turbine are of an integrated construction.
• the wind turbine rotor hub preferably is connected to the outer ring of the main bearing.
• the bearing inner ring preferably is supported by, and may be directly mounted on, the ring gear of the planetary gear stage, or on a flange which connects the ring gear to the supporting structure.
• the ring gear may provide a bearing surface for rotatable bearing components of the main bearing.
• the ring gear may provide axial and radial locations for the main bearing.
• the ring gear may have a radially outer surface of a stepped profile to define a shoulder for axial location of an inner bearing ring of the main bearing.
• the inner bearing ring may be secured axially between said shoulder and said supporting structure.
• the ring gear may be provided with a reinforcing ring, and said reinforcing ring may extend axially and or radially beyond the toothed surface of the ring gear. Said reinforcing ring may provide an axial location of the main bearing.
• the present invention provides a wind turbine comprising rotors, a generator and a drive assembly of a type in accordance with the present invention.
• the gear transmission unit e.g. a housing thereof, may be arranged to support an electrical generator.
• Figure 1 is an elevation view of a wind turbine having a drive assembly of the present invention
• Figure 2 is a sectional view of part of a gear transmission unit
• FIG. 3 shows part of Figure 2 in more detail
• FIGS 4, 5 and 6 each show variations of the construction of Figures 2 and 3;
• FIG. 7 shows part of Figure 6 in more detail
• FIGs 8 and 9 each show further variations of the construction of Figures 2 and 3.
• a wind turbine 10 (see Figure 1) comprises a gear transmission unit 11 which acts to transmit torque from rotor blades 12 and rotor hub 14 to an electrical generator 13, the gear transmission unit comprising an epicyclic gear unit.
• the gear transmission unit and generator are housed in and supported by a nacelle 15.
• the gear transmission unit 11 is now described in more detail with reference to Figures 2 and 3.
• the gear transmission unit 11 comprises an epicyclic gear unit having four planet gears 25, a sun gear 27 a planet carrier 28, and a ring gear 24 which is non-rotatably mounted relative to the nacelle structure 15.
• the sun gear is connected to an output shaft (not shown) which connects either to a further gear unit or direct to the rotor of the generator 13.
• the radially outer surface 29 of the ring gear 24 provides location and support for the inner ring 30 of a main bearing 23.
• the outer ring 31 of the main bearing has secured thereto the rotor hub 14 and, interposed between the rotor hub and ring 31, the outer region 22 of the planet carrier 28.
• the planet carrier 28 comprises four bearing support studs 26 uniformly circumferentially spaced to locate bearings 32 which rotatably support the four planet gears 25.
• the planet carrier 28 has an annular region 33 which extends radially between the radial position of the bearing studs 26 and the outer region 22 and is designed to be relatively stiff, in a circumferential direction about the Y axis, for transmission of torque between the region 22 and the bearing studs 26, but to be relatively flexible about the X and Z axis.
• Figure 4 shows a variation 40 in which the planet carrier 41 is provided with three integral and uniformly circumferentially spaced studs 42 which support a planet bogie plate 43.
• the planet bogie plate 43 provides support for three circumferentially uniformly spaced shafts 44 arranged each to self adjust in angular position on the plate 43.
• Each shaft 44 provides support, at opposite sides if the plate 43, for a pair of bearings 45, 46 about which each of a pair of planet gears 47, 48 are rotatably mounted for engagement with the ring gear 49.
• the planet carrier 56 is of a cage type design.
• each of three planet bearing support shafts 51 is supported at one axial end 52 by the part 53 of the planet carrier that extends radially outwards to be supported by the outer ring of the main bearing 54 whilst the other end 55 is supported by an auxiliary driving plate 57 carried by three circumferentially uniformly spaced supports 58 provided at positions interposed circumferentially between the shafts 51.
• the plate 57 is provided with a central aperture 59 to which an output shaft 60 extends from the sun gear 61.
• Figure 6 shows an embodiment of the present invention and which is a further variation of the construction of Figures 2 and 3.
• the planet carrier is constructed substantially similar to that described with reference to Figure 5.
• the ring gear 63 differs in so far as part of the outer periphery of the gear is surrounded by a reinforcing support ring 64.
• the reinforcing ring is either formed integrally, e.g. forge rolled, with the outer ring 63 or permanently secured thereto, for example by being a shrink fit thereon.
• the presence of the support ring, provided axially at a position spaced from the nacelle structure 15 provides an abutment surface 65 for axial location of the inner ring of the main bearing 66.
• the main bearing 66 is a double taper type bearing, shown in more detail in Figure 7.
• the main bearing comprises an inner ring of a split construction comprising two taper rings 67.
• the bearing additionally comprises a single outer ring 68 of double taper form.
• Figure 8 A further variation of the construction of Figures 2 and 3 is shown in Figure 8.
• the inner ring of the main rotor bearing 81 contrasts with aforedescribed constructions in so far as it is not directly mounted on or supported by the ring gear 82. Instead, the inner ring of the bearing 81 is supported by a flange assembly 83 secured to the nacelle structure 15.
• the bearing inner ring is connected substantially directly to the nacelle structure 15 at position 91.
• the sun, planet and ring gears are all substantially aligned with one another as considered in an axial direction parallel with the axis of rotation of the planet carrier.
• the main bearing comprises an inner ring bearing surface the diameter of which is greater than that of the toothed surface of the ring gear.
• a benefit arising from the drive assembly, and the gear transmission unit of the present invention as used in a wind turbine is that the overhung loads generated by the wind turbine rotor blades have only a minimal effect on the planet driving components and on the gear meshing contact of the planetary gear stage. This allows for an increased power rating of the gear transmission unit or a reduction of dimension for a given power rating as compared with hitherto known constructions. It is also to be appreciated that the forces generated in gear meshing of the planets have only a minimal effect on the load distribution over the bearing rollers in the main bearing, thus increasing the load capacity of the main bearing or allowing for reduction of dimensions of that bearing for a given load capability.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Retarders (AREA)
• Wind Motors (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=9919776

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Cited By (1)

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• 2001
  • 2001-08-03 GB GBGB0118996.8A patent/GB0118996D0/en not_active Ceased
• 2002
  • 2002-08-01 US US10/485,563 patent/US20040213671A1/en not_active Abandoned
  • 2002-08-01 EP EP02767773A patent/EP1423608A1/de not_active Withdrawn
  • 2002-08-01 WO PCT/IB2002/003672 patent/WO2003014567A1/en not_active Application Discontinuation

Non-Patent Citations (1)

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