WO2008147220A1 - Noise reduction in epicyclic gear systems - Google Patents
Noise reduction in epicyclic gear systems Download PDFInfo
- Publication number
- WO2008147220A1 WO2008147220A1 PCT/NZ2007/000130 NZ2007000130W WO2008147220A1 WO 2008147220 A1 WO2008147220 A1 WO 2008147220A1 NZ 2007000130 W NZ2007000130 W NZ 2007000130W WO 2008147220 A1 WO2008147220 A1 WO 2008147220A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- gear
- planet gears
- epicyclic
- spindle
- planets
- Prior art date
Links
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
- F16H1/2809—Toothed gearings for conveying rotary motion with gears having orbital motion with means for equalising the distribution of load on the planet-wheels
- F16H1/2836—Toothed gearings for conveying rotary motion with gears having orbital motion with means for equalising the distribution of load on the planet-wheels by allowing limited movement of the planets relative to the planet carrier or by using free floating planets
-
- 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
- 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
- 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
- F05B2260/96—Preventing, counteracting or reducing vibration or noise
-
- 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
- F16H57/00—General details of gearing
- F16H57/08—General details of gearing of gearings with members having orbital motion
- F16H57/082—Planet carriers
-
- 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 epicyclic or planetary gear systems, in particular but not only to a system for use in reducing noise from wind turbines.
- Wind turbines are increasingly used to capture and convert wind energy into electricity. Recent improvements in the design of these turbines have lowered their cost to the point where they are now commercially viable as alternatives to other sources of power. However, where the turbines are located near populated areas, the noise that they also generate is often a sensitive planning issue.
- Wind turbines normally use epicyclic gearboxes and these may be more or less noisy depending on a number of factors, such as the choice of straight-cut versus helical gears, the quality of the gears (accuracy and surface finish), the precision of the overall gearbox design (concentricity of bearing housings etc), and detailed modifications to the involute gear shape (tip and root relief).
- the design of the casing that surrounds the gearbox and other parts of the turbine also plays an important role, and heavier casings will normally be quieter. Rubber mounting of the gearbox can be useful in some cases. Avoiding resonances in the drive- train or in the casing and its mounting to the supporting structure, is also important.
- a quiet epicyclic gearbox for a wind turbine would have: helical gears, a high quality surface finish, high precision in the overall gearbox design and manufacturing, tip and root relief optimized to minimize vibration at critical loadings (typically 40% of rated for a wind turbine because of the beneficial masking effect of wind noise at higher loadings), a heavy casing, be rubber mounted, and avoid any resonances.
- critical loadings typically 40% of rated for a wind turbine because of the beneficial masking effect of wind noise at higher loadings
- a heavy casing be rubber mounted, and avoid any resonances.
- planeet phasing One approach for reducing vibration and noise in epicyclic systems.
- the planet configuration and tooth numbers are chosen so that the net forces and torques on the sun and ring gears, and on the carrier of the planet gears, are reduced by self equilibration. Previous attempts to implement phasing have produced reductions in vibration and noise for helicopters and other engines, but due to imperfections in the gear systems the results were not sufficiently quiet to be helpful for wind turbines.
- the invention resides in a epicyclic gear system, including: a sun gear, a ring gear and P planet gears, all contained by a casing, wherein the planet gears include load equalisation means, and wherein P >3 and 1 ⁇ K 1 (as defined below) ⁇ P-1.
- the load equalisation means includes a flexible spindle, and more preferably a compound cantilevered spindle, for each of the planet gears.
- Figures Ia to Id show end views of a range of epicyclic gear systems
- Figure 2 is a cross sectional view through an eight planet system with load equalisation
- FIG 3 is a detailed cross-sectional view through one of the planet gears in Figure 2
- Figure 4 shows operation of the flexible spindle in Figure 3. - A -
- K modulus[hN s /P] where: h is the number of the harmonic of gear mesh frequency potentially being excited (1 st , 2 nd , 3 rd etc), N s is the number of teeth on the sun gear, P is the number of planets.
- K-factor has values 0, 1, 2...(P-I).
- Figures Ia- Id show a range of epicyclic gear systems which have demonstrated the noise reduction possibilities of the invention.
- a flexible spindle typically involves the use of a compound cantilever so that the planet teeth remain parallel along the gear-mesh even as the spindle flexes.
- the spindle itself is sufficiently flexible that, under design loadings, its deflection is an order of magnitude greater than the possible cumulative machining errors which would otherwise cause unequal loading.
- a typical deflection might be around 0.5 mm for example, whereas cumulative machining errors would be 0.05-0.10 mm.
- Figures 1 a and 2 are end and cross sectional views showing the main components of an epicyclic gear system .
- the system includes a central or sun gear 20 surrounded by eight planet gears 21 mounted on respective bearings 22. Only two of the planet gears can be seen in Figure 2.
- a planet carrier 23 supports the planet gears through respective pins or spindles 24 and bobbins.
- An annulus gear or casing 25 surrounds the planet gears.
- the planet gears engage the sun gear and the annulus gear through gearmeshes 26.
- One way to enable load sharing in this system is to provide flexible spindles for each or at least some of the planet gears. A range of spindle designs are possible.
- Figures Ib, Ic, Id show epicyclic systems for comparison with Figure Ia and which can be considered in relation to details given in the table above.
- Figure 3 is a cross section showing one of the planet gears 21 in more detail, in an unloaded condition.
- the spindle 24 is made flexible by way of a compound cantilevered arrangement.
- One end 30 of the spindle is fixed to the planet carrier 23 while the other end 31 is fixed to the planet gear.
- the centre region of the spindle is spaced from the centre of the planet gear by a clearance region 33 having a width sufficient for the loading which is expected in normal use.
- Figure 4 shows how the planet gear in Figure 3 behaves under load.
- the gearmesh 26 imposes tangential and radial loads on the gear, the load is transmitted through the bearings 22 to a cantilevered bobbin. This imposes a bending deflection on the spindle within the clearance space 33.
- the spindle has much lower bending stiffness than the bobbin. Since the spindle in turn is cantilevered from end 31, there are two angular deflections of opposite sense imposed on the spindle.
Landscapes
- 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)
- Wind Motors (AREA)
- Retarders (AREA)
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU2007354405A AU2007354405B2 (en) | 2007-05-29 | 2007-05-29 | Noise reduction in epicyclic gear systems |
PCT/NZ2007/000130 WO2008147220A1 (en) | 2007-05-29 | 2007-05-29 | Noise reduction in epicyclic gear systems |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/NZ2007/000130 WO2008147220A1 (en) | 2007-05-29 | 2007-05-29 | Noise reduction in epicyclic gear systems |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2008147220A1 true WO2008147220A1 (en) | 2008-12-04 |
Family
ID=40075308
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/NZ2007/000130 WO2008147220A1 (en) | 2007-05-29 | 2007-05-29 | Noise reduction in epicyclic gear systems |
Country Status (2)
Country | Link |
---|---|
AU (1) | AU2007354405B2 (en) |
WO (1) | WO2008147220A1 (en) |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3303713A (en) * | 1964-02-07 | 1967-02-14 | Nat Res And Dev Corp | Load equalizing means for planetary pinions |
US4700583A (en) * | 1982-05-01 | 1987-10-20 | Hicks Transmissions Limited | Gear mounting |
JPH10230491A (en) * | 1998-03-13 | 1998-09-02 | Teijin Seiki Co Ltd | Planetary gear reduction gear |
EP1214535B1 (en) * | 1999-09-25 | 2003-05-07 | ZF FRIEDRICHSHAFEN Aktiengesellschaft | Planetary gear for lifting devices |
US6682456B2 (en) * | 2001-12-10 | 2004-01-27 | Axicon Technologies, Inc. | Multi-mesh gear system |
US6898975B2 (en) * | 2003-01-24 | 2005-05-31 | The Defence Science And Technology Organization Of The Department Of Defence On Behalf Of The Commonwealth Of Australia | Synchronous averaging of epicyclic sun gear vibration |
US7115066B1 (en) * | 2002-02-11 | 2006-10-03 | Lee Paul Z | Continuously variable ratio transmission |
-
2007
- 2007-05-29 AU AU2007354405A patent/AU2007354405B2/en not_active Ceased
- 2007-05-29 WO PCT/NZ2007/000130 patent/WO2008147220A1/en active Application Filing
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3303713A (en) * | 1964-02-07 | 1967-02-14 | Nat Res And Dev Corp | Load equalizing means for planetary pinions |
US4700583A (en) * | 1982-05-01 | 1987-10-20 | Hicks Transmissions Limited | Gear mounting |
JPH10230491A (en) * | 1998-03-13 | 1998-09-02 | Teijin Seiki Co Ltd | Planetary gear reduction gear |
EP1214535B1 (en) * | 1999-09-25 | 2003-05-07 | ZF FRIEDRICHSHAFEN Aktiengesellschaft | Planetary gear for lifting devices |
US6682456B2 (en) * | 2001-12-10 | 2004-01-27 | Axicon Technologies, Inc. | Multi-mesh gear system |
US7115066B1 (en) * | 2002-02-11 | 2006-10-03 | Lee Paul Z | Continuously variable ratio transmission |
US6898975B2 (en) * | 2003-01-24 | 2005-05-31 | The Defence Science And Technology Organization Of The Department Of Defence On Behalf Of The Commonwealth Of Australia | Synchronous averaging of epicyclic sun gear vibration |
Non-Patent Citations (1)
Title |
---|
DATABASE WPI Derwent World Patents Index; Class Q64, AN 1998-524825/45 * |
Also Published As
Publication number | Publication date |
---|---|
AU2007354405A1 (en) | 2008-12-04 |
AU2007354405B2 (en) | 2012-09-13 |
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