Classifications

• • 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
  • F03D1/00—Wind motors with rotation axis substantially parallel to the air flow entering the rotor 
  • F03D1/06—Rotors
  • F03D1/065—Rotors characterised by their construction elements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
  • F01D5/12—Blades
  • F01D5/14—Form or construction
  • F01D5/16—Form or construction for counteracting blade vibration
• • 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
  • F03D7/00—Controlling wind motors 
  • F03D7/02—Controlling wind motors  the wind motors having rotation axis substantially parallel to the air flow entering the rotor
  • F03D7/0296—Controlling wind motors  the wind motors having rotation axis substantially parallel to the air flow entering the rotor to prevent, counteract or reduce noise emissions
• • 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
• • 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
  • F05B2240/00—Components
  • F05B2240/20—Rotors
  • F05B2240/30—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2240/00—Components
  • F05D2240/20—Rotors
  • F05D2240/30—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2260/00—Function
  • F05D2260/96—Preventing, counteracting or reducing vibration or noise
• • 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

• the present invention concerns a windmill blade with an arrangement for the damping of vibrations.
• a tuned vibration damper shall be understood to be an arrangement with a freely movable mass, which in an undamped manner can be accelerated at the beginning of a vibration phase, and is hereby capable of arriving at an opposing, fixed stop face just as the vibration changes to a counter- phase sequence, whereby the reverse vibration is counteracted by the whole of the kinetic energy of the moved mass.
• Fig. 1 is a plan view of a windmill blade which is provided near its top area with built-in containers for vibra- tion damping in accordance with the invention
• Fig. 2 is a perspective view of the relevant area, partly in section, and
• Fig. 3 is a schematic perspective view of just one of the relevant containers .
• the windmill blade 2 shown in fig. 1 is provided with a number of built-in, transversely-extending liquid containers 4 which more or less fill out the whole of the internal cavity in the blade in the relevant area.
• the breadth of the blade decreases outwards, and for precisely this reason use is made of several containers which can be of a breadth or transverse length which will be decreasing outwards.
• these contain- ers will be of a breadth which also decreases outwards.
• fig. 2 shows the shell construction of the blade with the outer end of an internal main beam 6 and with a number of containers 4 placed opposite the end of this beam.
• the containers 4 more or less fill out the inner cavity in the blade, whereby outwardly they decrease in both breadth and height.
• fig. 3 only three containers are shown, but in practice a considerably higher number can be involved, e.g. up towards fifty or more containers.
• the object will be for all of the containers to- gether to hold an amount of liquid which is so great that by its said swashing it can manifest sufficient kinetic energy to effectively counteract the natural frequency of the blade .
• a total liquid con- tent of 10-20 1 in the containers will be sufficient to achieve a good vibration damping against the natural vibrations contemplated, and precisely such a content will actually be able to be housed in half-filled containers 4 lying near the tip area of the blade.
• One of the containers 4 is shown schematically in fig. 3, in a situation where a liquid wave at the natural frequency of the blade has reached all the way forward to the left-hand end of the container. From here, the wave will return to a congruent formation at the opposite end, and hereby influence this almost in a blow-like manner for counteraction of the vibration.
• each individual container 4 When the frequency of the edgewise natural vibration for the relevant blade is known, together with the G-effect to which the container will be exposed when in operation, each individual container 4 must be filled with liquid for the tuning, e.g. in a vibration machine. When the G-effect is not known, the filling should be effected for tuning to a swash frequency which is the frequency of the natural vibration divided by the square root of the estimated G-effect.
• the damping containers are preferably built into the outermost end of the blade, e.g. in a pivotal tip part of the blade as indicated in fig. 1, and they can be completely built in because with said embodiment they can be provided as long-life units which do not require any form of maintenance. In areas with possible frost, the filling with liquid should naturally be frost-proofed, e.g. by using glycol .

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Buildings Adapted To Withstand Abnormal External Influences (AREA)
• Vibration Prevention Devices (AREA)
• Fluid-Damping Devices (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8104670

Family Applications (1)

Country Status (4)

Cited By (21)

Families Citing this family (2)

Citations (3)

• 1998
  • 1998-12-09 WO PCT/DK1998/000538 patent/WO1999032789A1/da active Application Filing
  • 1998-12-09 AU AU14840/99A patent/AU1484099A/en not_active Abandoned
  • 1998-12-09 DE DE19882884T patent/DE19882884T1/de not_active Ceased
• 2000
  • 2000-06-02 DK DK200000859A patent/DK173885B1/da not_active IP Right Cessation

Patent Citations (3)

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