초록 ▼

A fixed pitch wind turbine rotor (18) is teeter mounted (76, 78, 80) onto a low speed input shaft (44) which is connected to the input (58) of a step-up transmission (46). The output (48) of the transmission (46) is connected to a rotary pole amplitude modulated induction machine (42) which is opera

A fixed pitch wind turbine rotor (18) is teeter mounted (76, 78, 80) onto a low speed input shaft (44) which is connected to the input (58) of a step-up transmission (46). The output (48) of the transmission (46) is connected to a rotary pole amplitude modulated induction machine (42) which is operable as a generator at a plurality of discreet speeds of rotation and is also operable as a startup motor for the rotor. A switch (45) responsive to the rotational speed of the wind turbine rotor switches the generator from one speed of operation to the other. The rotor hub (72) and the inner body portions (71) of two blades (68, 70), which extend radially outwardly in opposite directions from the hub (72), are constructed from steel. The outer end portions (73) of the blade (68, 70) are constructed from a lighter material, such as wood, and are both thinner and narrower than the remainder of the rotor. The outer end section (73) of each blade (68, 70) includes a main body portion and a trailing edge portion (104) which is hinge-connected to the main body portion. Each blade (68, 70) includes a centrifugal force operated positioning means (98, 100) which normally holds the drag brake section (104) in a retracted position, but operates in response to a predetermined magnitude of centrifugal force to move the drag brake (104) section into its deployed position. Each blade has an airfoil cross section and each blade (68, 70) has a plus twist inner portion adjacent the hub (72) changing to first a zero twist and then a minus twist as it extends radially outwardly from the hub (72).

대표청구항 ▼

A wind turbine system for generating electricity, comprising: a wind turbine rotor; a rotor shaft connected to said hub for rotation with said wind turbine rotor; a step-up transmission having a low speed input connected to said rotor shaft and a high speed output; a rotary pole amplitude modulated

A wind turbine system for generating electricity, comprising: a wind turbine rotor; a rotor shaft connected to said hub for rotation with said wind turbine rotor; a step-up transmission having a low speed input connected to said rotor shaft and a high speed output; a rotary pole amplitude modulated induction machine having a rotor that is connected to the output of said transmission, said machine being operable as a generator at a plurality of discreet speeds of rotation; wind speed responsive switch means for changing speed of operation of said induction machine; and wherein said wind turbine rotor comprises an elongated central hub with no twist having rounded edges and a substantially constant thickness between the edges; a pair of fixed pitch essentially straight blades, each blade extending radially outwardly from said hub in a direction diametrically opposite from the other blade; each said blade having a mid-section of airfoil cross section positioned radially outwardly of said central hub portion, and a tip section of airfoil cross section positioned radially outwardly of the mid-section; each said blade smoothly changing from the substantially constant thickness and rounded edge shape of the central hub portion into an airfoil cross section as it extends radially outwardly from the central hub portion; each blade first changing to first a plus twist and then a zero twist and then a minus twist as it extends radially outwardly; each said blade tapering in thickness and chord as it extends radially outwardly from a location in its mid-section through its tip section; and wherein the tip section of each said blade includes a sculptured tip end portion which decreases in thickness as it extends radially outwardly , said tip portion having an aerodynamic cross-sectional shape which progressively decreases in size, and having a leading edge which progressively sweeps rearwardly.