1. Field of the Invention
The present invention relates, in general, to an electric generator using a permanent magnet in a shape of a tapered cone, especially, one which induces a useful equilibrium of magnetic force and, more particularly, to a magnetically balanced electric generator, in which a power-generating core unit and a power-generating magnet are spaced apart at constant intervals using a magnetically repulsive force, which is caused by a permanent magnet shaped like a tapered cone, and a magnetically attractive force, which is caused between the power-generating core unit and a power-generating magnet, and the interval is controlled depending on the intensity of wind, thereby improving power-generation efficiency, the lifetime of parts, and economical efficiency of products.
2. Description of the Related Art
Generally, an electric generator means a device that includes a rotor which rotates under external force, a fixing structure supporting the rotor, and an electricity-generating unit which operates upon rotation of the rotor. However, bearings of such electric generators have a problem in that a certain amount of oil should be regularly supplied to the bearings and the contamination of foreign substances causes damage to the bearings.
Further, in case of wind turbines using wind power as an external force, an electrical-connection controller should be installed in order to generate electricity as expressed by the formula E=Cp×(½)×ρ×A×v3, which however is difficult work, and thus problems such as the complexity of parts, burning-out of electric parts or the like occur. Wind turbines are the hardest kinds of electric generators to design because they have to deal with energy proportional to cubic wind velocity.
Meanwhile, the applicant developed a new construction electric generator in consideration of the fact that existing vertical type wind generators do not sufficiently utilize wind power, which generator was disclosed in Korean Patent Registration No. 0743475.
FIG. 1 shows the structure of the electric generator in a cross-sectional view.
The disclosed electric generator is called a variable electric generator for a wind turbine, which includes a group 11 of magnets which is installed on a lower end of a rotor 10 rotating with the wind, a plurality of core units 21 which is installed in a fixing structure in such a manner as to be arranged concentrically with the magnets of the group and which upon rotation of the rotor 10 interacts with the magnets to thereby generate electricity, an anemometer 30 detecting the magnitude of wind velocity, an electric accumulator 40 storing electricity generated by the core unit 21, and a terminal 50 connecting the respective core units 21 and the electric accumulator together such that the core units are selectively connected with the electric accumulator according to the wind velocity detected by the anemometer 30.
The variable electric generator of this type changes a power-generating condition depending on the intensity of wind, having such advantages as more efficiently utilizing wind power.
In the meantime, in order to generate electricity using interaction between the power-generating magnet and the core unit, in which a coil is wound around a silicon steel plate, an interval between the power-generating magnet and the core unit should be maintained to approximately 1 mm. Then, since the interval is maintained by a spherical steel bearing 61, which is mounted between the rotor and the fixing structure, the bearing should be periodically lubricated so that the interval can be maintained accurately and efficiently, which is troublesome work, otherwise the bearing may burn out during use, problematically requiring replacement with new one.
Furthermore, problems such as contact points burning out during manipulation of the power-generating coil, which may result in a reduction in lifetime, may occur.