Intra-tire power generating apparatus

Abstract

An intra-tire power generating apparatus capable of producing high power is provided. The apparatus includes rotary magnets and rotary weights, which rotate in response to variations in centrifugal force and circumferential acceleration working on the tire of a running vehicle, and a coil unit, which is located between two rotary magnets facing each other and generates voltages through electromagnetic induction from the rotary magnets. In the apparatus, the rotary magnets and the rotary weights have an identical center line of rotation. The rotary weights are so formed as to have their center of gravity dislocated from the center line of rotation. The rotary magnets are each provided, in the plane orthogonal to the center line of rotation, with an even number of regions adjoining in the circumferential direction around the center line of rotation, the adjoining regions having different magnetic poles from each other. The two rotary magnets facing each other are so configured as to rotate while maintaining the opposition of their respective regions having mutually opposite magnetic poles. And the coil unit has coil windings, each of which is of a tubular shape surrounding a space through which the magnetic flux generated between the mutually opposite magnetic poles of the two rotating rotary magnets passes.