2017 年 83 巻 853 号 p. 17-00093
In this paper, a mechanism consisted of a double-cone rolling on two divergent-convergent rails is proposed to be used in the construction of a wave-powered electrical generator. Such divergent-convergent rails, attached to a buoy, can be materialized by using either straight V-rails, or eccentric circular rails. Rotational movement of the buoy, induced by the waves, is transformed into the rotational and translational motion of a magnetized double-cone. In this way, a variable magnetic field is extended over several coils, connected in parallel. Power generation is obtained through the electromagnetic induction effect. Firstly, a geometrical model is proposed to determine the length and radii of contact between the double-cone and the circular rails. Variation of the number of rotations, theoretically obtained, versus the rails eccentricity is validated by tests, where a double-cone, made in S45C carbon steel, is rolling on circular rails, made of A5052 aluminum alloy. Then, a model to evaluate the pressure of contact, and the change of potential energy of the double cone, is advanced. Based on such model, variation of the maximal contact pressure versus the rails eccentricity is clarified, for various loading patterns, corresponding to waves of different heights.