Linear sliding wave energy converter

We propose two methods to power autonomous ocean buoys by wave energy harvesting in deep ocean environments. Both concept include a linear sliding wave energy converter (LS-WEC), which consists of a translator and a rotary generator that works on angular motions, such as rolling and pitching due to ocean waves. The translator is a steel rod supported by wheels on rails with low-friction bearings. The translator linear motion is converted to rotary motion to spin an electric generator using either rack and pinion gears or a rope and pulley. The rack is fixed to a side face of the translator, the pinion is coupled to the generator shaft, and the mass is connected to an "electromagnetic spring". This artificial spring is realized by using the generator as a motor and performing feedback control of the mass displacement. With variable stiffness, the spring is used to tune the dynamic system in resonance with ocean wave motion so to maximize the power harvest.