US 8476782 B2 / Jul 2, 2013

WEC with improved power take off apparatus

A wave energy converter (WEC) includes a float and a spar for guiding the up and down movement of the float in response to the waves. A power take off (PTO) device coupled between the float and the spar and mounted within one of the float and spar such that the PTO includes apparatus responsive to the mechanical interaction of the float with the portion of the spar in proximity to the float for converting their relative motion into useful energy. In one embodiment the PTO includes a linear rack extending along an external portion of the spar and a linear to rotary converter, mounted within the float, including a double sided toothed belt for engaging the rack and causing rotation of the rotary converter to drive an electric generator. In another embodiment the PTO includes tires mounted within the float which rotate as the float moves up and down. In another embodiment the PTO includes a rack and pinion arrangement with one of them connected to the spar and the other mounted in the float.