Patent ID: 11859716
Assignee: UNIVERSITY OF MARYLAND, BALTIMORE
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F  Y | IPC F

Claim 16:
17. A tidal current energy converter (TCEC) comprising: (i) at least one infinitely variable transmission (IVT) comprising an IVT control system comprising a crank length controller, a forward speed controller, or both; and (ii) at least one vertical axis water turbine (VAWT), wherein the VAWT is a hybrid VAWT comprising:
(a) a first rotor system positioned in a central region and rotatable about a central axis, wherein the first rotor system comprises:
(i) at least two blade-sets stacked vertically along the central axis, each blade-set comprising a plurality of first blades that are spaced about the central axis, wherein the at least two blade-sets are mounted upon a shaft with bearings along the central axis, wherein each first blade extends from a position proximate to the central axis out to a position distal to the central axis and has a concave shape that allows fluid to push on a concave side of each first blade, and
(ii) a hydraulic brake system that is mounted upon the shaft with bearings; and

(b) a second rotor system positioned in an annular region surrounding the first rotor system in the central region, wherein the second rotor system comprises a plurality of second blades spaced about the central axis, wherein each of the second blades is positioned substantially parallel to the central axis and attached to at least one blade-set of the first rotor system using at least two supporting struts, wherein the cross-section of the second blade is a substantially symmetrical airfoil shape.