A tidal power generator with a vertical axis transverse flow rotor

A tidal power generator comprises a vertical axis transverse flow rotor and a cam ring pump where the power is taken off the rotor via the cam ring which communicates with the rim of the rotor. The rotor may be neutrally or positively buoyed and fixed to the seabed by mooring lines. The ring cam (figure 2) may be annular and comprise separate lobes tensioned together; the lobes projecting in up to four directions, each to drive a set of pumps. The rotor may further comprise variable pitch blades where the pitch angle is controlled by the moment of the blades around a pitch angle and generated by a fluid pressure in a manifold common to all blades. The pumps and ring cam may be housed in a toroid located above the rotor at the rim. The rotor itself may be 50m in diameter, 20m deep, have 3 banks of blades and be stiffened by streamlined diagonal ties.