Fluid driven turbine
A fluid turbine comprises a rotor rotatable in use about an axis transverse to the direction of fluid flow. The rotor has a first part carrying a plurality of arcuate blades and a second part journalled in a base structure by means of two or more bearings. All the bearings are arranged on the same side of the blades so that the first part of the rotor is cantilever supported in the base structure.
1. A fluid turbine comprising:
a base structure having a plurality of bearings disposed therein; and
a rotor having a first part and a second part that are rotatable about an axis transverse to the fluid flow, the first part carrying a plurality of substantially arcuate blades, and the second part being journaled in the plurality of bearings;
wherein the plurality of bearings are arranged on the same side of the blades, whereby the first part of the rotor is cantilever supported by the bearings.
2. The fluid turbine of claim 1 wherein the first part of the rotor is tapered, reducing gradually in diameter with increasing distance from the base structure.
3. The fluid turbine of claim 1 , wherein brakes, a control system and a generator are contained within the base structure.
4. The fluid turbine of claim 3 wherein the control system and generator are removable from the base structure as a sub-assembly.
5. The fluid turbine of claim 3 wherein the sub-assembly further incorporates at least one brake disc and at least one brake calipers.
6. The fluid turbine of claim 1 wherein a rotating anemometer is mounted to the rotor for the purposes of fluid speed sensing.
7. The fluid turbine of claim 6 , wherein a processing circuit is provided to compensate the output of the anemometer for the rotational speed of the rotor.
8. The fluid turbine of claim 3 wherein the lowest resonant frequency of the turbine assembly is greater than the frequency of excitation caused by rotational imbalance in the blades and wind loading at all speeds permitted by the control system.
9. The fluid turbine of claim 1 wherein at least one of the plurality of bearing is substantially free to move axially relative to one of the rotor and the base structure while preventing the rotor from moving radially relative to the base structure.
10. The fluid turbine of claim 1 wherein a tuned mass damper is disposed on the same side of the bearings as the blades and is attached to the rotor for rotation with the blades, the tuned mass damper being designed to attenuate resonant vibrational motion of the blades and of the rotor.
11. The fluid turbine of claim 10 wherein a viscous or frictional damping mechanism is additionally provided for damping the motion of the tuned mass damper.