Aerodynamic lifting device

1. An aerodynamic lifting device comprising:

a chassis;

a rotor of a radial drum or centrifugal fan supported by the chassis having a rotational axis and a plurality of rotor blades disposed in an annular ring about the rotational axis;

a torque transmission means for rotating the rotor comprising a plurality of prime movers for generating tractive force arranged at spaced intervals of arc about the rotational axis of the rotor, each prime mover being connected to a corresponding torque transmitting device for providing tractive force for rotating said rotor and each prime mover and corresponding torque transmitting device being arranged in pairs about the rotational axis of the rotor; and

a circumferentially extending drive rim for the rotor having a circumferentially extending inner drive surface and a circumferentially extending outer drive surface, each drive surface being engageable with a complementary torque transmitting device of each said pair of torque transmitting devices for transmitting tractive force as tangential forces and resultant torque to drive the rotor and generate lift;

wherein said circumferentially extending drive rim is disposed between and rotatable by said paired torque transmitting devices.

2. The aerodynamic lifting device as claimed in claim 1 wherein said inner and outer surfaces of said drive rim and said paired torque transmitting devices are each provided with complementary grooved geometry, said inner and outer surfaces having a plurality of circumferentially extending grooves for meshing with complementary grooves of said torque transmitting devices.

3. The aerodynamic lifting device as claimed in claim 1 wherein said torque transmitting devices are biased into position against said drive rim by a loading means to restrain the position of the rotor.

4. The aerodynamic lifting device as claimed in claim 3 wherein said loading means is a spring having spring force to develop a frictional force required to transmit torque to the rotor.

5. The aerodynamic lifting device as claimed in claim 1 wherein said torque transmitting devices and prime movers are fixed to said chassis by restraints.

6. The aerodynamic lifting device as claimed in claim 5 wherein said restraints include damping means.

7. The aerodynamic lifting device as claimed in claim 1 wherein each prime mover and torque transmitting device of said torque transmission means is pivotally mounted on said chassis.

8. The aerodynamic lifting device as claimed in claim 1 wherein said chassis is of toroidal shape.

9. The aerodynamic lifting device as claimed in claim 8 wherein said chassis is buoyant.

10. The aerodynamic lifting device as claimed in claim 8 wherein said toroidal shaped chassis is provided with a guide surface to guide airflow exiting from the rotor of the fan and vector thrust.

11. An aerodynamic lifting device comprising:

a chassis;

a rotor of a radial drum or centrifugal fan supported by the chassis having a rotational axis and a plurality of rotor blades disposed in an annular ring about the rotational axis;

a torque transmission means for rotating the rotor comprising a plurality of prime movers for generating tractive force arranged at spaced intervals of arc about the rotational axis of the rotor, each prime mover being connected to a corresponding torque transmitting device for providing tractive force for rotating said rotor and each prime mover and corresponding torque transmitting device being arranged in pairs about the rotational axis of the rotor, such that, on operation of the torque transmission means lift is generated wherein said chassis for supporting said rotor and transmission means is of toroidal shape; and

a circumferentially extending drive rim for the rotor having a circumferentially extending inner drive surface and a circumferentially extending outer drive surface, each drive surface being engageable with a complementary torque transmitting device of each said pair of torque transmitting devices for transmitting tractive force as tangential forces and resultant torque to drive the rotor and generate lift;

wherein said circumferentially extending drive rim is disposed between and rotatable by said paired torque transmitting devices.

12. The aerodynamic lifting device as claimed in claim 11 , wherein said chassis is buoyant for waterborne use, having buoyancy to elevate said rotor above a water surface during take off and landing.

13. An airborne craft incorporating the aerodynamic lifting device of claim 1 and comprising a shroud having a flexible skirt attached to an area around a top part of the rotor to provide altitude, thrust and directional control of the airborne craft.

14. The airborne craft incorporating the aerodynamic lifting device of claim 11 , comprising a shroud having a flexible skirt attached to an area around an top part of the rotor to provide altitude, thrust and directional control of the airborne craft.

15. The airborne craft as claimed in claim 13 , wherein the shroud has a fluid exit region defined by a plurality of shroud portions in the form of movable petals.

16. The airborne craft as claimed in claim 14 , wherein the shroud has a fluid exit region defined by a plurality of shroud portions in the form of movable petals.

17. The aerodynamic lifting device as claimed in claim 1 wherein a first torque transmitting device of said paired torque transmitting devices is engageable with said circumferentially extending inner surface of said drive rim and a second torque transmitting device of said paired torque transmitting devices is engageable with said circumferentially extending outer surface of said drive rim.

18. The aerodynamic lifting device as claimed in claim 1 wherein a prime mover and a torque transmitting device of each said pair of torque transmitting devices are disposed at the same point on opposite sides of said circumferentially extending drive rim.