摘要 |
A pivoting power transmission unit is provided for transmitting rotational drive from a power source to a rotor configured to revolve about a first axis and configured to swivel about a second axis perpendicular thereto. The transmission unit comprises: input pinion driven in rotation by the power source; two contra-rotating gearwheels which mesh with the input pinion and are co-axially mounted along the second axis; two cylindrical intermediate pinions, each joined to rotate co-axially with a respective one of the two gearwheels; and a further gearwheel in meshing engagement with the intermediate pinions. The further gearwheel drives in rotation an output shaft linked to the rotor. |