Patent ID: 6915983

Claim:
A pivoting power transmission unit for driving a rotor, comprising a casing pivoting about a pivot axis on a non-pivoting support, said casing comprising a lower-casing, which encloses at least one stage of gears of the transmission unit, and by which said casing is mounted so as to pivot on said support by two bearings coaxial about said pivot axis and spaced apart from each other therealong, each bearing having a stationary part, integral with said support, and a swivelling part, integral with said lower casing, and mounted so as to rotate on said corresponding stationary part about said pivot axis, said casing also comprising an upper casing, assembled to the lower casing, and in which a drive shaft, connected in rotation to said stage of gears, is mounted so that it can rotate about an axis of rotation substantially perpendicular to said pivot axis and pivoting with said casing about said pivot axis, said drive shaft being retained axially by at least one thrust bearing in a part of said upper casing having a generally convergent external shape, which converges towards one end of said drive shaft projecting out of said casing and connected in rotation to said rotor, wherein said upper casing cooperates with an arrangement configured to transfer to said support via said pivot bearings at least an axial load experienced by said drive shaft during use, said arrangement extending outside said pivoting casing.