Patent ID: 8187133

Claim:
An automatic planetary transmission comprising: a rotatable shaft having an outer peripheral surface, said shaft extending along a central axis and being adapted to be drivingly connected to a power source; and a lubrication system for transporting lubrication oil in the automatic transmission, said lubrication system including: an axial lubrication passage extending within the rotatable shaft along the central axis; and a radial lubrication passage extending from the axial lubrication passage, along a transverse axis to the central axis, to the outer peripheral surface, with said radial lubrication passage opening at a hole in the outer peripheral surface, said hole having a cross section that is elongated only along a first axis offset from the central axis so as to follow angular deformation caused by unidirectional torque applied to the shaft whereby stress produced around the hole by torque transmitted through the rotating shaft is reduced, thus minimizing fatigue and increasing a useful life of the automatic planetary transmission.