Patent ID: 6799416
Filing Date: 2004-10-05
Classification: F01D,F05B,F05D,F16C

Abstract:
A device for radially supporting the front (1) of a drive shaft (2) for a fan (3) of a turbojet of longitudinal axis X, the axis (11) of said shaft (2) normally coinciding with said longitudinal axis X, the device comprising a stationary annular support (4) surrounding said shaft (2), a support bearing (5) disposed between said shaft (2) and said support (4) and presenting an outer ring (8) that is stationary in rotation and an inner ring (9) that moves in rotation with said shaft (2), fusible means interposed radially between one of said rings (8, 9) and the adjacent part of the assembly constituted by said shaft (2) and said support (4) and designed to break on the appearance of a radial load F of magnitude greater than a predetermined threshold Fm so as to release said shaft (2) radially relative to said support (4), and means for recentering the axis (11) of the shaft (2) on the longitudinal axis X of the turbojet after said fusible means have broken,the device being characterized by the fact that the radially fusible means comprise two sectorized annular webs or tenons (14a, 14b) provided in the respective radially outer regions of the inner ring (9) and extending axially outwards therefrom, the ends of said webs or tenons (14a, 14b) being normally retained in the peripheries of two annular troughs (16a, 16b) that are axially spaced apart and constrained to rotate with the shaft (2), the radially inside face (12) of the inner ring (9) being radially spaced apart from the shaft (2) so as to leave the shaft (2) with clearance in the event of said webs or tenons (14a, 14b) breaking, and by the fact that the means for recentering the axis (11) of the shaft (2) on the longitudinal axis X of said turbojet comprise two sets of balls (28a, 28b) each disposed between an axial face (24a, 24b) of the inner ring (9) and the adjacent trough (16a, 16b), each ball normally bearing against the bottoms of two facing indentations, one indentation (25) in the adjacent trough (16a, 16b) and the other indentation (26) in the adjacent front face (24a, 24b) of the inner ring (9), and resilient means (20) urging said trough (16a, 16b) towards each other in order to return the balls (28a, 28b) towards the bottoms of said indentations (25, 26).