CONCEPT OF USING TEFLON LINED BOLTS/SCREWS FOR BLADE FOLDING ON NAVAL HELICOPTERS

摘要

ABSTRACT During Manual blade folding or automatic blade folding, certain number of linkages has to be dis-engaged in the main rotor head of a helicopter. During this disengagement, some bolts/screws have to be removed to fold main rotor blades about its own main bolt axis and has to be inserted back to its original location during unfolding. On repeated operations of folding and unfolding, Teflon liner on the ID of the bush is getting damaged. In this case of damage to the Teflon liner, the bush need to be replaced which calls for removal of Main Rotor Blade from helicopter resulting in high downtime. To facilitate quick repair of damaged Teflon liner and continued flying from ship deck, design was modified to have the Teflon liner on the Bolt OD / Screw OD instead of bush ID. In case of Teflon liner on the Bolt / Screw gets damaged, this can be replaced by a spare Bolt / Screw which helps to complete the blade folding satisfactorily without disturbing the main rotor blade which helps in continued flying from ship deck.