Machine Design
Elastic nut is a locking device in which

A slot is cut partly in middle of nut and then slot reduced by tightening a screw
One small nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
Through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter pin splitted and bent in reverse direction at other end
Hard fibre or nylon cotter is recessed in the nut and becomes threaded as the nut is stewed on the bolt causing a tight grip

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Machine Design
When the shaft rotates in anticlockwise direction at slow speed in a bearing, it will

Move towards left of the bearing making metal to metal contact
Have contact at the bottom most of the bearing
Move towards right of the bearing making no metal to metal contact
Move towards right of the bearing making the metal to metal contact

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