Design and Manufacturing of Clutch in Tunnel Boring Machine

A non-asbestos semi-metallic stainless steel/carbon fiber reinforced PEEK-based friction material was developed and applied in Tunnel Boring Machine(TBM) driven clutch friction plate. The uniform design method of 5 factors and 27 levels was used to design and optimize the match composition. The friction plates were manufactured by dry-processing procedure, comprising mixing, pre-heating, cold pressing, adhesive coating, hot pressing and heat treatment. Friction and wear tests were carried out using a pin-on-disc type high temperature tribo-tester. The developed stainless/carbon fibers reinforced PEEK friction plates were used in Tunnel Boring Machine. The friction and wear mechanism was analyzed through observing the worn surface morphology by scanning electron microscope (SEM). The test results showed that the developed compound has better heat stability and wear resistance with slightly lower hardness and higher compress strength and impact toughness than asbestos composite, and these can decrease the wear of counter discs. The wear mechanism is mainly adhesive wear with lighter abrasive wear. The worn traces of developed friction plate were indistinct and damage degree of the counter plates was little, showing that the developed friction plate is suitable for TBM clutch Disc in hard working conditions of tunnel boring.