Identification of Dominant Factor Deciding Wet Clutch Damage on Forklift Trucks According to Difference of Operating Application

Damaged clutches that were returned from the field typically had 3 types of symptoms: 1.Only the friction material was damaged, 2.Only the mating plates were deformed, 3.Both symptoms were observed together. Root cause identification of these symptoms by relationship with the difference of operating application is the purpose of this paper. Field load frequency of each application was organized and the life time of the friction material and the presence/absence of the mating plate deformation were determined by the original calculations. The result were: 1.On the application that the clutch absorbed the energy during short term, the mating plate deformation was dominant, 2. On the application that the clutch absorbed the energy during long term, the friction material life was dominant.