Failure Modes of Spontaneous Damage of Wet-Running Multi-Plate Clutches with Carbon Friction Linings

Abstract

Carbon friction linings are increasingly being used for clutches in industrial applications on account of their excellent properties in terms of friction behavior, temperature resistance and wear (1). Due to safety-relevant use of these clutches, their failure must be avoided and thus the damage behavior must be investigated. In this paper, the spontaneous damage behavior of two multi-plate clutches (FS-1, FS-2) with different carbon friction linings (a woven and a composite carbon friction one) is investigated experimentally. For this purpose, the mechanical load was increased step-by-step in step tests with brake shifting and the damage progression was documented by regular dismounting of the clutch. For the FS-1 friction system with composite carbon friction lining, the initial damage was local discoloration of the steel plates due to oil cracking products. The failure of the system occurs in friction system 1 due to shrinkage of the steel plates on the inner carrier. For the FS-2 friction system with woven carbon friction lining, the initial damage is also discoloration of the steel plate. With increasing load there is a displacement of the friction lining pads. The failure of the system is caused by the detachment of the friction lining from the carrier plate. The research results highlight the potential for improvement of the multi-plate clutch in terms of a more temperature-resistant adhesive layer between the carrier plate and the friction lining. In addition, the steel plates must be heated evenly in the radial direction, which can be achieved by optimizing the geometry.