Wear Failure Analysis of Squeezing Sleeves

Spiral seed squeezing machines are commonly used in our country to produce vegetable oil.The spiral squeezing sleeves slipped onto the axis are the main parts doing the work of squeezing the seeds.The wear life of them shall be very important to the effective service of the machine The wear failure analysis of these sleeves was done in this paper.The squeezing chamber in the machine can be divided into 3 zones, namely, "feeding zone", "presqueezing zone" and "squeezing zone".Because the squeezing pressure in the last zone is high and the seeds become highly compacted "non-compressible bodies" the sleeves in that zone are sustaining high stress grinding wear and wears fast This is proved by the wear morphology of these sleeves.Wear failure analysis is mainly done on them.The SEM examinations of the wear face and section through the subsurface show that the wear mechanisms of the sleeves are; deformation wear mechanism,cutting wear mechanism, tearing wear mechanism and fatigue wear mechanism by non-compressible bodies and high pressure erosive wear mechanism by liquid oil produced. The main causes of failure are the former two mechanisms.Alloy white cast iron con taining carbide of high hardness and having high macro-hardness was suggested to make those sleeves to replace carburized steel and proved to be much more cost effective.