Hur kan vi styra ytfinheten?

Abstract

Grinding technique is one of the oldest manufacture techniques used and is a determining factor for reducing the last material on a product that will be processed to go from a rough surface to a smooth surface. During the grinding process the problem of surface roughness arises as it is hard to control. The surface roughness and what is affecting it has been examined for decades to understand essential issues such as contact deformation and heat that emerges at Ra-values outside of the desired tolerances. Research has concluded that there are many parameters that affect the surface roughness during grinding, such as cooling and vibrations. Despite the existing knowledge in the field several companies have issues trying to control the surface roughness. SKF AB Sweden in Gothenburg strives to control the surface roughness while having constraints on dimensions, surface profile and making sure that the characteristics confirm with the given specifications. This thesis conducted at SKF examines how the above-mentioned parameters affect the surface roughness. Initial interviews and expert consultations led to a series of test to uncover the relationship with the surface roughness (Ra). It is shown that the influence on the Ra-value is complex and could not be controlled by the given parameters. The project is limited to tests conducted at SKF's E factory on the outer ring inner spherical inner surface on a selected series of bearing. The results of the project have extended the knowledge base within the field and put us one step closer to being able to control the surface roughness of sphere rings.