Failure Analysis of Outer Ring Fracture of Floating Bearing

Abstract

The main drive growth box of high speed wire finishing mill adopts the structure of cylindrical roller bearing and deep groove ball bearing as the support of gear shaft. Because the outer ring of the ball bearing is not radial constrained，running in a floating state（floating bearing）. The growth box is used for less than one year and the outer ring of the ball bearing is broken. After field investigation，optical microscope and electron microscope observation，bearing material composition and metallographic structure analysis，and bearing outer ring finite element simulation，it can be confirmed that the direct reason for the fracture of floating bearing outer ring is that the stress of floating outer ring is about 33.3% larger than that of fixed outer ring，which results in the excessive stress of the outer ring. Secondly，serious spalling and electric erosion damage occur in the bearing raceway，which causes great stress concentration in the raceway and causes the fracture of the outer ring. Aiming at above problem，the improvement measures are put forward

Keywords

• Failure analysis
• Growth box
• Rolling bearing
• Outer ring fracture