Overhung Fans with spherical Roller Bearings
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Fixed & Floating Bearings on Overhung Fans - A Critical Reliability Issue for Sherical Roller Bearings that are subject to Significant Axial Force
A month or so ago I visited some of the Reliability people from Shell at Clyde Refinery. They had been very pleased to receive the Skills and Practices Flyers in our last Newsletter. It help them understand a problem they were having with overhung impeller fans. This reinforced to me the importance of this specific reliability issue of axial force applied to spherical roller bearings. This article brings together the information provided on this issue by Rod Bennett.
Which of the spherical roller bearings on the fan shaft below should be fixed and which should be floating?
The Answer to the question -Media:-43_OH_Fan_Brgs_Part_1.pdf
More information about the cause of the problem -Media:-44_OH_Fan_Brgs_Part_2.pdf
This case study report gives more background to the issue and how Rod was able to solve this problem in his plant Media:SRB_SIRF_National_CM_Forum.PDF. It is a case history on condition monitoring, root cause analysis and design Overhung fans are often mounted on spherical roller bearings in plummer blocks. This arrangement is seen as being low cost and facilitating easy bearing replacement. However, depending on the arrangement of the drive, and the location of the fixed bearing, this arrangement can create chronic reliability issues. A case history is presented, along with the process for understanding root cause and a solution to the problem.
