BEARING DAMAGE DUE TO ELECTRIC DISCHARGE（由于放电轴承损坏）.pdfVIP

BEARING DAMAGE DUE TO ELECTRIC DISCHARGE ELECTRICAL DISCHARGE MACHINING OF BEARINGS Hugh Boyanton Shaft Grounding Systems, Inc Albany, OR Abstract The frosted, fluted or corrugated pattern often found on the surface of the inner or outer race of an anti-friction bearing is often the result of electrical damage. This type of damage reduces the life of bearings that should last from 6 to 10 years to as little as 4 months. It is estimated that millions of dollars are lost to this class of bearing damage which is wide spread in the HVAC industry and manufacturing industries such as mining, pulp and paper, metals, plastics and food processing. The search leading to the discovery of a major class of bearing damage will be discussed along with a number of factors that mask the underlying causes of this problem. Bearing frosting and fluting problems have been recognized Examples of bearing fluting are shown in figures 1 through 5 below. Note that the flutes can have a very regular machined appearance. In the case of the roller bearing race shown the fluting is very narrow and closely spaced. The fluting pattern is often seen in association with continuous manufacturing processes that are operated at one speed for several hours at a time. Where running speeds vary widely with no predominant speed frosting may be seen instead of fluting. Frosting is an even wear pattern as compared to fluting. ©1995 DPA Sales\H. Boyanton Page 1 of 11 A literature search indicated no previous solution to this fluting problem. A number of theories were presented but the research was not effective in isolating a clear cause and the cost to industry. We can now better define a new class of electrical bearing damage A separate class of bearing failure due to elect