New Conductive Grease by Nye Lubricants Shields Bearings from Arcing Damage
FAIRHAVEN, Mass.--Oct. 17, 2002--With its introduction of Nyogel 758G, Nye Lubricants, Inc. takes a simple but novel approach to designing an electrically conductive bearing grease: Start with a good grease.
The traditional approach to making electrically conductive grease is to mix copper, silver or carbon particles with oil. These paste-like materials are conductive, but they are not very good bearing greases. Metals are not ideal thickening systems for bearing greases. They are not lubricious and they are too loose to "channel," i.e., move to the side to create an oily path on which the rolling element can spin around the race. Further, the conductivity of metal-thickened formulations is often short-lived. Under shear, the matrix of conductive particles can break down, degrading the electron pathway, again subjecting the rolling elements and the raceway to electrical damage.
Nye's Nyogel 758G starts as a lubricious, channeling bearing grease. It is a blend of synthetic ester oils, which have a strong affinity to metals, and lithium soap, known for its excellent channeling abilities. Instead of relying on metal, carbon, or organic conductive additives to achieve conductivity, Nyogel 758G incorporates a proprietary combination of standard lubricant additives that not only fortify the oil and protect it from oxidation, but also work synergistically to create an electron pathway through the grease. This phenomenon is explained in "Capturing the Synergistic Effect of Additives To Formulate a Long-Life, Electrically Conductive Bearing Grease," a technical paper co-authored by Michael J. Dube, Nicole St. Pierre, and Jay Weikel. Weikel presented the paper at the Appliance Design and Technology Expo in Cincinnati in October.
Weikel reported that even though Nyogel 758G contains only a very small percentage of carbon particulate, "it has a volume resistivity of 300 ohm-cm (Test Method: CTM-12), which is comparable to or lower than electrically conductive greases that rely exclusively on conductive thickeners and conductive additives for their conductivity."
Electrostatic discharge from motor shafts or other nearby sources is known to reduce the life of shaft-support bearings from years to a matter of months. It is estimated that millions of dollars are lost to this type of bearing damage. Electrically conductive bearings greases like Nyogel 758G may help reduce or prevent such damage.
To request more information about Nyogel 758G or to receive an electronic copy of the technical paper, please send an e-mail to techhelp@nyelubricants.com or call Nye at 508-996-6721.
Nye Lubricants is an engineering company dedicated to formulating high quality synthetic lubricants that add measurable value to customers' components. Its products are specified in a full range of industries, including automotive, aerospace, appliance, aviation, electronics, medical instrumentation, office automation, paperboard manufacturing, photonics, recreational equipment, semiconductor manufacturing, telecommunications, and textiles. Founded in 1844, Nye maintains regional engineering offices throughout the United States as well as a network of distributors in Africa, Asia, Australia, Europe, and South America.