We use cookies to provide you with a better experience. By continuing to browse the site you are agreeing to our use of cookies in accordance with our Privacy Policy.
End users and OEMs frequently specify
"lubed-for-life" mounted bearings, thinking the lubed-for-life bearings will deliver the same life — without lubrication — as bearings that
currently require periodic lubrication. The truth is it depends on many factors, and only a detailed review of the application and testing will provide a more accurate answer.
In this century’s complex, ever-
changing world of manufacturing,
such capabilities as hardware and software expertise, effective location and distribution, business savvy and
yes, even luck, are some of the
cardinal requirements for running
a successful business.
In 1991, Needelman and Zaretsky presented a set of empirically
derived equations for bearing fatigue life (adjustment) factors (LFs) as a function of oil filter ratings.
Engineers typically learn that the bearing L10 life can be estimated using the so called “C/P method” — or the “basic rating life” of
the bearing, a method rooted in the 1940s. Major developments have since led to the “modified rating life,” released in ISO 281:2007,
which includes the aiso life modification factor. In this paper a succession of equations used for bearing life ratings are reviewed, and
current bearing life rating practices are discussed in detail. It is shown that — despite the introduction more than 30 years ago of
the adjustment factor of the basic rating life, and the standardization in 2007 of the aiso modification factor — use of these improved
calculation methods are not practiced by all engineers. Indeed — many continue referring to the old model as a way of seeking
compliance with existing, established practices.
Columnist Brian Langenberg provides a current outlook update, key findings
from a recent energy sector conference, and takes another look at education and employment.
The 8th International CTI Symposium on Automotive Transmissions, HEV and EV Drives took place in Rochester, Michigan from May 12-15. The event kicked off with its popular introductory seminar "Basics and Practice of Automotive Transmissions."