his own gear consulting firm,
GEARTECH, and is founder
of GEARTECH Software,
Inc. He has over 50 years of
industrial experience. He has
been a consultant to the gear
industry for the past 37 years
and to over 50 wind turbine manufacturers,
purchasers, operators, and researchers.
He has taught courses in material science,
fracture mechanics, vibration, and machine
design at San Francisco State University and
the University of California at Berkeley. He
has presented numerous seminars on design,
analysis, lubrication, and failure analysis of
gears and bearings to professional societies,
technical schools, and the gear, bearing,
and lubrication industries. A graduate of the
University of California at Berkeley, Errichello
holds BS and MS degrees in mechanical
engineering and a Master of Engineering
degree in structural dynamics. He is a member
of several AGMA Committees, including the
AGMA Gear Rating Committee, AGMA/AWEA
Wind Turbine Committee, ASM International,
ASME Power Transmission and Gearing
Committee, STLE, NREL GRC, and the Montana
Society of Engineers. Bob has published over
80 articles on design, analysis, and application
of gears, and is the author of three widely used
computer programs for design and analysis
of gears. He is technical editor for GEAR
TECHNOLOGY and STLE Tribology Transactions.
Errichello is recipient of the AGMA TDEC
Award, the AGMA E.P. Connell Award, the
AGMA Lifetime Achievement Award, the STLE
Wilbur Deutch Memorial Award, the 2015
STLE Edmond E. Bisson Award, and the AWEA
Technical Achievement Award.
The objective of this paper is to improve the methodology for determining the tooth flank temperature. Two methods are proposed for assessing scuffing risk when applying AGMA 925 for high-speed gears. Both methods provide similar results.
I felt a tap on my shoulder. Turning, I saw the chief draftsman who said, "You're in charge of gears." And he walked away. Dumbfounded, I stared at the back of his head, and sat down at my drafting board. It was November, 1963, shortly after JFK was assassinated, and after I was discharged from the U.S. Army.
The purpose of this article is to provide an overview of proven books or
standards dealing with failure analysis. Following you will find a short description of ten books or standards. At the end of the document you will find an overview and a detailed reference list.
There exists an ongoing, urgent need for a rating method to assess micropitting risk, as AGMA considers it a "a very significant failure mode for rolling element bearings and gear teeth - especially in gearbox applications such as wind turbines."
This review of elastohydrodynamic lubrication
(EHL) was derived from many
excellent sources (Refs. 1–5). The review of Blok’s flash temperature theory was derived from his publications (Refs. 6–9). An excellent general reference on all aspects of tribology is the Encyclopedia of Tribology (Ref. 10).
I have heard that X-ray diffraction does not tell the whole story and that I should really run a fatigue test. I understand this may be the best way, but is there another method that gives a high degree of confidence in the residual stress measurement?
I must confess I sometimes find myself a bit dazed when discussing lubrication issues with either staff or vendors. The terminology seems to be all over the lot, with some terms having double meanings. Can you help cut through the confusion?
For maximum life in carburized and ground gearing, I have been advised that fully grinding a radius into the root gives maximum resistance against fatigue failures. Others have advised that a hobbed and unground radius root form is best. Which is best, and why?