Micropitting - Articles | Gear Technology Magazine

Results of ISO/TS 6336-22 Evaluating Full Contact Zone

June 20, 2023

Robin Olson, Mark Michaud, Jon Keller, and John B. Amendola

This investigation reviews calculations using ISO/TS 6336-22 Method A and Method B, comparing the calculations against field results. Extensive reviews were made of geometry, surface roughness, load conditions, and lubricant conditions to best understand the influences of micropitting on each example and the applicability of the calculations to the results.

Nomenclature of Micropitting

August 30, 2022

Robert Errichello

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An overview of the incubation, nucleation and growth, and morphology of this common failure mode, along with the appropriate terminology to describe it.

Image used on web version of announcement.jpg

Two New AGMA Publications

May 19, 2022

Phillip Olson

AGMA is happy to announce the publication of two new documents: AGMA 925-B22, Effect of Tribology and Lubrication on Gear Surface Distress, written by a subcommittee of the AGMA Helical Gear Rating Committee, and, AGMA 943-A22, Tolerances for Spur and Helical Racks, written by the AGMA Gear Accuracy Committee.

Case Study of ISO/TS 6336-22 Micropitting Calculation

March 1, 2021

Micropitting per ISO standard explained.

That Blank Sheet of Paper

October 10, 2019

Charles D. Schultz

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Does nature hate a vacuum more than a designer hates a blank sheet of paper? We will never know for sure because nature is too busy to write a blog...

Moderation Instead of Modification

April 12, 2018

Charles D. Schultz

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Few designers would feel comfortable with a face to pinion pitch diameter ratio of 2.00 anymore. Some still prefer to select face width by face con...

Critique of the ISO 15144-1 Method to Predict the Risk of Micropitting

March 1, 2016

Robert Errichello

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."

Optimal Modifications on Helical Gears for Good Load Distribution and Minimal Wear

June 1, 2015

Helical gear teeth are affected by cratering wear — particularly in the regions of low oil film thicknesses, high flank pressures and high sliding speeds. The greatest wear occurs on the pinion — in the area of negative specific sliding. Here the tooth tip radius of the driven gear makes contact with the flank of the driving gear with maximum sliding speed and pressure.

Micropitting of Large Gearboxes: Influence of Geometry and Operating Conditions

September 1, 2014

The focus of the following presentation is two-fold: 1) on tests of new geometric variants; and 2) on to-date, non-investigated operating (environmental) conditions. By variation of non-investigated eometric parameters and operation conditions the understanding of micropitting formation is improved. Thereby it is essential to ensure existent calculation methods and match them to results of the comparison between large gearbox tests and standard gearbox test runs to allow a safe forecast of wear due to micropitting in the future.

Morphology of Micropitting

November 1, 2012

Robert Errichello

Understanding the morphology of micropitting is critical in determining the root cause of failure. Examples of micropitting in gears and rolling-element bearings are presented to illustrate morphological variations that can occur in practice.