Towards an Improved AGMA Accuracy Classification System on Double-Flank Composite Measurements

In 2001 AGMA introduced the first of two documents: ANSI/AGMA 2015–1–A01: Accuracy Classification System—Tangential Measurements for Cylindrical Gears, followed in 2006 by the release of ANSI/AGMA 2015–2– A06: Accuracy Classification System—Radial System for Cylindrical Gears. Both of these documents, when combined, officially replace the still widely used standard, AGMA 2000–A88: Gear Classification and Inspection Handbook. Although ANSI/AGMA 2015–2–A06 was adopted by the general membership, it is likely that most members—even to this day—do not fully understand how this document differs from AGMA 2000–A88 in its application to the double-flank measurement of a gear. In the author’s viewpoint, some of the improvements that ANSI/AGMA 2015–2–A06 was intended to provide, in fact resulted in just the opposite; i.e., more uncertainty in terms of product quality than what existed previously. It is recommended that ANSI/AGMA 2015–2–A06 be revised to reflect the concerns expressed in this document. Concerns with ANSI/AGMA 2015–2–A06 and How to Resolve Them Removal of the long-term component in the calculation of tooth-to-tooth deviations. ANSI/AGMA 2015–2–A06 in its definition of the tooth-to-tooth radial composite deviation, fid, recommends that “The long-term component sinusoidal effect of eccentricity should be removed from the waveform before determining the tooth-to-tooth deviation value,” whereas the AGMA 2000–A88 document relies on raw data. This long-term component, its definition and its implications are the crux of the concerns relating to ANSI/AGMA 2015–2–A06. AGMA used techniques from single-flank testing in relation to data filtering and long-form component removal and applied it to double-flank testing on the assumption that its use would be a better predictor of noise quality. This correlation between tooth-to-tooth radial composite deviation measured in this manner and noise has never been proven; rather, as will be demonstrated here, it will (Printed with permission of the copyright holder, the American Gear Manufacturers Association, 1001 N. Fairfax Street, Fifth Floor, Alexandria, VA 22314-1587. Statements presented in this paper are those of the author(s) and may not represent the position or opinion of the American Gear Manufacturers Association.) Towards an Improved AGMA Accuracy Classification System on Double-Flank Composite Measurements