September/October 2016

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Feature Articles

Managing Shop Floor Data
There's no substitute for a good software package in gear manufacturing. It's a critical shop floor tool that provides practical engineering services that customers appreciate. When you're in the business of specifying and procuring high quality gears, the software needs to meet many objectives including the consideration of all tolerances of center distance, tooth thickness and tip diameters, root diameters, fillets, etc. It's also imperative that the software updates include the latest revisions to the gear standards being used in the industry.

Innovating Against the Tide
During a year with a strong dollar, tanked oil prices and a number of soft markets that just aren't buying, one might expect spline manufacturers to be experiencing the same tumult everyone else is. But when I got a chance to speak with some of the suppliers to spline manufacturers at IMTS about how business is going, many of the manufacturing industry's recent woes never came up, and instead were replaced by a shrug and an "eh, business is doing pretty well."

AGMAs Go-To Gear Guys
While the two have taught a variety of AGMA courses over the years, without question their most popular courses are Gear Failure Analysis (Errichello with longtime colleague Jane Muller) and Gearbox CSI: Forensic Analysis of Gear & Bearing Failures (Drago). Drago currently teaches Manufacturing & Inspection (with AGMA instructor Joseph W. Lenski, Jr.) and Gearbox System Design: The Rest of the Story - Everything but the Gears and Bearings (with AGMA instructor Steve Cymbala) as well.

Technical Articles

Increased Tooth Bending Strength and Pitting Load Capacity of Fine-Module Gears
The common calculation methods according to DIN 3990 and ISO 6336 are based on a comparison of occurring stress and allowable stress. The influence of gear size on the load-carrying capacity is considered with the size factors YX (tooth root bending) and ZX (pitting), but there are further influences, which should be considered. In the following, major influences of gear size on the load factors as well as on the permissible tooth root bending and contact stress will be discussed.

A Proposed Pre-Finish Cylindrical Gear Quality Standard
This proposed standard would not make any recommendations regarding the required quality for any application. The intent is to establish standard pre-finish quality classes for typical finishing operations, which only include the inspection elements that are important to properly evaluate pre-finish gear quality as it applies to the finishing operation. It would be the responsibility of the manufacturing/process engineer, quality engineer, or other responsible individual to establish the required pre-finish quality class for their application.

Finite Element Analysis of Tooth Flank Fracture Using Boundary Conditions from LTCA
This paper demonstrates an application of the tooth interior fatigue fracture (TIFF) analysis method, as implemented in SMT's MASTA software, in which loaded tooth contact analysis (LTCA) results from a specialized 3-D contact model have been utilized to determine the load boundary conditions for analysis of tooth flank fracture (TFF).

Departments

IMTS Cuts the Mustard (Publishers Page)
IMTS, held bi-annually here in Chicago, ended September 17. It was the third-largest IMTS ever, both in terms of registrations (115,612) and exhibit space occupied (1,370,256 square feet). Also, this year's show had more exhibiting companies (2,407) than any previous IMTS.

Product News (Product News)
News on the latest products in the industry.

Same Hob for Two Gears (Ask the Expert)
I make all the double helical gears that go into a gearbox - four different gears in this unit. If the gear module for the bull gear and the intermediate gear are the same (these are the two individual gears that mate), and the gear module for the high-speed pinion and high-speed gears are the same (these are the other two individual gears that mate in the gear box as well), is it then possible to just use two hobs in this setup to make all four gears, since they mate together with each other? We are currently using a different gear hob for each gear.

Calendar (Events)
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Industry News (Industry News)
News From Around the Gear Industry

Most Famous Gear in Motown (Addendum)
It's hard for me to think of a massive Christmas exhibit as being the fifth largest tourist attraction in the entire country. I mean, sure, it's still a tradition to show up at the local Macy's to check out the Christmas decorations, but for my generation, the idea that a Christmas exhibit could draw out 1.5 million visitors, more tourists than either Yellowstone Park or the Statue of Liberty received, is stunning. But at the height of its popularity, that's exactly what the Ford Rotunda was.