January/February 2016

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Feature Articles

Looming Large
Let's talk about large gears. Not the size or scope or inspection process, but the forecast and market potential in areas that utilize these massive components. We'll examine key industry segments like energy and mining and tap IHS Economics for a forecast for 2016 and 2017 (spoiler alert: it's not great). Additionally, we'll discuss some of the critical factors influencing global big gear manufacturers Ferry-Capitain and Hofmann Engineering.

Technical Articles

Thermal Behavior of a High-Speed Gear Unit
In this paper a thermal network model is developed to simulate the thermal behavior of a high-speed, one-stage gear unit which is jet-lubricated.

Influences on Failure Modes and Load-Carrying Capacity of Grease-Lubricated Gears
In order to properly select a grease for a particular application, a sound knowledge of the influence of different grease components and operating conditions on the lubrication supply mechanism and on different failure modes is of great benefit.

The Importance of Profile Shift, Root Angle Correction and Cutter Head Tilt
Chapter 2, Continued In the previous sections, development of conjugate, face milled as well as face hobbed bevel gearsets - including the application of profile and length crowning - was demonstrated. It was mentioned during that demonstration that in order to optimize the common surface area, where pinion and gear flanks have meshing contact (common flank working area), a profile shift must be introduced. This concluding section of chapter 2 explains the principle of profile shift; i.e. - how it is applied to bevel and hypoid gears and then expands on profile side shift, and the frequently used root angle correction which - from its gear theoretical understanding - is a variable profile shift that changes the shift factor along the face width. The end of this section elaborates on five different possibilities to tilt the face cutter head relative to the generating gear, in order to achieve interesting effects on the bevel gear flank form. This installment concludes chapter 2 of the Bevel Gear Technology book that lays the foundation of the following chapters, some of which also will be covered in this series.

Departments

Smart Ideas for 2016 (Publishers Page)
For us, 2016 is the year of smart ideas. Not our smart ideas, but yours. We've spent a lot of effort collecting information from Gear Expo, our State of the Gear Industry annual survey and market research to find out more about what you want from us. We've also taken your suggestions and used them to make improvements, add new features and build on what we've been doing here for 32 years in our role as the Gear Industry's Information Source.

Product News (Product News)
Latest news about the Latest Products

Premature Gear Failure (Ask the Expert)
I would appreciate if you could assist with a gear failure (occurring) after just seven weeks in service, post installation. This driving gear wheel has been installed in a medium-speed engine with backlash present at four different positions; with additional backlash checked on the mating surfaces. All backlash was found within (OEM)-recommended values. Please note included photos - it seems that the crack has started at the root fillet. Any comments would be appreciated.

Calendar (Events)
Calendar of Events

Industry News (Industry News)
Latest new from the Gear Industry

Mind-Boggling Gears (Addendum)
Square, rectangular, triangular, oval, even fish-shaped - Clayton Boyer's Weird Gears come in every shape except for circular, and they all work. If you're interested in giving them a gander, check out Boyer's Youtube video (just search "weird gears" and it'll be right there at the top) to see them in motion