Surface Durability

Materials Matter : Roughness Measurement: Optical vs. Contact Stylus Profilometry

Posted by on Sunday, April 19th, 2020 in

Optical profilometry will become an important tool for predicting gear performance with more research and development of an objective lens to fit into tooth spaces....

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Report of the Condition of a General Electric Transportation Systems Gearbox

Posted by on Tuesday, April 14th, 2020 in

Wind power plant operation and maintenance (O&M) costs remain an appreciable contributor to the overall cost of wind energy, with a capacity-weighted average of $11/megawatt-hour (MWh) for projects installed since 2000 and $9/MWh for projects install...

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Materials Matter : Roughness Measurement Tips: Calibration, the Razor Blade Test

Posted by on Tuesday, February 25th, 2020 in

If a problem is found with a contact stylus profilometer during routine check with a Rubert-Song specimen, do a little troubleshooting before sending it off for calibration and recertification....

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A Comparison of Surface Roughness Measurement Methods for Gear Tooth Working Surfaces

Posted by on Friday, October 25th, 2019 in

Surface roughness is a critical parameter for gears operating under a variety of conditions. It directly influences friction and contact temperature, and therefore has an impact on various failure modes such as macropitting, micropitting and scuffing...

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Selecting media for optimum vibe bowl gear finishing

Posted by on Tuesday, August 20th, 2019 in

Choosing the best media depends on structure and shape of the tooth flank, and whether media components should be abrasive, non-abrasive, or a blend....

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Materials Matter: How to Set Up a Vibratory Bowl for Gear Finishing

Posted by on Friday, July 19th, 2019 in

The vibratory bowl is toroidal-shaped, consisting of a center hub surrounded by an OD wall. Direct drive machines have a motor and driveshaft set inside the center hub....

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Physical Characteristics of the Vibratory Bowl and How They Affect Processing Efficiency

Posted by on Friday, July 19th, 2019 in

Vibratory bowls are outfitted with hot-poured polyurethane liners and their durometer hardness is an oft-cited characteristic. But what is durometer hardness and how is it useful?...

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Measuring Tooth Flank Roughness

Posted by on Wednesday, January 23rd, 2019 in

Gear performance has continuously increased over the past two decades. Improvements in metals, heat treatments, geometry, and lubrication are just a few of the sources of these improvements....

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Future Advanced Rotorcraft Drive System (FARDS) Full Scale Gearbox Demonstration

Posted by on Tuesday, June 6th, 2017 in

The Future Advanced Rotorcraft Drive System (FARDS) program focused on improving the performance and affordability of current aircraft drive systems....

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Oil-Out Endurance Under the Lens

Posted by on Friday, March 31st, 2017 in

Oil-out conditions, or conditions in which an aircraft is operating without any oil in its gearbox or transmission, are devastating for an aircraft's hardware....

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Materials Matter: Lambda Ratio

Posted by on Friday, October 21st, 2016 in

The lambda ratio was originally developed to quantify the quality of lubricant operating regimes relative to bearing performance....

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Materials Matter: Micropitting

Posted by on Saturday, September 17th, 2016 in

Micropitting is a gear failure mode that typically occurs when higher contact stresses are applied to hardened gear teeth. Unlike most other failure modes, micropitting does not always proceed to component failure if left unaddressed....

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