REM Surface Engineering

Rotorcraft Gearbox Regulations: LOL (not what you think)

Posted by on Monday, March 16th, 2020 in

The European Union’s CS-29 Amendment 7 places more stringent and rigorous testing requirements for certification of Category A type pressurized gearboxes under loss of lubrication conditions compared to the previous regulation....

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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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Roughness Measurement Tips: The Scratch Pad

Posted by on Thursday, January 16th, 2020 in

From the perspective of the shop floor environment, the previous Materials Matter column “Roughness Measurement Tips: 2 V 5” discussed the contact stylus 2-micron radius tip versus a 5-micron radius tip....

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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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Surface Treatment of Powder-Bed Fusion Additive Manufactured Metals for Improved Fatigue Life

Posted by on Friday, January 11th, 2019 in

High-cycle fatigue (HCF) tests were conducted on samples fabricated by two powder-bed additive manufacturing techniques....

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Materials Matter : Surface Finishing Rotorcraft Gearing

Posted by on Wednesday, October 3rd, 2018 in

Rotorcraft gearboxes are designed with the utmost precision to withstand the tremendous demand and loads required to convert thousands of horsepower and RPM into hundreds of RPM and lift torque....

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AH-64 Loss of Lubrication Study: Test of Isotropic Superfinished AH-64 (Apache) Engine Nose Gearbox Without Black Oxide Coating

Posted by on Wednesday, September 19th, 2018 in

Rotorcraft gearboxes are designed to the utmost precision to withstand the tremendous demand and loads required to convert thousands of horsepower and RPM into hundreds of RPM and lift torque....

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Materials Matter : The State of the Art of Wind Turbine Gearboxes

Posted by on Wednesday, September 5th, 2018 in

Much has been written here about the global growth in the wind turbine industry. Today, more than 341,320 wind turbines are operating worldwide. In particular, the number of offshore installations has exploded in the past seven years....

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