In recent years the estimation of gearbox power loss is attracting more interest — especially in the wind turbine and automotive gearbox industry — but also in industrial gearboxes where heat dissipation is a consideration as well. As new transmissions concepts are being researched to meet both ecological and commercial demands, a quick and reliable estimation of overall efficiency becomes inevitable in designing the optimal gearbox.

After a sluggish 2013, annual installations of new wind turbines grew by 44% in 2014, according to the Global Wind Energy Council. And while much of that growth has been in Asia— particularly China, which now leads the world with 114 GW of installed capacity—the USA, Europe, and the rest of the world expect steady growth for the next couple of years as well (Fig. 1).

Previously we discussed how to determine your cup interference fit based on thermal expectations. Then we discussed how the bearing cup contracts a...

Engineers typically learn that the bearing L10 life can be estimated using the so called “C/P method” — or the “basic rating life” of the bearing, a method rooted in the 1940s. Major developments have since led to the “modified rating life,” released in ISO 281:2007, which includes the aiso life modification factor. In this paper a succession of equations used for bearing life ratings are reviewed, and current bearing life rating practices are discussed in detail. It is shown that — despite the introduction more than 30 years ago of the adjustment factor of the basic rating life, and the standardization in 2007 of the aiso modification factor — use of these improved calculation methods are not practiced by all engineers. Indeed — many continue referring to the old model as a way of seeking compliance with existing, established practices.

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The next step in our aluminum housing series is to determine where the cup interference is going. If we press a cup with 100µm interference into a ...

The interference fit that cups should have in an aluminum housing seems to be a subject that comes across my desk in regular intervals. Of course, ...

I recently had a supplier give me a call to let me know that we had some outdated paperwork floating around that was going to wind up costing us a ...

Engineers are often challenged with the seemingly impossible task of doing more with less. Customers want more power transmitted in a smaller space, they want more efficient designs, and, of course, they want to spend less money. So engineers are always looking for ways to squeeze the most out of their mechanical systems. They’re constantly working to maximize power density, increase energy efficiency and reduce costs to meet their customers’ needs.

It seems preposterous in the whimsical, wireless world of today, but in 1977 cinema’s greatest visioneers came together and decided the pinnacle of robotic technology in the future would be a motorized trash can.