A computational fluid dynamics (CFD) method is adapted, validated and applied to spinning gear systems with emphasis on predicting windage losses.
Several spur gears and a disc are studied. The CFD simulations return good agreement with measured windage power loss.
Two high-volume gear production cells grace the shop floor at Delta Research Corporation in Livonia, Michigan. Thanks to lean manufacturing, these cells have never shipped a defective part to a customer since they were developed over three years ago.
As is well known in involute gearing, “perfect” involute gears never work perfectly in the real world.
Flank modifications are often made to overcome the influences of errors coming from manufacturing and assembly processes as well as deflections of the system. The same discipline applies to hypoid gears.
Many engineers and purchasing agents think it is more expensive to custom design a component or assembly these
days when often customization can save on total costs.
It may not be widely recognized that most of the inspection data supplied by inspection equipment, following the
practices of AGMA Standard 2015 and similar standards, are not of elemental accuracy deviations but of some form of composite deviations. This paper demonstrates the validity of this “composite” label by first defining the nature of a true
elemental deviation and then, by referring to earlier literature, demonstrating how the common inspection practices for involute, lead (on helical gears), pitch, and, in some cases, total accumulated pitch, constitute composite measurements.
Traditionally, gear rating procedures consider manufacturing accuracy in the application of the dynamic factor, but
only indirectly through the load distribution are such errors in the calculation of stresses used in the durability and gear strength equations. This paper discusses how accuracy affects the calculation of stresses and then uses both statistical
design of experiments and Monte Carlo simulation techniques to quantify the effects of different manufacturing and
assembly errors on root and contact stresses.
The auction has been held. The warehouse is bare. The computers
and furniture are being packed, and Cadillac Machinery, the company
started by my father in 1950, and of which I was president for more
than 25 years, is close to being no more.
If a gear system is run continuously for long periods of time—or if the starting loads are very low and within the normal operating spectrum—the effect of the start-up conditions may often be insignificant in the determination of the life of the gear system. Conversely, if the starting load is significantly higher than any of the normal operating conditions,
and the gear system is started and stopped frequently, the start-up load may, depending on its magnitude and frequency, actually be the overriding, limiting design condition.