There's never been a better time to put the spotlight on e-drive transmissions and electric vehicles. They're obviously not just coming: they're already here. Just check out any auto show or
showroom. That's why Gear Technology magazine is pleased to present the first installment in a series of chapters excerpted from Dr. Hermann J. Stadtfeld's newest book, "E-Drive Transmission
Guide - New solutions for electric- and hybrid transmission
vehicles."
This study deals with the modeling and consideration of misalignments in planetary gearboxes in the optimization and design process. Procedures for taking into account misalignments in cylindrical gearboxes are standardized and established in industry. Misalignments of central elements like carrier, sun gear or ring gear in planetary gearboxes, cause varying contact positions and variable loads, depending on the angular position of the central elements. This load, which is variable over the circumference, is not taken into account in the standardized procedures, despite its effects on the loads on the gears.
A meaningful discussion about noise is quite difficult because the impression of "noise" is quite subjective. Everybody has a lifetime experience with sound / noise and sees themselves as an expert.
Due to production by pressing and sintering, PM gears are porous. Since pores reduce the loaded area and are also probable crack initiators, the porosity determines the strength of the PM component. PM gears can be densified to increase their local density and, therefore, the load-carrying capacity. PM gears are compacted locally since they are mainly loaded directly at the surface. A common process to densify PM gears locally is the cold rolling process. The contact conditions in the cold rolling process determine the density profile and, therefore, the material properties of the PM component. The influence of the contact conditions in cold rolling of PM gears on the resulting density profile is yet to be investigated.
In this article, the focus is put on one technology, X-ray diffraction (XRD), and more specifically, residual stress measurement by way of XRD for both process development and quality control.
Mathematically precise tooth surface definition and contact
analysis help to develop state-of-the-art straight bevel gears for
many industrial applications. The new Coniflex-Plus manufacturing
process utilizes high-speed dry cutting with production
times per slot which are about twice compared to the fast
Revacycle process.
Nowadays, the progress in polymer materials and injection molding processing has enabled a drastic expansion of plastic gear applications. They are used not only for lightly loaded motion transmissions, but also in moderately loaded power drives in automotive, agriculture, medical, robotics, and many other industries.
In the wind power industry, the reliability of powertrain components plays a major role. Especially in multi-megawatt offshore applications, an unplanned replacement of drivetrain
components can lead to extremely high costs. Hence, the expectation of wind farm operators is to forecast the system reliability. Under the leadership of the VDMA (Mechanical Engineering Industry Association), the standardization paper 23904 "Reliability Assessment for Wind Turbines" was published in October 2019.