The approach developed in this research aims to aid a further understanding of the correlations between the energy generated during material removal and the power signals from the machine control during generating gear grinding.

Overall developments and widespread public awareness of man-made climate change are transforming the way people think. The awareness has inspired a shift towards a more ecologically sustainable way of life. Driven by policymaking and technological innovation, ambitious efforts are underway to reduce greenhouse gas emissions to curb the rise in average temperatures. A key focus of these efforts is the mobility sector. 

If you are a true gear geek, you are probably aware of AGMA’s Fall Technical Meeting (FTM). However, we have true gear geeks attending the FTM for the first time each year, and we are thrilled to see that!

This report uses an application case to demonstrate the optimization potential of gear skiving in the production of internal splines on a universal machining center. The process established in the example is then analyzed using the software tool OpenSkiving developed by the wbk Institute of Production Science of the Karlsruhe Institute of Technology (KIT) and the results are discussed. Finally, the most important findings are summarized.

For cylindrical gears, speed-increasing transmission stages are well known, and regarding profile shift, preferred pressure angles, and helix angles a set of rules applies, which is not much different from the rules for speed reducers. It is important to acknowledge that basically, a speed increaser has to be designed just like a speed reducer, but then the gear with the lower number of teeth is the output. Of course, the torque and the speed of the gear with the lower number of teeth (output) and the gear with the higher number of teeth (input) must be the same as if this transmission was used as a speed reducer. In the case of straight bevel gears, spiral bevel gears, and hypoid gears the same rules apply with some additions. Spiral bevel gears have many applications as speed increasers.  

This paper presents a comparison of the linear and nonlinear approaches for damage accumulation of tooth root breakage damage of gears. In the beginning, the theoretical fundamentals of damage accumulation are presented compactly. To compare the suitability of the methods an extensive set of experimental data is presented at first. The data is evaluated with both the linear and the nonlinear approach and the results are compared. For the linear approach, the method according to Miner and Palmgren is applied. For the nonlinear approach, the method developed by Subramanyan is used. The objective of this evaluation is to assess if the more complex method yields a potential benefit for a more accurate service life prediction of gears.

An extremely wide selection of different plastic materials is currently available on the market. A major limitation, however, is a huge gap in gear-specific material data on these materials, which is a problem that has been persisting for decades now. Providing a step towards a solution is the German guideline VDI 2736, which proposes design rating methods (Ref. 2) along with testing procedures (Ref. 3) to be followed to generate reliable data required in the gear rating process. This paper delves into the current state of the art in plastic gear testing, providing a comprehensive overview of employed testing methods, supplemented with case studies.

For wind turbine main gearboxes (MGBs) with about 1 MW or higher power, gearbox designs with multiple power paths are used. They handle several mega-Newton-meter of torque economically. Earlier wind turbines with lower power ratings used parallel shaft gearboxes with only one power path but soon they were superseded by planetary gearboxes having typically three to five planets per stage. This paper describes experiences using planetary gears where “Flexpins” are used to improve the load sharing between the individual planets—representing the multitude of power paths—and along the planet’s face width.

This paper recommends a 2-speed-automatic transmission for passenger cars with power <100 kW and for all trucks.

This paper shows a methodology to extensively evaluate different designs of epicyclic gear systems. As outlined, no choice is required on the part of the designer who is free to probe all design variables.