Emerging technology gets lots of coverage in all forms of media; obsolete technology is still the backbone of our economy. Self-driving vehicles ex...

In this paper local tooth contact analysis and standard calculation are used to determine the load capacity for the failure modes pitting, tooth root breakage, micropitting, and tooth flank fracture; analogies and differences between both approaches are shown. An example gearset is introduced to show the optimization potential that arises from using a combination of both methods. Difficulties in combining local approaches with standard methods are indicated. The example calculation demonstrates a valid possibility to optimize the gear design by using local tooth contact analysis while satisfying the requirement of documenting the load carrying capacity by standard calculations.

To achieve the requested quality, most gears today are ground. The usual grinding process includes treating the gear flank but disengaging before reaching the root rounding area. If the gear is premanufactured with a tool without protuberance, then at the position where the grinding tool retracts from the flank a grinding notch in the tooth root area is produced. Such a notch may increase the bending stresses in the root area, thus reducing the strength rating.

There was a time when no thinking person drove a car with more than 100,000 miles on a long-distance trip. A standard warranty was 12 months or 12,...