Reducing scrapping of gears by assessment of tip contact threshold torque

While striving for more competitive products as well as reaching the Global Sustainable Development Goals, automotive powertrain manufacturers increase the demands on gears, which translates to decreased manufacturing error tolerances. Too tight tolerances may, however, counteract the goal if it leads to increased material and energy consumption due to unjustified scrapping. This paper presents a method to prevent unjustified scrapping by comparing the severity of different manufacturing error tolerances by means of the tip contact threshold torque. Curve fits are shown to be accurate and helpful to assess the outcome of a produced batch of gears. A case study is made where the method is used with measured data from the industry. It can be concluded from the investigation that considerable amounts of scrapping can be avoided by consideration of the threshold torque.

Green Coalescent Synthesis Based on the Design for Environment (DfE) Principles: Brazilian Experience

Coalescents are compounds with a high potential for generating tropospheric ozone, which causes adverse effects on humans and their surroundings. This study designed a coalescent for decorative paints that reached technical levels equivalent to those obtained by StC, a product on the market, but with better environmental and economic performance. The strategy adopted in creating the green coalescent (GrC) improved film formation and reduced the product’s atmospheric emission rate. Regarding the environmental performance, GrC outperformed StC in terms of water consumption, global warming potential, and human toxicity by 30%, 35%, and 91%, but had a high smog formation potential even with a reduced loss to the air. The redesign of the molecule gave rise to AGrC, which achieved a more homogeneous environmental performance. The results of an economic analysis indicated that the procedures adopted to reduce environmental impacts could also make the coalescent more competitive if the lowest market prices were practiced. On the other hand, if the products are sold at high prices, the paint industry tends to privilege the economic dimension and disregard environmental performance for decision purposes. This research succeeded in reconciling technical functions and aspects related to sustainability to design more competitive products in the Brazilian market.