Eventos Anais de eventos
COBEF 2023
12th Brazilian Congress on Manufacturing Engineering
Influence of different gear flank deviation tolerance classes on the contact pattern
Submission Author:
Caio Felipe Siqueira Gomes , SP , Brazil
Co-Authors:
Caio Felipe Siqueira Gomes, Ronnie Rego, Tiago Colombo
Presenter: Caio Felipe Siqueira Gomes
doi://10.26678/ABCM.COBEF2023.COF23-0549
Abstract
The mobility electrification advent, mainly driven by the regulations for the reduction of greenhouse gases emission, has directly affected the vehicle systems' new design requirements, especially for the powertrain components. The current literature already cites that among the critical fields affecting the functional performance of future powertrain components is their geometrical accuracy. In the case of gears, the necessity of tighter manufacturing tolerances is related to the much higher rotational speeds involved in the electric motor operation than the internal combustion engine, besides being simultaneously quieter, torque-efficient, and operating with higher power densities. Although the gear flank tolerance classification system establishes the limits of tolerable gear pitch, profile, and helix deviations, there is no treatment in this system regarding how different deviation factors can differently influence the dynamic behavior of gears. Therefore, when gear standards suggest that high-speed gears require improved tolerance classes, all deviation factors are considered a group. In the case of mobility industries like the automotive, where high productivity rates and cost-reduction policies are crucial, tightening tolerance classes represent a challenge. In this context, the objective of the present study was the assessment of the influence of different gear deviation factors in tooth contact patterns to identify possible different effects among them. So, tooth contact analyses were performed by computational simulations for an ITA Geometry gear sample. The influence of gear manufacturing profile and helix slope deviation parameters of different gear tolerance classes in the flank contact pattern was investigated. The results have demonstrated that a tolerance class modification in helix slope deviation has a higher impact on the maximum Hertzian contact pressure than a class modification in profile slope deviation. When gear pair assembly deviations are also considered, the distinct influences are intensified. By identifying the most influential deviation parameters, it is intended to emphasize that the gear manufacturing sector does not have to tighter all tolerances to guarantee an adequate e-mobility gear operation. Concentrating the efforts only on the most impacting parameters may allow a good trade-off between operation behavior and manufacturing costs.
Keywords
gears, manufacturing deviations, Contact Stress, Electric Mobility
