Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
Ball on plane rolling tests to evaluate gears contact fatigue
Submission Author:
Pedro Del Negro Tayer , SP
Co-Authors:
Pedro Del Negro Tayer, Newton Fukumasu, Rodrigo Stoeterau, Izabel Machado, Guilherme Antônio Assis Machado
Presenter: Pedro Del Negro Tayer
doi://10.26678/ABCM.COBEM2017.COB17-2080
Abstract
One of the possible mechanisms of gear failure can be related to the cyclic loading and, as a consequence, the fatigue occurrence. The onset of fatigue failure occurs due to stress intensifiers and it is generally observed on the fillet (bending fatigue) or on the flank contact region (contact fatigue). Gear fatigue evaluation is usually carried out by test rigs, which are expensive. An alternative method of contact fatigue test of gears is evaluated in this work, which consists of balls rolling on a plane (specimen). Two groups of specimens were manufactured to obtain microstructural features and mechanical properties similar to gears tooth's surface: a) with shot-peening and b) without shot-peening. The different features of specimens were tested by using an in house developed equipment to evaluate the rolling contact fatigue (RCF), which occurs on gears on its diametral pitch. Results indicate the occurrence of two failure modes: pitting and spalling. Also, the shot-peened group specimens presented lower fatigue life resistance for the analyzed conditions, which are not in agreement with the literature. This discrepancy may be related to the elevated contact pressure applied to accelerate the tests (3 GPa), which may promote a deeper subsurface damage, disregarding the protective effect shot-peening generated at the surface of the samples.
Keywords
gears, rolling contact fatigue, Shot peening, spalling, pitting
