A finite element model for stress analysis of lightweight spur gear drives based on thin-webbed and thin-rimmed gears

摘要

The design of thin-webbed and thin-rimmed gears represents an interesting topic for those applications where lightweight gear drives are required. A thin-rimmed design of a gear may cause an increment of the difference between the bending stress at the driving side and at the coast side of the tooth root. This may lead to a premature failure of the gear through the rim. A thin-webbed gear may reduce contact and bending stresses when an appropriated location of the gear web along the face width of the gear is selected. However, the thinner the gear web is, the larger the gear blank stresses are. These variations of bending and contact stresses due to the presence of thin rims and webs are considered by gear standards through some influence factors. However, some thinner rim or web designs may be beyond the scope of gear standards, some critical designs may require more accuracy or, simply, the attention of the designer may be focused on the gear blank stresses. An enhanced finite element model for stress analysis of thin-rimmed and thin-webbed gear drives is proposed for investigation of the effect of rim thickness, web thickness, and web location, on the gear contact and bending stresses, and on the gear blank stresses. Since the shaft deflections are related to the load distribution along the face width, the proposed finite element model includes the modelling of pinion and wheel shafts. Some numerical examples show the advantages of the proposed model.