Calculation method for the pitting load carrying capacity of cylindrical gears based on local stresses in the lubricated rolling and sliding contact
Research Topic
| Short Title | Enhanced Pitting Load Carrying Capacity |
| Start of Project | Q4/2024 |
| Funding | FVA-Nr. 1040/IV Research Association for Drive Technology e.V., FVA |
| Project Partner | Laboratory for Machine Tools and Production Engineering WZL, RWTH Aachen |
| Contact | Dr.-Ing. T. Tobie |
Project Description
A reliable knowledge of the pitting load carrying capacity is a necessary prerequisite for the safe operation of gears. DIN 3990-2 and ISO 6336-2 provide a standardized calculation method for determining the pitting load carrying capacity. The calculation there is based on the Hertzian pressure of a characteristic mesh position as the decisive, damage-initiating load. In accordance with this procedure, a global pitting load carrying capacity of a gear is determined.
According to experimental investigations, further variables, besides the Hertzian pressure, influence the pitting load carrying capacity. These are not fully covered by the current standardized calculation methods for determining the pitting load carrying capacity in accordance with DIN 3990-2 and ISO 6336-2. However, there are possibilities in the literature for determining further stress components in the near-surface area of lubricated rolling and sliding contacts. A complete combination of these aspects to determine the pitting load carrying capacity has not yet been carried out.
The subject of this project is an extended calculation of the local pitting load carrying capacity in a method by combining known influencing variables. For this purpose, the application and implementation in the programs RIKOR (supervised by FZG, TU Munich) and STIRAK (supervised by WZL, RWTH-Aachen) is based on the findings of already completed research projects. A module-based calculation method with standardized interfaces is used to determine the local stress state starting at the material surface and extending into the material depth, taking into account e.g., the technical surface, the residual stress state and other factors. By applying comparative stress hypotheses and strength hypotheses, it is aimed to determine the local pitting load carrying capacity.