Improved tolerance and load capacity calculation in STplus based on standard-compliant approaches for extending DIN 3990 and ISO 6336
Research Topic
| Short Title | Tolerance and extended load carrying capacity in STplus |
| Start of Project | Q4/2025 |
| Funding | FVA-Nr. 241/XVII Research Association for Drive Technology e.V., FVA |
| Contact | Dr.-Ing. M. Otto |
Project Description
The objective of the project is to extend the load-carrying capacity calculation in STplus [Rot23] by incorporating calculation methods and approaches that go beyond the scope of the standards DIN 3990 / ISO 6336 [DIN87, ISO19]. Among other things, the influence of interference fits on tooth root strength and profile deviations according to [Leo22] is to be implemented. Additionally, an enhanced scuffing load capacity calculation based on local lubricant film thickness according to 598 II [Joo18] is to be integrated into STplus. These extensions will be complemented by an approach to consider the case hardening depth in the load-carrying capacity calculation according to 271 I [Tob01], in which project-specific factors are determined and incorporated into calculations based on DIN / ISO standards.
depth including tolerance range [FVA271I]
In addition, a study on the influence of geometric tolerances is to be conducted. This theoretical study will examine the impact of tolerable parameters on load-carrying capacity. As a result, a method for quality variation will be developed and thoroughly documented to enable its implementation in STplus and other software. STplus offers the capability to perform load-carrying capacity calculations based on a wide range of industry-relevant standards and classifiers. An up-to-date standard catalog is essential for gearbox design in the industry. As part of the project, the standards and classifiers currently available in STplus will be updated to their latest versions. The result will be a version of STplus that delivers competitive calculation results through the update of existing standards and classifiers. Furthermore, it will enable fast and efficient loadcarrying capacity calculations that go beyond the limitations of current standards, thereby providing results that more closely reflect real-world conditions. The resulting less conservative estimation of load capacity reduces the use of resources as well as the costs associated with gear manufacturing.
Literatur
[DIN87] DIN 3990:1987: Tragfähigkeitsberechnung von Stirnrädern (1987).
[ISO19] ISO 6336-1:2019: Calculation of load capacity of spur and helical gears - Part 1: Basic principles, introduction and general influence factors (2019).
[Joo18] Joop, M.; Ittenson, H.; Tenberge, P.; Bartel, D.: FVA-Nr. 598/II - Heft 1306 - Abschlussbericht - Örtliche Fresstragfähigkeit II. Forschungsvereinigung Antriebstechnik e.V., Frankfurt/Main (2018).
[Leo22] Leonhardt, C.: FVA-Nr. 797/I - Heft 1434 - Abschlussbericht - Gefügte Stirnräder - Einfluss von Querpressverbänden auf die Zahnfußtragfähigkeit außenverzahnter Stirnradverzahnungen. Forschungsvereinigung Antriebstechnik e.V., Frankfurt/Main (2022).
[Rot23] Rothemund, M.; Otto, M.; Stahl, K.: FVA-Nr. 241/XVI - Heft 1574 - Abschlussbericht - Ableitung fertigungsgerechter Geometrien, Darstellungen und Schnittstellen für die moderne Zahnradherstellung. Forschungsvereinigung Antriebstechnik e.V., Frankfurt/Main (2023).
[Tob01] Tobie, T.; Oster, P.; Höhn, B.-R.: FVA-Nr. 271/I - Abschlussbericht - Heft 622 - Härtetiefe-Großzahnräder. Forschungsvereinigung Antriebstechnik e.V., Frankfurt/Main (2001).