Christof Gorgels

Manufacturing simulation of beveloid gears for the use in a general tooth contact analysis software

Beveloid gears, also known as conical involute gears, gain more and more importance in industrial practice. They are based on cylindrical gears but have a variable addendum modification along their tooth width. For marine transmissions beveloids are already deployed for a longer period, but there is a growing interest in this type of gears on the part of the automobile industry. Unfortunately the behavior of beveloid gears is not as well understood as the behavior of spur or bevel gears. Therefore the possibilities to evaluate these behaviors have to be enhanced. This paper shows a manufacturing simulation of beveloid gears and the usage of the generated geometries in a general tooth contact analysis program.

Simulation of bevel gear cutting with GPGPUs--performance and productivity

The desire for general purpose computation on graphics processing units caused the advance of new programming paradigms, e.g. OpenCL C/C++, CUDA C or the PGI Accelerator Model. In this paper, we apply these programming approaches to the software KegelSpan for simulating bevel gear cutting. This engineering application simulates an important manufacturing process in the automotive industry. The results obtained are compared to an OpenMP implementation on various hardware configurations. The discussion covers performance results, but also productivity of code development realized in this effort.

Tool life increase of coated carbide tools by micro blasting

In today’s production engineering nearly every cutting tool is coated. Since using the technology of coating different process chains for reconditioning have been developed. The last innovation is micro blasted coatings, which is the main topic of this paper. Concerning this topic influences on tool life have been investigated. Investigations on the tool life especially of hobbing tools were made thereby and coherences between coating bond, roughness and other attributes were discovered. The investigations were made with an aluminum oxide and a zirconium oxide as blasting abrasives and a variation of the blasting parameters pressure and period. The final result is an optimization of tool wear behavior by micro blasting of the coating.

Prognosis of the local tool wear in gear finish hobbing

Gear finish hobbing is a method for soft finishing of external cylindrical power transmission gears. The application of this process is required when the process chain of gear production is to be set up completely free of coolant. Since this finishing technology is relatively new, there is some practical experience, but no fundamental knowledge regarding economical process design. One challenge in process design is that unbalanced tool wear typically leads to geometrical deviations of the machined gear profile. The aim of the investigations described in this paper is to develop a wear model which is capable to predict the local tool wear of gear finish hobbing tools. This model is based on analogy cutting trials and geometrical analyses of the chip geometries in gear finish hobbing. The results of the model are validated by fly-cutting trials with different local loads on the tool. The validation shows that an optimization of the local tool wear development can be achieved by means of the prediction model. Therefore, an optimization of the technological process parameters can be carried out based on this model to reach an efficient process design.

Dynamic transmission error measurements of a drive train

Due to generally reducing the noise level of machines and automotive applications gear noise optimization becomes more important. To optimize the excitation of the gearing in the development process, tooth contact analysis software is used. The transmission error is most common to characterize the noise excitation of gear sets. Usually in automotive applications gear noise is influenced by the entire drive train system with all its components. Therefore, it is necessary to asses if the transmission error of the gear set correlates to the noise of the drive train. Aim of a project funded by the German Research Foundation (DFG) was to investigate the possibility to measure the transmission error for every step of assembly. The transmission error was measured for a gear set, the transmission and the drive train. The research object was the drive train of a light truck. This report presents the results of the completed project.

Tool Load during Multi-Flank Chip Formation

Tools used in cutting processes with multi-flank chip formation like gear hobbing or bevel gear cutting, often reach their tool life due to excessive wear at the tool corner radius. Tool wear depends on the strength of the cutting edge and on the thermal and mechanical load. The objective of this work is to analyze the thermal and mechanical tool load during multi-flank chip formation. As the tool load cannot be measured in the necessary high local resolution, a finite element based machining simulation is used to model the process of chip formation. The simulation is able to calculate the temperature and stress distribution along the cutting edge. For the examinations presented in this report the bevel gear cutting process for ring gears is simulated. The simulation results show a significant thermal and mechanical load maximum at the tool corner, where the maximal wear occurs in cutting.

Qualification of Coatings to Predict Wear Behavior of Micro Blasted Cutting Tools

In today’s production engineering nearly every cutting tool is coated. In the field of coating technology and tool treatment blasting is a common way to increase tool life or hold it on a constant level for several reconditioning steps. The latest innovation referring blasting are micro blasted coatings. For this technology a parameter variation was examined and the consequential tool life was compared with common testing method for tool systems in order to qualify the coating treatment. The investigations were carried out using an aluminum and zirconium oxide as blasting abrasive and by varying the blasting parameters pressure and duration. Finally, the treatment led to an optimized tool wear behavior due to micro blasting of the coating and the wear behavior could be referenced against the testing methods.

Influencing Densification of PM Gears

The powder metallurgical (PM) production offers the possibility for the efficient use of resources by near-netshape production. Due to remaining porosity after sintering, highly loaded PM gears have to be densified at the surface. In order to receive a satisfying surface strength, the densified layer has to be sufficiently deep. The depth of the densified layer is mainly influenced by the material stock of the blank and can be optimized by a variation of the stock along the tooth profile. Today, the material stock has to be designed in an iterative and time-consuming process.

Stiffness and load free transmission error for the Multi-Flexible-Body-Dynamics (MFBD) Simulation of a wind turbine gearbox using a FE-based tooth contact analysis

In most MFBD-systems it is possible to use a gear element to create a dynamic model of a wind turbine gearbox. This article shows a possibility to calculate the stiffness and the load free transmission error for this element using a FE-based tooth contact analysis.

Neue Ansätze zur Optimierung der Kegelradfertigung

Kurzfassung Kegelräder sind das wichtigste Maschinenelement für die drehsteife Leistungsübertragung in Winkelgetrieben. Um in allen Anwendungsbereichen ein günstiges Einsatzverhalten zu realisieren, werden Makro- und Kontaktgeometrie der Verzahnungen anwendungsspezifisch gestaltet. Dabei unterstützen Auslegungsprogramme den Konstrukteur. Allerdings weicht die mit idealen Maschineneinstellparametern berechnete von der tatsächlich gefertigten Flankentopographie, auf Grund von Maschinenungenauigkeiten, ab. Deshalb sind in einem Optimierungsschritt Korrekturen der Einstellungen zu ermitteln, mit welchen die gewünschte Flanke gefertigt werden kann. Die Wechselwirkungen einzelner Einstellungen sind teilweise nichtlinear. Daher wurde ein Complex-Algorithmus, ein Evolutionärer Algorithmus und ein Bergsteigerverfahren zur Optimierung der Parameter in einer Fertigungssimulation angewendet. Dieser Artikel beschreibt und vergleicht die drei Algorithmen. Es wird gezeigt, dass sich insbesondere der Complex-Algorithmus für die gestellte Aufgabe eignet.