B. Sobolewski

Method of spiral bevel gear tooth contact analysis performed in CAD environment

Purpose – The purpose of this paper is to present the use of a CAD system for the analysis of meshing of spiral bevel gears. Design/methodology/approach – The TCA computer programs are based on a purely mathematical model and require to get the numerical solution of a set of nonlinear equations. There are situations that the programs fail to obtain the proper solution. In such cases, geometrical gear models defined in CAD environment prove to be a good choice. This paper describes a tool for analyzing tooth contact and transmission errors of spiral bevel gear sets with tooth flanks represented as CAD free-form surfaces. Findings – A new method has been proposed to keep those surfaces in continuous contact in the whole range of meshing of a mating tooth pair. During meshing, the points of contact as well as the corresponding angles of rotation of both the pinion and the ring gear are recorded. Thus, the tooth contact path as well as the motion transmission error graph is determined. Then, the contact patte...

Manufacturing of aircraft engine transmission gear with SLS (DMLS) method

Purpose The purpose of this paper is to present the methodology for manufacturing of aircraft transmission gears using incremental method of rapid prototyping (RP) – direct metal laser sintering (DMLS). The production of prototypes from metallic powders using described system allows the execution of final elements of complex structures with additional economic impacts. Design/methodology/approach The paper describes the use of selective laser sintering method (DMLS) by EOS Company. Whole chain of production of prototype is presented with the addition of geometric accuracy measurements by blue light laser device. Findings Presented in the research analysis of SLS/SLM technologies as rapid manufacturing systems shows that they can be applied in the production of prototypes used in the manufacturing process of gears for propulsion systems in aviation industry. Also, very important is the geometrical accuracy of gear prototypes produced by incremental methods. It determines subsequent treatment steps for aircraft propulsion system gears. Practical Implications The use of RP techniques as an alternative for conventionally used manufacturing method has mainly an economic impact related to the cost of time-consuming process and amount of defected elements appearing in serial production. Originality/value This paper presents possibility to use RP – DMLS system – for propulsion elements of aircraft structure. This research is original because of the complex description of the whole chain of manufacturing process. Additionally, geometrical accuracy measurement methodology by blue light presented with the RP method of manufacturing gives the research a unique characteristic.

Methodology of measurement aeronautical bevel gears using an optical scanner ATOS II Triple Scan

Properly prepared and carried out the measurement process of bevel gears determines its accuracy and productivity. This also has an influence on the final accuracy of bevel gears and the production costs of aeronautical gearbox. In the process of assessing the accuracy of manufacturing, majority of manufacturers of bevel gears use specialized contact coordinate measuring machines. The application of such machines as well as specialized programs dedicated to measuring the geometry of bevel gears are authoritative but in turns this requires substantial financial resources for the purchase of machinery. Thereby, this causes the limitation only of the gear assortment. Therefore, this article depicts different perspective on measurements of bevel gears using a universal measuring

The determination of accuracy of the demonstrator of aeronautic bevel gearbox, accomplished by selected rapid prototyping techniques using an optical scanner Atos II Triple Scan

Designing and manufacturing of aeronautic bevel gearboxes is a complicated and time-consuming process because of complex kinematics of the machining process as well as numbers of manufacturing methods. Machine manufacturers usually provide algorithms used in manufacture process. This requires substantial financial resources and, in consequence, it increases the costs of production. Using other commonly available calculation algorithm requires a lot of studies to verify whether the proposed gearbox works correctly. In order to reduce the manufacturing costs of prototypes, it is possible to use Rapid Prototyping methods. Using both Rapid Prototyping techniques and coordinate optical measurements enables to verify the correctness of assumptions made in the initial stage of product designing. This approach reduces significantly both prototyping time and manufacturing costs. In order to ensure the effectiveness of prototyping process, it is essential to provide the accuracy of manufactured prototypes. That is the reason why it is necessary to determine manufacturing methods that will ensure the highest geometric accuracy. The study presents the modelling and manufacturing process of aeronautic bevel gear of demonstrator taking into consideration the accuracy of selected Rapid Prototyping methods. The gear modelling is based on machining simulation method conducted in Autodesk Inventor. The measurement results are shown in displacement maps obtained with an optical scanner Atos II Triple Scan and universal GOM Inspect Professional software, which determines the prototype accuracy in relation to 3D-CAD models.