This diploma thesis deals with the machining process of pinion gearing in the company Šmeral Brno a.s. The first part aims at the basic description of the thesis subject – the pinion. General gear machining technologies and its inspection is processed in the second part. The third part is focused on the description of the current machining process, its weaknesses and strengths. The main part consists of the machinery and tool choice, of the proposal of the gearing technological process for five-axis machining center and of the production time calculations. In conclusion, technological and economic impacts of the proposal are evaluated.

Temperature control is an essential aspect of gear design. Continuous research is going on to improve the efficiency of gear systems. Power losses or energy losses in these systems typically manifest themselves as increased temperatures and thus reducing the lifetime and overall performance of the system. Siemens Energy gas turbines produce powers of up to 63 Megawatts and as a result requires a gearbox which can transmit such high powers. A double helical parallel shaft gearbox is mostly used for this purpose. With sufficient cooling methods and by reducing the losses in the gearboxes even by a minute percent, can increase the efficiency of gearbox which in turn will increase the efficiency of the whole powerplant. This will make the consumer even more profitable in the long run. A mathematical power loss model for the double helical gears in mesh was developed in MATLAB. This was followed by a finite element steady state thermal analysis in ANSYS. The boundary conditions and the results of the analysis are discussed and a few design changes to reduce the gear losses are suggested. / Temperaturkontroll är en viktig aspekt av växeldesign. Kontinuerlig forskning pågår för att förbättra växelsystemens effektivitet. Effektförluster eller energiförluster i dessa system manifesterar sig vanligtvis som ökade temperaturer och minskar därmed systemets livslängd och totala prestanda.  Siemens Energy gasturbiner producerar effekter på upp till 63 megawatt och kräver därför en växellåda som kan överföra så höga effekter. En växellåda med dubbel spiralformad parallellaxel används mest för detta ändamål. Med tillräckliga kylmetoder och genom att minska förlusterna i växellådorna även med en minutprocent, kan öka växellådans effektivitet vilket i sin tur kommer att öka effektiviteten i hela kraftverket. Detta kommer att göra konsumenten ännu mer lönsam på lång sikt. En matematisk effektförlustmodell för de dubbla spiralformade kugghjulen i nät utvecklades i MATLAB. Detta följdes av ett finit element steady state termisk analys i ANSYS. Randvillkoren och resultaten av analysen diskuteras och några designändringar för att minska växelförlusterna föreslås.

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For dimensions of crankshaft drive Zetor engine, which is solve by a helical gear drive will be created a dynamic model in MBS (multi body system) and perform analyses. The same way will be created a dynamic model for a spur gear system. In conclusion will be confrontation both of these drive solutions.

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Ce travail vise à prédire le comportement dynamique de transmissions par engrenages supportées par des paliers hydrodynamiques, semblables à celles utilisées dans le domaine de la propulsion navale. Un modèle couplé de transmission mécanique est présenté ; il traite la plupart des interactions possibles entre les engrenages, les arbres et les paliers. Un élément d’engrenages à dentures larges, avec raideur non linéaire et dépendante du temps, est combiné à des éléments finis de poutre alors que la contribution des paliers est introduite par la résolution directe de l’équation de REYNOLDS et d’un model thermique simplifié. A cause des jeux de fonctionnement des paliers, une attention particulière a été portée à la définition de l’état de référence et des degrés de liberté. La réponse du système est calculée par la combinaison d’un schéma d’intégration temporelle, d’une méthode de NEWTON-RAPHSON et d’un algorithme de contact normal unilatéral de manière à ce que les conditions de contact aux paliers et entre les dents soient simultanément traitées. Les résultats de simulation sont comparés à des mesures réalisées sur un banc d’essai de haute précision possédant un train simple étage en dentures droites et hélicoïdales, supporté par des paliers lisses de type hydrodynamique. Les comparaisons fournissent un bon accord et aboutissent à la validation du modèle de couplage tant sur les aspects globaux que locaux. Bon nombre de résultats sont également présentés, qui montrent que certains paramètres, bien souvent ignorés dans les modèles de la littérature, tels que la position de la zone d’alimentation des paliers, la température de lubrifiant dans les paliers, les accouplements avec l’environnement extérieur peuvent fortement modifier l’équilibre statique et le comportement dynamique du système, jusqu’aux contacts entre les dents. / The present work is aimed at predicting the dynamic behaviour of geared transmissions supported by hydrodynamic journal bearings, similar to those used in naval propulsion. A global model of mechanical transmissions is introduced which deals with most of the possible interactions between gears, shafts and hydrodynamic journal bearings. A specific element for wide-faced gears with non linear time-varying mesh stiffness and tooth shape deviations is combined with shaft finite elements whereas the bearing contributions are introduced based on the direct solution of REYNOLDS’ equation and a simple thermal model. Because of the large bearing clearances, particular attention has been paid to the definition of the degrees-of-freedom and their datum. Solutions are derived by combining a time-step integration scheme, a NEWTON-RAPHSON method and a normal contact algorithm in such a way that the contact conditions in the bearings and on the gear teeth are simultaneously dealt with. The simulation results are compared with the measurement obtained on a high-precision test rig with single stage spur and helical gears supported by hydrodynamic journal bearings. The experimental and simulation results compare well thus validating the simulation strategy both at the global and local scales. A number of results are presented which show that parameters often discarded in global models such as the location of the oil inlet area, the oil temperature in the bearings and external couplings with mechanical parts can be influential on the static and dynamic behaviour of the system.

This master’s thesis is focused on the compilation of a computational modelling of gear mesh engagement dynamics of a spur gear by MBS approach. The user input is the specific geometry of gears, the operating speed, and the load torque. The output are the forces in the gear engagement and the reaction of the forces in the wheel bearings depending on the change in the stiffness of the gear due to the changing number of teeth in the engagement and the change in the axial distance. This model is characterized by a fast and relatively accurate calculation in the time domain. This means that it can react to changes in parameters during simulation such as axial distance, speed, and torque.