No description available.

No description available.

No description available.

No description available.

Advanced technologies for the automotive industry require improved designed precision in different areas. Research is needed in order to meet customer demand and satisfaction to increase durability, efficiency, and reliability. That is why continuous development in transmission system has been an exciting topic for many years. The gears in the transmission system demand high resistance against repeated loads acting on the teeth and the ability to engage without energy loss. The intention is to support that effort by investigating seven design cases of a parallel helical gear pair. This master thesis aims to study a gear design concept of adding a supporting ring to reduce the root bending- and contact stresses. To implement this study, seven different design cases were modelled to study the effect of changing the design. One or two support ring structures were added, or the thickness was increased of the gear considered exposed to high stresses. The purpose is to gain a comparative advantage in the automotive industry. M1 is a reference standard design, while the other models (M2-M5/P1-P3) are modified designs with additional rings or changed in thickness. Simulation is an effective and an useful tool to understand and visualize how the complex interaction of the transmission component appears to be. A finite element method (FEM) program was used to investigate these models. The gear pairs were imported into the pre-processor ANSA, the FEM program Abaqus 2017 was used as a solver, and the results were extracted from the post-processor META. To support the aim of this thesis, two of the seven FEM models were validated against a specialized gear calculated program, WindowsLDP, in order to determine the robustness of the simulation models. The transmission error (TE) measurements, root bending- and contact stresses were observed for the validation. Introducing the different models M3-M5 and P1-P3, the root and contact stresses were reduced by 1.2-4.4 and 0.07-4.3 %, respectively, compared to M1. The transmission error TE could differ as much as 85% in M2-M3 as compared to M1. Systematic errors were generated in model M2, therefore the low root stresses obtained in M2 should be considered carefully. Implementing the so-called misalignment measurement, tilting parameter, microgeometry, and profile modification related to crowning and tip relief is discussed and believed to reduce TE measurements, root- and contact stresses. These modifications have not been studied in this thesis. The LDP results showed a trend of higher values compared to the FEM results, which was suggested to be further investigated in the future. / Dagens avancerade teknik inom fordonsindustrin kräver förbättrad precision hos konstruktioner inom olika områden. Forskning behövs för att möta kundernas efterfrågan och för att öka hållbarhet, effektivitet och tillförlitlighet. Detta är varför kontinuerlig utvecklingen av växellådssystem har varit ett hett ämne i många år. Kugghjulstransmission skall ha högt motstånd mot upprepande belastning som förekommer på tänderna och skall även ha en minimal energiförlust. Detta examensarbete siktar mot att stödja den fortsatta utvecklingen inom området genom en fallstudie, mer specifikt för att studera sju olika kugghjulsmodeller som behandlar ett parallellt spiralformade kugghjul. Målet med detta examensarbete är att studera ett kugghjulskoncept där en ring appliceras för att reducera rot- och kontaktspänningar. Utförandet sker genom att studera sju olika modeller, för att veta hur stor påverkan designen utgör. En eller två stödringstrukturer appliceras, eller att öka kuggbredden på det kugghjul som anses vara det mest kritiska för höga spänningar. Denna studie görs för att kugghjulstillverkaren ska vara i utvecklingens framkant och kunna konkurrera inom fordonsindustrin. M1 ären referens och standard designmodell, medan de andra modellerna (M2-M5/ P1-P3) är modifierade design där med ytterligare ringar eller ändrad kuggbredd. Simulering är en effektiv metod för att förstå och visualisera komplexiteten av komponenter inom växellådan. Ett finita elementmetodens program användes för att undersöka dessa modeller, genom att importera geometrierna till pre-processorn ANSA, där Abaqus 2017 användes som en lösare, där sedan resultaten extraheras från post-processorn META. För att stödja denna studien användes två av de sju FEM-modellerna till att valideras mot ett annat specialiserat kugghjulsprogram inom kuggberäkning som heter WindowsLDP. Detta med avsikt att fastställa simuleringsmodellernas robusthet. Det så kallade överföringsfelet, rotböjnings- och kontaktspänningarna var ingående parametrar som behandlades under valideringen. Modellerna M3-M5/P1-P3 introducerades, där rotböjsspänningen och kontaktspänningen reducerades med 1.2-4.4 och 0.07-4.3% när de jämfördes med M1. Överföringsfelet (TE) kunde skilja upp mot 85% mellan M2-M3 jämfört med M1. Ett systematiskt fel uppstod i modell M2, modellens robusthet kunde därmed ej fastställas, då modellens resultat bör övervägas noggrant. Införande av så kallade växelförskjutning, lutning/vippning parametrar, mikrogeometrier och profilmodifieringen relaterat till kronning och tipavlastning, kommer att genera minskade TE-mätningar samt rot- och kontaktspänningar för de spiralformade kugghjulen. Dessa ämne har ej studerats under detta examensarbete. LDP-resultaten visade högre värden relativt jämfört med de FEM resultat, där en trend kunde observeras. Slutsatsen föreslog att detta bör undersökas ytterligare i framtiden.

This diploma thesis primarily deals with the transmission error issue which is one of the dominant sources of vibration in gear pairs and transmission systems. The vibrations subsequently generate noise which is often subjected to increasingly stricter demands across the industry, including the automotive one. It turns out that reducing the peak-to-peak value of the transmission error has a beneficial effect on the vibro-acoustic properties of gears and gear pairs. This thesis aims to determine the transmission error under static conditions, since a gear pair with a low static transmission error is a good assumption for a low transmission error even under dynamic effects. The resulting values of the transmission error can be influenced already during the design of the gear macro-geometry. It is also suitable to apply micro-geometric adjustments – modifications to the gear teeth. For this reason, the search part of the thesis is dedicated to theoretical knowledge, especially concerning the geometry of gears, modifications of teeth and the overall transmission error and its determination. The transmission error can be determined in several ways, including a technical experiment. However, due to time and financial reasons, this is not always possible, and therefore, the possibility of using numerical simulations is offered. In this thesis, the approach using stress-strain quasi-static contact analysis using the finite element method in Ansys Workbench software is used. The advantage is, among other things, a good comparability of results. The input to the FEM analysis is 3D CAD geometry – in this case, it is specifically a helical gear pair with parallel axes. The model/assembly of this gear pair is created in PTC Creo software fully parametrically, so it is possible to generate arbitrary gear pair configurations by changing the input parameters, which significantly saves time. At the end of this diploma thesis, the stress-strain analysis of various gear configurations is evaluated, with respect to the equivalent stress and contact pressure. Furthermore, the static transmission error – its graphs and peak-to-peak values – is determined from FEM analyses for different gear geometry, including tooth modifications, and for various loading torques. Last but not least, the effects of contact/overlap ratio and centre distance are evaluated.