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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Určení NVH parametrů skříně převodovky / NVH parameters determination of gearbox housing

Belák, Kristián January 2018 (has links)
This master’s thesis deals with determination of NVH parameters of the gearbox housing. Introductory part is focused on the necessary theoretical knowledge. Subsequently, it contains the modal analysis with the computational and experimental approach, which are being compared to each other. In the case of the computational approach, analysis of the influence of bolt pretension on the modal properties is also involved. The thesis continues with the harmonic analysis with the computational and experimental approach, including their mutual comparison. Based on these analyses, design modifications for improvement of the NVH parameters are designed at the end of the thesis, which are being compared to each other and to the original geometry, using the computational approach.
92

Konstrukční návrh zkušebního stavu s otevřenou smyčkou toku momentu pro experimentální ověření parametrů převodových ústrojí / Test Rig Design Proposal for the Experimental Validation of Transmission Parameters in Open Loop Torque Condition

Máca, Jiří January 2018 (has links)
This final diploma thesis deals with the issue of vibration and noise measurement of transmission devices. The research part describes the basic issues of noise and vibration generation, their measurement, as well as sources of vibrations in gear units. The practical part deals with the design proposal of the attachment of the experimental single-stage gearbox and the load dynamometer to the anechoic chamber including the drawings. Further, by checking the modal properties of the proposed test stand, using the finite element method, the analytical and numerical control of the torsional vibrations of the rotating parts with respect to the expected frequency ranges of use.
93

NVH převodového ústrojí pro elektromobily / NVH of gearbox housing for electric vehicles

David, Jan January 2020 (has links)
This master’s thesis deals with determination of NVH parameters of the gearbox housing for electric vehicle. The introduction part is focused on the theoretical knowledge of this issue. Subsequently, the deviations of geometry on the gearbox were measure by 3D scan method. The next part of thesis is focused on the modal analysis, which is solved by numerical approach and followed by experimental verification. During the numerical calculation solving, the influence of the screw preloading on the modal properties of the structure, was also taken into account. Numerical harmonic analysis was then performed and the results were compared with the experimental approach. The conclusion is devoted to material damping and comparison of the individual results.
94

Převodovka mobilní elektrocentrály / Gearbox for portable power generator

Kolka, Roman January 2008 (has links)
The submitted project deals with a complete design of a gearbox of a portable ground power generator designed for preflight preparation of helicopters. The gearbox has been designed to meet given specifications, which are based on required electrical parameters of the entire power unit and with regards to parameters of driving turbine engine. The introductory section deals with a kinematical design of transmission gears with regards to required parameters and design constraints. The kinematical design determines whole concept and resulting form of the gearbox. Next part deals with optimization of gearing, the design of wheel bearing, and design of oil system. The implementation part of the project consists in the engineering design of the gearbox, which was made in 3D environment Pro/Engineer. The design is reviewed and first operational results of manufactured and tested gearbox are discussed in the concluding section of this work.
95

Planetová převodovka pohonu desky karuselu poháněná direct-drive motorem. / Planetary Gear Box Used for Drive Table of Vertical Lathe Driven by the Direct Drive Engine

Žila, Slavomil January 2010 (has links)
The main theme of this thesis is an analysis, desing and construction of a planetary gearbox used for a drive of a vertical lathe table. The theoretical part of the thesis describes fundamental features and terms of planetary gearboxes and torque motors. In the next part of my work I design loose functioning of toothing. The calculation part of my work is processed in accordance with technical standards. The practical part of my work deals with a description of the project and the implementation of the device. The drawing documentation is processed with Cad system and it includes general assembly drawing and drawings of the three important components.
96

Posouzení tělesa převodovky a rámu pohonu kolesa kombinovaného skládkového stroje / Analysis of gearbox housing and drive frame of bucket-wheel stacker/reclaimer

Kuhejda, Lubomír January 2014 (has links)
This master’s thesis deals with the structural analysis of the gearbox housing and drive frame of bucket-wheel stacker/reclaimer. Theme is designed by Vítkovice Gearworks a.s. Objective of the work is to determine the size of the forces in the gears, bearings and perform strain stress analysis. The main part of the work is focused on creating finite element model in software NX I-Deas. The solution and evaluation is performed in software MSC Marc.
97

Parní kondenzační turbína s jedním regulovaným odběrem / Extraction Condensing Steam Turbine

Drápela, Jakub January 2016 (has links)
This diploma thesis describes a design of condensing steam turbine out of entered data of vapor parameters. There is selected a reaction blading type according to a conception of the company PBS Energo PLC. The turbine has one controlled extraction and three uncontrolled ones. The work also includes a proposal of thermal scheme, bearing and gearbox assignment. Furthermore there is also made a draft design of longitudinal section turbine
98

Theoretische und experimentelle Untersuchungen zum Gangspringen bei Schaltgetrieben

Schild, Andreas 28 April 2006 (has links)
Diese Arbeit beschäftigt sich mit den in konventionellen Handschaltgetrieben als auch in automatisierten Schaltgetrieben für die Funktion "Schalten/Leistungsfluss herstellen" verwendeten Zahnkupplungen. Einmal eingelegt soll der gewählte Gang bis zur Herausnahme durch den Fahrer den Leistungsfluss gewährleisten. Es gibt aber Getriebe, bei denen sich eine korrekt betätigte Schalteinrichtung während der Fahrt selbsttätig wieder entkoppelt. Mit der vorliegenden Arbeit wird dieses Problem, als „Gangspringen“ bezeichnet, erklärt und analysiert. Das Ergebnis dieser Arbeit sind Vorschläge und Möglichkeiten zur Vermeidung dieser Fehlfunktion.
99

MODELLBASERAD ANALYS AV AXIALGLIDLAGER I TUNGA LASTBILAR / Model-based analysis of thrust washer bearings in heavy trucks

Lavergren, Joel, Suoranta, Petri, Wranér, Hampus January 2016 (has links)
This Bachelor thesis at KTH Royal Institute of Technology in Stockholm covers a model-based analysis of thrust washer bearings in heavy trucks. This work treats Scania CV AB’s range-splitter gearbox. In this gearbox there are thrust washer bearings which are analyzed in this study. The purpose of the study is to examine the stresses the bearings are experiencing during load, determine which bearing (front or rear) that is most highly stressed, and discuss the cause for that. At large axial forces, which in turn lead to greater friction and thermal stress, there is a large risk for severe wear. Theoretically, there should not be any axial forces in a planetary gearbox with straight cut-gears, but because of the shape of the planet wheel carrier and the torque from the engine, the carrier and the needle bearings are distorted, which will cause an axial force. The axial force is not easily measured. Furthermore, it is also constantly changing during an actual driving sequence. Based on engineering judgement, the axial force was estimated to be 647 N. The axial force leads to all parts of the gearbox being pushed together axially, and cause friction forces to appear in surfaces that rotate relative each other. This process is analyzed with the FEM-program Ansys. Three possible scenarios were identified: (1) when the planetary wheel rotates relative the thrust washer bearing; (2) when the planetary wheel and needle bearing rotate relative the thrust washer bearing and (3) when the planet wheel carrier rotates relative the thrust washer bearing. The frictional heat power was simplified and analyzed as a heat power source and estimated to be 90 W. Cooling was modeled in Ansys as convection, with a film coefficient of 25 W/m2C. The initial temperatures used in the analysis were 22 and 90 °C. According to this, an equivalent stress of 12.3 MPa, and a maximum principal stress of 7.63 MPa, was located at the front thrust washer bearing. This occurs when the planet wheel and the needle bearing rotate relative to the thrust washer bearing, with an initial temperature of 90 °C. To validate the model, temperature sensors could be placed near the thrust washer bearings. However, since everything is rotating, this can be a difficult task. This report gives Scania a potential explanation to why the front and rear bearings in the gearbox are worn differently. / I det här kandidatexamensarbetet som genomfördes vid Kungliga Tekniska Högskolan i Stockholm gjordes en modellbaserad analys av axialglidlager som används i tunga lastbilar. Arbetet baserades på Scania CV ABs växellådor med range-splitter. I dessa sitter axialglidlager (även kallade brickor). Syftet var att undersöka hur stor påfrestning dessa utsätts för och försöka utröna vilken av brickorna (fram eller bak) som utsätts för störst belastning, samt diskutera vad detta skulle kunna bero på. Vid oönskade axiella krafter, som i sin tur leder till högre friktion och termoelastiska spänningar, är risken för nötning på brickorna stor. Teoretiskt sett ska det inte uppstå några axiella krafter i en planetväxel med rakkugg, men på grund av planethjulsbärarens utformning och det ingående momentet från motorn kan det uppstå en förvridning av hela bäraren och nållagren. Detta leder i sin tur till att en axiell kraft uppkommer. Denna kraft beräknades till 647 N med konservativa ingenjörsmässiga antaganden, eftersom axiella kraften inte kan mätas och ständigt varieras beroende på körprofil. Den axiella kraften medför att alla delar i planetväxeln pressas samman axiellt. En friktionskraft uppstår då mellan ytor som roterar i förhållande till varandra. Detta förlopp har analyserats med hjälp av FEM-programmet Ansys. Tre möjliga belastningsfall identifierades: (1) när planethjulet roterar mot axialglidlagret; (2) när planethjulet och nållagret roterar mot axialglidlagret, samt (3) när planethjulsbäraren roterar mot axialglidlagret. Den friktionsvärme som uppstår förenklades i modellen till en värmeeffekt på 90 W. Den värme som leds bort representerades som konvektion, med ett konvektionstal på 25 W/m2C. Som initialtemperaturer för FEM-analyserna användes 22 °C och 90 °C. En effektivspänning på 12,3 MPa och en största huvudspänning på 7,63 MPa uppstod i den främre brickan vid fallet när planethjul och nållager roterade mot axialglidlagret vid en intialtemperatur på 90 °C. För att kontrollera modellens rimlighet skulle temperaturgivare kunna installeras vid brickorna. Detta kan i praktiken dock bli svårt att genomföra då hela systemet roterar. Detta arbete ger Scania en möjlig förklaring till vad som skulle kunna orsaka en ojämn nötning fram och bak.
100

Anwendung prozessorientierter und taktratenabhängiger Bewegungen in Verarbeitungsmaschinen

Troll, Clemens, Majschak, Jens-Peter, Holowenko, Olaf, Ihlenfeldt, Steffen 15 November 2019 (has links)
Dieser Beitrag stellt einen Ansatz zur Steigerung der Ausbringung von Verarbeitungsmaschinen vor, der besonders bei der Umsetzung von Handhabungsaufgaben mittels dezentraler Antriebe wirkungsvoll angewandt werden kann. Ausgehend von einer Analyse bisheriger Ausbringungsbegrenzungen wird ein Konzept vorgestellt, welches Prozessmodelle, deren Nutzung in Bewegungsoptimierungen und die Abarbeitung mit Motion-Control-Systemen beinhaltet. Experimentelle Nachweise an Beispielprozessen, die den Erfolg des beschriebenen Ansatzes zeigen sowie weiterführende Gedanken bilden den Abschluss des Beitrages.

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