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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.
71

Návrh vřeteníku soustruhu / Design of spindle for lathe

Sovadina, František January 2021 (has links)
The thesis deals with the design and construction of headstocks of a turning centre. The aim is to design a spindle with an output of 20 kW and a maximum speed of 5000 1/min. The research part of the thesis is focused on the description of the basic parameters of the headstock and turning centres needed for the construction of the headstock and contains an analysis of the available spindles on the market. The next part of the thesis deals with the selection and calculation of cutting conditions and the necessary parameters. Analytical calculations are then verified using FEM analysis. At the end of the thesis, a 3D model was developed and headstock drawing documentation.
72

Zvýšení produktivity a kvality vybraných vyráběných dílů / On the increase of productivity and quality of selected manufactured parts

Siclon, Léonard January 2011 (has links)
This document is about the work conducted during four months in the company Poclain Hydraulics. The aim was to improve the productivity of the turning operation on the cams MK04, in a factory environment but with the support of a laboratory. Was also in mind to improve the quality of the part and diminish or eliminate the unbroken chips. In that purpose the trajectories have been analyzed and modified, the cutting conditions studied and adapted, some tool changed, etc. The final result was an improvement of productivity to 140%, an amelioration of the chip breaking and of the part’s quality, leading to significant savings on the process.
73

Pohon vřeten pětivřetenového soustružnického automatu / Desingn of independent drives for five-spindle automatic lathe

Pavelka, Radomil January 2014 (has links)
The subject of the thesis is design of independent spindle drive for multi-spindle automatic lathe MORI-SAY TMZ 520 CNC manufactured by TAJMAC-ZPS. The thesis will introduce the representatives of manufacturing program of TAJMAC-ZPS multi-spindle automatic lathes division and there will be a brief description of their main constructional parts. The main objective of the thesis is an engineering design of testing device which will be bulit for verification of the correct drive concept. There is also many calculations and detailed description of the engineering design. The testing device is made for internal needs of TAJMAC-ZPS.
74

Konstrukce vřeten vícevřetenového soustružnického automatu / Design of spindles for multi-spindle automatic lathe

Kráčmar, Tomáš January 2016 (has links)
This master‘s thesis contains a design of multi-spindle automatic lathe spindles for the work of the rods maximum diameter of 7 mm. The work deals with a new concept of the drive spindle, where the spindles are driven by external asynchronous motor through the gears with internal teeth attached to the outside of the spindle drum instead of the current method of driven by central coaxial shaft. The thesis research of multi-spindle lathes including a description of the main nodes, design, strength calculations, bearing durability and a simulation model for simulation acceleration and load drives and spindles from the cutting process.
75

Исследование износа и стойкости токарных резцов с алмазоподобным покрытием : магистерская диссертация / Investigation of wear and resistance of cutting tools with a diamond-like coating

Кульпина, К. А., Kulpina, K. A. January 2021 (has links)
Магистерская диссертация выполнена на тему: «Исследование износа и стойкости токарных резцов с алмазоподобным покрытием». Расчётно-пояснительная записка содержит 94 листа, 86 рисунков, 6 таблиц, 23 источника, 1 приложение. Объектом исследования данной работы являются токарные резцы с алмазоподобным покрытием. Цель работы – определить наиболее благоприятные условия работы токарных резцов с алмазоподобным покрытием. В результате выполнения работы были проведены исследования износа алмазоподобного покрытия на токарных резцах, построены и проанализированы графики зависимостей этих износов. Проведен анализ полученных результатов и выдвинута гипотеза об еще одной возможной причине разрушения покрытия, в то время как остальные известные причины устранены. Разработаны конструкции токарных резцов и проведено исследование предлагаемой гипотезы. По результатам исследования проведен расчет прочности и подтверждена предлагаемая гипотеза. / The master's dissertation is carried out on the topic: "Investigation of wear and resistance of cutting tools with a diamond-like coating". The settlement and explanatory note contains 94 sheets, 86 figures, 6 tables, 23 sources, 1 attachment. The object of research in this work is diamond-coated lathe tools. The purpose of the work is to determine the most favorable working conditions for lathe tools with a diamond-like coating. In the course of the work, the study of the wear of the diamond-like coating on lathe tools at various cutting modes was carried out, the graphs of the dependences of these wear in time were built and analyzed. The analysis of the results obtained is carried out and a hypothesis is put forward about another possible cause of the destruction of the coating, while the other known causes have been eliminated. To confirm the hypothesis, the designs of lathe tools were developed and a study was carried out. According to the results of the study, the strength calculation was carried out, the proposed hypothesis was confirmed.
76

Разработка технических средств уменьшения температурных погрешностей обработки на высокоскоростных токарных станках : магистерская диссертация / Development of technical means to reduce the temperature errors of processing on high-speed lathes

Оссовская, Е. С., Ossovskaya, E. S. January 2021 (has links)
В начале работы рассматриваются факторы, которые влияют на точность станков, и учитывается роль температурных деформаций для обеспечения точности обработки на металлорежущих станках. Наблюдается, что большое влияние на точность станков оказывают тепловые деформации. После этого познакомились со способами уменьшения температурных деформаций узлов станков, которые используются в данное время, и с техническими средствами их реализации. Рассмотрев существующие системы, мы определили задачу разработки системы термостабилизации с водяным охлаждением электрошпинделя. Для начала мы модернизировали существующую систему термостабилизации шпиндельного узла, в которую включили цепь дифференциала. Потом, обозначив достоинства и целесообразность комбинированного управления, разработали более совершенную систему термостабилизации шпиндельного узла. Далее рассмотрен другой фактор погрешности при обработке – это инструмент, в нашем случае резец для токарной обработки. Для него была разработана система охлаждения с учетом нагрева пластины. / At the beginning of the work, the factors that affect the accuracy of machine tools are considered, and the role of temperature deformations is taken into account to ensure the accuracy of processing on metal-cutting machines. It is observed that thermal deformations have a great influence on the accuracy of machine tools. After that, we got acquainted with the ways to reduce the temperature deformations of machine components that are currently used, and with the technical means of their implementation. Having considered the existing systems, we determined the task of developing a thermal stabilization system with a water-cooled electric spindle. To begin with, we upgraded the existing thermal stabilization system of the spindle assembly, which included a differential circuit. Then, having identified the advantages and expediency of combined control, we developed a more advanced system of thermal stabilization of the spindle assembly. Next, another factor of error in processing is considered – this is a tool, in our case, a cutter for turning. A cooling system was developed for it, taking into account the heating of the plate.
77

Новое оборудование для механической обработки колесных пар вагонов и локомотивов без выкатки : магистерская диссертация / New equipment for mechanical processing of wheelsets for wagons and locomotives without rolling-out

Баженов, С. Е., Bazhenov, S. E. January 2022 (has links)
В представленной выпускной квалификационная работа по теме «Новое оборудование для механической обработки колесных пар вагонов и локомотивов без выкатки» рассмотрены виды и способы контроля износа железнодорожных колес, разработаны колесотокарные станки и оборудование, необходимое для их использования. Описан колесофрезерный станок, обладающий по сравнению с колесотокарным определенными преимуществами, рассматриваются вопросы, касающиеся проектирования соответствующего режущего инструмента. Выполнены расчеты, обосновывающие принятые конструктивные решения. / In the presented graduate qualification work on "New equipment for mechanical processing of wheelsets for wagons and locomotives without rolling-out" types and methods of controlling the wear of wheelsets are reviewed, wheel lathes and equipment required for their use are developed. The paper gives the description of a wheel-milling machine, which has some advantages compared to a wheel lathe, and deals with the problems concerning the design of the appropriate cutting tools. Calculations are made, which substantiate the adopted design solutions.
78

Aplicação da transformada de Hilbert-Huang na análise das vibrações dos motores de indução de máquinas ferramentas. / Hilbert-Huang transform application in analysis of machine tools induction motors vibrations.

Marques, José Roberto 22 May 2013 (has links)
Este trabalho tem seu foco na monitoração dos processos de usinagem das máquinas ferramentas sem a utilização de sensores dedicados à medição direta das grandezas mecânicas envolvidas no processo de usinagem em si. Assim sendo, optou-se por um método de medição indireta utilizando um estimador de potência e torque baseado nas grandezas elétricas na entrada de energia do motor de indução da máquina ferramenta. O núcleo central do trabalho consiste na medição de processos de usinagem utilizando um dinamômetro de alta precisão próprio para máquina ferramenta para obter os valores médios e os modos de vibração do processo máquina ferramenta-usinagem e fazer a confrontação com os mesmos dados obtidos pelo estimador de torque. A pesquisa realizada utilizou ferramentas clássicas de processamento de sinais, como é o caso da FFT, assim como duas poderosas ferramentas atuais, a transformada de wavelet (WT) e a transformada de Hilbert-Huang (HHT). Em adição foi utilizado um processo de otimização para a determinação dos parâmetros do motor de indução on-line baseado em uma metaheurística denominada busca de harmonia (Harmony Search HS) / This work focuses on monitoring the machining processes in machine tools without the use of dedicated transducers to directly measure mechanicals quantities of the machining process. The approached method used the option of measuring the power and torque through a estimator based in the electrical quantities in the input of the induction motor used by machine tool. The core of the work consists in the measuring the mechanical processes of machining using a high precision dynamometer specified to machine tool to get the average values of mechanical quantities and the vibration modes of the set machine tool-machining process, the objective is to compare the same data group got from dynamometer and estimator. The research data was based on classical analysis tool such as Fourier transform (FFT) and on modern powerful tools such as wavelet transforms (WT) and Hilbert-Huang transform (HHT). To refine the measuring process of average values of torque and power using the induction motor a method to estimates the motor parameters was added based on an optimization method named harmony search (HS).
79

Aplicação da transformada de Hilbert-Huang na análise das vibrações dos motores de indução de máquinas ferramentas. / Hilbert-Huang transform application in analysis of machine tools induction motors vibrations.

José Roberto Marques 22 May 2013 (has links)
Este trabalho tem seu foco na monitoração dos processos de usinagem das máquinas ferramentas sem a utilização de sensores dedicados à medição direta das grandezas mecânicas envolvidas no processo de usinagem em si. Assim sendo, optou-se por um método de medição indireta utilizando um estimador de potência e torque baseado nas grandezas elétricas na entrada de energia do motor de indução da máquina ferramenta. O núcleo central do trabalho consiste na medição de processos de usinagem utilizando um dinamômetro de alta precisão próprio para máquina ferramenta para obter os valores médios e os modos de vibração do processo máquina ferramenta-usinagem e fazer a confrontação com os mesmos dados obtidos pelo estimador de torque. A pesquisa realizada utilizou ferramentas clássicas de processamento de sinais, como é o caso da FFT, assim como duas poderosas ferramentas atuais, a transformada de wavelet (WT) e a transformada de Hilbert-Huang (HHT). Em adição foi utilizado um processo de otimização para a determinação dos parâmetros do motor de indução on-line baseado em uma metaheurística denominada busca de harmonia (Harmony Search HS) / This work focuses on monitoring the machining processes in machine tools without the use of dedicated transducers to directly measure mechanicals quantities of the machining process. The approached method used the option of measuring the power and torque through a estimator based in the electrical quantities in the input of the induction motor used by machine tool. The core of the work consists in the measuring the mechanical processes of machining using a high precision dynamometer specified to machine tool to get the average values of mechanical quantities and the vibration modes of the set machine tool-machining process, the objective is to compare the same data group got from dynamometer and estimator. The research data was based on classical analysis tool such as Fourier transform (FFT) and on modern powerful tools such as wavelet transforms (WT) and Hilbert-Huang transform (HHT). To refine the measuring process of average values of torque and power using the induction motor a method to estimates the motor parameters was added based on an optimization method named harmony search (HS).
80

ON-MACHINE MEASUREMENT OF WORKPIECE FORM ERRORS IN ULTRAPRECISION MACHINING

Gomersall, Fiona January 2016 (has links)
Ultraprecision single point diamond turning is required to produce parts with sub-nanometer surface roughness and sub-micrometer surface profiles tolerances. These parts have applications in the optics industry, where tight form accuracy is required while achieving high surface finish quality. Generally, parts can be polished to achieve the desired finish, but then the form accuracy can easily be lost in the process rendering the part unusable. Currently, most mid to low spatial frequency surface finish errors are inspected offline. This is done by physically removing the workpiece from the machining fixture and mounting the part in a laser interferometer. This action introduces errors in itself through minute differences in the support conditions of the over constrained part on a machine as compared to the mounting conditions used for part measurement. Once removed, the fixture induced stresses and the part’s internal residual stresses relax and change the shape of the generally thin parts machined in these applications. Thereby, the offline inspection provides an erroneous description of the performance of the machine. This research explores the use of a single, high resolution, capacitance sensor to quickly and qualitatively measure the low to mid spatial frequencies on the workpiece surface, while it is mounted in a fixture on a standard ultraprecision single point diamond turning machine after a standard facing operation. Following initial testing, a strong qualitative correlation exists between the surface profiling on a standard offline system and this online measuring system. Despite environmental effects and the effects of the machine on the measurement system, the capacitive system with some modifications and awareness of its measurement method is a viable option for measuring mid to low spatial frequencies on a workpiece surface mounted on an ultraprecision machine with a resolution of 1nm with an error band of ±5nm with a 20kHz bandwidth. / Thesis / Master of Applied Science (MASc)

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