• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 29
  • 10
  • 6
  • 5
  • 1
  • 1
  • 1
  • Tagged with
  • 56
  • 56
  • 28
  • 27
  • 25
  • 23
  • 23
  • 21
  • 17
  • 16
  • 16
  • 13
  • 12
  • 11
  • 11
  • 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.
21

Tříválcový vznětový motor pro užitková vozidla / Three cylinder diesel engine for commercial vehicles

Briš, Tomáš January 2017 (has links)
The diploma thesis deals with a design of a crankshaft for a three-cylinder diesel engine for commercial vehicles. The engine is a member of a unified line of engines with the number of cylinders from two to six. The main points of the work are a draft of the crankshaft configuration, the balance of inertial forces and the moments in the crank mechanism, creation of drawings of the crankshaft and finally carrying out a strength analysis of the part, taking into account torsional vibration. The aim is formation of a part – crankshaft for potential usage in the automotive industry.
22

Dvouválcový čtyřdobý plochý zážehový motor / Two-cylinder four stroke spark ignition flat engine

Dragoun, Jan January 2012 (has links)
This thesis deals with the possibilities for realization of the crankshaft-cylinder four-stroke gasoline engine is flat, usable in the urban vehicle. In the work described stresses exerted on the crank mechanism can balance the crankshaft, torsional stress and strength calculation method of control. In the final part of this work is outlined proposal for implementation of the crankshaft.
23

Hnací ústrojí osmiválcového leteckého motoru / Powertrain design of a eight-cylinder aircraft engine

Ošmera, Petr January 2008 (has links)
Configuration of the powertrain of a flat-eight engine with ordered basic parameters is the theme of this thesis which name is Powertrain design of an eight-cylinder aircraft engine. This thesis occupies with configuration design of the crank mechanism and firing order, balancing of centrifugal and reciprocating forces and their moments, conceptual design of crankshaft and its stress calculation. This thesis also puts mind to calculation of torsional vibrations.
24

Hnací ústrojí desetiválcového leteckého motoru / Powertrain design of a ten-cylinder aircraft engine

Kopřiva, Martin January 2008 (has links)
Configuration of the powertrain of a flat-engine with ordered basic parameters is the theme of this final thesis which name is Powertrain design of ten-cylinder aircraft engine. This thesis is occupied with configuration design of the crank mechanism and firing order, balancing of centrifugal and reciprocating forces thein moments, conceptual design crankshaft and its stress calculation of torsional vibrations.
25

Hnací ústrojí čtyřválcového leteckého motoru / Powertrain design of a four-cylinder aircraft engine

Příborský, Vladimír January 2008 (has links)
This thesis named Powertrain of an four-cylinder aircraft engine dealing with configuration of the powertrain of a flat four-cylinder engine with ordered basic parameters. The thesis is focused on configuration design of the crank machanism and sequence ignition, balancing of centrifugal and reciprocating forces and their moment, conceptual design of crankshaft and its stress calculation. The thesis describing calculation of torsional vibration as well.
26

Hnací ústrojí nekonvenčního vidlicového vznětového šestiválce s pryžovým tlumičem / Powertrain of unconvential V-6 diesel engine with rubber damper

Bečka, Petr January 2011 (has links)
The aim of this work is to design the crankshaft fork unconventional six-cylinder with offset pivots, the torque balance, modal analysis, vibration analysis of torsional and torsional vibration damper design, stress analysis using FEM.
27

Hnací ústrojí nekonvenčního vidlicového vznětového šestiválce s viskózním tlumičem / Powertrain of unconvential V-6 diesel engine with viscous type damper

Hejda, Tomáš January 2011 (has links)
The purpose of this thesis is design an unconventional powertrain V-6 engine with cylinder opening lines offset 90 degrees and 30 degrees of crank pin offset. It is an analysis of the balance of the crank mechanism, proposed unbalance, build a model of discrete torsion system, design of viscous torsional vibration damper, compares the results of the calculation of strength without crankshaft damper and with damper.
28

Dvouválcový čtyřdobý plochý zážehový motor / Two-cylinder four stroke spark ignition flat engine

Dragoun, Jan January 2012 (has links)
This thesis deals with the possibilities for realization of the crankshaft-cylinder four-stroke gasoline engine is flat, usable in the urban vehicle. In the work described stresses exerted on the crank mechanism can balance the crankshaft, torsional stress and strength calculation method of control. In the final part of this work is outlined proposal for implementation of the crankshaft.
29

Dvouválcový řadový vznětový motor s excentrickým klikovým mechanismem pro užitková vozidla / Two-cylinder inline diesel engine with an eccentric crank for commercial vehicles

Černohous, Tomáš January 2015 (has links)
The goal of this master’s thesis is to examine the influence of eccentricity on the behaviour of forces between the piston and cylinder liner and on balancing of the crank mechanism for given parameters of the diesel engine. Another aim of this paper is to propose an appropriate balancing of the crank mechanism followed by stress analysis considering torsional vibration for a chosen value of eccentricity.
30

[en] TORSIONAL FRICTION-INDUCED VIBRATIONS IN SLENDER ROTATING STRUCTURES / [pt] VIBRAÇÕES TORCIONAIS INDUZIDAS POR ATRITO EM ESTRUTURAS ESBELTAS

INGRID PIRES MACEDO OLIVEIRA DOS SANTOS 20 September 2019 (has links)
[pt] A vibração excessiva da coluna de perfuração leva à perda da eficácia do processo de perfuração de poços de petróleo e causa danos prematuros ao equipamento. Portanto, entender a dinâmica do sistema é essencial. O comportamento complexo das colunas de perfuração estimulou um grande número de publicações sobre a dinâmica de perfuração. A vibração torsional está presente na maioria dos processos de perfuração, eventualmente atingindo o fenômeno de stick-slip. Essa vibração torsional resulta da interação não linear entre brocas e rochas. Apesar da complexidade da interação broca-rocha, a relação entre torque e velocidade de broca é, frequentemente, tratada como uma força de atrito seco em um sistema delgado. Um grande número de modelos de atrito é usado para descrever a interação entre brocas e rochas, embora um modelo adequado seja necessário para uma interpretação precisa de sistemas com atrito. Esta contribuição utiliza dados experimentais de uma bancada de testes, capaz de reproduzir o comportamento torsional de um sistema real, equipada com dispositivos de freio simples para introduzir atrito ao sistema, perturbando o movimento de rotação. A bancada é matematicamente modelada como um pêndulo de torção atuado. Esta dissertação propõe um modelo de atrito baseado em dados experimentais e analisa vários fenômenos observados em relação ao atrito, incluindo a histerese. Os resultados experimentais são usados para identificação dos parâmetros do modelo proposto. Por fim, simulações numéricas e resultados experimentais são comparados para validação do modelo de atrito proposto. / [en] Excessive drill string vibration leads to loss of the drilling process effectiveness and premature damage to the equipment. Therefore, understanding the system dynamics is essential. The complex behavior of drill strings attracted considerable attention in specialized literature. Due to the drill string slenderness, torsional vibration is present in most drilling routines, eventually reaching the stick-slip phenomenon. This torsional vibration results from the nonlinear interaction between drill-bits and rocks. Despite the complexity of the bit-rock interaction, researchers often treat the relationship between torque and bit velocity as a dry friction force in a slender system. A large number of dry friction models is used to describe the interaction between drill bits and rocks although a proper model is required for a precise interpretation of systems with friction. This contribution utilizes data from a test rig that is capable of reproducing full-scale system torsional behavior with simple brake devices to introduce friction into the system, disturbing the rotating motion. This test rig is modeled as an actuated torsional pendulum for the numerical investigations of the experimental friction. This dissertation proposes a friction model based on experimental data and analyzes various frictional phenomena observed, including hysteresis. The experimental results are used to identify the proposed model parameters. Lastly, it compares numerical simulations with the experimental results and validates the proposed friction model.

Page generated in 0.0921 seconds