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Über dieses Buch

This book is based on the 55th International Conference of Machine Design Departments 2014 (ICMD 2014) which was hosted by the Czech Technical University in September 2014. It features scientific articles which solve progressive themes from the field of machine design. The book addresses a broad range of themes including tribology, hydraulics, materials science, product innovation and experimental methods. It presents the latest interdisciplinary high-tech work. People with an interest in the latest research results in the field of machine design and manufacturing engineering will value this book with contributions of leading academic scientists and experts from all around the world.

Inhaltsverzeichnis

Frontmatter

Machine Design

Frontmatter

A New Stand for Fatigue Testing of Pillars

A new stand for fatigue testing was designed. This stand allows testing six pillars in the same time. This contribution deals with design of stand and with influence between pillars.

L. Barton

HCR Gears in the Industrial Gearbox

Gearing with a prolonged contact ratio – so called HCR gearing is used more and more in these days, mainly for the gearboxes in the automobile industry, and for other transport machines. HCR gearing mainly influences the noise reduction in the gearing system. Relative addendum of the HCR gearing usually changes the height of the gear ha∗ $$ {\mathrm{h}}_{\mathrm{a}}^{*} $$ , however, this value must be higher than ha∗>1 $$ {\mathrm{h}}_a^{\ast }>1 $$ .

M. Burián, M. Trochta, J. Havlik

Design of the Vibration Separatory Apparatus

Stabilization/solidification is used for liquid waste processing. For the purpose of liquid and solid phase separation the experimental vibration separatory apparatus is designed. It can be used with common cement mixer and easily transported by means of the car trailer. The device is equipped with vibration motor and it is designed as hand-operated.

M. Dub, S. Sadek, J. Hendrych, P. Spacek

Designing of Mixing Equipment, Reactors and Bioreactors

The present work deals with general description of the most common processes in the agitated batch (blending and particle suspension) and with hydrodynamic parameters and geometrical configuration of the mixing equipment (shape of vessel, baffle and impeller and their mutual arrangement) that influence the process. The optimization of the construction and arrangement of the mixing equipment were performed to ensure the specified process with minimum energy consumption.

T. Jirout, D. Jiroutova

Modern Trends in the Drive Wheelsets of Rail Vehicles

The paper describes trends in individual wheelset drive and drives of independently rotating wheels of modern low-floor trams and rail vehicles. It documents the way of constructive design of individual wheelset drive (without gear box) and wheelset drive with gear boxes.

J. Kolar

Scale-Up of Equipment for Thermal-Expansionary Pretreatment of Lignocelluloses

Thermal-expansionary treatment is a novel environmentally friendly technology that has a very high potential to be installed in various industrial biofuel technologies as a preliminary step of biomass processing. Several industrial batch apparatuses have been worldwide installed yet but there is still problem how to do it in continuous mode. Suitable process parameters (process temperature, residence time, biomass concentration) are able to be easily determined in laboratory scale. Based on these process data, this paper is dedicated to develop the methodology, how to transfer suitable process parameters to industrial scale, to present industrial basic equipment design and to solve the problematic of continual batch decompression into storage vessel.

L. Kratky

Should We Teach Polymeric Machine Elements as Well?

The growing importance and use of polymeric (plastic) parts in many industrial product categories isn’t generally accompanied by adequate education at the university level. In response, an overview of relevant literature on polymeric machine elements is presented. Most important differences in characteristics of the polymeric and metallic materials are also highlighted, and the contents of a Croatian textbook on polymeric machine elements are used as a reference.

B. Križan

Design of Semi-active Magnetorheological Valve

This paper presents a methodology of design of a semi-active magnetorheological (MR) valve. The MR valve has been used successfully for a long period of time in many technical applications. When the valve is used as a semi-active element, problems occurred. The application of this valve is limited, mainly due to the slow response time and its low dynamic range. The methodology consists of flow analysis of a non-Newtonian fluid and FEM analysis of a magnetic circuit. A parallel-plate model was used together with Bingham fluid to describe the flow in the valve. A static and transient model of the magnetic circuit was solved by the FEM program Maxwell. The semi-active MR valve design was based on the presented methodology. In our research the magnetic circuit was made from ferrite that significantly reduces the response time of the magnetic field. The valve was designed only to operate only until the velocity at the breaking point of the F-v curve. Therefore, now there is a large dynamic range in this area. It is reasonable to expect that the designed modifications of the MR valve allow us to use this technology in semi-active suspension systems.

M. Kubík, I. Mazůrek

Support Tools in the Development of Bearings for Wind Turbines

The aim of this paper was to show the way to build a model roller bearings in the program execution Adams for dynamic analysis and obtain information about different parts of the bearing during the simulation. Bearing model was designed to be as close as possible to the actual deposit, which allows us to get an idea of traffic load, the dynamic conditions of the bearing parts and interactions between them. And in the second part describes the preparation of a prototype designed for durability tests.

R. Madaj, R. Kohar

Note to an Undercut Limit of Involute Gearing

An undercut of an involute tooth flank is a routine matter. Moreover there is no need to be concerned with an undercut if there is no problem with teeth strength. A problem occurs if undercutting strikes not only a root but an involute flank too. It even does not matter until an operational part of an involute is not cut off. In this case the size of decreasing of a transverse ratio coefficient εα is necessary to specify. This contribution deals with two approaches to the determination of start of undercut involute and performs their evaluation with possible implications. At the conclusion the contribution is highlighting to one unpublished fact.

M. Nemecek

Assessment of Industrial Design Projects with Use of Online Evaluation System

During study of Industrial design, students create multiple projects, which are always evaluated in terms of aesthetic value and are assessed afterwards with a grade. Since perception of such designs is a subjective, objectivity can’t be achieved by single teacher. The paper analyses current methods of assessing de-sign projects and examines their application in online evaluation system, which is used during education. Method for assessing projects is based on multiple evaluations by teachers. Relationship between ordinary and online assessment are studied and described.

M. Ondra, R. Machalek, D. Skaroupka, D. Semrad, F. Uhlir

Vibration Isolation Pneumatic System with a Throttle Valve

The paper shows a possibility of the tuning mechanical system by means of two pneumatic springs in a differential configuration connected with a throttle valve. The springs are inserted into the lead mechanism and connected to its parts, and to its supporting platform. The vibrations, transferred from the kinematic excitation of the base, are intended to be minimized. The vibration isolation by means of pneumatic springs is available in many technical systems, e.g. in supports of heavy machinery as well as in systems characterized by the human interaction, such as driver seats, ambulance couchettes, etc. The pneumatic springs provide the option of adaption of the stiffness, and herewith the adaption of the natural frequency of the system according to the exciting frequency. In cases of application of the object vibration isolation, they can change the load characteristics in a relative large range. In the studied case of the differential spring configuration, the springs are connected with an air pipe to the throttle valve. The air being exchanged during the motion period comes through the valve, the cross-section of which determines the time delay of the pneumatic sub-system thus creating a hysteresis of load characteristic of the spring support. This brings an additional, controllable damping to such a system that is profitable in most vibration isolation cases.

L. Pesik, A. Skarolek, O. Kohl

Development of the Assembly Set for the Logistic Transport Solution

Reconfigurability has become as a new engineering technology which has a significantly impact on the changes in design. Reconfigurable manufacturing systems should be designed so that they can effectively respond to changes in the product requirements. Currently reconfigurable products will be a great benefit for customers and also a big challenge for designers of the manufacturing systems.

R. Sásik, M. Haluška, R. Madaj, M. Gregor, P. Grznár

The Design of the Device for the Manufacture of Planar Filter

The contribution describes a device for folding flat filter masks civil protection with nano fiber layer. This layer is in a protective case and requires special treatment. The aim of the research was the development of a new type provided that the production of the filter will be large series. Activity in the folding machine must be in controlled mode, without human intervention. The main problem is the mechanical rigidity of the needles that are control by pneumatic system. These needles are essential for equal foundation fabric. In this paper will be made the strength check by FEM. Was checked deformation and stress of the needles. They were designed structural measures to ensure the function of the mechanism.

L. Sevcik

The Structural Design of Industrial Vacuum Cleaner for Dental Laboratories

Developed industrial vacuum cleaner, is designed for use in dental laboratories. Primarily is the vacuum cleaner designed for suction of fine dust generated during the manufacture of dental prostheses. In the medical field in general, emphasis is placed on quality workmanship, durability and cleanliness of the environment. This represented a challenge in the design of the device with respect to the required performance and price. Compared with similar vacuum cleaners on the market, with the same power, there is a much better ratio of the basket volume, to the overall dimensions of the vacuum cleaner. The hallmark of the vacuum cleaner is the ability to connect two separate hoses to the vacuum cleaner. Unique about the vacuum cleaner is a triple filtration system and noise, which is lower than competitors. This article describes the development of the vacuum cleaner.

R. Slanina, P. Sniehotta

Reading of Operating Values of End Effector During Goods Manipulation

The article describes methodology of reading of operating values of end effector during goods manipulation. Among read values will be gripping force of end effector jaws, amount of grip distance and weight of manipulated goods. In case of right forming of mathematical model of the end effector, the software should be able to determine actual position of manipulated goods with consideration of acceleration influence.

F. Stary, V. Dynybyl, J. Mrazek

Building Platform for Identification of Important Parameters for 3D Printing of Huge Parts

3D printing of big and very big parts is used mostly in mechanical engineering, automotive industry and industrial design. 3D printing can be used to manufacture prototypes of complicated shapes, which could not be manufactured using different technologies and it is not needed to manufacture expansive tools. To be able to print enormous parts with FDM technology many obstacles must be overcome and several unknown parameters have to be revealed. Primary focus of research and development in this paper is description of building process of experimental device, which will be used to identify important parameters of printing process of huge parts. Some and most important of these parameters are supposed to be influence of scanning speed as well as speed of filament movement and influence of melting temperature. Very important issue to observe and take care of is thermal stress inside the printed material and of course final strength of the part. We assume that we will be able to show experimentally that all of these parameters are important and influence the final part quality.

M. Suransky, M. Zlebek

On Cardan Joint: Some Special Applications

Cardan joint (Gerolamo Cardano 1501–1576) is one of the scientific results of the renaissance scientist (mathematics, astronomy, astrology, philosophy). At present time is this one applied as mechanical joint which allows the transport of the torsion moment between intersecting axes. It is known that this transport is dependent on the angle between both axes. In this contribution it will be described some other applications for example in the metrology and experiments with redundant kinematics system.

J. Zicha, K. Macuchova

Tribology

Frontmatter

Experimental Analysis of Tribological Properties of Heat Treated Graphitic Cast Irons

The results of research investigations of tribological properties of heat-treated cast iron with globular graphite are presented. The samples of investigated materials, including the reference material steel C45 were heat treated to the same hardness value. Tests were carried out on the experimental device with a linear reciprocal movement with variable speed using the Ball on Plate method. The device simulates real changed conditions in different environments of the tested contact pairs, such as sliding bearing, hinges, brackets and the like. The results of measured tribological properties of materials show that for practical applications and for specific environments and dynamic conditions the replacement of the original material C45 by isothermally tempered cast iron may be realistic.

J. Broncek, P. Fabian, M. Dzimko, N. Radek

The Experimental Determination of the Grease Amount to Effective Wear Reduction in the Wheel-Rail Contact

The wear mechanisms within the wheel flange and rail gauge contact affect safety and operating costs of railway transport. This contact occurs when a rail vehicle reaches a curved track. A low coefficient of friction (COF) is required. This COF and wear rate are influenced by operating conditions (load, velocity and temperature), lubrication and geometry (i.e. the track curvature radius). The damage to the contact surfaces can be decreased by using on-board lubrication systems. Grease is applied to the first wheelset of a driving car by a nozzle. The rate of wear reduction depends on the grease amount and its application intervals introduced by the on-board lubrication system into the contact. In this paper, the full-scale laboratory apparatus has been used to study friction, wear and lubricant film distribution under pure sliding conditions in the wheel flange contact. The grease amount and its appropriate application intervals were found.

J. Fryza, M. Omasta

The Effect of Friction Modifier on the Wheel-Rail Contact

One of the key factors affecting the rolling-sliding contact is traction, which is expressed by the adhesion coefficient. It is a major characteristic for safety, efficiency, reliability and maintenance costs of rail transportation. The adhesion is influenced by many factors such as contaminants, environmental and operating conditions. The friction modifier (FM) is applied on the top of rail in order to control the adhesion coefficient in required range (0.3–0.35). This range is often called an intermediate level of friction. This study has two aims. The first aim is to introduce tribological aspects of FM. The second aim is to investigate the influence of the FM on the adhesion coefficient. The experiments were carried out on the ball-on-disc apparatus.

R. Galas, M. Omasta

Measurement Methodology of Low-Shear Viscosity of Reference Liquid Under High-Pressure

Accurate value of low shear viscosity under high pressure is important for predicting film thickness in elastohydrodynamic lubrication. This can be obtained theoretically from numerical simulations or by experiments on viscometers. Calibration of the viscometer has significant importance for precision. For this purpose, reference liquids such as squalane are used. Viscosity of these liquids can be easily compared with results published by other authors. In this work, methodology of measurement with the falling-body type viscometer with optical detection of falling-body speed is described.

S. Hornak

Modification of Tooth Flank as the Possibility of Increasing Resistance of Gearing to Pitting

In this article are shown the influence of the tooth flank to reduce damage to the working tooth flanks in terms of the pitting. The introduction of the article describes a fundamental difference between the involute and noninvolute gearing and the influence of some parameters, especially of the slip ratio to damage of gearing. The paper also shows the basic results of the experiment, which was executed on two types of gearing (HCR gearing and C-C gearing) on the Niemann’s stend in term of the damage to pitting [1].

B. Kopilakova, M. Bosansky, J. Zapotocny

Including the Method of Lubricant Film Thickness Measurement with the Use of the Monochromatic Interferometry to the Education of Tribology

Measuring of distance as presented at the universities is usually limited to dimension down to microns. This orders of distance are sufficient for common engineer’s application. However dimension are a lot smaller when engineers deal with the tribology research. One of the most important progresses in the field of tribology in last century is without doubts the elastohydrodynamic lubrication (EHL). This lubrication regime can be found for example in rolling bearings or gears. Common thickness of the lubricant film in the EHD contact is in order of tens or hundreds of nanometers. Optical method which enables measurements of such distances was developed by Gohar and Cameron in 1960s. This method is based on interference of monochromatic light and provides possibility of obtaining lubricant film thickness from known wavelength of used light and its intensity in the lubricated contact. Students can create central film thickness prediction with use of the analytical formulae of the Hamrock and Dowson. This prediction is then confirmed by hands-on experiment in laboratory. Contact simulator with microscope and red light is used to record sequence of the interferograms. These interferograms are then processed in Matlab® software in order to obtain film thickness.

D. Kostal, I. Křupka, M. Hartl

Frictional Properties of PVA Hydrogel

Total hip replacement is one of the most successful surgical treatments of modern medicine. Typically, at present, hard-on-hard bearing surfaces are widely used for components of artificial hip joints. Hard-on-hard means that both components have high modulus of elasticity in range of hundreds of GPa. However, these materials suffer from relatively high friction and wear rate. This is connected especially with occurring lubrication regime. To approach conditions presented in natural joints, it is necessary to think about artificial cartilage. One of the anticipated materials for artificial cartilage is polyvinyl alcohol (PVA) hydrogel. PVA hydrogel has water content about 85 % and its elastic modulus is approximately E ≈ 1.2 MPa, which is similar to natural cartilage. The main disadvantage of PVA hydrogel is its lower strength. In this study, commercial mini traction machine (MTM) was used to determine friction coefficient for various slide-to-roll ratios (SRR). Bovine serum was used as a lubricant and the tests were carried out under ambient temperature for three various speeds u1 = 25 mm/s; u2 = 50 mm/s; u3 = 100 mm/s and two different loads F1 = 5.2 N; F2 = 9.8 N, respectively. As expected, friction coefficient was very low, less than 0.05 under some conditions. In future, optical method based on the principle of fluorescent microscopy will be used for studying lubricant film thickness and protein adsorption on bearing surfaces.

D. Nečas, M. Vrbka, S. Yarimitsu, K. Nakashima, Y. Sawae, P. Šperka, I. Křupka, M. Hartl

Effect of Sanding on Adhesion Under Oil and Water Condition Between Wheel and Rail

Adhesion in contact between wheel and rail is significant process in railway systems. Adhesion is affected by many factors such as speed, load and especially contaminants like leaves, water, oil, dust and other. Contaminants can decrease adhesion to very low adhesion and can causes serious problems such as extended stopping distances, or, in traction, it may lead to time delay of train. Sand has been usually used for effective increase of adhesion, but its disadvantage is abrasive effect on wheel and rail. A systematic laboratory investigation of the effect of sanding on wheel and rail has been performed using twin disk simulation facility, which consists of disk simulation of wheel and disk simulation of rail. Discs have equal diameters, due to simulating equivalent contact zone different geometry compared to real conditions. The results show that sand increases of adhesion coefficient enough in water and oil contaminated contact. Wet leaves rapidly drop adhesion coefficient, sand in this condition enhances adhesion less because of the presence of steady layer of leaves. Sand has problem to break this layer and effectively decrease adhesion coefficient.

D. Smejkal

Hydraulics – Fluid Mechanisms

Frontmatter

Experimental Research and Optimization of Characteristic Parameters of the Valve Plate of the Axial Piston Pump/Motor

Modern design of the axial piston pump/motor, based on computer aided design, requires description of all processes and parameters in the pump/motor. The hydrodynamic and dynamic processes in the axial piston pump (cylinder, intake and discharge chambers, discharge valve, and high pressure pipeline) are very complex, so they demand a thorough physical and mathematical analysis. Compression losses, which are caused by sudden pressure changes in the cylinders of cylinder block, result in energy loss and increased noise. The compression losses can be decreased by identification of optimal dimensions and shapes of the port at the valve plate.

R. Petrovic, M. Andjelkovic, M. Radosavljevic, N. Todic

The Effects of the Temperatures on the Performance of the Gas Turbine

The parametric study of thermodynamic performance on gas power plant. The variation of operating conditions, exhaust temperature. Gas turbine inlet air cooling has been considered for the power output and efficiency of gas turbine during hot seasons. In this research, the power requirements of several inlet air cooling techniques for gas turbine power plant. The considered techniques are evaporative cooling and chiller coils system for decrease the inlet air temperature to the compressor. The results show that the inlet air temperature, compressor ratio, inlet gas turbine temperature are.

A. Wahab, T. Ibrahim

Engineering Analyses

Frontmatter

Innovation of Methodological Support of Risk Analyses of Technical Products in Their Life Cycle During Their Designing

Concept of enhanced methodological support of risk analyses of technical products looked upon technical systems (TS) in the context of their Life Cycle (LC) is described in this paper. Within the methodological framework for innovation of risk analyses well proven method FMEA was used. The mentioned innovation of methodology consists of increasing of its complexity, systematic and also of increasing of its flexibility by application of key knowledge of Engineering Design Science, mainly from the Theory of Technical systems (TTS). The proposed methodology was verified and validated on specific example from industrial practice.

J. Dvorak, M. Sasiadek, S. Hosnedl

The Mathematical Description of Sunflower Seed’s Hulling Process Using Impact Huller

This work aims to describe mathematical model of Sunflower Seed’s Hulling process. Exactly, the movement of sunflower seeds inside rotor is described by equations of motion as a function of time.

J. Hoidekr, J. Andrus, V. Dynybyl

Roller Bearing Fatigue Life Calculation with Inclusion of the Fits Parameters

This article highlights the possibility of including the effect of fits on the accurate calculation of the fatigue life of rolling bearings and limits of ISO 281, which provides the calculation of service life for over 60 years.

S. Hrcek, R. Kohar

Application of Statistical Methods to Analysis of Parallel Structure of Gearbox Test Rig

Paper presents usage of statistical methods for an analysis of run of parallel structure. There was reported a problem that actuators of vertical axis are not uniformly loaded. Variance of acceleration record from each actuator were analysed and compared. There was performed normality test with Chi-Square. To compare the variance of acceleration there was used a non-parametric Kruskal–Wallis test. To identify a problematic actuator there was used a multiple comparison test and matrix of correlation coefficients with graphic output was constructed. The analysis pointed out on the most problematic actuator. Gathered information was used for further optimization and improvement of structure.

J. Chmelar, K. Petr, V. Dynybyl

Driving Shaft Fracture Analysis

The article deals with the determination of the causes of failure of the driving shaft of the conveyor belt. The detection of the causes of this damage is based on the appearance of the shaft fatigue fracture and subsequent fracture surface analysis, the calculation of the stress for actual load and information about the belt operation.

K. Kaláb

Force Conditions at an Antibacklash Designed Gear Mechanism

The paper contains a description of one of principles of the backlash-free transmissions. Specially is resolved design of the zero-backlash gearing with countershafts. The backlash elimination in gears and bearings is obtained by the preloaded torsion-bar spring. There is determined dependence of reaction forces, acting on gears and bearings, to magnitude of the torsion-bar spring preload. Using the computer program, created in the Maple environment, is simulated running of loaded gear with reversation of rotating direction. The outcomes are used for control of strength, fatigue of material and service life of gearing.

V. Kloucek

The Effect of Fits Stiffness on Distribution of Internal Loading in Rolling Bearings

This article discusses the effect of fits stiffness on distribution of internal loading in rolling bearings. Investigating effect of stiffness was performed by using the finite element method, because with the analytic method, this effect is impossible to include in the load distribution calculations on body parts, which transmit load in rolling bearings.

R. Kohar, S. Hrcek

Design Calculation of Spur Gear Module

Spur gearset has been designed and verified using three software programs and an analytical approach. The programs used in the experiment included Inventor, KISSsoft and MITCalc. By comparing the outcomes achieved with identical input data, one can assess the suitability and potential of the software programs for industrial and educational uses.

E. Kronerova

Application of the Bond Graphs to the Description of Technical Systems

The basic information about bonds graphs is summarized. Basic models of components used in the description of technical systems with bonds graphs are characterized. Selected elements of mechanical and energy are described with bonds graphs. Discussion on the nature of the diagnostic parameters described by graphs is conducted. The analysis of bonds graphs suitability as a source of diagnostic information is made. Ways to use the information provided by bonds graphs, especially for mechanical power generation equipment and their components, are suggested.

Z. Matuszak

Assessment of the Validity of Technical Elements of the Complex Structure Using Flow Streams of Energy Factors

In this paper have been characterized, reported in literature, the validity of measurement items (measures Birnbaum, the potential of improving the reliability, Lambert, …), mainly relating to the related concepts with more reliability and structures of the more reliability. In this paper, an analysis of the direction and amount of flow streams of energy factors in the systems. The analysis will be performed for the so-called. dynamic functional structures. These are the structures in which during operation. These are the structures in which during operation occurs change the direction of flow of streams of energy factors and the changing number of streams of energy factors and the number of working components. On the basis of these changes can extract the individual states of the system. For particular operating conditions shall be tables streams flow of energy factors for functional structure of the system. The validity and importance of the element in the system is evaluated based on the number of streams of energy factors and leave the water runs out of the item. The greater the number of these streams, the element is more responsible for the operation of the system in a given state.

Z. Matuszak

Influence of Short-Circuit Valve on Hydraulic Recovery of Vehicle Kinetic Energy

The present paper deals with one of possibilities how to improve the efficiency of recovery processes using the experimental road roller AMMANN AP 240 H. The recovery of braking kinetic energy can significantly contribute to fuel consumption lowering of heavy horse vehicles working in start-stop regime. The paper presents and evaluates the results of parallel measurements performed on the experimental vehicle.

Z. Nemec, J. Nevrly

FEM Simulations on Gears with Different Carbonized Depth

The article describes the possibilities of increasing of the load capacity of gearing by optimizing thickness of the surface layer of case-hardened tooth flanks, which have different thicknesses and pressure angles. Further is described the creation of FEM (finite element method) simulation model of gear-mesh with the application of various surface layers and then are described calculation results. Mechanical properties of the surface layers are determined from the material analysis.

K. Petr, V. Dynybyl, J. Krepela

Numerical Simulation of Ductile Fracture

Brief introduction into ductile fracture material models based on damage mechanics approach suitable for FE simulation is given in the article following with two examples of calibration. The first example introduces calibration of steel commonly used in nuclear power plant industry that was based on wide portfolio of 15 experimental specimens. The second one deals with simplified calibration of armor steel based on shooting tests.

M. Spaniel

Dynamic of Propulsion, New Challenges for Analysis

Every propulsion system, especially when it contains piston machines, or engines, or compressors, needs already in project phase an analysis of propulsion dynamic to avoid serious problems or damages in operation. A basic part of such analysis is a torsional vibration calculation. Methods for such calculation are nowadays quite good known und used. Development of programs for these calculations concerns improvement of their user-friendliness. But development of modern propulsions, where new types of machines and more sophisticated control systems are used, brings new aspects which need to be respected. Some of these aspects are described in this paper.

V. Zoul

Modern Material and Technology

Frontmatter

Corrosion in Some Iron Alloys

This work contains many investigations to estimate the corrosion behavior of iron alloys such as (BC18, BC13, 25CrMo4) during exposure to inorganic acids (Hcl─HNO3─H2SO4) and (NaOH). Chemical compositions of allays were analyzed by spectrometer type (ARL), in weight percent. Many heat treatments were done to show their effects on corrosion resistance. Investigated specimens in disc form were immersed in aggressive mentioned solutions, for defined times. The lost in weight of specimens due to corrosion were removed manually and registered. The corrosion rates (g/m2ċh) were calculated according the Eq. (2) referred to in the text, during exposure time of (120) h and (240) h for some alloys. This enables the conclusion that alloys with Cr% more than 12 % had more corrosion resistance than others. Also heat treatment improved corrosion resistance, and that solution of the acids was the most aggressive medium.

M. Khidhair, M. Hasan

Overview on the Clinched Joint Method

This article aims to give the general overview of the recent state in the problematic of joining thin-walled products. Clinched joint represents one of the technologies that are used for connecting sheet-metal parts into a final assembly. Characterization of the technology, different types and possible application of the joints are also introduced in the text.

P. Maly, V. Dynybyl, J. Sojka, F. Lopot

The Process of Preparation Prototypes Bearing Cages for the Durability Testing

The aim of the article is to introduce readers to the topic of using modern technologies in prototyping, including the technology of vacuum casting. This article further describes a proposal of a special device that would be used for rapid prototyping of bearing cages, which would subsequently be a subject to a durability test.

P. Spišák, R. Madaj

Optimization and Design

Frontmatter

Optimisation of the Geometric Design Parameters of a Five Speed Gearbox for an Automotive Transmission

Optimisation of the geometric design parameters of a five speed gearbox for an automotive transmission is studied. The bending stress is considered as the objective function, and the design parameters are optimised under several constraints, including contact stress and constant distance between gear centres. During optimisation, the contact ratio changes with respect to pressure angle, and the effects of the contact ratio and profile modification on tooth bending stress are analysed. By optimising the geometric design parameters of a gearbox, including the module, number of teeth, helix angle and face width, it is possible to reduce tooth bending stress and obtain a light-weight-gearbox structures. It can be concluded that increasing the contact ratio results in a reduced tooth bending stress; however, in contrast, increasing the pressure angle caused a reduction in the contact ratio and an increase in tooth bending stress and contact stress. In addition, it can be concluded that positive profile modification reduces tooth bending stress. All of the geometric design parameters determined by optimisation satisfy all constraints.

M. Bozca

Modification of Experimental Station AXMAT

In this article is described modernization of experimental station AXMAT, which is used for testing of contact fatigue of small axial bearings and flat specimens. The test-rig is placed in a laboratory of Institute of Machine and Industrial Design of Brno University of Technology. Original setup of the test-rig was based on applying of axial force at a specimen by mechanical lever with additional weight. This stand is designed for determination of resistance of materials and bearings against the contact damage. This is achieved with use of vibrodiagnostic. Essential changes were made on the test-rig by its modification. A new hydraulic load system for set up of axial force on a specimen was developed. A control program was created in SIMULING for operating of the hydraulic system and its force. This program gives a chance to adjust applied axial force on a specimen in optional modes. Moreover a feedback for record of vibration, acoustic emission (AE) and temperature signals was created. An analysis of AE signal enables a detection of contact fatigue formation before pitting occurs. Due to that it is possible to detect defects on a specimen earlier than by standard vibrodiagnostic’s method. Because of a new modifications and improved measurement system the test-rig provides more complex and accurate detection of a contact fatigue.

J. Dvoracek, L. Komenda, L. Nohal

Basic Conditions of the Implementation of Extremal Regulation

Extremal regulation is an optimization method that does not require knowledge of mathematical model because it is practiced by experimentation on device directly in operation. The first part of this article contains brief characteristic of extremal regulation and presentation of controlling of torsional vibration at the system. The second part includes illustration of control algorithm of extremal regulation system at the implemented mobile torsionally oscillating mechanical system at steady state. The main aim of this article is to summarize the way of application of this method in torsionally oscillating mechanical systems with usage of pneumatic flexible shaft couplings being generated at our department.

J. Homišin, M. Moravič

Design of a Disc Grinder for EDM Electrodes Machining

This paper gives a review of possibilities for dressing rotational electrodes by electro discharge machining (EDM) technique. We designed a vertical EDM disc grinder as an alternative to available sacrificial block electrode dressing technique. We performed experimental machining tests with this vertical grinder and we have explained the effects, which affect the stability of this electro discharge machining technique.

J. Hosek, J. Drahokoupil

Optimized Design of the Wind Turbine’s Composite Blade to Flatten the Stress Distribution in the Mounting Areas

This paper presents the numerical method and results of the structural optimization of the wind turbine blade’s mounting zones to diminish and flatten the stress distribution at the action of the wind load on the blade. The blade, which has the stiff carbon/epoxy composite skin and less stiff lightweight core body, is mounted by two spokes to the rotor hub, and due to the wind load the areas of the blade near mounting of the spokes are extremely stressed. To minimize these stresses concentration the guess model of the blade was created using NX CAD tool, and finite element analysis was provided using COMSOL Multiphysics. Our modeling of the distributed air pressure load on the blade surfaces at the different wind orientation used the turbulent k-ε flow model, and allowed to find most loaded angular position of the blade at the rotor rotation. In order to minimize the peak von Mises stress around most stressed mounting hole the founded pressure field was imported to the Structural Mechanics/Optimization module, which solved the coupled mechanics/optimization problem. The optimized parts were the multilayered polymeric composite spacers with the hardened metallic folies and hole for the spoke fixing. As the design variables we used two parameters that describe the axial and radial dependencies of varied Young module and also the wall thickness of the spacer. The objective function was assumed in the form of the weighted sum of von Mises stress averaged over the area around the mounting holes. Finally we demonstrate some optimization results.

P. Oganesyan, I. Zhilyaev, S. Shevtsov, J.-K. Wu

Research of New Composites for Lightweight Construction with Low Impact on the Environment

New types of composite materials are currently very important for use in lightweight structures with very high strength and resistance to external influences. Therefore, it is increasingly used for their properties in all areas of industrial production. Their application offers a significant weight savings and reduction of a manufacturing energy consumption. But current composite properties are not at maximum level, thus development efforts are focused on their improvements. One of the problems of new composites is a study and description of an interface between the phases. The paper describes experimental and FEM analysis dealing with mechanical properties at the micro level. Analyses were focused on a cohesion and the strain at the interface of the system fiber-matrix-core. These composites are used for components of car parts such as doors, diffusers, spoilers and more detailed description can be applied for the improving of mechanical properties of composite structures.

M. Petrů, P. Lepsik, Ondřej Novák

System of Low Profile Roller Conveyors

The article describes design of modular low profile roller conveyor for pallet transport. The article compares tangential and chain to chain variant. Further describes modifications of roller conveyor to reduce price of conveyor.

F. Stary, V. Hanus

Fiber Driven Tilting Mechanism

The paper deals with the optimization of the experimental functional model of the fibre driven tilting mechanism with three degrees of freedom and four drives. Measured orientation of the platform is realized by means of incremental sensors in central joint. The optimization of the calibrability and the sensor placement shows, that the measurement of the platform position (orientation in the spherical case) is necessary both for the good calibrability and for its accurate position control.

P. Svatoš, Z. Šika, M. Valášek, J. Zicha, V. Bauma, V. Rada

Product Innovation

Frontmatter

Pneumatic Dual Mass Flywheel – Damper Concept for Downspeeding

Modern drivetrain, new types of engines and the effort to reduce the weight of the system improves the efficiency of powertrain. But also it is the way that the given system much more sensitive to the vibration. Today’s damper system, damped clutch disc and dual mass flywheel cannot remove or shift the resonance field from working area of engine in all cases which powertrain can have. Therefore we proposed a new type of the dual mass flywheel in the framework of our workplace in order to improve behaviour of powertrain in vibration field.

R. Grega, P. Baran

Rationalising the Use of Design for Assembly as DfX Knowledge to Increase Competitiveness of Designed Technical Products

Interdisciplinary Design for X knowledge and methods belong among powerful methodological ways for increasing effectiveness and efficiency of engineering design processes and consequently the competitiveness of the designed technical products. The letter X mostly indicates a specific property of technical products or more often their professionally related set. Such sets of knowledge and methods are then accordingly called for example: Design for Cost, Design for Assembly, Design for Safety etc. It is generally known that there are a lot of such DfX sets developed spontaneously including their names. A rational concept of a systematic taxonomy for DfX knowledge and methods is introduced in the paper. The core of this paper is focused on the general principles of DfX taxonomy and methodology applied on the Design for Assembly (DfA) field. This methodology is focused on reducing cost for assembly and curtailment assembly time of designed technical product while keeping its delivered quality. Validation of the introduced DfA methodology is presented on cases from industrial praxis.

S. Hosnedl, M. Kopecky, M. Sasiadek

Materials and Sustainable Development

This conference paper deals with ideas of sustainable development. How to introduce students to this? There is no completely “right” answer to questions of sustainable development, there is a thoughtful, well-researched response that recognizes the concerns of stakeholders, the conflicting priorities and the economic, legal and social aspects of technology as well as it environmental legacy.

I. Mazinova, M. Bochinsky

Experimental Methods and Measuring

Frontmatter

Design of Experiment for Load Gear Solution in Planetary Transmission

This paper is focused on examination of teeth loading in rotating gears during standard operation and describes the applied approach and device developed. One of the closely examined items in planetary transmission testing is the gearing. The tooth load of each wheel in planetary transmission is monitored individually. In large devices, also the load across the width of the tooth is assessed by the K coefficient.

O. Berka, F. Lopot, M. Dub

Investigation of Tram Gearbox Hinge Behaviour

During the operation of trams in cities the chassis are dynamically loaded through acceleration, deceleration, passage curves and evidently by the roughness of the rail track. These added dynamic loads can significantly increase wearing of the chassis components and tram drive. The aim of this analysis is the investigation of stress state and motions of gearbox hinge. For this purpose, strain gauges and optical system Qualisys is used. Special type of strain gauges arrangement for measuring tension and bend is designed. Acquired data are processed in software Matlab and in user interface of the Qualisys software.

M. Dub, J. Kolar, F. Lopot, V. Dynybyl, O. Berka

Mechanical Properties of Fasteners

The basic fasteners include bolts and nuts. These parts have a very wide range of applications not only in engineering but also in other related fields. With this type of connections we encounter at every step. Manufacturers and distributors of these components are required to guarantee the quality of goods sold. For this reason, they are forced to perform independent quality control by independent laboratories. Characteristic test of fittings include tensile, torsional (bolt) and the ability to disassemble (nut).

V. Fliegel, A. Lufinka, R. Martonka

Mathematical Description of Non-linear Mechanical Behaviour of Materials Under Compression Loading, Case Study: Spruce Bulk Wood Chips

This communication discusses the mathematical description of mechanical behaviour of bulk spruce wood chips under compression loading. The dependency between compressive force and deformation curve characteristic was fitted by reciprocal slope transformation (RST) and tangent curve (TC) methods. The mathematical model coefficients of both methods were respectively determined by the least squares method and Marquardt Levenberg approximation process, all applicable in MathCAD software. It is confirmed here that both methods can suitably be used for the illustration of deformation curve characteristic of bulk spruce wood chips.

D. Herak, A. Kabutey, R. Sigalingging

Influence of Steel Sheet Width on Bearing Capacity of Resistance Spot Welding

A research was focused on an evaluation of a influence of a steel sheet S235J0 width on bearing capacity of a resistance spot welding. Different widths 15, 30 and 45 mm of 1 mm thick sheet of the steel were the tested parameters. A change of the bearing capacity, a deformation and an angle of the deformation were evaluated.

P. Hrabe, M. Muller

Calculation of Fuel Consumption on the Vehicle Simulation Model

This paper describes the methodology for fuel consumption calculation on the vehicle simulation model with hydrostatic drive in the program MATLAB/Simulink. The consumed fuel quantity is calculated from the engine relative fuel consumption. This calculation is based on digital approximation of the map supplied by the engine producer. The amount of consumed fuel obtained on the simulation model is confronted with measurement on the real vehicle. The methodology of fuel consumption calculation will be used in the criterion function for the optimization kinetic energy recovery process.

M. Kobza

Identification of Parameters of Stiffness and Damping Based on the Amplitude Frequency Characteristics

This text deals with the determination of stiffness and damping parameters of a dynamic system. These parameters are determined mathematically from the amplitude-frequency characteristics. In practice, this method is applied to automobile seat, which is equipped with a system of air springs without dampers.

O. Kohl

Measurements of the Integral Characteristics of Twisted Flow Using a Five-Tube Pressure Probe

This document summarizes developments in the measurement of the integral characteristics of fans carried out at VZLÚ, a.s. in 2013–2015. This especially concerns the method of the measurement of fans without a stator stage, where the characteristics of the output flow do not satisfy the requirement of a steady axial flow, but fall within the area of a rotating 3D flow field.

J. Kuzel, M. Golda, M. Kral, M. Hraska

Method of Experimental Measurement of a Bucket in Laboratory Conditions

The paper deals with a method of measurement of a bucket. The bucket is an excavating component of the compact bucket wheel excavator K100 (by NOEN Inc.). The bucket wheel excavator is a machine for surface continuous mining. The tested bucket will be statically loaded and deformation of the bucket will be measured at defined spot. A stand was designed especially for this purpose.

P. Kribala, V. Dynybyl, J. Kricka

Biaxial Stress of the Textile Car Seat Cover Tested in a Climatic Chamber

Knowing the mechanical and deformation properties of textile materials plays a major role in determining quality of the final product. While exploitation textile as a seat cover, influence doesn’t have only tensile properties in one direction but also is transmitted to the adjacent yarns in the fabric. The role of a seat cover is not just to cover up the foam but also increase the rigidity of the seat cushion and have influence to a viscoelastic behaviour of the foams. In the vehicle there are also an important changes in microclimate conditions. Big fluctuations of temperature and local increasing of humidity at the same time. In order to assess the impacts all of this condition was executed an experiment for biaxial loading in a climatic chamber with variable temperature and humidity.

P. Kulhavý, N. Kovalova, R. Martonka, J. Petrik

Hexapod Control System Optimization

Hexapod is a new testing device for generation of six degrees of freedom movement in the Laboratory of applied mechanics. Its control system is built from National Instruments components and control application is created in the software LabVIEW. Using the real-time system to run this application requires special programming procedures because the precise timing of the control loop has to be observed. The hexapod motion control is based on its kinematic model. This model calculates the engine control signals according to the input required by motion information. Its output data files are used as input data for complex 3D motion control. Equations for the six basic motions (3-axis movement and 3-axis rotation) were obtained from the kinematic model, too. These equations are implemented directly in the control program for basic movement and rotation control. The control system, program design and program optimization are described in this paper.

A. Lufinka, R. Martonka

Integration of Light: A Way to Measure Spectral Characteristics

Measurement of spectral characteristics of various samples provides information about their chemical composition. Measurement of many samples is made difficult due to their scattering properties. Sometimes also the measured signal highly depends on the direction of test light reflection. Light integration and collection solves some of these difficulties and enables to get reliable data. Two sample use cases are presented to illustrate how light integrators may provide a solution.

K. Macuchova

The Equipment for Temperature Measurements Near a Gear Tooth Flank

This thesis deals with a design of equipment for measurements of temperature near the gear tooth flank. Temperature measurements are useful for understanding of processes occurring during gear operation. Measurements of temperature are necessary for application of other measuring systems (for example application of strain gauges). Temperature is parameter for application of right oil type too. The article describes choosing of temperature sensors and a method of data transport from the rotating shaft. Software for data transport and calibration is described here. The calibration of sensors is described too. Instruction for use are introduced in the text. The equipment for temperature measurements was tested on the little stand which was especially designed. The goal of this paper is design and testing of equipment for temperature measurements near a gear tooth flank.

M. Mazac, P. Herajn, M. Svoboda

Determination of Power Losses Based on the Measurement in Closed Loop Test Bench for Automotive Gearboxes

This article deals with estimation of power losses on the closed loop test stand dedicated for endurance tests of automotive gearboxes. This test bench has got two specific properties. Firstly, the gearbox is connected to the bench in the same manner as in the vehicle which means that the gearbox is rigidly connected with the bolts to the engine cast and this assembly is than hung using rubber mounts to the test rig frame. Second specific property of this test bench is that it can be used either for one- or more-load level tests. The main target of this contribution is to describe the power flow in the closed circuit which means to find out power losses of its all parts based on the measured load. The measurement will be done for both pretensioning mechanisms which means for manually operated worm gear as well as planetary unit. The magnitude of power losses will be evaluated for different revolutions, load levels and speed stages.

O. Milacek, G. Achtenova

Experimental Measurements and Development of Agricultural Trailer

Article describes partial section of complex development of agricultural trailer. Article is focused on measuring equipment. In the early stages of development of trailer, the laboratory measurements were performed to determine the calibration constants of sensors. In the next stage of development of trailer, the experimental measurements were performed in the real operating conditions. Based on the proposed methodology for measuring some parts of trailer were selected to monitor the load and deformation. The results of measurement were used for further analysis. Furthermore, comparison of results of FEM analysis and experimental measurement was made.

P. Mossoczy, R. Uhlir, P. Maly

Deformable Mirror for High Power Lasers

The deformable mirror under development is a prototype of a large aperture adaptive optics for high power lasers. Its bimorph and lightweight structure consists of a composite core, electrodes, a piezo-ceramic layer and a reflective layer. A double exposure method and a real time holographic interferometry method are used for measuring deformations of the mirror sample induced by the active layer. Various piezo materials have been tested for its suitability, namely their hysteresis.

S. Nemcova, J. Zicha

Identification of Failures of Technical Equipment Using Acoustic Camera

Article discusses the use of an acoustic camera for identification of noise sources in the technical equipment and identify sources of environmental noise. It is a device which can identify the sources of acoustic emission using a special microphone kit and it is possible to interpret the measured data graphically. Due to its composition, the application of acoustic camera to localize sound in various fields of human activity in the outer environment.

S. Poljak, I. Gajdac

Assessment of the Mechanical Properties the Polyurethane Foam Under Multiaxial Loading in a Different Climatic Conditions

Study of the mechanical properties of the polyurethane foams (such as comfortable filler of automobile seats) is important for a comprehensive understanding of the response of this nonlinear viscoelastic material. It is very essential for their comparison with other materials, because the current trend of development is pushing to find a new low-energy and low-density material. Two foams from the automobile seats with a different densities were assayed, under multiaxial loading for the several different climatic conditions.

P. Srb, P. Kulhavý, R. Martonka

Experimental Analysis of Prototype Rubber Suspension for Agricultural Machine

This article deals about the experimental analysis of the effect on agricultural machine using rubber suspension and driving on testing track. Rubber suspensions with differential size of cross section and without rubber suspension are used during the analysis.

P. Syrovatka, F. Lopot, M. Janda

Contribution to the Methodology of Measuring Transmission Error

Measuring of transmission error is a complex problem, which includes many variables in process. This contribution describes problems which we encounter during preparation of methodology for measuring transmission error on gears made with different manufacturing precision. Mainly the problems of not repeatable measuring are concerned, which are caused by changes in temperature.

M. Trochta, Z. Folta, M. Burián

Climate Chamber for Testing of Multiaxial Loading

This paper describes the equipment for testing materials in different climatic conditions with control of humidity environment. The described device allows testing of samples for tension, pressure and multiaxial loading. For static testing can be samples used in separate of clima camber or in external clima chamber with chance of fixture sample and additional members for the electronic transfer of accurate readings to an external computer with assesses software. In the described system are recorded maximum and minimum values for measurements with a demonstration of the possibility of measuring outcomes.

D. Vejrych, R. Martonka, R. Kovář

Nanotechnology

Frontmatter

System for High-Temperature Calcination of Nanofibers

From past there is known a process for producing nanofibers. At present, there is the question of how to increase the productivity of their production. At the University of Liberec was developed principle of spinning from a roller. The system is made from spinning electrode and a collector, which are placed in an electric field. Using a modification of both parts is possible to change a value of intensity in the vicinity of both electrodes. This is able to leads to improve production of nanofibers. When correct settings are used, we can call this option the continuous process of nanofibers production. There is a theory that we can carry on more than one process of electrospinning in a closed space. After the process of spinning is necessary to subsequently modify the collected material. In this case, the material is composed by plastic parts, organic parts and titanium oxide. For the separation of titanium oxide is necessary to burn the material at the required temperature. After burning process it is possible to receive clear titanium oxide. For this task was build experimental furnace as a last part of production line.

R. Kovář

Backmatter

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