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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.
1

From reliable sensors to cylinder intelligence

Casper, Leo, van de Loo, Jasper 03 May 2016 (has links) (PDF)
Reliability of a piston rod position measurement system is key when applied to large hydraulic cylinders. This and other requirements lead to the development of the CIMS (Cylinder Integrated Measurement System), a contactless and highly accurate system that uses the Hall effect to detect an encoded piston rod. To eliminate deviations caused by mechanical tolerances, temperature and air gap variations etc., the raw signals are filtered and compensated. Its functionality has been extended by making statistical data available, based on the values measured. These include the number of strokes, cumulative stroke length, stroke length distribution, maximum velocity and acceleration, temperature classification and extreme temperatures. Assessment of these data enables the user to optimize his application. Comparison to historic data can give input to the preventive maintenance plan to reduce (unforeseeable) system downtime and to increase the system reliability. This development resulted into the CIMSmart. It is a significant step towards cylinder intelligence.
2

Dirt Ingress Behavior of Wipers for Hydraulic Cylinders

Barillas, Gonzalo A., Richter, Sören, Weber, Jürgen 28 April 2016 (has links) (PDF)
Dirt ingress in hydraulic cylinders is one of the sources that leads to pollution of hydraulic systems. There are already several test rigs to investigate external contamination mechanisms. However, until now only the behavior of the whole sealing system was analyzed. A new testing method to understand the dirt particle transport between a reciprocating motioned rod and a wiper is presented. The new approach aims to avoid known issues such as limited reproducibility and long duration. The paper describes the test rig design and operating principle. First measurement results are shown.
3

Didelės galios hidraulinės sistemos droselinio greičio reguliavimo tyrimas / High power hydraulic speed control system of a butterfly survey

Kobec, Roman 18 June 2010 (has links)
Darbo apimtis yra 51 puslapių, jame yra 23 paveikslėliai. Literatūros aprašą sudaro 36 literatūros šaltiniai. Pagrindinis tiriamojo darbo tikslas – išanalizuoti hidraulinio cilindro stūmoklio greičio charakteristikų priklausomybę, keičiant hidraulinio cilindro apkrovą bei esant pastoviam siurblio slėgiui. Magistrantūros baigiamąjį darbą sudaro trys dalys: literatūros apžvalga, teoriniai tyrimai ir eksperimentiniai tyrimai. Literatūros apžvalgoje pateikiama droselinės hidraulinių sistemų reguliavimo sistemos, automatizuotos sistemos bei jų sandara. Teoriniuose tyrimuose yra išnagrinėtas droselinis valdymas ir reguliavimas, jo veikimo principai, naudingumo koeficientai bei galios balansas. Eksperimentiniuose tyrimuose yra išnagrinėta hidraulinio cilindro stūmoklio greičio charakteristikų priklausomybė nuo hidraulinio cilindro stūmoklio judėjimo greičio bei apkrovos. Sumontavus specialią hidraulinę sistemą atlikti hidraulinio cilindro stūmoklio greičio charakteristikų tyrimai. / Volume of work is 51 pages and contains 23 pictures. References inventory consists of 36 literary sources. The main aim of the investigation - to analyze the hydraulic cylinder shaft speed characteristics of dependency, changing the working pressure of hydraulic system and droseliavimo character. Master's thesis consists of three parts: an overview of sources of information, an overview of theoretical studies and experimental studies. Review of information sources describe butterfly hydraulic systems framework, addresses the butterfly speed control characteristics. The work purpose – to find out features of throttle adjustment of speed of movement the piston of hydraulic system of the big capacity. Experimental researches have been carried out with earlier described device. In the hydraulic cylinder design changes have been executed, the sizes and throttle place by means of theoretical throttle characteristic ADR = f(h) are changed. For reduction of turn time of a working platform it was necessary to increase pressure in hydraulic systems with 60 to 70 bar. Pressure increase has allowed piston to increase speed of movement. These changes have specified on a smooth stop of a working platform a problem. Time of turn of a working platform has decreased till 1,31 seconds. The piston pressure in the braking chamber is equal in last phase of work 48 bar, it tells about prevention of blow the piston about the hydraulic cylinder.
4

Návrh technologie výroby vybrané součásti v systému regulace parní turbíny / Proposal of technology a selected component in the control system of steam turbine

Hradil, Roman January 2017 (has links)
The subject of this thesis is the design of production technology of the hydraulic cylinder – the part of servomotor of a steam turbine control valve. The main precondition is a perspective technology of manufacturing the component on a single workplace using Siemens NX10 CAM system. The implementation of this work was carried out in cooperation with the Siemen, s.r.o., the branch of Industrial Turbomachinery in Brno. Part of the thesis is a brief introduction to the issue of steam turbines. The main part is devoted to analysis of a selected component in terms of technology, design of the best strategy of production technology and its implementation. The conclusion deals with the technical and economic assessment of the proposal.
5

Dirt Ingress Behavior of Wipers for Hydraulic Cylinders

Barillas, Gonzalo A., Richter, Sören, Weber, Jürgen January 2016 (has links)
Dirt ingress in hydraulic cylinders is one of the sources that leads to pollution of hydraulic systems. There are already several test rigs to investigate external contamination mechanisms. However, until now only the behavior of the whole sealing system was analyzed. A new testing method to understand the dirt particle transport between a reciprocating motioned rod and a wiper is presented. The new approach aims to avoid known issues such as limited reproducibility and long duration. The paper describes the test rig design and operating principle. First measurement results are shown.
6

From reliable sensors to cylinder intelligence

Casper, Leo, van de Loo, Jasper January 2016 (has links)
Reliability of a piston rod position measurement system is key when applied to large hydraulic cylinders. This and other requirements lead to the development of the CIMS (Cylinder Integrated Measurement System), a contactless and highly accurate system that uses the Hall effect to detect an encoded piston rod. To eliminate deviations caused by mechanical tolerances, temperature and air gap variations etc., the raw signals are filtered and compensated. Its functionality has been extended by making statistical data available, based on the values measured. These include the number of strokes, cumulative stroke length, stroke length distribution, maximum velocity and acceleration, temperature classification and extreme temperatures. Assessment of these data enables the user to optimize his application. Comparison to historic data can give input to the preventive maintenance plan to reduce (unforeseeable) system downtime and to increase the system reliability. This development resulted into the CIMSmart. It is a significant step towards cylinder intelligence.
7

Independent Steering : Rear steering axle with independent actuators

Blixt, Emil, Svensson, Albin January 2024 (has links)
The thesis has been done in collaboration with Kalmar Solutions AB and is a conceptual study that aims to design a hydraulic steering arrangement for the reachstacker DRG 450 where each wheel is steered independently of each other. This is done in order to reduce tire wear by achieving an Ackermann steering geometry; lesser tire wear reduces costs for customers. When steered independently of each other the same steering arrangement could be used on multiple different wheelbases while still achieving an Ackermann steering geometry. During the thesis, calculations for required steering angles and their required piston strokes has been done by creating a geometrical model of the steering arrangement. CAD-modeling and kinematic simulations of concepts has been conducted with CATIA R2024x where the concepts movement when turning could be simulated. Three main concepts of the steering arrangement were studied and developed during the thesis. Kinematic simulations concluded that by changing to two independent cylinders, along the same axis, and redesigning the steering knuckles could allow for the same steering arrangement to achieve an Ackermann steering geometry for multiple different wheelbases. This reduces tire wear and turning radius when compared to the current steering axle. Having the cylinders along the same axis proved to be best because less redesigns were needed and mainly no major redimensioning of the steering arrangement or chassis were needed.
8

Produktionsflödesanalys - CA-Verken i Sävsjö / Production flow analysis - CA-Verken in Sävsjö

Håkansson, Jacob, Vakaricic, Isidora January 2007 (has links)
Examensarbete utfördes på CA-Verken i Sävsjö som bl.a. tillverkar hydraulcylindrar. De senaste två år har CA-Verken haft en kraftig ökning av omsättningen och det som står i vägen för fortsatt expansion är produktionen som har begränsad kapacitet. Målet med detta arbete är att studera CA-Verkens produktionsflöde för att kunna identifiera flaskhalsen/flaskhalsarna och därefter ge förslag på lösningar och förbättringar. Den teorin som har använts som grund till arbetet är Theory of Constraints (TOC). Intervjuer, företagets affärssystem och observationer har använts vid datainsamling. Genom analysering av produktionsflödet för cylindrar som står för den största delen av omsättningen identifierades monteringen som flaskhals. För att kunna optimera produktionsflödet krävs det att monteringen utnyttjas effektivt samt att olika störningar och slöserier i monteringsprocessen elimineras. / This diplomawork is a study of the making of hydraulic cylinders at CA-Verken, a Swedish company located in Sävsjö. The last two years has showed a substantial increase of the company’s turnover. The only remaining obstacle of an ongoing expansion is the limited capacity of the company’s production. The purpose of this diplomawork is, for that particular reason, to study CA-Verkens production flow in order to identify the bottleneck-issues and ultimately be able to suggest possible solutions and improvements concerning the production process. The theoretic foundation of this study is based on the Theory of Constraints (TOC). Interviews, company business systems and observations have been used as important sources during the collection of data. By analysing the production flow concerning the cylinders, which represents the greatest deal of the company’s turnover, the assembly was identified as a bottleneck-issue. In order to optimize the torrent of production it’s necessary for the company to increase the efficiency of the assembly and eliminate different disturbances as well as all unnecessary wastefulness in the process.
9

Produktionsflödesanalys - CA-Verken i Sävsjö / Production flow analysis - CA-Verken in Sävsjö

Håkansson, Jacob, Vakaricic, Isidora January 2007 (has links)
<p>Examensarbete utfördes på CA-Verken i Sävsjö som bl.a. tillverkar hydraulcylindrar. De senaste två år har CA-Verken haft en kraftig ökning av omsättningen och det som står i vägen för fortsatt expansion är produktionen som har begränsad kapacitet.</p><p>Målet med detta arbete är att studera CA-Verkens produktionsflöde för att kunna identifiera flaskhalsen/flaskhalsarna och därefter ge förslag på lösningar och förbättringar. Den teorin som har använts som grund till arbetet är Theory of Constraints (TOC). Intervjuer, företagets affärssystem och observationer har använts vid datainsamling. Genom analysering av produktionsflödet för cylindrar som står för den största delen av omsättningen identifierades monteringen som flaskhals.</p><p>För att kunna optimera produktionsflödet krävs det att monteringen utnyttjas effektivt samt att olika störningar och slöserier i monteringsprocessen elimineras.</p> / <p>This diplomawork is a study of the making of hydraulic cylinders at CA-Verken, a Swedish company located in Sävsjö. The last two years has showed a substantial increase of the company’s turnover. The only remaining obstacle of an ongoing expansion is the limited capacity of the company’s production.</p><p>The purpose of this diplomawork is, for that particular reason, to study CA-Verkens production flow in order to identify the bottleneck-issues and ultimately be able to suggest possible solutions and improvements concerning the production process.</p><p>The theoretic foundation of this study is based on the Theory of Constraints (TOC). Interviews, company business systems and observations have been used as important sources during the collection of data. By analysing the production flow concerning the cylinders, which represents the greatest deal of the company’s turnover, the assembly was identified as a bottleneck-issue.</p><p>In order to optimize the torrent of production it’s necessary for the company to increase the efficiency of the assembly and eliminate different disturbances as well as all unnecessary wastefulness in the process.</p>
10

Návrh uložení hydraulického válce zkušebního zařízení kulových kloubů / Assembly Design of Ball-Joint Test Bench Hydraulic Unit

Novák, Jiří January 2009 (has links)
The main object of this thesis is the proposal of fitting (setting) hydraulic cylinder into test equipment of ball-joints of company TRW-DAS Dačice a.s. The thesis includes a short review about testing ball-joint of above company and about liquid mechanisms. Also, there are analyzed demands for fitting (setting) hydraulic cylinder into testing equipment. In the main part of this thesis there is described my own constructive proposal with numeric calculations in proper software. In enclosure there are all analytical calculations with productive drawings and an assembly drawing.

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