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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

Development of New Lifting Equipment for VPA Plates

Batchuluun, Bolormaa January 2016 (has links)
This thesis explores how to develop new lifting equipment for the membrane and filter plates of the VPA (Metso) machine satisfying all the safety requirements. The VPA is a heavy duty machine with a number of plates, developed for filtration of minerals. The plates must be replaced or removed immediately once the wear has reached a given value or an error has been detected. The new lifting system differs to a great extent from conventional system in which a fiber strap was used; the designed lifting equipment comprises of a variety of parts resulting in a higher capacity to be used ín different situations safer and satisfies the vital requirements such as being a secure and cost-effective method, issued by the customers. Several solution proposals have been developed to offer better proposals before the final candidate has been selected and theoretically motivated with FEM analysis as well as analytical calculations. Keywords - VPA, membrane and filter plate, lifting equipment, pivot supporter hinge, safety, cost effective
2

Effects of elastic resistance on concentric force, concentric power, and eccentric velocity during the bench press

Lawrence, Michael A. January 2010 (has links)
Elastic bands are becoming more popular in strength and power training. Although increases in strength and power have been anecdotally reported with high loads of elastic resistance, there is no research on large band tensions and their effects on force and power variables. The purpose of this study was to quantify peak concentric force, peak concentric power and peak eccentric velocity produced by the subject when using differing levels of elastic resistance (0%, 20%, 50% and 75% of the total load being elastic resistance) in the bench press. Seven experienced male powerlifters and body builders participated in this study. Prior to subject testing all elastic bands were calibrated for force output throughout the bench press range of motion. Each subject performed a single repetition maximum press to determine the total correct testing load (85% of maximum press). The subjects then performed four presses with various elastic band resistances, each having the total equivalent weight of 85% of the subject’s maximal press weight at lockout. Dependent variables were peak concentric force, peak concentric power, and peak eccentric velocity as produced by the subject. A one-way ANOVA was used to determine the differences among the four levels of elastic resistance (ER) used in the study (α = 0.05). Compared to the baseline condition (2123.6 ± 499.9N), significantly lower average peak concentric force was observed with ER of 75% (1451.2 ± 151.0N, 31.9% decrease) (p = .010) and with an ER of 50% (1781.1 ± 174.3N, 16.4% decrease) (p = .052). When compared with baseline peak concentric power (702.6 ± 274.6W), higher peak power was observed in all band trials: 20% (895.2 ± 187.7W, 27.4% increase), 50% (972.5 ± 189.8W, 38.4% increase) and 75% (979.6 ± 171.0W, 39.4% increase) (p = .009; p = .007; p = .033, respectively). There was no significant difference in peak concentric power in any ER trials. No significant differences (p = .080) were seen in peak eccentric velocity. Therefore ER loads of 20, 50 and 75% provide greater stimuli for producing peak concentric power than no ER, with only a 20% load of ER maintaining the same peak concentric force production as baseline. ER loads of 50 and 75% may not be as effective a stimuli as free weights when the training objective is to increase force production. / School of Physical Education, Sport, and Exercise Science
3

Development of guideline template for lifting equipment

Elmgren, Oskar, Sääf Mertala, Alexander January 2022 (has links)
The purpose of this thesis is to develop a guideline template that should supportthe industrial partner when designing lifting equipment. A newly updated standardwith focus on fatigue was the base of the project. The standard divides load cyclesinto over and under 16 000 cycles and they have different requirements. Thisproject explains how to reach these requirements. By interpretation of neededvariables/calculation and how to solve these calculations. A workflow for Finiteelement analysis is presented and analysis is done on lifting equipment. The resulta guideline template with focus on fatigue which indicates which requirementsneeds which solution.
4

Návrh výrobní technologie pro zdvihací zařízení chladiče traktoru / Production technology of a lifting equipment for tractor cooler

Raiskup, Martin January 2019 (has links)
The thesis focuses on production technology of the lifting equipment for a tractor cooler. This device is used in order to ease the installation of a cooler during the manufacturing of a tractor. In the first chapter, various types of the lifting equipment are described. In the following chapters manufacturing methods, machines and tools for the production of the specific component are described. Furthermore, materials and manufacturing processes for the complementation of the specific component are proposed. In the conclusion, the methods for the manufacturing are suggested, the timescale is calculated and the technical-economical evaluation is performed.
5

Návrh manipulačního zařízení výrobní linky / Design of production line handling equipment

Macháček, Jakub January 2019 (has links)
This master's thesis is focused on the design of handling and lifting equipment of production line. This thesis deals with the design of the frame for transverse feed of 100 mm and longitudinal feed of 1500 mm. The thesis deals with the design of several lifting equipment for load capacity 1450 kg and stroke 120 mm. The main part of this thesis is focused on appropriate calculations for selected variants of lifting equipment. The conclusion contains comparison lifting constructions and description equipment in the production line. The thesis contains assembly drawings of several lifting equipment variants and assembly drawings of equipment.
6

Autonomt underhåll av lyftverktyg vid lastarmontering / Autonomous maintenance of lifting tools for loader assembly

Wu, Christy January 2022 (has links)
Totalt produktivt underhåll (TPM) är ett arbetssätt med åtta delaspekter, som fokuserar på att underhålla och förbättra produktionen. Autonomt underhåll (AM) är en av de åtta pelarna och är en underhållsstrategi där maskinoperatörer utför grundläggande underhållsuppgifter samt kontinuerligt kontrollerar sina egna maskiner. Vid arbete med lyftverktyg bör alla komponenter och funktioner kontrolleras regelbundet för att minimera riskerna. Daglig tillsyn är ett lagkrav i många länder, och i Sverige ingår det i Arbetsmiljöverkets föreskrifter AFS 2006:6 30 §, som anger att lyftverktyg ska underhållas och kontrolleras dagligen. Det är lämpligt att genomföra en daglig tillsyn vid början av varje arbetsskifts. Hos Ålö AB saknades rutiner och riktlinjer för hur lyftverktygen som används för montering av frontlastare skall optimalt underhållas, samt instruktioner för det löpande underhållet av lyftverktygen. Syftet med projektet var att höja säkerheten på arbetsplatsen, förebygga ohälsa och olyckor, upptäcka underhållsbehov så tidigt som möjligt samt att öka operatörernas kompetens och kunskap om lyftverktyg. Målet med projektet var att ta fram en instruktion för operatörernas underhåll av lyftverktyg på monteringen av frontlastare. Projektet genomfördes genom faktainsamling, framtagning av olika koncept över process, utvärdering av koncept samt framtagning av ett slutligt koncept.  Den fastställda arbetsrutinen i det slutliga konceptet innebär att daglig tillsyn ska utföras vid olika områden i monteringen. Arbetssättet kombinerar analogdokumentation av den dagliga tillsynen på pappersblanketter med digital efterbearbetning. / Total Productive Maintenance (TPM) is an approach with eight sub-aspects, which focuses on maintaining and improving production. Autonomous maintenance (AM) is one of the eight pillars and is a maintenance strategy, where machine operators perform basic maintenance tasks and continuously check their own machines. When working with lifting tools, all components and functions should be checked to minimize the risk for accident. Daily supervision is a legal requirement in many countries, and, in Sweden, it is included in the Swedish Work Environment Authority's regulations AFS 2006: 6, section 30, which states that lifting tools must be maintained and checked daily. It is advisable to carry out a daily inspection at the beginning of each shift. Ålö AB lacked routines and guidelines for how the lifting tools used for mounting loaders should be optimally maintained, as well as instructions for the ongoing maintenance of the lifting tools. The purpose of the project was to increase safety in the workplace, prevent ill health and accidents, detect maintenance needs as early as possible, and to increase operators' skills and knowledge of lifting tools. The aim of the project was to produce an instruction for the operators' maintenance of lifting tools on the installation of loaders. The project was carried out through fact-finding, development of various concepts over the process, evaluation of concepts and development of a final concept. The specific work routine suggested in the final concept is based on daily inspections must be carried out at various locations in the assembly department. The working method combines analogue documentation of the daily supervision of paper forms with digital post-processing.
7

Étude de la réponse dynamique des ponts roulants soumis à des chocs multiples pendant un séisme : Co-simulation implicite / explicite multi-échelle en temps pour la dynamique du contact / Numerical response of bridge cranes subjected to repeated shocks during an earthquake : Implicit / explicite multi-time scale co-simulation for contact dynamics

Fekak, Fatima-Ezzahra 02 May 2017 (has links)
Les ponts roulants sont des engins de levage situés en haut des bâtiments qu'ils équipent. Ils servent à manutentionner des charges très lourdes et parfois critiques. Pendant un séisme, un pont roulant est exposé à des chocs multiples. Ces impacts peuvent causer des dommages importants dans la structure pouvant conduire à une chute de la charge manutentionnée ou du pont roulant lui-même. Donc, la vérification de la tenue des ponts roulants au séisme est une question primordiale. Actuellement, cette vérification est basée sur des méthodes de calcul statiques. Ces méthodes font l'hypothèse d'un comportement purement linéaire des ponts roulants ce qui les rend très conservatives. Depuis quelques années les niveaux sismiques imposés par les autorités nationales augmentent chaque année, et les constructeurs de ponts roulants se trouvent dans l'incapacité de construire à partir des efforts sur-estimés fournis par les méthodes statiques. L'objectif de la thèse est l'étude de la réponse dynamique d'un pont roulant pendant un séisme en prenant en compte les non-linéarités géométriques et matériau. Afin de modéliser ces phénomènes, une analyse dynamique temporelle avec une approche multi-échelle en temps est adoptée. Pour prendre en compte l'aspect haute fréquence des chocs, un intégrateur temporel variationnel explicite, basé sur la méthode des multiplicateurs de Lagrange et dédié au contact/impact, est développé. Ensuite, un intégrateur hétérogène (différents schémas d'intégration) asynchrone (différents pas de temps), basé sur la méthode de couplage GC, est appliqué au problème du pont roulant. Cette stratégie multi-échelle en temps permet d'adapter le schéma d'intégration et le pas de temps au sous domaine considéré. Par conséquent, l'intégrateur explicite est adopté dans les zones de contact et un schéma implicite de type accélération moyenne, est adopté dans le reste de la structure. Finalement, un démonstrateur de co-simulation entre les logiciels Cast3M et Europlexus est mis en place pour montrer le gain très significatif en temps de calcul dans le cas d'un modèle élément finis tridimensionnel d'un pont roulant industriel. / Bridge cranes are hoisting appliances located overhead in buildings. They are used to handle very heavy and sometimes critical loads. During an earthquake, a bridge crane may be subjected to multiple impacts between wheels and rails. These impacts can cause significant damage to the structure leading to a fall of the handled load or the bridge crane itself. Therefore, the qualification of such equipment, subjected to an earthquake, is very important. Currently, this qualification is based on static methods. These methods assume a purely linear behavior of the bridge cranes, which leads to a very conservative forces. Consequently, the bridge cranes manufacturers are sometimes unable to design the equipement from the over-estimated efforts provided by the static methods. The aim of this work is to study the dynamic response of a bridge crane during an earthquake by taking into account the geometric and material non-linearities. In order to model such phenomena, a time-history dynamic analysis with a multi-scale approach is performed. To take into account the high frequency aspect of the impacts between wheels and rails, a Lagrange explicit contact/impact time integrator is proposed. This work has also led to the development of an explicit–implicit HATI (Heterogeneous Asynchronous Time Integrator) for contact/impact dynamics. This method allows us to adopt an explicit contact/impact time integrator in the contact area and an implicit time integrator with a coarse mesh in the rest of the domain. Finally, a co-simulation demonstrator between Cast3M and Europlexus softwares is set up to show the very significant gain in computation time for a three-dimensional finite element model of an industrial bridge crane.
8

Malá vrtná souprava pro vrtání studní / Small drilling rig for drilling wells

Volec, Martin January 2015 (has links)
The aim of this thesis is the structural design small drilling rigs for drilling wells. Drilling rig will be used for drilling wells up to 200 mm diameter rotary drilling technology with irrigation water. The first part is a literature search of small drilling rigs. In the second part, then custom design a small drilling rig.

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