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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.
51

CFD-aided optimization of customer-specific tank systems using an innovative labyrinth deaerator

Wartlick, Karl, Baumann, Matthias, Veres, Andras, Weidemann, Roman 25 June 2020 (has links)
This paper introduces the comprehensive approach of ARGO-HYTOS in developing and optimizing hydraulic tanks. Starting with a detailed analysis of the application, the tank design was optimized and an innovative deaerator was developed. In a first step, various Computational Fluid Dynamics (CFD) -based analyzing methods are presented, which are used to support the optimization process of tank development with regard to complex flow conditions and unexpected influences. The main topic of this paper is the introduction of an innovative labyrinth deaerator, causing coalescence of air bubbles, slower subsequent flow conditions and finally a better deaeration. A further focus is on a customized deaeration test rig, which is used to validate improved components and tank designs on the one hand and to learn more about the complex deaeration effects on the other hand. With this comprehensive optimization approach and the innovative, compact and patented labyrinth deaerator, the size of the tank and the amount of oil can be reduced to a minimum, without impairing air separation, but on the contrary, even improving the air separation behavior.
52

Validation of a soft sensor network for condition monitoring in hydraulic systems

Hartig, Jakob, Schänzle, Christian, Pelz, Peter F. 25 June 2020 (has links)
With increasing digitization, models are more important than ever. Especially their use as soft sensors during operation offers opportunities in cost saving, easy data acquisition and therefore additional functionality of systems. In soft sensor networks there is redundant data acquisition and consequently the occurrence of inconsistent values from different soft sensors is encouraged. The resolution of these data-induced conflicts allows for the detection of changing components characteristics. Hence soft sensor networks can be used to detect wear in system components. In this paper this approach is validated on a test rig. It is found, that the soft sensor network is capable to determine wear and its extent in eccentric screw pumps and valves via data induced conflicts with relatively simple models.
53

Predictive maintenance with a minimum of sensors using pneumatic clamps as an example

Gauchel, Wolfgang, Streichert, Thilo, Wilhelm, Yannick 25 June 2020 (has links)
In standard pneumatics, the available signals for data analytics are very limited. As a rule, no continuous status information is available. Usually only the reaching of the end position is indicated - by means of a digital signal of a proximity sensor. This paper examines whether these limited data can be used to derive usable and useful information for predictive maintenance. Pneumatic clamps in bodyin- white construction were chosen as application example. The paper describes a continuous run to investigate the basic feasibility of predictibility. In the following chapters, possibilities for error classification are discussed. Finally, the implementation of the findings in a field test is described.
54

Development of a lumped parameter model of an aerospace pump for condition monitoring purposes

Mkadara, Geneviève, Maré, Jean-Charles 25 June 2020 (has links)
This paper presents the development of a helicopter axial piston pump model with condition monitoring in mind. Industrial constraints and needs ask for modelling with a lumped-parameter approach and require model architecture to be addressed with care. The aim of the proposed model is to assess the merits of pump leakage monitoring through measurement of case pressure. Once reviewed the state of the art in pump modelling, the slipper/swashplate interface is taken as an example to propose and implement in Simcenter AMESim a variable gap height model. The simulation results show that commonly used lumped-parameter models overestimate leakage. It also points out that average leakage at slipper may reverse at high pump displacement.
55

Flexible and easy to engineer servo-hydraulic actuators using 3D printing manufacturing process

Thienen, Stefan, Gellner, Thomas 25 June 2020 (has links)
Already since some time, Bosch Rexroth offers solutions as compact servo hydraulic actuators (SHA). Because there are lot of requests from the market, we thought about reducing the inquiry processing time and delivery time by designing a kit system for the SHA solutions. This system should be flexible enough to cover different technical solutions (e.g. cylinder), functionalities and design styles [... aus dem Text]
56

Electro-hydrostatic compact drives with variable transmission ratio

Kolks, Giacomo, Weber, Jürgen 25 June 2020 (has links)
Electro-hydrostatic compact drives are an emerging technology within a range of industrially available translational drive solutions, combining the specific advantages of hydraulic and electromechanical screw drives. Compared to electromechanical screw drives, hydrostatic drives can vary their transmission ratio with comparably little effort, giving them the key advantage of downsizing the electric drive components for a given load cycle. This paper provides a guideline on how to calculate the downsizing potential of electric motors and inverters arising from variable transmission ratio based on the load regime of a given application. Furthermore, a comprehensive systematisation of the actual switching process is described for systems that are switched by means of switching valves. The presented set of methodology is applied to demonstrators in order to validate the general findings.
57

Pneumatics and Industrie 4.0 - opportunity or contradiction?

Post, Peter 26 June 2020 (has links)
Modern industrial production processes are increasingly characterized by digital solutions in order to continuously increase their efficiency while taking sustainability aspects into account. Pneumatic components and systems have been and will continue to be an essential part of modern production plants and must face the special challenges posed by digitalization [... aus dem Text]
58

Behaviour and impact of leakage in vacuum gripping systems

Straub, David 26 June 2020 (has links)
Leakage in a vacuum system causes the pressure to rise if it is not compensated like in case the supply energy carriers fail. This leads to the workpiece to be dropped. So in order to design vacuum gripping systems that can withstand a failure of the supply energy carriers over a predefined amount of time, it is crucial to know the influences and effects of leakage. In previous examinations the behavior of leakage has been examined on the basis of a closed fluidic reservoir with a hole in its wall. But the only impacts taken into account here are the volume of the reservoir, the diameter of the hole and the pressure difference. Whereas when it comes to vacuum gripping systems, the leakage has significantly more influencing factors as it is neither a single component nor a closed system. In vacuum gripping systems leakage mostly occurs at the interface between the suction cups and the workpiece. So in this contribution the focus is on the impact of the properties of those components, and how the variation of these properties affects leakage. To achieve this, a theoretical description is done based on the aforementioned research, which is expanded in order to the relevant characteristics of a vacuum gripping system. After that the description is evaluated on a test bench. The goal is to be able to make a statement about the leakage rate for a vacuum gripping system composed of standard components. This can then be used in the design process of such gripping systems, which have to fulfil the requirement of compensating leakage in case the energy supply fails.
59

Much does not help much: 3D pareto front of safety, comfort and energy consumption for an active pneumatic suspension strut

Rexer, Manuel, Brötz, Nicolas, Pelz, Peter F. 26 June 2020 (has links)
With regard to autonomous driving the demands on comfort are increasing. This makes it attractive to use active suspension systems. The system developed at TU Darmstadt is able to increase driving comfort up to 28 % while maintaining driving safety compared to a passive suspension system. This paper investigates the influence of available energy and power of the active system. The investigation is based on a simulation of a quarter car model and an uneven country road. This paper shows that the more energy the active system has at its disposition, the greater is the range between a comfortable and a sporty chassis. Furthermore the driving comfort can be increased by 28 % with constant driving safety. The average power required for this is 15 W and the maximum power is 300 W.
60

Energy efficiency in pneumatics with the 'Air Saving Box': the revolutionary plug & play solution from SMC

Heitmann, Mario, Rein, Ferdinand 26 June 2020 (has links)
For many companies, energy efficiency starts with production. For this reason, special consideration must be given to the production operation as a whole as well as its sub-areas. The strict legal requirements, as well as the companies`green policies which are defined as a result of these, create complex challenges, which SMC meets with expertise and passion as a manufacturer, partner and solution provider in electric and pneumatic automation technology. On the basis of an actual customer requirement, SMC Germany has developed an innovation in the field of pneumatic energy efficiency: The Air Saving Circuit for double acting pneumatic cylinders , under the working title of Air Saving Box . The underlying idea and focus of the solution was to make good use of the compressed air generated in existing cylinders, instead of simply allowing it to go to waste. The Air Saving Box enables significant energy savings in production. Based on this customised solution, SMC has also developed an industry-independent concept that can also be integrated into existing applications.

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