Machine Manufacturing Technology

I. INTRODUCTION Sliding bearings are involved in wide ranged fields of operation considering their outstanding properties as accuracy, endurance, rigidity, low friction levels, superior behaviour during vibrations or oscillating strains. Besides they are able to work in contaminated ...

Micro injection molding is a domain which implies challenges for both producers of moulds and technologists. Due to special conditions required by the process of micro injection molding, chemical, physical and thermal properties of the injected polymeric material are affected, material behaviour is different compared with that during the classical process of injection moulding and so, optimization of parameters of the injection process is needed. This work has shown the process of optimization of micro injection in template given a medical application. A numerical analysis has been performed using the Autodesk Moldflow Insight software given a "surgical micro-stitch" marker device.

This paper presents the results of the researches with application in production for the innovative realization of the double gear pumps with minimum axial gauge and minimum number of parts for the increase of reliability in use and reducing the production costs. The innovative design characteristic is represented by adaptive dimensioning with minimum gauge, depending on requirements, the type of drive, the fixing method, the connections for the hydraulic circuit and intermediary sealing between stages which allows the operation with different liquid mediums. The innovative technological characteristic is on integrated adaptive system (lean production) using computer assisted manufacturing on CNC machines with minimal production time and high quality. This way of production of double gear pumps is obtaining significant reductions in the cost of manufacturing and much smaller gauges the double pump available on the market.

The paper deals with a new and modern technology used to test the tightness of the vehicles radiators or heat exchangers. This technology involves a dry testing method, different from the present one, which requires huge amounts of water and afterwards drying devices, that lead to increased costs of the product and environmental damage. We intend to propose a new testing possibility and prove its advantages in comparison to the one used at the present moment.

This paper presents a case study on the redesign of polymeric greenhouse clips using function analysis (FA), advanced computer aided design/computer aided engineering, reverse engineering and additive manufacturing applications. In the case study, based on a reverse engineered existing clip, alternative redesigns for five concepts have been created in consideration of the initial design needs and FA response. Finite Element Analysis (FEA) has been utilised to simulate and validate the operating conditions of the selected candidate alternative design. No failure cases were observed in the FEA validation. Finally, physical prototypes were produced and the final decisions have concluded that the selected candidate design responded to the defined FA needs.

The use of additive manufacturing (AM) systems in scale production has rapidly increased in recent years. The growing tendency to adopt AM technologies into established manufacturing systems has led to research that considers the optimisation of both process and resource planning. In order to maximise the outputs of such a production process, planning must be conducted rigorously. This paper proposes an automated software tool, called EasyPlan, which streamlines the optimisation of resource planning. The algorithm is developed using LabVIEW and is demonstrated for an AM component from the medical industry. For the evaluation process, parameters such as stock levels, delivery terms and technical charts of the products are provided. A user friendly interface is developed, making EasyPlan versatile to all types of environments.

In this paper, the authors show an original methodology for optimization of tool geometry used in the milling of spherical surfaces. This methodology is based on thorough theoretical research, which highlights the kinematic characteristics of spherical surface generation by milling. These characteristics lead to the conclusion that the constructive angles of tools used in spherical surface milling must have the same values on both cutting edges. The paper also presents a practical design methodology of these tools, both for exterior spherical milling, and for interior spherical milling. The theoretical research was validated by manufacturing physical tools used in processing spherical joints from 330 MW turbines, as well as in processing of sphere taps used in the petrochemical industry.

This paper presents research into the development of an algorithm developed in a Visual Basic programming environment that aids in the selection of materials processed using additive manufacturing (AM) technologies. AM technologies such as selective laser sintering (SLS) and fused deposition modelling (FDM) have limitations on the materials available to them and each system has factors that limit the geometric freedom of the components that they can produce. Thus, materials capable of being processed on these types of technology can be selected through a method of traversing the geometric features of a computer aided design (CAD) model and performing an analysis of each individual feature's attributes. The algorithm developed for this research uses data based on minimum feature size and a model bounding box as criteria in the selection of suitable materials. Through integration with an existing commercially available CAD software package, a component can be automatically analysed for its geometric feature properties and attributes, Allan E.W. Rennie has been the Head of the Lancaster Product Development Unit, Lancaster University since 2002. Formerly, he worked in the additive manufacturing industry for a UK SME, where he was active in research and development. His main interests lie in product development, engineering design and analysis, additive manufacturing and their use in prototyping, tooling and end-use manufacturing applications. His funding portfolio has included EU and UK projects totalling approximately £8M and collaborations with approximately 650 private sector companies. He organises the annual Rapid Design, Prototyping & Manufacturing Conference, reviews papers for international journals and conferences and has assessed research grant proposals for a number of funding bodies internationally.

Additive manufacturing (AM) methods are currently utilised for the manufacture of prototypes and low volume, high cost parts. This is because in most cases the high material costs and low volumetric deposition rates of AM parts result in higher per part cost than traditional manufacturing methods. This paper brings together recent research aimed at improving the economics of AM, in particular Extrusion Freeforming (EF). A new class of machine is described called High Speed Additive Manufacturing (HSAM) in which software, hardware and materials advances are aggregated. HSAM could be cost competitive with injection moulding for medium sized medium quantity parts. A general outline for a HSAM machine and supply chain is provided along with future required research.

În lucrare se prezintă o nouă metodologie de dezvoltare a produselor pentru aplicaţii ale tehnologiilor de fabricare aditivă. Metodologia are la baza tehnici ale analizei functionale tehnice, fiind aplicată la reproiectarea unui instrument chirurgical pentru intervenţii oculare. Cercetările evidenţiază îmbunătăţiri semnificative în funcţionalitatea produsului şi reducerea costurilor de producţie. Designul unic şi inovant al produsului, a obţinut recenzii excelente după testele în laborator şi in vivo. Simulări la oboseală s-au efectuat atât pentru materiale specifice prototipurilor, cât şi pentru cele biocompatibile în vederea comercializării pe piaţă în producţie de serie. Rezultatele cercetărilor sunt folosite de sistemul naţional de sănătate din Marea Britanie pentru lansarea unui nou produs competitiv. This paper presents a methodology on designing for additive manufacturing applications using technical functional analysis tools. The methodology is applied to the redesign of a device for intravitreal interventions. The present research leads to significant improvements in product functionality and reduction of manufacturing costs. The unique and innovative design of the product had encouraging reviews after laboratory and in vivo testing. Fatigue simulations were deployed for both prototyping materials and biocompatible materials, in the hopes of series production. Results of the current study are being used by a commercial company in the United Kingdom to support the launch of a new competitive product.

Globally, the number of people of all ages visually impaired is estimated to be 285 million. Almost half of these visual impairments require surgical intervention by means of treatment. The current paper proposes a theoretical research strategy to set the background on developing innovative and affordable solutions to the global problem of accessibility to ophthalmological corrective surgeries. These solutions are reflected both in the application of additive manufacturing (AM) technologies to obtain bespoke ophthalmic surgical instruments and in providing a set of software tools designed to assist the medical process for improved overall results.

A variety of methods and tools for product design have been developed and introduced in recent years within high-tech enterprises to improve their competitiveness. The positive consequences of their use are indisputable: without them, it would not be possible to shorten development cycles, reduce costs and improve product quality and reliability. Deploying Technical Functional Analysis (TFA) techniques in the field of additive manufacturing (AM) brings the following significant benefits: lower costs; reduction in material consumption; reduction in manufacturing time; shorter time-to-market; improving the accuracy of certain operations; improving the efficiency of studied processes and procedures. The design of a product determines: functions; choice of materials; dimensions; design; performance; assembly conditions; tolerances etc. Consequently, quality and cost (future costs) are attributable to 70-75% following the end of the design phase. The application of TFA, along with method...

Drip irrigation techniques have been used in the agricultural production industry as an advanced water-saving irrigation method in recent decades. However advantageous this method, there are still some difficulties in projecting the efficiency of such systems. Most especially, determination of the losses because of the emitters is very important in order to set up an efficient irrigation system. This study is focused on determining head losses for agricultural drip irrigation systems with cylindrical in-line type drip emitters using Computational Fluid Dynamics (CFD) techniques. In the study, three-dimensional solid models of five in-line type drip emitters, which have a volumetric flow capacity of 4.0 [l h-1] and placed in a pipe with 250 [mm] intervals between each other, were considered and CFD analyses were carried out with different inlet pressure values. According to the results of the CFD analyses, hydraulic losses were calculated globally and locally and analysis outputs wer...

The engineer nowadays needs to possess knowledge that will enable the design of more diverse and cheaper products, but of higher quality, which reach the market faster, and do not pollute. These requirements are the effect of globalization, competition, reduction of the life-cycle of a product, managing the environmental issues, increasing computing power related to communication networks etc. The present paper proposes research applying technical functional analysis for the development of a surgical device manufactured from biocompatible silicone rubber. The vacuum surgical device is a treatment instrument for skin ulcers resistant to antibiotics and difficult to treat because of other connected diseases. The product is fabricated by open mould casting in a selective laser sintered (additive manufactured) mould, obtained after performing functional analysis. Functional analysis is applied to establish the optimum mould concept and the technological process of manufacturing it. Addi...