• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.6
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• pp.136-141
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• 2016

The purpose of this study is to examine the basic design of a submerged cryogenic pump, which is a two stage impeller pump. We limited this study to the impeller design of the submerged pump. We calculated its velocity triangle based on the impeller blade configuration and, in order to check its natural frequency, we carried out a modal test using a finite element method (FEM) analysis. Basically, modal test results had quite similar to FEM analysis.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.1
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• pp.17-23
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• 2017

This study is about the development and revision of a blower design for a ventilation system. In this study, to describe the flow in the 4000CMM grade blower, 3-dimensional steady-state turbulence was assumed to govern the flow equation. The flow field with velocity distribution according to the elbow duct of the ventilation system is also compared. Finally, vibration was observed in the blower at the installation to ventilation system. The cause was due to a problem in the manufacturing process of the airfoil type impeller.

• Transactions of Materials Processing
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• v.16 no.4 s.94
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• pp.288-292
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• 2007

This study focuses on the warm forging of a magnesium alloy impeller used for the fuel cell. The impeller has the very complicated shape with sharply twisted blade and thus is generally produced by mechanical machining or casting process. However, since these technologies give the high manufacturing cost or poor mechanical properties, the forging technology is required to make the high-quality impeller with the lower manufacturing cost. In order for production of the impeller by warm forging technology, the parametric studies using finite element analyses were carried out to find the optimal perform shape of impeller. Based on the FE simulation results, dies for impeller forging were designed and the resultant forged impeller was shown.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.4
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• pp.40-46
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• 2013

When impeller machining needs to be machined over a length in order to avoid interference with neighboring surfaces between material and tool, there are no databases about cutting condition according to tool slenderness ratio. So selection and machining of cutting condition depends on expert's experience. Therefore, the purpose of this paper is deciding cutting condition in roughing and finishing process of impeller according to slenderness ratio of AL7075's end-mill that is the most commonly used for impeller. We have tested for about relation between Slenderness ration and fluctuation width of the cutting force, surface roughness and depth of cut ratio to observe cutting characteristics according to slenderness ratio. The experiments of cutting characteristics and processing criteria are compared with AL5052 which is existing information.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.3
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• pp.9-15
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• 2017

This study represents basic research for the development of submerged pump technology applicable to transfer and storage of a cryogenic liquids. Its purpose is to secure baseline design data by applying reverse engineering to the process of developing a submerged cryogenic pump. The two-stage model included in the ARTICK Series LNG Submerged Pump produced by Vanzetti of Italy was selected for analysis for development of a localized product, and was disassembled for reverse engineering. The pump was disassembled after analyzing its processing/assembly characteristics such as shrinkage of fittings. In addition, the materials used in manufacturing of the main components were analyzed, and the ingredients were confirmed. As a result, a design drawing for each component required for product development was secured via foundational design, and a test product was manufactured by maximizing the application of appropriate domestic technologies.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.435-436
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• 2009

In the effort on cost reduction in marine equipment company, the medium sized impeller blade ($500mm{\times}200mm{\times}20mm$) of an axial flow pan was manufactured by the high pressure die casting, with which was replaced the gravity die casting. High pressure die casting is a practical alternative because of some advantages such as excellent accuracy and smooth cast surface as well as cost reduction if a certain amount of porosity in the parts can be minimized. In order to reduce the porosity in the center of the neck which is thickest region of the impeller blade, the several gate designs were proposed in this work. The flow simulations for each gate design were performed and then the optimal design was determined by considering the air pressure distribution in neck section. Finally, the size of porosity in the neck of the die cast impeller blade for optimal design was less than 1mm, which satisfied the requirement.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.10
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• pp.48-53
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• 2019

A water jet propeller is a key component that generates propulsion during the start of a naval vessel. When failure or breakage occurs, the vessel cannot operate. Recently, a flow analysis and structural analysis were conducted to understand the cause of damage to a bolt on a water jet. In particular, the stress and strain acting on the fastening bolt (impeller shaft and tail shaft) were examined to determine the extent of misalignment between the impeller shaft and the tail shaft of the water jet propeller. The study determined that stress and strain were concentrated on the impeller shaft and the tail shaft bolt. The alignment of the propeller impeller shaft and the tail shaft increased significantly in response to the tail shaft bolt. Failure of the tail shaft bolt fastening can lead to misalignment between the impeller shaft and the tail shaft.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.12
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• pp.71-77
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• 2021

An impeller identification technique that is essential for adding viscosity measurement functions to overhead stirrers is presented in this study. Previous studies have revealed that using magnets facing the same poles arranged in a row can aid in distinguishing the types of impellers by detecting the number of magnets in a non-contact manner. However, as these previous studies measured the magnetic fields using analog Hall sensors, a converting circuit for the digital signals is required that can interface with the MCU. In this study, it was demonstrated that the number of magnets can be distinguished without using a separate conversion circuit by using a Hall sensor with a digital output. Owing to the unique hysteresis characteristics of digital Hall sensors, it was confirmed through experiments that the complex and diverse outputs appear depending on the direction of the magnetic field, the arrangement of magnetic poles, and the moving direction of the magnet. The measurement of the magnetic field showed that an edge signal equal to the number of magnets inserted into the impeller was detected when the radial direction was used, and the south pole was first approached.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.175-180
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• 2000

This paper describes the method and the process for impeller machining on 5-axis CNC machining center. Also, The CAD/CAM software for the impeller post processing is developed. The software can be interfaced with Solid-works software for confirmation of the impeller shapes. In this study, blades on impeller is described from Ruled-surfaces between two Ferguson curves. In this study, using 5-axis NC part program obtained from the developed software, a sample impeller was machined on 5-axis CNC machining center. The machined impeller was very agreeable to the designed impeller. Thus, theories proposed in this study can be very useful for the 5-axis machining of impeller blades with Ruled-surfaces.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.12
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• pp.1088-1095
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• 2008

5-axis NC machining has a good advantage of the accessibility of tool motion by adding two rotary axes. It offers numerous advantages such as expanding machining fields in parts of turbo machineries like impeller, propeller, turbine blade and rotor, reasonable tool employment and great reduction of the set-up process. However, as adding two rotary axes, it is difficult to choose suitable machining conditions in terms of tool path, tool posture, feedrate control at a tool tip and post-processing. Therefore in this paper, it is proposed to decide suitable machining condition through an experimental method such as adopting various tool paths, tool postures, and feedrate types. Machining experiment on AL7075 for impeller is performed to define suitable machining condition, and measurement of surface roughness on machined surfaces depended on each machining condition is performed. By defining suitable machining condition, we should have conclusion as improving the surface quality in the aspect of surface roughness and machined shape of surface.