• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.2
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• pp.184-193
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• 2002

This study aims at the optimal design of the screw rotor and its performance analysis. The optimal design of the screw rotor's shape has been performed theoretically. Also, the performance analysis technique of an oil-injected screw air compressor is developed. The effect of internal leakage, heat exchange between air and oil, and flow resistance at suction and discharge ports are included in the performance analysis. Some numerical examples of the volumetric efficiency and adiabatic efficiency for sample rotors are demonstrated for various lobe combination, rotor wrap angles and L/D ratios.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1285-1288
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• 2005

Screw rotors, the key parts of screw compressors, are used in compressing air and refrigerant due to their high productivity, compact size, low noise and maintenance. In general, a screw compressor is composed of a pair of rotors of complex geometric shape. The manufacturing cost of the screw rotors is high because the complicated helical shapes of the screw rotors are manufactured usually by the dedicated machine tools. In this study, rotor profile is divided into three parts for the efficient machining. The formed tools are designed and shared for the respective split region. By cutting the screw rotor using the formed tools, this method is more efficient than the end mill in machining rotor. Experimental results show that 4-axis machining using formed tools needs less time and has the accuracy.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.901-902
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• 2010

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.10a
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• pp.79-84
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• 1996

Recently a symmetric and non-symmetric profile of screw rotor has been designed in the interior. Howere the processing method of screw rotor and the cutter design for screw rotor were not studied. Therefor we could not make the shape of the screw rotor designed by profile function with computer. In this study we have made cutter profile design program and manufactured cutters for screw rotors using H.S.S We machined screw rotors of symmetric 4x6 profile non-sysmmetric 4x6 profile with almighty milling machine.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.907-912
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• 1994

Recently, a symmetric and non-symmetric profile of screw rotor has been designed in the interior. However the processing method of screw rotor and the cutter design for screw rotor were not studied. Therefore we could we could not make the shape of the screw rotor designed by profile function with computer. In this study, we have made cutter profile design program, and manufactured cutters for screw rotors using H.S.S. We have machined screw rotorts of symmetric 4*6 profile, non-symmetric 4*6 profile with almighty milling machine.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.3
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• pp.103-112
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• 2009

A internal lobe pump is suitable for oil hydraulics of machine tools, automotive engines, compressors, constructions and other various applications. In particular, the pump is an essential machine element of an automotive engine to feed lubricant oil. The subject of this paper is the theoretical analysis of internal lobe pump whose the main components are the rotors: usually the outer one is characterized by lobe with elliptical and involute shapes, while the inner rotor profile is determined as conjugate to the other. And the integrated system which is composed of three main modules has been developed through AutoLISP under AutoCAD circumstance. It generates new lobe profile and calculates automatically the flow rate and flow rate irregularity according to the lobe profile generated. Results obtained from the analysis enable the designer and manufacturer of oil pump to be more efficient in this field.

• Tribology and Lubricants
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• v.36 no.2
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• pp.64-67
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• 2020

In the conventional gerotor design, the circular arc tooth of the outer rotor is first introduced, and then the inner rotor profile is generated by simulating the outer rotor motion while the inner rotor is fixed. The profile generation of tooth meshing exhibits relativity; therefore, the outer rotor profile can be generated by the movement of the inner rotor. In this study, we propose the design of a gerotor with a pin-tooth inner rotor. First, the pin-tooth inner rotor is devised, and then the outer rotor profile is generated. The profile of the inner rotor is simply composed of equally arranged pins along a circle. The root of the inner rotor is designed as a conjugated arc of two pins. The trajectory of the pin center is obtained by the inner rotor operation, and then the outer rotor profile is determined as a parallel curve of the trajectory. In this gerotor design, the inner rotor has a simple configuration, and contact occurs between the pin parts of the inner rotor and the whole profile of the outer rotor. This affects the material selection and machining process. The pin tooth can be used to design the outer and inner rotors, enabling a double gerotor mechanism corresponding to a planetary gear system.

• Journal of Drive and Control
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• v.16 no.4
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• pp.80-86
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• 2019

The gerotor type device is mainly used in low-speed, high-torque hydraulic motors, and is also applied as a small priming hydraulic pump. For this reason, many studies have been conducted to increase the efficiency of the gerotor pump. In this paper, we propose a new tooth profile design method different from the existing method. The new tooth design is made by modifying the tooth surface using the amplification function of the trajectories, created along the inner and outer rolling circles around the base circle. The shape of the mate rotor is then created using rotation simulation techniques. Such shapes are described as hypercloid. The designed hypercloid rotor is compared with the existing trochoid rotor, and the characteristics of the parameters and volumetric displacements are analyzed. Through this process, the optimum design with larger volumetric displacement than the existing rotor is achieved.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.1
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• pp.120-129
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• 2009

An internal lobe pump is suitable for oil hydraulics of machine tools, automotive engines, compressors, constructions and other various applications. In particular, the pump is an essential machine element of an automotive engine to feed lubricant oil. The subject of this paper is the theoretical analysis of internal lobe pump whose the main components are the rotors: usually the outer one is characterized by lobes with elliptical shape, while the inner rotor profile is determined as conjugate to the other. And the integrated system which is composed of three main modules has been developed through AutoLISP under AutoCAD circumstance. It generates new lobe profile and calculates automatically the flow rate and flow rate irregularity according to the lobe profile generated. Results obtained from the analysis enable the designer and manufacturer of oil pump to be more efficient in this field.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.8
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• pp.1057-1067
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• 2010

Vibration and noise analysis as well as strength of gear teeth, gear profile design are considered in order to develop the multi-gear train devices of synchro system for the guns of a warship. A new approach to the critical speed calculation of practical industrial multi-mesh geared system is presented. A transfer matrix model based on Hibner's branch method is developed and the natural properties of the branched rotor system are calculated with using the ${\lambda}$-matrix formulation. A Campbell diagram, in which the excitation sources caused by the mass unbalance of the rotors and the transmitted errors of the gearing are considered, shows that, at theoperating speed, there are not the critical speed.