터보펌프용 커빅커플링의 개발

정은환(Eunhwan Jeong),윤석환(Suk Hwan Yoon),김진한(Jinhan Kim) 한국추진공학회 2009 한국추진공학회 학술대회논문집 Vol.2009 No.5

본 연구에서는 커빅커플링의 설계, 구조해석, 고온 비틀림시험 및 실형상 축-디스크를 제작/조립성 검토를 통해 터보펌프 터빈에의 적용 가능성을 타진하였다. 커플링의 치형은 Gleason 치형을 기본형상으로 하여 설계운용조건의 1.5배의 토크값을 기준으로 설계를 진행하였다. 구조해석 및 고온비틀림 시험을 통해 하중조건하의 안정성을 확인하였으며 특히 비틀림시험 후 커플링의 변형은 미미함을 확인하였다. 커빅커플링을 적용한 실형상 디스크 제작 및 조립시험을 통해 설계요구조건을 하회하는 디스크의 외주 및 축방향 흔들림 그리고 조립재현성을 확인하였다. Development of a curvic-coupling was presented in this paper. The research covers design, structural analysis, hot-temperature-torsion-test, curvic-coupling applied proto-type turbine disk manufacturing, and assembly test of a curvic-coupling rotor system for the turbopump application. Curvic-coupling was designed based on the Gleason-standard-tooth shape. The load capability of the designed curvic coupling was validated by the structural analysis and hot-temperature-torsion-test. A proto-type turbine disk which had adopted designed curvic-coupling was manufactured, assembled and tested to reveal that shaft-disk assembly run-outs in axial and radial directions were much smaller than the design requirements. The development will be finalized after spin test of shaft-disk assembly in near future.

Large Curvic Coupling Gear for Ultraprecision Angle Division Using FEM

Yoon-Soo Jung,Jia-Chen Gao,Gyung-Il Lee,Ku-Rak Jung,Jae-Yeol Kim 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.3

Curvic coupling is an important component used for ultraprecision machine tools in the machinery and aerospace industry. It plays an important role in accurate positioning of materials on the turret so that they can be precisely machined. However, all ultraprecision-360 T cube couplings used in Korea are imported from Japan. This study aims to examine how to use the FEM (Finite Element Method) for large curvic coupling gears for ultraprecision angle division. Commercial software CATIA is used for design, and ANSYS is used to analyze the large curvic coupling gear. In this study, a new type of large curvic coupling gear combining a large gear with curvic coupling is designed on the basis of the fitting equation as the allowable weight depends on the component size. Stress and friction were analyzed in consideration of external forces of the multipurpose precision angle division gear of the machine tool, and the maximum allowable external forces of the large curvic coupling gear for ultraprecision angle division were inspected. In general, numerical simulation can significantly reduce the time and cost for pilot production, and be used for various applications, as well as curvic coupling

탄소성 변형을 고려한 타이로드 고정 회전체의 동역학 해석

서동찬,김경희,이도훈,이보라,서준호 한국트라이볼로지학회 2024 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.40 No.1

This study conducts numerical modeling and eigen-analysis of a rod-fastened rotor, which is mainly used in aircraft gas turbine engines in which multiple disks are in contact through curvic coupling. Nayak's theory is adopted to calculate surface parameters measured from the tooth profile of the curvic coupling gear. Surface parameters are important design parameters for predicting the stiffness between contact surfaces. Based on the calculated surface parameters, elastoplastic contact analysis is performed according to the interference between two surfaces based on the Greenwood–Williamson model. The equivalent bending stiffness is predicted based on the shape and elastoplastic contact stiffness of the curvic coupling. An equation of motion of the rod-fastened rotor, including the bending stiffness of the curvic coupling, is developed. Methods for applying the bending stiffness of a curvic coupling to the equation of motion and for modeling the equation of motion of a rotor that includes both inner and outer rotors are introduced. Rotordynamic analysis is performed through one-dimensional finite element analysis, and each element is modeled based on Timoshenko beam theory. Changes in bending stiffness and the resultant critical speed change in accordance with the rod fastening force are predicted, and the corresponding mode shapes are analyzed. Keywords: Curvic coupling(곡률 커플링), Dual rotor(복 축), Rotordynamics(회전체 동역학), Contact mechanics( 접촉 역학), Elastoplastic deformation(탄소성 변형) Nomenclature An : Normal contact area of rough surface (m2) (거친 표면 수직 접촉 면적) †Corresponding author: Junho Suh Tel: +82-51-510-1475 E-mail: junhosuh@pusan.ac.kr http://orcid.org/0000-0001-5516-9637 ⓒ

복합공구대 디스크임계돌출거리와 절삭력과의 관계에 관한 연구

최지환(Ji-Hwan Choi),김재실(Chae-Sil Kim),조수용(Su-Yong Cho) 한국기계가공학회 2013 한국기계가공학회지 Vol.12 No.1

Curvic coupling of mill turret should maintain disk weight and the cutting resistance which occurs the machining operation and must also have power transmission function. In order to improve machining operation range, the ejecting distance from curvic coupling to the disk must increase as much as possible. But moment is increased by the lack of capacity of the curvic coupling. Increase of moment is the cause of vibration/noise and degradation of machining performance not only stability problem. The manufacturer of mill turret has no the design information between the ejecting distance and the cutting resistance with safety of curvic coupling. Therefore this study describes a finite element analysis model of mill turret using ANSYS workbench. The structural analyses and modal analyses with varying of the ejecting distances and cutting resistances are performed. Finally the equation for relationship between the critical ejecting distance and the cutting resistance is defined under 5 of the safety factor for the maximum von-Mises stress at the curvic coupling.

Curvic Coupling Tooth 가공의 연삭 조건 선정 및 가공면 평가에 관한 연구

허두권(Du-Kwon Hur),김명현(Myung-Hyun Kim),김찬규(Chan Kyu Kim),정영철(Young Cheol Jeong),정윤교(Yoon Gyo Jung),조영태(Young Tae Cho) 한국기계가공학회 2018 한국기계가공학회지 Vol.17 No.3

As gas turbines for power generation become increasingly more important for high capacity and high efficiency, the technological development and investment of companies are increasing globally. Gas turbine manufacturing technology is only owned by a few companies such as GE, Siemens, and MHI, and our country currently depends on imports of processing technology and component parts. The core part of the gas turbine is curvic coupling tooth processing technology that improves turbine efficiency by smoothly transmitting power to the turbine rotor. Curvic coupling tooth machining and evaluation research is restricted overseas, and it is not underway in Korea. Therefore, in this study, roughing and finishing process technology for curvic coupling tooth machining is developed and a quantitative evaluation method is proposed. For the development of machining technology, the analysis of critical parameters was performed through C & E analysis. In the roughing process, the conditions considering the minimum machining time and tool load ratio were determined. Finishing process conditions were determined based on the contact ratio between the tooth surfaces. The image-processing method is presented for evaluation of the contact ratio and a verification test was performed.

곡률 커플링 접촉각에 따른 접촉 강성 및 굽힘 강성해석

유용훈,조용주,이동현,김영철 한국트라이볼로지학회 2018 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.34 No.1

Coupling is a mechanical component that transmits rotational force by connecting two shafts. Curvic coupling is widely used in high-performance systems because of its excellent power transmission efficiency and easy machining. However, coupling applications change dynamic behavior by reducing the stiffness of an entire system. Contact surface stiffness is an important parameter that determines the dynamic behavior of a system. In addition, the roughness profile of a contact surface is the most important parameter for obtaining contact stiffness. In this study, we theoretically establish the process of contact and bending stiffness analysis by considering the rough surface contact at Curvic coupling. Surface roughness parameters are obtained from Nayak's random process, and the normal contact stiffness of a contact surface is calculated using the Greenwood and Williamson model in the elastic region and the Jackson and Green model in the elastic–plastic region. The shape of the Curvic coupling contact surface is obtained by modeling a machined shape through an actual machining tool. Based on this modeling, we find the maximum number of gear teeth that can be machined according to the contact angle. Curvic coupling stiffness is calculated by considering the contact angle, and the calculation process is divided into stick and slip conditions. Based on this process, we investigate the stiffness characteristics according to the contact angle.

하이브리드 커빅 기어 최적설계 및 IRT기법을 적용한 건정성 평가

이경일 ( Gyung-il Lee ),정윤수 ( Yoon-soo Jung ),김재열 ( Jae-yeol Kim ) 조선대학교 공학기술연구원 2016 공학기술논문지 Vol.9 No.4

The gear has played the important roles for long time as the one of representative mechanical elements together with bearing and screw since the industrial society. The gear not only plays the role of transmitting the power and is widely used as the one for the wrist watches in small size and turbine reduction gear for vessel in thousands of kw class, reduction device in automobile and aircraft, differential gear and wind power generator in large size but also its kind and usage are various even today. The gear that is developed in such various ways is developed to carry out the complex operations and its research and development are carried out in various types. The gear with such complex operations, special generation and shape is called as hybrid gear and its development is being carried out by the companies and academic society actively. Among these gears, hybrid CURVIC gear is an index of precision in machine tools in industrial society. In this paper, we prove the applicability and reliability of FEM analysis and infrared radiography for reliability improvement in hybrid CURVIC gear.

다구찌 방법을 적용한 Curvic Tooth형상가공에 대한 Contact Ratio최적화 연구

허두권(D. K. Hur),김명현(M. H. Kim),조영태(Y. T. Cho),정윤교(Y. G. Jung) 한국기계가공학회 2017 한국기계가공학회 춘추계학술대회 논문집 Vol.2017 No.4

An Analytical Study on the Thermal-Structure Stability Evaluation of Mill-Turn Spindle with Curvic Coupling

Choon-Man Lee(이춘만),Ho-In Jeong(정호인) 한국기계가공학회 2020 한국기계가공학회지 Vol.19 No.1

As demand for high value-added products with hard materials increases, the line center is used for producing high value-added products in many industries such as aerospace, automobile fields. The line center is a key device for smart factory automation that can improve the production efficiency and the productivity. Therefore, the development of a mill-turn line center is necessary to produce high value-added products with complex shapes flexibly. In the mill-turn process, a milling process and a turning process are combined. In particular, the turning process needs to increase the rigidity of the spindle. The purpose of this study is to analyze the thermal-structural stability through thermo-structural coupled analysis for a mill-turn spindle with a curvic coupling. The maximum temperature and thermal stability of the spindle were analyzed by thermal distribution. In addition, the thermal deformation and thermal-structural stability of the spindle were analyzed through thermo-structural coupled analysis.

공작기계용 Curvic Coupling 생산공정 및 검사용 치구 개발

박동근(Dong Keun Park),이춘만(Choon Man Lee),김재웅(Jae Woong Kim) Korean Society for Precision Engineering 2008 한국정밀공학회지 Vol.25 No.5