• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2009년도 춘계학술대회 논문집
• /
• pp.22-25
• /
• 2009

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.

• 한국정밀공학회지
• /
• 제25권5호
• /
• pp.28-33
• /
• 2008

• 한국기계가공학회지
• /
• 제12권1호
• /
• pp.110-116
• /
• 2013

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.

• Tribology and Lubricants
• /
• 제34권1호
• /
• pp.23-32
• /
• 2018

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.

• 한국기계가공학회지
• /
• 제17권3호
• /
• pp.87-92
• /
• 2018

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.

• Tribology and Lubricants
• /
• 제40권1호
• /
• pp.8-16
• /
• 2024

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.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2008년도 춘계학술대회 논문집
• /
• pp.823-824
• /
• 2008

• 한국기계가공학회지
• /
• 제19권1호
• /
• pp.100-107
• /
• 2020

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.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2011년도 제36회 춘계학술대회논문집
• /
• pp.7-11
• /
• 2011

75톤급 터보펌프용 속도복식 터빈을 개발하였다. 축과 로터의 연결에는 커빅커플링을 적용하였다. 커빅커플링은 시편을 통한 고온비틀림 시험과 시제품의 스핀시험을 통해 적용 적합성을 검증하였다. 고압 공기를 이용한 성능시험을 통해 개량형 속도복식 터빈의 비출력은 기본형 단단 터빈에 비해 설계점에서 20.5%가량 향상된 것으로 나타났다.

• 한국추진공학회지
• /
• 제15권3호
• /
• pp.40-46
• /
• 2011

75톤급 터보펌프용 속도복식 터빈을 개발하였다. 축과 로터의 연결에는 커빅커플링을 적용하였다. 커빅커플링은 시편을 통한 고온비틀림 시험과 시제품의 스핀시험을 통해 적용 적합성을 검증하였다. 고압 공기를 이용한 성능시험 결과, 개량형 속도복식 터빈의 비출력은 기본형 단단 터빈에 비해 설계점에서 20.5%가량 향상된 것으로 나타났다. 개량형터빈의 $1^{st}$로터는 설계점 전체출력의 74.1%를 담당하는 것으로 확인되었다.