• Journal of Advanced Marine Engineering and Technology
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• 제26권2호
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• pp.200-208
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• 2002

The flash temperature of the cam-roller contacting surface for a marine diesel engine was analysed numerically. The elastohydrodynamic lubrication pressure and film thickness were adopted to get more accurate frictional coefficient, heat flux and temperature distribution. The maximum flash temperature was increased with both the increasing slip ratio of the contacting surfaces and increasing external load. This study tells that the temperature analysis is an indispensable procedure in designing elastohydrodynamic lubrication contacts on which the slip occurs.

• 한국생산제조학회지
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• 제19권6호
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• pp.739-745
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• 2010

The roller gear cam can control the rotational follower periodically by attaching several roller on the circumstance of follower shaft and it is widely used in non-backlash and precise actuating mechanism such as index table or ATC of machine tools. For machining the roller gear cam, 5 axis CNC machine tool is used and the geometric principle of CAM mechanism must be adopted to generate the NC-code and to develop the special CAD/CAM software because there is not commercial CAM system to machine the roller gear cam. The maker of the specially developed software in domestic user is generally from Japan or Taiwan. However these softwares do not reflect the post processing technique for finish machining in the module. Also, there is some limitation for further new application of itself and it needs higher costs for further application. In this study, the CAD/CAM software to overcome these problem was developed. And its reliability was verified by applying it in 5-axis CNC machining. Finally, the experimental result conducted in the 5-axis machining show good consistency in the movement of follower along the flute and in its Size.

• Tribology and Lubricants
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• 제26권1호
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• pp.56-60
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• 2010

Contact pressure occurs whenever two surfaces contact between cam and roller. Especially excessive pressure peaks occur at the ends of the contact region. Such as scuffing or pitting will be induced when these operating conditions continuously occur on the surface. Camber effect is given to reduce damage by changing the shape of roller. The objective of this paper is to calculate contact pressure distribution by using a contact analysis considering camber and tilting angle. These results predict that camber effect of all machine components have influence on contact pressure distribution.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.612-615
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• 2000

Cam mechanism is one of the common devices used in many automatic machinery. Specially cylindrical cam generates three dimensional motions. Thus, the shape design procedures must have high accuracy. This paper proposes the shape design procedure for a cylindrical cam and follower mechanism using a relative velocity method. The relative velocity method and the coordinate transformation are used to find a contact point between the cam and the follower. Also, the full shape of the cylindrical cam can be generated by using the geometric relationships and the contact constraints. As a result, this paper presents an example for the shape design of the cylindrical cam in order to prove the accuracy of the design procedures.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.168-172
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• 2001

The subsurface stress field beneath the roller due to the lubricant film pressure acting on the roller surface has been calculated. Main purpose of this study in view of engineering is to prove the validity of the numerical profile roller presented by Koo et al who obtained the lubricant film pressure by elastohydrodynamic lubrication analysis on the cam-roller mechanism. The stress field for the numerical profile roller was compared with the one for the existing dub-off profile roller.

• Journal of Advanced Marine Engineering and Technology
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• 제26권2호
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• pp.174-180
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• 2002

The subsurface stress field beneath the roller's contacting surface due to the contact pressure in lubricating condition has been calculated. Main purpose of this study in view of engineering is to prove the validity of the numerical profile roller presented by Koo et al. The Love's rectangular patch solution was used to obtain the subsurface stress field. The stress field of the numerical profile roller was compared with the one of the existing dub-off profile roller The analysis results show reduced subsurface stresses for the numerical profile roller.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.487-491
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• 2001

In this paper, we developed an automated program for the modeling and manufacturing of three-dimensional roller gear cams. A computer program employing the theory of gearing and coordinate transformation is developed for synthesizing and animating cam mechanisms. Then a module for generation NC program for a five-axis CNC machine to manufacture roller gear cam is established.

• 대한기계학회논문집A
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• 제34권3호
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• pp.361-367
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• 2010

3 차원 캠의 하나인 배럴캠은 자동화 생산 기계에서 인덱스 드라이브 유닛의 부품으로 많이 사용된다. 캠의 회전축과 종동절의 회전축이 90 도의 위상으로 직교한다. 인덱스 드라이브는 일정한 속도로 회전하는 캠의 입력에 대해 회전하고 정지한다. 터렛이 배럴캠의 회전에 의해 작동하는 동안 종이컵이 매우 빠르고 정확하게 성형된다. 그러나, 배럴캠과 종동절사이의 지속적인 미끄럼 접촉에 의해 점착마모가 발생하며 이러한 마모는 시스템의 성능에 영향을 준다. 결과적으로 제품의 불량율을 증가시킨다. 본 연구에서는 종이컵 성형기에 사용되는 배럴캠의 마모에 영향을 주는 인자가 접촉력임을 확인한다. 배럴캠과 롤러 사이의 접촉력은 다물체 동역학 모델을 이용해 계산한다. 그리고 해석 결과와 실제 시스템의 마모부와 비교를 통해 중요 마모 인자가 접촉력임을 검증한다.

• 대한기계학회논문집A
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• 제35권4호
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• pp.433-438
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• 2011

종이컵 성형기는 배럴캠, 인덱스, 터렛, 모터 등의 많은 부품으로 이루어진다. 그 중에서 배럴캠은 기계의 주 구동부이다. 배럴캠이 회전하면서 인덱스에 고정되어 있는 롤러를 밀어준다. 그리고 인덱스와 연결된 터렛이 회전하면서 종이컵이 만들어진다. 따라서 종이컵 성형기의 성능은 배럴캠에 큰 영향을 받는다. 이번 연구에서는 배럴캠을 설계하는 프로그램이 MATLAB 을 이용하여 개발 되었다. 프로그램은 배럴캠의 프로파일을 만들어준다. 이 프로파일은 3 차원 CAD 프로그램을 이용 하여 3 차원 CAD 모델로 변환된다. 이 3 차원 CAD 모델과 배럴 캠의 3 차원 레이저 측정을 통해 생성된 모델을 포함하는 동역학 모델을 생성하였다. 그리고 동역학 모델을 검증하기 위해 기계의 인덱스의 회전각이 고속카메라를 이용하여 측정된다. 동역학 모델의 회전각을 비교하여 프로그램을 검증한다.

• 대한기계학회논문집A
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• 제26권8호
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• pp.1527-1533
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• 2002

When a mechanism transfers a motion to an intersected shaft, a cylindrical cam mechanism may be the best choice among the mechanisms. The cylindrical cam with a roller follower provides to transfer the motions to the intersect shafts simply without other connecting equipments of the intersect shafts. Typical example may be a roller-gear-cam mechanism. But the shape of the cam must be exactly defined in order to satisfy the conditions for the prescribed motion of the follower. This paper proposes a new method for the shape design of the cylindrical cams and also a CAD program is developed by using the proposed method. The relative velocity method calculates the relative velocity of the follower versus the cam at a center of roller, and then determines a contact point by using the geometric relationships and the kinematic constraints. The constraint used in the relative velocity method is that the relative velocity must be parallel to a common tangent line at the contact point of two independent bodies, i. e. the cam and the follower. Then, the shape of the cam is defined by the coordinate transformation of the trace of the contact points. Finally, this paper presents an example in order to prove the accuracy of the proposed methods in this paper and the application of the CAD program"CamDesign".