• 대한족부족관절학회지
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• 제24권2호
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• pp.98-101
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• 2020

We report on the case of a patient with chronic instability of the ball-and-socket ankle joint. The patient, a 21-year-old male, was diagnosed 10 years previously with chronic instability of the ball-and-socket ankle joint. He underwent Broström procedure and augmentation using a periosteal turn down from the fibula for this chronic instability despite having received conservative treatment since the diagnosis. After the procedure, the clinical symptoms of ankle instability were improved and the patient is being periodically followed-up. We report on this case of using a Broström procedure as a treatment option for patients with instability of the ball-and-socket ankle joint with normal range of foot and normal ankle joint alignment without damage in the joint and cartilage.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제25회 추계학술대회논문집
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• pp.40-45
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• 2005

현재까지 적용되고 있는 추력제어 장치로는 크게 노즐의 확대부에 장착되어 화염의 방향을 조종하는 제트베인(jet vane), 제트탭(jet tab)방식과 노즐자체를 회전하는 방식인 볼/소켓형(ball & socket) 노즐, 플렉시블 씰형 (flexible seal)노즐로 구분된다. 본 연구는 노즐자체를 회전하여 추력방향을 제어하는 볼/소켓형(ball & socket) 노즐이 회전할 경우 발생되는 유입부의 비대칭성이 노즐 성능에 미치는 영향을 예측하기 위하여 수행한 3차원 수치해석결과와 공압시험 결과를 수록하였다. 유동해석 결과 유입부의 비대칭성이 유동에 미치는 영향은 노즐 목까지 점차적으로 줄어들고 하류 유동에 미치는 영향이 미비하였으며 해석된 주 추력의 크기는 시험에서 측정된 추력과 비슷한 경향을 나타내었으나 측 추력의 경우 시험 값보다 낮게 나타났다.

• 대한족부족관절학회지
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• 제9권2호
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• pp.231-233
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• 2005

Ball-and-socket deformity of the ankle joint is a rare entity that is usually associated with inequality of leg length, fibular hyperplasia, coalition of the ankle, and ray deficiency. Etiology is unknown, congenital itself or secondary to congenital conditions in the ankle. Nonunion of medial malleolar is rare in bilateral ball and socket ankle joint without lower leg deformity. We report upon this case, and include brief reviwe of the literature.

• 소성∙가공
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• 제16권2호
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• pp.132-137
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• 2007

A double roll rotary forming equipment is presented in this paper. The equipment is developed for joining the socket with the ball of a concave piston assembly with its geometrical tolerance requirements satisfied. The equipment is composed of a lathe, a double roll system and a roll pressing unit driven by the hydraulic system. The workpiece rotates by spindle chuck of the lathe while the double roll system approaches perpendicularly to the central line of the workpiece. The equipment is successfully applied to precision joining of the ball and the socket fur the concave piston assembly of a high pressure hydraulic pump.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1016-1021
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• 2004

The need for developing a mathematical model for pad-pivot friction in tilting pad proceeding bearings has been well-recognized, since previous experimental work about the performances of the bearings hypothesized that the friction in the bearings is closely related to their performances. Especially, the sliding friction between pad and pivot in the ball and socket type of the bearings can influence the performance of the bearing. We propose a mathematical model for pad-pivot friction in the ball and socket type, which considers the geometrics of the pad and pivot of the bearings, by assuming the sliding friction in the ball and socket bearing as Coulomb friction. By utilizing the proposed model for pad-pivot friction, we show the analysis of Reynolds equation and energy equation, which explain the thermo-hydrodynamic characteristics of tilting pad proceeding bearings, by taking into account the turbulence and inlet pressure building as well. The results of the study show that the performance of titling-pad proceeding bearings can be greatly influenced by the pad-pivot friction. In particular, we have shown that the analysis of the pad-pivot friction is useful to explain the static proceeding loci and the dynamic characteristics of the ball and socket type of the bearings. Furthermore, for a given operating condition, we can obtain various equilibrium states which satisfy the static equilibrium conditions, by considering the pad-pivot friction.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.825-826
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• 2008

• 한국추진공학회지
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• 제10권2호
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• pp.46-52
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• 2006

현재까지 적용되고 있는 추력제어 장치로는 크게 노즐의 확대부에 장착되어 화염의 방향을 조종하는 제트베인(jet vane), 제트탭(jet tab)방식과 노즐자체를 회전하는 방식인 볼/소켓형(ball & socket) 노즐, 플렉시블 씰형 (flexible seal)노즐로 구분된다. 본 연구는 노즐자체를 회전하여 추력방향을 제어하는 볼/소켓형(ball & socket) 노즐이 회전할 경우 발생되는 유입부의 비대칭성이 노즐 성능에 미치는 영향을 예측하기 위하여 수행한 3차원 수치해석결과와 공압시험 결과를 수록하였다. 유동해석 결과 유입부의 비대칭성이 유동에 미치는 영향은 노즐 목을 지나면서 현저히 줄어들고 하류 유동에 미치는 영향이 미비하였으며 해석된 주 추력의 크기는 시험에서 측정된 추력과 비슷한 경향을 나타내었으나 측 추력의 경우 시험 값보다 낮게 나타났다. 또한 시험의 결과 기하학적으로 회전된 회전각에 의한 추력방향과 측정된 추력의 방향이 일치하지 않음을 알 수 있었다.

• 소성∙가공
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• 제16권6호
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• pp.479-487
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• 2007

Die life is generally estimated taking failure life and wear amount into consideration. In this study, the forging die life was investigated considering both of these two factors. The fatigue life prediction for the die was performed using the stress-life method, i.e. Goodman's and Gerber's equations. The Archard's wear model was used in the wear life simulation. These die life prediction techniques were applied to the die used in the forging process of the socket ball joint of a transportation system. A rigid-plastic finite element analysis for the die forging process of the socket ball was carried out and also the elastic stress analysis for the die set was performed in order to get basic data for the die fatigue life prediction. The wear volume of the die was measured using a 3-dimensional measurement apparatus. The simulation results were relatively in good agreement with the experimental measurements.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.353-358
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• 2006

A three-dimensional finite element approach to process analysis and design for joining the socket with the ball by a kind of the rotary forging processes is presented in this paper. The rigid-plastic finite element method is employed and its results are used to reduce the number of process design tryouts. The approach is applied to developing a concave piston assembly for a high pressure hydraulic pump. Experiments show that the developed piston assembly satisfies the quality requirement on geometrical tolerance.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 추계학술대회 논문집
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• pp.321-325
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• 2001

This paper describes the basic structure of high-precision warm forging process for ball joint socket. If this research is successfully finished, We expect that productivity improvement, reduction of material cost and machining process, and cost down than conventional warm forging process.