• Clinics in Shoulder and Elbow
• /
• 제18권2호
• /
• pp.91-95
• /
• 2015

Background: Our aim was to make a comparative analysis of radiological and clinical outcomes of using either one or two interlocking distal screws on a Polarus intramedullary nail for the internal fixation of humeral shaft fractures. Methods: From January 2008 to March 2014, we enrolled 26 patients with humeral shaft fractures who were operated on using intramedullary nails. The patients were divided into 2 groups according to how many interlocking distal screws were used to lock the Polarus nail: in group 1, a single interlocking distal screw was used in 12 patients; and in group 2, double interlocking distal screws, in 14 patients. We compared the degree of recovery of the displaced fracture fragments between the two groups. To compare the nonunion and shoulder function, we assessed each patient's modified American Shoulder and Elbow Surgerns (ASES) score. Results: We found that 10 of 12 fractures achieved union in group 1, and 13 of 14 fractures, in group 2. We did not find a meaningful difference in the time to bone union between the two groups. The percentage of recovery of displaced fracture fragments until union was 66.9% for group 1 and 59.41% for group 2. At the final follow-up, we found that the scores for shoulder joint modified ASES was 78.7 for group 1 and 80.7 for group 2. Conclusions: Our results show that if locked appropriately, even a single screw on a Polarus nail can provide satisfactory radiological union and improved clinical outcome after intramedullary nailing of humeral shaft fractures.

• Journal of Korean Orthopaedic Sports Medicine
• /
• 제5권1호
• /
• pp.63-68
• /
• 2006

Purpose: To assess the effectiveness of the Locking compression plate (LCP) after open reduction for the treatment of the displaced clavicular shaft fracture, the clinical and radiologic outcome of the patients who were managed with the LCP for internal fixation after open reduction has been analyzed. Materials and Methods: We reviewed 26 cases with a displaced clavicular shaft fracture treated by internal fixation using Locking compression plate after open reduction between May 2003 and November 2004. The patients were followed up for at least six months period, and final postoperative outcome was evaluated using clinical results based on Kang's criteria, radiologic signs of fusion. Results: All fractures united by an average of 9.3 weeks without delayed union and showed fast recovery of motion fraction and shoulder function. In addition,24 cases without the fractures of proximal humerus recovered to normal range of shoulder notion within 2.9 weeks. Clinically, according to Kang's criteria, the outcome was good or better in 22 patients. The complications included shoulder joint dysfunction in two cases and keloid formation in one case, and no other complications were observed. Conclusion: The internal fixation using LCP for the treatment of displaced clavicular shaft fracture is a safe, reliable method of treatment, with few complications, and offers rapid recovery of shoulder joint function and bone union.

• Journal of the korean Society of Automotive Engineers
• /
• 제3권3호
• /
• pp.1-7
• /
• 1981

재래적 자동차의 구동계통은 동력원 즉 engine이 앞에 위치하고 뒤에서 미는 순서로 되어 있다. 그러므로 engine 과 차축을 연결하는 이 축(또는 구동계통)은 engine으로 부터의 힘을 차축으로 전달하는 역할을 하며 기본적으로 비틀상태의 반성부재로서 비교적 큰 회전 insertia를 받게 된다. 구동축은 한 개 또는 그 이상의 universal joint와 solid 상태 또는 관으로 된 축으로 조립 되어 있다. 그리하여 축방향의 동작을 통해서 토오크를 전달하고 일정한 각도 또는 변화되는 각도에서 회전운동을 한다. 차축은 차체 spring을 통해서 부쳐져 있으므로 주행중 구동축은 축 방향의 길이의 변화가 있게 되며 따라서 연결돤 각동작이 일어나며 이를 위해서는 universal joint가 필요하게 되며 따라서 전륜구동차에서도 필요하다. 자동차에 적용되고 있는 구동적에는 두가지 기본형이 있는데 torque tube형 구동방법과 hotchkiss형(또는 open driveline형) 구동방 법이다. Torque tube형 구동방식은 근래에는 사라져 가고 있는데 그 주요원인은 구동계통에서 발생되는 소음이 튜브를 통해 증축 전달되며 수리비용이 비교적 큰 때문이다. 이에 비해 open driveline형의 이점은 제조원가가 낮고, 용이하게 제조할 수 있으며, 종량이 경강되며 장착하기 에도 용이한 점들이다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 한국소성가공학회 2005년도 춘계학술대회 논문집
• /
• pp.283-286
• /
• 2005

Because CV Joint which is one of the component of automobile power train system communicates high power and performs power steering function, it requires high qualities such as high strength, high toughness and high fatigue resistance. This component undergoes a series of production processes such as forging, machining and heat treatment and required properties for this component depends on plastic deformation and heat treatment heavily. Therefore in this study, in order to these effects on mechanical properties due to plastic deformation and heat treatment we performed heat treatment following plastic deformation and then tensile test.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• 제12권12호
• /
• pp.929-934
• /
• 2002

This paper considers the vibration Problem of vehicle driveline which consists of two propeller shafts and the center bearing. The excessive vibration occurs at the center bearing when the vehicle starts to run. Using the kinematic constraints at the universal joint between two propeller shafts, we developed an one d.o.f model which describes the radial motion of the center bearing. We found out that the vibration occurs at the specific vehicle speed corresponding to the natural frequency of the model. Comparing the simulation results with test results we also show that the vibration at low vehicle speed is caused primarily by the feint angle and secondarily by the mis-aligned yoke flange rather than by the unbalance.

• Clinics in Shoulder and Elbow
• /
• 제16권1호
• /
• pp.27-32
• /
• 2013

Purpose: The purpose of this study is to evaluate the clinical and radiological outcomes of treatment of humerus shaft simple fracture by minimally invasive percutaneous osteosynthesis (MIPO) technique using locking compression plate (LCP). Materials and Methods: Six patients who were operated for humerus shaft simple fracture from August 2010 to May 2011 were enrolled for this study. We checked the cause of injury and the accompanying injuries and evaluated the operation time, the clinical and radiological period of union, postoperative range of motion of the shoulder and elbow joint, pain, activities in daily living, radiologic alignment, and other complications. Results: The clinical period of bone union was 7.2 weeks on average, and the radiologic period of bone union was 8 weeks on average. Follow-up period was more than 12 months in all cases. The angulation through postoperative alignment was 2.8 degrees in AP view and 2 degrees in lateral view. The postoperative range of motion was 167 degrees in forward flexion, 50 degrees in external rotation, and thoracic vertebra 12 level in internal rotation. The average value of visual analogue scale (VAS) was 1.2 and that of KSS was 91.3. The American Shoulder and Elbow Surgeons' score (ASES) was 26.5 and the UCLA score was 31.5. Conclusion: MIPO technique for the humerus shaft simple fracture showed good functional and radiological outcomes and may be considered as one of the treatment options for humerus shaft simple fracture.

• Journal of the Korean Society for Heat Treatment
• /
• 제34권6호
• /
• pp.309-314
• /
• 2021

Due to the superior corrosion resistance and mechanical properties of TiAl alloy at high temperature, it has been utilized as a turbine wheel of a turbocharger. The dissimilar metallic bonding is usually applied to combine the TiAl turbine wheel with the SCM440 structural steel which is used as a driving shaft. In this study, the TiAl and SCM440 joint were fabricated by using a friction welding technique. During bonding process, to suppress the martensitic transformation and the formation of cracks, which might reduce a strength of the joints, Cu was used as an insert metal to relieve stress. As a result, the intermetallic compounds (IMCs) layer was observed at TiAl/Cu interface while no IMC formation was formed at SCM440/Cu interface. Since understanding of the IMCs effects on the mechanical performance of welded joint is also essential for ensuring the reliability and integrity of the turbocharger system, we estimated the nanohardness of welded joint region through nanoindentation. The relation between the microstructural feature and its mechanical property is discussed in detail.

• Journal of Power System Engineering
• /
• 제6권3호
• /
• pp.36-41
• /
• 2002

A swashplate type piston motor with a tripod joints is introduced to improve compactness and starting torque in conventional types of motor. If the driving torque of motor shaft is transmitted by utilizing the mechanism, its friction torque loss would be drastically reduced and mechanical efficiency would be improved because the lateral force on the piston of the rod type motor with tripod joints mechanism is relatively smaller than that of the conventional plunger type motor. In particular, kinematics analysis for the mechanism are done as a preliminary study to investigate the feasibility of the mechanism in the axial piston motor. General formulas are derived from the displacement and velocity analysis of the mechanism, showing relationships between output shaft and shoe holder motion. A series of numerical calculations are carried out for a medium size motor with 160cc/rev using the formulas and their graphical plots are shown as well.

• Journal of the Korean Society for Precision Engineering
• /
• 제15권7호
• /
• pp.139-148
• /
• 1998

Internal and external heat sources will cause to deform to machine elements in the contact joint of structure, which results in the change of contact pressure distribution different from initial assembly. Heat induced variations of contact pressure will change the static and dynamic properties such as contact stiffness, damping as well as contact heat conduction in the structure In order to design and control the intelligent machine tool operating in variant conditions more sophisticatedly, the good prediction for the changes of prescribed properties are strongly required especially in the contact elements adjacent to the rotational or linear bearing. This paper presents some computational and experimental results in regard to static and dynamic characteristics of the press-fitted bush and shaft assembly which is a model of the bearing innerrace and shaft assembly. In the condition of heat generation on the outer surface of the bush, the effects of changes in the negative clearance and the heat flux on pressure distribution and dynamic properties are investigated. Results of this study show that the edge effect of the bush and the initial clearance have effects on the transient dynamic characteristics significantly.

• Clinics in Shoulder and Elbow
• /
• 제24권3호
• /
• pp.183-188
• /
• 2021

We report a case of a 69-year-old right-dominant man who had an open Monteggia-like lesion of the right elbow (Gustilo-Andersen IIIA) with severe proximal ulna bone loss associated with an ipsilateral ulnar shaft fracture due to a motorcycle accident. The patient underwent two-stage surgery. Wound debridement and bridging external fixation were performed at first. Three months later, a frozen massive osteochondral ulnar allograft was implanted and fixed with a locking compression plate. A superficial wound infection appeared 5 weeks after the second surgery. Superficial wound debridement, negative pressure therapy, and antibiotics were administered for 3 months, achieving infection healing. At 3 years post-surgery, the elbow range of motion was satisfactory with a Disabilities of the Arm, Shoulder and Hand (DASH) score of 16.7. Radiographs and computed tomography scans showed good allograft-bone integration without allograft reabsorption or hardware loosening. Although not complication-free, massive ulna osteochondral allograft implantation can be considered a valid option in cases of open Monteggia-like lesions associated with ulnar shaft fracture and severe bone loss in active patients, whenever osteosynthesis or joint replacement is not a proper solution. This type of bone stock restoration allows for future surgery, if needed.