차동복합 유성기어 감속 시스템의 기어 강도에 관한 안전성 분석

강진경(Jin-Gyeong Kang),유영락(Young-Rak Yoo),박규태(Kyu-Tae Park),류성기(Sung-Ki Lyu) 한국기계가공학회 2024 한국기계가공학회지 Vol.23 No.3

This study calculated the actual bending and surface pressure stresses of the gears of a differential compound planetary gear reduction system with a high reduction ratio and determined the allowable stress values of the material from an S–N curve. The safety factor was derived by comparing the allowable bending and surface pressure stress calculation results with the allowable stress of the material. A comparison of the allowable stress values of the material and the calculated bending and surface pressure stresses of the gears confirmed that the gears of the differential composite planetary gear reduction system were structurally safe.

고 감속 차동 복합 유성기어 감속 시스템의 구조 안전성 분석

강범준(Beom-jun Kang),유영락(Young-Rak Yoo),박규태(Kyu-Tae Park),김재범(Jae-Beom Kim),정동헌(Dong-Heon Jeong),신슬기(Sul-Gi Shin),이지환(Ji-Hwan Lee) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.4

해상 물류 시스템 장비, 대형 산업 장비 및 건설 중장비의 높은 초기 기동 토크에 대응하기 위해 유압식 감속 시스템 모듈이 적용되고 있다. 감속 시스템의 구조는 회전력을 발생하는 유압 모터와 회전하는 구동 축을 감속하는 유압 브레이크, 그리고 회전력을 일정한 비율로 감속하고 동력을 전달하는 유성기어 감속기로 구성된다. 본 연구에서는 기존의 다단 유성기어 감속 방식에서 10%이상의 부품 수 감소와 5% 이상의 소형화 및 경량화가 가능한 차동 복합 유성 감속기를 제시하고 있으며 설계 조건으로 DNV Standard 2.22 규격을 적용하였다. 감속 시스템 기어 류에 대해 Lewis 와 Hertz 이론 기반의 굽힘 응력과 면압 응력을 산출하였고 상용 FEM 구조 해석 프로그램을 통해 구조적 안전성을 분석하였다. In order to cope with the high initial starting torque of marine logistics system equipment, large industrial equipment, and heavy construction equipment, hydraulic reduction system modules are being applied. The structure of the reduction system is composed of a hydraulic motor that generates rotational force, a hydraulic brake that decelerates the rotating drive shaft, and a planetary gear reducer that decelerates the rotational force at a constant rate and transmits power. In this study, a differential compound planetary reducer capable of reducing the number of parts by more than 10%, miniaturization and weight reduction by more than 5% in the conventional multi-stage planetary gear reduction method is proposed, and DNV Standard 2.22 standard is applied as a design condition. Bending stress and surface contact stress based on Lewis and Hertz theory were calculated for gears in the reduction system, and structural safety was analyzed through a commercial FEM structural analysis program.

80cc 사축식 유압 모터용 2속 유성기어 감속 시스템의 이뿌리 굽힘응력 해석

강진경(Jin-Gyeong Kang),유영락(Young-Rak Yoo),박규태(Kyu-Tae Park),류성기(Sung-Ki Lyu) 한국기계가공학회 2023 한국기계가공학회지 Vol.22 No.8

카이모파페인에 의한 요추추간판 탈출증 효소치료에 대한 임상적 연구

하영일,유영락,정환영 한양대학교 의과대학 1986 한양의대 학술지 Vol.6 No.1

The intradiscal injection of chymopapain has been performed for the treatment of lumbar disc herniation in 490 patients since 1984. The patients were examined with CT, CTMM and oil or water - soluble myelography as well as neurological examination. The discography was performed in every case only to observe whereabouts of the contrast medium. Under the aid of the fluoroscopic image intensifier, posterolateral discographic needling was performed with double needle technique using a short 18-gauge and long 22-gauge needle. Following results were obtained. 1) Follow-up of 420 cases showed excellent in 188 cases (44.88%), good in 172 cases (40.9%), fair in 50 cases (11.9%) an unchanged in 10 cases (2.4%), respectively. 2) There are good results in chemonucleolysis on three or four interspaces as well as one or two interspaces. 3) The history of previous surgical discetomy was not a contraindication as long as routine procedure was strictly undertaken. 4) The spine CT is preferable to other diagnostic studies for evaluation of hernated lumber disc. 5) The postinjection-spinal-instability developed in 392 (80%) of the 490 cases for three to four days but it disappeared within 1 week. 6) In discography, there are epidural leak in 82 cases (19.5%) of patients but were not related with the outcome of the chemonucleolysis. 7) 274 cases (90%) showed the narrowing of the intervertebral disc space at 3 monts after chemonucleolysis. 8) Lumbar chemonucleolysis has been performed in 490 cases without serious complications such as anaphylaxis and/or immediate profound hypotention. In conclusion, lumbar chemonucleolysis with chymopapain was very useful under strict precaution.

요추에 발생한 Ewing's Sarcoma 1례 : 증례보고 Case Report

하영일,조해동,유영락,김남규,정환영,김춘원 대한신경외과학회 1981 Journal of Korean neurosurgical society Vol.10 No.2

Ewing's sarcoma is an uncommon malignant neoplasm of the bone, which is rather infrequent in childhood and represented only 2% of all neoplasm under the age of IS years. Clinical picture was that of progressive paraplegia associated with localized pain. The authors have experienced a case of primary Ewing's sarcoma of the first and second lumbar vertebrae in a 26-year-old male.

자발성 뇌내출혈의 수술적 치료

김영준,오석전,유영락,김남규,정환영 대한신경외과학회 1986 Journal of Korean neurosurgical society Vol.15 No.3

The authors operated 127 cases of the spontaneous intracerebral hematoma patients who were admitted via the emergency room during the recent two years. The location, timing of operation, method of approach, mortality etc. were analyzed. The results are as follows: 1) putaminal hemorrhage was 47.3%, thalamic hemorrhage was 23.6%, subcortical hemorrhage was 18.9%, cerebellar hemorrhage was 3.9%, pontine hemorrhage was 1.6%, and IVH only was 4.7%. 2) 77.2% was operated during the first 48 hours from the onset. 3) Almost all of the procedures were transcortical and trans-sylvian approach. 4) The mortality rate was 52.0%. 5) Microsurgical technique and external ventricular drainage (or ventriculoperitoneal shunt) played an important role for the good surgical outcome.

요추 추간판 탈출증 812수술례에 대한 임상적 고찰

하영일,조해동,유영락,김남규,정환영 대한신경외과학회 1981 Journal of Korean neurosurgical society Vol.10 No.2

The purpose of this study on the surgical results for lumbar intervertebral disc herniation is to analyze the unique feature of the series which seems to be sufficient to represent Korean patients suffering from these diseases. A total of 812 lumbar discectomies had been performed from May, 1972 to December, 1978 at Hanyang University Hospital. The most outstanding unique feature was the level of the lesion. The L₄-L_(5), interspace was affected in 87.6%. while the most of the other series showed almost same incidence between L₄-L_(5), and L_(5)-S₁, interspaces. The results of this analysis are as follows: 1) The incidence ratio of male to female was 1.3: 1. 2) Most were in the 4th and 5th decade (53.5%). The duration was over one year in 64.6% of cases. 3) Traumatic origin was 37.8% of cases. Post-delivery, convulsive and unknown etiology were 2.2%, 0.7% and 59.3% of cases, respectively. 4) The level of the lesion was predilected at L₄-L_(5) interspace with the incidence of 87.6%, while L_(5)-S₁, interspace was affected in 25.4% of cases. Single lesions were 70.8% and the multiple 29.2% of cases. 5) False positive findings of myelogram were 1.2% of cases. 6) Surgical results were gratifying in 92.3% of cases. 7) The incidence of postoperative complications was 3.3% of cases, which were mainly stitch abscesses. 8) The 7 out of 812 cases were associated with spinal tumors.

엑스선 단순촬영상에 나타난 한국 정상 성인 척추관의 상관계수 측정

김대규,박중겸,유영락,김남규,정환영 한양대학교 의과대학 1982 한양의대 학술지 Vol.2 No.2

The range of normal values of the spinal canal index of 180 normal Korean adults was measured in cervical and lumbar region. The purpose of this study was to establis the range of normal values of anteroposterior spinal canal index and lateral spinal canal index in cervical and lumbar region in the interest of facilitating clinical investigation of spinal canal stenosis. The anteroposterior spinal canal index was obtained by measurement of the ratio of the interpedicular distance to the transverse diameter of the vertebral body, and lateral spinal canal index was obtained by mesurement of the ratio of the sagittal diameter of the spinal canal to the anteroposterior diameter ofthe vertebral body. The results were the followings: 1. The lateral cervical spinal canal index from third to seventh cervical vertebra in male were 1.15±0.15 (mean±standard deviation), 1.16±0.17, 1.12±6.16,1.14±0.16, 1.15±0.12 repectively, and in female were 1.10±0.12, 1.11±0.13, 1.08±0.14, 1.08±0.13, 1.11±0.11 repectively. In male and female combined, those were 1.13±0.14, 1.14±0.16, 1.10±0.10, 1.12±0.15, 1.13±0.12 respectively. The mean of lateral cervical spinal canal index in male were larger than in female, and smallest in fifth cervical vertebra. 2. The anteroposterior lumbar spinal canal index from first to fifth lumbar vergbra in male were 1.81±0.16, 1.84±0.16, 1.87±0.15, 1.90±0.17, 1.83±0.17 repectively, and in female were 1.66±0.13, 1.71±0.14, 1.76±0.16, 1.79±0.14, 1.78±0.14 respectively. In male and female combined, those were 1.74±0.16, 1.78±0.16, 1.81±0.16, 1.85±0.16, 1.81±0.16 respectively. The mean of anteroposterior lumbar spinal canal index in male were larger than in female, and larger in lower lumbar region than in upper lumbar region relatively. 3. The lateral lumbar spinal canal index from first to fifth lumbar vertebra in male were 1.77±0.16, 1.78±0.17, 1.84±0.17, 1.90±0.15, 1.96±0.20 respectively, and in female were 1.72±0.18, 1.72±0.16, 1.77±0.13, 1.86±0.16, 1.95±0.18 respectively. In male and female combined, those were 1.75±0.17, 1.75±0.17, 1.81±0.16, 1.88±0.15, 1.96±0.19 respectively. The mean of lateral lumbar spinal canal index in male were larger than in female, and larger in lower lumbar region than in upper lumbar region relatively. The lumbar canal to body ratio were obtained by multiplication of anteroposterior spinal canal index by myltiplication of anteroposterior spinal canal index by lateral spinal canal index. Compared with the measurements of Jones and Thoson, Lusted and Keats, Kang, et al., there was no apperent difference in the mean and distribution pattern between the orientals and the westerners.

뇌질환에 대한 초음파의 진단적 가치

김형규,오석전,조해동,유영락,김남규,정환영 대한신경외과학회 1984 Journal of Korean neurosurgical society Vol.13 No.4

We analysed ultrasonic findings of 54 brain scan cases (45 cases were performed through the anterior fontanelle and the temporoparietal thin bone and 9 through the surgical bone defect) and comparison of these pictures with those obtained in the same patients by CT scan showed prominent correlation. Ultrasonography was more sensitive to different histologic features and provided a more accurate depletion of the neuropathologic characteristics in most of cases. We conclude that ultrasonography of the brain was proven to be quite useful in the screening and follow up of neonates and infants under 15 months of age, and as a follow up method in post operative patients. It was also more accurate than CT scan in cases of abscesses and cystic lesions.

경추 및 요추 추골체간 골융합용 소뼈 골 제품 (Bovine bone) 사용경험 : A preliminary report

김주승,이언,오석전,조해동,유영락,김남규,정환영 대한신경외과학회 1983 Journal of Korean neurosurgical society Vol.12 No.4

The authors experienced on the use of bovine bone in 3 cases of interbody fusion employing the Cloward technique. Two patients were cervical fracture-dislocation and one patient was a case of lumbar spondylolysis. With use of bovine bone, iliac osteotomy is unnecessary, and this procedure is no problem of donor site pain and infection which can be possible in interbody fusion with iliac bone and rib graft. With the use of bovine bone the additional advantages are, 1) The operative procedure is simplified. 2) The time required for the operation is diminished. 3) Patient meralgia is eliminated completely. 4) The surgeon can have uniformly sized bones of a proven hardness on hand. 5) The epidural bleeding is showed through lattice of bovine bone.