• 제목/요약/키워드: Torque evaluation

검색결과 294건 처리시간 0.03초

토크 표준 및 평가 연구 동향 (Torque Standards and Evaluation)

  • 박연규;김민석;김종호;강대임
    • 한국정밀공학회지
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    • 제21권9호
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    • pp.26-31
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    • 2004
  • 일반적인 공업 제품은 다수의 부품들로 이루어져 있다. TV 등과 같은 가전제품은 천여개, 자동차는 만여개, 그리고 항공기는 십만여개의 부품으로 구성된다. 여러 개의 부품은 다양한 방법으로 조립되어 완제품을 이룬다. 자동차의 제조와 같은 기계공업 분야에서 가장 일반적인 조립방법은 볼트 또는 나사를 이용하는 방법이다.(중략)

토크 측정을 이용한 차량 변속기용 비틀림 진동 절연 댐퍼 평가 (Evaluation of Torsional Vibration Isolation Damper in Automotive Transmissions Based on In-situ Torque Measurement)

  • 김기우;장재덕
    • 한국소음진동공학회논문집
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    • 제22권4호
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    • pp.377-382
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    • 2012
  • This paper presents a proof-of-concept study on the evaluation of torsional vibration isolation performance through in-situ output torque measurement by using a non-contacting magneto-elastic torque transducer installed in the vehicle driveline system. The de-trending processing is first conducted to extract the torsional vibration from the measured driveline output torque. In order to estimate the transmissibility, primary performance indicator of a vibration isolator, the magnitude of transmitted torsional vibration with different frequencies is compared. From the conservative estimation results, the torsional damper built in a lock-up clutch of a torque converter is identified to be a vibration isolator. The evaluation results show that the fluid damping by torque converter outperforms the vibration isolation function of a torsional damper, and the isolation performance needs to be enhanced.

구동 출력 토크 측정을 이용한 비틀림 진동 절연 성능 평가 (Evaluation of Torsional Vibration Isolation Performance Using In-situ Driveline Output Torque Measurement)

  • 김기우;장재덕
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2012년도 춘계학술대회 논문집
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    • pp.382-387
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    • 2012
  • This paper presents a proof-of-concept study on the evaluation of torsional vibration isolation performance through in-situ output torque measurement by using a non-contacting magneto-elastic torque transducer installed in the vehicle driveline system. The de-trending processing is first conducted to extract the torsional vibration from the measured driveline output torque. In order to estimate the transmissibility, primary performance indicator of a vibration isolator, the magnitude of transmitted torsional vibration with different frequencies is compared. From the conservative estimation results, the torsional damper built in a lock-up clutch of a torque converter is identified to be a vibration isolator. The evaluation results show that the fluid damping by torque converter outperforms the vibration isolation function of a torsional damper, and the isolation performance needs to be enhanced.

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Critical Characteristics Estimation of a Large-Scale HTS Wind Turbine Generator Using a Performance Evaluation System

  • Kim, Taewon;Woo, Sang-Kyun;Kim, Changhyun
    • KEPCO Journal on Electric Power and Energy
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    • 제5권3호
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    • pp.229-233
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    • 2019
  • Large-scale High Temperature Superconducting (HTS) wind power generators suffer from high electromagnetic force and high torque due to their high current density and low rotational speed. Therefore, the torque and Lorentz force of HTS wind power generators should be carefully investigated. In this paper, we proposed a Performance Evaluation System (PES) to physically test the structural stability of HTS coils with high torque before fabricating the generator. The PES is composed of the part of a pole-pair of the HTS generator for estimating the characteristic of the HTS coil. The 10 MW HTS generator and PES were analyzed using a 3D finite element method software. The performance of the HTS coil was evaluated by comparing the magnetic field distributions, the output power, and torque values of the 10 MW HTS generator and the PES. The magnetic flux densities, output power, and torque values of the HTS coils in the PES were the same as a pole-pair of the 10 MW HTS generator. Therefore, the PES-based evaluation method proposed in this paper can be used to estimate the critical characteristics of the HTS generator under high magnetic field and high torque before manufacturing the HTS wind turbines. These results will be used effectively to research and manufacture large-scale HTS wind turbine generators.

중력의 영향에 따른 슬관절 굴곡근과 신전근의 등속성운동 평가 (Isokinetic Evaluation of Knee Flexors and Extensors on the Effect of Gravity)

  • 채윤원;정동훈;김진상
    • The Journal of Korean Physical Therapy
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    • 제10권1호
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    • pp.45-52
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    • 1998
  • Since isokinetic concise can give an evaluation of muscle strength with great accuracy and objectively, it is widely used as the one of the important methods for evaluation of muscle performance. The purpose of this investigation was to compare values uncorrected for gravity with values corrected for gravity and to determine the effect of making this correction on knee flexors and extensors at three speeds. This investigation measured values isokinetically at $60^{\circ}/sec,\;120^{\circ}/sec,\;and\;180^{\circ}/sec$ in 14 male and 17 fermale university students. The gravity effect torque(GET) is the torque resulting from the effect of gravity on the combined weight of the leg and dynamometer arm. The GET was added to the measured extensors peak torque and subtraced from the flexors peak torque to yield gravity corrected values. Failure to consider GET greatly underetimated extensors torque and overtestimated flexors torque. Physical therapists must remember the importance of making the gravity correction in patients with reduced torque output where the gravitational torque is a greater percentage of the measured torque to ascertain correctly the relative strength of antagonists inversely affected by gravity.

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원격전송장치를 이용한 비접촉식 회전 토크 측정장치의 정확도 평가 (Accuracy Evaluation of a Non-Contact Rotational Torque Measurement System by Using Telemeter)

  • 김갑순;주진원;권영하
    • 한국정밀공학회지
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    • 제11권1호
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    • pp.63-70
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    • 1994
  • This paper presents manufacturing and evaluation of a non-contact rotational torque measurement system which consists of torque cell, telemeter system, transmitter and receiver coil, transmitter, receiver and telemeter indicator. Static calibration test results show that the system has a maximum uncertaintry of 05% or less. A standar calibration system for rotational torque is used to evaluate the measurement system, As a result, the maximum uncertainty for measuring rotational torque by this system is 2% or less. We may conclude that the measurement system is sufficient to measure rotational torque of shaft in industry.

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Torque Ripple Reduction in Three-Level Inverter-Fed Permanent Magnet Synchronous Motor Drives by Duty-Cycle Direct Torque Control Using an Evaluation Table

  • Chen, Wei;Zhao, Ying-Ying;Zhou, Zhan-Qing;Yan, Yan;Xia, Chang-Liang
    • Journal of Power Electronics
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    • 제17권2호
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    • pp.368-379
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    • 2017
  • In this paper, a direct torque control algorithm with novel duty cycle-based modulation is proposed for permanent magnet synchronous motor drives fed by neutral-point clamped three-level inverters. Compared with the standard DTC, the proposed algorithm can suppress steady-state torque ripples as well as ensure neutral-point potential balance and smooth vector switching. A unified torque/flux evaluation table with multiple voltage vectors and precise control levels is established and used in this method. This table can be used to evaluate the effects of duty-cycle vectors on torque and flux directly, and the elements of the table are independent of the motor parameters. Consequently, a high number of appropriate voltage vectors and their corresponding duty cycles can be selected as candidate vectors to reduce torque ripples by looking up the table. Furthermore, small vectors are incorporated into the table to ensure the neutral-point potential balance with the numerous candidate vectors. The feasibility and effectiveness of the proposed algorithm are verified by both simulations and experiments.

Accuracy of different electronic torque drivers: A comparative evaluation

  • Ko, Byeong-Dae;Son, KeunBaDa;Kang, Seok Hyon;Lee, Kyu-Bok
    • The Journal of Advanced Prosthodontics
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    • 제11권6호
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    • pp.350-357
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    • 2019
  • PURPOSE. This study aims to evaluate the loosening torque on the implant fixture, and to assess the accuracy of difference electronic torque drivers. MATERIALS AND METHODS. Three electronic torque drivers were used to measure the loosening torque on the implant system (AnyOne; MegaGen). The implant fixtures were divided among the 3 electronic torque driver types (W&H, SAESHIN, and NSK group) and 9 for each group. The screws were fastened at the implant fixture by three electronic torque drivers using the tightening torques recommended by the manufacturers of the drivers. After 10 minutes, the screws were again fastened at the implant fixture with equal torque. Then, the loosening torques were measured with an MGT12 torque gauge (MARK-10, Inc.). This measurement procedure was repeated 10 times under loosening torques of 15 Ncm, 25 Ncm, and 35 Ncm. In the statistical analysis, all values of loosening torque were analyzed with the one-way ANOVA and Kruskal-Wallis test (α=.05) for comparative evaluation. RESULTS. There were significant inter-group differences at loosening torques of 15 Ncm and 25 Ncm (P<.05). The accuracy of the NSK driver was the highest, followed by SAESHIN and W&H. There was no significant difference between NSK and W&H at 35 Ncm (P>.05). The SAESHIN driver showed the closest loosening torque at 35 Ncm. CONCLUSION. The most accurate loosening torques were SAESHIN at 35 Ncm, and NSK at 15 Ncm and 25 Ncm. Since the loosening torque may vary depending on the tightening torques and electronic torque drivers, periodic calibration of the electronic torque driver is recommended.

자동차용 토크 컨버터의 수치해석적 연구(Part I) - 수력학적 설계와 순환유량의 평가 - (A Numerical Study on the Automotive Torque Converter(Part I) - Hydraulic Design and Evaluation of Circulation Flow Rate -)

  • 김홍식;박재인;주원구;조강래
    • 한국자동차공학회논문집
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    • 제6권5호
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    • pp.28-36
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    • 1998
  • In order to establish the hydraulic design process of the torque converter, pump, turbine and stator were designed by reverse design method including one dimensional analysis, angular momentum distribution and forced vortex design. And the significance of evaluation of the circulation flow rate in torus of the torque converter was verified by numerical calculation if the combined blade rows of pump and turbine. It was confirmed that the computational method using interrow mixing model by Park and Cho was reliable to predict the flow-field and performance of the torque converter.

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슬괵근의 길이 변화에 따른 근력 평가에 관한 연구 (A Study on the Evaluation of the Muscle Strength according to the Change of the Hamstring Muscle Length)

  • 최재청
    • The Journal of Korean Physical Therapy
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    • 제11권2호
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    • pp.1-4
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    • 1999
  • The purpose of this study was to analyze the changes of the muscle strength and length according to the changes of evaluation postures. Subjects of this study were 13 male and 13 female students. 6 evaluation postures were selected for this study(K90H90, K90H45, K90H0, K70H90, K70H45, K70H0 ; K90=knee $90^{\circ}$ flexion, K70=knee $70^{\circ}$ flexion, H90=hip $90^{\circ}$ fleion, H45=hip $45\circ}$ flexion. H0=hip $0^{\circ}$ ). The peak torque and hamstring muscle length(from fibula head to ischial tuberosity) were measured at each postures. The peak torque level was evaluated by make use of the KIN-COM. The results were as follows : 1. The peak torque in male was significantly increased with changes of hip flexion angle but not in female(($90^{\circ}\;>\;45^{\circ}\;>0^{\circ}$). 2. The hamstring length and peat torque in male and female was significantly changed according to the alteration of evaluation postures.

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