• 한국기계가공학회지
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• 제16권3호
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• pp.113-118
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• 2017

In this paper, a study on the performance evaluation of a cycloid reducer for remote weapons systems is presented. Reduction gears applied to remote weapons vehicles need to be compact and capable of large torque transmissions as well as require structural optimization, high load capacity, and high precision position control. To meet these requirements, a cycloid reducer with low backlash, high precision, high overload capability, high rigidity, and high efficiency is required. Thus, a cycloid reducer with a reduction ratio of 127:1, backlash of 1 arcmin (1/60 deg) or less, and reduction gear efficiency of 70% or more, which are the design requirements for a remote weapons system, was designed utilizing a design and analysis program (HEXAGON) for gear engineering. To confirm the performance of the cycloid reducer, the hardness of the main components of the manufactured cycloid reducer, reduction ratio, and efficiency were measured.

• Tribology and Lubricants
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• 제35권1호
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• pp.71-76
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• 2019

The differential planetary gear reducer as a main component of the concrete mixer driving mechanism requires a strong torque to mix concrete compounds. As this component is currently dependent on imports, it is necessary to develop it by conducting a study on vibration analysis and the resonance problem. The noise and vibration of a concrete mixer reducer increase owing to the transmission error of planetary gears, and the damage of components occurs owing to the problems in design and production. In this study, the tooth-passing frequency is calculated to evaluate the noise and vibration of a mixer reducer, and a fast Fourier transform (FFT) analysis is conducted through a vibration test using an acceleration sensor. The vibration of the reducer is measured at three points of input and output of the shaft and planetary gear housing with fixed and variable revolutions per minute. The operating conditions of gears and bearings are evaluated by performing the FFT analysis, and the resonance problem is verified. The results show that No. 1 pinion and ring gears revolve disproportionately. The amplitude values appear high, and the wear of tooth faces occur in tooth-passing frequencies and harmonic components of No. 1 and No. 2 pinion-ring gears. Therefore, we conclude that design changes in the reducer and a correction of tooth profiles are required.

• 한국기계가공학회지
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• 제3권2호
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• pp.46-52
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• 2004

The most of reducers consist of many gear parts, but a ball reducer never contains a gear. As the ball reducer with gearless has no back lash, it is necessary more and more to precision machine. The reducing of ball reducer happens by cycloid curves and all instant relative velocity centers always pass on a given constant position when rotational running. Then, it is difficult to calculate cycloid curve for design and machining. So, this paper studied a software for the design of the ball reducer design and machined all parts included among cycloid curve. By using the developed software, this study has large benefit to design every ball reducer.

• 농업과학연구
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• 제43권4호
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• pp.656-664
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• 2016

Gear reducers are widely used for various agricultural machinery applications such as greenhouses, tractors, and agricultural vehicles. However, thermal deformation and surface pitting at gear tooth flank frequently occur in gear reducers due to high torque. Thus, surface heat treatment of gears is required to improve wear and fatigue resistance. The objective of this study was to simulate the load capacity of the agricultural gear reducer. The simulation was performed for the following three surface heat treatment methods: untreated gears, nitriding heat treatment, and induction hardening method, those mostly used for agricultural gear reducers. The load capacity of the gear reducer was simulated using the safety factor, limit bending stress, and limit contact stress of the gear. The simulation of the load capacity was conducted using KISSsoft commercial software for gear analysis. The main results of simulation test were as follows: first, the nitriding heat treatment resulted in the highest safety factor for bending stress, which was increased about 77% from those of the untreated gears. Second, the induction hardening was the highest safety factor for contact stress, which was increased about 150% from those of the untreated gears. The safety factor for contact stress of the induction hardening was increased about 64% from those of the nitriding heat treatment. The study result suggested that the surface heat treatments could enhance load capacity and that the method of surface heat treatment should be determined based on simulation results for appropriate use scenarios.

• Journal of Advanced Marine Engineering and Technology
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• 제39권9호
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• pp.895-902
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• 2015

본 연구에서는 사이클로이드기어시스템 1단, 한 쌍의 평기어시스템, 입력 축, 출력 축, 하우징으로 구성되어 있는 2MW급 풍력발전기용 사이클로이드 피치감속기에 대해 유한요소해석을 통한 안정성평가를 수행하였다. 또한 평기어에 대해서는 ISO 6336에 의한 기어강도해석을 통하여 안정성 여부를 평가하였다. 2MW급 풍력발전기용 사이클로이드 감속기의 고유진동 특성 해석을 수행하였고, 입력축 질량불평형, 출력축 질량불평형, 평기어 치합전달오차, 사이클로이드기어 치합전달오차 등에 발생하는 가진원에 대해 위험속도 분석을 하였다.

• 드라이브 ㆍ 컨트롤
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• 제19권4호
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• pp.1-9
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• 2022

The structure and operating principle of the 2-speed shift reducer were explained, the allowable bending stress value of the material was compared with the analysis result through FM structural analysis program, and the average stress distribution value of von Mises was performed on the gear root atmosphere. The structural safety of the 2-speed planetary gear reducer was verified through FM structural analysis. The natural frequency was calculated by applying the specifications of the planetary gears of the 2-speed gearbox, and the critical speed of resonance was calculated by calculating the natural frequency and the transmission error of the engaged gear pair. As a result of analyzing the critical speed, since it is formed higher than the actual operating speed range, it is considered safe because there is no resonance problem due to the suggested specifications of the planetary gears of the 2-speed shift reduction.

• 동력기계공학회지
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• 제20권1호
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• pp.57-62
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• 2016

In this study, design the core part of the driving of the robot. The power of the driving is window motor for automobiles obtained by using a method of directly to the motor shaft of the worm gear type. The decelerator consists of a worm gear to receive power from the motor shaft, Helical gear contact to worm gear, a pinion gear to be connected in line with the helical gear, and an output shaft to be engaged to the pinion gear. Drive system by using the power from the motor shaft based on the deceleration gear designed by the gear ratio set by the gear teeth increases the torque.

• 한국생산제조학회지
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• 제22권1호
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• pp.29-35
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• 2013

The pitch reducer consists of several planetary gearsets, and they should have good load distribution over gear tooth flank and load sharing among the planets to improve the durability. This work investigates how bearing internal clearances influence both the load distribution over the gear tooth flank and the planet load sharing. A whole system model is developed to analyze a pitch reducer. The model includes non-linear mesh stiffness of gears, non-linear stiffness of bearings. The results indicate that the face load factor and mesh load factor decrease, and the fatigue life of output shaft bearings increase as bearing internal clearances of output shaft decrease. Therefore, the internal clearance of output shaft bearing must be considered when designing the pitch reducer for wind turbines.

• 한국기계가공학회지
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• 제18권12호
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• pp.15-21
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• 2019

The worm reducer is capable of quadrature power transmission when the shafts are disposed at right angles to each other. Since a large reduction ratio can be obtained of up to approximately 1/100 and a sliding movement is performed during operation compared with other gears, the noise and vibration are small, and there is the advantage that reverse rotation can be prevented. On the other hand, severe wear and damage are displayed on the gear and worm tooth surface, and many defects, such as intense heat generation of the reducer, occur. In the reducer case, the four-piece casing method was selected to solve the problems of heat generation, transmission efficiency, and assemblability. In this paper, we analyzed the problems of the worm and worm wheel (the core parts of a 5-Ton worm reducer) and casing through these methods and researched how to solve them.

• 대한기계학회논문집A
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• 제34권7호
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• pp.935-941
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• 2010

하나로는 한국에 설치되어 있는 열출력 30MW의 개방 수조형 연구로 이다. 이는 발전로와 달리 원자로에서 발생하는 열을 이용하여 전기를 생산하는 것 대신에 원자로의 노심 온도를 유지하기 위하여 냉각탑을 통해 대기로 이 열을 냉각한다. 냉각탑 월간 점검 중에 냉각탑 4번의 냉각팬 감속기가 기준을 상회하는 고진동을 기록하였다. 본 연구의 목적은 고진동의 원인을 찾아 정상적으로 수리하기 위함이다. 연구 방법은 FFT 스펙트럼 기법을 적용하여 고진동의 원인을 분석하였다. 그 결과 고진동 주파수는 피니언 기어의 고유 진동수의 두 배인 354Hz이었다. 피니언 기어를 점검한 결과 이빨 표면이 깨져 있었다. 깨진 피니언 기어를 제거하고 새것으로 교체한 후에는 감속기는 정상적으로 작동하였다.