Determination of safety factor for agricultural gear reducer using simulation software

홍순중,김용주,정선옥,최창현,박수복,노현석,장정훈 충남대학교 농업과학연구소 2018 Korean Journal of Agricultural Science Vol.45 No.2

Agricultural gear reducers are used in a variety of agricultural machinery designs such as in agricultural tractors and transport cars, and even greenhouses. For greenhouses, a gear reducer is used to control windows on the side and the roof. Gear reducers for agricultural applications are designed using the empirical method because of the lack of a standard for experimentation. Simulation is necessary for the optimal design of an agricultural gear reducer. There are many advantages to this optimization such as low-cost maintenance, reduced size, and weight. In this study, bending and contact safety factor simulation for the gear reducer of a greenhouse was conducted by decreasing the face widths of helical gear shaft 2 and shaft 3 from 30.8 and 30 mm, respectively, at an interval of 4 mm. The bending and contact safety factors were calculated using AGMA standard. Simulation results showed that bending and contact safety factors decreased rapidly when the face width of the helical gear on shaft 2 was 30 mm and the face width of helical gear on shaft 3 decreased from 30.8 mm to 26.8 mm, suggesting that it would be safe to reduce the face width of the helical gear on shaft 3 to 26.8 mm. The reduction of the face width also reduced the weight of the agricultural gear. This study suggests that the agricultural gear reducer safety factor decreases as the face width decreases.

The Stress Analysis of Planetary Gear System of Mixer Reducer for Concrete Mixer Truck

Myung Ho Bae,Tae Yeol Bae,Yon Sang Cho,Ho Yeon Son,Dang Ju Kim 유공압건설기계학회 2015 드라이브·컨트롤 Vol.12 No.4

In general, the gears of mixer reducer for concrete mixer truck make use of the differential type planetary gear system to rotate mixer drum smoothly on the initial conditions. The planetary gear system is very important part of mixer reducer for concrete mixer truck because of strength problem. In the present study, calculating the gear specifications and analyzing the gear bending & compressive stresses of the differential planetary gear system for mixer reducer are necessary to analyze gear bending and compressive stresses confidently, for optimal design of the planetary gear system in respect to cost and reliability. As a result, analyzing actual gear bending and compressive stresses of the planetary gear system using Lewes & Hertz equation and verifying the calculated specifications of the planetary gear system, evaluate the results with the data of allowable bending and compressive stress from the Stress-No. of cycles curves of gears.

The Stress Analysis of Planetary Gear System of Mixer Reducer for Concrete Mixer Truck

Bae, Myung Ho,Bae, Tae Yeol,Cho, Yon Sang,Son, Ho Yeon,Kim, Dang Ju The Korean Society for Fluid Power and Constructio 2015 드라이브·컨트롤 Vol.12 No.4

In general, the gears of mixer reducer for concrete mixer truck make use of the differential type planetary gear system to rotate mixer drum smoothly on the initial conditions. The planetary gear system is very important part of mixer reducer for concrete mixer truck because of strength problem. In the present study, calculating the gear specifications and analyzing the gear bending & compressive stresses of the differential planetary gear system for mixer reducer are necessary to analyze gear bending and compressive stresses confidently, for optimal design of the planetary gear system in respect to cost and reliability. As a result, analyzing actual gear bending and compressive stresses of the planetary gear system using Lewes & Hertz equation and verifying the calculated specifications of the planetary gear system, evaluate the results with the data of allowable bending and compressive stress from the Stress-No. of cycles curves of gears.

The Stress Analysis of Planetary Gear System of Mixer Reducer for Concrete Mixer Truck

배명호,배태열,조연상,손호연,김당주 사단법인 유공압건설기계학회 2015 드라이브·컨트롤 Vol.12 No.4

In general, the gears of mixer reducer for concrete mixer truck make use of the differential type planetary gear system to rotate mixer drum smoothly on the initial conditions. The planetary gear system is very important part of mixer reducer for concrete mixer truck because of strength problem. In the present study, calculating the gear specifications and analyzing the gear bending & compressive stresses of the differential planetary gear system for mixer reducer are necessary to analyze gear bending and compressive stresses confidently, for optimal design of the planetary gear system in respect to cost and reliability. As a result, analyzing actual gear bending and compressive stresses of the planetary gear system using Lewes & Hertz equation and verifying the calculated specifications of the planetary gear system, evaluate the results with the data of allowable bending and compressive stress from the Stress-No. of cycles curves of gears.

The Stress Analysis of Planetary Gear System of Mixer Reducer for Concrete Mixer Truck

Myung Ho Bae,Tae Yeol Bae,Yon Sang Cho,Ho Yeon Son,Dang Ju Kim 유공압건설기계학회 2015 유공압건설기계학회 학술대회논문집 Vol.2015 No.10

In general, the gears of mixer reducer for concrete mixer truck make use of the differential type planetary gear system to rotate mixer drum smoothly on the initial conditions. The planetary gear system is very important part of mixer reducer for concrete mixer truck because of strength problem. We calculate the gear specifications and analyze the gear bending & compressive stresses of the differential planetary gear system of mixer reducer. It is necessary to analyze gear bending and compressive stresses confidently for optimal design of the planetary gear system in respect of cost and reliability. Thus, we analyze actual gear bending and compressive stresses of the planetary gear system using Lewes & Hertz equation and verify the calculated specifications of the planetary gear system by evaluating the results with the data of allowable bending and compressive stress from the Stress-No. of cycles curves of gears.

Influence of Housing Stiffness of the Slewing Reducer of a Tower Crane on the Load Distribution Pattern over the Gear Tooth Flank

박영준,조성재,정우진,오주선,이상대,신인경,김정길 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.12

To increase the life of slewing reducers, the reliability of their gearboxes is essential. They should be designed, simulated, and tested considering the installation environment and actual load conditions. Many studies have been conducted on the reliability improvement of gearboxes for reducers; however, a few studies have considered actual input load conditions. Furthermore, there is insufficient research on the effects of housing stiffness on gear misalignment, gear life, and load distribution and maximum contact load of the gear tooth flank. In this study, the effects of housing stiffness were analyzed using input torque measurements to investigate the causes of ring gear damage during durability tests on a slewing reducer. The contact pattern of the gear tooth flank was analyzed by applying dyes to all gears inside the reducer, and the results were compared with simulation results. A large edge contact in the first-stage ring gear of conventional slewing reducers was suggested as the cause of the ring gear damage. A new simulation model using a gearbox housing with an increased stiffness showed that edge contact was improved by the decreased gear misalignment. No abnormal wear and/or partial fracture of the ring gear occurred during the durability test on the improved model under the same conditions as those of the initial model. These results indicate that an increase in the stiffness of the housing reduced the gear misalignment, improved the load distribution, decreased the maximum load of the tooth flank, and increased the gear life.

Study on Tooth Micro-geometry Optimization of Rear Gear Set in 2 Speed Planetary Gear Reducer

Min-Hyung Jeon(전민형),Lae-Sung Kim(김래성),Seung-Yoon Noh(노승윤),Qin Zhen(진진),Chang Choi(최창),Sung-Ki Lyu(류성기) 한국기계가공학회 2017 한국기계가공학회지 Vol.16 No.5

Gear tooth micro-geometry modifications include the intentional removal of material from the gear teeth flanks, so that the shape is no longer a perfect involute. If the gear shapes are perfect, then the gear tooth meshing is better, therefore the gears will transmit input torque in a more efficient manner without the generation of high frequency engine fluctuation noise. In this paper, we study tooth micro-geometry optimization of rear gear set in 2 speed planetary gear reducers. Analysis revealed problems which are need of modification. Based on the results, tooth micro-geometry was used to deal with load distributions on the rear gear set.

복합가공기를 사용한 정밀유성기어장치 개발에 관한 연구

손미곤,황종대,정윤교 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

First of all precise reduction ratio and gear tooth profile should be designed for device of planetary geared reducer design. but the technology in the domestic industry is limited from middle to big scale and low reduction device of planetary geared reducer. Consequently establishing the technology for the compact and high reduction device of planetary geared reducer is needed. This study deals with the high reduction and compact device of planetary geared reducer. We implemented the precise design work using PGT Designer. We performed the Mill-Turn composite simultaneous processing for improved concentricity and surface roughness but not existing method of gear cutting comprises turning and hobbing. As a result, we will develop the super-precision and high reduction, high efficiency device of planetary geared reducer.

콘크리트 믹서 트럭용 믹서 감속기의 차동 유성 기어 트레인에 대한 위험속도 해석

배명호(Myung Ho Bae),배태열(Tae Yeol Bae),김당주(Dang Ju Kim) 유공압건설기계학회 2017 드라이브·컨트롤 Vol.14 No.1

The power train of a concrete truck mixer reducer includes differential planetary gears to get a large reduction ratio for operating the mixer drum in a compact structure. These differential planetary gears are a very important part of the mixer reducer where strength problems are the main concern. Gear bending stress, gear compressive stress and scoring failure are the main concerns. Many failures in differential planetary gears are due to the insufficient gear strength and resonance problems caused by major excitation forces such as gear mating failure in the transmission. In the present study, where the excitation frequencies are the gear tooth passing frequencies of the mating gears, a Campbell diagram is used to calculate differential planetary gear critical speeds. Mode shapes and natural frequencies of the differential planetary gears are calculated by CATIA V5. These are used to predict gear resonance failures by comparing the working speed range with the critical speeds due to the gear transmission errors of the differential planetary gears.

1.7톤급 소형 굴착기용 주행 감속기의 복합 유성기어류에대한 강도 평가

남석주,배명호,조연상 한국트라이볼로지학회 2022 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.38 No.1

A 1.7-ton grade small excavator is a construction equipment that can perform various functions in limited spaces where heavy equipment cannot enter easily. Owing to the recent acceleration of urbanization, it has been used increasingly in drainage and gas pipes, as well as for road repair works in urban areas. The power train of a traveling reducer for a 1.7-ton grade small excavator utilizes a complex planetary gear system. Complex planetary gears are vital to the power train of a traveling reducer as it mitigates the fatigue strength problem. In the present study, the specifications of a complex planetary gear train are calculated; furthermore, the gear bending and compressive stresses of the complex planetary gears are analyzed to achieve an optimal design of the latter in terms of cost and reliability. In this study, the actual gear bending and compressive stresses of a planetary gear system are analyzed using a self-developed gear design program based on the Lewes and Hertz equation. Subsequently, the calculated specifications of the complex planetary gears are verified by evaluating the results with the data of allowable bending and compressive stress based on curves of stress vs. number of cycles of the gears.