• 한국안전학회지
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• 제21권3호
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• pp.1-7
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• 2006

Nowadays, out of other transmission parts, the sleeve is getting more and more important part for exact and smooth shifting from gear ratio change whenever drivers are needed. To exact and smooth shifting when drivers are needed, all the parts connected with gear shifting should be machined exactly and having dimensions designers are intended. Especially, in case of the sleeve that the most important functional part to shift from gear ratio change that drivers are intended, it needs high precision grade and quality in both sides runout and outer dia runout as well as inner spline small dia & large dia. Because it's assembled with the synchro hub spline and shifted directly with the mating cone. So, it should be applied the hear treatment(hereinafter referred to H.T.M.T) to prevent the friction and percussion loss from shifting with mating cone. At this time, the deformation problems are raised from almost H.T.M.T. process and it makes the inferior part.

• 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.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.731-736
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• 2011

In this study, the safety of the driving gear reducer of ESW traveling sea water screen was evaluated through seismic analysis. Mode analysis of gear reducer was performed for reliability of analysis. Seismic analysis was performed in Operating Basis Earthquake(OBE) and Safe Shutdown Earthquake(SSE), which was applied as design condition using Floor Respnse Spectrum(FRS). The maxsimum displacement of gear reducer under OBE and SSE were 0.0137 mm and 0.0241 mm, respectively. The maximum stress of gear reducer under OBE and SSE were 2.42 MPa and 4.36 MPa, respectively.

• 한국정밀공학회지
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• 제17권1호
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• pp.61-67
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• 2000

Gears are the most commonly used parts in automotive and industrial applications. One of most common modes of gear failures is tooth breakage, which is usually produced by the bending fatigue failure. It is important to manufacture the gears which can withstand the applied stresses in view of safety and economic requirement. This paper deals with bending fatigue strength for cold forged bevel gear. Especially, to compare fatigue characteristics for manufacturing processes difference, bending fatigue tests of bevel gears made by three different processes respectively. Results indicate that the fatigue strength of bevel gear is improved by cold forging process. Intergranular fracture is found on fatigue fracture surface, and dimples are observed on final fracture surface. The fatigue failure cannot be considered as a deterministic quantity, but must be characterized statistically. This study proposes a method to estimate bending fatigue lift of the bevel gear using the probability-load-life and Weibull analysis.

• 한국생활과학회지
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• 제12권4호
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• pp.571-578
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• 2003

The purpose of this research was to provide basic information for enhancing sizing suitability in terms of the need for appropriate fit in head gear. The method for this research was to survey about sizing system of head gear, basic measure part, repair service. The subject of this study were 15 head gear companies. The results of this research were as follows : 1. In the sex target analysis according to company type, most of fashion brand companies were producing woman's head gear. In case of the company to produce man's head gear, sizes appeared variously. On the other hand, the sports brand companies were producing unisex head gear and safety helmet companies were producing man's one. 2. The number of size of head gear manufacturing companies were under 3 sizing system. This means that the sizing system of current head gear manufacturing company isn't various. 3. While the measuring part using currently in the company was head girth, one to be considered necessary for manufacturing of head gear except the head girth was head height.

• 한국기계가공학회지
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• 제18권12호
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• pp.7-14
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• 2019

A marine turning gear controls the position of the piston-crank mechanism by rotating the flywheel of the marine engine at a low speed, which is the main auxiliary machine that enables the disassembly and maintenance of the engine. In this study, the safety factor for surface durability and tooth bending strength was improved by the design modification of the marine turning gear based on the spur planetary gear. Angular velocity, torque, and efficiency of the turning gear were measured using a reliability evaluation tester, and a multibody dynamics model for analysis corresponding to the test results was developed. Finally, it was confirmed that the design improvements improved the tooth surface damage of the sun gear in the 3^rd reduction stage.

• 수산해양기술연구
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• 제59권4호
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• pp.377-386
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• 2023

As discarded fishing gear settles or floats on the seabed, it destroys the spawning and habitat of fisheries resources that causes various safety accidents and adverse effects on the environment, such as generating microplastics and causing ship accidents. In order to solve this problem, this study is intended to present an implementation plan for establishing a fishing gear deposit system in order to use it as basic data for establishing policies for fishing gear management in Korea. In order to successfully implement the fishing gear deposit system, the deposit system must be established in the form of fishing gear completed at the production stage. It was found that the marking of the object should be easy, and that determining an appropriate deposit amount to motivate the return of waste fishing gear and establishing a convenient return procedure for returned waste fishing gear were important factors. In addition, transparent management of unreturned deposits and mandatory use of fishing gear subject to the deposit system for fishermen will be necessary. The role of a specialized organization to manage and operate all of these procedures is also very important. It is necessary to establish a new mandatory provision in the Fisheries Act to require fishermen who directly use fishing gear to use fishing gear with a deposit refund mark, and to ensure the implementation of the deposit system by linking it with the evaluation items of government policy projects. Since the main purpose of the deposit system is to collect discarded fishing gear, a support plan will be necessary in accordance with the purchase project for fishing waste salvaged by local governments in 2020.

• 한국기계가공학회지
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• 제20권12호
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• pp.44-53
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• 2021

As environmental issues have emerged worldwide, emission gas regulations have been strengthened. In the construction machinery sector, studies have been actively conducted to utilize the power source of electric motors owing to the increasing demand for zero emissions. In this study, the gear specifications of an electric axle for construction machinery were selected by considering the specifications of the motor, gear tooth contact pattern, and face load factor. The gear strength evaluation was performed at the system level using the simulation model. The bending and contact strength of the spiral bevel gears and the bending strength of the planetary gear set showed a safety factor of 1 or more. However, the contact strength of the planetary gear set showed a safety factor of 0.92. Conservative results were derived by performing the analysis under the rated load condition of the motor. However, the ratio of the equivalent torque to the rated torque of the motor was 45% or less, hence, it was determined that no difficulties should arise regarding the durability of the axle.

• 한국안전학회지
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• 제9권3호
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• pp.28-33
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• 1994

It is very important to have exact informations on the properties and characteristics of the sintering material as a new material of machine elements. To study the sintering spur gear and the sintering specimen to be consisted of Fe-Cu-C, the constant stress amplitude fatigue test is performed by using an electrohydrolic survo-controlled pulsating tester. Consequently, the S-N curves are obtained and the fatigue strength is compared with flaw depth. Accordingly, this study presents the fatigue strength of sintering spur gears, the critical notch depth of sintering materials and the effects of flaw depth on the bending fatigue strength.

• 한국의류학회지
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• 제36권1호
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• pp.46-55
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• 2012

Foot and Mouth Disease (FMD) is highly contagious and highly lethal to cloven-hoofed animals. In the winter of 2010, an outbreak of FMD in Korea caused a great deal of economic damage as well as serious mental and physical damage to people who participated in preventive activities. This study provides preliminary data for designing safe and functional protective clothing and gear for individuals who participate in FMD preventive activities. This study was accomplished with multilateral methods such as a documentary survey, field trips, sample analysis of protective clothing and gear, questionnaire studies and focus interviews. As a result, we found that most workers wore low-priced protective clothing that was low in safety functions and rarely wore extra protective gear. Also pointed out was dissatisfaction with: protective clothing and gear, problems related to damage, discomfort, contamination, problems in protective gear related to waterproof functions, protection against harmful substances, discomfort, coldness, and damage. Safe protective clothing could be developed that protects the actual wearers if these results are reflected in the improvement of protective clothing and gear.