• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.5
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• pp.48-56
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• 2016

In this paper, we analyze the power flow of an eight-speed automatic transmission by using a lever analogy for the manufacturing of planetary gears. The results indicate that the engine power is passed down to the carrier and ring gear in the first double pinion planetary gear (DPPG1), and to the sun gear, carrier, and ring gear in DPPG3 for the first speed. Although the power flow is similar in the second speed, the power circulation occurs in the second single pinion planetary gear (SPPG2). For the third speed, the engine power is passed from the carrier to the ring gear in DPPG, at which point the power is split between the sun gears of SPPG2 and DPPG3.

• Tribology and Lubricants
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• v.39 no.5
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• pp.173-182
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• 2023

The composite planetary gear reducer, a power transmission component of armored vehicles, operates at a high torque and is used in severe environments such as mountain, gravel or unpaved roads. Therefore, they must be designed and manufactured to have high durability. To design such a planetary gear reducer, there are numerous specifications to validate, such as selecting the module and the number of teeth of each gear satisfied the requirements, and calculating gear specifications and durability strength. Because planetary gears constitute a combination of several gears, there are many restrictions and interferences in selecting the number of teeth and addendum modification coefficients, and designing the tooth shape. Developing an auto design program is necessary to design various planetary gears more conveniently and quickly. In this study, a planetary gear reducer design software, widely used in various machines and armored vehicles, was developed. This design software can automatically select the number of teeth and modules of the gears, calculate specifications and quickly evaluate its fatigue durability strength and scoring failure according to the planetary gear reducer design theory.

• Journal of the Korean Society of Industry Convergence
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• v.3 no.2
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• pp.107-114
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• 2000

Recently the studies on the vibration and the noise of a helical gear transmission have been focused on the many researchers. The manufacturing error and the deformation of the tooth profile, which generates the vibration and the noise of the gear transmission, are main factors. The major purpose of this study is to develop an optimal design program for reducing the vibration and the noise of the helical gear. To obtain the these results, we restrain the helical gear from the deformation of the tooth profile and increase the contact ratio within the optimal design program. Furthermore we made the three-dimensional solid modeling of the helical gear from the AutoCAD and the Pro/Engineer. This model will be available to generate the finite element model and the NC code.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.273-278
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• 2001

The transmission system of high speed train serve in the severe condition compared with those of other trains, namely, they have to transmit high power to run with high speed and they have to make maximum use of the limited space. To clarify the strength of gear for Korea High-speed train, a bending fatigue test is performed for the output gear of axle gear reduction unit. This paper reports the reviews of bending fatigue strength test method and the test results of output gear of axle gear reduction unit for high speed train.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.1-7
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• 2013

The present paper relates to a development of the Gear Detection Sensor for automotive manual transmission. To detect air gap from control finger to detecting zone of sensor based on non-contacted method, permanent magnet and linear type Hall IC are mounted in this sensor. Control finger is machined to 3 step heights to detect 3 gear stages such as In-Gear, Normal and Rear. After conducting actual experimentation based on exclusive Jig and FEM, it is described to consider possibility for automotive application of Gear Detection Sensor.

• Journal of KSNVE
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• v.5 no.2
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• pp.183-195
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• 1995

The mathematical model of the gear reductioner which consists which consists of the geared rotor-bearing system containing case is developed, assuming as the lumped parameter system. Constraints for vibration suppresion as well as strength of gear teeth, and shaft and kinematic conditions in gear pairs are considered. To find the design parameters satisfing the proposed constraints, a direct search method modified by the technique of Taguchi's experimental scheduling is used. One and two stepped gear reductioners are designed so that the criticl speeds due to the gear transmission error are moved out of the operating speed range.

• Journal of the Korean Society for Railway
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• v.4 no.2
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• pp.55-61
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• 2001

Since the plug type passenger door has two modes of motion, a power transmission unit must be capable of plug-in or plug-out mode, and sliding mode. Complex planetary gear train is proposed, which is composed of two 2K-H, I type planetary gear units. For the proposed complex planetary gear train, ranges of addendum modification coefficients which would not lead to interferences are analyzed, and optimal addendum modification coefficients among these ranges which generate the maximum efficiency are presented. Based on the results of analysis on interferences, efficiencies and torque ratios, the specifications for the complex planetary gear train were determined. It has been shown by tests of the complex planetary gear train manufactured that the gear train worked well with good agreements of analysis.

• Journal of Mechanical Science and Technology
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• v.20 no.5
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• pp.583-590
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• 2006

It is hard to inspect the state of lubrication of an automobile transmission visually. Thus, it is necessary to develop a new inspection method. Wear debris can be collected from the lubricants of an operating transmission of an automobile, and its morphology will be directly related to the friction condition of the interacting materials from which the wear debris originated in the lubricated transmission. In this study, wear debris in lubricating oil are extracted by membrane filter $(0.45{\mu}m)$, and the quantitative values of shape parameters of wear debris are calculated by digital image processing. These shape parameters are studied and identified by an artificial neural network algorithm. The results of the study may be applicable to the prediction and diagnosis of the operating condition of transmission gear.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.97-98
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• 2006

This study deals with the Transmission Error of gear tooth profile by modifying a Profile and lead of a surface of Tooth. First, we experimentally confirmed that the Transmission Error is a synthesis of the sliding Velocity between both gears. Since various types of Transmission errors appear in the experiments, we introduced definition of Transmission Error and The Optimism Design by modifying a surface parameters The test stand's performance is then evaluated through a series of multiple torque transmission error tests. Comparisons are made between data recorded before and after the test stand's redesign, and subsequently repeatability studies are performed to verify the veracity of the measured data. Finally, the experimental results are compared to the analytical predictions of two different gear analysis programs.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.10
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• pp.36-45
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• 1996

The precise estimation of the reliability and life of the Ravigneaux planetary gear train used in an automatic transmission is necessary in order to enable accurate material and geometric properties to reliability distrobution and the number of load cycles at failure. These are critical for the proba- bilistic design of complex planetary gear system as Ravigneaux type particularly during various gear ratios. The Ravigneaux planetary gear train has five gears, such as a forward and a reverse sun gear, a short and a long pinion, and an annulus gear. In this paper, the Ravigneaux gear system is analyzed to figure out the reliablity distribution. i.e. the probability of survival in the system without its overhaul. First, the reliablity method based on the Weibull distribution is used in conjuction with the Palmgren's model to predict both the individual reliabilities of its components and the nimber of load cycles when the system failed. Then using the presented method, the life of the Ravigneaux gear system can be determined. Alwo the different design parameters such as tooth face width, material property, and Weibull exponent are applied and reached to optimal ones. Thus, the precise evaluation of the reliability and life of the Ravigneaux planetary gear train used in an automatic transmission can be effectively carried out.