• Journal of Advanced Marine Engineering and Technology
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• v.32 no.8
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• pp.1149-1156
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• 2008

The principle of self clamping friction clutch is presented in this paper and the transmitted torque capacity is also calculated. In order to enlarge the friction force, a part of rotating force of driving side is converted to normal force of friction materials by clamping arm. The increased normal force of friction materials assures the large friction force and the transmitted torque capacity of clutch becomes large. The self clamping friction clutch is adopted in the tube type air pressure clutch and the condition of stability is investigated. It is proven that the inclined angle of clamping arm and the friction factor of friction materials are the essential elements in stability and torque capacity of self clamping friction clutch. The transmitted torque capacity of self clamping friction clutch is compared with air pressure clutch. The normal force of friction lining is magnified by 1/(1-k) and the transmitted torque capacity is also magnified with same proportion comparing with air pressure clutch. The larger the friction factor of friction lining, the larger the magnification factor. The longer the clamping arm, the smaller the magnification factor. It must be also noted that the value of k=${\mu}Y/X$ is the criterion of stability. If the value of k=${\mu}Y/X$ is greater than or equal to 1, the self clamping friction clutch is unstable and it can not be used as clutch.

• 유체기계공업학회:학술대회논문집
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• 1998.02a
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• pp.3-10
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• 1998

The situation frequently occurs in which the input torque capacity of the converter should be changed. It is known that the modification of the ou angles of the torque converter elements is suitable for such situation with diameter of flow path of the converter maintained. But so far it has been, predict correctly the converter characteristics as well as the effects of oulet torque capacity in the past numerical methods. In the present numeric introducing the interrow mixing planes, the torque capacity was satifactorily and it was shown that the torque capacity could be effectively changed by the oulet blade angles of pump and stator.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.705-710
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• 2004

In the present study, a transient incompressible viscous turbulent flow is simulated for the automotive torque converter with moving mesh technique. For the analysis, entire torque converter flow passages are modeled. Computed torque ratio, capacity factor and efficiency show a good agreement with the experiment data. The flow instabilities characterized by back-flow and wake etc. appeared in some cascade passages are shown to be Propagating along tangential direction. These flow patterns are mainly influenced by the pump and turbine blade passing and can't be predicted through conventional steady simulation with a mixing plane approach. The understanding of the unsteady flow characteristics in a torque converter achieved in the present study may lead to the optimal design of a torque converter.

• The KSFM Journal of Fluid Machinery
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• v.9 no.5 s.38
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• pp.36-41
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• 2006

In the present study, a transient incompressible viscous turbulent flow is simulated for the automotive torque converter with moving mesh technique. For the analysis, entire torque converter flow passages are modeled. Computed torque ratio, capacity factor and efficiency show a good agreement with the experiment data. The flow instabilities characterized by back-flow and wake etc. appeared in some cascade passages are shown to be propagating along tangential direction. These flow patterns are mainly influenced by the pump and turbine blade passing and can't be predicted through conventional steady simulation with a mixing plane approach. The understanding of the unsteady flow characteristics in a torque converter achieved in the present study may lead to the optimal design of a torque converter.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.690-695
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• 2004

The present study is an investigation on the characteristics of heavy load toque converter by experimental process. To get the dynamic performance, the dynamometer was used with a parameters of speed, torque, oil pressure and oil flux, etc. The torque converter was tested for various input speed, output oil pressure and input oil flow rate. All experiments were investigated in case that the speed ratio is increased. The torque ratio and capacity factor was in inverse proportion to speed. Engine revolution had a more effects at region of low speed ratio. But, the opposite phenomena were represented increase of efficiency. In result of this experiments, the characteristics of torque converter were not influenced by oil pressure and oil flux.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.1
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• pp.244-254
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• 2002

To enhance the acceleration performance and fuel consumption rate of a vehicle, the torque converter is modified or newly-developed with reliable analysis model. Up to recently, the one dimensional performance model has been used for the analysis and design of torque converter. The model is described with constant parameters based on the concept of mean flow path. When it is used in practice, some experiential correction factors are needed to minimize tole estimated error. These factors have poor physical meaning and cannot be applied confidently to the other specification of torque converter. In this study, the detail dynamic model of torque converter is presented to establish the physical meaning of correction factors. To verify the validity of model, performance test was carried out with various input speed and oil temperature. The effect of oil temperature on the performance is analysed, and it is applied to the dynamic model. And, to obtain the internal flow pattern of torque converter, CFD(Computational Fluid Dyanmics) analysis is carried out on three-dimensional turbulent flow. Correction factors are determined from the internal flow pattern, and their variation is presented with the speed ratio of torque converter. Finally, the sensitivity of correction factors to the speed ratio is studied for the case of changing capacity factor with maintaining torque ratio.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.2
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• pp.203-210
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• 2003

A simulation study was carried to analyze the vehicle fuel consumption on component basis. Experiments was also carried out to identify the simulation results, under FTP-75 Hot Phase driving conditions. and arbitrary driving conditions. A good quantitative agreement was obtained. Based on the simulation, fuel energy was used in pumping loss(3.7%), electric power generation(0.7%), engine friction(12.7%), engine inertia(0.7%), torque converter loss(4.6%), drivetrain friction(0.6%), road-load(9.2%), and vehicle inertia(13.4%) under FTP-75 Hot Phase driving conditions. Using simulation program, the effects of capacity factor and idle speed on fuel consumption were estimated. A increment of capacity factor of torque converter resulted in fuel consumption improvement under FTP-75 Hot Phase driving conditions. Effect of a decrement of idle speed on fuel consumption was negligible under the identical driving conditions.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.558-564
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• 2001

General vehicle is evaluated by its acceleration, fuel economy, NVH (Noise, Vibration and Harshness) and subjective (Launching feel) performance. The first step to enhance its performance is to know how much each component affects on the vehicle performance. It is very important to know what is the key factor of the component among many specifications. Hydraulic torque converter can be expressed by means of its performance curve (torque ratio and capacity factor). In this paper, the key factor of torque converter, which affect vehicle performance, are explored by using Taguchi method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.6
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• pp.1085-1091
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• 2002

General vehicle is evaluated by its acceleration, fuel economy, NVH (Noise, Vibration and Harshness) and subjective (such as launching feel) performance. The first step to enhance its performance is to know how much each component affects on the vehicle performance. It is very important to know what is the key factor of the component among many specifications. Hydraulic torque converter can be expressed by means of its performance curve (torque ratio and capacity factor). In this paper, the key factor of torque converter, which affect vehicle performance, are explored by using Taguchi method. Moreover, general sensitivity analysis method is compared with Taguchi's experiment.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.57-61
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• 2006

In the single-phase switched reluctance motor (SRM) drive, the required DC source is generally supplied by the circuit consisting of bridge rectifier and large filter capacitor connected with DC line terminal. Due to the large capacity of the capacitor, the charged time of capacitor is very short from the AC source. Lead to the bridge rectifiers draws pulsating current from the AC source side, which results in reduction of power factor and low system efficiency. Therefore a novel single-phase SRM drive system is presented in this paper, which includes drive circuit realizing reduction of torque ripple and improvement of power factor with a novel switching topology. The proposed drive circuit consists of one switching part and diode, which can separate the output of AC/DC rectifier from the large capacitor and supply power to SRM alternately, in order to realize the torque ripple reduction and power factor improvement through the switching scheme. In addition, the validity of the proposed method is tested by some simulations and experiments.