• Proceedings of the KSME Conference
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• 2001.11a
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• pp.623-628
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• 2001

The styling of passenger car wheels and their effect on vehicle appearance has increased in importance in recent years. The wheel designer has been given the task of insuring that a wheel design meets its engineering objectives without affecting the styling theme. The wheel and tire system is considered as a vehicle component whose dynamic modal information of the tire/wheel system are employed in the modal synthesis model of the vehicle. The Vibration characteristics of a passenger car wheel play an important role to judge a ride comfortability and quality for a passenger car. In this paper, the vibration characteristics of a AI-alloy and steel wheel for passenger car are studied. Natural frequency, damping and mode shape are determined experimentally by frequency response function method. Results show that wheel material property, size and design are parameter for shift of natural frequency and damping.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.72-80
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• 2013

For the proper cooling of in-wheel motor, the cooling channel should have the characteristics which are low pressure drop and adequate cooling oil supply to motor part. In this study, the flow performance of cooling channel for in-wheel motor was evaluated and the shape of the channel was optimized. First, the pressure drop and flow distribution characteristics of the initial channel model were evaluated using numerical analysis. Also, by the result of analysis and design modification, 4 design parameters of the channel were selected. Second, using the Taguchi optimal method, the cooling channel was optimized. In the method, nine models with different levels of the design parameters were generated and the flow characteristics of each models was estimated. Base on the result, the main effect of the design parameters was founded and optimized model was obtained. For the optimized model, the pressure drop and oil flow rate were about 0.196 bar and 0.207 L/min, respectively. The pressure drop decreased by about 0.3 bar and the oil flow rate to the motor part increased by about 0.2 L/min compared to the initial model.

• Proceedings of the KSR Conference
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• 2002.10b
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• pp.787-792
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• 2002

This study presents the wheel wear measurement results of Saemaeul train running on the conventional line. The train set included three different cars which have different shape of wheel profile including KNR and KTX profile currently used in Saemaeul. Train set was operated on Seoul-Pusan line with fixed train set formation for commercial service. Wheel wear measurements were peformed periodically. Here, we describe some results.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.6
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• pp.84-90
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• 2010

This paper presents the shape optimization process for the automotive wheel bearing seal lip using the finite element method and the response surface method. First, to predict performance of the bearing seal lip, we used the non-linear finite element analysis. And then, we compared the analysis results with the test results to verify the finite element model. The objective function in optimizing process was obtained from results of the mud slurry test, which is one of many tests for evaluating performance of wheel bearing. After the mud slurry test for the four models which have the similar cross-sectional shape, we measured the wear area of the seal lip and the moisture content in grease. The objective function has been chosen by comparing the results of mud slurry test and characteristics of seal lip, such as contact force, contact area, contact pressure, and interference. Finally, within limited design parameters, we suggested the optimized shape of seal lip, which is expected to improve the wear and the sealing effect of it.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.6
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• pp.108-113
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• 2007

This study aims to find equivalent comfort contours, reciprocal of frequency weighting curves, for vertical steering wheel vibration. Psychophysical responses were measured from twelve male subjects by using magnitude estimation of relative discomfort due to vertical steering wheel vibrations of magnitude of 0.1 to 1.58 $m/s^2$ in the frequency range of 4 to 250 Hz. Relative discomfort were estimated with a reference vibration of 0.4 $m/s^2$ at 31.5 Hz. Equivalent comfort contours were produced from the median of sensation magnitudes judged by twelve subjects, which showed variation in the shapes with increase of vibration magnitude. A shape of the contour came close to the perception threshold curve with decrease of vibration magnitude. When the vibration magnitude increases, the shape changed close to those in the references of Hong and et al (2003). It is also recommended frequency weighting curves for vertical steering wheel vibration must be expressed as a function of vibration magnitude as well as frequency.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.166-174
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• 2013

This study investigates the strength durability on the results of structural and vibration analysis due to the shape of excavator wheel. As model 2 has the least stress by comparing three models with maximum equivalent stress, model 2 has most durability among three models at static analysis. Maximum equivalent stress is shown at the bottom part contacted with ground and this part on wheel is most affected by load in cases of all models. Safety factor can be decided with the value of 2.3 by considering the yield stress of this model. The range of maximum harmonic response frequencies becomes 6900 to 7000Hz. As model 2 has the least total deformation and equivalent stress at these critical frequencies, model 2 has the most durability at vibration analysis among three models. The structural and vibration analysis results in this study can be effectively utilized with the design of excavator wheel by investigating prevention and durability against its damage.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.3
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• pp.221-229
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• 2001

The mechanical stress due to the wheel-rail contact and thermal stress due to the drag braking increase the incidence of wheel failure. So, firstly, stress analyses(mechanical, thermal and combined stress) of wheel plate are performed using 3-dimensional finite element method(FEM). Secondly, the optimum design of wheel plate ;s investigated in order to reduce weight of the wheel based on results of stress analysis. The optimum design is peformed using 2-dimensional axisymmetric F.E. model and its results are verified by 3-dimensional F. E. model.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.71-77
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• 2007

The surface of railway wheel tread in wheel-rail system can not be free from wear because of various circumstance such as railway condition, maintenance condition, weather condition, characteristics of wheel surface's geometrical shape, and vehicle suspension's structural characteristics etc. Therefore, the research on wear reduction and maintenance method are very important to ensure the safety of railway vehicle, to improve car comfort and to decrease maintenance cost. In this study, the wear rates of railway wheel have been periodically measured in terms of the running distance of Electrical Multiple Unit which have been currently operated and the microstructure transformation of wheel tread using replication method have been performed. The results show that the relations between the flange wear and tread microstructure are depended on running distance and it will supply basic data on wheel maintenance.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.351-356
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• 2000

The mechanical stress due to the wheel-rail contact and thermal stress due to the drag braking increase the incidence of wheel failure. So, firstly, stress analyses(mechanical, thermal and combined stress) of wheel plate are performed using 3-dimensional finite element method(FEM). Secondly, the optimum design of wheel plate is investigated in order to reduce weight of the wheel based on results of stress analysis. The optimum design is peformed using 2-dimensional axisymmetric F.E. model and its results are verified by 3-dimensional F. E. model.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.5
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• pp.165-172
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• 2001

Wheel bearing units were almost exclusively used for car front wheel, where the two ball rows are directly side by side with integrated rubber seal. The seal is of important for wheel bearing units due to the adverse environmental conditions with mud and splash water. The seal of wheel bearing units was designed to have geometry with multi lips, which elastic lip contacts and deforms with bearing. The equation of reaction force for deformed lip as cantilever beam was previously used for seal lip design. But it's result was not useful because deflection of the beam differs from lip's. In this study, deformed shape of the lip was assumed to and order function which is more similar to lip deformation and made the equation for reaction force prediction. The Reaction forces from each other equations were compared with results by FEA to prove usefulness of new equation.