• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.3
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• pp.81-86
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• 2005

The agricultural working tractor of this study is equipped with 4 wheel driving system developed in study 1 and 4-type wheel steering system. The wheel steering system has four type of steering methods that are front wheel steering, rear wheel steering, 4 wheel steering with opposite phase, and 4 wheel steering with corresponding phase. This study introduces the hydraulic circuit of the 4-type wheel steering system and the construction of working tractor. Judging from the field test results of the developed working tractor, it is apparent that 4-type wheel steering system has many advantages when driving in a narrow corral.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.934-939
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• 2004

Railway wheel/rail contact conditions have an influence on dynamic behavior of rolling stock. If there are problems of incompatibility between wheel and rail, damages like wheel wear, wheel spalling, rail wear, etc are occurred. Especially wheel and rail profiles are important factor of vehicle curving performance, so compatibility study between wheel and rail has to be carried out preferentially, In this study, we have analyzed the compatibility between wheel and rail of KNR conventional line to improve the maintenance efficiency of wheel and rail. Thus we showed the results relating to wheel/rail geometric contact, vehicle running performances as the change of wheel/rail combination.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.3
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• pp.11-17
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• 1998

The mecanum wheel was originaly developed in sweden to realize the omni-directional motion of the cart. The circumference of each wheel is lined with rollers set at 45 degrees relative to the main wheel. This paper proves that the roller of the mecanum wheel shapes the ellipsoid, derives the kinematic relationships between the parameters of the wheel and rollers, and proposes the procedure to determine the parameters of the wheel. The result was implemented into the computer program for the design of the mecanum wheel.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1868-1873
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• 2011

In this paper, a theoretical formulation of a simplified wheel-set model for collision-induced derailments was evaluated by numerical simulations for the wheel-climb derailment and wheel-lift derailment types. The derailment types were classified into the wheel-climb derailment and the wheel-lift derailment according to the friction force direction of the wheel-flange. The wheel-climb derailment type was classified into Climb-up, Climb/Roll-over, and Roll-over-C, and wheel-lift derailment type was classified into Slip-up, Slip/Roll-over and Roll-over-L. To verify the theoretical equations derived for the wheel-climb derailment and the wheel-lift derailment, dynamic simulations using RecurDyn of Functionbay and Ls-Dyna of LSTC were performed and compared for some examples. The derailment predictions of the suggested theoretical formulation were in good agreement with those of the numerical simulations. The direction of the frictional force between the wheel-flange and the rail can be well predicted using the suggested derailment formulation at a initial derailment.

• Journal of the Korean Society for Railway
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• v.8 no.5
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• pp.483-489
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• 2005

Railway wheel/rail contact conditions have influences on dynamic behavior of the rolling stock. If there are incompatibility problems between the wheel and rail, damages like wheel wear, wheel spalling, rail wear, etc are occurred. Especially wheel and rail profiles are important factors of vehicle curving performance, so compatibility studies between wheel and rail profiles have to be carried out preferentially. In this study, we have studied the compatibility between wheel and rail profiles of KNR conventional line to analyze the dynamic performances of the rolling-stock. Thus we showed the results relating to wheel/rail geometric contact, vehicle running performances as the change of wheel/rail combination.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.344-349
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• 2005

This paper presents a geometrical error analysis of wheel curve generation method for micro aspheric surface machining using parallel grinding method. In aspheric grinding, wheel wear in process is crucial parameter for profile error of the ground surface. To decrease wheel weal parallel grinding method is adopted. Wheel and work piece (Tungsten carbide) contact point changes during machining process. In truing process of the wheel radius is determined by the angle and distance between wheel and truer. Wheel radius error is predominantly affected by vertical deviation between the wheel rotation center and the truer center Simulation for vertical error and wheel radius error shows same tendency that expected by geometrical analysis. Experimental results show that the analysis of curve generation method matches with simulations and wheel radius errors.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.559-560
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• 2012

• Journal of Biosystems Engineering
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• v.26 no.1
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• pp.1-10
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• 2001

Interactions between cage wheel and soil under the wet paddy field condition were analyzed. The cage wheel as a traction aid to driving tires of tractor was attached to the outside of the tires. The driving torque transmitted only to the cage wheel was measured and its effect on the total driving torque by both the tires and cage wheel was analyzed. Mathematical models were developed to predict the soil thrusts y a single lug and by the cage wheel with many lugs, respectively. Experimental results showed that as the diameter of cage wheel increased, positive effects of the cage wheel on the traction also increased. About 33-40% of the total traction force was obtained by the cage wheel with a diameter 1,182mm and 49-55% with a diameter 1,222mm. The peak thrust of the single lug of cage wheel increased by 31% and 59%, respectively when the diameter of the cage wheel increased from 1,182mm to 1,222mm and 1,262mm. The thrust by the cage wheel was estimated by using the developed mathematical models and the results were proved that the models are reliable for the estimation of the traction by the cage wheels.

• International Journal of Railway
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• v.1 no.2
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• pp.31-36
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• 2008

$DF_{21}$ diesel locomotive was designed to satisfy the requirement of Kunming Meter track and the 2Co self-guided radial bogie was used to suit the complex curve track. There are totally 12 locomotives was served on the track. The first two locomotives were devotion running on the track since April 2003, the wheel tread splling was occurred on the middle wheel set of the two locomotives after running nearly 150 thousands km on the track of the two locomotives at August 2004. The dynamic analysis was carried out to find the reason. The wheel set longitudinal vibration resonance phenomenon was existed on the locomotive dynamic performance, and this was caused by the too big longitudinal stiffness of the journal box bar on the middle wheel set. Wheel set longitudinal vibration resonance maybe an important reason of lead to wheel tread spalling. The corresponding mend methods were put forward from the point of view of wheel set longitudinal vibration resonance. All the wheel tread of the 12 locomotives on the middle wheel set were in good condition and not occurred the wheel tread spalling after the mend till December 2007 after 350 thousands km were finished. The mechanism of the wheel tread splling and corresponding mend method was discussed in detail in this paper.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.184-189
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• 2008

In this study, an artificial wheel load generation method is proposed to assist practical engineers performing dynamic analysis with simple procedure. To generate an artificial wheel loads from running vehicle, PSD(Power Spectrum Density) profiles of actual wheel load were sampled in terms of various road roughnesses. A detailed truck and bridge models were used for sampling actual wheel load to represent the real motion of moving vehicle. These wheel load profiles were simplified for the artificial wheel load. The simplification of actual wheel load profiles was performed by regression analysis. The result showed that the artificial wheel load well represents the real profiles of wheel load.