• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.532-535
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• 2003

Vibration of rotating machinery is a factor that is something to do with abnormal machinery. Former days, Perception of vibration at rotating machinery had used Shaft rider type. Shaft rider type was adhered to surface of shaft and detected vibration of rotating machinery. Recently, Perception of vibration at rotating machinery uses to non-contact sensor. Working principle of non-contact sensor is used of eddy current. Vibration at rotating machinery appears to deviation of eddy current. In this paper, We investigate abnormal vibration due to non-contact sensor.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.309-313
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• 2006

Many researchers have studied on the lightness of automobile. These researches are such as a body shell, sub frame, fuel tank, engine etc. The transmission Part is a magnitude one in the aspect of weight. A drive shaft (propeller shaft) transmits the engine power to rear differential gear assembly. It is used in the compact car that is a single drive shaft. But in the case of long body cars such as SUV (Sports Utility Vehicle), truck and large vehicle, two or three divided drive shaft are used to prevent the vibration damage from a drive shaft that has been taken high torsion and rotation. This multi-divided drive shaft structure is so heavy because it is assembled by yoke, center bearing and solid spline axis. When the rear axle move up and down, the spline shaft adjust the variation of a length between the transmission and rear axle gearbox. In this paper, it is studied in the experimental method that is a bending vibration characteristic of slip in tube shaped propeller shaft. This type propeller shaft is developed to combine the spline axis with drive shaft and can be light in weight of transmission part.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1997.10a
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• pp.123-128
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• 1997

In-situ bearing metal temperature and shaft vibration are measured for an unload type and a preload type, m=0.87, of vertical guide bearing for hydraulic pump-turbines. Guide bearing is a tiltingpad type journal bearing consisting of eight pads whose diameter is 1,450 mm. Rotational speed is 450 rpm. Both the bearing metal temperature and the shaft vibration are very high in the unload type but are slight in the preload type, comparatively. The bearing metal temperature is decreased due to the increase of cooling effect by the increase of preload and the shaft vibration is decreased due to the increase of bearing stiffness. It is concluded that the preload effect of a guide bearing for hydraulic pump-turbines has a large influence on the bearing metal temperature and the shaft vibration.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.2
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• pp.161-169
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• 2002

Based on the analytic expression for the elasto-dynamic behavior of rotating shaft, the transfer matrix is formulated for the shaft element with uniform cross-section. Timoshenko beam theory is Introduced for modeling the behavior of shaft. Complex variables representing the displacement, slope, moment and shear force are used for deriving the transfer matrix between both ends of the shaft element. Simulation result obtained by applying the transfer matrix to a general rotor model is compared with the reference result and proved to be exact. Natural frequencies and the corresponding modes are analyzed with varying the bearing: stiffness. The generally used bearings are considered for discussions. and the bearing stiffness is shown to affect the vibration characteristics of rotor.

• Journal of Power System Engineering
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• v.13 no.1
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• pp.33-38
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• 2009

In this study, the nose of cam in the automobile engine was modelled into circular disk to analyze the torsional vibration of the cam shaft. The distance between disks was fixed, but the diameter of disks was changed. The torsional vibration of the cam shaft was studied experimentally by the motion of the modelled disk with changing the disk diameter. And the sizes of the modelled disk were selected not to show the natural frequencies over all the experimental ranges. The torsional vibration meter used in this study has a laser system with non-contact measurement method, which can measure both torsional angular vibration velocity and torsional angular vibration displacement simultaneously. The Experimental analysis shows that the characteristics of the torsional vibration in the horizontal rotating shaft can be considerably affected by the arrangement of the modelled disks.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.314-319
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• 2006

Main focus on balance shaft module is to reduce the vibration triggered from engine block and compensate it from unbalance mass in balance shaft. Since the performance of balance shaft module is controlled by rotor shape including unbalance mass, a design strategy on rotor is key issue on determine the quality of balance shaft system. Even the design result on balance shaft mostly affect the lay-out of housing and other related components, its issue on balance shaft should be considered in advance throughout the total design procedure. In this paper, optimal design strategy focused on balance shaft is presented to make a design process efficiently with ensuring its high performance. And its method is verified with field design process of balance shaft in commonly adapted vehicle with 3-cylinder and 4-cylinder engine.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.3
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• pp.274-281
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• 2009

The carbon fiber epoxy composite material and aluminum have many advantages over other materials because of their high specific stiffness and good fatigue characteristics. Basically, the propeller shaft of automobile requires bending frequency of higher than 2,700 Nm and high natural frequency of higher than 9,200 rpm occurred by fast revolution. For this reason, natural frequency and torsion torque characteristics of hybrid shaft was studied in variation of its outer-diameter and thickness. Vibration and torque characteristics of hybrid shaft were compared by torsion tester, natural frequency experiments and FE analysis. Designed hybrid shaft satisfied its vibration and torque characteristics when its outer-diameter was 60 mm and thickness was 5 mm. Therefore, hybrid material enables to manufacture one piece structure hybrid propeller shaft rather than current two piece structure.

• Journal of KSNVE
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• v.10 no.4
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• pp.596-601
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• 2000

Propeller shaft is one of the main excitation source in the vehicle driveline. This paper presents the correlation of the propeller shaft and axle vibration. 10 D.O.F. lumped mass model is constructed to simulate the dirveline. Experimental apparatus is constructed to verify the simulation model and to measure the vibration signal of lthe driveline. The results of simulation and experiments show that propeller shaft excitation is 2nd harmonic of the rotational frequency. Axle housing vibration signal shows that axle resonate with 2nd harmonic of excitation frequency due to universal joint effect.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.11 s.104
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• pp.1268-1275
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• 2005

Vibration in Engine module could be reduced by introducing a balance shaft module which has one or more unbalanced rotors. Since the unbalanced rotor is installed in an opposite direction of the free force or unbalance moment by engine component, the unexpected vibration could be decreased kinematically. The essential equation of the unbalanced rotor was Presented for two cases, 3 in-line and 4 in-line cylinder engine type, And the efficiency of the balance shaft is investigated by the vehicle testing that is focused on measuring the reduced vibration level when adapting a balancing module. With the signal processing of measured signals, some important issues on design the balancing shaft could be derived and the overall design process is explained in the final part including the peripheral component, i.e. housing and bush.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.99-104
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• 2008

The Carbon fiber epoxy composite material and aluminum have many advantages about higher specific stiffness and good fatigue characteristics. basically, the propeller shaft of automobile must satisfy high natural frequency more than 9,200 rpm to satisfy high number of rotation and high torsion torque more than 2,700Nm. In these reason, studied natural frequency and torsion torque characteristics of shaft according to parameter variations with the outdiameter and thickness. From the torsion tester and natural frequency experiments FE analyses was compared vibration and torque characteristics of hybrid shaft Designed hybrid shaft was experimented through FFT analyzer and torsion tester each and satisfied that hybrid shaft reverence 60mm and thickness 5mm by a these experiment is most suitable. Therefore, that can manufacture existent steel two piece type propeller shaft to one piece type hybrid shaft.