• International Journal of Automotive Technology
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• v.8 no.1
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• pp.59-66
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• 2007

High frequency excitation terms in a cam profile can excite vibration of a cam follower system. In this paper, modified smoothing spline curves are used to reduce the high frequency terms. The essential difference between the proposed method and other existing approaches is its ability to make the principal cam motions smooth while still exactly satisfying boundary conditions of follower displacement, velocity and acceleration. The boundary values usually depend on the ramp properties of a cam. Our method, thus, allows designers to smooth the existing cam motion without any damages on its ramp areas. Because the ramp height, velocity and acceleration are maintained exactly, more radical smoothing is possible. An example shows that the proposed method can be a powerful tool of cam profile smoothing, which removes high frequency components in the cam profile excitations without any changes in ramp properties.

• 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.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.1
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• pp.58-64
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• 2006

This work focuses on reducing the noise and vibration levels of an LPi fuel pump, which are generated from the dynamic motions of pump elements and non-uniform flow of fuel. The noise and vibration levels increase as the revolution speed of the cam goes up. The fuel pump consists of five cavity cells, plungers and diaphragms, which are driven by the cam. The optimal design of the cam profile is performed to decrease the accelerations of moving Parts and to obtain a smooth hydraulic force through a dynamic analysis of a cam-plunger mechanism. The cam-Plunger with a cavity is modeled as a 2 degrees of freedom system having non-linear contacts, the cam profile being represented in terms of Fourier series in order to determine the optimal shape of the cam. From the optimized cam Profile, the acceleration of the diaphragm is reduced in $78\%$, the hydraulic force becoming smoother in case that the hydraulic force is rapidly dropped.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.531-536
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• 1994

Wrapping machines in cigarette factories are equipped with indexing drive units with roller gear cam. At present there are no simple, visual, diagnostic techniques for predicting failure in these nits at an early stage. This paper proposes that failure could be predicted by using either a modified version of kurtosis, or the Wigner distribution method. The nonlinear vibration model proposed in this paper takes into consideration the play between the m and the cam follower, and precisely simulates the actual vibration. Statistics on the variance in play, obtained from the data on time history, call then be used to evaluate the effects of tile mage oil the cam and cam follower.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.04a
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• pp.206-211
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• 1998

This paper presents the deformation characteristics of cam ring in a balanced type vane pump. Cam ring is operated in the condition of high pressure. Therefore the local deformation of cam ring affects the characteristics of compression, vane motion and noise and vibration. We analyzed the deformation of cam ring in three types by using the finite element method. As results of analysis, deformed shape of cam ring and the effects of deformation on the compression are presented.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.3
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• pp.104-110
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• 2006

It is a study on the design of a cam profile for diesel engine SOHC. It is used a reverse engineering method without the usual copy processing. It draws up the contour data from an actual cam and processes by CNC. The profile of the cam is reappeared to be up to operational specifications that are the opening and shutting time, lift, speed and acceleration of the inhalation and escape valves. While the cam operating, the noise and vibration are occurred by the sudden change of speed. The new design of cam profile is suitable fur the valve operations to be smooth. We propose the design method of a cam profile far the reappearance of an actual cam. It is proved to be the propriety about the design of the cam profile through the processing, measurement, and comparison of the cam profile.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.341-346
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• 2014

Intake E-CVVT noise, generally caused by collision sound of roller and cage clearance at idle and driving condition, is considerable source of annoyance in passenger cars using the gasoline engine. Main source of this noise is the cam torque variation of an intake E-CVVT system, and can be controlled by clearance decrease such as backlash reduction, but which may increase the manufacturing cost. Thus in this paper, most effective solution for low noise intake E-CVVT was achieved through not only reduction of backlash and cam angular acceleration but also improvement of vehicle transfer system, which is optimal configuration through acoustic sensitivity optimization of engine mount support bracket.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.10
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• pp.69-77
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• 1995

This laser measurement system has been developed using He-Ne laser and photodiode. The laser beam intensity transmitted on a photodiode was disturbed by eccentrically rotating disk cam with various speeds. The photodiode and an amplifier were used to change the detected beam intensity into voltage. The digitized data through the developed system were recorded on a micro-computer by using a signal analysis program. Its reliability was ascertained by using FFT analyzer. The vibration of rotating disk cam can be analyzed by measureing the intensity change of laser beam which the results by FFT analyzer were similar to. The amplifier was devised to be able to modulate the fluctuations of laser beam. The voltage could be linearly recorded with the change of the laser beam intensity.

• Tribology and Lubricants
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• v.14 no.3
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• pp.59-64
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• 1998

This paper presents the deformation characteristics of cam ring in a balanced type vane pump. Cam ring is operated in the high-pressure condition. Therefore the local deformation of cam ring affects the characteristics of compression, vane motion and noise and vibration. We analyzed the deformation of cam ring for the three types by using the finite element method. The deformed shape of cam ring and the effects of deformation on the compression are presented. As a result of analysis, we know that the right hole of the cam ring has advantage for reducing the pressure overshoot.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.2
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• pp.283-289
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• 2012

Cam rack pinion (CRP) system which consists of cam rack and roller pinion transforms the rotation motion into linear one. The roller pinion has the plurality of rollers and meshes with its conjugated cam rack. The exact tooth profile of the cam rack and the non-undercut condition to satisfy the required performance have been proposed by introducing the profile shift coefficient. The load stress factors are investigated by varying the shape design parameters to predict the gear surface fatigue limit which is strongly related to the gear noise and vibration at the contact patch. The results show that the pitting life can be extended significantly by increasing the profile shift coefficient.