• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.11
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• pp.2049-2058
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• 1992

In this work, a 6 degree of freedom lumped mass model is constructed for an OHC-type cam valve train analysis, and the model is verified experimentally. Using the verified model, an optimum cam profile is designed to minimize the maximum contact force between cam and follower under the constraints such as cam lift and cam event angle. The designed cam was carefully machined and tested experimentally. As operating the designed cam shaft on the test rig, the valve motion was precisely measured with laser displacement meter and the contact force was indirectly monitored by measuring strain at a certain point of the finger follower. Judging from the model simulation and experiment results, the maximum contact force can be reduced as much as more than 16.7 percent under maintaining the original valve flow area by adopting the optimum cam profile.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.3
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• pp.788-795
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• 1996

In this paper, and optimum profile of a cam being used in a VTR Deck mechanism is designed by the response surface analysis. The objective function of the design is to reduce driving torque of the pinch roller system that is used to compress video tape to the capstan motor axia. The pinch roller system that will be designed is modeled using the general purpopse mechanism analysis program DADS. The computer model is compared with the physical system for reliability. A model function to represent relationship between design variables and the objective function is estimated by the response surface analysis. Once the model function is reliably estimated the optimal design is carried out using the model function and each design variable's boundaries. To verify improvement of the pinch roller system, a prototype for the pinch rooler system is made and tested. From the test result, an optimum cam profile to resuce driving torque of the pinch roller system is verified.

• 연구논문집
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• s.28
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• pp.89-100
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• 1998

This paper deals with the design and analysis of a beating cam. The beating device of a high speed rapier loom, weaving fabric by completion of warp-weft patterns, is driven by double cam type on the same axis. As the double cam, coupled with two cams, performs the mutual conjugate motion, the double cam must be very preciously designed for smooth. For the shape design of a double cam, an instant velocity center method is proposed. This method can determine the cam profile from the contact conditions of the cam and roller follower and the velocity relationships at the instant velocity center. And the practical applicability was verified by developing “DISKCAM of a CAD program. As the results in this paper, the shapes of two cams, which are in the conjugate motion, are designed by instant velocity center method. We applied 8-order polynominals for the beating as displace¬ment curves for shape determination of double cams. The data of displacement, velocity, and acceleration of beating cam can be used adjust in accurate operation and to develope an advanced beating device.

• Tribology and Lubricants
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• v.20 no.3
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• pp.157-162
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• 2004

The cam curve of a balance type vane pump consists usually of circular arcs and Archimedes' spirals. However, if they are connected directly together, the curve must have a few discontinuous points of the gradients and the motion of the vanes is no longer smooth. Designing data for an oil hydraulic vane pump used in power steering system were obtained by the acquisition of optimum cam profile data which can be available to reduce noises and vibrations through the minimization of cavitation with the improvement of suctional performance. The performance test is carried on the trial manufactures by measuring the volumetric and the mechanical efficiency. And from that result, maintaining the same characteristic as the conventional one in the relief pressure and noise level, the experimental pump discharges 0.7 $\ell$/min and shows nearly 3.5% enhancement in the total efficiency more than the conventional one.

• Journal of Drive and Control
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• v.10 no.3
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• pp.7-13
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• 2013

Hydraulic vane pumps are widely used in various hydraulic systems because of its compactness and light weight. It is well known that the vanes and cam ring are separated by very thin liquid films which result in the EHL state. Contrary to the case of cylindrical roller bearings, the inlet and side boundary pressures are much higher than the atmospheric pressure. In this paper, a numerical solution of the EHL of finite line contacts between the cam ring and vane tip with profiled ends is presented. Using a finite difference method with non-uniform grids and the Newton-Raphson method, converged solutions are obtained for moderate load and material parameters. The EHL pressure distribution and film shape are considerably affected by pump delivery pressure and the side boundary condition applied. Both the maximum pressure and the minimum film thickness always occurred near the edge regions. The present results can be used in the design of optimum vane profile in hydraulic vane pump.