• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.1186-1195
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• 1993

The Japanese type combine harvester has adopted rubber crawlers for the driving mechanism from first production . However, combine harvesters with movable track rollers in the rubber crawler system have been adopted recently for the purpose of stability at the time of climbing over the footpaths between rice fields, as the results of the machines becoming large. However, the dynamic characteristics of movable track rollers have not been clarified. For this reason, the design of movable track rollers depends on trial and errors. It is known that vibration characteristics of the vehicle with movable track rollers are different from the vibration characteristics of the vehicles with fixed track rollers even though the track roller arrangements are the same. Therefore, the theoretical analyses of movable track rollers must be hurried in order to formulate a reasonable track roller arrangement design. the authors have studied the vibration characteristics of the rubber crawler ve icle with fixed track rollers. in this study, the dynamic model of the vehicle with movable track roller sis compared with the dynamic model of the vehicle with fixed track rollers. Next, motions are simulated to analyze the movable track rollers by expanding the motion equation which were constructed for the dynamic model of the fixed track rollers.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.829-834
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• 2003

Many types of omnidirectional wheels with passive rollers have gaps between rollers. Since these gaps cause a wheel to make discontinuous contact with the ground, they lead to vertical and/or horizontal vibrations during wheel operation. In addition, the radii of passive rollers are related to the height of a bump an omnidirectional wheel can surmount. In this research a new design of the alternate wheel is proposed. Because this wheel makes continuous contact with the ground and has alternating large and small rollers around the wheel, it is termed a continuous alternate wheel (CAW). In this paper a design procedure is also presented to determine the optimum number of rollers, the radii of rollers and the inside inclination angle of an outer roller for given design specifications. The CAW based on this design is compared to the existing alternate wheels in terms of design. Finally, an actual continuous alternate wheel is constructed to verify validity of the design guidelines.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.107-114
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• 2000

Rollers and rolls in the continuous process systems are noes of key components that determine the quality of web products. The condition of rollers and rolls(ex. eccentricity wear) should be consistently monitored in order to maintain the process conditions (ex. tension, edge position) within a required specification. In this paper, a new diagnosis technique is suggested to detect the defect of rollers/rolls (ex. eccentricity, wear) based on frequency domain analysis of web tension signal. The kernel of this technique is to use the spectrum amplitude of tension signal which allows to identify the fault rollers/rolls and to also diagnose the degree of fault in corresponding rollers and rolls. The experimental results proved that the suggested diagnosis technique can be successfully used to identify the defect rollers and rolls as well as to diagnose the degree of the defect of those rollers. The suggested technique can be applied to monitor and diagnose the shape of rollers and rolls in various multi-span web transport systems.

• Journal of Mechanical Science and Technology
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• v.16 no.12
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• pp.1604-1612
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• 2002

Rollers in the continuous process systems are ones of key components that determine the quality of web products. The condition of rollers (e.g. eccentricity, runout) should be consistently monitored in order to maintain the process conditions (e.g. tension, edge position) within a required specification. In this paper, a new diagnosis algorithm is suggested to detect the defective rollers based on the frequency analysis of web tension signals. The kernel of this technique is to use the characteristic features (RMS, Peak value, Power spectral density) of tension signals which allow the identification of the faulty rollers and the diagnosis of the degree of fault in the rollers. The characteristic features could be used to train an artificial neural network which could classify roller conditions into three groups (normal, warning, and faulty conditions) The simulation and experimental results showed that the suggested diagnosis algorithm can be successfully used to identify the defective rollers as well as to diagnose the degree of the defect of those rollers.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.7 s.172
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• pp.155-163
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• 2005

Pressure heating rollers with temperature control were mounted to a flat cable laminating machine (FCLM). Pressure heating rollers should be heated up to the setting temperature $(175^{\circ}C)$ and kept on to producing good quality flexible flat cables (FFC). Existing Pressure heating rollers took more than 70minutes to the setting temperature and did not keep on the setting temperature in production. Temperature controller, electric power controller, material and diameter of rollers and heat capacities were changed to improve the temperature control of the pressure heat rollers for better production of the FFC. Thus, the reaching time to the setting temperature (RT), temperature stability time (TST) and temperature hunting (TH) were measured and compared with the existing pressure rollers case. The RT of A roller was shortened by 50minutes, and B roller was shortened by 15minutes. The TST of A roller was shortened by 13minutes, and B roller was shortened by 15minutes. The THs of both A and B rollers were settled up to ${\pm}5^{\circ}C$. Finally, the productivity of the FCLM and the quality of the FFC were increased.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1159-1162
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• 1995

In the continuous process systems, traction between a moving web and rollers is one of key mechanisms for the study of major issues including the distributed control of tension, guiding, wrinkling, and scratching. Energy is transferred from the driven rollers to the web and from the web to the idle rollers through traction. The characteristics of friction plays a major role in the determination of the traction force between the moving web and the rollers. In this paper, a procedure to determine the frcition coefficient between the moving web and rollers is devoloped. An experimental setup to validate the procedure is devised. Experimental results showed that the value of traction coefficient decreases as the operating web speed increases and increases as the operating web tension and wrap alngle increase.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.8
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• pp.31-39
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• 1996

In this paper, the error and its sources in manufacturing of bourdon tube pressure gage was studied, and the method to reduce such errors was discussed. In more detail, the effects of parallelism of rollers, spring back, uniformity of radius curvature and the ratio of circumferential speeds of rollers were invesrti- gated. As a reselt, we could find out that the aprallelism of roller affected to the displacement error at the free end of gage and that the amount of spring back was closely related with the ratio of circumferential speeds of rollers. The uniformity of curvature radius was determined by the distance between bending rollers and it was comparatively uniform in the range above 30 .deg. C from the both sides of tube. Also, the ratio of circumfer-ential speeds of rollers was finded out as a very important factor giving severe influence on the creep or the hysteresis of bourdon tube.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.681-685
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• 2004

A media-feeding (or media-transport) system is a key component in daily consumer systems such as printers, copiers and ATM's. The role of the media-transport system is to feed a medium, which is usually in the form of a thin film, to the main process in a uniform and repeatable manner. Even small slippage between the media and the feeding rollers could significantly degrade the performance of the entire system. The slippage between the medium and the feeding rollers is determined by many parameters which include the friction coefficient between the feeding rollers and the medium material, the angular velocity of the feeding rollers, and the normal force applied by feeding rollers on the medium. This paper investigates the effect of the normal force and the angular velocity of feeding rollers on the slippage of the medium. Authors have constructed a test bed for experiments, which consists of a feeding module and various measuring devices. Using regular paper as media being fed, the authors experimentally measured the slippage of the medium under various normal forces and angular velocities of driving feeding roller. Also the authors developed a novel two-dimensional simulation model for the media-transport system. The paper medium is modeled as a set of multiple rigid bodies interconnected by revolute joints and rotational springs and dampers. Simulations were executed using a multi-body dynamic analysis tool called RecurDy $n^{ⓡ}$. The slippage obtained by the simulation is compared to experimental results.ults.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.5
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• pp.165-170
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• 2001

In the continuos process systems, traction between a moving web and rollers is one of key mechanisms for the study of major issues including the distributed control of tension, guiding, wrinkling, winding, and scratching. Energy is transferred from the driven rollers to the web and from the web to the idle rollers through traction. The characteristics of friction play major role in the determination of the traction force between the moving web and the rollers. In this paper the characteristics of friction between the moving web and the rollers are studied. A procedure to determine the friction coefficient between the moving web and rollers is developed. An experimental setup to validate the procedure is devised. Experimental results showed that the value of traction coefficient decreases as the operating web speed increases and increases as the operation web tension increase.

• Journal of Biosystems Engineering
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• v.17 no.3
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• pp.290-296
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• 1992

A prototype calyx-plucking system was designed on the basis of a calyx-plucking method which had been developed in the previous study. This system was composed of a pair of compressive rollers and three pairs of tensile rollers. The performance test for this system revealed that two significant factors of operating conditions were the moisture content of red pepper and the relative velocity between tensile rollers. The newly developed system can be utilized as an efficient calyx-plucking unit in the processing plant for powdering red pepper.