• Journal of Power System Engineering
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• v.21 no.4
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• pp.77-83
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• 2017

The aim of this paper is to solve the chattering and delayed response problems caused by gear backlash. In the gear mechanism based systems, for example, in robot systems, the actuators provide the reduction gear with motors to transfer effectively electric power to mechanical power. Therefore, the gear backlash exists and is an unavoidable fact which makes many undesirable problems. In this paper, the authors try to make a solution for this issue and, introduce several control methods which are PID only, PID with Smith predictor and super-twisting algorithm based SMC(sliding mode control). Each control method is applied to the real plant in which strong backlash is included. By comparison results, it is clear that SMC gives the best control performance with little backlash effects. Also, the usefulness and effectiveness of proposed control method is verified by experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1589-1592
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• 2003

Automatic grease lubricator of gear type was developed by mechanical design, analysis and test with products manufactured by rapid prototyping machine. The mechanism of gear driving was designed in similar to the watch mechanism and lubrication could be controlled by PCB circuit. The body of the lubricator was analyzed by stress analysis with different constructed angle. Digital mockup was analyzed and RP products were combined with PCB circuit and grease. RP products and injection moulding products were tested and compared for roughness and roundness, Finally the grease was drained out for testing the time.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.2
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• pp.272-276
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• 2014

In this paper, cable drive mechanism is proposed to implement high reduction gear ratio. Cable drive mechanism has great advantages such as light weight, high degree of freedom about design aspect and zero backlashes. However, it is restrictively utilized for robotic applications because it is difficult to implement high reduction gear ratio more than 10 to 1. Proposed mechanism enables multi-level reductions by adopting seamless winding method (SWM) which links the previous output axis and the next input axis. Consequently, this reduces the mechanical complexity significantly and enables high reduction with only one single wire cable. 3D CAD design was provided and prototype was manufactured.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.5
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• pp.702-707
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• 2012

This paper considers two linear drive systems using roller gear mechanism(RGM), one is the RRP(roller rack pinion) system that consists of a roller rack and a cam pinion, the other is the CRP(cam rack pinion) system that consists of a cam rack and a roller pinion. Through the comparison of contact forces and load-stress factors between two linear drive systems, it reveals that the RRP system is superior to the CRP system in the aspect of the bending strength, while the CRP system has higher contact fatigue resistance than that of the RRP system.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.7
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• pp.141-146
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• 2002

In this paper, we developed an automated program for the design and machining of spiroid bevel gear, A computer program employing the theory of gearing between gear and pinion is developed to design spiroid bevel gear mechanism. A new method fur machining spiroid bevel gears is proposed, and effectviely used for two examples.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.2 s.179
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• pp.199-206
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• 2006

Automatic grease lubricator is equipment that provides adequate amount of fresh grease constantly to the shaft and the bearings of machines. It minimizes the friction heat and reduces the friction loss of machines to the least. This research is to develop automatic grease lubricator by gear driven mechanism with controlled operation time. The ultimate design of this equipment is to lubricate an adequate amount of grease by a simple switch clicking according to the advanced set cycle. The backlash of the gear was minimized to increase the output power. To increase the power of gear mechanism, the binding frequency and the thickness of the coil were changed. To control the rotating cycles of the main shaft according to its set numbers, different resistance and chips were used to design the circuit to controls electrical signals with pulse. The body of the lubricator was analyzed by stress analysis with different constructed angle. The stress analysis for differing loading pressures applied to the exterior body of grease lubricator due to the setup angle, was found that the maximum stress was distributed over the outlet part where the grease lubricator suddenly narrowed contracts. Digital mock-up was analyzed and the rapid prototyping(RP) trial products were tested with PCB circuit and grease. The evaluation of the outlet capacity for RP trial products was conducted, because the friction caused by the outlet on the wall surface was an important factor in the operation of the equipment. Finally, the finishing process was applied to decrease the roughness of the surface to a comparable level and was able to test the performance examination for the product.

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.1
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• pp.43-55
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• 2001

A continuously variable transmission(CVT) mechanism composed of one differential gear unit and one continuously variable unit(CVU) can be classified according to the coupling of CVU and the direction of power flows. The mechanism has many advantages which are the decrease of CVT size, the increase of overall efficiency, the extension of speed ratio range and generation of geared neutral. The CVT mechanism considered here is the input coupled type which combines the functions of a 2K-H I type differential gear unit and a V-belt type CVU. One shaft of the CVU is connected directly to the input shaft and another shaft of it is linked to the differential gear unit. It is shown that some fundamental relations(speed ratios, power flows and efficiencies) for twelve mechanisms previously described are valid by various experimental studies, six of them produce a power circulation and the others produce a power split. Some useful comparisons between theoretical analysis and experimental results are presented. General properties also are discussed, which connect following power flow modes : (a) power circulation mode; (b) power split mode.

• Tribology and Lubricants
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• v.8 no.1
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• pp.24-29
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• 1992

Friction and wear characteristics of gear oils added load carrying aditives, JS and DBP have been invesitigated using Shell Four Ball Tester and Cygnus and also compared with commercial gear oil. The Gear oil added DBP among them showed excellent friction and wear performances, which is deduced by action mechanism of additives. The surface analysis of the worn balls was conducted using an optical microscope.

• Journal of Drive and Control
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• v.10 no.2
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• pp.30-36
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• 2013

Tractor is a farm vehicle that is designed to provide a high tractive effort at low speed. It is used for versatile agricultural tasks such as hauling a trailer, tillage, mowing and construction work. Most older tractors use a manual transmission. However, as the intensity of work increases, tractors equipped with automatic transmission become popular due to the work convenience. In order to give the operator a large degree of control in field work, 24 gears with automatic 8-speed and manual 3-speed are arranged in transmission. This paper deals with the gear train that is designed for 8-speed automatic transmission by the engagement of multi-disk clutches. The gear ratio for each speed as well as power transmission mechanism is analyzed through velocity analysis. In addition, constraints of mesh gear ratio are derived by investigating the power flow path in velocity diagram for the given 8-speed gear ratio.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.722-727
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• 2004

The gear that is used in various mechanical components occurs easily damages due to the repeated torque and the high oil temperature. The main failure mode of the gear is the surface deterioration with the tooth surface fatigue. Therefore, the life evaluation and the failure analysis of the gear were very important since it may cause fatal damage of entire gear box system. In this paper, the failure mechanism and the life of the gear were evaluated using the durability analysis simulator such as MSC.FATIGUE. Moreover, the reliability analysis model of the spur gear with the accelerated life testing technique was proposed.