• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.2
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• pp.46-52
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• 2004

The most of reducers consist of many gear parts, but a ball reducer never contains a gear. As the ball reducer with gearless has no back lash, it is necessary more and more to precision machine. The reducing of ball reducer happens by cycloid curves and all instant relative velocity centers always pass on a given constant position when rotational running. Then, it is difficult to calculate cycloid curve for design and machining. So, this paper studied a software for the design of the ball reducer design and machined all parts included among cycloid curve. By using the developed software, this study has large benefit to design every ball reducer.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.289-295
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• 1999

A new conceptual wave rolling ball reducer was proposed and investigated. The main components of the reducer were a eccentric input shaft and bearings, followers with balls, a flange, and a outer ring with waved groove. Followers moved along the holes of the flange according to the rotation of the shaft. And the balls installed in tips of followers were rolled with the waved groove of outer ring. When the shaft was rotated as one revolution and the outer ring was fixed, the flange was rotated as one wave. The kinematic analysis of the reducer carried out. The forces of each components were estimated, and the main design parameters were investigated. The design program using Visual C++ and Auto Lisp to determine the design parameters and to generate the drawing sheet.

• The Journal of Korea Robotics Society
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• v.19 no.3
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• pp.229-235
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• 2024

This research focuses on reducers, vital components in service robots, with a special emphasis on friction reducers designed for use in environments where interaction with humans is essential. For service robots to effectively perform advanced tasks, it is crucial to have reducers that offer high precision, high reduction ratios, and strong resistance to impacts. To meet these requirements, our study introduces a new design methodology and proposes a friction reducer featuring a multi-layer ball array structure. Compared to traditional gearbox-based reducers, the friction reducer developed in this study demonstrates a higher reduction ratio and improved shock absorption. The performance of this newly proposed reducer has been verified through experimental analysis. It was confirmed that by minimizing drive losses, the system has high backdrivability, delivering a torque of 15 Nm. Additionally, it was observed that the system showed an immediate response without backlash to fine input vibrations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.540-543
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• 2002

Conventional robot manipulators actuated by motors with the speed reducer such as the harmonic drive have weakness in the load capacity, since the speed reducer does not have enough strength. To overcome this, we proposed and constructed a new type of the robot actuator which is four-bar-link mechanism driven by the ball screw. We developed a new type of a revolute-jointed robot manipulator composed of four axes. The base axis is actuated with conventional speed reducer, but the others are actuated by the proposed actuators. We analyzed the mechanism of the actuators of the robot joints, and developed the dynamics model. The dynamics are expressed in the joint coordinates, and then they are mapped into the sliding coordinates of the ball screw. The structure specifications of the manipulator shown.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.5
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• pp.539-546
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• 2004

Conventional robot manipulators actuated by motors with the speed reducer such as the harmonic drive have weakness in the load capacity, since the speed reducer does not have enough strength. To overcome this, a new type of the robot actuator based on the four-bar-link mechanism driven by the ball screw was proposed and constructed. Also, a new type of a revolute-jointed robot manipulator composed of the developed actuators was developed. The base axis is actuated by the motor with the conventional speed reducer, but the other axes are actuated by the proposed actuators. The kinematics and dynamics of the robot were analyzed, and the performance test of the robot was made. Through the test results, the performance of superior load capacity versus the robot weight is shown.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.05a
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• pp.143-149
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• 2002

Ball reducer with waved grooves has many advantages over other reducers for the high-reduction ratios, low noise and low energy loss, etc. The mechanism of force transmission is very similar to that of cam and follower in automobile valve train system especially in the contact geometry. In this study, we have investigated the traces of contact between ball and outer race and the working behaviors with a certain reduction ratio. In order to verify the contact behaviors between ball and outer race, which determines the critical endurance life the contact velocity and load are computed for a cycle. During some period of a cycle, the contact velocity reverses its direction very suddenly, which causes undesirable endurance performance of this machinery. From the computational investigation in this work, we hope to predict similar contact damages in other machinery due to this kind of contact behaviors, which is very common in many contact phenomena.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.292-295
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• 2001

Conventional robots actuated by motors with the speed reducer such as harmonic drive had weakness in delivering loads, pressing, grinding, and cutting jobs. To overcome this, a new type of robot actuated by the ball screw was proposed. The ball screw is actuated by using four bar mechanism. The dynamics model of the robot was set up. The robot has parameter uncertainties and nonlinearlity due to the ball screw actuator. To coordinate the robot, the sliding-mode control was applied.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.323-326
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• 1997

Conventional robots actuated by motors with the speed reducer such as harmonic drive had weakness in delivering loads, pressing, grinding, and cutting jobs. To overcome this, the developer a new type of robot actuated by the ball screw. The robot is an articulated shape, which is composed of four axes. The base axis is actuated similarly with conventional robot, but the others are actuated by four bars mechanism composed of the ball screw. We setup the dynamics model of the robot. The robot has parameter uncertainties and nonlinearlity due to the ball screw actuator. To coordinate the robot, we applied sliding-mode control.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.2
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• pp.238-245
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• 2003

To overcome the weakness in the load capacity of conventional robot manipulators actuated by motors with the speed reducer such as the harmonic driver, we proposed a new closed-chain type of the robot actuator which is composed of the four-bar-link mechanism driven by the ball screw. The robot manipulator is revolute-jointed and composed of four axes. The base axis is actuated by the lineal actuator such as the ball screw, and the others are actuated by the proposed actuator. We analyzed the mechanism of the actuators of the robot joints, and developed the dynamics model. The dynamics are expressed in the joint coordinates and then they are mapped into the sliding coordinates of the ball screw. We performed fundamental tests on the structure of the robot.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.583-586
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• 2000

The conventional actuators with the speed reducer had weakness in supporting the weight of the body and leg itself. To overcome this, a new four bar link mechanism actuated by the ball screw was proposed. The four bar mechanism has higher strength and gear ratio than the conventional actuator to actutate the leg of the biped robot. One leg was designed to have ankle, thigh, and hip joints. The kinematics and dynamics of one leg with four bar link mechanism was analyzed using Euler-Lagrange approach. The dynamics of one leg was expressed in the ball strew frame.