• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.12
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• pp.1077-1085
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• 2016

Linear roller bearing (LRB) is an important mechanical element that is widely used in precise positioning systems that are subjected to large loads. This paper presents a new model for estimating the displacement of an LRB subjected to external forces. For this purpose, assuming that the linear motion block (LM block) is rigid, the equilibrium conditions for the LRB were obtained by solving the equilibrium equations of the rollers and the rigid LM block using the iterative Newton-Raphson method. The contact loads between the rollers and raceways were determined considering the profiled rollers. Then, the structural deformations of the LM block, subjected to the contact loads from the rigid LM block model, were computed using a finite element model for the LM block. The displacements of the LRB were then determined by superposition of the rigid LM block displacements on the induced displacements due to the structural deformations of the LM block. The proposed method was verified through comparison with a program by the bearing manufacturer.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.125-127
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• 2007

에어 베어링은 높은 강성과 낮은 마찰력과 같은 장점들로 인하여 높은 정밀도를 요구하는 반도체나 디스플레이 장비의 선형 스테이지에 주로 사용 되어지고 있다. 하지만 현재까지 높은 정밀도를 요구하는 회전형 스테이지에는 아직까지 크로스 롤러링을 이용하여 가이드를 하고 있다. 본 논문에서는 높은 정밀도를 갖는 회전 스테이지의 설계를 위하여 구동 성능과 오차요소에 대한 성능에 대해 설계 목표를 제시 하였고 이러한 스테이지를 구현하기 위해 에어베어링을 적용한 회전형 스테이지를 설계하였다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.2
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• pp.181-191
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• 2014

This study aims to evaluate cutter acting forces as well as axial stresses and torques in the shaft of two kinds of disc cutters including a single disc cutter and a double disc cutter with the same cutter ring geometry in a series of linear cutting tests. From the tests, the mean values of normal forces and rolling forces acting on the double disc cutter were approximately twice as high as those from the single disc cutter. Similarly, the mean values of axial stresses in the shaft of the double disc cutter were also twice as high as those from the single disc cutter even though the comparisons of torques from two kinds of disc cutters were insignificant since they showed very low values. However, it is necessary to take the durability of a tapered roller bearing used for the double disc cutter into high consideration since the average normal force from the double disc cutter exceeds the allowable force for a disc cutter with the diameter of 432 mm (17 inches). Finally, there is no practical problem in terms of axial stresses in the shaft of the double disc cutter since they are much lower than the yielding stress of the cutter shaft material, even though the axial stresses in the shaft of the double disc cutter are approximately twice as high as those from the single disc cutter.