• Journal of the Korean Society for Precision Engineering
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• v.20 no.8
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• pp.166-174
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• 2003

Hydrostatic bearings are widely used in precision machines due to their high motion guide accuracy, low friction and high load carrying capacity. It is very useful to estimate the moving characteristics of hydrostatic bearings in the design stage. A new method is suggested for the analysis of fluid film in hydrostatic bearings. A combined mesh of 8 node solid elements with negligible deformation resistance and spring-dashpot elements is used in conjunction with the user subroutine of ABAQUS to represent the fluid film. The mesh can be used to capture the deformation of the bearing structure as well as the varying properties of fluid film. Analysis results from the finite element model are compared with theoretical solutions, results from FLUENT analysis and some previous works. With this method, static and dynamic analyses of the system containing the bearings can be performed efficiently.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.712-717
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• 2000

Hydrostatic bearings have been applied to high precision machine tools and instruments, because the bearing has high stiffness, high damping and excellent straightness. This paper treats a procedure for designing a high precision press with linear hydrostatic bearings.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.769-773
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• 2001

Linear hydrostatic bearings have high stiffness, high damping and excellent guided motion straightness, and thus they are suitable for high precision machine tools. This paper describes the procedure for design and test of a high precision stamping press with vertical hydrostatic bearings. For a hydrostatic bearing set designed and manufactured, measurements were made for the straightness, repeatability and stiffness. They are found to be 1.36$\mu\textrm{m}$/100mm, 0.19$\mu\textrm{m}$/100mm and 1, 261N/$\mu\textrm{m}$ respectively. Based upon the experiences with the hydrostatic bearing, an improved design of the precision press is proposed.

• Tribology and Lubricants
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• v.27 no.2
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• pp.71-76
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• 2011

In this study, the nondimensional load capacity of water hydrodynamic journal bearings is calculated. A generalized coordinate formulation is applied to handle the complexity of bearing geometry. A window-based analysis program is developed to analysis the cylindrical hydrostatic bearings. Load capacities are calculated according to some design parameters such as clearance, diameter of orifice, size of recesses and temperature. The results are presented and discussed.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.05a
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• pp.225-230
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• 2001

Hydrostatic bearings have been applied to high precision machine tools and instruments due to their high stiffness, high damping and excellent guided motion straightness. In this paper, we present a procedure for design and test of a high precision press with linear hydrostatic bearings. For a hydrostatic bearing set designed manufactured, measurements were made for the motion straightness, repeatability and bearing stiffness. They are found to be 1.36${\mu}m$/100mm, 0.19${\mu}m$/100mm and 1,261N/${\mu}m$ respectively. With some experience with the hydrostatic bearing, design aspects of the precision press is discussed.

• The KSFM Journal of Fluid Machinery
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• v.19 no.5
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• pp.35-41
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• 2016

This paper deals with the design, manufacturing and test evaluation of a hydrostatic bearing applied to a hydraulic model turbine. The design parameters of a hydrostatic bearing, considering machining and assembly tolerances, and recommended values of design parameters are presented. Also the simple design procedure of a hydrostatic bearing by utilizing the reference results is proposed. In order to illustrate the utility and validity of the proposed design procedure, two hydrostatic bearings are manufactured and test evaluation of these bearings are performed. In results, the proposed design procedure can be utilized as an effective tool at the initial design screen of a hydrostatic bearing. However, the 2D bearing governing equation should be solved to obtain the optimal design of a hydrostatic bearing.

• Tribology and Lubricants
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• v.33 no.5
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• pp.187-201
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• 2017

This paper presents the impact of couple stress lubricant on performance of slot-entry hydrostatic/hybrid journal symmetric/asymmetric bearings. Reynolds Equation using Finite Element Technique has been solved for the flow of couple stress and Newtonian lubricants in bearings. The results have been computed for concentric design pressure ratio(${\beta}^{\ast}=0.5$), slot width ratio (SWR = 0.25) and chosen parameters of couple stress lubricant ${\bar{l}}=5$, 10, 15. It is observed that numerically simulated outcomes for slot-entry journal bearings, considering the influence of couple stress lubricant indicate a substantial improvement in the performance of the bearing.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.5 s.170
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• pp.159-166
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• 2005

A self-compensated water-hydrostatic bearing is well known to have advantages in stiffness. In this paper, its concept is extended to a hydrostatic journal bearing for achieving higher stiffness. The finite element method is applied to analyze the load characteristics of the self-compensated hydrostatic journal bearing. The analysis results reveal that the self-compensated journal bearing has higher load capacity and higher stiffness than conventional, fixed capillary journal bearings. and that this benefit degrades in the case of high eccentricity. Thus, a spindle system with self-compensated journal bearings must be designed to ensure a sufficiently large load capacity. A rectangular type capillary is also introduced with consideration of the practical application of the self-compensated hydrostatic journal bearing. Theoretical analysis results show that the rectangular type capillary is more beneficial than conventional annular type capillaries in practical use. The experimental verification on the analysis method is made to show that the experimental results are in good agreement with theoretical results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.12 s.255
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• pp.1634-1641
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• 2006

High-precision centerless grinding machines are emerging as a means of finishing the outer diameter grinding process required for ferrules, which are widely used as fiber optic connectors. In this study, a sensitivity analysis for structural and thermal characteristics was carried out using a virtual prototype of a centerless grinding machine to realize systematic design technology and performance improvements required to manufacture ferrules. The prototype consisted of a concrete-filled bed, hydrostatic grinding wheel (GW) and regulating wheel (RW) spindle systems, a hydrostatic RW table feed mechanism, a RW swivel mechanism, and on-machine GW and RW dressers. The results of the structural sensitivity analysis illustrated that the vertical stiffness of hydrostatic guideway for the RW table feed system greatly influenced the horizontal loop stiffness, and the results of the thermal sensitivity analysis illustrated that the heat generation rates at hydrostatic bearings and belt pulley greatly influenced the temperature rise of hydrostatic bearings and the deviation of thermal displacement between GW and RW.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.113-114
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• 2013