Identification of Characteristic Parameters for Hydrostatic Bearings

2015 ◽  
Vol 31 (2) ◽  
pp. 227-240 ◽  
Author(s):  
Y. Kang ◽  
S.-Y. Hu ◽  
Y.-P. Chang ◽  
T.-P. Wang
Keyword(s):  
Flow Rate ◽  
Design Parameters ◽  
Characteristic Parameters ◽  
Measure Flow Rate ◽  
Hydrostatic Bearing ◽  
Supply Pressure ◽  
Hydrostatic Bearings ◽  
Design Values

ABSTRACTThis study proposes a method to identify the characteristic parameters of hydrostatic bearing. When load or supply pressure changed, the inlet and outlet pressures of restrictor, flow rate and worktable displacement are examined for establish identification equations. The practical values of the characteristic parameters can be obtained by minimizing the differences between measure flow rate and identify flow rate. The differences between practical and design values of these parameters can be used to calibrate design parameters for satisfying the requirements.

Static Characteristics of a Rectangular Hydrostatic Thrust Bearing With a Self-Controlled Restrictor Employing a Floating Disk

1993 ◽  
Vol 115 (2) ◽  
pp. 307-311 ◽  
Author(s):  
S. Yoshimoto ◽  
Y. Anno ◽  
M. Fujimura
Keyword(s):  
Flow Rate ◽  
Applied Load ◽  
Thrust Bearing ◽  
Static Characteristics ◽  
Hydrostatic Bearing ◽  
Supply Pressure ◽  
Wide Range ◽  
Bearing Stiffness ◽  
New Type ◽  
Very High

This paper proposes a new type of a self-controlled restrictor which can achieve a very high bearing stiffness in hydrostatic bearings. This self-controlled restrictor employs a floating disk to control the mass flow rate of the oil entering the bearing clearance according to changes of the applied load. Furthermore, a hydrostatic bearing with this restrictor can theoretically achieve an infinite stiffness when the mass of a floating disk is assumed to be zero. The static characteristics of a rectangular hydrostatic thrust bearing with this self-controlled restrictor are theoretically and experimentally investigated. It was consequently shown that the proposed hydrostatic thrust bearing can achieve a very high stiffness (nearly infinite stiffness) in a very wide range of applied load independent of supply pressure.

Investigations in Hydrostatic Planar Bearings Compensated by Tapered-Spool Restrictors I: Flow Rate

2015 ◽  
Vol 32 (1) ◽  
pp. 63-69
Author(s):  
Y. Kang ◽  
H.-C. Cheng ◽  
C.-W. Lee ◽  
S.-Y. Hu
Keyword(s):  
Flow Rate ◽  
Analytical Method ◽  
Pressure Difference ◽  
Load Capacity ◽  
Design Parameters ◽  
Static Characteristics ◽  
Static Stiffness ◽  
Flow Rates ◽  
Single Action ◽  
Hydrostatic Bearing

ABSTRACTThis paper is former part of serial studies to investigate the influence of design parameters of tapered-spool type restrictors on static characteristics of hydrostatic bearing. The flow rates passing restrictors can determine the static characteristics of hydrostatic bearings. In this part an analytical method which includes formulas and solving is utilized to simulate dimensionless flow rate in both single-action and double-action tapered-spool restrictors. The numerical results illustrate the variations of flow rates with respect to the change of pressure and pressure difference, respectively. The findings give that the design parameters of tapered-spool restrictors and the useful range of recess pressure. The following part will depend on this paper results to study load capacity and static stiffness of hydrostatic bearing compensated by tapered-spool restrictor.

Hydrostatic bearings with multiport viscous pumps

2003 ◽  
Vol 217 (4) ◽  
pp. 333-342 ◽  
Author(s):  
H. A. Arafa ◽  
T. A. Osman
Keyword(s):  
Load Carrying Capacity ◽  
Pressure Source ◽  
Hydrostatic Bearing ◽  
Supply Pressure ◽  
Hydrostatic Bearings ◽  
Load Carrying ◽  
Viscous Pump ◽  
Bearing Stiffness ◽  
Flow Pressure ◽  
Good Agreement

An analysis of multirecess hydrostatic bearings with linear flow-pressure supply characteristics is presented. These characteristics can be obtained using either a constant supply pressure source with a laminar flow restrictor before each recess, or, as suggested in this paper, a multiport viscous pump. Analysis of the viscous pump-bearing system is made for odd numbers of recesses, and it is shown that a staggered or skip-one sequence of connection of the pump ports to the bearing recesses gives the least unbalanced reaction between the pump rotor/stator. The flow-pressure characteristics of viscous pumps with peripheral shrouded Rayleigh steps in a cylindrical configuration are derived and used to design a five-port pump to match a hydrostatic bearing. An experimental pump is designed, manufactured and tested, and the results obtained at one port show good agreement with the theoretically calculated values of pressure and flow. If this port is taken as representative of a pump, which is manufactured with higher accuracy, then the principle of having an effective multiport viscous pump is hereby validated. A simple means is suggested for making the bearing stiffness and load-carrying capacity insensitive to temperature/viscosity changes.

Identification of design parameters for spool-type restrictors

2019 ◽  
Vol 234 (1) ◽  
pp. 63-72
Author(s):  
Sheng-Yen Hu ◽  
Yuan Kang ◽  
Hsin-Ming Fu ◽  
Chao-Ping Huang
Keyword(s):  
Flow Rate ◽  
Total Error ◽  
Design Parameters ◽  
Experimental Equipment ◽  
Flow Rates ◽  
Open Type ◽  
Single Action ◽  
Hydrostatic Bearing ◽  
Average Temperature ◽  
Identification Method

This study presents the identification method of design parameters for single-action cylindrical spool-type restrictors of hydrostatic bearing. These parameters include restriction parameter, spool displacement parameter, and spring preload. The flow rates, inlet pressures, and outlet pressures are measured to be utilized for parameter identification of single-action cylindrical spool-type restrictors by using experimental equipment. This equipment-like an open-type planar hydrostatic bearing supports a worktable for changing recess pressure by changing apply load. Then, design parameters can be identified from the measurements of the inlet pressure, the recess pressure, average temperature, and the flow rate for each restrictor by using minimizing total error square between measured and identified quantities of flow rates. An identification method with experiments for single-action cylindrical spool-type restrictors of hydrostatic bearing is presented and designed. Also, the influences of design parameters on flow rate of single-action cylindrical spool-type restrictors are studied by experiments. The experimental equipment used in this study is our design, which can be used for all types of restrictors and hydrostatic bearings. This identification method for design parameters of the single-action cylindrical spool-type restrictors is reliable, valid, and accurate. The identification of design parameters is necessary for design change and calibration of single-action cylindrical spool-type.

scholarly journals Accuracy of Spindle Units with Hydrostatic Bearings

2016 ◽  
Vol 10 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Dmytro Fedorynenko ◽  
Serhii Sapon ◽  
Sergiy Boyko
Keyword(s):  
Radius Vector ◽  
Statistical Characteristics ◽  
Temperature Deformation ◽  
Design Parameters ◽  
Operational Parameters ◽  
Hydrostatic Bearing ◽  
Hydrostatic Bearings ◽  
Spindle Unit ◽  
Shape Errors ◽  
Statistical Regularities

AbstractThe work is devoted to the research of precision regularities in a spindle unit by the trajectory of the spindle installed on hydrostatic bearings. The mathematical model of trajectories spindle with lumped parameters that allows to define the position of the spindle with regard the simultaneous influence of design parameters, geometrical deviations ofform, temperature deformation bearing surfaces, the random nature of operational parameters and technical loads of hydrostatic bearings has been developed. Based on the results of numerical modeling the influence of shape errors of bearing surface of hydrostatic bearing on the statistical characteristics of the radius vector trajectories of the spindle by varying the values rotational speed of the spindle and oil pressure in front hydrostatic bearing has been developed. The obtained statistical regularities of precision spindle unit have been confirmed experimentally. It has been shown that an effective way to increase the precision of spindle units is to regulate the size of the gap in hydrostatic spindle bearings. The new design of an adjustable hydrostatic bearing, which can improve the accuracy of regulation size gap has been proposed.

Review of Research on Hydrostatic Bearings

2020 ◽  
Vol 13 ◽  
Author(s):  
Xiaodong Yu ◽  
Yu Wang ◽  
Junfeng Wang ◽  
Wenkai Zhou ◽  
Hongwei Bi ◽  
...  
Keyword(s):  
High Speed ◽  
Static Pressure ◽  
Development Trend ◽  
Cnc Machining ◽  
Pressure Effects ◽  
Cnc Machine Tools ◽  
Future Research ◽  
Theoretical Formula ◽  
Hydrostatic Bearing ◽  
Hydrostatic Bearings

Background: Hydrostatic bearings have the advantages of strong bearing capacity, good stability, small friction coefficient and long life. The performance of liquid hydrostatic bearings directly affect the accuracy and efficiency of CNC machining equipment. The performance is conducive to the development of CNC machine tools towards high speed and heavy load, so it is necessary to sort out and summarize the existing research results. Objective: This study summarizes the current development status of hydrostatic bearings and explains the development trend of hydrostatic bearings. Methods: According to the recently published journal articles and patents, the recent experimental research on hydrostatic thrust bearings is summarized. This paper summarizes many factors that affect the performance of hydrostatic bearings, and discusses the causes of various factors on hydrostatic bearings. Finally, future research on hydrostatic bearings is presented. Results: The study discusses experimental methods, simulation processes, and experimental results. Conclusion: This study can produce dynamic and static pressure effects by changing the structure of the oil cavity of the hydrostatic bearing. This effect can make up for the static pressure loss. By improving the theoretical formula and mathematical model and proposing a new simulation method, the accuracy of the hydrostatic bearing simulation is satisfied; the future development trend of the hydrostatic bearing is proposed.

Multi-objective optimization of squirrel cage fan for range hood based on Kriging model

2021 ◽  
pp. 095440622199586
Author(s):  
Qianhao Xiao ◽  
Jun Wang ◽  
Boyan Jiang ◽  
Weigang Yang ◽  
Xiaopei Yang
Keyword(s):  
Flow Rate ◽  
Optimization Design ◽  
Volume Flow Rate ◽  
Kriging Model ◽  
Volume Flow ◽  
Design Parameters ◽  
Multi Objective Optimization ◽  
Nsga Ii ◽  
Multi Objective ◽  
Squirrel Cage

In view of the multi-objective optimization design of the squirrel cage fan for the range hood, a blade parameterization method based on the quadratic non-uniform B-spline (NUBS) determined by four control points was proposed to control the outlet angle, chord length and maximum camber of the blade. Morris-Mitchell criteria were used to obtain the optimal Latin hypercube sample based on the evolutionary operation, and different subsets of sample numbers were created to study the influence of sample numbers on the multi-objective optimization results. The Kriging model, which can accurately reflect the response relationship between design variables and optimization objectives, was established. The second-generation Non-dominated Sorting Genetic algorithm (NSGA-II) was used to optimize the volume flow rate at the best efficiency point (BEP) and the maximum volume flow rate point (MVP). The results show that the design parameters corresponding to the optimization results under different sample numbers are not the same, and the fluctuation range of the optimal design parameters is related to the influence of the design parameters on the optimization objectives. Compared with the prototype, the optimized impeller increases the radial velocity of the impeller outlet, reduces the flow loss in the volute, and increases the diffusion capacity, which improves the volume flow rate, and efficiency of the range hood system under multiple working conditions.

Determination of the Discharge Coefficient of a Thin-Walled Orifice Used in Hydrostatic Bearings

2005 ◽  
Vol 127 (3) ◽  
pp. 679-684 ◽  
Author(s):  
S. Charles ◽  
O. Bonneau ◽  
J. Fre^ne
Keyword(s):  
Discharge Coefficient ◽  
Ad Hoc ◽  
Thrust Bearing ◽  
Accurate Estimation ◽  
Hydrostatic Bearing ◽  
Hydrostatic Bearings ◽  
Flow Through ◽  
Thin Walled ◽  
Experimental Bench

The characteristics of hydrostatic bearings can be influenced by the compensating device they use, for example, a thin-walled orifice (diaphragm). The flow through the orifice is given by a law where an ad hoc discharge coefficient appears, and, in order to guarantee the characteristics of the hydrostatic bearing, this coefficient must be calibrated. The aim of this work is to provide an accurate estimation of the discharge coefficient under specific conditions. Therefore an experimental bench was designed and a numerical model was carried out. The results obtained then by the experimental and theoretical approach were compared with the values given by the literature. Finally, the influence of the discharge coefficient on the behavior of a thrust bearing is examined.

Influence of the Variation of Plasma Torch Parameters on Particle Melting and Solidification

1997 ◽  
Author(s):  
M. Vardelle ◽  
P. Fauchais ◽  
A. Vardelle ◽  
A.C. Léger
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Gas Flow ◽  
Operating Conditions ◽  
Characteristic Parameters ◽  
Powder Mass ◽  
Arc Current ◽  
Plasma Sprayed ◽  
Carrier Gas Flow ◽  
Melting And Solidification

Abstract A study of the flattening and cooling of particles plasma-sprayed on a substrate is presented. The characteristic parameters of the splats are linked to the parameters of the impacting particles by using an experimental device consisting of a phase Doppler particle analyzer and a high-speed pyrometer. However, during the long experiments required to get reliable correlations, it was observed that variations in plasma spray operating conditions may alter the particles behavior in the plasma jet. Therefore, a simple and easy-to-use system was developed to control in real time the spray jet. In this paper, the effect of carrier gas flow rate, arc current and powder mass flow rate is investigated. The results on zirconia and alumina powders show the capability of the technique to sense the particle spray position and width.

The Optimum Groove Geometry for Spiral Groove Viscous Pumps

1990 ◽  
Vol 112 (2) ◽  
pp. 409-414 ◽  
Author(s):  
Yuichi Sato ◽  
Kyosuke Ono ◽  
Akihiko Iwama
Keyword(s):  
Differential Equation ◽  
Flow Rate ◽  
Groove Width ◽  
Design Parameters ◽  
Width Ratio ◽  
Maximum Pressure ◽  
Spiral Groove ◽  
Clearance Ratio ◽  
Viscous Pump ◽  
Outflow Rate

The optimum geometries of disk and cylindrical sprial groove viscous pumps to provide the maximum pressure or flow rate are investigated theoretically. The geometrical design parameters, such as the groove angle, groove to ridge clearance ratio, groove width ratio and ridge clearance ratio, are considered as functions of meridional coordinate. Results are obtained from the solution of a differential equation for the smoothed overall pressure distribution of a spiral groove viscous pump. It is found that outflow rate increases with the increase of groove to ridge clearance ratio λ, and that for each value of λ there exist “optimum” values of groove angle and groove width ratio, which give a maximum outflow rate. However, the increase of λ decreases the ridge clearance.

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