scholarly journals Numerical Simulation and Experimental Study of the Hydrostatic Spindle with Orifice Restrictors

2016 ◽  
Vol 10 (1) ◽  
pp. 79-92
Author(s):  
He Qiang ◽  
Li Lili ◽  
Ren Fengzhang ◽  
Volinsky Alex
Keyword(s):  
Thrust Bearing ◽  
Rotation Speed ◽  
Cold Drawing ◽  
Rolling Bearings ◽  
Element Analysis ◽  
Rotating Speed ◽  
Hydrostatic Bearing ◽  
Fluid Flow Velocity ◽  
Hydrostatic Bearings ◽  
The Finite Element Analysis

Based on the theory of hydrostatic bearings, this paper presents a study of replacing the rolling bearings in a cold drawing spindle with the liquid hydrostatic bearings. An unloading mechanism is designed, containing two hydrostatic radial bearings and a thrust bearing, according to the mechanical characteristics of the spindle. In this study, a mathematical model of the hydrostatic bearing oil pad is developed. The effects of the rotating speed on pressure and flow fields of the oil pad are simulated using the finite element analysis and verified experimentally. The pressure in all recesses decreases with the rotation speed. Oil velocity of the radial hydrostatic bearing recess increases with the rotation speed, while the fluid flow velocity has almost no correlation with the rotation speed of the thrust bearing. The numerical and experimental results of the pressure in the recesses are consistent, confirming the validity and feasibility of this design.

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.

Calculation and Simulation Azimuth Hydrostatic Thrust Bearing of a Large Alt-Azimuth Telescope

2013 ◽  
Vol 364 ◽  
pp. 28-32
Author(s):  
Long Huang ◽  
Wen Li Ma ◽  
Jin Long Huang
Keyword(s):  
Thrust Bearing ◽  
Structure Parameter ◽  
Tracking Accuracy ◽  
Low Friction ◽  
Element Analysis ◽  
Hydrostatic Bearing ◽  
Wide Range ◽  
And Performance ◽  
Large Telescopes ◽  
Main Factor

The use of hydrostatic bearing for support of telescope offers a number of potential performance advantages, but the structure parameter of bearing is the main factor which influence the bearing. The temperature rise of bearing is also important for the stiffnees of the telescope mount.In addition to the known benefit of mount stiffness and tracking accuracy from exceedingly low friction, the hydrostatic bearing provides a wide range of geometric possibilities for large telescopes [1].This paper analyzes various familiar hydrostatic bearing for the azimuth and elevation axes of telescope.Theoretical calculation and simulation show that the performance of bearing meets telescope’s design requirements.The principle and process of this work and Finite Element Analysis (FEA) are introduced in detail. According to the CFX result, the structure parameter and performance of bearing ,temperature field and pressure distribution have obtained.

Simulation on Multi-Oil-Cavity and Multi-Oil-Pad Hydrostatic Bearings

2013 ◽  
Vol 274 ◽  
pp. 274-277 ◽  
Author(s):  
Xiao Qiu Xu ◽  
Jun Peng Shao ◽  
Xiao Dong Yang ◽  
Yan Qin Zhang ◽  
Xiao Dong Yu ◽  
...  
Keyword(s):  
Hydraulic System ◽  
Thrust Bearing ◽  
Three Dimensional ◽  
Structure Design ◽  
Analysis Software ◽  
Hydrostatic Bearing ◽  
Hydrostatic Bearings ◽  
Simulation Results ◽  
Three Dimensional Models ◽  
Volume Method

Taking multi-oil-cavity and multi-oil-pad hydrostatic bearings as studied projects, firstly make brief instructions for structure characteristics and working principal of hydraulic system; Then, build three-dimensional models of multi-oil-cavity and multi-oil-pad hydrostatic bearings respectively. Adopting finite volume method, oil film mesh is generated by universal finite analysis software CFD; then, carry on numerical simulations for pressure distribution and temperature distribution of the two studied hydrostatic thrust bearing under various viscosity, and make comparative analysis for difference between the two studied hydrostatic thrust bearing. Based on the analysis of numerical simulation results, the conclusions whether oil-return groove is set for hydrostatic bearing could be received. Simulation results reveal truly the influence of setting oil-return groove or not on hydrostatic thrust bearing, and improve structure design for hydrostatic thrust bearing.

Research About Eddy Effect and Dynamic Force of the Magnetic Thrust Bearing

2014 ◽  
Author(s):  
Xingnan Liu ◽  
Ni Mo ◽  
Guojun Yang ◽  
Zhengang Shi ◽  
Suyuan Yu
Keyword(s):  
Thrust Bearing ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Dynamic Force ◽  
Phase Lag ◽  
Direct Part ◽  
Element Analysis ◽  
Large Eddy ◽  
The Finite Element Analysis ◽  
Sinusoidal Current

The eddy effect of the magnetic thrust bearing (MTB) is researched by the finite element analysis (FEA). The active magnetic bearing (AMB) is an advanced bearing, used in HTR-PM. The alternating current in the bearing windings will decrease the electromagnetic force and cause phase lag, especially in the MTB which has no lamination structure. According to the calculation in this paper, simple sinusoidal current has large eddy effect. The force decreases obviously and the phase lag is large. However, the current containing direct part and sinusoidal part, which is closer to actual current, has less eddy effect. That is to say, because of the direct part in the current, the eddy effect of the sinusoidal part decreases.

Hydrodynamic Analysis of Hydrostatic Bearings With Runner Misalignment and Pad Damage

2013 ◽  
Author(s):  
Timothy Dimond ◽  
David Barnes
Keyword(s):  
Film Thickness ◽  
Analytical Solutions ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Element Solution ◽  
Flow Loop ◽  
Hydrodynamic Analysis ◽  
Hydrostatic Bearing ◽  
Hydrostatic Bearings ◽  
Minimum Film Thickness

Hydrostatic bearings are used in applications where surface speeds are low, or viscosities are insufficient to develop significant load capacity due to shear flow. They are also used in jacking applications for initial liftoff of rotors under low or no rotation conditions, especially for heavy rotors where significant babbitt damage would otherwise occur. Traditional hydrostatic bearing analyses assume isothermal lubricating flows. Analytical solutions also assume that the pressure in the pocket of the hydrostatic bearing is constant. This assumption is only approximately correct for low and zero operating speeds. Analytical solutions also assume that the runner and pad surfaces are parallel. The analytical solutions are not capable of capturing damage or misalignment effects. This paper describes a hydrodynamic analysis of a hydrostatic thrust bearing. The solution is based on a finite element solution to the generalized Reynolds equation. The finite element solution is applied in both the pocket and pad regions of the hydrostatic bearings. The analysis includes a flow loop balance that considers the effects of pressure losses in the lubricant supply piping, allowing for modeling of saturation effects in bearing load capacity. The flow loop balance for the lubrication supply is coupled with the bearing solution. This allows for pad loads to vary as a function of circumferential position in thrust bearings. The analysis was applied to the operation of a hydrostatic thrust bearing system for the HUSIR radio telescope at the Massachusetts Institute of Technology. Simplified models of pad damage and runner misalignment were considered in the analysis. The minimum film thickness and pressure profile was calculated. Runner misalignment reduced minimum film thickness by up to 80% when compared to a parallel runner under identical loading conditions. Runner damage equivalent to twice the nominal film thickness reduced the minimum film thickness by approximately 10%.

RESEARCH ON PERFORMANCE OF DIAMOND BLADE IN DICING SAW BASED ON ANSYS METHOD

2012 ◽  
Vol 11 (02) ◽  
pp. 125-133
Author(s):  
YAN MA
Keyword(s):  
Tangential Stress ◽  
Equivalent Stress ◽  
Mechanical Analysis ◽  
Maximum Tangential Stress ◽  
Grinding Wheel ◽  
Analysis Software ◽  
Element Analysis ◽  
Rotating Speed ◽  
Diamond Blade ◽  
The Finite Element Analysis

Mechanical analysis is performed on the diamond blade in the dicing saw, and the tangential and radial stresses are presented. The maximum tangential stress and the critical rotating speed to the destructive moment of the grinding wheel are determined. With the finite element analysis software ANSYS, the model of grinding wheel diamond blade is studied and the equivalent stress nephogram with different speeds is presented. The simulation results demonstrate that the tangential stress is larger than the radial stress and that the maximum tangential stress happens on the inner surface. Moreover, the movement trend of curve of the maximum tangential stress nearly corresponds to the theoretical curve.

The Design and Analysis of Novel Carbon-Free Vacuum Cleaner

2014 ◽  
Vol 644-650 ◽  
pp. 602-605
Author(s):  
Jian Xin Zhang ◽  
Zhang E Zhang ◽  
Qiang Zhang
Keyword(s):  
Rotation Speed ◽  
Gear Up ◽  
Concept Design ◽  
Analysis Method ◽  
Vacuum Cleaner ◽  
Element Analysis ◽  
Finite Element Analysis Method ◽  
The Finite Element Analysis ◽  
External Forces ◽  
The Ideal

We propose a new concept design about carbon-free vacuum cleaner. The carbon-free vacuum cleaner moves under the act of external forces instead of the motor, and transmits the rotation speed from low to the ideal speed with the gear up box. In order to to verify the reasonableness of the gear up mechanism and weather the designing of the gears meet the demand, we construct the detail assemble model of the gear up mechanism based on pro/e software, and then analyze the gear with the finite element analysis method.

Simulation on Supporting Characteristics of Heavy Hydrostatic Thrust Bearing

2012 ◽  
Vol 157-158 ◽  
pp. 94-97 ◽  
Author(s):  
Yan Qin Zhang ◽  
Rui Li ◽  
Chun Xi Dai ◽  
Jun Peng Shao ◽  
Xiao Dong Yu ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Thrust Bearing ◽  
Pressure Field ◽  
Internal Flow ◽  
Engineering Practice ◽  
Rotating Speed ◽  
Hydrostatic Bearing ◽  
Cavity Structure ◽  
Volume Method

The pressure field of the clearance oil film of the hydrostatic bearing in varies velocities was simulated based on Finite Volume Method (FVM) by the software of Computational Fluid Dynamics. In this article, a conclusion could be drawn that the viscosity has great influences on the pressure in the heavy hydrostatic bearing and it cannot be neglected especially in high rotating speed. The results of numerical calculations provide internal flow status inside the bearing, which would help the design of the oil cavity structure of the bearing in engineering practice.

scholarly journals Study on the JH-2 Model Parameters for Metro Shield Cutting Reinforced Concrete Pile

2021 ◽  
Author(s):  
Ping Xu ◽  
Sixian Zuo
Keyword(s):  
Constitutive Model ◽  
Rotation Speed ◽  
Three Dimensional ◽  
Adaptive Mesh ◽  
Model Parameters ◽  
Element Analysis ◽  
Concrete Pile ◽  
Key Points ◽  
The Finite Element Analysis ◽  
Shield Machine

Abstract In order to investigate the application of JH-2 (Johnson-Holmquist-2) constitutive model in concrete, a series of parameters study have been conducted to evaluate the JH-2 model in C30 concrete. The finite element analysis software ABAQUS is utilized to simulate the compression test of the three-dimensional standard concrete test based on the ALE adaptive mesh and the damage failure criterion of element deletion function. The numerical analysis of 3D concrete pile foundation and simplified shield machine cutterhead to simulate shield cutting pile is established. Analyzing the numerical simulation and construction data, the key points of the shield machine cutting pile are illustrated. Research shows that: (1) JH-2 constitutive model can be used to simulate the concrete cutting. (2) The better damage parameters have been represented and verified against the results of experiments, which are the D1 = 0.6 and D2 = 0.1 in the JH-2 model of C30 concrete. (3) In the simulation example of concrete compression and cutting pile, the failure form of concrete is brittle failure, and the non-linear characteristics of concrete has been observed. (4) The simulated torque vibration of the cutterhead is relatively large than actual pile cutting, and the actual shield machine cutting pile construction should have a low rotation speed and low propulsion speed.

A Finite Element Analysis on Metal Ball Effect on Dynamics of a Ball Bearing

2018 ◽  
Vol 875 ◽  
pp. 100-104
Author(s):  
Bo Wun Huang ◽  
Jia Sheng Chen ◽  
Zhi Yin Huang ◽  
Nan Wen Lin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Characteristic ◽  
High Performance ◽  
Ball Bearing ◽  
Dynamic Properties ◽  
Element Model ◽  
Element Analysis ◽  
Rotating Speed ◽  
The Finite Element Analysis

The bearings are widely used in the rotating machinery systems to support the mechanical, structural for system. In a high rotating speed, the spindle to be stable rotating is dependent on a high performance bearing. Therefore, the dynamic characteristic of a ball bearing is very importance and need to study. In this work, the dynamic characteristic of a ball bearing is focused to study. Because the geometric of ball bearing are so complex, the finite element analysis is employed to investigate. By using the finite element analysis software ANSYS, the bearings meshed model can be setup. The dynamic properties, natural frequency and mode shape of ball and global system, can be studied to improve the high spindle rotating stable performance. Numerical indicates that the stress, strain and dynamics of the ball bearing system can be investigated in this finite element model.

Sign in / Sign up

Export Citation Format

Share Document