Oil film shape prediction of hydrostatic thrust bearing under the condition of high speed and heavy load

2018 ◽  
Vol 70 (7) ◽  
pp. 1243-1250 ◽  
Author(s):  
Xiaodong Yu ◽  
Xu Zuo ◽  
Chao Liu ◽  
Xuhang Zheng ◽  
Hang Qu ◽  
...  
Keyword(s):  
High Speed ◽  
Radial Direction ◽  
Thrust Bearing ◽  
Working Condition ◽  
Cnc Machining ◽  
Heavy Load ◽  
Content Type ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Shape Prediction

Purpose Hydrostatic thrust bearing is a key component of the vertical CNC machining equipment, and often results in friction failure under the working condition of high speed and heavy load. The lubricating oil film becomes thin or breaks because of high speed and heavy load and it affects the high precision and stable operation of the vertical CNC machining equipment; hence, it is an effective way of avoiding friction failure for achieving the oil film shape prediction Design/methodology/approach For the hydrostatic thrust bearing with double rectangular cavities, researchers solve the deformation of the friction pairs in hydrostatic bearing by using the computation of hydrodynamics, elasticity theory, finite element method and fluid-thermal-mechanical coupled method. The deformation includes heat deformation and elasticity deformation, the shape of gap oil film is got according to the deformation of the friction pairs in hydrostatic bearing, and gets the shape of gap oil film, and determines the influencing factors and laws of the oil film shape, and achieves the prediction of oil film shape, and ascertains the mechanism of friction failure. An experimental verification is carried out. Findings Results show that the deformation of the rotational workbench is upturned along its radial direction under the working condition of high speed and heavy load. However, the deformation of the base is downturned along its radial direction and the deformation law of the gap oil film along the radius direction is estimated; the outer diameter is close but the inner diameter is divergent wedge. Originality/value The conclusion can provide a theoretical basis for the oil film control of hydrostatic thrust bearing and improve the stability of vertical CNC machining equipment.

Matching the relationship between rotational speed and load-carrying capacity on high-speed and heavy-load hydrostatic thrust bearing

2018 ◽  
Vol 70 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Xiao-dong Yu ◽  
Lei Geng ◽  
Xiao-jun Zheng ◽  
Zi-xuan Wang ◽  
Xiao-gang Wu
Keyword(s):  
Carrying Capacity ◽  
Rotational Speed ◽  
Thrust Bearing ◽  
Lubricating Oil ◽  
Load Carrying Capacity ◽  
Average Pressure ◽  
Content Type ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Load Carrying

Purpose Rotational speed and load-carrying capacity are two mutual coupling factors which affect high precision and stable operation of a hydrostatic thrust bearing. The purpose of this paper is to study reasonable matching relationship between the rotational speed and the load-carrying capacity. Design/methodology/approach A mathematical model of relationship between the rotational speed and the load-carrying capacity of the hydrostatic bearing with double-rectangle recess is set up on the basis of the tribology theory and the lubrication theory, and the load and rotational speed characteristics of an oil film temperature field and a pressure field in the hydrostatic bearing are analyzed, reasonable matching relationship between the rotational speed and the load-carrying capacity is deduced and a verification experiment is conducted. Findings By increasing the rotational speed, the oil film temperature increases, the average pressure decreases and the load-carrying capacity decreases. By increasing the load-carrying capacity, the oil film temperature and the average pressure increases and the rotational speed decreases; corresponding certain reasonable matching values are available. Originality/value The load-carrying capacity can be increased and the rotational speed improved by means of reducing the friction area of the oil recess by using low-viscosity lubricating oil and adding more oil film clearance; but, the stiffness of the hydrostatic bearing decreases.

Influence of recess shape on comprehensive lubrication performance of high speed and heavy load hydrostatic thrust bearing

2019 ◽  
Vol 71 (2) ◽  
pp. 301-308
Author(s):  
Mubing Yu ◽  
Xiaodong Yu ◽  
Xuhang Zheng ◽  
Hang Qu ◽  
Tengfei Yuan ◽  
...  
Keyword(s):  
High Speed ◽  
Thrust Bearing ◽  
Great Influence ◽  
Constant Flow ◽  
Heavy Load ◽  
Content Type ◽  
Lubrication Performance ◽  
Improved Performance ◽  
Volume Method ◽  
Selection Of

Purpose This paper aims to describe a theoretical and experimental research concerning influence of recess shape on comprehensive lubrication performance of high speed and heavy load hydrostatic thrust bearing with a constant flow. Design/methodology/approach The lubrication performance of a hydrostatic thrust bearing with different recess shape under the working conditions of high speed and heavy load has been simulated by using computational fluid dynamics and finite volume method. Findings It is found that the comprehensive lubrication performance of a hydrostatic thrust bearing with circular recess is optimal. The results demonstrate that recess shape has a great influence on the lubrication performance of the hydrostatic thrust bearing. Originality/value The simulation results indicate that to get an improved performance from a hydrostatic thrust bearing with constant flow, a proper selection of the recess shape is essential.

Hot oil carrying characteristic about hydrostatic bearing oil film of heavy vertical lathe in high speed

2019 ◽  
Vol 71 (1) ◽  
pp. 126-132
Author(s):  
Yanqin Zhang ◽  
Pengrui Kong ◽  
Yanan Feng ◽  
Lili Guo
Keyword(s):  
High Speed ◽  
Variable Viscosity ◽  
Load Condition ◽  
Cnc Machine Tools ◽  
Engineering Practice ◽  
Cnc Machine ◽  
Content Type ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Volume Method

Purpose To investigate the effects of hot oil carrying (HOC), the purpose of this paper is to present a new calculation method of oil film temperature which takes the effects into account and defines the factor of HOC. Design/methodology/approach Based on finite volume method, the paper studied the temperature characteristics in high speed and the condition of variable viscosity from the temperature field and flow field of the film, and the thermal rule of HOC is revealed. The theoretical values are in good agreement with the experimental results. Findings The results show that, for this structure of hydrostatic bearing, the phenomenon of HOC does not occur until the work speed is more than 10 r/min under any load condition. And it always happens in the total range of load, from 0 to 320 kN, when the speed is over 60 r/min. Moreover, the film temperature increases sharply, when the phenomenon happens in high speed, and the influence of the speed is greater than the effect of load on the temperature rise. Originality/value The results would help to increase the speed of CNC machine tools and the design on structure of the bearing in engineering practice.

Thermal-fluid-solid coupling deformation of hydrostatic thrust bearing friction pairs

2019 ◽  
Vol 71 (3) ◽  
pp. 467-473 ◽  
Author(s):  
Mubing Yu ◽  
Xiaodong Yu ◽  
Xuhang Zheng ◽  
Hui Jiang
Keyword(s):  
Failure Mechanism ◽  
Rotational Speed ◽  
High Speed ◽  
Thrust Bearing ◽  
Lubricating Oil ◽  
Oil Viscosity ◽  
Heavy Load ◽  
Content Type ◽  
Coupling Deformation ◽  
Bearing Friction

Purpose The purpose of this paper is to study thermal-fluid-solid coupling deformation and friction failure mechanism of bearing friction pairs under the working conditions of high speed and heavy load. Design/methodology/approach The deformation is simulated based on thermal-fluid-solid coupling method, its deformation distribution law is revealed and the relationships of deformation of friction pairs, rotational speed and bearing weight are obtained. Findings The results prove that the oil film temperature rises sharply, the lubricating oil viscosity decreases rapidly, the film thickness becomes thinner, the deformation increases, the whole deformation is uneven and the boundary lubrication or dry friction are caused with the increase in rotational speed and bearing load. Originality/value The conclusions provide theoretical method for deformation solution and friction failure mechanism of hydrostatic thrust bearing.

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.

Effect of recess depth on lubrication performance of annular recess hydrostatic thrust bearing by constant rate flow

2018 ◽  
Vol 70 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Jun-peng Shao ◽  
Guang-dong Liu ◽  
Xiao-dong Yu ◽  
Yan-qin Zhang ◽  
Xiu-li Meng ◽  
...  
Keyword(s):  
Thrust Bearing ◽  
Simulation Method ◽  
Content Type ◽  
Oil Film ◽  
Constant Rate ◽  
Lubrication Performance ◽  
Optimal Value ◽  
Improved Performance ◽  
Lubrication Characteristics ◽  
Volume Method

Purpose The purpose of this paper is to describe a simulation and experimental research concerning the effect of recess depth on the lubrication performance of a hydrostatic thrust bearing by constant rate flow. Design/methodology/approach The computational fluid dynamics and finite volume method have been used to compute the lubrication characteristics of an annular recess hydrostatic thrust bearing with different recess depths. The performances are oil recess pressure, oil recess temperature and oil film velocity. The recess depth has been optimized. A test rig is established for testing the pressure field of the structure of hydrostatic thrust bearing after recess depth optimization, and experimental results show that experimental data are basically identical with the simulation results, which demonstrates the validity of the proposed numerical simulation method. Findings The results demonstrate that the oil film temperature decreases and the oil film pressure first increases and then decreases with an increase in the recess depth, but oil film velocity is constant. To sum up comprehensive lubrication performance, the recess depth of 3.5 mm is its optimal value for the annular recess hydrostatic thrust bearing. Originality/value The computed results indicate that to get an improved performance from a constant flow hydrostatic thrust bearing, a proper selection of the recess depth is essential.

Multi-Objective Topological Optimization of Support Frame for High-Speed and Heavy-Load Triangle Track Wheel Based on Analytic Hierarchy Process

2018 ◽  
Author(s):  
Fenghe Wu ◽  
Zhaohua Wang ◽  
Yinxu Sun ◽  
Yulin Yang ◽  
Yongxin Li ◽  
...  
Keyword(s):  
Topology Optimization ◽  
High Speed ◽  
Working Condition ◽  
Average Frequency ◽  
Frequency Method ◽  
Analytic Hierarchy ◽  
Heavy Load ◽  
Multi Objective ◽  
Support Frame ◽  
Hierarchy Process

The high-speed, heavy-load and changeable triangle track wheel is a motion device that can carry out interchange between the track wheel and tire in an ordinary vehicle. The topology optimization for the support frame can reduce weight and improve the maneuverability of the vehicle. However, it is difficult to consider simultaneously its weight, stiffness and modal in the process of the structure optimization. Thus, a topology optimization method for multi-objective and multi-working-condition is proposed based on the AHP (analytic hierarchy process) and average frequency method. Firstly, considering the static multi-stiffness target and dynamic vibration frequency target, using the compromise programming method and average frequency method, the objective function of the multi-objective and multi-working-condition topology optimization is established. Then, based on the optimization target, design criteria and indexes, the lightweight hierarchical structure model of the support frame consisting of three levels and eight weight factors is established. Values of 8 weight coefficients of the multi-objective topology optimization are determined through solving the weight factor judgment matrix. Finally, considering the multi-working-condition, taking the minimum objective function of the static and dynamic characteristics as target, and the volume ratio is 50% as boundary, the mathematical model of the topology optimization is established. Simulation results show that the stiffness and strength of the support frame are improved respectively by 74.3% and 1.3% while its weight is reduced by 16.3%. This method also provides a new way to the lightweight design for other large, heavy and multi-condition equipment.

On the performance of foil thrust bearing with misaligned bearing runner

2017 ◽  
Vol 69 (2) ◽  
pp. 105-115 ◽  
Author(s):  
Abdelrasoul M. Gad
Keyword(s):  
High Speed ◽  
Thrust Bearing ◽  
Approximation Technique ◽  
Hydrodynamic Effect ◽  
Stable Operation ◽  
Content Type ◽  
Thrust Bearings ◽  
Load Carrying ◽  
Foil Thrust Bearing ◽  
Stiffness And Damping

Purpose Compliant foil thrust bearings are promising bearings for high-speed oil-free turbomachinery. However, most previous experimental and numerical approaches to investigate the performance of these bearings have ignored the effect of bearing runner misalignment. Therefore, this paper aims to evaluate the effects of static and dynamic angular misalignments of the bearing runner on the performance of a gas-lubricated foil thrust bearing. Design/methodology/approach The bearing runner is allowed a maximum angular misalignment that produces a minimum gas film thickness as low as 20 per cent of the nominal clearance. Then, the variations of bearing load carrying capacity, viscous power loss and stiffness and damping coefficients of the gas film with runner misalignment are thoroughly analyzed. The flow in the gas film is modeled with compressible Reynolds equation along with the Couette approximation technique, and the deformation of the compliant bearing is calculated with a robust analytical model. Small perturbations method is used to calculate the force and moment dynamic coefficients of the gas film. Findings The results show that misaligned foil thrust bearings are capable of developing a restoring moment sufficient enough to withstand the imposed misalignments. Furthermore, the enhanced hydrodynamic effect ensures a stable operation of the misaligned bearing, and the results highlighted the role of the compliant bearing structure to maintain foil bearing prominent features even at misaligned conditions. Originality/value The value of this study is the evaluation of the effects of runner angular misalignments on the static and dynamic characteristics of Generation II bump-type foil thrust bearing.

Application of dynamic mesh technology in the oil film flow simulation for hydrostatic bearing

2019 ◽  
Vol 71 (1) ◽  
pp. 146-153
Author(s):  
Yanqin Zhang ◽  
Zhiquan Zhang ◽  
Xiangbin Kong ◽  
Rui Li ◽  
Hui Jiang
Keyword(s):  
Film Thickness ◽  
Flow Velocity ◽  
Manufacturing Industry ◽  
Dynamic Mesh ◽  
Lubricating Oil ◽  
Thickness Variation ◽  
Content Type ◽  
Oil Film ◽  
Rotating Speed ◽  
Hydrostatic Bearing

Purpose The purpose of this paper was to obtain the lubrication characteristics of heavy hydrostatic bearing in heavy equipment manufacturing industry through theoretical analysis and numerical simulation. Design/methodology/approach This paper discusses the influence of oil film thickness variation on velocity field, outlet-L and outlet-R flow velocity under the hydrostatic bearing running in no-load 0 N, load 400 KN, full load 1,500 KN and rotating speeds of 10 r/min, 20 r/min, 30 r/min, 40 r/min, 50 r/min and 60 r/min, by using dynamic mesh technology and FLUENT software. Findings When the working table rotates clockwise, in the change process of oil film thickness, the fluid flow pattern of the lubricating oil at the edge of the sealing oil is the rule of laminar flow, and the oil cavity has a vortex. The outlet-R flow velocity becomes higher and higher by increasing the bearing load and working table speed, and the flow velocity increases with the decrease in oil film thickness; the outlet-L flow velocity increases with the decrease in oil film thickness under low rotating speed (less than 10 r/min) condition and decreases with the decrease of oil film thickness under high rotating speed (more than 60 r/min) condition. Originality/value The influence of the oil film thickness on the flow state distribution of the oil film was analyzed under different working conditions, and the influence rules of oil film thickness on the flow velocity of hydrostatic bearing oil pad was obtained by using dynamic mesh technology.

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