Study on oil starvation at the oil seal edge of the oil film of hydrostatic bearing with double rectangular cavity

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shiqian Ni ◽  
Yanqin Zhang ◽  
Zhen Quan
Keyword(s):  
Temperature Rise ◽  
Friction Pair ◽  
Operating Conditions ◽  
Rectangular Cavity ◽  
Lubricating Oil ◽  
Heat Accumulation ◽  
Content Type ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Side Flow

Purpose When the clearance oil film of hydrostatic bearing friction pair is in critical lubrication state, the phenomenon of zero flow of local lubricating oil will aggravate the oil film temperature rise, which needs to be solved. Design/methodology/approach In this paper, the critical lubrication parameter equation and the oil film temperature rise mathematical model are derived for the new type q1-205 double rectangular cavity hydrostatic bearing. Based on a combination of theoretical analysis, simulation and experimental verification, this paper analyzes the flow characteristics and temperature rise characteristics of the lubricating oil when the hydrostatic bearing is in a critical lubrication state under different operating conditions and finally obtains the critical lubrication state of the oil film. Findings This study found that the numerical simulations and the derived formulas agree with the results. When the oil film is in critical lubrication, the cross-section side flow of the oil side is almost zero. The heat cannot be taken away in time, resulting in the local temperature rise of the oil film, which causes serious heat accumulation. Originality/value It is concluded that the operating condition parameters corresponding to the critical lubrication state provide a theoretical basis for the selection of actual hydrostatic bearing operating conditions, which is of great scientific significance.

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.

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.

Pad attitude adjusting moment in large multi-pocket pivoted pad used in static oil journal bearing

2017 ◽  
Vol 69 (4) ◽  
pp. 605-611
Author(s):  
Xizhi Ma ◽  
Miaomiao Li
Keyword(s):  
Flow Rate ◽  
Ball Mill ◽  
Large Scale ◽  
Journal Bearing ◽  
Operating Conditions ◽  
Content Type ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Attitude Adjustment ◽  
Oil Flow

Purpose Large scale is a trend of the ball mill, so the loads on their bearings become very large, bearing operating conditions turn into more severe. The moment of inertia to their pivot of the pad increase significantly, so it leads to the difficult of the pad attitude adjustment and makes the pad tilting angles time response slow, the key factor to effects attitude adjustment is the oil film moment to the pad pivot at unbalance position. the oil film moment and its effect factors must be studied in the design of the bearing used in ball mill. Design/methodology/approach Models about the lubrication of multi-pocket pivoted pad hydrostatic bearing is established, the complicated relationship of the oil flow rate between the oil pockets are taken into account. Finite differential method is used to solv the model, and theroy of finite element method is use to calculate the oil flow rate out of the pocket edges. Newton’s methods are used to determine the pressure of pockets.The pad tilting moment to its pivot is numerically analyzed. Findings The tilting moment to its pivot is set as an indicator of the ability for a pad to adjust its attitude. The effects of the diameter of throttling capillary and the pocket area on the attitude adjusting capacity is studied. Relations between the attitude adjustment capacity for a pad and there effects factors are presented. Practical implications The methods and results have the special reference to the design and operation of multiple pockets tilted pad hydrostatic journal bearing. Originality/value Methods to studied the pad attitude adjustment are given in the article for the multi-pocket pivot pad hydrostatic beairng.The influence factors on pad attitude adjusting capacity are discussed for a this specail kind hydrostatic bearing, the how the factors influence the pad tilting angle adjustment are presented.

Analysis on Influence of Oil Film Thickness on Temperature Field of Heavy Hydrostatic Bearing in Variable Viscosity Condition

2011 ◽  
Vol 239-242 ◽  
pp. 1418-1421 ◽  
Author(s):  
Yan Qin Zhang ◽  
Xiao Qiu Xu ◽  
Xiao Dong Yang ◽  
Hong Mei Li ◽  
Hui Jiang ◽  
...  
Keyword(s):  
Temperature Field ◽  
Film Thickness ◽  
Temperature Rise ◽  
Variable Viscosity ◽  
Lubricating Oil ◽  
Engineering Practice ◽  
Flow State ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Nc Machine

According to the problem of the influence of oil film thickness on temperature rise for heavy hydrostatic thrust bearing during operation， build viscosity-temperature equation of lubricating oil film and mathematics model of oil film temperature rise of heavy hydrostatic bearing with multiple oil pads, simulate the temperature field of hydrostatic bearing with sector cavity under various oil film thickness using FVM(finite volume method), and reveal the influence law of oil film thickness of temperature rise for hydrostatic bearing. The results show that temperature distribution of hydrostatic bearing is much the same under various oil film thicknesses, but the influence of oil film thickness of temperature rise for hydrostatic bearing is greater. The results of numerical calculations actually response flow state inside hydrostatic bearing ，offer theoretical foundation for the design of hydrostatic bearing in engineering practice, and have important significance in improving operation stability of NC machine.

scholarly journals Transient temperature field analysis of variable viscosity RTHSB with a special structural cavity

2020 ◽  
Vol 12 (10) ◽  
pp. 168781402096505
Author(s):  
Jiafu Ruan ◽  
Xigui Wang ◽  
ShuE Ji ◽  
Yongmei Wang ◽  
Siyuan An
Keyword(s):  
Temperature Field ◽  
Film Thickness ◽  
Dynamic Simulation ◽  
Temperature Rise ◽  
Variable Viscosity ◽  
Operating Conditions ◽  
Lubricating Oil ◽  
Transient Temperature ◽  
Oil Film ◽  
Instantaneous Temperature

A radial thrust hydrodynamic sliding bearing (RTHSB) with special shaped cavity had been designed. Taking the instantaneous temperature rise characteristics of RTHSB as an analysis object, considering the influence of inlet lubricating oil velocity and transmission shaft speed, a dynamic simulation method of variable viscosity temperature field is proposed, and the mathematical model of instantaneous temperature rise of time-varying oil film is constructed. The correlation equation between instantaneous temperature rise and oil film variable viscosity is analyzed, the lubricating performance of a special-shaped cavity with variable thickness of the oil film considering real-time full operating conditions is revealed, and the alternating transient laws of oil film thickness with variable viscosity and its instantaneous temperature rise for no-load, heavy-load, and different rotating speeds are studied. It is obtained that the higher temperature area of profiled shaped cavity on reverse flow side extends to oil seal side with increase of rotating speed. The dynamic simulation of variable viscosity of RTHSB with different film thickness is simulated by using FLUENT software and the trend of transient film temperature field distribution of in special-shaped cavity is evaluated. The rationality of the mechanism analysis and numerical simulation results in this paper has been verified.

Influence of structural parameters of friction pair on oil temperature rise in hydro-viscous clutch

2019 ◽  
Vol 72 (1) ◽  
pp. 79-85
Author(s):  
Zhibao Li ◽  
Fangwei Xie ◽  
Junyu Sun ◽  
Jie Zhu ◽  
Xudong Zheng ◽  
...  
Keyword(s):  
Temperature Rise ◽  
Two Phase Flow ◽  
Friction Pair ◽  
Structural Parameters ◽  
Outer Radius ◽  
Phase Flow ◽  
Two Phase ◽  
Content Type ◽  
Oil Film ◽  
Inner Radius

Purpose The purpose of this paper is to study the temperature characteristics of hydro-viscous clutch with different structure of friction disks and obtain the distribution of film temperature. Design/methodology/approach The mathematical model of oil film between friction disks with radial grooves is established. Based on the flow rate equation, the temperature rise equation of oil film is deduced. Considering two-phase flow, the temperature distribution in the oil shear stage and the effects of the ratio of inner radius to outer radius on film temperature rise is studied by using computational fluid dynamics (CFD) technology. Findings The results show that when input speed is constant, the increase in the ratio of inner to outer radius leads to an increase in the peak temperature and the decrease in the ratio results in a larger increasing rate of temperature. Originality/value These results are of interest for the study of hydro-viscous drive and its applications. This study can also provide a theoretical basis for the mechanism of temperature rise by considering the effect of two-phase flow.

Summary of Research on Oil Film Temperature Characteristic of Hydrostatic and Hydrodynamic Thrust Bearings

2021 ◽  
Vol 14 ◽  
Author(s):  
Yanan Feng ◽  
Xiaodong Yu ◽  
Zelin Han ◽  
Shihao Li ◽  
Bangyao Tang ◽  
...  
Keyword(s):  
Temperature Rise ◽  
Thrust Bearing ◽  
Friction Pair ◽  
Dynamic Pressure ◽  
Operational Reliability ◽  
Lubricating Oil ◽  
Research Directions ◽  
Oil Film ◽  
Specific Research ◽  
Thrust Bearings

Background: In order to explore the temperature rise and distribution of the micro-gap lubricating oil film of the hydrostatic and hydrodynamic thrust bearing, further solve the problem of thermal deformation of the friction pair of the hydrostatic and hydrodynamic support and improve the operation accuracy and stability of the hydrostatic and hydrodynamic thrust bearing. Objective: Combined with the theory of dynamic and static pressure bearings, the problem of lubricating oil film temperature rise is analyzed, and specific research directions are proposed. It is hoped that it will be helpful to improve the research of bearing stability and provide a theoretical basis for the structural design and operational reliability of heavy hydrostatic bearings. Methods: This article summarizes the research status of the oil film temperature rise of hydrostatic and hydrodynamic thrust bearings, especially focusing on the influence of hot oil carrying on the temperature rise of the lubricating oil film, and finally the specific research directions and methods of the oil film temperature rise are prospected. Conclusion: Aiming at the research hotspots of lubricating oil film temperature rise and distribution, based on the analysis of the principle of hydrostatic and dynamic pressure bearings, the domestic and foreign literature on the influence of the micro-gap lubricating oil film temperature rise and distribution of hydrostatic and hydrodynamic thrust bearings is collected and analyzed. The research shows that although some research results have been made in this area, due to current research methods and angle analysis still have certain limitations, so the study of the oil film temperature rise is not comprehensive, and further detailed discussion and analysis are still needed.

Thermal elastohydrodynamic lubrication characteristics and optimisation of the ball-type tripod universal joint

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fuqin Yang ◽  
Xiaojie Han ◽  
Mingqing Si
Keyword(s):  
Elastic Modulus ◽  
Film Thickness ◽  
Temperature Rise ◽  
Elastohydrodynamic Lubrication ◽  
Lubricating Oil ◽  
Universal Joint ◽  
Oil Viscosity ◽  
Content Type ◽  
Oil Film ◽  
Lubrication Characteristics

Purpose This paper aims to study the influence of three-column groove shell radius, ball radius, lubricating oil viscosity and elastic modulus on the thermal elastohydrodynamic lubrication (TEHL) characteristics and optimisation of the ball-type tripod universal joint. Design/methodology/approach The point contact TEHL model of the joint was developed, and the multi-grid method was used to solve it. The influence of three-column groove shell radius, ball radius, lubricating oil viscosity and elastic modulus on the lubrication characteristics was analysed. Further, the optimisation of the joint TEHL performance was carried out by the Kriging approximation model combined with the multi-objective particle swarm optimisation (MOPSO) algorithm. Findings The research results show that increasing groove shell radius and ball radius can effectively increase the oil film thickness, and decrease the oil film pressure, as well as the temperature rise. Decreasing elastic modulus can reduce the oil film temperature rise and pressure, and increasing viscosity can effectively increase the oil film thickness. The optimised minimum oil film thickness increases by 33.23% and the optimised maximum oil film pressure and maximum temperature rise decrease by 11.92% and 28.87%, respectively. Furthermore, the relative error of each response output is less than 10%. Originality/value This study applies TEHL theory to the tribological research of the ball-type tripod universal joint, and the joint’s lubrication performance is improved greatly by the Kriging model and MOPSO algorithm, which provides an effective measure to raise the joint’s working efficiency.

Studying Systems of Stabilization of Supports in Hydrostatic Machine Tool

2012 ◽  
Vol 622-623 ◽  
pp. 489-493
Author(s):  
Iskander Beisembetov ◽  
Sabyi Ussupov ◽  
Bakhyt Absadykov ◽  
Beken Arymbekov ◽  
Birzhan Bektibay
Keyword(s):  
Film Thickness ◽  
Machine Tools ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Operational Parameters ◽  
Automatic Stabilization ◽  
Design Elements ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Automatic Control Systems

Development relevance to improve the operational parameters of the support units of machine tools in their design elements is introduced that increase the rigidity of the components, their carrying capacity, damp occurring vibrations in the process, the coefficient of performance (COP), smoothness of motion, positioning accuracy, reducing the wear of their working surfaces and maintain the original accuracy. A number of engineering development [1], [2], aimed at improving the above characteristics of the machine by changing and improving design of reference nodes used in these rails rolling bearings, aerostatic and hydrostatic guides, as well as the use of automatic control systems of its basic parameters, determine its quality. However, in some operating conditions in which errors occur, mainly due to the instability of oil-film thickness (gap) between the mobile and immobile elements of the hydrostatic bearing. For high accuracy requirements it will negatively affect the quality of machined parts and equipment performance. On this basis, it becomes apparent urgency of the problem of automatic stabilization of oil-film thickness (gap) in the IR. To ensure high precision equipment to improve power system hydrostatic bearing units of machine tools. This, in turn, creates the prerequisite for the development of stabilization systems of the gap in the hydrostatic bearing, with the help of which the thickness of oil layer in them would be kept constant even with significant dynamic load on the support.

Dynamic transmission of oil film in soft-start process of HVD considering surface roughness

2018 ◽  
Vol 70 (3) ◽  
pp. 463-473 ◽  
Author(s):  
Fangwei Xie ◽  
Jie Zhu ◽  
Jianzhong Cui ◽  
Xudong Zheng ◽  
Xinjian Guo ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Friction Pair ◽  
Maximum Temperature ◽  
Force Model ◽  
Content Type ◽  
Oil Film ◽  
Soft Start ◽  
Viscous Torque ◽  
Start Process

Purpose The purpose of this paper is to study the dynamic transmission of the oil film in soft start process of hydro-viscous drive (HVD) between the friction pairs with consideration of surface roughness, and obtain the distribution law of temperature, velocity, pressure, shear stress and viscous torque of the oil film. Design/methodology/approach The revised soft-start models of HVD were derived and calculated, including average Reynolds equation, asperity contact model, load force model and total torque model. Meanwhile, a 2D model of the oil film between friction pair was built and solved numerically using computational fluid dynamics (CFD) technique in FLUENT. Findings The results show that the maximum temperature gradually reduces from the intermediate range (z = 0.5 h) to the inner side of the friction pair along the direction of oil film thickness. As the soft-start process continues, pressure gradient along the direction of the oil film thickness gradually changes to zero. In addition, tangential velocity increases and yet radial velocity decreases with the increase of the radius. Originality/value In this paper, it was found that the viscous torque calculated by the numerical method is smaller than that by the CFD model, but their overall trend is almost the same. This also demonstrates the effectiveness of the numerical simulation.

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