Oil film boundary analysis of spiral oil wedge sleeve bearing based on the dynamic loading conditions

2016 ◽  
Vol 231 (2) ◽  
pp. 254-262 ◽  
Author(s):  
Li-li Wang ◽  
Min Wang ◽  
Xiao-dong Hu ◽  
Chun-jian Su
Keyword(s):  
Dynamic Loading ◽  
Carrying Capacity ◽  
Reynolds Equation ◽  
Inertia Force ◽  
Sleeve Bearing ◽  
Oil Film ◽  
Lubrication Equation ◽  
Film Boundary ◽  
Dynamic Loading Conditions ◽  
Generalized Reynolds Equation

The area and location of cavitation change with time in the condition of dynamic loading. The cavitation location of sleeve bearing not only depends on axis location and velocity at a certain moment but also is affected by cavitation history, so the boundary condition need to be defined in the solution of lubrication equation. Based on the balance of axial inertia force, oil film force, and dynamic loading, the motion equation, generalized Reynolds equation and oil film thickness equation of spiral oil wedge sleeve bearing are established. The results show that the cavitation location and carrying capacity vary periodically with the change in time. The effect of dynamic loading and rotational speed on the oil film cavitation and carrying capacity is studied.

Behavior of Finite Journal Bearings Under Dynamic Loading Conditions

1980 ◽  
Vol 102 (3) ◽  
pp. 333-338 ◽  
Author(s):  
G. S. A. Shawki ◽  
M. O. A. Mokhtar ◽  
Z. S. Safar
Keyword(s):  
Boundary Conditions ◽  
Computer Program ◽  
Variational Methods ◽  
Axial Length ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
The Third ◽  
Dynamic Loading Conditions ◽  
Generalized Reynolds Equation

Performance characteristics for a complete journal bearing of finite axial length are obtained analytically using a new set of boundary conditions. The generalized Reynolds equation is transformed, in the present analysis, into three ordinary differential equations, two of which being readily integrable while the third is solved by variational methods. By the aid of a specially devised computer program, the validity of the analysis has been assured when applied to prescribed journal loci including stationary, circular, elliptical, and linear harmonic journal oscillation.

Study on the Oil Film Static Performance of Sliding Bearings with Different Throttling Methods

2012 ◽  
Vol 155-156 ◽  
pp. 519-525
Author(s):  
Da Ying Li ◽  
Gui Yun Jiang
Keyword(s):  
Carrying Capacity ◽  
Continuity Equation ◽  
Reynolds Equation ◽  
Vital Role ◽  
Static Characteristics ◽  
Sliding Bearings ◽  
Oil Film ◽  
Numerical Solution Methods ◽  
Solution Methods ◽  
Static Performance

The restrictors of fluid lubricated sliding bearings play vital role in oil film rigidity and carrying capacity of bearings. The mathematical models for solution of the oil film static performance of the bearings with four different restrictors were presented and the numerical solution methods were analyzed. The solutions for oil film static characteristics in many aspects such as discretization of Reynolds equation, building clearance function, determinating boundary conditions, constructing continuity equation, deducing the models of oil inlet flow, solving the carrying capacity were conducted. The computational results show that the bearings with capillary or orifice restrictor have lower carrying capacity and oil film rigidity than those with sliding valve feedback or film feedback restrictors.

A numerical analysis and experimental investigation of three oil grooves sleeve bearing performance

2019 ◽  
Vol 71 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Lili Wang ◽  
Qingliang Zeng ◽  
Changhou Lu ◽  
Peng Liang
Keyword(s):  
Navier Stokes ◽  
Phase Flow ◽  
Two Phase ◽  
Content Type ◽  
Sleeve Bearing ◽  
Oil Film ◽  
Rotating Speed ◽  
Film Boundary ◽  
Input Pressure ◽  
Change Trend

Purpose This paper aims to reveal the cavitation characteristics of three oil wedges sleeve bearing and set the theoretical and experimental basis for defining the oil film boundary condition. Design/methodology/approach Computational fluid dynamics model of three oil wedges sleeve bearings based on the Navier–Stokes equation is set using Fluent considering turbulent situation and two-phase flow theory. The cavitation characteristics of bearing is investigated by taking pictures of experiment. Findings The rupture region of oil film and the contours of air volume fraction increase distinctly with the increase of rotating speed and the decrease of input pressure. The critical rotating speed of cavitation occurrence and oil film pressure increases with the increase of input pressure. The change trend of experiment cavitation with the rotating speed and input pressure is consistent with theoretical cavitation in general. Originality/value The finite element model of three oil wedges sleeve bearings is established based on the Navier-Stokes calculation equation of the fluid, two-phase flow theory and turbulent model. Sleeve bearing is transparent, the pictures of cavitation can be easily taken by high-speed camera, the cavitation characteristics of bearing is studied by experiment. The cavitation performance of three oil wedges bearings is studied with the change of input pressure and rotating speed, the change trend is basically consistent for theory and experiment. The study on critical rotating speed of cavitation occurrence is benefit for defining the oil film boundary condition.

Study on Throttle Methods for Hydrostatic Bearing

2013 ◽  
Vol 373-375 ◽  
pp. 2119-2123
Author(s):  
Gui Yun Jiang ◽  
Yong Qin Wang ◽  
Xin Chun Yan
Keyword(s):  
Mathematical Models ◽  
Carrying Capacity ◽  
Applied Load ◽  
Reynolds Equation ◽  
Slide Valve ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Pressure Fields ◽  
Hydrostatic Bearings ◽  
Compensatory Effect

In hydrostatic bearing, the applied load is carried through the compensatory effect of restrictors. Different throttle methods will bring different oil film rigidity and carrying capacity. There are mainly four types restrictors such as capillary,orifice,slide valve and film feedback restrictors. The mathematical models of carrying capacity and oil film rigidity of the hydrostatic bearings throttled by the restrictors mentioned above were presented. The oil film rigidity of hydrostatic bearings throttled by different restrictors were analyzed. Reynolds equation was provided and the numerical solution model was constructed. The pressure fields show the static performances of hydrostatic bearing with different restrictors.

On the Influence of Thrust Bearings on the Nonlinear Rotor Vibrations of Turbochargers

2016 ◽  
Author(s):  
Ioannis Chatzisavvas ◽  
Aydin Boyaci ◽  
Andreas Lehn ◽  
Marcel Mahner ◽  
Bernhard Schweizer ◽  
...  
Keyword(s):  
Hydrodynamic Model ◽  
Reynolds Equation ◽  
Energy Equation ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Oil Viscosity ◽  
Oil Film ◽  
Thrust Bearings ◽  
Run Up ◽  
Generalized Reynolds Equation

This work investigates the influence of hydrodynamic thrust bearings on the lateral rotor oscillations. Four thrust bearing models are compared in terms of their predictions of the oil-film pressure (Reynolds equation), the oil-film temperature (energy equation) and the load capacity. A detailed thrust bearing model using the generalized Reynolds equation and the 3D energy equation, a model using the standard Reynolds equation with a 2D energy equation, a model where the standard Reynolds equation and the 2D energy equation are decoupled and finally an isothermal thrust bearing model are presented. It is shown that in lower rotational speeds, the four models produce almost the same results. However, as the rotational speed is increased, the necessity for a thermo-hydrodynamic model is demonstrated. Run-up simulations of a turbocharger rotor/bearing system are performed, using an isothermal thrust bearing model with different inlet oil-temperatures. The influence of the oil-temperature of the thrust bearing on the subsynchronous rotor oscillations is investigated. Finally, a thermo-hydrodynamic model is compared with an isothermal in run-up simulations, where the influence of the variable oil-viscosity is discussed.

Study on Water Cushion Belt Conveyor

2014 ◽  
Vol 1016 ◽  
pp. 14-18
Author(s):  
Xian Wei Liu ◽  
Jia Sheng Wang ◽  
Lan Tao Wu ◽  
Xin Zhang ◽  
Hua Cheng
Keyword(s):  
Reynolds Equation ◽  
Belt Conveyor ◽  
Working Mechanism ◽  
Film Properties ◽  
Practical Applications ◽  
Lubrication Equation ◽  
Start Up ◽  
New Type ◽  
Air Cushion ◽  
Lubricating Mechanism

Based on air cushion belt conveyor, a new type of belt conveyor named water cushion belt conveyor is proposed. It has a wide scope of applications for its features such as stability and reliability, capability of full load start-up, and environment-friendliness. This paper studies the working mechanism and lubricating mechanism of the water cushion belt conveyor. The basic lubrication equation of the water cushion is deduced from the universal form of the Reynolds equation used to study the pressure film properties of the water cushion. The design of the key part of the water cushion device is described in details. The research can be taken as a reference in practical applications.

Development and Verification of a Dynamic TKR Model

2002 ◽  
Author(s):  
Jason P. Halloran ◽  
Anthony J. Petrella ◽  
Paul J. Rullkoetter
Keyword(s):  
Finite Element ◽  
Contact Mechanics ◽  
Dynamic Loading ◽  
Soft Tissues ◽  
Dynamic Models ◽  
Total Joint Replacement ◽  
Fe Model ◽  
Loading Conditions ◽  
Dynamic Loading Conditions

The success of current total knee replacement (TKR) devices is contingent on the kinematics and contact mechanics during in vivo activity. Indicators of potential clinical performance of total joint replacement devices include contact stress and area due to articulations, and tibio-femoral and patello-femoral kinematics. An effective way of evaluating these parameters during the design phase or before clinical use is via computationally efficient computer models. Previous finite element (FE) knee models have generally been used to determine contact stresses and/or areas during static or quasi-static loading conditions. The majority of knee models intended to predict relative kinematics have not been able to determine contact mechanics simultaneously. Recently, however, explicit dynamic finite element methods have been used to develop dynamic models of TKR able to efficiently determine joint and contact mechanics during dynamic loading conditions [1,2]. The objective of this research was to develop and validate an explicit FE model of a TKR which includes tibio-femoral and patello-femoral articulations and surrounding soft tissues. The six degree-of-freedom kinematics, kinetics and polyethylene contact mechanics during dynamic loading conditions were then predicted during gait simulation.

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