The Analysis and Design of Turbocharger Thrust Bearing

2011 ◽  
Vol 308-310 ◽  
pp. 1333-1336 ◽  
Author(s):  
Li Jun Qiu ◽  
Jia Yang ◽  
Su Ying Xu

Turbocharger turbine shaft thrust bearing is the role of high-speed rotating turbine to withstand the axial force generated by the turbine shaft and a part of the axial position. Fixed on the intermediate thrust bearing on the two sides and both sides of the ring, respectively, relative sliding. Sliding contact surface produces a condition of dynamic pressure oil film structure and shape of the oil wedge. Bearing the sides of the structural design of the oil wedge slot and forming a design to solve the main content. Bearing thrust bearing stiffness and rotation in the process of stress state and the smooth line is to improve the bearing life. Rotating turbine shaft to ensure the accuracy of key factors. Method of lubricating oil to the oil and oil Xie in the shape and precision bearings to ensure the prerequisite conditions and service life.

Author(s):  
Wenwu Wu ◽  
Jun Hong ◽  
Xiaohu Li ◽  
Yang Li ◽  
Baotong Li

With the increasing demand of higher operating speed for bearing system, more challenges have been exposed on the maintaining of the bearing performance. Preloading is an effective method to handle these challenges. Traditionally, the preloading of bearing system has been applied by uniform approaches such as rigid preload and constant preload. However, this treatment may hardly deal with the optimization of preloading problem due to the non-uniformity of the bearing stiffness becomes more apparent under high-speed operating conditions. A novel and practical approach is therefore presented in this paper to incorporate the non-uniformity effect to improve the structural performance of bearing under actual operating conditions. Firstly, the critical relationship between the stiffness behaviour and the non-uniform preload is evaluated for bearing system. The stiffness problem of angular contact ball bearing system is then formulated analytically by Jones’ model. With this approach, boundary conditions are achieved to solve the local contact deformation and predict the bearing life under non-uniform preload. Finally, both the uniform preload and the non-uniform preload cases for bearing system are simulated under various operating conditions. Comparing with traditional methods, the proposed method can provide a better solution in both stiffness and life that will enable a designer to obtain a deep insight on the optimization of bearing system.


2002 ◽  
Vol 125 (1) ◽  
pp. 95-101 ◽  
Author(s):  
B. C. Pettinato ◽  
P. DeChoudhury

The paper discusses the redesign of a high-speed turbocharger for improved bearing life and mechanical operation. The bearings were changed from a pair of combination journal/thrust bearings to a pair of redesigned journal bearings with double acting thrust bearing at the center of the unit. Internal oil passages, drain cavities, and seals were also revised. These modifications resulted in reduced oil leakage across end seals, reduced coke buildup at the turbine, increased thrust load capacity, and improved rotordynamics. Both the analytical and experimental results, which consisted of bearing performance and vibration data of original and modified systems are presented.


2013 ◽  
Vol 365-366 ◽  
pp. 304-308
Author(s):  
Lei Wang

An analysis is conducted and solutions are provided for the dynamic performance of high speed hybrid thrust bearing. By adopting bulk flow theory, the turbulent Reynolds equation is solved numerically with the different orifice diameter and supply pressure. The results show that increasing supply pressure can significantly improve the bearing stiffness and damping, while the orifice diameters make a different effect on the bearing stiffness and damping.


Author(s):  
Brian C. Pettinato ◽  
Pranabesh DeChoudhury

The paper discusses the redesign of a high-speed turbocharger for improved bearing life and mechanical operation. The modifications resulted in reduced oil leakage across the end seal, reduced coke buildup at the turbine, increased thrust load capacity, and improved rotordynamics. In particular, rotordynamic stability was improved by eliminating subsynchronous vibration at the operating speed. The redesign consisted of changing the bearings from a pair of combination journal/thrust bearings to a pair of journal bearings and a double acting thrust bearing at the center of the unit. The active thrust bearing was moved away from the hot turbine end of the machine. The thrust bearing geometry was modified for increased minimum film thickness, reduced metal temperature, and increased load capacity. Inlet and drain passages were revised for better oil flow distribution. Unit rotordynamics were improved by upgrading the journal bearings from three-axial-groove to three-lobe design. The upgraded unit kept the same footprint as the original design with only piping modifications required. Extensive analysis and testing were conducted. Testing of the original and revised turbochargers showed improvements in the redesign with reduced bearing metal temperatures and improved rotordynamic stability. Theoretical results along with test data consisting of bearing performance and vibration data of the original and modified system are presented in this paper.


2019 ◽  
Vol 71 (3) ◽  
pp. 467-473 ◽  
Author(s):  
Mubing Yu ◽  
Xiaodong Yu ◽  
Xuhang Zheng ◽  
Hui Jiang

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.


2010 ◽  
Vol 655 ◽  
pp. 446-471 ◽  
Author(s):  
J. E. GARRATT ◽  
K. A. CLIFFE ◽  
S. HIBBERD ◽  
H. POWER

A compressible air-flow model is introduced for the thin film dynamics of a highly rotating squeeze-film thrust bearing. The lubrication approximation to the Navier–Stokes equations for compressible flow leads to a modified Reynolds equation incorporating additional rotation effects. To investigate the dynamics of the system, the axial position of the bearing stator is prescribed by a finite-amplitude periodic forcing. The dynamics of the squeeze-film are modelled in the uncoupled configuration where the axial position of the rotor is fixed. The coupled squeeze-film bearing dynamics are investigated when the axial position of the rotor is modelled as a spring-mass-damper system that responds to the film dynamics. Initially the uncoupled squeeze-film dynamics are considered at low operating speeds with the classical Reynolds equation for compressible flow. The limited value of the linearized small-amplitude results is identified. Analytical results indicate that finite-amplitude forcing needs to be considered to gain a complete understanding of the dynamics. Using a Fourier spectral collocation numerical scheme, the periodic bearing force is investigated as a nonlinear function of the frequency and amplitude of the stator forcing. High-speed bearing operation is modelled using the modified Reynolds equation. A steady-state analysis is used to identify the effect of rotation and the rotor support properties in the coupled air-flow–structure model. The unsteady coupled dynamics are computed numerically to determine how the rotor support structures and the periodic stator forcing influence the system dynamics. The potential for resonant rotor behaviour is identified through asymptotic and Fourier analysis of the rotor motion for small-amplitude, low-frequency oscillations in the stator position for key values of the rotor stiffness. Through the use of arclength continuation, the existence of resonant behaviour is identified numerically for a range of operating speeds and forcing frequencies. Changes in the minimum rotor–stator clearance are presented as a function of the rotor stiffness to demonstrate the appearance of resonance.


Author(s):  
Yanan Feng ◽  
Xiaodong Yu ◽  
Zelin Han ◽  
Shihao Li ◽  
Bangyao Tang ◽  
...  

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.


Author(s):  
Yu Guo ◽  
Yu Hou ◽  
Qi Zhao ◽  
Xionghao Ren ◽  
Shuangtao Chen ◽  
...  

Foil bearing is considered to be a promising supporting technology in high-speed centrifugal machinery. Due to the high-speed shearing effect in the viscous lubricant film, heat generation could not be ignored. In this paper, a thermo-elastic model of the multi-leaf foil thrust bearing is proposed to predict its thermal and static characteristics. In the model, modified Reynolds equation, energy equation, and Kirchhoff equation are solved in a coupling way. The contact area between the foil and welding plate is taken into account. Besides, the effect of cooling air on the bearing temperature is investigated. The ultimate load capacity and transient overload failure process of the bearing is analyzed and discussed. The effect of rotation speed on the bearing temperature is more obvious than that of the bearing load. The bearing temperature drops obviously by introducing the cooling air, and the cooling effect is improved with the supply pressure. The transient overload failure of the bearing occurs when the bearing load exceeds the ultimate value.


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