Research on Thermal Characteristics of Spindle System With Tilting Pad Bearing

2018 ◽  
Vol 10 (5) ◽  
Author(s):  
Shuyun Jiang ◽  
Deyang Shen
Keyword(s):  
Power Loss ◽  
Thermal Model ◽  
Thermal Characteristics ◽  
The Finite Element Method ◽  
Spindle System ◽  
Friction Power ◽  
Heat Transfer Theory ◽  
Lubricant Flow ◽  
Tilting Pad ◽  
Tilting Pad Bearings

Spindles with tilting pad bearings have been widely applied in machine tools due to their high running precision. However, friction power loss will increase dramatically when the bearing runs at a higher speed. So far, little research on the thermal modeling of spindle systems with tilting pad bearings can be found in literature. In this paper, based on the Newtonian law of viscosity, formula that describes the friction power loss of the tilting pad bearing has been derived. The thermodynamic equilibrium equation for the spindle lubrication system has been established. Thermal boundary condition of the spindle system has been obtained using the heat transfer theory. Thermal model of the spindle system with tilting pad bearing has been built with the finite element method in order to calculate its temperature and thermal displacement distribution. Effects of the eccentricity ratio and the lubricant flow rate on thermodynamic behavior of the spindle system have been studied systematically. Finally, experiments have been conducted to verify the proposed thermal model for the spindle system with tilting pad bearing.

Reducing Friction in Tilting-Pad Bearings by the Use of Enclosed Recesses

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Niels Heinrichson ◽  
Ilmar Ferreira Santos
Keyword(s):  
Power Loss ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Accurate Analysis ◽  
Pivot Point ◽  
Analysis And Design ◽  
Sliding Direction ◽  
Tilting Angle ◽  
Tilting Pad ◽  
Tilting Pad Bearings

A three-dimensional thermoelastohydrodynamic model is applied to the analysis of tilting-pad bearings with spherical pivots and equipped with deep recesses in the high-pressure regions. A potential for a 10–20% reduction in the friction loss compared to conventional plain bearing pads is documented. Design suggestions minimizing the power loss are given for various length-to-width ratios. The tilting angle in the sliding direction is more sensitive to correct positioning of the pivot point than conventional bearing pads. Improving the performance by equipping a tilting-pad bearing with a deep recess therefore requires accurate analysis and design of the bearing. Similarly, a high sensitivity perpendicular to the sliding direction suggests that this method of reducing friction is more feasible when using line pivots or spring beds than when using spherical pivots for controlling the tilting angle.

Reduction of Vibration and Power Loss in Industrial Turbochargers With Improved Tilting Pad Bearing Design

2015 ◽  
Author(s):  
Jianming Cao ◽  
Timothy Dimond ◽  
Paul Allaire
Keyword(s):  
Rotational Speed ◽  
Power Loss ◽  
Internal Combustion Engines ◽  
Low Cost ◽  
Stability Margin ◽  
Reciprocating Compressor ◽  
Automotive Applications ◽  
Run Off ◽  
Tilting Pad ◽  
Tilting Pad Bearings

Turbochargers are commonly used in reciprocating compressors and internal combustion engines to improve overall efficiency, thereby reducing fuel requirements. In reciprocating compressor applications, turbochargers typically operate in the range of 15,000 rpm to 30,000 rpm. These turbomachines operate at higher rotational speed in automotive applications, often exceeding 100,000 rpm. These high speeds result in bearings that are often highly non-linear, with large limit cycle shaft orbits and high subsynchronous vibration levels. These large orbits also result in much higher power losses than would be observed for the same bearing with low vibration levels. These devices are often used in automotive applications, where there are significant cost pressures, ruling out more expensive bearing options such as tilting pad bearings. There is a need for bearing designs that are effective at stabilizing turbochargers and are also low cost. In this paper, a theoretical turbocharger for a reciprocating compressor application is considered. The initial design incorporated plain axial groove bearings. Several replacement bearing options were considered, including pressure dam bearings and tilting pad bearings to improve rotor stability. The pressure dam bearing is used to impose a load on the shaft, making it run off center. This feature reduces subsynchronous whirl instability and also reduces power loss. The tilting pad bearing eliminates self-excited forces from the bearings but has increased power loss when compared to fixed-pad bearings. Starved lubrication of the tilting pad bearing reduced the power loss but also reduced the stability margin. The application considered for this paper is a larger turbocharger with a rotational speed of 25,000 rpm, and is unstable with conventional bearings.

scholarly journals On the Possibilities of Decreasing Power Loss in Large Tilting Pad Thrust Bearings

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Michal Wasilczuk ◽  
Grzegorz Rotta
Keyword(s):  
Power Loss ◽  
Power Plants ◽  
Thrust Bearing ◽  
Fluid Film ◽  
Total Power ◽  
Thrust Bearings ◽  
Oil Supply ◽  
Water Power ◽  
Lubricant Flow ◽  
Tilting Pad

Different systems of direct oil supply have been developed in order to facilitate efficient introduction of fresh lubricant to the oil gap and reduction of churning power loss in tilting pad thrust bearings. Up to now there is no documented application of the supply groove in large thrust bearings used in water power plants. The results of modeling lubricant flow in the lubricating groove of a thrust bearing pad will be presented in the paper. CFD software was used to carry out fluid film calculations. Such analysis makes it possible to modify groove geometry and other parameters and to study their influence on bearing performance. According to the results a remarkable decrease in total power loss due to avoiding churning losses can be observed in the bearing.

scholarly journals A general thermal model of machine tool spindle

2017 ◽  
Vol 9 (1) ◽  
pp. 168781401668630
Author(s):  
Yanfang Dong ◽  
Zude Zhou ◽  
Mingyao Liu
Keyword(s):  
Machine Tool ◽  
Thermal Model ◽  
Thermal Characteristics ◽  
Thermal Error ◽  
Major Axis ◽  
Heat Sinks ◽  
Semi Major Axis ◽  
Spindle System ◽  
Rolling Elements ◽  
Deformation Coefficient

As the core component of machine tool, the thermal characteristics of the spindle have a significant influence on machine tool running status. Lack of an accurate model of the spindle system, particularly the model of load–deformation coefficient between the bearing rolling elements and rings, severely limits the thermal error analytic precision of the spindle. In this article, bearing internal loads, especially the function relationships between the principal curvature difference F( ρ) and auxiliary parameter nδ, semi-major axis a, and semi-minor axis b, have been determined; furthermore, high-precision heat generation combining the heat sinks in the spindle system is calculated; finally, an accurate thermal model of the spindle was established. Moreover, a conventional spindle with embedded fiber Bragg grating temperature sensors has been developed. By comparing the experiment results with simulation, it indicates that the model has good accuracy, which verifies the reliability of the modeling process.

On the Effect of Pad Clearance and Preload Manufacturing Tolerances on Tilting Pad Bearings Rotordynamic Coefficients

2013 ◽  
Author(s):  
Jose L. Gomez ◽  
Saira Pineda ◽  
Sergio E. Diaz
Keyword(s):  
High Speed ◽  
Numerical Study ◽  
Numerical Code ◽  
Perturbation Approach ◽  
The Finite Element Method ◽  
Rotordynamic Coefficients ◽  
Dynamic Coefficients ◽  
Tilting Pad ◽  
Manufacturing Tolerances ◽  
Tilting Pad Bearings

Tilting pad bearings (TPB) are commonly used in high-speed and high-power turbomachines, due to its contributions in avoiding rotor instabilities. Studies related to the estimation of dynamic coefficients have been carried out considering a uniform value of the geometric parameters (clearance, pre-load) for all bearing pads. These assumptions give a reasonable agreement on the direct coefficients prediction while, recently, some discrepancies have been found on the cross-coupled coefficients. In this work, a numerical study is devised to analyze the influence of the pre-load and clearance variations from pad to pad, due to manufacturing tolerances, on the dynamic coefficients prediction. The numerical code for the estimation of the dynamic coefficients uses the finite element method to integrate the Reynolds’s equation through a perturbation approach. Variations on the pre-load and clearance for each bearing’s pad were performed, producing plots quantifying the sensitivity of the tilting pad bearing cross coupled coefficients to manufacturing tolerances.

Constrained Design Optimization of Rotor-Tilting Pad Bearing Systems

2010 ◽  
Vol 132 (12) ◽  
Author(s):  
Costin D. Untaroiu ◽  
Alexandrina Untaroiu
Keyword(s):  
Design Optimization ◽  
Power Loss ◽  
Optimization Design ◽  
Optimization Approach ◽  
Design Variables ◽  
Tilting Pad ◽  
Rotor Bearing ◽  
Automatic Optimization ◽  
Tilting Pad Bearings ◽  
Bearing System

Design of a rotor-bearing system is a challenging task due to various conflicting design requirements, which should be fulfilled. This study considers an automatic optimization approach for the design of a rotor supported on tilting-pad bearings. A numerical example of a rotor-bearing system is employed to demonstrate the merits of the proposed design approach. The finite element method is used to model the rotor-bearing system, and the dynamic speed-dependent coefficients of the bearing are calculated using a bulk flow code. A number of geometrical characteristics of the rotor simultaneously with the parameters defining the configuration of tilting pad bearings are considered as design variables into the automatic optimization process. The power loss in bearings, stability criteria, and unbalance responses are defined as a set of objective functions and constraints. The complex design optimization problem is solved using heuristic optimization algorithms, such as genetic, and particle-swarm optimization. Whereas both algorithms found better design solutions than the initial design, the genetic algorithms exhibited the fastest convergence. A statistical approach was used to identify the influence of the design variables on the objective function and constraint measures. The bearing clearances, preloads and lengths showed to have the highest influence on the power loss in the chosen design space. The high performance of the best solution obtained in the optimization design suggests that the proposed approach has good potential for improving design of rotor-bearing systems encountered in industrial applications.

Lubricating Characteristics of Circular Tilting Pad Thrust Bearing

2010 ◽  
Vol 148-149 ◽  
pp. 267-270
Author(s):  
Xiao Dong Yu ◽  
Hui Jiang ◽  
Xiu Li Meng ◽  
Hong Jun Xiang ◽  
Hai Peng Yu ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Power Loss ◽  
Thrust Bearing ◽  
Thickness Distribution ◽  
The Finite Element Method ◽  
Oil Film ◽  
Heavy Equipment ◽  
Tilting Pad ◽  
Actual Design ◽  
Oil Film Pressure

In order to solve lubricating problem of circular tilting pad thrust bearing in the heavy equipment, lubricating characteristics mathematical model is established based on the Computational Fluid Dynamics and lubricating theory, the Finite Element Method is used to compute the lubricating characteristics of a circular tilting pad thrust bearing, and figure out thickness distribution of oil film, pressure distribution of oil film, temperature distribution of oil film, power loss and fluid flow, etc. lubricating characteristics parameters by self-compiling software program. Experiments testify the validity of the lubricating characteristics mathematical model. Through this method, the safety of a circular tilting pad thrust bearing can be forecasted, and the optimal design of such products can be achieved, and provides reasonable data for actual design and experiment, and decreases economy loss.

Influence of new surface micro-structures on the performance behaviours of fluid film tilting pad thrust bearings

2021 ◽  
pp. 095440622110309
Author(s):  
JC Atwal ◽  
RK Pandey
Keyword(s):  
Mass Conservation ◽  
Performance Parameters ◽  
Algebraic Equations ◽  
The Finite Element Method ◽  
Thrust Bearings ◽  
Lubrication Equation ◽  
Tilting Pad ◽  
Minimum Film Thickness ◽  
Newton Raphson ◽  
Micro Structures

Performance parameters such as power loss, minimum film thickness, and maximum oil temperature of the sector-shaped tilting pad thrust bearings employing the new micro-structural geometries on pad surfaces have been investigated. The lubrication equation incorporating the mass-conservation issue is discretized using the finite element method and the solution of resulting algebraic equations is obtained employing a Newton-Schur method. The pad equilibrium in the analysis is established using the Newton-Raphson and Braydon methods. The influence of attributes of micro-structures such as depth, circumferential and radial positioning extents have been explored on the performance behaviours. It is found that with the new micro-structured pad surfaces, the performance parameters significantly improved in comparison to conventional plain and conventional rectangular pocketed pads.

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