Method for Solution of Lubrication Problems With Temperature and Elasticity Effects: Application to Sector, Tilting-Pad Bearings

1969 ◽  
Vol 91 (4) ◽  
pp. 634-640 ◽  
Author(s):  
V. Castelli ◽  
S. B. Malanoski
Keyword(s):  
Elastic Deformation ◽  
Efficient Method ◽  
Simultaneous Solution ◽  
Thrust Bearings ◽  
Variational Techniques ◽  
Tilting Pad ◽  
Tilting Pad Bearings ◽  
Energy Equations ◽  
Elasticity Effects

The importance of temperature and elasticity effects in bearings have been demonstrated by several authors. This paper offers an efficient method for the simultaneous solution of the Reynolds and energy equations and their coupling with elastic deformation results obtained by variational techniques. Results are presented for centrally pivoted, tilting-pad, sector, thrust bearings.

Studies in hydronamic thrust bearings I. Theory considering thermal and elastic distortions

1975 ◽  
Vol 278 (1283) ◽  
pp. 351-366 ◽  
Keyword(s):  
Biharmonic Equation ◽  
The Other ◽  
Direct Compression ◽  
Simultaneous Solution ◽  
Thrust Bearings ◽  
Plate Flexure ◽  
Thermal Bending ◽  
Set Up ◽  
Thrust Pad ◽  
Energy Equations

The distortions of a thrust pad and its runner are analysed by solving the biharmonic equation of plate flexure by both elastic and thermal causes. The temperature and pressures are obtained from the simultaneous solution of the Reynolds and energy equations. The major similification is the assumption of constant temperature through the thickness of the oil film, though it varies in both the other directions. The equations are set up and their reduction to a form suitable for computing is described. Four modes of distortion are considered, pressure and thermal bending, direct compression and direct thermal expansion.

Starting Phenomena of Tilting Pad Bearings

2001 ◽  
Author(s):  
C. F. Kettleborough
Keyword(s):  
Critical Points ◽  
Relative Velocity ◽  
Applied Load ◽  
Initial Conditions ◽  
Important Influence ◽  
Oil Film ◽  
Thrust Bearings ◽  
Tilting Pad ◽  
Oil Pockets ◽  
Tilting Pad Bearings

Abstract The starting of large thrust bearings in turbines is one of the most critical points in their operation as a pressure carrying oil film must be generated from initial conditions of load and zero relative velocity between the two surfaces. A force equal and opposite to the applied load must be produced before the surfaces separate. It is the purpose of this paper to discuss the origin and formation of this force. The results show that lapped and ground surfaces have inefficient lifting characteristics as compared with surfaces having irregularities on the surface of 1/20 mil and greater. In general, surface oil pockets have an important influence on the starting behavior of tilting pad bearings; without these oil pockets it is doubtful if the two bearing surfaces would part.

Bump-Type Foil Bearings and Flexure Pivot Tilting Pad Bearings for Oil-Free Automotive Turbochargers: Highlights in Rotordynamic Performance

2015 ◽  
Author(s):  
Keun Ryu ◽  
Zachary Ashton
Keyword(s):  
High Performance ◽  
Load Capacity ◽  
Mechanical Efficiency ◽  
Outer Diameter ◽  
Gas Bearings ◽  
Thrust Bearings ◽  
Foil Bearings ◽  
Thermal Growth ◽  
Tilting Pad ◽  
Tilting Pad Bearings

Oil-free turbochargers require gas bearings in compact units of enhanced rotordynamic stability, mechanical efficiency, and improved reliability with reduced maintenance costs compared with oil-lubricated bearings. Implementation of gas bearings into automotive turbochargers requires careful thermal management with accurate measurements verifying model predictions. Foil bearings are customarily used in oil-free microturbomachinery because of their distinct advantages including tolerance to shaft misalignment and centrifugal/thermal growth, and large damping and load capacity compared with rigid surface gas bearings. Flexure pivot tilting pad bearings are widely used in high performance turbomachinery since they offer little or no cross-coupled stiffnesses with enhanced rotordynamic stability. The paper details the rotordynamic performance and temperature characteristics of two prototype oil-free turbochargers; one supported on foil journal and thrust bearings and the other one is supported on flexure pivot tilting pad journal bearings and foil thrust bearings of identical sizes (OD and ID) with the same aerodynamic components. The tests of the oil-free turbochargers, each consisting of a hollow rotor (∼0.4 kg and ∼23 mm in outer diameter at the bearing locations), are performed for various imbalances in NVH (i.e, cold air driven rotordynamics rig) and gas stand test facilities up to 130 krpm. No forced cooling air flow streams are supplied to the test bearings and rotor. The measurements demonstrate the stable performance of the rotor-gas bearing systems in an ambient NVH test cell with cold forced air into the turbine inlet. Posttest inspection of the test flexure pivot tilting pad bearings after the hot gas stand tests evidences seizure of the hottest bearing, thereby revealing a notable reduction in bearing clearance as the rotor temperature increases. The compliant flexure pivot tilting pad bearings offer a sound solution for stable rotor support only at an ambient temperature condition while demonstrating less tolerance for shaft growth, centrifugal and thermal, beyond its clearance. The current measurements give confidence in the present gas foil bearing technology for ready application into automotive turbochargers for passenger car and commercial vehicle applications with increased reliability.

Turbulent Lubrication of Tilting-Pad Thrust Bearings With Thermal and Elastic Deformations

1985 ◽  
Vol 107 (1) ◽  
pp. 82-86 ◽  
Author(s):  
H. Hashimoto ◽  
S. Wada
Keyword(s):  
Friction Torque ◽  
Shaft Speed ◽  
Centrifugal Forces ◽  
Balance Equations ◽  
Elastic Deformations ◽  
Film Pressure ◽  
Thrust Bearings ◽  
Temperature Distributions ◽  
Tilting Pad ◽  
Energy Equations

Pad deformations of sector-shaped, tilting-pad thrust bearings affecting turbulent lubrication are discussed theoretically. Solving the lubrication and energy equations with turbulence and centrifugal forces and the elastic and moment balance equations of a pad simultaneously, film pressure and temperature distributions, thermal and elastic deformations and inclinations of a pad are obtained. Film thicknesses at a pivot under a constant shaft speed become larger due to pad deformations, whereby pad inclinations increase and friction torque coefficients decrease outstandingly. It is important to introduce the effects of pad deformations when analysing performances of such bearings running in the turbulent conditions.

Bump-Type Foil Bearings and Flexure Pivot Tilting Pad Bearings for Oil-Free Automotive Turbochargers: Highlights in Rotordynamic Performance

2015 ◽  
Vol 138 (4) ◽  
Author(s):  
Keun Ryu ◽  
Zachary Ashton
Keyword(s):  
High Performance ◽  
Load Capacity ◽  
Mechanical Efficiency ◽  
Outer Diameter ◽  
Gas Bearings ◽  
Thrust Bearings ◽  
Foil Bearings ◽  
Thermal Growth ◽  
Tilting Pad ◽  
Tilting Pad Bearings

Oil-free turbochargers (TCs) require gas bearings in compact units of enhanced rotordynamic stability, mechanical efficiency, and improved reliability with reduced maintenance costs compared with oil-lubricated bearings. Implementation of gas bearings into automotive TCs requires careful thermal management with accurate measurements verifying model predictions. Gas foil bearings (GFBs) are customarily used in oil-free microturbomachinery because of their distinct advantages including tolerance to shaft misalignment and centrifugal/thermal growth, and large damping and load capacity compared with rigid surface gas bearings. Flexure pivot tilting pad bearings (FPTPBs) are widely used in high-performance turbomachinery since they offer little or no cross-coupled stiffnesses with enhanced rotordynamic stability. The paper details the rotordynamic performance and temperature characteristics of two prototype oil-free TCs; one supported on foil journal and thrust bearings and the other one is supported on FPTP journal bearings and foil thrust bearings of identical sizes (outer diameter (OD) and inner diameter (ID)) with the same aerodynamic components. The tests of the oil-free TCs, each consisting of a hollow rotor (∼0.4 kg and ∼23 mm in OD at the bearing locations), are performed for various imbalances in noise, vibration, and harshness (NVH; i.e., cold air driven rotordynamics rig) and gas stand test facilities up to 130 krpm. No forced cooling air flow streams are supplied to the test bearings and rotor. The measurements demonstrate the stable performance of the rotor–gas bearing systems in an ambient NVH test cell with cold forced air into the turbine inlet. Post-test inspection of the test FPTPGBs after the hot gas stand tests evidences seizure of the hottest bearing, thereby revealing a notable reduction in bearing clearance as the rotor temperature increases. The compliant FPTPGBs offer a sound solution for stable rotor support only at an ambient temperature condition while demonstrating less tolerance for shaft growth, centrifugal, and thermal, beyond its clearance. The current measurements give confidence in the present GFB technology for ready application into automotive TCs for passenger car and commercial vehicle applications with increased reliability.

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.

Electrical pitting of tilting-pad thrust bearings: Modelling and experimental evidence

2016 ◽  
Vol 103 ◽  
pp. 475-486 ◽  
Author(s):  
Steven Chatterton ◽  
Paolo Pennacchi ◽  
Andrea Vania
Keyword(s):  
Experimental Evidence ◽  
Thrust Bearings ◽  
Tilting Pad
Sign in / Sign up

Export Citation Format

Share Document