An Externally Pressurized Supersonic Gas Thrust Bearing (1st Report, Static Characteristics in Supersonic Operations)

1984 ◽  
Vol 106 (1) ◽  
pp. 163-168
Author(s):  
Y. Miyake ◽  
T. Inaba ◽  
M. Hibi
Keyword(s):  
Gas Flow ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Static Characteristics ◽  
Flow Conditions ◽  
Gas Bearings ◽  
Bearing Clearance ◽  
Main Disadvantage ◽  
Bearing Stiffness ◽  
New Type

A completely new type of externally pressurized gas thrust bearing is proposed and its static characteristics are analyzed. Unlike conventional gas bearings whose load capacity depends on the viscosity of gas, the load capacity of this new type of bearing is independent of the viscosity of gas since it utilizes the choking phenomenon of gas flow to maintain high pressure in the bearing clearance. Also the change of the location of the throat generates bearing stiffness. Since the flow is supersonic at the exit of the bearing clearance, the flow conditions downstream of the exit do not affect the flow inside the bearing clearance. Accordingly, the load capacity increases proportionally to the supply pressure. Thus, the main disadvantage of conventional gas bearings, namely, the deficiency of their load capacity is overcome.

Static Characteristics of a Rectangular Hydrostatic Thrust Bearing With a Self-Controlled Restrictor Employing a Floating Disk

1993 ◽  
Vol 115 (2) ◽  
pp. 307-311 ◽  
Author(s):  
S. Yoshimoto ◽  
Y. Anno ◽  
M. Fujimura
Keyword(s):  
Flow Rate ◽  
Applied Load ◽  
Thrust Bearing ◽  
Static Characteristics ◽  
Hydrostatic Bearing ◽  
Supply Pressure ◽  
Wide Range ◽  
Bearing Stiffness ◽  
New Type ◽  
Very High

This paper proposes a new type of a self-controlled restrictor which can achieve a very high bearing stiffness in hydrostatic bearings. This self-controlled restrictor employs a floating disk to control the mass flow rate of the oil entering the bearing clearance according to changes of the applied load. Furthermore, a hydrostatic bearing with this restrictor can theoretically achieve an infinite stiffness when the mass of a floating disk is assumed to be zero. The static characteristics of a rectangular hydrostatic thrust bearing with this self-controlled restrictor are theoretically and experimentally investigated. It was consequently shown that the proposed hydrostatic thrust bearing can achieve a very high stiffness (nearly infinite stiffness) in a very wide range of applied load independent of supply pressure.

Numerical and experimental studies on the thermal and static characteristics of multi-leaf foil thrust bearing

2021 ◽  
pp. 135065012110110
Author(s):  
Yu Guo ◽  
Yu Hou ◽  
Qi Zhao ◽  
Xionghao Ren ◽  
Shuangtao Chen ◽  
...  
Keyword(s):  
High Speed ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Failure Process ◽  
Experimental Studies ◽  
Elastic Model ◽  
Static Characteristics ◽  
Bearing Load ◽  
Foil Thrust Bearing ◽  
Cooling Air

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.

Theoretical Study on Static Performance of Double-Bump Foil Bearings

2021 ◽  
Author(s):  
Fangcheng Xu ◽  
Jianhua Chu ◽  
Wenlin Luan ◽  
Guang Zhao
Keyword(s):  
Finite Element ◽  
Film Thickness ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Static Characteristics ◽  
Thrust Bearings ◽  
Foil Bearings ◽  
Foil Bearing ◽  
Static Performance ◽  
Initial Clearance

Abstract In this paper, single-bump foil models with different thickness and double-bump foil models with different initial clearances are established. The structural stiffness and equivalent viscous damping of double-bump foil and single-bump foil are analyzed by finite element simulation. The results show that the double-layer bump foil has variable stiffness and the displacement of the upper bump is greater than the initial gap when the two-layer bumps contact. A model for obtaining static characteristics of aerodynamic compliant foil thrust bearing is established on the basis of the stiffness characteristics of the double-bump foil. This paper solves gas Reynolds equation, the gas film thickness equation and the foil stiffness characteristic equation via the finite element method and the finite difference method. The static characteristics of the thrust bearings including the bearing pressure distribution, the gas film thickness and the friction power consumption have been obtained. The static characteristics of two kinds of foils have been compared and analyzed, and the effect of initial clearance on the static performance of double-bump foil bearings is studied. The results show that the double-bump foil structure can effectively improve the load capacity of thrust bearing. In addition, the static performance of double-bump foil thrust bearings is between the performance of the single-bump foil bearing and the double-bump foil bearing whose foil’s clearance is zero. The smaller the initial clearance is, the easier it will be to form a stable double-bump foil supporting structure.

scholarly journals Static characteristics of hydrostatic thrust bearing considering the inertia effect on the region of supply hole

2018 ◽  
Vol 233 (1) ◽  
pp. 188-193
Author(s):  
Zhuxin Tian ◽  
Haiyin Cao ◽  
Yu Huang
Keyword(s):  
Flow Rate ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Experimental Results ◽  
Inertia Effect ◽  
Static Characteristics ◽  
Hole Radius ◽  
Inertia Parameter ◽  
Theoretical Results ◽  
Inertia Theory

In the previous studies on the hydrostatic thrust bearing, the differences between the theoretical results and experimental results are obvious when the inertia parameter S and the ratio of supply hole radius to bearing radius r0/ R become large enough. To explain the differences, in this study, the inertia effect on the region of supply hole is considered in discussing the static characteristics of hydrostatic thrust bearing, and then new expressions of pressure, load capacity, and flow rate are given. For the continuous parallel bearing, the results of this study agree well with experiments, thus there is no need for the extra modified inertia theory. For the step bearing with a large inertia parameter (e.g., S = 2), the results of this study agree with experiments on the recess region, and are closer to the experimental results than those of old method on the region of bearing land. So when the inertia parameter S and the ratio of supply hole radius to bearing radius r0/ R are large enough, the inertia effect on the region of supply hole cannot be ignored in discussing the static characteristics of hydrostatic thrust bearing.

Static Characteristics of the Regular and Reversible Rotation Type Herringbone Grooved Journal Bearing

1989 ◽  
Vol 111 (3) ◽  
pp. 484-490 ◽  
Author(s):  
Nobuyoshi Kawabata ◽  
Yasumi Ozawa ◽  
Shuji Kamaya ◽  
Yutaka Miyake
Keyword(s):  
Numerical Analysis ◽  
Journal Bearing ◽  
Load Capacity ◽  
Maximum Load ◽  
Radial Load ◽  
Static Characteristics ◽  
Oil Film ◽  
New Type ◽  
Load Component ◽  
Reversible Rotation

A new type herringbone grooved journal bearing, which produces an oil film bearing pressure with a shaft or bearing rotation in either direction, is proposed in this paper. A numerical analysis of the bearing parameters using the narrow groove theory and the Gu¨mbel condition confirmed that the load capacity of this bearing and the radial load component (related to stability) do not differ greatly from those of a conventional bearing. The values of the bearing parameters which give maximum load capacity, and the values of the load capacity and its direction angle are also determined numerically for the case of either grooved member or smooth member rotation.

The Static Characteristics of Bump Foil Thrust Bearing Considering Tilting Condition

2009 ◽  
Author(s):  
Tae-Young Kim ◽  
Dong-Jin Park ◽  
Yong-Bok Lee
Keyword(s):  
High Efficiency ◽  
Thrust Bearing ◽  
Numerical Models ◽  
Load Capacity ◽  
Static Characteristics ◽  
Thrust Bearings ◽  
Foil Bearings ◽  
Foil Thrust Bearing ◽  
Thrust Pad ◽  
Air Film

Air foil thrust bearings are the critical component available on high-efficiency turbomachinery which needs ability to endure the large axial force. Previous investigations about the static characteristics were obtained over the region of the thin air film using finite-difference method and the characteristics of the corrugated bump foil using finite-element method. Moreover, a recent study demonstrated that bearing performance is sensitive to tilting thrust pad condition. In this study, experimentally measured bearing static characteristics are compared with the numerical model of the foil thrust bearing considering tilting pad condition. Three geometrically different type foil bearings were tested to measure their load capacity under tilting conditions that have continuous angles from zero to 0.0002 rad. These data are presented for use i1n the development of more accurate foil thrust bearing numerical models.

An Externally Pressurized Supersonic Gas Thrust Bearing (2nd Report, Dynamic Characteristics in Supersonic Operations and Static Characteristics in Sonic Operations)

1984 ◽  
Vol 106 (1) ◽  
pp. 169-173
Author(s):  
Y. Miyake ◽  
T. Inaba ◽  
T. Matsuoka
Keyword(s):  
Dynamic Characteristics ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Damping Factor ◽  
Static Characteristics ◽  
Supply Pressure

The dynamic characteristics of a newly proposed supersonic gas thrust bearing are analyzed under supersonic operations. Its static characteristics in sonic operations are also investigated. It is concluded that the load capacity, the stiffness factor, and the damping factor are increased proportionally to the supply pressure in either supersonic or sonic operation range which is determined according to the magnitude of the clearance.

Static Axial Characteristics of Aerostatic Annular Porous Thrust Bearings with Tilt

1983 ◽  
Vol 197 (2) ◽  
pp. 83-88 ◽  
Author(s):  
K C Singh ◽  
N S Rao ◽  
B C Majumdar
Keyword(s):  
Gas Flow ◽  
Load Capacity ◽  
Three Dimensional ◽  
Graphical Form ◽  
Axial Stiffness ◽  
Mass Rate ◽  
Thrust Bearings ◽  
Bearing Clearance ◽  
Mass Flowrate ◽  
Flow Through

A theoretical analysis is presented to predict the static axial performance characteristics of a porous circular thrust bearing with a central hole for both open and sealed ends, taking into consideration the tilt of the runner pad. The flow in the bearing matrix is considered to be three-dimensional. The governing equations of gas flow through the porous pad and the bearing clearance are solved simultaneously using the finite difference technique to obtain pressure distribution in the bearing clearance. The load capacity, mass rate of flow and static axial stiffness are calculated numerically for various bearing dimensions and supply conditions and presented in graphical form. The bearings with sealed ends have comparatively better load capacity over those with unsealed ends. The effect of tilt is to decrease the load capacity and increase the mass flowrate.

ANALYSIS OF BEARING CLEARANCE AND WIDTH OF AN OIL GROOVE ON THE CHARACTERISTIC OF FLUID FILM IN HYDRODYNAMIC MAIN CRANKSHAFT BEARINGS

Tribologia ◽  
2018 ◽  
Vol 281 (5) ◽  
pp. 159-167
Author(s):  
Tomasz ŻOCHOWSKI ◽  
Artur OLSZEWSKI
Keyword(s):  
Working Conditions ◽  
Load Capacity ◽  
High Volume ◽  
Machine Construction ◽  
Vehicle Design ◽  
Static Characteristics ◽  
Bearing Clearance ◽  
High Volume Production ◽  
Volume Production ◽  
Bearing Analysis

Paper represents an analysis of the influence of oil groove width and bearing clearance on the characteristics of oil film in a hydrodynamic journal main crankshaft bearing. Analysis was performed to define the influence of bearing clearance and dimensions of oil grooves on static characteristics and manufacturability of half-shelf bearings in industrial high-volume production. Computer simulations were made using an ARTbear program, which was developed in Department of Machine Construction and Vehicle Design in Gdańsk Technical University. The analysis allowed defining the correlation between groove geometry and load capacity and working conditions of bearings. Potential opportunities of possible shortening of production time in high-volume production were also indicated.

Analysis of Externally Pressurized, Double-Pad, Gas Porous Thrust Bearing

1983 ◽  
Vol 105 (1) ◽  
pp. 113-119 ◽  
Author(s):  
K. H. Wu ◽  
C. Cusano
Keyword(s):  
Thrust Bearing ◽  
Load Capacity ◽  
Gas Bearings ◽  
Maximum Value

The load capacity and stiffness of double-pad circular and rectangular porous gas bearings are analytically studied. Design curves for load capacity and stiffness versus static bearing numbers, for different supply pressures and eccentricity ratios, are given. The load capacity and stiffness of both bearings reach a maximum value at some bearing numbers and then decrease. A comparison between the load capacity and stiffness of single and double-pad gas bearings is made.

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