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.

Static Characteristics of a Slot-Entry Gas Journal Bearing With Feeding Holes

1988 ◽  
Vol 110 (4) ◽  
pp. 587-591 ◽  
Author(s):  
S. Yoshimoto
Keyword(s):  
Gas Flow ◽  
Journal Bearing ◽  
Load Capacity ◽  
Maximum Load ◽  
Viscous Resistance ◽  
Narrow Gap ◽  
Static Characteristics ◽  
Theoretical Predictions ◽  
The Finite Difference Method ◽  
Gas Journal Bearing

This paper describes the static characteristics of a slot-entry gas journal bearing with feeding holes. Gas flow in this bearing is restricted first by inflow resistance when gas rapidly flows into the narrow gap of the slot region from isolated feeding holes, and then, restricted more by viscous resistance in the slot region. Therefore, the maximum load capacity and stiffness in this type of bearing can be easily obtained even in a very small bearing clearance of less than 10 μm because gas flow entering the journal can be restricted to a very small amount. Here, the static characteristics of this type of bearings are determined numerically by using the finite difference method. The validity of the theoretical predictions is confirmed by comparison with the experimental results.

Static characteristics of six pads multilayer protuberant foil thrust bearings

2016 ◽  
Vol 231 (2) ◽  
pp. 158-164 ◽  
Author(s):  
Yueqing Zheng ◽  
Tianwei Lai ◽  
Shuangtao Chen ◽  
Liang Chen ◽  
Liqiang Liu ◽  
...  
Keyword(s):  
Rotational Speed ◽  
Load Capacity ◽  
Maximum Load ◽  
Experimental Results ◽  
Load Force ◽  
Static Characteristics ◽  
Thrust Bearings ◽  
Foil Bearing ◽  
New Type ◽  
Proportional Relationship

The multilayer protuberant foil bearing, as a new type of compliant surface foil bearing, shows a great and wide application promise. Six pads multilayer protuberant foil thrust bearings with different configurations were designed and fabricated in this study. The static characteristics of these bearings and the effects of their key configuration parameters including the thickness of top foil, the thickness of protuberant foil, and the layers of protuberant foil are investigated. The experimental results reveal that the bearings show nonconstant structural stiffness, and the stiffness mainly depends on both the load force and the configuration of the bearings. In the airborne regime, the torque of the bearing is mainly dependent on the load force rather than the rotational speed, which can be interpreted by the proportional relationship between the bearing clearance and the rotational speed. Furthermore, the experimental results also show that the maximum load capacities of the bearing are also greatly affected by the bearing configuration. With more layers of the protuberant foils and thinner top foil, the bearing shows larger maximum load capacity. The work provides some insights about the relationships between the characteristics and the configuration of the bearings.

The Influence of Surface Roughness on Elastohydrodynamic Journal Bearing With Non-Newtonian Lubricants

2005 ◽  
Author(s):  
Mongkol Mongkolwongrojn ◽  
Chatchai Aiumpornsin ◽  
Somnuk Yawong
Keyword(s):  
Surface Roughness ◽  
Elastic Deformation ◽  
Journal Bearing ◽  
Load Capacity ◽  
Elastohydrodynamic Lubrication ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Static Characteristics ◽  
Heavy Load ◽  
Oil Film

In this paper, the effect of surface roughness and elastic deformation of bearing liner on the static characteristics of journal bearings are presented. A power law model is developed for the elastohydrodynamic lubrication regime. The modified Reynolds equations with elasticity equation were formulated for the elastohydrodynamic journal bearings under heavy load conditions. Multigrid and multilevel technique with Newton’s method were used to calculated the elastohydrodynamic bearing to obtain the oil film pressure profile, oil film thickness profile, load capacity, attitude angle and friction coefficient at various surface roughness parameters. The static characteristics of the rough elastohydrodynamic journal bearing were compared with that of the rough hydrodynamic journal bearings. The results show that the surface roughness and elastic deformation significantly affect the static characteristics of journal bearings under severe operating conditions.

Simulation studies on static thermal behaviour of true elliptical and orthogonally displaced non-circular journal bearing

2016 ◽  
Vol 68 (3) ◽  
pp. 349-360 ◽  
Author(s):  
Amit Singla ◽  
Amit Chauhan
Keyword(s):  
Journal Bearing ◽  
Load Capacity ◽  
Current Trend ◽  
Operating Conditions ◽  
Performance Characteristics ◽  
Film Pressure ◽  
Content Type ◽  
Oil Film ◽  
Ellipticity Ratio ◽  
Oil Film Pressure

Purpose The current trend of modern industry is to use machineries which rotate at high speed along with the capability of carrying heavy rotor loads. This paper aims at static thermal analysis of two different profiles of non-circular journal bearings – a true elliptical bearing and orthogonal bearing. Design/methodology/approach The Reynolds equation has been solved through finite difference method to compute the oil film pressure. Parabolic temperature profile approximation technique has been used to solve the energy equation and thus used for computation of various bearing performance characteristics such as thermo-hydrodynamic oil film pressure, temperature, load capacity, Sommerfeld number and power loss characteristics across the bearing. The effect of ellipticity ratio on the bearing performance characteristics has also been obtained for both the elliptical and vertical offset bearing using three different commercially available grades of oil (Hydrol 32, 68 and 100). Findings It has been observed that the thermo-hydrodynamic pressure and temperature rise of the oil film is less in orthogonal bearing as compared to the true elliptical bearing for same operating conditions. The effect of ellipticity ratio of non-circularity on bearing performance parameters have been observed to be less in case of elliptical bearing as compared to orthogonal bearing. It has been concluded that though the rise in oil film temperature is high for true elliptical bearing, but still it should be preferred over orthogonal profile under study, as it has comparably good load-carrying capacity. Originality/value The performance parametric analysis will help the designers to select such kind of non-circular journal bearing for various applications.

STATIC CHARACTERISTICS OF OFFSET 8-LOBE JOURNAL BEARINGS

Tribologia ◽  
2021 ◽  
Vol 295 (1) ◽  
pp. 39-51
Author(s):  
Stanisław Strzelecki
Keyword(s):  
Laminar Flow ◽  
Equilibrium Position ◽  
Iterative Procedure ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Diameter Ratio ◽  
Static Characteristics ◽  
Oil Film ◽  
Cooling Conditions ◽  
Grinding Machines

The 8-lobe journal bearings have found application in the bearing systems of spindles of grinding machines. The design of bearings and the large number of lobes and oil grooves assures good cooling conditions of bearing. These bearings can be manufactured as the bearings with cylindrical, non-continuous operating surfaces separated by six lubricating grooves, bearings with the pericycloidal shape of the bearing bore, and as offset journal bearing. This paper presents the results of the computation of static characteristics of an offset 8-lobe journal bearing operating under the conditions of an aligned axis of journal and bush, adiabatic oil film, and at the static equilibrium position of journal. Different values of bearing length to diameter ratio, relative clearance, and lobe relative clearance were assumed. Reynolds' energy and viscosity equations were solved by means of an iterative procedure. Adiabatic oil film, laminar flow in the bearing gap, and aligned orientation of journal in the bearing were considered.

Rayleigh Step Journal Bearing: Part 1—Compressible Fluid

1968 ◽  
Vol 90 (1) ◽  
pp. 271-280 ◽  
Author(s):  
B. J. Hamrock
Keyword(s):  
Compressible Fluid ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Load Capacity ◽  
Maximum Load ◽  
Pressure Profile ◽  
Clearance Ratio ◽  
Attitude Angle ◽  
Step Parameters ◽  
Bearing Part

A linearized PH solution to the Reynolds equation was obtained while neglecting side leakage. The analysis was divided into two parts—the step and ridge regions. The pressure profile across the step and ridge region of the various pads which are placed around the journal was obtained from the linearized PH Reynolds equation. Knowing the pressure, the load components and attitude angle were calculated. The resulting equations were found to be a function of the bearing parameters (the eccentricity and compressibility number) and the step parameters (ratio of the stepped clearance to the ridge clearance, ratio of the angle extended by the ridge to the angle extended by the pad, and number of pads placed around the journal). The maximum load capacity can be determined by numerically differentiating the load with respect to the step bearing parameters while finding where the slope is zero. A series of data was run while varying the bearing parameters. The attitude angle was calculated for the various cases which were run.

Static characteristics of misaligned multiple axial groove water-lubricated bearing in the turbulent regime

2016 ◽  
Vol 231 (3) ◽  
pp. 385-398 ◽  
Author(s):  
Ravindra Mallya ◽  
Satish B Shenoy ◽  
Raghuvir Pai
Keyword(s):  
Reynolds Number ◽  
Friction Coefficient ◽  
Carrying Capacity ◽  
Journal Bearing ◽  
Load Capacity ◽  
Turbulent Regime ◽  
Load Carrying Capacity ◽  
Static Characteristics ◽  
Load Carrying ◽  
Turbulence Effects

The static characteristics of misaligned three-axial water-lubricated journal bearing in the turbulent regime are analyzed for groove angles 36° and 18°. Ng and Pan’s turbulence model is applied to study the turbulence effects in the journal bearing. The static parameters such as load-carrying capacity, friction coefficient, and side leakage are found for different degree of misalignment (DM). The change in flow regime of the lubricant from laminar to turbulent and the increase in misalignment, improved the load capacity of the bearing. For lightly loaded bearings, the friction coefficient of the bearing increased with the increase in Reynolds number.

Rayleigh Step Journal Bearing, Part II—Incompressible Fluid

1969 ◽  
Vol 91 (4) ◽  
pp. 641-650 ◽  
Author(s):  
B. J. Hamrock ◽  
W. J. Anderson
Keyword(s):  
Theoretical Analysis ◽  
Film Thickness ◽  
Journal Bearing ◽  
Load Capacity ◽  
Maximum Load ◽  
Single Step ◽  
Thickness Ratio ◽  
Infinite Length ◽  
One Step ◽  
Bearing Part

A theoretical analysis of the pressure distribution, load, capacity, and attitude angle for a single-step concentric as well as a multistep infinite length eccentric Rayleigh step journal bearing is performed. The results from the single-step concentric analysis indicated that the maximum load capacity is obtained when the film thickness ratio is 1.7 and the ratio of the angle subtended by the ridge to the angle subtended by the pad is 0.35. The results from the infinite length eccentric analysis indicated that one step placed around the journal was optimal. For eccentricity ratios greater than or equal to 0.2 the maximum load occurred for a bearing without a step or a Sommerfeld bearing. For eccentricity ratios less than 0.2 the optimal film thickness ratio is 1.7 while there are three optimal ratios of angle subtended by the ridge to the angle subtended by the pad of 0.4, 0.45, and 0.5 depending on whether load capacity or stability or both load capacity and stability is more important in the application being considered.

The Vane Bearing—A Self-Pressurizing Journal Bearing

1975 ◽  
Vol 189 (1) ◽  
pp. 99-106 ◽  
Author(s):  
C. Ettles
Keyword(s):  
Theoretical Analysis ◽  
Journal Bearing ◽  
Load Capacity ◽  
Vane Pump ◽  
Power Requirement ◽  
Displacement Effect ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Positive Displacement ◽  
Exit Port

If the shaft of a journal bearing could be made to have a number of pressure sources which travel with the shaft, the load capacity of the oil film could be greatly enhanced. This paper describes the development of a concept in which the pressure sources arise from a positive displacement effect due to the eccentricity of the shaft within the bearing. The configuration has similarities to the rotor of a vane pump in which the entry port is open and the exit port closed. The bearing could be described as a hybrid hydrodynamic-hydrostatic bearing where the hydrostatic supply is self-contained and self-generated. A number of methods of causing this self-pressurization are discussed. A theoretical analysis shows that load (or Sommerfeld) number improvement factors in the range 3–10 are quite feasible at the expense of an increased flow and power requirement.

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