An Experimental Study on Externally Pressurized Supersonic Gas Thrust Bearings

1985 ◽  
Vol 107 (1) ◽  
pp. 122-127 ◽  
Author(s):  
Yutaka Miyake ◽  
Takehiko Inaba ◽  
Naoshige Kubo ◽  
Jun-ichi Takeoka
Keyword(s):  
Experimental Study ◽  
Flow Rate ◽  
Load Capacity ◽  
Experimental Results ◽  
Static Characteristics ◽  
Thrust Bearings ◽  
Pressure Distributions ◽  
Theoretical Predictions ◽  
New Type ◽  
Good Agreement

Externally pressurized supersonic gas thrust bearings whose generation of load capacity is substantially independent of the viscosity of working fluids, have been proposed and analyzed by the authors. This report presents the experimental results of the static characteristics of this new type of bearings. The experimental results including load capacity, stiffness, mass flow rate, and pressure distributions in the bearing clearance, generally show a good agreement with the theoretical predictions and verify the validity of this new bearing. The effect of an orifice to improve the stiffness is also examined. Some problems which should be solved to put the bearing in practical use are pointed out.

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.

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.

An Experimental Hydrodynamic Thrust Bearing Device and Its Application to the Study of a Tapered-Land Thrust Bearing

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Y. Henry ◽  
J. Bouyer ◽  
M. Fillon
Keyword(s):  
Experimental Study ◽  
Thrust Bearing ◽  
Active Surface ◽  
Friction Torque ◽  
Experimental Results ◽  
Hydrodynamic Behavior ◽  
Thrust Bearings ◽  
Surface Polishing ◽  
Pressure Peak ◽  
Good Agreement

An experimental study is presented with the main objective of understanding the hydrodynamic behavior of a tapered-land thrust bearing with fixed geometry. The experimental results were obtained using an original test rig designed at the “Institut Pprime.” Extensive instrumentation applied to the thrust bearing allows a precise evaluation of various characteristics such as the temperature, the film thickness and the friction torque. The results are in good agreement with the findings of other surveys in the literature. However, large differences between the measured parameters were observed from one pad to another. The authors demonstrate that this is due to the imperfections on the active surface, produced during machining. For a better understanding of the influence of irregularities in the flatness, the test was repeated with a thrust bearing manufactured using a high-precision surface polishing process. Experimental results with respect to the real geometry of the bearings were presented with both processes being compared. Interesting features, such as hot spots and a pressure peak, were identified on the pad at different supply temperatures and inlet pressures. This experimental study significantly advances the comprehension of the hydrodynamic behavior of tapered-land thrust bearings.

scholarly journals Experimental study of the $ \gamma p \rightarrow K^{0}\Sigma^{+}$, $ \gamma n \rightarrow K^{0} \Lambda$, and $ \gamma n \rightarrow K^{0} \Sigma^{0}$ reactions at the Mainz Microtron

2019 ◽  
Vol 55 (11) ◽  
Author(s):  
C. S. Akondi ◽  
K. Bantawa ◽  
D. M. Manley ◽  
S. Abt ◽  
P. Achenbach ◽  
...  
Keyword(s):  
Experimental Study ◽  
Cross Sections ◽  
Differential Cross ◽  
Legendre Polynomials ◽  
Neutral Kaon ◽  
Experimental Results ◽  
Differential Cross Sections ◽  
Theoretical Predictions ◽  
Photoproduction Reactions ◽  
Insight Into

Abstract.This work measured $ \mathrm{d}\sigma/\mathrm{d}\Omega$dσ/dΩ for neutral kaon photoproduction reactions from threshold up to a c.m. energy of 1855MeV, focussing specifically on the $ \gamma p\rightarrow K^0\Sigma^+$γp→K0Σ+, $ \gamma n\rightarrow K^0\Lambda$γn→K0Λ, and $ \gamma n\rightarrow K^0 \Sigma^0$γn→K0Σ0 reactions. Our results for $ \gamma n\rightarrow K^0 \Sigma^0$γn→K0Σ0 are the first-ever measurements for that reaction. These data will provide insight into the properties of $ N^{\ast}$N* resonances and, in particular, will lead to an improved knowledge about those states that couple only weakly to the $ \pi N$πN channel. Integrated cross sections were extracted by fitting the differential cross sections for each reaction as a series of Legendre polynomials and our results are compared with prior experimental results and theoretical predictions.

A Technique for the Laboratory Determination of Recirculation in Single Needle Dialysis

1993 ◽  
Vol 16 (2) ◽  
pp. 63-70 ◽  
Author(s):  
N.A. Hoenich ◽  
P.T. Smirthwaite ◽  
C. Woffindin ◽  
P. Lancaster ◽  
T.H. Frost ◽  
...  
Keyword(s):  
Experimental Data ◽  
Flow Rate ◽  
Experimental Results ◽  
New Technique ◽  
Treatment Efficiency ◽  
Single Lumen ◽  
Theoretical Predictions ◽  
Lumen Catheter ◽  
A New Technique

Recirculation is an important factor in single needle dialysis and, if high, can compromise treatment efficiency. To provide information regarding recirculation characteristics of access devices used in single needle dialysis, we have developed a new technique to characterise recirculation and have used this to measure the recirculation of a Terumo 15G fistula needle and a VasCath SC2300 single lumen catheter. The experimentally obtained results agreed well with those established clinically (8.5 ± 2.4% and 18.4 ± 3.4%). The experimental results have also demonstrated a dependence on access type, pump speeds and fistula flow rate. A comparison of experimental data with theoretical predictions showed that the latter exceeded those measured with the largest contribution being due to the experimental fistula.

Behavior of Thermal Effects and Velocity-Slip on Performance of Externally Pressurized Porous Incompressible Gas Thrust Bearing

1979 ◽  
Vol 46 (2) ◽  
pp. 465-468 ◽  
Author(s):  
V. K. Kapur ◽  
J. S. Yadav
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Effects ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Velocity Slip ◽  
Experimental Results ◽  
Slip Condition ◽  
Static Stiffness

In the present analysis, the interactions of thermal effects and velocity slip on the performance of externally pressurized porous incompressible gas thrust bearing have been studied. Numerical results for load capacity, mass flow rate, and static stiffness have been obtained and their behavior is illustrated in figures. The results for slip as well as no-slip condition have also been compared with the experimental results of Gargiulo and Gilmour [7].

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.

Experimental Study of the Plastic Interaction of Model Surface Asperities during Sliding

1968 ◽  
Vol 10 (2) ◽  
pp. 121-132 ◽  
Author(s):  
C. M. Edwards ◽  
J. Halling
Keyword(s):  
Experimental Study ◽  
Friction And Wear ◽  
Normal Force ◽  
Tangential Force ◽  
Experimental Results ◽  
Interfacial Conditions ◽  
High Adhesion ◽  
Theoretical Predictions ◽  
Very High ◽  
Low Shear

The paper describes an experimental study of the plastic interaction of triangular shaped lead model asperities deformed under conditions of plane strain. The investigation yields values of the normal and tangential force variations throughout the junction interaction and details of the plastic deformation particularly in relation to junction growth. A number of asperity interfacial conditions are considered ranging from complete adhesion to very low shear strengths achieved using p.t.f.e. strip. The experimental results are compared with an earlier theoretical solution to this problem and show reasonable agreement with the theoretical predictions. In particular it is shown that the normal force, which is usually compressive, may become tensile for conditions of high adhesion between the asperities. This leads to very high values of the macroscopic friction coefficient such as occur in hard vacuum situations. The experimental results for the various surface conditions show sufficient agreement with theoretical predictions to justify the use of this type of theoretical approach for the wider study of the friction and wear of mating surfaces.

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.

Orifice Restrictor Losses in Journal Bearings

1979 ◽  
Vol 193 (1) ◽  
pp. 47-52 ◽  
Author(s):  
E. G. Pink ◽  
K. J. Stout
Keyword(s):  
Radial Flow ◽  
Load Capacity ◽  
Journal Bearings ◽  
Experimental Results ◽  
Pressure Recovery ◽  
Pressure Profiles ◽  
Compensation Factor ◽  
Good Agreement

Details of a study concerning orifice restrictor losses in externally pressurized gas lubricated journal bearings are given. The type of compensation considered is the pocketed orifice design. The analysis presented includes the effects of pressure recovery in the pocket and entrance loss effects at inlet to the bearing film. Also, by treating the flow in the bearing film local to the pocket as radial flow, the effect of dispersion is accounted for. It is shown that good agreement exists between computed and experimental results in pressure profiles and also for load capacity up to touch-down conditions. From the analysis, the effect of the inherent compensation factor, number of orifices and pocket diameter on load capacity is discussed.

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