Analysis of the Static Characteristics of a Self-Compensation Hydrostatic Spherical Hinge

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Chundong Xu ◽  
Shuyun Jiang
Keyword(s):  
Comparative Study ◽  
Flow Rate ◽  
Power Loss ◽  
Load Capacity ◽  
The Self ◽  
Static Characteristics ◽  
Static Behavior ◽  
Large Load ◽  
Spherical Hinge

This technical brief presents a new self-compensation hydrostatic spherical hinge to provide a large load capacity. The hinge consists of an upper part with self-compensation and a lower part with orifice restrictors. A comparative study of the static behavior is conducted between the self-compensation hydrostatic spherical hinge and the hydrostatic spherical hinge with orifice restrictors, the result shows that the self-compensation hydrostatic spherical hinge has an advantage in the static behavior over the hydrostatic spherical hinge with orifice restrictors, including a much larger load capacity, a smaller flow rate, and a smaller power loss.

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.

Investigations in Hydrostatic Planar Bearings Compensated by Tapered-Spool Restrictors I: Flow Rate

2015 ◽  
Vol 32 (1) ◽  
pp. 63-69
Author(s):  
Y. Kang ◽  
H.-C. Cheng ◽  
C.-W. Lee ◽  
S.-Y. Hu
Keyword(s):  
Flow Rate ◽  
Analytical Method ◽  
Pressure Difference ◽  
Load Capacity ◽  
Design Parameters ◽  
Static Characteristics ◽  
Static Stiffness ◽  
Flow Rates ◽  
Single Action ◽  
Hydrostatic Bearing

ABSTRACTThis paper is former part of serial studies to investigate the influence of design parameters of tapered-spool type restrictors on static characteristics of hydrostatic bearing. The flow rates passing restrictors can determine the static characteristics of hydrostatic bearings. In this part an analytical method which includes formulas and solving is utilized to simulate dimensionless flow rate in both single-action and double-action tapered-spool restrictors. The numerical results illustrate the variations of flow rates with respect to the change of pressure and pressure difference, respectively. The findings give that the design parameters of tapered-spool restrictors and the useful range of recess pressure. The following part will depend on this paper results to study load capacity and static stiffness of hydrostatic bearing compensated by tapered-spool restrictor.

Analysis of Static and Dynamic Characteristic of Hydrostatic Spherical Hinge

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Chundong Xu ◽  
Shuyun Jiang
Keyword(s):  
Power Loss ◽  
Load Capacity ◽  
Dynamic Stiffness ◽  
Spherical Coordinate ◽  
Damping Coefficients ◽  
Oil Flow ◽  
New Perspective ◽  
Stiffness And Damping ◽  
Spherical Hinge ◽  
Rate Dynamic

A new hydrostatic spherical hinge is developed in this paper to provide a large load capacity. The static and dynamic Reynolds equations in spherical coordinate system for incompressible Newtonian fluid were established using the perturbation method. Finite difference method was employed to solve the load capacity, power loss, oil flow rate, dynamic stiffness, and damping coefficients. This paper provides a new perspective for analysis on the dynamic characteristics of the spherical hinge.

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.

Makna Alif dalam Puisi Zikir D. Zawawi Imron dan Sajak Alif Ahmadun Yosi Herfanda

2020 ◽  
Vol 2 (1) ◽  
pp. 52
Author(s):  
Sholeha Rosalia ◽  
Yosi Wulandari
Keyword(s):  
Comparative Study ◽  
Comparative Method ◽  
The Self ◽  
Sociology Of Literature ◽  
Self Reflection ◽  
The Public ◽  
The Creation

Alif means the first, saying the Supreme Life and is Sturdy and has the element of fire and Alif is formed from Ulfah (closeness) ta'lif (formation). With this letter Allah mementa'lif (unite) His creation with the foundation of monotheism and ma'rifah belief in appreciation of faith and monotheism. Therefore, Alif opens certain meanings and definitions of shapes and colors that are in other letters. Then be Alif as "Kiswah" (clothes) for different messages. That is a will. "IQRO" is a revelation that was first passed down to the Prophet Muhammad. Saw. Read it, which starts with the letter Alif and ends with the letter Alif. The creation of a poem is influenced by the environment and the self-reflection of a poet where according to the poet's origin, in comparing in particular Alif's poetry from the two poets. The object of this research is the poetry of Zikir by D. Zawawi Imron and Sajak Alif by Ahmadun Yosi Herfanda. This study uses a comparative method and sociology of literature. Through a comparative study of literature between the poetry of Zikir D. Zawawi Imron and Sajak Alif Ahmadun Yosi Herfanda, it is hoped that the public can know the meaning of Alif according to the poet's view. With this research, the Indonesian people can accept different views on the meaning of Alif in accordance with their respective understanding without having to look for what is right and wrong. The purpose in Alif is like a life, in the form of letters like a body, a tree that is cut to the root, from the heart is split to the seeds, then from the seeds are split so that nothing is the essence of life. So, it is clear that Alif is the most important and Supreme letter. Talking about the meaning of Alif as the first letter revealed on earth. After the letter Alif was revealed, 28 other Hijaiyah letters were born. The letter Alif is made the beginning of His book and the opening letter. Other letters are from Alif and appear on him.

scholarly journals Comparative Study of Chemosensory Dysfunction in COVID-19 in 2 Geographically Distinct Regions

2021 ◽  
pp. 014556132110001
Author(s):  
Daniel J. Lee ◽  
Daniella Daliyot ◽  
Ri Wang ◽  
Joel Lockwood ◽  
Paul Das ◽  
...  
Keyword(s):  
Comparative Study ◽  
Symptom Onset ◽  
Subgroup Analysis ◽  
Primary Outcome ◽  
Cross Sectional Study ◽  
The Self ◽  
Sectional Study ◽  
Cross Sectional ◽  
Specific Data ◽  
Geographical Regions

Objective: To directly compare the prevalence of chemosensory dysfunction (smell and taste) in geographically distinct regions with the same questionnaires. Methods: A cross-sectional study was performed to evaluate the self-reported symptoms among adults (older than 18 years) who underwent COVID-19 testing at an ambulatory assessment center in Canada and at a hospital in Israel between March 16, 2020, and August 19, 2020. The primary outcome was the prevalence of self-reported chemosensory dysfunction (anosmia/hypomsia and dysgeusia/ageusia). Subgroup analysis was performed to evaluate the prevalence of chemosensory deficits among the outpatients. Results: We identified a total of 350 COVID-19–positive patients (138 Canadians and 212 Israelis). The overall prevalence of chemosensory dysfunction was 47.1%. There was a higher proportion of chemosensory deficits among Canadians compared to Israelis (66.7% vs 34.4%, P < .01). A subgroup analysis for outpatients (never hospitalized) still identified a higher prevalence of chemosensory dysfunction among Canadians compared to Israelis (68.2% vs 36.1%, P < 0.01). A majority of patients recovered their sense of smell after 4 weeks of symptom onset. Conclusion: Although the prevalence of chemosensory deficit in COVID-19 was found to be similar to previously published reports, the prevalence can vary significantly across different geographical regions. Therefore, it is important to obtain regionally specific data so that the symptom of anosmia/dysgeusia can be used as a guide for screening for the clinical diagnosis of COVID-19.

Performance of Hydrostatic Spherical Gas Gyro Bearings

1976 ◽  
Vol 98 (1) ◽  
pp. 111-116 ◽  
Author(s):  
A. Gu ◽  
L. Cziglenyi
Keyword(s):  
Numerical Solution ◽  
Flow Rate ◽  
Gas Flow ◽  
Load Capacity ◽  
Performance Data ◽  
Drag Torque ◽  
Fixed Bearing ◽  
Gas Flow Rate

Analysis and method of numerical solution for evaluating the performance of hydrostatic spherical gas gyro bearings at any gimbal angle and at any eccentricity have been developed. Performance data on load capacity, gas flow rate, drag torque, and error torque over some ranges of gimbal angle and eccentricity are presented. Comparison has been made between the equatorially vented and nonvented bearings of fixed bearing angles.

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.

Influence of Diameter and Number of Orifice on Static Characteristics of Radial-Thrust Aerostatic Bearing

2012 ◽  
Vol 497 ◽  
pp. 78-82
Author(s):  
Fei Hu Zhang ◽  
Sheng Fei Wang ◽  
Qiang Zhang ◽  
Peng Qiang Fu
Keyword(s):  
Machine Tool ◽  
Fluid Dynamic ◽  
Load Capacity ◽  
Large Diameter ◽  
Orifice Diameter ◽  
Static Characteristics ◽  
Aerostatic Bearing ◽  
Supporting System ◽  
Manufacturing Technologies ◽  
Radial Thrust

The working performance of the spindle system is the most important factor to embody the overall performance of the machine tool. To ensure the advanced capabilities, besides the high-precision manufacturing technologies, it is mainly depending on the bearing module and the forces on the spindle. In this paper, a new strategy of the vertical spindle supporting system is presented to meet the high stiffness requirement for the aerostatic bearing. Based on the computational fluid dynamics and finite volume method, a fluid dynamic model and structure model of the large diameter incorporate radial-thrust aerostatic bearing is developed and simulated to find out the pressure distribution laws of the spindle supporting system. The grid subdivision in the direction of film thickness is paid more attentions when establishing the grid of the whole gas film. Simulation results show that this special structure of bearing module can supply enough load capacity and stiffness for the machine tool. The results also indicate that the static characteristics of the bearing are improved as the supply pressure increases and as the supply orifice diameter decreases.

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