Analysis of Carrying Capacity and Friction Torque of Friction Pair Fluid-Film for High Parameter Bellows Mechanical Seal

2013 ◽  
Vol 455 ◽  
pp. 207-211
Author(s):  
Mutellip Ahmat ◽  
Zhi Wei Niu ◽  
Guzaiayi Abudoumijiti
Keyword(s):  
Carrying Capacity ◽  
High Speed ◽  
Influence Factor ◽  
Friction Pair ◽  
Scientific Basis ◽  
Friction Torque ◽  
Fluid Film ◽  
Mechanical Seal ◽  
Mechanical Seals ◽  
The Relationship

The friction pair for bellows mechanical seal as a friction element is one of the key components for it. In this research, by based on the computational fluid dynamics (CFD) numerical theory, using the Fluent software, corresponding model and parameters, the fluid-film between the clearance of the sealing ring friction pair for the bellows mechanical seal under such the high-temperature, high-pressure, high-speed as complex working conditions is numerically simulated, the relationship between the carrying-capacity of the fluid-film and the temperature, the viscosity of the fluid-film, the relationship between friction torque of the fluid-film and the speed, viscosity of the fluid-film, the influence factor of leakage are obtained. The researching results provide the scientific basis for the optimization designing of the high parameter bellows mechanical seals.

Analysis of the Pressure and Carrying Capacity of the Friction Pair Fluid-Film for the High Parameter Bellows Mechanical Seal

2012 ◽  
Vol 522 ◽  
pp. 441-446
Author(s):  
Qiang Gao ◽  
Mutellip Ahmat ◽  
Li Chao Ren ◽  
Jing Luo
Keyword(s):  
Carrying Capacity ◽  
High Speed ◽  
Friction Pair ◽  
Scientific Basis ◽  
Fluid Film ◽  
Mechanical Seal ◽  
Mechanical Seals ◽  
Numerical Theory ◽  
Sealing Ring ◽  
Relationship Of

In this research, by based on the computational fluid dynamics (CFD) numerical theory, using the Standard-Turbulence model and the Standard-Wall function, the fluid-film between the clearance of the sealing ring friction pair for the bellows mechanical seal under such the high-temperature, high-pressure, high-speed as complex working conditions was numerically simulated, the pressure fluid and the relationship of the carrying-capacity of the fluid-film between the pressure inlet of seal cavity and the width of the fluid-film, and the results of the numerical analysis was compared with the theoretical value. The researching results provide the scientific basis for the optimization designing of the high parameter bellows mechanical seals.

Optimum Design of Flat End Face Mechanical Seal Based on Coupling Analysis

2010 ◽  
Vol 37-38 ◽  
pp. 819-822 ◽  
Author(s):  
Jian Feng Zhou ◽  
Bo Qin Gu ◽  
Chun Lei Shao
Keyword(s):  
Optimum Design ◽  
Thermal Deformation ◽  
Coupling Effect ◽  
Design Method ◽  
Fluid Film ◽  
Outer Side ◽  
Mechanical Seal ◽  
Mechanical Seals ◽  
Friction Heat ◽  
Bearing Force

The flat end face mechanical seals are widely used in shaft sealing at moderate rotational speed. The thermal deformation of the rotating and stationary rings initiated by friction heat of fluid film should be primarily considered in the design of mechanical seal. In consideration of the coupling effect among the thermal deformation of sealing rings, the fluid flow in the gap composed by end faces of sealing rings and the heat transfer from fluid film to sealing rings, the optimum design method for flat end face mechanical seal is established. The end faces are fabricated to form a divergent gap at the inner side of the sealing rings, and a convergent gap will occur at the outer side and a parallel gap will be obtained at where the original divergent gap is due to the thermal deformation. After optimization, the leakage rate can be reduced while the bearing force of fluid film is still large enough to keep the fluid lubrication of the end faces.

Theoretical and Experimental Research on Tapping of GH4169 and TC4 with Modified-Tooth Taps

2008 ◽  
Vol 375-376 ◽  
pp. 221-225
Author(s):  
Yan Li Tang ◽  
Rong Di Han ◽  
Jia Bin Ju
Keyword(s):  
High Speed ◽  
Cone Angle ◽  
High Speed Steel ◽  
Friction Torque ◽  
Theoretical Principle ◽  
Outer Diameter ◽  
Machined Surface ◽  
Frictional Wear ◽  
Fundamental Reason ◽  
The Relationship

Based on the theoretical principle of tapping formation and simulation with modified-tooth tap, the relationship among the different geometric parameters of the tap was further analyzed. A series of modified-tooth taps and standard ones with a cutting cone angle of 7°30´and a outer diameter of M6, which were made from high-speed steel W9, were taken to do the comparative tapping test on nickel-based high-temperature alloy GH4169, titanium alloy TC4 and 45 steel. The test results indicated that the leading cause of difficult tapping in GH4169 and TC4 was the largeness of their friction torques which were about 35 % and 62 % of tapping torque respectively, where the frictional wear was a fundamental reason for tough tapping GH4169 and the spring back of machined surface for TC4.The obvious decreases of friction torque with the modified-tooth tap approximately 70% and 50% respectively for GH4169 and TC4 were attributed to its unique tapping formation principle of generating broaching but no remarkable effects on 45 steel in comparison with standard tap.

Calculation of Carrying Capacity at High-Speed Railway Stations Based on Route Selection

2015 ◽  
Vol 744-746 ◽  
pp. 1786-1791
Author(s):  
Qian Rui Zhao ◽  
Qi Zhang ◽  
Pei Liu
Keyword(s):  
Carrying Capacity ◽  
High Speed ◽  
Operation Time ◽  
Route Selection ◽  
High Speed Railway ◽  
Railway Stations ◽  
Selection Scheme ◽  
Capacity Calculation ◽  
The Relationship

Carrying capacity calculation at high-speed railway stations is closely related to the trains with different types and arriving rules. Traditional method is not feasible to calculate and evaluate carrying capacity at high-speed railway stations efficiently and accurately. Therefore, a method to calculate carrying capacity at high-speed railway stations was presented by establishing a route selection optimization model and designing corresponding algorithm. In the method, the integration concept of calculating carrying capacity was introduced by establishing the relationship between receiving dispatching route and arrival-departure track. An approach was provided to the solution of route selection scheme and calculating carrying capacity at high-speed railway stations efficiently and accurately by considering the differences of trains with different operation modes and operation time. Case study of Jinan West railway station verifies the feasibility of the method. The presented method can provide a technical support for calculating and evaluating carrying capacity at high-speed railway stations in different scenarios.

scholarly journals Research on the Dynamic Characteristics of Mechanical Seal under Different Extrusion Fault Degrees

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1057
Author(s):  
Yin Luo ◽  
Yakun Fan ◽  
Yuejiang Han ◽  
Weqi Zhang ◽  
Emmanuel Acheaw
Keyword(s):  
Film Thickness ◽  
Dynamic Characteristics ◽  
Fluid Film ◽  
Mechanical Seal ◽  
Mechanical Seals ◽  
Rotating Speed ◽  
Analysis Process ◽  
Fluid Film Thickness ◽  
Object Of Study ◽  
Fault Mechanism

In order to explore the dynamic characteristics of the mechanical seal under different fault degrees, this paper selected the upstream pumping mechanical seal as the object of study. The research established the rotating ring-fluid film-stationary ring 3D model, which was built to analyze the fault mechanism. To study extrusion fault mechanism and characteristics, different dynamic parameters were used in the analysis process. Theoretical analysis, numerical simulation, and comparison were conducted to study the relationship between the fault degree and dynamic characteristics. It is the first time to research the dynamic characteristics of mechanical seals in the specific extrusion fault. This paper proved feasibility and effectiveness of the new analysis method. The fluid film thickness and dynamic characteristics could reflect the degree of the extrusion fault. Results show that the fluid film pressure fluctuation tends to be more intensive under the serious extrusion fault condition. The extrusion fault is more likely to occur when the fluid film thickness is too large or too small. Results illustrate the opening force is affected with the fluid film lubrication status and seal extrusion fault degrees. The fluid film stiffness would not always increase with the rotating speed growth. The seal fault would occur with the increasing of rotating speeds, and the leakage growth fluctuations could reflect the fault degree.

Relationship Between Vibrations and Mechanical Seal Failures in Centrifugal Pumps

2005 ◽  
Author(s):  
David B. Stefanko ◽  
Robert A. Leishear
Keyword(s):  
Industrial Applications ◽  
The Other ◽  
Fluid Film ◽  
Operating Speed ◽  
Mechanical Seal ◽  
Mechanical Seals ◽  
Centrifugal Pumps ◽  
Radial Vibrations ◽  
The Common ◽  
Bearing Design

A reduction of radial vibrations in mechanical seals increases the life of the seals in centrifugal pumps. Mechanical seals consist of two smooth seal faces. One face is stationary with respect to the pump. The other rotates. Between the faces a fluid film evaporates as the fluid moves radially. Ideally, the film evaporates as it reaches the outer surface of the seal faces, thereby preventing leakage from the pump and effectively lubricating the two surfaces. Relative vibrations between the two surfaces affect the fluid film, damage the faces, and decrease the life of the seals. In a series of industrial applications, different techniques were used to minimize vibration, and the life of the seals was shown to significantly increase. The operating speed was controlled in one case, the bearing design was replaced in another case, and the stiffness of the pump was altered in still another case. The common corrective action in each case was a reduction in vibration.

Predictions for Non-Contacting Mechanical Face Seal Vibration With External Excitation From Pump Vibration: Part II — Flexibly Mounted Rotor

2018 ◽  
Author(s):  
Clay S. Norrbin ◽  
Dara W. Childs
Keyword(s):  
Excitation Frequency ◽  
Harmonic Excitation ◽  
Fluid Film ◽  
Axial Distance ◽  
Mechanical Seal ◽  
Seal Ring ◽  
Mechanical Seals ◽  
Running Speed ◽  
Frequency Dependent ◽  
Frequency Independent

Stability and response predictions are presented for a Flexibly Mounted Rotor (FMR) mechanical seal ring using the model developed by Childs in 2018. The seal ring is excited by lateral/pitch vibration from the rotor/housing. The model includes a frequency dependent stiffness and damping model for the O-ring and a frequency independent model for the fluid film. The dynamic coefficients are speed and frequency dependent. The mechanical seal is modeled after a typical FMR mechanical seal. Parameters for radius, fluid film clearance, and O-Ring axial distances are varied. The axial distance between the O-Ring and seal ring inertia center doz is found to couple lateral rotor motion and seal ring pitch vibration. The predictions show a dependency on both excitation frequency and running speed. The analyzed FMR has a critical region with high transmissibility in a region around a speed and excitation frequency of 70 kRPM. Another region of high transmissibility is predicted to be with sub-harmonic excitation frequency. The FMR seal ring also has an unstable region that is sub-harmonic of 1% running speed. Running back on the HQ curve for a pump causes broadband sub-harmonic excitaiton, which can cause rub failures for FMR mechanical seals.

Numerical Analysis the Tibological Performance of a Laser Surface Textured Mechanical Seal

2011 ◽  
Vol 464 ◽  
pp. 518-523
Author(s):  
Yong Hong Fu ◽  
Jing Hu Ji ◽  
Xi Jun Hua ◽  
Qin Sheng Bi
Keyword(s):  
Numerical Study ◽  
Tribological Performance ◽  
Friction Torque ◽  
Diameter Ratio ◽  
Laser Surface ◽  
Hydrodynamic Effect ◽  
Geometrical Parameters ◽  
Mechanical Seal ◽  
Mechanical Seals ◽  
Area Density

This paper presents a numerical study of the effects of surface structure geometrical parameters on the tribological performance of a laser surface textured mechanical seal. Seal performance such as seal clearance which is corresponding to hydrodynamic effect and friction torque is calculated for a range of sealed pressures, dimples area density and dimple depth over dimple diameter ratio. The results indicated that laser surface textured mechanical seals substantially improve the tribological performance in the lower sealed pressure than in high pressure. Area density of dimples has little effect on the tribological performance, however, dimple depth over dimple diameter ratio has significant effect on the tribological performance.

scholarly journals Relationship Between Vibrations and Mechanical Seal Life in Centrifugal Pumps

2007 ◽  
Author(s):  
Robert A. Leishear ◽  
David B. Stefanko
Keyword(s):  
Crack Growth ◽  
Fatigue Damage ◽  
The Other ◽  
Fluid Film ◽  
Time To Failure ◽  
Mechanical Seal ◽  
Mechanical Seals ◽  
Centrifugal Pumps ◽  
Vibration Data ◽  
Cyclic Stresses

A reduction of vibrations in mechanical seals increases the life of the seals in centrifugal pumps by minimizing fatigue damage. Mechanical seals consist of two smooth seal faces. One face is stationary with respect to the pump. The other rotates. Between the faces a fluid film evaporates as the fluid moves radially outward across the seal face. Ideally, the film evaporates as it reaches the outer surface of the seal faces, thereby preventing leakage from the pump and effectively lubricating the two surfaces. Relative vibrations between the two surfaces affect the fluid film and lead to stresses on the seal faces, which lead to fatigue damage. As the fluid film breaks down, impacts between the two seal faces create tensile stresses on the faces, which cycle at the speed of the motor rotation. These cyclic stresses provide the mechanism leading to fatigue crack growth. The magnitude of the stress is directly related to the rate of crack growth and time to failure of a seal. Related to the stress magnitude, vibration data is related to the life of mechanical seals in pumps.

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