scholarly journals Description of the Pumping Rate of Shaft Counterfaces in the Sealing System Radial Lip Seal Using the 3D Parameters of ISO 25178

2016 ◽  
Vol 11 (2) ◽  
pp. 69-74
Author(s):  
Cornelius Fehrenbacher ◽  
Lothar Hoerl ◽  
Frank Bauer ◽  
Werner Haas
Keyword(s):  
Pumping Rate ◽  
Lip Seal ◽  
Iso 25178

Hydrodynamic Analysis of the Flow in a Rotary Lip Seal Using Flow Factors

2004 ◽  
Vol 126 (1) ◽  
pp. 156-161 ◽  
Author(s):  
Richard F. Salant ◽  
Ann H. Rocke
Keyword(s):  
Flow Field ◽  
Pressure Distribution ◽  
Reynolds Equation ◽  
Present Approach ◽  
Operating Parameters ◽  
Pumping Rate ◽  
Hydrodynamic Analysis ◽  
Lip Seal ◽  
Lubricating Film ◽  
Computationally Intensive

The flow field in the lubricating film of a rotary lip seal is analyzed numerically by solving the Reynolds equation with flow factors. The behavior of such a flow field is dominated by the asperities on the lip surface. Since previous analyses treated those asperities deterministically, they required very large computation times. The present approach is much less computationally intensive because the asperities are treated statistically. Since cavitation and asperity orientation play important roles, these are taken into account in the computation of the flow factors. Results of the analysis show how the operating parameters of the seal and the characteristics of the asperities affect such seal characteristics as the pressure distribution in the film, the pumping rate and the load support.

scholarly journals Numerical Simulation and Experimental Study on Sealing Performance and Frictional Property of Rotary Lip Seal

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Huifang Dong ◽  
Jian Hu
Keyword(s):  
Friction Pair ◽  
Solution Process ◽  
Friction Torque ◽  
Contact Load ◽  
Necessary Condition ◽  
Bench Test ◽  
Frictional Property ◽  
Pumping Rate ◽  
Lip Seal ◽  
Sealing Performance

The hydrodynamic theoretical lubrication model of the friction pair between the rotary shaft and the lip seal under the state of full film lubrication was established in this paper. The Reynolds equation was solved by using the finite difference method, and the influence of the viscosity-temperature characteristics of the lubricant was taken into account in the solution process. The distribution of the film thickness and the hydrodynamic pressure in the sealing area was obtained. At the same time, the bench test was carried out and the correctness of the model was verified by comparing the simulation results and test results of reverse pumping rate and friction torque under different rotational speed of the shaft. The microasperity of the lip surface is a necessary condition for achieving the sealing effect. Therefore, the influences of the contact load of the seal and the root mean square deviation of the lip surface on the sealing performance and frictional property were analyzed by using the theoretical model. The analysis results show that the sealing performance and frictional property can be changed by changing the contact load and surface roughness of the lip, but a single increase in the influence of a certain factor cannot achieve good results, and comprehensive consideration is required in product design.

Elastohydrodynamic Analysis of Reverse Pumping in Rotary Lip Seals With Microundulations

1994 ◽  
Vol 116 (1) ◽  
pp. 56-62 ◽  
Author(s):  
R. F. Salant ◽  
A. L. Flaherty
Keyword(s):  
Fluid Mechanics ◽  
High Pressures ◽  
Elastic Behavior ◽  
Pumping Rate ◽  
Dynamic Conditions ◽  
Lip Seal ◽  
Lubricating Film ◽  
Lip Seals ◽  
Reverse Pumping

An elastohydrodynamic analysis of a rotary lip seal containing microundulations, incorporating both the fluid mechanics of the lubricating film and the elastic behavior of the lip, has been performed numerically. The results indicate that, under dynamic conditions, the undulation pattern deforms such that it produces reverse pumping. The reverse pumping rate is substantial, and overwhelms the natural leakage induced by the sealed pressure, thereby preventing leakage through the seal. The results also show that the undulations hydrodynamically generate sufficiently high pressures, within the film, to provide load support and maintain the integrity of the film.

Soft Elastohydrodynamic Analysis of Radial Lip Seals With Deterministic Microasperities on the Shaft

2007 ◽  
Vol 129 (4) ◽  
pp. 851-859 ◽  
Author(s):  
Philip C. Hadinata ◽  
Lyndon Scott Stephens
Keyword(s):  
Friction Coefficient ◽  
Load Capacity ◽  
Asperity Height ◽  
Pumping Rate ◽  
Simultaneous Reduction ◽  
Lip Seal ◽  
Lip Seals ◽  
Lubrication Characteristics ◽  
Triangular Design ◽  
Reverse Pumping

A numerical analysis is conducted to investigate the elastohydrodynamic effect of deterministic microasperities on the shaft of a lip seal. Various geometries of microasperities (triangular, square, hexagonal, and circular) are put into a 100×100μm2 unit cell and are investigated using Reynolds equation. For each shape, the area fraction of the microasperity is varied between 0.2 and 0.8, and the asperity height is varied between 0.3μm and 5μm. The calculation for load capacity and friction coefficient indicates that there are values for asperity height, where the load capacity and friction coefficient are optimized. These optimum heights were reached at 1–3μm. Although the lip seal surface is considered to be smooth, reverse pumping can still be obtained using an oriented triangular design. The Couette flow rate for this asperity showed lubricant is reverted back toward the seal side 2.6 times more than using a conventional lip seal. The addition of microasperities to the shaft surface shows significant improvement in lubrication characteristics for the lip seal in the form of a simultaneous reduction in friction coefficient and increase in the reverse pumping rate.

Influence of Additives in Synthetic Oils on Radial Lip Seals

2011 ◽  
Author(s):  
Mathias Klaiber ◽  
Werner Haas
Keyword(s):  
Friction Torque ◽  
Operating Conditions ◽  
Functional Tests ◽  
Dynamic Tests ◽  
Pumping Rate ◽  
Base Oil ◽  
Lip Seal ◽  
Lip Seals ◽  
Elastomeric Materials ◽  
Points Of View

This project has been initiated in order to get a general basic understanding about the influence of additives onto elastomeric lip seal systems. It is necessary to determine the behavior with single additive base oil compounds. Two different synthetic base oils, Polyglycol (PG) and Polyalphaolefin (PAO), are used. Thus 19 different single additive base oil compounds have been reviewed. Two different elastomeric materials NBR and FPM have been taken for all the tests. In several dynamic tests the influences on the sealing systems have been investigated. These included tests for 24 hours to measure the friction torque and tests for 10 hours to measure the pumping rate. Furthermore, the operating conditions during 96 hours functional tests have been determined. A concluding view onto the compatibility, respectively the incompatibility, of the additives in these different points of view will be given.

Elastohydrodynamic Analysis of the Sealing Performance of Rotary Shaft Helix Lip Seals—Part 1

1998 ◽  
Vol 120 (3) ◽  
pp. 476-481 ◽  
Author(s):  
Lou Liming ◽  
Kazutoshi Yamamoto ◽  
Ken Ikeuchi
Keyword(s):  
Analytical Method ◽  
Hydrodynamic Lubrication ◽  
Operating Conditions ◽  
Experimental Results ◽  
Radial Load ◽  
Pumping Rate ◽  
Lip Seal ◽  
Sealing Performance ◽  
Lip Seals

Based upon EHD theory, the sealing performance of a rotary shaft helix lip seal has been analyzed numerically using a complete hydrodynamic lubrication model. In order to verify the analytical method, several experiments are carried out under different operating conditions. After verification by the experimental results, the analytical method is used to calculate the sealing limit and the optimum seal radial load. The effects of the boundary pressure of sump side upon the pumping rate of a seal are discussed.

Thermal Elastohydrodynamic Model of a Radial Lip Seal—Part I: Analysis and Base Results

1999 ◽  
Vol 121 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Kevin Day ◽  
Richard F. Salant
Keyword(s):  
Cross Sections ◽  
Thickness Distribution ◽  
Temperature Dependent ◽  
Pumping Rate ◽  
Lip Seal ◽  
Lubricating Film ◽  
Model Predictions ◽  
Dependent Model ◽  
Temperature Dependent Model ◽  
Shaft Surface

A numerical thermal elastohydrodynamic model of a radial lip seal, with a flooded air side, has been constructed. The shaft surface is modeled as perfectly smooth, while the lip microgeometry is modeled as a uniform distribution of asperities with initially circular cross-sections. The asperities can deform circumferentially as the bulk lip material shears. Both the viscosity of the fluid and the elastic modulus of the lip are temperature dependent. Model predictions include the pressure distribution in the lubricating film under the lip, the film thickness distribution, the cavitation distribution, the pumping rate, and the lip temperature distribution.

scholarly journals The Effect of Wear on the Performance of a Rotary Lip Seal

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Fei Guo ◽  
Xiaohong Jia ◽  
Wang Longke ◽  
Richard F. Salant ◽  
Yuming Wang
Keyword(s):  
Theoretical Analysis ◽  
Experimental Verification ◽  
Experimental Measurement ◽  
Friction Torque ◽  
Measuring Instrument ◽  
Optical Interferometer ◽  
Pumping Rate ◽  
Lip Seal ◽  
Surface Microtopography ◽  
Sealing Zone

Theoretical analysis, combined with experimental verification, is used to study the effect of wear on the performance of a rotary lip seal as characterized by the pumping rate and friction torque. The performance of a rotary lip seal is determined by the sealing lip surface microscopic characteristics and contact characteristics at the sealing zone. The variation of the contact characteristics with wear has been established based on the variation of the sealing lip profiles measured by using a trilinear coordinate measuring instrument. The impression method is used to copy the lip surface microtopography at different wear times and then an optical interferometer is used to measure the impression surface microtopography to obtain the variation of roughness with wear. The variations of the roughness, contact characteristics, and approximate contact temperature with wear are inserted into a mixed lubrication model to obtain the variations of the pumping rate and friction torque. A comparison of the simulated results with those from experimental measurement verifies the validity of the theoretical analysis.

Numerical Study of a Rotary Lip Seal With a Quasi-Random Sealing Surface

2000 ◽  
Vol 123 (3) ◽  
pp. 517-524 ◽  
Author(s):  
Fanghui Shi ◽  
Richard F. Salant
Keyword(s):  
Friction Coefficient ◽  
Physical Mechanism ◽  
Periodic Structures ◽  
Numerical Study ◽  
Thickness Distribution ◽  
Operating Characteristics ◽  
Pumping Rate ◽  
Lip Seal ◽  
Pressure Distributions ◽  
Reverse Pumping

In all previous numerical simulations of the rotary lip seal, the sealing surface was modeled by regular periodic structures. In the present study, a more realistic quasirandom surface is used. A mixed elastohydrodynamic analysis is used to generate predictions of such seal operating characteristics as friction coefficient, reverse pumping rate, film thickness distribution, hydrodynamic and contact pressure distributions, contact area, and cavitation area. The results are in qualitative agreement with previous experimental observations. In the course of the simulations, a new physical mechanism of reverse pumping has been identified.

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