Lip Seals

Keyword(s):  
Wear ◽  
2021 ◽  
pp. 203674
Author(s):  
Jeremias Grün ◽  
Simon Feldmeth ◽  
Frank Bauer

2019 ◽  
Vol 72 (5) ◽  
pp. 557-565
Author(s):  
Dilek Bulut ◽  
Tatjana Krups ◽  
Gerhard Poll ◽  
Ulrich Giese

Purpose Elastomer seals are used in many applications. They are exposed to lubricants and additives at elevated temperatures, as well as mechanical stresses. They can only provide good sealing function when they have resistance to those factors. There are many elastomer-lubricant compatibility tests based on DIN ISO 1817 in industry. However, they are insufficient and costly. Correlations between the tests and the applications are inadequate. The purpose of this study is investigating lubricant compatibility of fluoroelastomers (FKM) seals in polyethylene-glycol (PG)- and polyalphaolefin (PAO)- based synthetic oils and developing a methodology to predict seal service life. Design/methodology/approach A new compatibility test which is more sufficient in terms of time and cost was developed and compared with a standard test, currently used in industry. Compatibility of FKM radial lip seals with PG- and PAO-based synthetic oils with different additives was investigated chemically and dynamically. Failure mechanisms were examined. Findings The new method and the Freudenberg Flender Test FB 73 11 008 showed similar results concerning damages and similar tendencies regarding wear. The additive imidazole derivative was the most critical. Static tests give indications of possible chemically active additives, but alone they are insufficient to simulate the dynamic applications. Originality/value The paper describes a new method to investigate elastomer-lubricant compatibility and gives first results with a variety of lubricants.


1987 ◽  
Vol 60 (3) ◽  
pp. 381-416 ◽  
Author(s):  
B. S. Nau

Abstract The understanding of the engineering fundamentals of rubber seals of all the various types has been developing gradually over the past two or three decades, but there is still much to understand, Tables V–VII summarize the state of the art. In the case of rubber-based gaskets, the field of high-temperature applications has scarcely been touched, although there are plans to initiate work in this area both in the U.S.A. at PVRC, and in the U.K., at BHRA. In the case of reciprocating rubber seals, a broad basis of theory and experiment has been developed, yet it still is not possible to design such a seal from first principles. Indeed, in a comparative series of experiments run recently on seals from a single batch, tested in different laboratories round the world to the same test procedure, under the aegis of an ISO working party, a very wide range of values was reported for leakage and friction. The explanation for this has still to be ascertained. In the case of rotary lip seals, theories and supporting evidence have been brought forward to support alternative hypotheses for lubrication and sealing mechanisms. None can be said to have become generally accepted, and it remains to crystallize a unified theory.


1976 ◽  
Vol 19 (3) ◽  
pp. 181-186 ◽  
Author(s):  
L. A. Horve

1997 ◽  
Vol 30 (2) ◽  
pp. 113-119 ◽  
Author(s):  
Chung Kyun Kim ◽  
Woo Jeon Shim

2021 ◽  
Vol 68 (3-4) ◽  
pp. 5-12
Author(s):  
Simon Feldmeth ◽  
Mario Stoll ◽  
Frank Bauer

The radial load of a radial lip seal indicates how strongly the sealing lip is pressed on the shaft. The radial load significantly affects the function of the seal. The German standard DIN 3761-9 describes the measurement of the radial load according to the split-shaft method but leaves room for interpretation. During the revision of the standard, a parameter study was conducted at the University of Stuttgart. This study analyses the influence of the measurement device, the mandrels and the measuring procedure on the results. Based on the study results, recommendations are derived and summarized in a best-practice guideline, which should enable an appropriate and reproducible measurement of the radial load.


2019 ◽  
pp. 101-110
Author(s):  
Heinz K. Müller ◽  
Bernard S. Nau
Keyword(s):  

2021 ◽  
Author(s):  
◽  
Nick Thompson

<p>Despite advancements in safety technology, underground mining disasters kill hundreds of people each year. Typically after a disaster, a manned response team will enter the hazardous mine to ascertain its condition and rescue any survivors. A robotic entry platform could significantly reduce the risk to the response teams and the time taken to recover any survivors. However, existing mine search and rescue robots have had limited success in past disasters. Two primary aspects caused the failure of the existing platforms; poor rough terrain ability and lack of ingress protection for the harsh mine environment.  HADES, a novel underground mine reconnaissance robot is developed to address these issues. A lightweight yet robust chassis is manufactured from fibreglass. To allow HADES to operate in the potentially explosive atmosphere, the chassis is protected with a positive pressure gas system, designed to meet the ANZ60079.29 standard. This chassis is sealed against the mine environment with a series of O-rings and lip seals. Whegs are used as the primary locomotion method and are driven with a planetary gearbox and a brushless DC motor. To further improve a rough terrain capability of the locomotion system the rear arm of the chassis is mounted on an actuated pivot, increasing the rough terrain capability of HADES.  To ensure the operator can successfully assess and navigate the mine, HADES carries a comprehensive set of environmental and navigation sensors. The internal electronics and locomotion systems are powered with six Li-Po batteries that achieve an operating time of six hours and an expected range of 25 km.  HADES is 780x800x400 mm and is mostly sealed to the IP68 standard. The locomotion system is robust and can traverse the majority of the terrain expected in an underground mine. Loss of traction is the only problem encountered with the Wheg design. However, this can be easily fixed by changing the tip shape of the Wheg.</p>


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