Merkle, Lukas ; Grün, Jeremias ; Baumann, Matthias ; Bauer, Frank: Sealing Systems under Starved Lubrication Conditions. In: International Sealing Conference : Fachverband Fluidtechnik im VDMA e.V., 2022. — ISBN 978-3-8163-0756-3, S. 561–567 — 735
Zusammenfassung
Various operating conditions can cause sealing systems to be insufficiently supplied with oil, resulting in starved lubrication. This paper deals with the experimental investigation of starved
lubrication operating conditions. For this purpose, the test rig configuration used is introduced. The influence of starved lubrication on 3 different sealing systems was investigated. In addition to a standard elastomeric rotary shaft seal, a multi-lip initially grease-filled elastomeric rotary shaft seal and a PTFE sleeve with circumferential grooves were employed. The results show that the standard rotary shaft seal is unsuitable for the investigated starved lubrication conditions. The other two sealing systems performed better in comparison and are suitable for operation with a starved oil supply, at least for short durations.Lukas, Merkle ; Baumann, Matthias ; Bauer, Frank: Rotary Shaft Seals: Correlation of Wear Formation at the Sealing Edge and Shaft under Various Operating Conditions. In: Tribology Transactions. (2022), S. 1–15 — 720 (peer-review)
Zusammenfassung
Elastomeric rotary shaft seals are a common seal type for various industrial applications. They are comparably cheap and easy to use and offer an overall good performance. But the wear behavior of these sealing systems is not fully understood and not predictable so far. If a lip seal fails, it causes high maintenance costs and environmental damage. In this article, various tribological conditions are considered. For this purpose, the sealing systems are tested with multiple operating conditions relevant to practice. Three test series are conducted with rotary shaft seals BAUM5X7 75FKM585 on plunge ground shafts. The tests are carried out with two different circumferential velocities of the shaft (4.2 and 10 m/s), three different oil sump temperatures (40, 80, and 120 °C), two different lubricant types (FVA 3 and PG 3), and five different test durations (between 100 and 625 h). For a complete acquisition of the system condition, all shaft surfaces are measured in 2D and 3D before and after the test runs and the wear of the sealing edges is evaluated with a recently developed laser line triangulation method on the complete circumference of the sealing rings. Results show large amounts of wear, depending significantly on the operating conditions. A strong correlation of the wear effects in the tribocontact area of the sealing system becomes evident. This article helps to understand and avoid critical operating conditions concerning abrasive wear.Baumann, Matthias ; Merkle, Lukas ; Bauer, Frank: Opportunities and Applications for Artificial Intelligence in Sealing Technology. In: 23rd International Colloquium Tribology : expert-Verlag, 2022. — ISBN 978-3-8169-3547-6, S. 471–473 — 697
Merkle, Lukas ; Baumann, Matthias ; Bauer, Frank: Wear on Rotary Shaft Seals: Tribological Correlation Between Wear at Sealing Edge and Wear of Shaft. In: 76th STLE Annual Meeting & Exhibition, Orlando, Florida (USA), 15.05-19.05.2022, 2022 — 705 (presentation)
Zusammenfassung
Elastomeric rotary shaft seals are a common seal type for automotive and industrial applications. The wear mechanism of these sealing systems is not fully understood and not predictable so far. If a lip seal fails, it causes high maintenance costs and environmental damage. In order to investigate the wear mechanism, an empirical test series is conducted with shaft seals on plunge ground shafts. Various tribological conditions are considered, including operating conditions relevant to practice. For a complete acquisition of the system condition, all shaft surfaces are measured 2- and 3-dimensional before and after the test runs. The wear of the sealing edges is evaluated with a recently developed laser line triangulation method on the complete circumference of the sealing rings. Results show large amounts of wear, depending significantly on the operating conditions. We discuss the wear mechanisms and the correlations of wear effects in the tribo contact area of the sealing system.Merkle, Lukas ; Bauer, Frank: Lastkollektive RWDR – Gestaltung von Lastkollektiven zur Prüfung von Radial-Wellendichtungen (FVA Forschungsheft 1512 Nr. Abschlussbericht, Vorhaben 696I II / 696 IV). Frankfurt am Main : Forschungsvereinigung Antriebstechnik e.V., 2022 — 723
Zusammenfassung
Elastomere Radial-Wellendichtungen werden in fast jedem antriebstechnischen Aggregat eingesetzt. Ohne Abdichtung der Wellendurchtrittstelle ist ein Betrieb unmöglich. Obwohl die Dichtringe millionenfach eingesetzt werden, kommt es immer wieder zum Systemschaden „Leckage“. Die Dichtringe zeigen als tribologischen Primärschaden beispielsweise Verhärtung, Risse oder exzessiven Verschleiß. Eine Berechnung der Lebensdauer ist für RWDR nach wie vor nicht möglich, daher sind Prüfläufe das einzige Werkzeug zur sicheren Auslegung von Dichtsystemen. Die Forschungsvorhaben der Projektreihe 696 haben zum Ziel, KmU und anderen Unternehmen einen Leitfaden zur systematischen Prüfung von Dichtsystemen zur Verfügung zu stellen. Wichtigstes Werkzeug dafür ist der vollständige Gesamtschadenskatalog. Das Wissen aus 696 I bis IV zum Thema Schadenanalyse, einstufigen und wechselnden Belastungen sowie zur Validierung der Ergebnisse unter industriellen Einsatzbedingungen wird in diesem Gesamtbericht zusammengeführt. Die Unternehmen können mit dem Leitfaden Schadensfälle analysieren und angepasste Kollektive für tribometrische Versuche erstellen. Damit können Dichtsysteme untersucht und optimiert werden. Leckage und Imageverlust können sicher vermieden werden. Die Erkenntnisse sind digitalisiert und stehen für den Wissenstransfer zur Verfügung. In der Projektreihe 696 wurden 278 Prüfläufe mit einer kumulierte Versuchslaufzeit von 108.117,4 h
(= 12,3 Jahre) und einem kumulierten Laufweg von fast 2 Millionen km individuell ausgewertet. Das Ziel des Forschungsvorhabens wurde erreicht.Merkle, Lukas ; Baumann, Matthias ; Bauer, Frank: Back-Pumping Rate Measurement of Elastomeric Radial Lip Seals in Converse Installation: Basics, Wear Formation and Long-Term Tests. In: Proceedings M2D2022, 2022. — ISBN 978-989-54756-3-6, S. 363–374 — 710 (peer-review)
Zusammenfassung
Radial lip seals are used in various sizes and designs to seal shaft interfaces. In contrast to other sealing systems, elastomeric radial lip seals have a back-pumping capability. Fluid is pumped under the sealing edge from the air side to the fluid side. The simplest method for measuring the back-pumping rate is the converse installation of the radial lip seal. This paper describes the current state of the art in back-pumping rate measurement. It shows the advantages over other methods and the limitations of the method. For the converse installation, there was always the assumption of hydrodynamic lubrication. This means there would be only minimal initial run in effects and no further wear. Current research work however, question this assumption. To analyze the wear formation during back-pumping rate measurements, various long-term tests were carried out. The resulting wear is compared with identical tests in normal installation.