An Experimental Study on Starved Grease Lubricated Contacts

• Type: Article in International Scientific Journal
• Date: 2018

Authors

Goncalves, DEP (Author) Other; Campos, AV (Author) Other; Jorge Seabra (Author) FEUP

Journal

Title: Lubricants

Vol. 6

Final page: 82

Publisher: MDPI

Indexing

ISI Web of Knowledge - 2 Citations

Scopus - 8 Citations

Other information

Authenticus ID: P-00P-MFC

DOI: 10.3390/lubricants6030082

Abstract (EN): The film thickness of a ball-on-disc contact lubricated with four greases of different formulations was measured under different operating conditions until starvation. Two polymer-thickened greases and two lithium-thickened greases, formulated with base oils of different nature and/or viscosity, were tested. The central film thickness was measured under constant operating conditions (load, temperature, slide-to-roll ratio) varying only the entrainment speed. In a separate test, the film thickness was measured over time with all operating conditions set to constant. Pictures of the film thickness profile across the contact area were also registered. The results were compared with the fully flooded results. The coefficient of friction (COF) was measured in a ball-on-disc contact under equal operating conditions and the results were correlated with the film thickness findings. The different grease formulations and the influence of the operating conditions on the film thickness and COF were discussed. The polymer thickened the greases, promoting lower COF and higher film thickness, especially when there is thickener material crossing the contact which happens quite often for these greases.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 18