Influence of grease rheology on thrust ball bearings friction torque.pdf

Tribology International 46 (2012) 106–113 Contents lists available at ScienceDirect Tribology International journal homepage: /locate/triboint Influence of grease rheology on thrust ball bearings friction torque Tiago Cousseau a, Beatriz M. Grac-a a,n, Armando V. Campos b,I, Jorge H.O. Seabra c a ˆ ~ Instituto de Engenharia Mecanica e Gestao Industrial—INEGI, Portugal b ´ Instituto Superior de Engenharia do Instituto Politecnico do Porto—ISEP-IPP, Portugal c Faculdade de Engenharia da Universidade do Porto—FEUP, Portugal a r t i c l e i n f o a b s t r a c t Article history: The friction torque and the operating temperatures in a thrust ball bearing were measured for seven Received 22 July 2010 different types of greases, including three biodegradable greases having low toxicity. These friction Received in revised form torque tests were performed using a modified Four-Ball machine. 7 June 2011 Rheological evaluations of the lubricating greases were made using a rheometer. Bleed oils were Accepted 10 June 2011 extracted from the greases and the dynamic viscosities were measured. Available online 30 June 2011 In order to compare the performance of the lubricant greases in terms of friction, the grease Keywords: characteristics were related to expe