3-D SURFACE-ANALYSIS OF WORN SPHERICAL ROLLER THRUST-BEARINGS

Wear of boundary lubricated spherical roller thrust bearings has been characterised with 3-D surface measurements and analysis. Due to the c urved contact surface in a spherical roller thrust bearing, the roller s will undergo sliding in the contact. For an unskewed roller there wi ll be two points along each contact where the sliding velocity is zero . At all other points along the contact, sliding is present. Previousl y presented results from measurements of the contacting surfaces show that outside the zero sliding points there is a significant change in the washer surface profile due to wear. In order to study how the wear depends on the number of revolutions ten tests were performed. After the tests, 3-D surface roughness measurements were performed. The resu lts from these measurements show that there are different wear mechani sms involved. Initially, the surfaces are run in by possible plastic d eformation and two-body abrasion. After running-in, the surfaces are s ubjected to mild wear probably caused by two-body abrasion and/or dela mination wear. For the long term tests, three-body abrasion clearly in fluences the amount of wear. A 3-D parameter set was used to character ise the different wear mechanisms. Three amplitude parameters (S-a, S- q, S-2) and three of the functional Abbot curve parameters (S-pk, S-k, S-vk) were able to characterise all the wear mechanisms. (C) 1998 Els evier Science Ltd.