ASSESSMENT OF THE SURFACE CONDITIONS OF GAS-LUBRICATED FACE-SEAL SEALING RINGS

摘要

The paper presents a study of surface condition of stationary and rotary rings of a gas-lubricated face seal before and after 25 hours of operation on a test bench, with 75 cycles of start-ups and stops of the drive. For evaluation of surface conditions, flatness deviation and a selected 2D and 3D roughness parameters were measured. Profiles of the roughness, material ratio curves, topography, and surface maps in colour before and after 25 hours of operations were presented. It has been found that wear of the end faces of the sealing rings differs between sintered silicon carbide and carbon graphite. In the case of the stationary ring made of sintered silicon carbide with a hardness of 3000 HV, there is a slight increase in values of almost all (except Sp) measured 3D amplitude parameters: Sa, Sq, Sv, St. In the case of the rotary ring made of carbon graphite with hardness of about 115 HR a noticeable reduction in values of these parameters was found. Changes in 2D and 3D roughness parameters of end faces of the stationary and rotary rings allow confirming the almost contact-free character of the face seal operation.