Influence of Manufacturing Tolerances on the Behavior of Pneumatic Seals using EHL Simulations

The sealing friction in pneumatic spool valves is influenced by several factors, like the lubricant and sealing material properties, the topography of the contacting surfaces and the geometry. In practice, surface roughness and geometry are subject to manufacturing tolerances. This publication presents a simulative investigation on how these tolerances affect the sealing contact. For that, friction force and leakage are calculated for different bore diameters and surface roughness. An increase in bore diameter leads to an almost linear decrease in friction and an increase in expected leakage. Higher surface roughness amplitudes are predicted to increase both friction and expected leakage.