Theoretical Analyses and Design Guidelines of Oil-Film-Lubricated Mechanical Face Seals with Spiral Grooves

The oil-film-lubricated mechanical face seal is a kind of pure hydrodynamic lubricated noncontacting mechanical face seal with zero leakage. On the basis of systematic theoretical analyses, the design calculation formulas under zero-leakage condition for mechanical face seals with different spiral groove patterns, including double-row spiral grooves such as splay pattern and single-row spiral grooves, are derived. The effects of groove geometry including number of grooves, balance ratio, spring force, rotating speed, and differential pressure on the seal performance are discussed in detail. Finally, the design guidelines of this kind of seal with zero leakage and no wear are put forward. The seals designed according to the guidelines can withstand the pressure disturbance and speed change by means of a slight change of oil-film thickness. Seals developed according to the design guidelines have been tested on a test rig in detail and applied successfully in high-speed turbocompressors of the oil refinery and petrochemical industries.