US Patent 11920605 Rotating machine and mating ring included therein

A rotating machine includes a shaft, a first impeller wheel, and a second impeller wheel. The rotating machine also includes a first seal assembly including a first carbon ring disposed about the shaft, with the first carbon ring having a first carbon surface. The first seal assembly also includes a first mating ring disposed about the shaft, with the first mating ring having a first mating surface facing and configured to contact the first carbon surface. The rotating machine additionally includes a second seal assembly including a second carbon ring disposed about the shaft, with the second carbon ring having a second carbon surface. The second seal assembly also includes a second mating ring disposed about the shaft, with the second mating ring having a second mating ring surface facing and configured to contact the second carbon surface.