Systems and methods for integrally geared centrifugal compressor to maintain rotor concentricity with differing pinion gear tooth counts

A method for operating an integrally geared centrifugal compressor system for compressing a fluid, the method comprising:

• introducing a first eccentric cartridge into a gearbox defining an interior longitudinal cavity having a center axis, the first eccentric cartridge housing a first bearing assembly through which a first rotor coupled to a first pinion extends to support rotation of the first rotor about a first rotational axis by a bull gear, the first eccentric cartridge configured to eccentrically arrange the first rotational axis relative to the center axis of the gearbox;
• and
• interchanging the first eccentric cartridge with a second eccentric cartridge, the second eccentric cartridge housing a second bearing assembly through which a second rotor coupled to a second pinion extends to support rotation of a second rotor about the second rotational axis by the bull gear, the second eccentric cartridge configured to eccentrically arrange the second rotational axis relative to the center axis of the gearbox, wherein the first rotational axis is eccentrically arranged relative to the second rotational axis.

A method for operating an integrally geared centrifugal compressor system for compressing a fluid, the method comprising:

• introducing a first eccentric cartridge into a gearbox defining an interior longitudinal cavity, the first eccentric cartridge housing a first bearing assembly through which a first rotor coupled to a first pinion extends to support rotation of the first rotor about a first rotational axis by a bull gear, the first eccentric cartridge having a first outer surface and a first inner surface, wherein the first inner surface is eccentric relative to the first outer surface to align the first rotational axis with a center axis of the first bearing assembly;
• and
• interchanging the first eccentric cartridge with a second eccentric cartridge, the second eccentric cartridge housing a second bearing assembly through which a second rotor coupled to a second pinion extends to support rotation of a second rotor about the second rotational axis by the bull gear, the second eccentric cartridge having a second outer surface and a second inner surface, wherein the second inner surface is eccentric relative to the second outer surface to align the second rotational axis with a center axis of the second bearing assembly, wherein the first rotational axis is eccentrically arranged relative to the second rotational axis.