Helical seal for multi-stage compressor

A compressor system comprising:

• a compressor comprising:
• a first compressor wheel;
• a second compressor wheel;
• a drive shaft extending along a longitudinal axis from a proximal end to a distal end, the drive shaft comprising:
• an outer shaft extending from the first compressor wheel to the second compressor wheel;
• and
• an inner shaft disposed radially inwards of the outer shaft and extending through the first compressor wheel and the second compressor wheel,
• wherein the drive shaft connects the first compressor wheel to the second compressor wheel, and wherein the distal end of the drive shaft is distal to the first compressor wheel;
• and
• two or more helical seals disposed on the outer shaft of the drive shaft, each helical seal of the two or more helical seals extending away from an outer surface of the outer shaft and around a circumference of the outer shaft, wherein an outer diameter of each helical seal of the two or more helical seals is greater than an outer diameter of the outer shaft;
• a housing configured to retain the compressor, the housing comprising:
• a channel extending along the longitudinal axis and configured to retain the drive shaft, wherein the two or more helical seals are configured to inhibit flow of fluid between the first compressor wheel and the second compressor wheel through the channel;
• and
• a motor coupled to the proximal end of the drive shaft and configured to apply a rotary force on the drive shaft.

A method comprising:

• position a first compressor wheel of a compressor within a housing;
• connecting a second compressor wheel of the compressor to the first compressor wheel by at least partially inserting an outer shaft of a drive shaft of the compressor into the first compressor wheel, wherein the outer shaft is connected to the second compressor wheel, and wherein the outer shaft of the drive shaft comprises:
• two or more helical seals disposed on the outer shaft, each helical seal of the two or more helical seals extending away from an outer surface of the outer shaft and around a circumference of the outer shaft;
• inserting an inner shaft of the drive shaft through an inner lumen of the outer shaft along a longitudinal axis of the compressor;
• and
• affixing the inner shaft to the first compressor wheel and the second compressor wheel.