Oil-free water-injected screw air compressor

A screw compression device comprising:

• a housing defining a working space in which air is to be compressed;
• a male screw rotor disposed in the working space;
• a female screw rotor disposed in the working space, wherein an intermeshing of the male screw rotor and the female screw rotor causes compression of air;
• a separator tank to separate air and water in an air-water mixture and to supply water to the working space for cooling the working space;
• a first bearing chamber displaced from the working space in an axial direction of the screw compression device and comprising:
• a first bearing to support at least one of:
• the male screw rotor and the female screw rotor;
• a lubricant sump to store lubricant for lubrication of the first bearing;
• a first gear coupled to one of:
• the female screw rotor and the male screw rotor;
• and
• a lubricant splasher coupled to the first gear, wherein the lubricant splasher comprises a groove to collect lubricant from the lubricant sump and splash the collected lubricant on the first bearing during rotation of the first gear;
• a first sealing system comprising a plurality of seals arranged between the working space and the first bearing in the following order:
• a ring seal;
• a first labyrinth seal;
• a second labyrinth seal, and
• a lip seal, wherein a first annular space is formed between the ring seal and the first labyrinth seal, a second annular space is formed between the first labyrinth seal and the second labyrinth seal, and a third annular space is formed between the second labyrinth seal and the lip seal, wherein
• the first annular space is connected to a low-pressure point on the working space that is to be maintained at a pressure lower than that of the first bearing chamber,
• the second annular space is supplied with compressed air from a compressed-air source through a flow regulator, and
• the third annular space is open to outside of the screw compression device.