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US 5,641,280 AGranted
Rotary screw compressor with shaft seal
AssigneeSvenska Rotor Maskiner AB
InventorKarlis Timuska
Life of this patent
Estimating the term…
Abstract
A rotary screw compressor for oil-free air, wherein at least one of the shaft journals (11) of the rotors (10) has a seal arrangement between the rotor (10d) and an oil-lubricated bearing (12). The seal arrangement includes at least three frictionless seals (13, 14, 15) separated by annular chambers (16,17). The outermost annular chamber (17) is connected to a source of pressurized air through a supply channel (19) for supplying blocking air to the seal, and another (16) of the annular chambers communicates with a withdrawal channel (18).
Claims9
A rotary screw compressor for oil-free air, comprising:
- an inlet channel (24);
- an outlet channel (27);
- and
- at least one compression stage, each compression stage including at least one screw rotor (10;
- 10, 110) with at least one shaft journal (11;
- 11a, 111a, 111b) mounted in an oil lubricated bearing (12;
- 12a, 112a, 112b), said at least one shaft journal (11;
- 11a, 111a, 111b) having a seal between said screw rotor (10;
- 10, 110) and said oil lubricated bearing (12;
- 12a, 112a, 112b);
- said seal including at least three frictionless seal portions (13, 14, 15) surrounding said at least one shaft journal (11, 11a, 111a, 111b) and a plurality of annular chambers (16, 17;
- 16a, 116a, 116b, 17a, 117a, 117b) surrounding said shaft journal (11;
- 11a, 111a, 111b), said frictionless seal portions (13, 14, 15) and said annular chambers (16, 17;
- 16a, 116a, 116b, 17a, 117a, 117b) being arranged in an alternating sequence along said at least one shaft journal (11, 11a, 111a, 111b);
- a supply channel (19, 19a, 119a, 119b) connecting an outermost one of said annular chambers (17, 17a, 117a, 117b) to a source of pressurized air;
- and
- a withdrawal channel (18, 18a, 118a, 118b) connected to another of said annular chambers (16, 16a, 116a, 116b), said withdrawal channel being positioned between said outermost annular chamber (17, 17a, 117a, 117b) and the rotor, wherein the term outermost is being defined as most remote from the screw rotor.
14 more elements
Dependencies are inferred from the claim text.