Screw compressor

• US 3,902,827 A
• Filed: 07/10/1974
• Issued: 09/02/1975
• Est. Priority Date: 07/20/1973
• Status: Expired due to Term

• Current Assignee: Lauritz Benedictus Schibbye
• Original Assignee: Lauritz Benedictus Schibbye
• Inventors: Schibbye, Lauritz Benedictus
• Primary Examiner(s): Vrablik, John J.
• Application Number:
  US05/487,145
• Time in Patent Office: 419 Days
• Field of Search: 418/79,97,98,99,142,144,197,201-203
• US Class Current: 418/79
• CPC Class Codes: F04C 18/16 with helical teeth, e.g. chevron-shaped, screw type for non-parallel axes of movement F04C18/48

Abstract

A screw rotor compressor in which the high pressure ends of the rotors are provided with annular sealing edges cooperating with the high pressure end wall of the working space to provide central sealed chambers around the rotor shafts, which chambers are in communication with the low pressure side of the compressor.

Claims

1. Screw compressor, of the type comprising two intermeshing rotors having helical lands and grooves disposed within a working space having low pressure and high pressure ports disposed generally diagonally thereof and adjacent to a low pressure and a high pressure end wall of the working space, respectively, characterized by a sealing ring surrounding the shaft of each rotor and disposed between the end plane of the rotor and the high pressure end wall of the working space, and by a drainage channel in said high pressure end wall forming a communication between the volume surrounded by said sealing ring and an area of the working space located within the low pressure phase of the compressor.

2. Screw compressor as defined in claim 1 comprising a bearing chamber along the rotor shaft housing a rotor shaft bearing and having bearing lubricating oil supplied thereto, and wherein said volume surrounded by the sealing ring communicates with said bearing chamber whereby said bearing lubricating oil is drained through said drainage channel.

3. Screw compressor as defined in claim 1, in which said drainage channel comprises a relieved portion in the surface of said high pressure end wall of the working space.

4. Screw compressor as defined in claim 1, in which said sealing ring is shaped as a thin annular edge fixed to and projecting from the end plane of the rotor.

5. Screw compressor as defined in claim 4 comprising a bearing chamber along the rotor shaft housing a rotor shaft bearing and having bearing lubricating oil supplied thereto, and wherein said volume surrounded by the sealing ring communicates with said bearing chamber whereby said bearing lubricating oil is drained through said drainage channel.

6. Screw compressor as defined in claim 4, wherein said sealing ring axially projects from the end plane of the rotor.

7. Screw compressor as defined in claim 4, wherein said thin annular projecting edge is located just inside the bottoms of the rotor grooves.

8. Screw compressor as defined in claim 4, in which said drainage channel comprises a relieved portion in the surface of said high pressure end wall of the working space.

9. Screw compressor as defined in claim 8, comprising a bearing chamber along the rotor shaft housing a rotor shaft bearing and having bearing lubricating oil supplied thereto, and wherein said volume surrounded by the sealing ring communicates with said bearing chamber whereby said bearing lubricating oil is drained through said drainage channel.