Screw compressor having a screw rotor whose pitch changes in an axial direction from a suction end surface toward a discharge end surface

Patent metadata

Field	Value
Publication number	US-11933300-B2
Application number	US-202017760790-A
Country	US
Kind code	B2
Filing date	Sep 10, 2020
Priority date	Oct 7, 2019
Publication date	Mar 19, 2024
Grant date	Mar 19, 2024

Abstract

This screw compressor is provided with a screw rotor, a casing accommodating the screw rotor, and a liquid feed mechanism for feeding a liquid into an operating chamber enclosed by the casing, wherein the pitch of the screw rotor changes in the axial direction from a suction end surface toward a discharge end surface.

First claim

The invention claimed is:

1. A screw compressor comprising:
a screw rotor;
a casing which accommodates the screw rotor; and
a liquid feed mechanism configured to feed a liquid into an operating chamber enclosed by the casing,
wherein a pitch of the screw rotor increases continuously in an axial direction from a suction end surface toward a discharge end surface.

2. The screw compressor according to claim 1 ,
wherein the liquid feed mechanism feeds a liquid to the screw rotor from a hole formed by penetrating the casing.

3. The screw compressor according to claim 1 ,
wherein the liquid feed mechanism is disposed on the discharge end surface side.

4. The screw compressor according to claim 1 ,
wherein the liquid feed mechanism is disposed at a position in which a pressure of the operating chamber communicating with a liquid feed port installed at a certain position of an inner wall of a bore in a screw rotor having an equal pitch and having a shape and a dimension of a cross-section orthogonal to the axial direction of the screw rotor, a total winding angle, and a length which are the same as those of the screw rotor becomes higher than a pressure of the operating chamber communicating with a liquid feed port installed at the same position as the screw rotor.

5. The screw compressor according to claim 1 ,
wherein the liquid feed mechanism is disposed on the discharge end surface in relation to a surface parallel to the suction end surface and the discharge end surface and including a point in which a helix angle of the screw rotor is the same as a helix angle of a screw rotor having an equal pitch and having a shape and a dimension of a cross-section orthogonal to the axial direction of the screw rotor, a total winding angle, and a length which are the same as those of the screw rotor.

6. The screw compressor according to claim 1 ,
wherein the liquid feed mechanism includes a fine liquid feed port.

7. The screw compressor according to claim 1 , further comprising:
a plurality of liquid feed ports provided in the axial direction of the screw rotor.

8. The screw compressor according to claim 1 ,
wherein the liquid feed mechanism includes at least one or more fine liquid feed ports and at least one or more drill hole liquid feed ports.

9. The screw compressor according to claim 1 ,
wherein the liquid feed mechanism includes a jet collision nozzle or a fan spray nozzle.

Assignees

• Hitachi Industry Equipment Systems Co Ltd

Inventors

• Tanimoto Shota
• Yorikane Shigeyuki
• Komatsu Tomohiro
• Tsuchiya Takeshi
• Chiba Kotaro

Classifications

• F04C18/16 Primary

  with helical teeth, e.g. chevron-shaped, screw type {(for non-parallel axes of movement F04C18/48)} · CPC title

• F04C29/0007

  Injection of a fluid in the working chamber for sealing, cooling and lubricating (sealing only F04C27/00; lubrication only F04C29/02; cooling F02B47/02, F02D21/00, F02M25/00) · CPC title

• F04C29/02

  Lubrication (of machines or engines in general F01M); Lubricant separation (separation in general B01D) · CPC title

• F04C2250/20

  of the rotor · CPC title

• F04C18/082 Primary

  Details specially related to intermeshing engagement type pumps · CPC title