Screw compressor

Patent metadata

Field	Value
Publication number	US-12313069-B2
Application number	US-202218273848-A
Country	US
Kind code	B2
Filing date	May 27, 2022
Priority date	Jun 1, 2021
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

A screw compressor has first and second screw rotors that suck, compress, and deliver a working medium; a first bearing supporting one end of the first screw rotor coupled to a rotating shaft of a power source; a casing housing the first screw rotor and first bearing; a shaft-sealing member located on an opposite side of a tooth profiler for the first screw rotor relative to the first bearing and seals a through hole in the casing, through which a shaft of the first screw rotor coupled to the output shaft of the power source is inserted; a partition wall isolating the first bearing from the shaft-sealing member; and a liquid-supply route that is provided in the casing and has a first liquid supply opening for supplying a lubricating liquid to the shaft-sealing member and a second liquid supply opening for supplying the lubricating liquid to the first bearing.

First claim

The invention claimed is:

1. A screw compressor for compressing a working medium, comprising:
first and second screw rotors that suck, compress, and deliver the working medium;
a first bearing that freely rotatably supports one end side of the first screw rotor whose one end side is coupled to a rotating shaft of a power source;
a casing that houses the first screw rotor and the first bearing;
a shaft sealing member that is located on an opposite side of a tooth profile unit for the first screw rotor relative to the first bearing inside the casing and seals a through hole in the casing, through which a shaft of the first screw rotor coupled to the rotating shaft of the power source is inserted;
a partition wall that isolates the first bearing from the shaft sealing member inside the casing; and
a liquid supply route that is provided in the casing and has a first liquid supply opening for supplying a lubricating liquid to the shaft sealing member and a second liquid supply opening for supplying the lubricating liquid to the first bearing.

2. The screw compressor according to claim 1 ,
wherein the shaft sealing member is disposed in a first space provided in the casing;
wherein the first bearing is disposed in a second space provided in the casing;
wherein the tooth profile unit with lobes formed thereon in the screw rotor with its one end side coupled to the rotating shaft of the power source is housed in a third space;
wherein the first space is isolated from the second space by the partition wall;
wherein the first space is connected to the third space to allow communication therebetween via a bypass communicating path; and
wherein the lubricating liquid supplied to the first space is discharged to the third space via the bypass communicating path.

3. The screw compressor according to claim 2 ,
comprising a communicating space which connects the second space and the third space to allow communication therebetween,
wherein the lubricating liquid which is supplied to the first bearing is discharged to the third space via the communicating space.

4. The screw compressor according to claim 3 ,
wherein the communicating space is formed so that when the first rotor and the second screw rotor are installed horizontally, a lowest end of the communicating space becomes lower than a lower-end position of an outer ring bore diameter of the first bearing.

5. The screw compressor according to claim 1 ,
wherein the first liquid supply opening is formed in the casing to supply the lubricating liquid to the first bearing from the screw rotor's side.

6. The screw compressor according to claim 1 , comprising:
a second bearing that freely rotatably supports an one end side of the second screw rotor which is the same as the one end side of the first screw rotor coupled to the rotating shaft of the power source; and
a third liquid supply opening provided in the casing to supply the lubricating liquid to the second bearing,
wherein the third liquid supply opening is formed in the casing to supply the lubricating liquid from the screw rotors' side to the first bearing.

Assignees

• Hitachi Industry Equipment Systems Co Ltd

Inventors

• Nagata Shuhei
• Yorikane Shigeyuki
• Morita Kenji
• Kajie Yuta
• Chiba Kotaro

Classifications

• F04C2240/60

  Shafts · CPC title

• F04C15/0038

  Shaft sealings specially adapted for rotary-piston machines or pumps · CPC title

• F04C2240/50

  Bearings · CPC title

• F04C15/0088

  Lubrication (of machines or engines in general F01M) · CPC title

• F04C2240/52

  for assemblies with supports on both sides · CPC title