Screw Compressor

• US 20190331115A1
• Filed: 07/04/2016
• Published: 10/31/2019
• Est. Priority Date: 07/04/2016
• Status: Abandoned Application

• Current Assignee: Hitachi Industrial Equipment Systems Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Industrial Equipment Systems Company Limited (Hitachi, Ltd.)
• Inventors: HARASHIMA, Toshikazu, NISHIMURA, Hitoshi, TSUCHIYA, Takeshi, SADAKATA, Kosuke, TAKANO, Masahiko
• Application Number:
  US16/311,424
• Publication Number:
  US 20190331115A1
• Time in Patent Office: Days
• CPC Class Codes: F01C 21/02 Arrangements of bearings bearing constructions F16C
• CPC Class Codes: F04C 18/16 with helical teeth, e.g. chevron-shaped, screw type for non-parallel axes of movement F04C18/48
• CPC Class Codes: F04C 2210/1005 Air
• CPC Class Codes: F04C 2240/50 Bearings
• CPC Class Codes: F04C 2240/56 Bearing bushings or details thereof
• CPC Class Codes: F04C 2240/809 Lubricant sump
• CPC Class Codes: F04C 2270/17 Tolerance; Play; Gap
• CPC Class Codes: F04C 23/02 Pumps characterised by combination with, or adaptation to, specific driving engines or motors
• CPC Class Codes: F04C 29/0085 Prime movers
• CPC Class Codes: F04C 29/026 Lubricant separation
• CPC Class Codes: F16C 2360/43 Screw compressors
• CPC Class Codes: H02K 21/24 with magnets axially facing the armatures, e.g. hub-type cycle dynamos
• CPC Class Codes: H02K 2205/03 Machines characterised by thrust bearings
• CPC Class Codes: H02K 2213/03 Machines characterised by numerical values, ranges, mathematical expressions or similar information
• CPC Class Codes: H02K 5/1735 radially supporting the rotary shaft at only one end of the rotor H02K5/1737 takes precedence
• CPC Class Codes: H02K 7/14 Structural association with mechanical loads, e.g. with hand-held machine tools or fans with fan or impeller for cooling the machine H02K9/06

Abstract

A screw compressor that enhances performance of a compressor main unit and a motor is provided. The screw compressor includes an oil-injected compressor main unit that compresses air with injecting oil in a compression chamber and an axial-gap motor that drives the compressor main unit. A male rotor of the compressor main unit has a suction-side shaft portion connected coaxially with a rotor shaft of the motor. The screw compressor further includes a suction-side bearing that rotatably supports the suction-side shaft portion of the male rotor. The suction-side bearing restricts axial movement of the suction-side shaft portion and bears a radial load and axial loads in both directions.

Claims

1. A screw compressor including a liquid-injected compressor main unit that includes a screw rotor and compresses gas with injecting liquid in a compression chamber defined by a tooth groove of the screw rotor and an axial-gap motor that drives the compressor main unit, the screw rotor having a motor-side shaft portion connected coaxially with a rotor shaft of the motor, the screw compressor comprising:

a bearing that rotatably supports the motor-side shaft portion of the screw rotor, wherein

the bearing restricts axial movement of the motor-side shaft portion and bears a radial load and axial loads in both directions.

2. The screw compressor according to claim 1, wherein

the compression chamber of the compressor main unit draws in gas via a suction port on a side adjacent to the motor and discharges compressed gas via a discharge port on a side opposite to the motor, and

the motor-side shaft portion is a suction-side shaft portion.

3. The screw compressor according to claim 2, further comprising:

a gas-liquid separator, disposed on a discharge side of the compressor main unit, for separating the liquid from the compressed gas discharged from the compressor main unit.

4. The screw compressor according to claim 1, wherein

the motor includes a first rotor disposed on an output side of the rotor shaft, a second rotor disposed on a non-output side of the rotor shaft, and a stator disposed between the first rotor and the second rotor, and

a dimension of a gap between the first rotor and the stator is greater than a dimension of a gap between the second rotor and the stator at room temperature.

5. The screw compressor according to claim 1, wherein

the motor includes a rotor disposed on the rotor shaft, a first stator disposed on an output side with respect to the rotor, and a second stator disposed on a non-output side with respect to the rotor, and

a dimension of a gap between the rotor and the first stator is smaller than a dimension of a gap between the rotor and the second stator at room temperature.

6. The screw compressor according to claim 1, wherein

the bearing includes combined angular contact ball bearings for face to face type or back to back type, and is held at a fixed position within a casing.