IP Library › Granted Patent US 8,801,412
Granted Patent B2
US 8,801,412 · App. 13/248,110 · Granted Aug 12, 2014

Screw compressor

Inventors: Yukiko Ikeda (Kasumigaura, JP); Kazuaki Shiinoki (Yokohama, JP); Masakatsu Okaya (Shizuoka, JP); Natsuki Kawabata (Shizuoka, JP); Masahiro Kawamura (Tokyo, JP); Iwao Aoki (Konosu, JP)
Assignees: Hitachi Industrial Equipment Systems Co., Ltd.; Kawamura Research Laboratories, Inc.
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Quick Facts
Patent No.
US 8,801,412
App. No.
13/248,110
Granted
Aug 12, 2014
Kind
B2
Abstract

In order to prevent deterioration in performance of an oil-free screw compressor and scuffing caused by rust, surfaces of both male and female rotors are coated with heat-resistance coatings containing a solid lubricant. A coating contains Polyimide resin to which Molybdenum disulfide, as a solid lubricant, and Aluminum oxide and Titanium oxide, as additives, are added. Accordingly, it is possible to realize a coating that is higher in heat resistance and longer in lifetime than a conventional one.

Claims (38)

1. A solid lubrication heat-resistant coating comprising:

at least 50 wt % of a base resin containing an imide bond;

15 to 35 wt % of a solid lubricant comprising Molybdenum disulfide; and

and 4 to 14 wt % of heat-resistant additives dispersed in the resin, the heat-resistant additives comprising Aluminum oxide and Titanium oxide at a ratio of 3:7 to 7:3.

2. The solid lubrication heat-resistant coatings according to claim 1 , further comprising:

1.5 to 3.5 wt % of a rust prevention pigment.

3. The solid lubrication heat-resistant coatings according to claim 1 , further comprising:

0.5 to 2.5 wt % of Talc.

4. A solid lubrication heat-resistant coating comprising:

at least 50 wt % of a base resin containing an imide bond;

15 to 35 wt % of a solid lubricant comprising Molybdenum disulfide; and

8 to 15 wt % of heat-resistant additives dispersed in the resin, the heat-resistant additives comprising Titanium oxide and Silicon nitride dispersed in a range of 4% or less.

5. A coating varnish comprising:

a solid lubrication heat-resistant coating diluted with a solvent, the solid lubrication heat-resistant coating comprising at least 50 wt % of a base resin containing an imide bond, 15 to 35 wt % of a solid lubricant comprising Molybdenum disulfide, and 4 to 14 wt % of heat-resistant additives dispersed in the resin, the heat-resistant additives comprising Aluminum oxide and Titanium oxide at a ratio of 3:7 to 7:3.

6. The coating varnish according to claim 5 , wherein the solid lubrication heat-resistant coating further comprises:

1.5 to 3.5 wt % of a rust prevention pigment.

7. The coating varnish according to claim 5 , wherein the solid lubrication heat-resistant coating further comprises:

0.5 to 2.5 wt % of Talc.

8. A coating varnish comprising:

a solid lubrication heat-resistant coating diluted with a solvent, the solid lubrication heat-resistant coating comprising at least 50 wt % of a base resin containing an imide bond, 15 to 35 wt % of a solid lubricant comprising Molybdenum disulfide, and 8 to 15 wt % of heat-resistant additives dispersed in the resin, the heat-resistant additives comprising Titanium oxide and Silicon nitride dispersed in a range of 4% or less.

9. An oil-free screw rotor, comprising:

a solid lubrication heat-resistant coating formed on an outer surface of the rotor, the solid lubrication heat-resistant coating comprising at least 50 wt % of a base resin containing an imide bond, 15 to 35 wt % of a solid lubricant comprising Molybdenum disulfide, and 8 to 15 wt % of heat-resistant additives dispersed in the resin, the heat-resistant additives comprising Titanium oxide and Silicon nitride dispersed in a range of 4% or less.

10. An oil-free screw rotor, comprising:

a solid lubrication heat-resistant coating formed on an outer surface of the rotor, the solid lubrication heat-resistant coating comprising at least 50 wt % of a base resin containing an imide bond, 15 to 35 wt % of a solid lubricant comprising Molybdenum disulfide, and 4 to 14 wt % of heat-resistant additives dispersed in the resin, the heat-resistant additives comprising Aluminum oxide and Titanium oxide at a ratio of 3:7 to 7:3.

11. The screw rotor according to claim 10 , wherein the solid lubrication heat-resistant coating further comprises:

1.5 to 3.5 wt % of a rust prevention pigment.

12. The screw rotor according to claim 10 , wherein the solid lubrication heat-resistant coating further comprises:

0.5 to 2.5 wt % of Talc.

13. An oil-free screw compressor that sucks and discharges fluid by combining a male rotor and a female rotor on outer surfaces of which spiral profiles are formed in the axis direction, comprising:

a solid lubrication heat-resistant coatings formed on the outer surface of the male and female rotors, the solid lubrication heat-resistant coatings on each the male and female rotors comprising at least 50 wt % of a base resin containing an imide bond, 15 to 35 wt % of a solid lubricant comprising Molybdenum disulfide, and 8 to 15 wt % of heat-resistant additives dispersed in the resin, the heat-resistant additives comprising Titanium oxide and Silicon nitride dispersed in a range of 4% or less.

14. An oil-free screw compressor that sucks and discharges fluid by combining a male rotor and a female rotor on outer surfaces of which spiral profiles are formed in the axis direction, comprising:

a solid lubrication heat resistant coating formed on the outer surface of the male and female rotors, the solid lubrication heat-resistant coatings on each the male and female rotors comprising at least 50 wt % of a base resin containing an imide bond, 15 to 35 wt % of a solid lubricant comprising Molybdenum disulfide, and 4 to 14 wt % of heat-resistant additives dispersed in the resin, the heat-resistant additives comprising Aluminum oxide and Titanium oxide at a ratio of 3:7 to 7:3.

15. The screw compressor according to claim 14 , wherein the resin comprises a Polyamideimide.

16. The screw compressor according to claim 14 , wherein the resin comprises a Polyimide.

17. The screw compressor according to claim 14 , wherein the solid lubrication heat-resistant coatings on each the male and female rotors further comprise:

1.5 to 3.5 wt % of a rust prevention pigment.

18. The screw compressor according to claim 14 , wherein the solid lubrication heat-resistant coatings on each the male and female rotors further comprise:

0.5 to 2.5 wt % of Talc.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 30, 2011
From: IKEDA, YUKIKO; SHIINOKI, KAZUAKI; OKAYA, MASAKATSU; KAWABATA, NATSUKI; KAWAMURA, MASAHIRO; AOKI, IWAO
To: HITACHI INDUSTRIAL EQUIPMENT SYSTEMS CO., LTD.; KAWAMURA RESEARCH LABORATORIES, INC.
Reel/Frame 027298/0718 →
Priority Claims (1)
JP 2010-239741 · Oct 26, 2010 · national
Continuity (1)
Related Publication 20120100029A1 · Apr 26, 2012