Oil free compressor system

1. An oil free compressor system comprising:

a low-pressure stage compressor boosting air to a predetermined intermediate pressure;

a high-pressure stage compressor boosting compressed air, which was boosted to intermediate pressure, to a predetermined discharge pressure, the compressed air being boosted to the predetermined discharge pressure in a high-pressure chamber of the high-pressure stage compressor;

a motor driving the low-pressure stage compressor and the high-pressure stage compressor;

a low-pressure stage air-cooled heat exchanger cooling compressed air discharged from the low-pressure stage compressor;

a high-pressure stage air-cooled heat exchanger cooling the compressed air discharged from the high-pressure stage compressor; a main body of the high-pressure stage compressor and the low-pressure stage compressor, the main body including a bearing part; a speed changer;

a lubricating oil air-cooled heat exchanger cooling lubricating oil supplied to the bearing part of the main body of the high-pressure stage compressor and the low-pressure stage compressor, and the speed changer;

a cooling fan positioned to provide a cooling wind through the low-pressure stage air-cooled heat exchanger, the high-pressure stage air-cooled heat exchanger, and the lubricating oil air-cooled heat exchanger;

a duct arranged above the low-pressure stage compressor, the high-pressure stage compressor, and the motor in a package, the cooling fan being positioned in the duct and supplying cooling wind in a circumferential direction, and

the package covering the motor, a low pressure stage air-cooled heat exchanger, a high-pressure stage air-cooled heat exchanger, a lubricating oil air-cooled heat exchanger, the cooling fan and the duct;

wherein the low-pressure stage air-cooled heat exchanger, the high-pressure stage air-cooled heat exchanger are arranged in a circumferential direction, and the lubricating oil air-cooled heat exchanger is arranged at a top surface side of the cooling fan in the duct,

the cooling fan is provided inside of the duct, upstream of and separated by a distance from each of the low-pressure stage air-cooled heat exchanger, the high-pressure stage air-cooled heat exchanger, and the lubricating oil air-cooled heat exchanger; and

an exhaust duct is disposed downstream of each of the low-pressure stage air-cooled heat exchanger, the high-pressure stage air-cooled heat exchanger, and the lubricating oil air-cooled heat exchanger, each of the exhaust ducts connecting one of the heat exchangers to a top surface of the package.

2. The oil free compressor system according to claim 1 ,

wherein the high-pressure stage air-cooled heat exchanger is arranged on a top surface of the duct, and

the low-pressure stage air-cooled heat exchanger and the lubricating oil air-cooled heat exchanger are respectively arranged on different side surfaces of the duct.

3. The oil free compressor system according to claim 2 ,

wherein the low-pressure stage air-cooled heat exchanger is vertically arranged such that compressed air inlet and outlet of the low-pressure stage air-cooled heat exchanger are respectively located on a side of the low-pressure stage compressor and a side of the high-pressure stage compressor.

4. The oil free compressor system according to claim 3 ,

further comprising a passage provided which bypasses the cooling wind from the upstream side to a downstream side of the low-pressure stage air-cooled heat exchanger.

5. The oil free compressor system according to claim 2 ,

wherein the lubricating oil air-cooled heat exchanger is arranged on a lower side of the high-pressure stage air-cooled heat exchanger in a manner such as to partially overlap the high-pressure stage air-cooled heat exchanger when viewed from top of the exhaust duct.

6. The oil free compressor system according to claim 2 ,

further comprising a part of a pipe connecting together the high-pressure stage compressor and the high-pressure stage air-cooled heat exchanger arranged in the exhaust duct provided downstream of the low-pressure stage air-cooled heat exchanger.

7. The oil free compressor system according to claim 6 ,

further comprising a passage provided which passes through a high temperature part inside of the package from the upstream side of the low-pressure stage air-cooled heat exchanger and bypasses the cooling wind to the downstream side of the low-pressure stage air-cooled heat exchanger.

8. The oil free compressor system according to claim 7 ,

further comprising a retainer of an inner space of the duct shaped so as to be covered by the duct, except for the inlet port of the cooling fan.

9. The oil free compressor system according to claim 8 , wherein the retainer is made of a sound absorbing materials.

10. The oil free compressor system according to claim 7 ,

further comprising a rectifying guide provided in a near down stream side of the cooling fan on an inner surface side of the duct, the rectifying guide being configured to distribute the cooling wind in each direction to the low-pressure stage air-cooled heat exchanger, the high-pressure stage air-cooled heat exchanger, and the lubricating oil air-cooled heat exchanger.

11. The oil free compressor system according to claim 10 , wherein the rectifying guide is made of a sound absorbing materials.

12. The oil free compressor system according to claim 2 ,

further comprising a front-stage air-cooled heat exchanger included on an upstream side of the high-pressure stage air-cooled heat exchanger, and

the front-stage air-cooled heat exchanger is arranged in an exhaust duct coupling between the low-pressure stage air-cooled heat exchanger and the package.

13. The oil free compressor system according to claim 2 ,

further comprising an air exhaust part that carries a high-temperature air downstream of the high-pressure stage air-cooled heat exchanger is covered rectifying plate.

14. The oil free compressor system according to claim 2 ,

further comprising a low-temperature side of the exhaust duct of the low-pressure stage air-cooled heat exchanger covered rectifying plate.

15. The oil free compressor system according to claim 1 ,

wherein the cooling fan is a turbo fan.

16. The oil free compressor system according to claim 1 ,

further comprising a suction port for cooling the motor and a suction port for cooling the heat exchangers included on side surfaces of the package.

17. The oil free compressor system according to claim 1 ,

further comprising a fan motor driving the cooling fan arranged on a more upstream side of the cooling wind than the low-pressure stage air-cooled heat exchanger, the high-pressure stage air-cooled heat exchanger, and the lubricating oil air-cooled heat exchanger and also above the cooling fan.