Hitachi Industrial Equipment Systems Co., Ltd.

Hitachi, Ltd.

Kawamura Research Laboratories, Inc.

Natsuki Kawabata

Kazuaki Shiinoki

Akira Suzuki

Isamu Kawano

Masakazu Aoki

Hitoshi Nishimura

Hirotaka Kameya

Shigeru Machida

Masakatsu Okaya

Shumpei Yamazaki

Yoshio Kobayashi

Kiminori Iwano

Toshikazu Harashima

Toshiaki Yabe

Hideki Fujimoto

Yukiko Ikeda

Iwao Aoki

Masahiro Kawamura

Fumio Takeda

Kohei Sakai

Tatsuo Natori

Muneo Mizumoto

Hirokatsu Kohsokabe

Yusuke Nagai

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.

Oil-free screw compressor coated with a base resin, a solid lubricant and a heat-resistant additive

A scroll-type fluid machine reduces intrusion of abrasion powders, generated by sliding of a conductor causing an orbiting scroll side and a fixed scroll side to be conducted, into a compression chamber, and improves reliability of a compressor. The scroll-type machine includes a casing, a fixed scroll having a flange surface attached to the casing, and a wrap portion provided at an end plate, an orbiting scroll having a wrap portion provided at the end plate, and provided in an opposed relationship with the fixed scroll, a drive shaft connected through a crank portion to the orbiting scroll, an orbiting bearing, a face seal portion arranged between the orbiting scroll and the fixed scroll, a cooling fan, and an orbiting scroll side conductive brush.

Scroll-type fluid machine with grease-lubricated orbiting bearing

An oil free compressor includes a cooling fan, a low-pressure stage air-cooled heat exchanger, a high-pressure stage air-cooled heat exchanger, and a lubricating oil air-cooled heat exchanger. The cooling fan is provided independently 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.

Oil free compressor system

A high reliability water injected scroll air compressor is provided with an orbiting scroll, a fixed scroll corresponding to the orbiting scroll, a motor that generates driving force for making the orbiting scroll orbit the fixed scroll, a compressing path from a suction port to a discharge port, and a portion for injecting water into the compressing path. The operation is controlled by a switching operation in which water is injected into the compressing path and then no water is injected. Corrosion, failure of activation, and concerns about wrap contact when water is injected into an air end are avoided by switching the operation with water injection and the operation without water injection so as to prevent water from remaining in the air end.

Water injected scroll air compressor

An oilless screw compressor incorporating water-cooled cooling units for cooling compressed air discharged from compressor bodies having a pair of male and female screw rotors which can be rotated in a contactless and oilless manner, the cooling units comprising a plate type heat-exchanger, and the amount of cooling water for the plate type heat-exchanger being adjustable. With this configuration, a difference between a temperature during load operation and a temperature upon automatic stopping and during unload operation of the compressor can be reduced, so that the cooling unit can be restrained from being damaged or broken within a short period, thereby it is possible to provide a highly reliable oilless screw compressor.

Oilless screw compressor and compressed air cooling unit

Screw compressor

As pressure in a water tank rapidly rises when water inside a compressor is evaporated by the high temperature of compressed air and this situation makes the operation unstable, an object of the present subject matter is to address this problem. A water injected scroll air compressor is provided with: an air end of the scroll air compressor; a driving unit that generates driving force for the air end; a compressing path from a suction port to a discharge port; a portion to inject water into the compressing path; a discharge piping of air discharged from the air end; a tank provided on a path of the discharge piping for storing water separated from the compressed air; and a cooler that is provided on the path of the discharge piping between the tank and the air end and cools the compressed air discharged from the air end.

Disclosed is a water-injection type scroll air compressor whose pre-stopping operation time for drying can be reduced while enhancing compressor efficiency. The compressor bodyincludes a water supply linefor supplying water to a water feederconnected to an air suction line. The water supply lineis provided with a control valvethat can control a flow rate of the water. A controllerconducts driving control of the control valvein a 5&#xd7;10to 40&#xd7;10range of an injected-water volume ratio (more specifically, a volume ratio between an intake air flow rate and injected-water flow rate in the water feederof the suction line) and at the same time, in an injected-water volume ratio range of the compressor characterized so that an increase rate of overall adiabatic efficiency of the compressor per 1&#xd7;10increase rate of the injected-water volume ratio stays less than 2% of an original or initial value.

Water-injection type scroll air compressor

A water-injected compressor, which injects the water inside the separatorinto the compressor and discharges the water along with compressed air into the separator and then gains condensed and separated water, has the compressor stopping and then, if staying at a stop for a predetermined duration of time without activating, becoming activated and operating for a set duration of time.

Water-injected compressor

The invention downsizes and simplifies structures of a compressor and its driving system apparatus, and achieves a reduction of a noise. An oil free screw compressor is constituted by compressor main bodies compressing a gas, a motor driving rotors of the compressor main bodies via step-up gears, a gear casing storing the step-up gears, cooling apparatuses cooling a discharge air and the like. An oil tank is provided independently from the gear casing, the motor is fixed to a common base, the gear casing is integrally attached to the motor via a flange, and the compressor main bodies are integrally attached to the gear casing via the flange. Further, the cooling apparatuses are arranged in an upper side of the driving system apparatus, and a cooling fan is installed in an upper side thereof.

Oil free screw compressor

In a double toothed type scroll compressor, spiral wraps are formed on both sides of an end plate of an orbiting scroll, and wraps adapted to engage with the spiral wraps are formed on a stationary scroll. A dust wrap is formed on a side diametrically outside of the wrap of the stationary scroll. Grooves are formed on ends of the respective wraps to receive therein seal members formed of a high polymer material. Electric charge of static electricity produced when the seal members slide on surfaces of the mating end plate is made to flow from a bolt provided on an end of a crankshaft to the stationary scroll through a brush, thereby preventing accumulation of electric charge in a crankshaft.

Growing community of inventors

Shizuoka, Japan

Natsuki Kawabata