Abstract: In a screw compressor, a lobe profile of cross-sections perpendicular to the axial direction in a female rotor that rotates about a second rotation center changes in the axial direction. One lobe of the lobe profile of the female rotor includes: a first contour line defining a leading flank on a rotation direction side of the female rotor with a lobe bottom as a boundary point; a second contour line defining a trailing flank on an opposite side of the rotation direction; and a third contour line defining a lobe tip having both endpoints at which the female has the maximum radius.

Abstract: Provided is an air compressor that suppresses a rise in delivery temperature due to a change in atmospheric pressure, and consequently improves the life of parts. The air compressor 1 includes a motor 2, a compressor main body 3 driven by the motor 2 to compress air, a delivery pressure sensor 12 that senses a delivery pressure of the compressor main body 3, an atmospheric pressure sensor 13 that senses an atmospheric pressure, and a controller 15. The controller 15 compares the delivery pressure sensed by the delivery pressure sensor 12 with a set pressure, and performs operation control based on a result of the comparison. The controller 15 corrects the set pressure such that a ratio between the atmospheric pressure sensed by the atmospheric pressure sensor 13 and the set pressure becomes a set value set in advance.

Abstract: In order to reduce operation in a rotation-prohibited frequency range and to prevent resonance in a gas compressor wherein inverter control is performed, this gas compressor has: a compressor main body that compresses a gas; a motor that rotationally drives the compressor main body; an inverter that changes the rotational speed of the motor; a check valve arranged downstream from the compressor main body; a pressure detection means that detects load-side pressure downstream from the check valve; and a control device that, in accordance with the pressure detected by the pressure detection means, controls the frequency output by the inverter.

Abstract: A screw rotor which is hollow has improved performance against heat, pressure, rust, and the like. A screw rotor includes a screw portion of which an outer periphery has teeth and grooves having a helical shape and extending by a predetermined length in an axial direction. A radial cross section of at least a part of the screw portion includes a cross section of an outer surface portion forming the teeth and the grooves, a cross section of an axial center portion, a cross section of a support portion that connects an axial center side of the outer surface portion and an outer diameter side of the axial center portion, and a cross section of a hollow portion formed by the support portions adjacent to each other in a rotational direction and an axial center side inner surface of a tooth bottom or a tooth tip.

Abstract: A screw rotor which is hollow has improved performance against heat, pressure, rust, and the like. A screw rotor includes a screw portion of which an outer periphery has teeth and grooves having a helical shape and extending by a predetermined length in an axial direction. A radial cross section of at least a part of the screw portion includes a cross section of an outer surface portion forming the teeth and the grooves, a cross section of an axial center portion, a cross section of a support portion that connects an axial center side of the outer surface portion and an outer diameter side of the axial center portion, and a cross section of a hollow portion formed by the support portions adjacent to each other in a rotational direction and an axial center side inner surface of a tooth bottom or a tooth tip.

Abstract: In order to reduce operation in a rotation-prohibited frequency range and to prevent resonance in a gas compressor wherein inverter control is performed, this gas compressor has: a compressor main body that compresses a gas; a motor that rotationally drives the compressor main body; an inverter that changes the rotational speed of the motor; a check valve arranged downstream from the compressor main body; a pressure detection means that detects load-side pressure downstream from the check valve; and a control device that, in accordance with the pressure detected by the pressure detection means, controls the frequency output by the inverter.

Abstract: A bearing oil feeding amount is appropriately controlled with respect to specifications of a discharge pressure (bearing load) and a rotation speed.

Abstract: In order to reduce operation in a rotation-prohibited frequency range and to prevent resonance in a gas compressor wherein inverter control is performed, this gas compressor has: a compressor main body that compresses a gas; a motor that rotationally drives the compressor main body; an inverter that changes the rotational speed of the motor; a check valve arranged downstream from the compressor main body; a pressure detection means that detects load-side pressure downstream from the check valve; and a control device that, in accordance with the pressure detected by the pressure detection means, controls the frequency output by the inverter.

Abstract: A bearing oil feeding amount is appropriately controlled with respect to specifications of a discharge pressure (bearing load) and a rotation speed.

Abstract: 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.

Abstract: Provided are a structure of arranging a compressor main body and a compressor driving motor at a bottom of a package; including a duct on a top side thereof; arranging an inter cooler on a left side surface of the duct; arranging an after cooler on a top surface thereof; arranging an oil cooler on a front surface thereof; arranging a cooling fan inside of the duct; providing an exhaust port on a bottom surface of the duct; and respectively providing exhaust ducts connected to a top surface of the package on downstream sides of the coolers, and a structure of cooling air suctioned by the cooling fan from the suction port to the inside of the duct, passing through the coolers, and discharged upwardly from the package via the exhaust duct, implementing a compact oil free screw compressor with low noise capable of reducing an installation area.

Abstract: An oil-free scroll compressor prevents wraps from being broken and provides improved reliability. The oil-free scroll compressor includes an orbiting scroll member and fixed scroll members, and has compression channels into which water is injected each formed between the intake port and exhaust port provided in the fixed scroll member. The oil-free scroll compressor includes temperature sensors each of which detects temperature in the compression channel, regulating valves each of which controls ratio of the amount of the water to be injected into the respective compression channels to the total amount of the water to be injected into the compression channels, and controller which controls the opening degrees of the regulating valves such that a difference between the detected temperatures from the compression channels is small.

Abstract: A conventional machine package faces problems concerned with costs, weight, etc. and also a problem of antinomy that an attempt to enhance the noise reducing performance increases the airflow resistance and then deteriorates the cooling performance. Providing a sound absorbing structure with the heat radiation performance ensured within a practical range and then with considerably improved noise reducing effect achieves a low-noise machine package with a downsized casing and a reduced cooling fan power.

Abstract: An oil-free scroll compressor prevents wraps from being broken and provides improved reliability. The oil-free scroll compressor includes an orbiting scroll member and fixed scroll members, and has compression channels into which water is injected each formed between the intake port and exhaust port provided in the fixed scroll member. The oil-free scroll compressor includes temperature sensors each of which detects temperature in the compression channel, regulating valves each of which controls ratio of the amount of the water to be injected into the respective compression channels to the total amount of the water to be injected into the compression channels, and controller which controls the opening degrees of the regulating valves such that a difference between the detected temperatures from the compression channels is small.

Abstract: A conventional machine package faces problems concerned with costs, weight, etc. and also a problem of antinomy that an attempt to enhance the noise reducing performance increases the airflow resistance and then deteriorates the cooling performance. Providing a sound absorbing structure with the heat radiation performance ensured within a practical range and then with considerably improved noise reducing effect achieves a low-noise machine package with a downsized casing and a reduced cooling fan power.

Abstract: 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.

Abstract: 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.