A welding machine includes a welding power supply that generates a welding waveform during a welding operation, an internal combustion engine, and a generator that is operatively connected to the welding power supply to supply electrical energy to the welding power supply. The generator includes a rotor shaft driven by the internal combustion engine, and an end casting located at an end of the generator opposite the internal combustion engine. A rotary screw compressor is mounted to the end casting of the generator. A clutch mechanism couples the rotor shaft to the rotary screw compressor to selectively drive the rotary screw compressor by the rotor shaft.

Power systems and methods of controlling an engine driven air compressor include an air compressor driven by an engine via a clutch. A first pressure sensor configured to sense a pressure level at an outlet of the air compressor. An inlet valve configured to close in response to the first pressure sensor sensing a pressure level above a first pressure level. In addition, a second pressure sensor to sense a pressure level below a second pressure level at a housing of the air compressor, wherein the clutch is configured to disengage in response to the second pressure level, wherein the first pressure level is higher than the second pressure level.

A screw compressor of the present invention comprises: a housing having a compression chamber; male and female rotors provided in the compression chamber; a driving shaft for rotating the male and female rotors; and a seal cover across which the driving shaft is provided, and further includes: an oil chamber provided at the seal cover, and returning, to the compression chamber, oil having leaked into the driving shaft; and a breather for injecting external air into the oil chamber. Therefore, the breather is provided at the upper part of the oil chamber and an oil recovery line is provided at the lower part thereof so as to cause a pressure difference between the upper and lower parts of the oil chamber, such that the flow of the oil having leaked into the driving shaft is smoothly recovered in the oil recovery line.

A preheating heat exchanger allows heat exchange between cooling water on an outlet side of an auxiliary cooling heat exchanger and supply water that has passed through a preheating bypass path.

In the operation of a refueling screw compressor, when load conditions constantly fluctuate or when the rotation speed control of a cooling fan is performed, it is difficult to accurately perform a diagnosis predicted from measurement results of devices inside the compressor, so a diagnostic mode stably creates an operating condition under which an accurate diagnosis can be performed. In the refueling screw compressor, a discharge electric valve is provided downstream of an air cooler, and an air release electric valve and a dedicated orifice are provided to connect an oil separator inner space and a suction throttle valve space. In the diagnostic mode, the discharge electric valve is closed, the air release electric valve is opened, and while an upstream pressure of the oil separator is maintained at a specified pressure, a rotation speed control operation of a compressor body and the diagnosis of internal devices are performed.

A vibration suppressing piping member suppresses vibration caused by a pulsating discharged gaseous fluid. The piping member includes a tubular portion and flange portions at both ends of the tubular portion. A bent portion is formed between the two flange portions. The two flange portions are directly connected to each other.

A lubrication system is provided for supplying lubricant to an air compressor. The air compressor is driven by a drive system. The lubrication system includes a reservoir configured to support lubricant and configured to receive pressurized air from the air compressor, the separator reservoir configured to separate lubricant from the air received from the air compressor; and a motor operably coupled to the drive system and configured to receive pressurized lubricant. The motor is configured to transmit power to the drive system in at least one operating condition.

A vacuum system having a condenser and a root vacuum pump set includes an independent inlet condenser set having an inlet end for receiving vapor inputted from an output of an air cooling power generator condenser of a generator; air in the vapor being condensed, and the surplus air is outputted; a root vacuum pump set including a plurality of root vacuum pumps; the root vacuum pump set further including an input end and an output end; the input end being connected to the independent inlet condenser set; air outputted from the independent inlet condenser set being inputted to the plurality of root vacuum pump for compression and then the compressed air being outputted from the output end; and a backing pump connected to the output end of the root vacuum pump set by using an output pipe; the backing pump serving to receive air outputted from the root vacuum pump set.

The present disclosure is directed to a screw compressor system having a compressor housing with a pair of screw rotors rotatably supported within a compression chamber. Lubricant is injected into a compression chamber at a first volume ratio and at a second volume ratio greater than the first volume ratio to increase the sealing and lubrication between the screw rotors and rotor bores in the compressor housing as well as to increase heat transfer from a compressed working fluid in the compression chamber.

The present disclosure is related to a slide valve, a slide valve adjustment mechanism and a screw compressor. The slide valve includes a static slide valve and a moving slide valve, wherein the static slide valve is fixedly installed in a slide valve cavity and provided with an axially-penetrating valve hole; a plurality of bypass holes communicating with the valve hole (110) are formed in the sidewall of the static slide valve, and an exhaust port is formed in the sidewall of one end of the static slide valve. The slide valve may avoid scraping between the slide valve and a screw rotor and the slide valve cavity. Gaps between the slide valve and parts which cooperate with same are reduced, so that the leakage is reduced while the energy efficiency of the compressor is increased.