A method of operating a multiple-compressor refrigeration system is provided. This method includes the steps of supplying, via a common supply line, refrigerant gas and oil to a plurality of compressors coupled in series, and attaching an oil flow conduit between adjacent compressors of the plurality of compressors. The oil flow conduit is configured to move oil from a compressor with a relatively higher pressure to a compressor with a relatively lower pressure. The method further includes controlling the pressure for each of the plurality of compressors by regulating a speed at which each of the plurality of compressors operates in order to maintain a pressure differential between the adjacent compressors to facilitate the flow of oil from the compressor with the relatively higher pressure to the compressor with the relatively lower pressure.

A compressor includes a casing configured to accommodate refrigerant and oil, a discharger disposed at a side of the casing and configured to discharge the refrigerant, a driver including a stator and a rotor, a rotation shaft that is coupled to the rotor and that extends in a direction away from the discharger, a compressing assembly that is coupled to the rotation shaft, that is configured to be lubricated with the oil, and that is configured to compress the refrigerant and discharge the compressed refrigerant in the direction away from the discharger, a muffler coupled to the compressing assembly and configured to guide the refrigerant to the discharger, and a bypassing portion disposed outside the casing and configured to transfer the refrigerant or the oil from the muffler to the discharger.

Disclosed is a compressor including a compressing assembly having a decompressing structure to control an amount of oil. The decompressing structure is oriented in parallel with a length direction of the rotation shaft or in a direction toward a discharger from which the refrigerant is discharged.

The present disclosure provides a compressor system having at least one fluid compressor for compressing a working fluid. A lubrication supply system is operable for supplying lubrication fluid to the compressor. A closed loop cooling system using R718 refrigerant is provided to cool the working fluid. The closed loop cooling system includes a refrigerant compressor for compressing the refrigerant, a condenser operable for receiving compressed refrigerant gas and removing heat to form liquid refrigerant, and an expansion device for expanding and cooling the liquid refrigerant into a cooled gaseous refrigerant.

A scroll compressor lubrication system and a scroll compressor are disclosed. The scroll compressor includes a capacity modulator, a lubricant opening, and a gas diverting passage. The capacity modulator is in fluid communication with compression pockets for selectively unloading gas from the pockets. The lubricant opening is in fluid communication with at least one bearing portion of the scroll compressor. Lubricant from the at least one bearing portion in the scroll compressor flows through the lubricant opening. The gas diverting passage includes an inlet and an outlet. The inlet of the gas diverting passage is in fluid communication with the capacity modulator, and the gas diverting passage extends below the lubricant opening such that gas from the outlet of the gas diverting passage can flow through a travel path of the lubricant that flows through the lubricant opening and entrains at least part of the lubricant to at least one bearing portion for lubrication.

An internal gear pump for forward and reverse operations, comprising: a pump housing (2) which comprises a first fluid port (21) and a second fluid port (22), wherein in a first rotational direction, the first fluid port (21) is formed as a fluid outlet and the second fluid port (22) is formed as a fluid inlet, and in a second rotational direction, the first fluid port (21) is formed as a fluid inlet and the second fluid port (22) is formed as a fluid outlet; an internal gear (4) and an external gear (5) which together form delivery cells (3) in order to deliver a fluid; a first rotary bearing (D1) which mounts the internal gear (4); and a second rotary bearing (D2) which mounts the external gear (5); and comprising a lubricant feed which sets a fluid flow between the fluid ports (21, 22) through the two rotary bearings (D1, D2) in both rotational directions.

The present invention provides an oil feed type air compressor that can reduce a power consumption of a compressor body during an unload operation. The oil feed type air compressor includes: a compressor body (1) compressing air while feeding an oil into a compression chamber; a separator (4) disposed on a discharge side of the compressor body; a compressed air-feeding system (5) feeding the compressed air separated by the separator to a use destination of the compressed air; an oil-feeding system (6) feeding the oil separated by the separator to the compression chamber of the compressor body; an oil cooler (11) and a temperature sensor (12) disposed in the oil-feeding system; and a controller enabling execution of a temperature control. The temperature control by the controller is performed by variably controlling a rotation speed of a cooling fan (13) such that, during the load operation, a temperature detected by the temperature sensor is a target value T1, and during the unload operation, the temperature detected by the temperature sensor is a target value T2 (with the proviso of T1>T2).

The present disclosure provides a compressor system operable for compressing a working fluid such as air. A conditioner is positioned upstream of the compressor to reduce the humidity and in some embodiments may control a temperature of the working fluid entering the compressor. A working fluid aftercooler and a lubricant cooler is positioned downstream of the compressor. A first heat exchange system directs water from a source through the conditioner and then to the aftercooler and oil cooler in parallel. A second heat exchange system directs oil from the compressor to the oil cooler and then to a regenerator prior to reentry into the compressor. A control system with one or more control valves is configured to provide oil to the compressor at a target temperature defined to ensure that the temperature of the discharged compressor is above a pressure dew point temperature.

The present disclosure provides a compressor with an oil equalizing pipe, a parallel compressor set, and an oil equalizing method. The compressor includes at least one oil equalizing pipe, an opening at one end of the oil equalizing pipe is formed in a target oil level of an oil sump, and the opening at the other end of the oil equalizing pipe is formed in a suction port; and when the oil level of the oil sump of the compressor is higher than the target oil level, the extra oil enters the suction port through the oil equalizing pipe. Compared with the prior art, the present disclosure has the advantages that, when the compressor is running, the gas in the suction port flows, so that the pressure at the suction port is less than the pressure on the surface of the oil sump; when the oil level of the oil sump of the compressor is higher than the target oil level, the extra oil enters the suction port through the oil equalizing pipe under the action of the above pressure difference, a part of the oil enters vortex and is discharged from the compressor via the exhaust port, and the oil discharged from the compressor returns to the other compressor lack of oil through a pipeline, thereby achieving oil balance between different compressors.

A scroll compressor is provided which includes: a revolving scroll, a fixed scroll, an autorotation preventing mechanism, a frame, a crank shaft provided with an eccentric pin portion which is eccentric with respect to an axis, the crank shaft being provided with a flange portion at a lower portion of the eccentric pin portion, the flange portion being larger than the diameter of the eccentric pin portion, a balance weight mounted on the flange portion, a sealing member performing sealing between the revolving scroll and the flange portion, and a thrust bearing arranged between the frame and the flange portion. The scroll compressor reduces the amount of oil flowing into a back pressure chamber, thereby improving the performance of the scroll compressor.