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 or vacuum pump including: a casing having a cooling gas inlet and a cooling gas outlet for allowing a cooling gas to flow therethrough; a fan mounted at the cooling gas inlet, including a fan housing and configured to blow said cooling gas into said casing; a compression or vacuum chamber including a first housing, a process gas inlet and outlet for allowing a process gas to flow therethrough and at least one rotating element; a driving module including a second housing and at least one bearing for supporting said at least one rotating element; a silencer including a cover and configured to attenuate noise generated by the compressor or vacuum pump. The silencer includes a recess structure on its cover, configured to deflect the cooling gas flow from the fan towards the driving module.

A bush bearing having an outer lubricating layer, a manufacturing method therefor and a scroll compressor having same applied thereto, according to the present disclosure, includes a bush bearing comprising: a base member which has a cylindrical shape having no separated surfaces along the circumferential direction; and a lubricating member which is formed from a material having a lower rigidity and more excellent lubricity than the base member, and has a cylindrical shape having no separated surfaces along the circumferential direction by being integrally provided to the outer circumferential surface of the base member, wherein the cylindricity of the outer circumferential surface of the lubricating member satisfies a value that is within 0.6% of the average thickness of the lubricating member, and the lubricating member has carbon fiber contained in a resin base, wherein the carbon fiber has cut surfaces exposed on both ends of the lubricating member.

According to one embodiment, there is provided a motor-operated compressor comprising a rotation shaft, a first scroll configured to perform an orbiting motion and comprising an eccentric coupling portion eccentrically coupled to the rotation shaft, a second scroll coupled to the first scroll to form a pair of compression chambers, a rotor coupled to the rotation shaft, a stator forming an accommodation space configured to accommodate the rotor, and an eccentricity compensation portion configured to compensate for an eccentric displacement of a center of gravity of the rotation shaft, in response to the orbiting motion of the first scroll. The eccentricity compensation portion comprises a first member positioned on one end of the stator and a second member positioned on the rotor adjacent to the first member.

A compressor may include a non-orbiting scroll, an orbiting scroll, a bearing housing and first and second discrete keys. The non-orbiting scroll may include a first end plate having a first spiral wrap extending therefrom. The orbiting scroll may include a second end plate having a second spiral wrap extending therefrom and meshingly engaged with the first spiral wrap of the non-orbiting scroll. The bearing housing may support the orbiting scroll. Each of the first and second keys may be slidably engaged in first slots formed in the second end plate of the orbiting scroll and slidably engaged in second slots formed in the first end plate of the non-orbiting scroll or third slots formed in the bearing housing.

A leak detector is provided for leak-testing objects that are to be tested by spraying tracer gas, the leak detector including: a detection inlet configured to be connected to an object that is to be tested; a pumping device including a vacuum line connected to the detection inlet, a rough-vacuum pump connected to the vacuum line, and a turbomolecular vacuum pump connected to the vacuum line, a delivery of which is connected to the rough-vacuum pump; and a gas detector connected to the turbomolecular vacuum pump, the pumping device further including an ancillary pump connected to the rough-vacuum pump and being configured to lower an ultimate-vacuum pressure of tracer gas in the rough-vacuum pump. A leak detection method for leak-testing objects that are to be tested by spraying tracer gas is also provided.

A compressor includes a compression mechanism configured to suck and compress a refrigerant from a suction space to discharge the refrigerant to a discharge space by a driving force transmitted thereto. The compressor includes an oil storage chamber provided in the discharge space to collect oil separated from the refrigerant discharged from the compression mechanism, an oil recovery passage configured to guide the oil in the oil storage chamber to the suction space, and a decompression mechanism provided in the oil recovery passage to reduce a pressure of the oil passing through the oil recovery passage by an orifice hole having an inner diameter smaller than the oil recovery passage. The decompression mechanism is configured such that, when a pressure in the oil storage chamber is increased, the inner diameter of the orifice hole is reduced.

A compressor includes: a case including a discharge part configured to discharge refrigerant and defining a reservoir space configured to store oil; a drive unit including a stator and a rotor; a rotary shaft coupled to the rotor; a compression unit coupled to the rotary shaft and lubricated with oil, the compression unit being configured to compress refrigerant and discharge compressed refrigerant in a direction away from the discharge part; a muffler coupled to the compression unit and configured to guide refrigerant to the discharge part; a separator coupled to at least one of the rotor or the rotary shaft and configured to separate oil from refrigerant guided to the discharge part; and a coupling unit that fixes the separator to the at least one of the rotor or the rotary shaft.

A compressor is provided and may include a shell, a main bearing housing disposed within the shell, a driveshaft, a non-orbiting scroll member, and an orbiting scroll member. The driveshaft may be supported by the main bearing housing. The non-orbiting scroll member may be coupled to the main bearing housing and may include a first lubricant supply path in fluid communication with a lubricant source. The orbiting scroll member may be rotatably coupled to the driveshaft and may be meshingly engaged with the non-orbiting scroll member. The orbiting scroll member may include a recess that is moved between a first position in fluid communication with the first lubricant supply path and a second position fluidly isolated from the first lubricant supply path.

A scroll compressor that includes a rotating shaft, an eccentric bush having a recess, into which one end of the shaft is inserted, and an eccentric portion eccentric to the shaft, an orbiting scroll operatively connected to the eccentric portion for orbiting, a fixed scroll engaged with the orbiting scroll, and a buffer member interposed between the one end of the shaft and the recess. Therefore, it is possible to prevent damage to the scrolls due to liquid refrigerant compression during initial operation and to prevent an impact sound between the shaft and the eccentric bush due to the rotational clearance therebetween.