A multi-stage dry Roots vacuum pump, including a pump body, multi-stage Roots working units and a plurality of drive components. The pump body is provided with a plurality of independent working chambers, and airflow channels communicating the various working chambers; the airflow channels are communicated with outside; the Roots working units of each stage include driving Roots rotors and driven Roots rotors; the driving Roots rotors and driven Roots rotors are positioned in the working chambers; and the various drive components are respectively used for driving the driving Roots rotors and driven Roots rotors positioned in the various working chambers to rotate towards opposite directions at the same rotating speed. The Roots working units of various stages may be randomly distributed at various positions of the pump body on premise of ensuring that the airflow channels can communicate the working chambers of each stage.

A cooling system is configured to operate in one of three modes, a DX mode of operation when outdoor air is too hot or too humid and the cooling system operates as a normal closed circuit system, a hybrid mode of operation when outside temperatures cool down and the cooling system operates as a partial reduced normal closed circuit system and a free cooling system, and a thermosiphon mode of operation when the outside temperature is below a predetermined temperature and the cooling system operates without the normal closed circuit system. The cooling system includes a scroll compressor unit having a main casing, a scroll compressor supported by the main casing, and a refrigerant pump supported by the main casing. The scroll compressor unit is configured to selectively engage the scroll compressor and the refrigerant pump to achieve one of the DX mode, the hybrid mode, and the thermosiphon mode.

A rotary compressor includes a cylinder that is coupled to an inner space of a casing and that defines a compression space, a first bearing and a second bearing located at upper and lower sides of the cylinder, a roller disposed eccentrically with respect to an inner circumferential surface of the cylinder to vary a volume of the compression space based on rotation, and a vane inserted into the roller to rotate together with the roller, and drawn out toward the inner circumferential surface of the cylinder during the rotation of the roller to partition the compression space into a plurality of compression chambers. A suction passage communicating with the compression space is defined in the first bearing or the second bearing, and a suction port communicating between the suction passage and the compression space is defined on a side surface of the cylinder.

A refrigeration system includes a compressor having a hermetically sealed housing and a compression mechanism which is positioned inside the housing; a condenser which is fluidly connected to the compressor; an evaporator which is fluidly connected between the condenser and the compressor; a magnetic coupling having a drive coupling half positioned outside the housing and a driven coupling half positioned inside the housing and separated from the drive coupling half by a separation wall portion of the housing; and a fluid conduit for communicating a portion of liquid refrigerant from the condenser to an inside surface of the separation wall portion. During operation, the liquid refrigerant from the condenser is evaporated on or adjacent the inside surface of the separation wall portion to thereby dissipate heat generated by magnetically induced eddy currents in the separation wall portion.

The present disclosure provides a motor part comprising a bobbin part comprising a plurality of coils housed therein, a first insulation part adjacent to an inner circumferential surface of the motor chamber, and a second insulation part spaced a predetermined distance from the first insulation part. The plurality of coils are housed in a coil housing spare part formed between the first insulation part and the second insulation part. The first insulation part is located between the inner circumferential surface of the motor chamber and the plurality of coils. The plurality of coils are located adjacent to the second insulation part. Accordingly, insulation caused by separation from the inner circumferential surface of the motor chamber and insulation caused by the first insulation part may be expected. The insulation may be achieved by the plurality of coils being housed in the bobbin part.

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 screw compressor (12) includes a casing (20) having a suction port and a discharge port, a male rotor (28) rotatable relative to said casing about a first axis (A), a female rotor (30) rotatable relative to said casing about a second axis (B), and a magnetic gear system including a first magnetic gear (60) associated with said male rotor and a second magnetic gear (62) associated with said female rotor. The first magnetic gear and the second magnetic gear are positioned such that a magnetic field of said first magnetic gear interacts with said second magnetic gear to drive rotation of said female rotor about said second axis.

A pump includes a housing, a drive shaft, a centrifugal pump portion having an impeller, and a gear pump portion having first and second gears. The impeller and one of the first and second gears are mounted to the drive shaft to drive the centrifugal pump portion and the gear pump portion at the same rotational speed. The gear pump can be a crescent internal gear (CIG) pump. The drive shaft can be rotated by a magnetic drive. The drive shaft can include a longitudinal bore in fluid communication with a cavity in the magnetic drive and with a discharge of the centrifugal pump portion to circulate working fluid through the magnetic drive to cool the drive. An impeller can be coupled to an inlet of the centrifugal pump portion.

A method and system is provided for pressure balancing one or more seals in machines such as expanders and/or compressors using the process fluid which is being expanded or compressed to provide the pressure for pressure balancing the other side of the one or more seals. The one or more seals may be part of a pressure containing chamber which may comprise a seal, a bearing and/or a gear on a rotating shaft common to the seal. An amount of pressure to be supplied to housing(s) for a machine so as to create a pressure cascade, and thereby dropping the pressure in each subsequent chamber as pressure approaches atmosphere. Pressure differentials may be directed to leak process fluid to the chamber into the process. Pressurized lube oil systems may be employed for balancing pressure and delivering lubricant to the seals, bearings and gears.

A scroll device has a housing having a fixed scroll plate and an orbiting scroll plate mounted therein on an idler shaft, the fixed scroll plate having a side having a fixed interleaved involute scroll and an outward facing side, the orbiting scroll plate having a side that has an orbiting interleaved involute scroll, an inlet port for the introduction of a working fluid into the device, and a pressure plate positioned adjacent to the outward facing side of the fixed scroll plate.