A scroll compressor according to the present invention includes a partition plate that partitions a sealed container into a high-pressure space and a low-pressure space, a fixed scroll adjacent to the partition plate, a orbiting scroll, a rotation restrictor, and a main bearing. The sealed scroll compressor further includes a pillar member having a lower end portion secured in a bearing-side engagement portion provided in the main bearing, and an upper end portion inserted in a scroll-side engagement portion provided in the fixed scroll. The axial distance from the upper end portion of the pillar member to the partition plate is smaller than the length by which the pillar member and the bearing-side engagement portion are coupled together.

A device for compression of a gaseous fluid, in particular of a refrigerant. The device comprises a housing with a suction pressure chamber and a high pressure chamber, a compression mechanism as well as a configuration developed in the proximity of the high pressure chamber, for the separation of a control mass flow from a fluid-lubricant mixture for the control of the compression mechanism. The configuration is developed and disposed with a first flow duct for diverting a main mass flow of the compressed fluid-lubricant mixture from the device and a second flow duct for conducting the control mass flow within the device to the suction pressure chamber in such manner as to separate a mass flow of the gaseous fluid as a control mass flow. A method for the separation of a control mass flow is also provided.

A positive displacement device includes a first cylinder, a second cylinder disposed within the first cylinder, and a third cylinder disposed around the first cylinder. An interior surface of the first cylinder and an exterior surface of the second cylinder define an inner cavity. An exterior surface of the first cylinder and an interior surface of the third cylinder define an outer cavity. A partition between the interior surface of the first cylinder and the exterior surface of the second cylinder divides the inner cavity into inner regions, and another partition between the exterior surface of the first cylinder and the interior surface of the third cylinder divides the outer cavity into outer regions. The second cylinder and the third cylinder orbit with respect to the first cylinder to create alternating regions of high pressure and low pressure in the inner regions and the outer regions.

A positive displacement device includes a first cylinder, a second cylinder disposed within the first cylinder, and a third cylinder disposed around the first cylinder. An interior surface of the first cylinder and an exterior surface of the second cylinder define an inner cavity. An exterior surface of the first cylinder and an interior surface of the third cylinder define an outer cavity. A partition between the interior surface of the first cylinder and the exterior surface of the second cylinder divides the inner cavity into inner regions, and another partition between the exterior surface of the first cylinder and the interior surface of the third cylinder divides the outer cavity into outer regions. The second cylinder and the third cylinder orbit with respect to the first cylinder to create alternating regions of high pressure and low pressure in the inner regions and the outer regions.

A multistage compressor system with intercooler can include a sealed housing with first and second compressor stages, where the first compressor stage is for receiving refrigerant from outside of the sealed housing, and the second compressor stage is for receiving refrigerant from within the sealed housing. The compressor system can also include a crank for mechanically driving the first compressor stage and/or the second compressor stage, and a heat exchanger outside of the sealed housing for receiving refrigerant from the first compressor stage and exchanging heat with the refrigerant. The compressor system can further include an oil reservoir contained by the sealed housing, where the oil reservoir includes oil for lubricating the crank, receives the refrigerant from the heat exchanger, and exchanges heat with the refrigerant to cool the oil in the oil reservoir, and where the refrigerant can be supplied to the second compressor stage.