Disclosed herein is a rotary compressor capable of maintaining the overall dynamic balance and providing low vibration and low noise even at high speed operation and capable of improving efficiency by providing a communication passage to communicate operation chambers, which are provided inside each of the plurality of cylinders for compressing a refrigerant, to each other. The rotary-type compressor includes a housing, a drive motor provided inside the housing to generate power and having a stator and a rotor, and a compression unit that receives power from the drive motor and compresses the refrigerant. The compression unit includes a plurality of cylinders in which an operation chamber to compress the refrigerant is provided. The operation chambers provided in each of the plurality of cylinders are provided to have different volumes, and a balancer provided to maintain dynamic balance is provided only in the lower side of the rotor.

In a cylinder rotary compressor, a shaft-side suction passage for circulation of a refrigerant is formed within a shaft that rotatably supports a rotor. A rotor-side suction passage is provided within the rotor so as to guide the refrigerant flowing out of shaft-side outlets formed at the outer peripheral surface of the shaft to a compression chamber. Furthermore, a rotor-side concave portion is formed at an inner peripheral surface of the rotor. A space provided within the rotor-side concave portion forms a rotor-side communication space with an appropriate shape and a capacity enough to make the shaft-side outlets communicate with a rotor-side inlet of the rotor-side suction passage, regardless of the rotation of the rotor.

A rotor has at its two axis end portions an upper large-diameter inner circumferential portion and a lower large-diameter inner circumferential portion that have inner diameters larger than the inner diameter of the axially middle portion of the rotor and are offset in the radial direction. A crankshaft has a passageway, which is formed in the crankshaft and allows refrigerant to flow therethrough, and a gas venting hole, which provides communication between the passageway and at least one discharge opening formed in the outer circumferential surface of the crankshaft. The at least one discharge opening is formed at a position facing the inner circumferential surface of the lower large-diameter inner circumferential portion 5b on the compression unit side.

A rotor has at its two axis end portions an upper large-diameter inner circumferential portion and a lower large-diameter inner circumferential portion that have inner diameters larger than the inner diameter of the axially middle portion of the rotor and are offset in the radial direction. A crankshaft has a passageway, which is formed in the crankshaft and allows refrigerant to flow therethrough, and a gas venting hole, which provides communication between the passageway and at least one discharge opening formed in the outer circumferential surface of the crankshaft. The at least one discharge opening is formed at a position facing the inner circumferential surface of the lower large-diameter inner circumferential portion 5b on the compression unit side.

A scroll compressor is disclosed, which comprises an auxiliary discharge path capable of sufficiently making sure of a discharge area at an initial discharge stage. The compressor comprises a fixed scroll including a fixed end plate portion and a fixed wrap, and an orbiting scroll including an orbiting end plate portion and an orbiting wrap, wherein a discharge hole is formed in the fixed end plate portion, and an auxiliary discharge path for connecting a side of the orbiting wrap with a bottom surface of the orbiting wrap is provided to be communicated with the discharge hole, whereby a compressed refrigerant may be discharged through the auxiliary discharge path.

A scroll compressor is disclosed, which comprises an auxiliary discharge path capable of sufficiently making sure of a discharge area at an initial discharge stage. The compressor comprises a fixed scroll including a fixed end plate portion and a fixed wrap, and an orbiting scroll including an orbiting end plate portion and an orbiting wrap, wherein a discharge hole is formed in the fixed end plate portion, and an auxiliary discharge path for connecting a side of the orbiting wrap with a bottom surface of the orbiting wrap is provided to be communicated with the discharge hole, whereby a compressed refrigerant may be discharged through the auxiliary discharge path.

A compressor system includes: a first compressor including a first casing having a cylindrical shape, and a first bundle capable of being inserted into and pulled out from the first casing in an axial direction of the first casing; and a second compressor including a second casing having a cylindrical shape, and a second bundle capable of being inserted into and pulled out from the second casing in an axial direction of the second casing. The first and second compressors are arranged to face each other to cause pullout directions of the respective bundles to be opposite to each other. A maintenance space shareable for insertion and pullout operations of the first bundle and insertion and pullout operations of the second bundle is interposed between the first bundle and the second bundle, and is available for the bundle under the insertion and pullout operations.

In an outer circumferential portion of an intermediate partition plate, a concave portion is provided at a position at which an upper vane and a lower vane slide. At a lower dead center of an upper piston and a lower piston, 80% or more of the entire length in the sliding direction of the upper vane and the lower vane are accommodated respectively on the inside of an upper cylinder and the inside of a lower cylinder. In the concave portion, a width W with respect the circumferential direction of the intermediate partition plate is greater than a thickness T of the upper vane and the lower vane, and when a depth of the concave portion is D and the entire length of the upper vane and the lower vane is L, D≧0.1×L is satisfied.

A submersible fuel oil apparatus includes a base; at least one platform supported above the base and having a top surface, an underside surface and an aperture therethrough; a submersible motor mounted on the top surface of the platform and having a motor shaft extending vertically downward through the aperture in the platform; a fuel oil pump supported underneath the platform and having a pump shaft extending vertically upward, a pump inlet into which fuel oil is adapted to be delivered, and a pump outlet from which fuel oil is adapted to be pumped, the pump positioned such that the motor shaft and the pump shaft are aligned; a coupler connecting the motor shaft and pump shaft to each other; inlet piping connected to the pump inlet; and outlet piping connected to the pump outlet.

A submersible fuel oil apparatus includes a base; at least one platform supported above the base and having a top surface, an underside surface and an aperture therethrough; a submersible motor mounted on the top surface of the platform and having a motor shaft extending vertically downward through the aperture in the platform; a fuel oil pump supported underneath the platform and having a pump shaft extending vertically upward, a pump inlet into which fuel oil is adapted to be delivered, and a pump outlet from which fuel oil is adapted to be pumped, the pump positioned such that the motor shaft and the pump shaft are aligned; a coupler connecting the motor shaft and pump shaft to each other; inlet piping connected to the pump inlet; and outlet piping connected to the pump outlet.