A technique is provided that can further reduce power at the time of unload operation control in a gas compressor that generates a compressed gas at a set pressure by constant-speed control. The gas compressor includes a compressor main unit, a drive source, an intake throttle valve, a gas release valve, rotation speed converting means, a pressure detecting device that detects a discharge pressure, and a controller that, the relationship between an upper-limit pressure H and a lower-limit pressure L being H>L, carries out opening the intake throttle valve and closing the gas release valve and operating the drive source at a full-load rotation speed until the discharge pressure reaches the upper-limit pressure H. The controller carries out at least one of closing the intake throttle valve and opening the gas release valve to reduce the discharge pressure to within a predetermined range when the discharge pressure reaches the upper-limit pressure H. The controller carries out switching to load operation when the discharge pressure drops to the lower-limit pressure L. In the gas compressor, the controller outputs a command of a lower rotation speed than the full-load rotation speed to the rotation speed converting means when the discharge pressure rises and reaches the upper-limit pressure H. The controller outputs a command of the full-load rotation speed to the rotation speed converting means when the discharge pressure drops and reaches the lower-limit pressure L.

A scroll compressor with a first valve having a first surface to open/close between a first path and a second path; a back pressure chamber assembly or non-orbiting scroll having a third path through which a first pressure refrigerant flows, a fourth path through which refrigerant of a second pressure lower than the first pressure flows, and one end in communication with the third and fourth paths and the other end having a fifth path in communication with a second surface of the first valve; and a second valve provided where the third, fourth, and fifth paths meet and moveable between first and second positions, wherein at the first position the third and fifth paths communicate to supply the first pressure refrigerant toward the second surface, and at the second position the fourth and fifth paths communicate to supply the second pressure refrigerant toward the second surface.

A scroll compressor with a first valve having a first surface to open/close between a first path and a second path; a back pressure chamber assembly or non-orbiting scroll having a third path through which a first pressure refrigerant flows, a fourth path through which refrigerant of a second pressure lower than the first pressure flows, and one end in communication with the third and fourth paths and the other end having a fifth path in communication with a second surface of the first valve; and a second valve provided where the third, fourth, and fifth paths meet and moveable between first and second positions, wherein at the first position the third and fifth paths communicate to supply the first pressure refrigerant toward the second surface, and at the second position the fourth and fifth paths communicate to supply the second pressure refrigerant toward the second surface.

A scroll compressor, and more particularly, to a scroll compressor including a communication groove which may decrease discharge resistance is provided. The scroll compressor may include a fixed scroll having a fixed end plate and a fixed wrap, and an orbiting scroll configured to perform an orbiting movement about the fixed scroll and having an orbiting end plate and an orbiting wrap. A communication groove in the form of a recessed groove may be formed in an inner surface of the orbiting end plate, and a refrigerant may flow through the communication groove according to a state in which the fixed wrap overlaps the communication groove such that there is an effect in that an opening efficiency of a discharge hole is improved at an initial stage of discharge.

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.

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.

A supercharger having twisted meshing rotors sealingly contained within a housing having an inlet port to admit air into the meshing rotors and an outlet port to expel air from the meshing rotors, the rotors having mesh points where the rotors contact one another and spaces between their mesh points to accept air from the inlet port and propel it to the outlet port as the rotors are rotated and the mesh points travel axially, the housing, inlet and rotors defining an angle known as the seal transfer angle which is greater than or equal to zero degrees when the inlet port is closed and the volume of air between rotors is sealed and has no leakage path. In the described supercharger the housing, rotors and inlet port are configured to have a negative seal transfer angle of, e.g., 10 to 40 degrees or more, up to the maximum available, and to provide a leakage path for an angular portion of the rotors' rotation, improving high end performance without degrading low end performance

A compressor may include first and second scrolls, and an axial biasing chamber. Spiral wraps of the scrolls mesh with each other and form compression pockets including a suction-pressure compression pocket, a discharge-pressure compression pocket, and intermediate-pressure compression pockets. The axial biasing chamber may be disposed axially between the second end plate and a component. Working fluid disposed within the axial biasing chamber may axially bias the second scroll toward the first scroll. The second end plate includes outer and inner ports. The outer port is disposed radially outward relative to the inner port. The outer port may be open to a first one of the intermediate-pressure compression pockets and in selective fluid communication with the axial biasing chamber. The inner port may be open to a second one of the intermediate-pressure compression pockets and in selective fluid communication with the axial biasing chamber.

A compressor may include first and second scrolls, and an axial biasing chamber. Spiral wraps of the scrolls mesh with each other and form compression pockets including a suction-pressure compression pocket, a discharge-pressure compression pocket, and intermediate-pressure compression pockets. The axial biasing chamber may be disposed axially between the second end plate and a component. Working fluid disposed within the axial biasing chamber may axially bias the second scroll toward the first scroll. The second end plate includes outer and inner ports. The outer port is disposed radially outward relative to the inner port. The outer port may be open to a first one of the intermediate-pressure compression pockets and in selective fluid communication with the axial biasing chamber. The inner port may be open to a second one of the intermediate-pressure compression pockets and in selective fluid communication with the axial biasing chamber.

A scroll compressor according to the present invention includes a casing having a hermetic inner space divided into a low pressure portion and a high pressure portion, an orbiting scroll disposed within the inner space of the casing and performing an orbiting motion, a non-orbiting scroll forming a compression chamber together with the orbiting scroll, the compression chamber having a suction chamber, an intermediate pressure chamber and a discharge chamber, a back pressure chamber assembly coupled to the non-orbiting scroll to form a back pressure chamber, a valve accommodation groove formed on at least one of the non-orbiting scroll or the back pressure chamber assembly, a bypass hole formed from the intermediate pressure chamber into the valve accommodation groove in a penetrating manner, a check valve accommodated in the valve accommodation groove and opening and closing the bypass hole according to pressure of the intermediate pressure chamber, a communication passage communicating the valve accommodation groove and the low pressure portion with each other, and a control valve selectively opening and closing the communication passage, whereby a facilitated fabrication, improved responsiveness and relaxed restriction for a specification of a valve can be achieved.