A compressor includes a casing that stores lubricant at a bottom, a compression mechanism disposed in the casing to suck and compress a refrigerant, and an oil return member forming an oil return flow path that extends in a top-to-bottom direction to guide the lubricant discharged from the compression mechanism downward. The oil return flow path includes a uniform-cross-section flow path, and a varying-cross-section flow path continuous with a lower end of the uniform-cross-section flow path. A lower end of the varying-cross-section flow path forms an outlet of the oil return flow path and lies along an inner surface of the casing. A the lower end of the varying-cross-section flow path has a greater width than an upper end of the varying-cross-section flow path, and the lower end of the varying-cross-section flow path has a smaller thickness than the upper end of the varying-cross-section flow path.

An air injection enthalpy-increasing scroll compressor is provided. The compressor has a main frame, a movable scroll plate and a stationary scroll plate. The movable scroll plate has a movable plate end plate and a movable scroll wrap arranged on a side end face of the movable plate end plate. A back pressure chamber is defined between the movable plate end plate and the main frame. The stationary scroll plate has a fixed scroll end plate and a stationary scroll wrap arranged on a side end face of the fixed scroll end plate. The stationary scroll wrap and the movable scroll wrap are engaged with each other to form a crescent-shaped compression cavity. The movable scroll plate and the stationary scroll plate are provided with medium pressure passages that, during the rotation of the movable scroll plate, communicate the compression cavity with the back pressure chamber.

A fluid compressor includes a case, a fixed scroll, an orbiting scroll, a motor, and at least one anti-rotation unit. The case is configured to form an external appearance thereof. The fixed scroll is fixed in the case. The orbiting scroll is engaged with the fixed scroll at one side of the fixed scroll, and performs partitioning of a compression chamber. The motor provides the orbiting scroll with drive power. The anti-rotation unit is coupled to a side surface of the orbiting scroll so as to prevent rotation of the orbiting scroll.

A scroll compressor includes a compressor housing, an orbiting scroll member, a non-orbiting scroll member, an economizer injection inlet, and a discharge outlet. The orbiting scroll member and the non-orbiting scroll member are disposed within the compressor housing. The orbiting scroll member and the non-orbiting scroll member are intermeshed thereby forming a compression chamber within the compressor housing. The non-orbiting scroll includes a plurality of compression inlet ports. An economizer injection inlet is formed through the compressor housing and in fluid communication with the compression chamber via the compression inlet ports. The discharge outlet is in fluid communication with the compression chamber.

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.

There is disclosed a scroll compressor according to the present disclosure in which a discharge port is formed at a central portion thereof, and a pair of two compression chambers continuously moving toward the discharge port are formed, and a plurality of bypass portions are formed at each interval along a movement path of each compression chamber in the both compression chambers, and compression gradients of the both compression chambers are formed to be different from each other, wherein when an interval between a bypass portion closest to the discharge port and another bypass portion adjacent to the bypass portion among the bypass portions of each compression chamber is defined as a first interval, respectively, a first interval of a second bypass portion belonging to a compression chamber having a relatively larger compression gradient is formed to be smaller than that of a first bypass portion belonging to the other compression chamber between the both compressor chambers.

A compression chamber includes the compression chamber partitioning member, an intermediate pressure chamber guides an intermediate pressure working fluid before injection to the compression chamber, and the intermediate pressure chamber and the compression chamber face each other with a compression chamber partitioning member interposed between the intermediate pressure chamber and the compression chamber. Further, the intermediate pressure chamber includes an intermediate pressure chamber inlet through which an intermediate pressure working fluid flows, an injection port inlet of an injection port through which the intermediate pressure working fluid is injected into the compression chamber, and a liquid reservoir formed at a position below the intermediate pressure chamber inlet, and the liquid reservoir is formed by the compression chamber partitioning member.

A plurality of scroll compressors with different fixed volume indexes are connected in fluid parallel circuit and configured to selectively operate to maximize isentropic efficiency at different condensing temperatures. Different quantities of scroll compressors of different volume indexes may be selected based upon typical climate or geographic location environmental conditions to attempt to maximize efficiency. A controller may selectively operate different combinations of the compressors of different volume indexes bases up load demands and condensing temperature conditions, which may be determined in a variety of ways.

A compressor may include a shell, first and second scrolls, a seal assembly, a modulation control chamber, and a modulation control valve. The first scroll may include a first end plate having a biasing passage extending therethrough. The seal assembly may isolate a discharge pressure region from a suction pressure region. The seal assembly and the first scroll may define an axial biasing chamber therebetween that communicates with the axial biasing chamber and a first pocket between the first and second scrolls. The modulation control chamber may be fluidly coupled with the biasing chamber by a first passage. The modulation control valve may be fluidly coupled with the modulation control chamber by a second passage and movable between a first position allowing communication between the second passage and the suction pressure region and a second position restricting communication between the second passage and the suction pressure region.

A method of manufacturing a two-piece counterweight for a scroll compressor is provided. The method includes molding an outer plate, and molding a base having a first opening configured to receive a scroll compressor drive shaft having a longitudinal axis. The method further includes configuring the base for assembly and attachment to the drive shaft. The method also includes attaching the outer plate to the base such that the outer plate is axially offset from the base. In a particular embodiment of this method, the base and outer plate are molded from powdered metal. In certain embodiments, the base and outer plate include one or more openings aligned to permit attachment by inserting a mechanical fastener through the aligned openings. In alternate embodiments, the base and outer plate are attached via brazing or welding.