The disclosure discloses a method and a device for controlling cylinder switching of a compressor, a unit and an air conditioning system. The method includes: determining whether the compressor needs to perform cylinder switching; if so, adjusting current operating frequency according to a system pressure difference so that both the adjusted operating frequency and the system pressure difference meet a cylinder switching condition of the compressor; and controlling the compressor to perform cylinder switching. At the moment, the system pressure difference and the operation frequency are stable, and would not interfere the compressor's maintaining of the single-cylinder or double-cylinder operation state, which guarantees the energy efficiency of the unit where the compressor is located, and improves the use experience of a user.

A compressor includes a low-pressure stage cylinder, a first high-pressure stage cylinder and a second high-pressure stage cylinder which are stacked, a partition is arranged between each two adjacent cylinders, the first and second high-pressure stage cylinders are both situated at a same side of the low-pressure stage cylinder or respectively situated at two sides of the low-pressure stage cylinder, the lower flange is situated below the low-pressure stage cylinder, the first high-pressure stage cylinder and the second high-pressure stage cylinder. A first sliding sheet is provided in the first high-pressure stage cylinder, a second sliding sheet is provided in the second high-pressure stage cylinder, and a third sliding sheet is provided in the low-pressure stage cylinder. The first and the second high-pressure stage cylinders are arranged in parallel, and the first and second high-pressure stage cylinders arranged in parallel are connected to the low-pressure stage cylinder in series.

A method and a device for controlling a capacity change of a compressor, and a smart home appliance. The method includes: determining whether a capacity of the compressor is required to be changed; if yes, determining an intermediate frequency; changing the capacity of the compressor while maintaining the operating frequency of the compressor at the intermediate frequency; and the maintaining the operating frequency of the compressor at the intermediate frequency reduces a sudden change in output of the compressor after the changing the capacity.

Provided is a variable-capacity mechanism for a scroll compressor. The scroll compressor includes a compression mechanism. The compression mechanism includes a fixed scroll and an orbiting scroll for defining a series of compression cavities. The variable-capacity mechanism includes: a discharge channel, suitable for communicating a medium-pressure compression cavity in the compression cavities with a low-pressure region; blocking members, suitable for selectively opening or closing the discharge channel; an actuation device, including an execution member, the blocking members being connected to the execution member so as to selectively open or close the discharge channel along with the actions of the execution member. Multiple blocking members are connected to a single execution member so as to synchronously move along with the actions of the single execution member. By the variable-capacity mechanism, action synchronization of multiple blocking members can be reliably implemented. Provided is a scroll compressor including the variable-capacity mechanism.

Disclosed are a compressor, an air conditioner and a method for assembling a compressor, wherein the compressor includes a housing, a first cylinder assembly and a second cylinder assembly. The first cylinder assembly includes a first cylinder. The first cylinder assembly has a first discharge channel. A first end of the first discharge channel is in communication with the first cylinder, a second end of the first discharge channel is in communication with a receiving chamber. The second cylinder assembly includes a second cylinder; the second cylinder is disposed adjacent to the first cylinder. The second cylinder assembly has a second discharge channel which is disposed relatively independent of the first discharge channel. A first end of the second discharge channel is connected to the second cylinder; a second end of the second discharge channel is in communication with a receiving chamber.

A system may include a first compressor, a second compressor, a first heat exchanger and a second heat exchanger. The first compressor has a first inlet and a first outlet. The second compressor is a sumpless compressor and has a second inlet and a second outlet. The second compressor provides working fluid discharged from the second outlet to the first compressor. The first heat exchanger is disposed upstream of the second compressor and provides working fluid to the second compressor. The second heat exchanger is disposed upstream of the first compressor and provides working fluid to the first compressor.

Systems and methods for providing lubricant from a first compressor to a second compressor are provided. A control module receives a start command for a climate-control system having the first and second compressors, allows lubricant from the first compressor to flow into an inlet of the second compressor, turns the second compressor to an ON-mode, and prevents lubricant from the first compressor from flowing into the inlet of the second compressor after the second compressor has been in the ON-mode for a predetermined time period.

A vacuum pump structure includes a motor, two pump bodies, and a grip. The two pump bodies are connected to the motor and driven by the motor, respectively. Each pump body has a pump chamber with a connection port for connecting a suction pipe. The grip has two ends respectively connected to the two pump bodies for carrying the vacuum pump structure. A communication pipe is disposed inside the grip. The communication pipe is in communication with the pump chambers of the two pump bodies. The two pump bodies jointly perform two working modes at the same time to improve work efficiency.

An improved compressed air system utilizes one or more base compressors, such as fixed speed drive compressors, to meet the compressed air demands and one or more trim compressors, such as variable speed drive compressors, to meet the variations in the demand. The operation of both the base and trim compressors may be controlled to provide improved overall efficiency while meeting the transient load demands. The control may spread the demands over the various base compressors to improve the overall loading on each base compressor. Efficiency metrics may be utilized to control the switching between base and trim compressors. Unloading of a base compressor may be controlled to avoid undesirable changes in system performance.

The present disclosure relates to a variable-capacity compressor (100) and a refrigeration device (200). The variable-capacity compressor (100) comprises a housing (1), a compression mechanism, two first suction conduits (61) and a variable-capacity valve (3); the compression mechanism comprises two bearings (21, 22) and a cylinder assembly, the cylinder assembly comprises a first cylinder (23) and a second cylinder (24), at least one of the first cylinder (23) and the second cylinder (24) is configured as a variable-capacity cylinder, and a compression chamber (28) and a suction port (A) is formed in the variable-capacity cylinder; the variable-capacity valve (3) is disposed in the compression mechanism and configured to be movable between a communication position and an isolation position, wherein the variable-capacity cylinder operates when the variable-capacity valve (3) is located in the communication position, and the variable-capacity cylinder is unloaded when the variable-capacity valve (3) is located the isolation position.