A screw compressor, method of operating, and refrigerant circuit are disclosed. The screw compressor includes a suction inlet that receives a working fluid to be compressed. A compression mechanism is fluidly connected to the suction inlet that compresses the working fluid. A discharge outlet is fluidly connected to the compression mechanism that outputs the working fluid following compression by the compression mechanism. A valve assembly is configured to vary a location at which the compression mechanism compresses the working fluid, the valve assembly being disposed to modify a suction location of the screw compressor.

A vane pump including: a housing having a pump chamber; a rotor having a cylindrical peripheral wall portion accommodated in the pump chamber and having a pair of vane holding grooves facing each other in a diameter direction, and an oil chamber defined inside the peripheral wall portion to store lubricating oil; and a vane that is held in the pair of vane holding grooves and moves across the oil chamber in the diameter direction, is provided. At least one of an inner surface of the housing and an end face of the peripheral wall portion, which together with the inner surface defines a sliding interface, has an oil groove for the lubricating oil.

A scroll compressor includes a discharge port at a central portion, and a pair of scrolls that define two compression chambers continuously moving toward the discharge port, and a plurality of bypass portions defined at with an each interval along a compression path of each compression chamber. Compression gradients of the both compression chambers are different from each other. An interval between a bypass portion closest to the discharge port and another bypass portion is defined as a first interval. The first interval of a the bypass portion belonging to a compression chamber having a relatively larger compression gradient is smaller than that of the bypass portion belonging to the other compression chamber.

In a rotary piston and cylinder device (1) having a stator and a rotor, in which the stator at least partially defines an annular cylinder space and the rotor includes at least one piston that extends from the rotor into the cylinder space, and in which, during use, the piston moves through the annular cylinder space on rotation of the rotor relative to the stator, wherein at least part of an outer surface (30) of the rotor (22) is a substantially frusto-conical shaped surface.

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.

In an oil-cooled screw compressor, a tooth crest arc of a fixed width is provided to the tooth crest of a male tooth profile, and simultaneously a tooth bottom arc is provided to the tooth bottom of a female tooth profile. Due to the actions thereof, the operation chamber immediately before disappearing exists only in a bottom half region from a line that connects the centers of the male and female tooth profiles, and the opening area relative to the volume of the operation chamber can be increased. As a result, the discharge of oil becomes smooth and energy loss is reduced.

The present invention provides a co-rotating scroll compressor that can inhibit leakage of lubricant supplied to a synchronous drive mechanism. A co-rotating scroll compressor includes a drive-side plate 20 placed between a driving scroll member 70 and a motor 5 at a predetermined distance from the driving scroll member 70 in a direction of a drive-side rotation axis CL1. The drive-side plate 20 includes a shaft portion 20b fixed to a driving shaft 6 of the motor 5 and a fixing portion 20a fixed to an outer periphery of the driving scroll member 70, and a synchronous drive mechanism made up of a needle bearing 32a and a pin 32b is placed between the drive-side plate 20 and driving scroll member 70.

A compressor may include first and second scrolls and a seal. The first scroll includes a first end plate and a first spiral wrap extending from the first end plate. The first end plate may define a discharge passage and an annular recess surrounding the discharge passage. The second scroll includes a second end plate and a second spiral wrap extending from the second end plate. The first and second spiral wraps cooperate to define a plurality of fluid pockets. The seal may be at least partially received in the annular recess and may cooperate with the first scroll to define a biasing chamber receiving fluid at an intermediate pressure. The seal may include inner and outer diametrical surfaces. The inner diametrical surface may include a plurality of first annular grooves. The outer diametrical surface may include a plurality of second annular grooves.

A positive displacement rotary compressor is designed for near isothermal compression, high pressure ratios, high revolutions per minute, high efficiency, mixed gas/liquid compression, a low temperature increase, a low outlet temperature, and/or a high outlet pressure. Liquid injectors provide cooling liquid that cools the working fluid and improves the efficiency of the compressor. A gate moves within the compression chamber to either make contact with or be proximate to the rotor as it turns.

A positive displacement rotary compressor is designed for near isothermal compression, high pressure ratios, high revolutions per minute, high efficiency, mixed gas/liquid compression, a low temperature increase, a low outlet temperature, and/or a high outlet pressure. Liquid injectors provide cooling liquid that cools the working fluid and improves the efficiency of the compressor. A gate moves within the compression chamber to either make contact with or be proximate to the rotor as it turns.