This screw compressor is provided with a screw rotor, a casing accommodating the screw rotor, and a liquid feed mechanism for feeding a liquid into an operating chamber enclosed by the casing, wherein the pitch of the screw rotor changes in the axial direction from a suction end surface toward a discharge end surface.

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 supercharger includes a rotor housing defining a pair of cylindrical chambers. A driving shaft bearing is to support a driving rotor shaft for rotation in the rotor housing. A driven shaft bearing is to support a driven rotor shaft for rotation in the rotor housing. An oil sump housing is to enclose a timing gear end of the rotor housing. A shaft seal is disposed between the rotor housing and each respective rotor shaft. The oil sump housing, the rotor housing and driving and driven shaft seals define a closed container for oil to lubricate the driving shaft bearing, the driven shaft bearing, a driving timing gear and a driven timing gear. The oil pools in the closed container and a top surface of the oil is spaced below the timing gears when the driving rotor shaft is in a vertical orientation.

Disclosed are an oil supplying mechanism, and a horizontal compressor having same. Disclosed is an oil supply mechanism for a horizontal compressor, the horizontal compressor including a housing, a motor, a rotating shaft driven by the motor, and a bearing pedestal supporting the rotating shaft. The oil supply mechanism includes a separating member, the separating member being in the form of a ring having a central hole for allowing the bearing pedestal to pass therethrough, and the separating member being configured to separate the housing into an oil storage chamber and a motor chamber with the motor provided therein. The separating member is constructed to have an annular groove opening into the oil storage chamber. The oil supply mechanism and the horizontal compressor having the oil supply mechanism can reduce or minimize free space in the motor chamber and/or facilitate a quality inspection on the structure of a pump.

Disclosed are an oil supplying mechanism, and a horizontal compressor having same. Disclosed is an oil supply mechanism for a horizontal compressor, the horizontal compressor including a housing, a motor, a rotating shaft driven by the motor, and a bearing pedestal supporting the rotating shaft. The oil supply mechanism includes a separating member, the separating member being in the form of a ring having a central hole for allowing the bearing pedestal to pass therethrough, and the separating member being configured to separate the housing into an oil storage chamber and a motor chamber with the motor provided therein. The separating member is constructed to have an annular groove opening into the oil storage chamber. The oil supply mechanism and the horizontal compressor having the oil supply mechanism can reduce or minimize free space in the motor chamber and/or facilitate a quality inspection on the structure of a pump.

A liquid supply type screw compressor that can suppress a rise in temperature of a liquid while reducing work for stirring the liquid is provided. The liquid supply type screw compressor has a male rotor 11A and a female rotor 11B, male-rotor-side working chambers formed at grooves of the male rotor 11A, and female-rotor-side working chambers formed at grooves of the female rotor 11B. In addition, the liquid supply type screw compressor has: a liquid supply nozzle 28 that is arranged on one side in the rotor axial direction which is a low-pressure side of an intersection P at which a high-pressure-side cusp 23 intersects a ridge line L of a trailing lobe tip of the female rotor 11B that defines a female-rotor-side working chamber V5 immediately after a start of delivery, the liquid supply nozzle 28 supplying the liquid to the male-rotor-side working chamber; and a liquid supply nozzle 29 that is arranged on the other side in the rotor axial direction which is a high-pressure side of the intersection P, and supplies the liquid to the male-rotor-side working chamber, and the liquid supply amount of the liquid supply nozzle 29 is made greater than the liquid supply amount of the liquid supply nozzle 28.

A liquid supply type screw compressor that can suppress a rise in temperature of a liquid while reducing work for stirring the liquid is provided. The liquid supply type screw compressor has a male rotor 11A and a female rotor 11B, male-rotor-side working chambers formed at grooves of the male rotor 11A, and female-rotor-side working chambers formed at grooves of the female rotor 11B. In addition, the liquid supply type screw compressor has: a liquid supply nozzle 28 that is arranged on one side in the rotor axial direction which is a low-pressure side of an intersection P at which a high-pressure-side cusp 23 intersects a ridge line L of a trailing lobe tip of the female rotor 11B that defines a female-rotor-side working chamber V5 immediately after a start of delivery, the liquid supply nozzle 28 supplying the liquid to the male-rotor-side working chamber; and a liquid supply nozzle 29 that is arranged on the other side in the rotor axial direction which is a high-pressure side of the intersection P, and supplies the liquid to the male-rotor-side working chamber, and the liquid supply amount of the liquid supply nozzle 29 is made greater than the liquid supply amount of the liquid supply nozzle 28.

In a scroll compressor, at an end plate surface of a fixed scroll, an annular back pressure groove connected to a back pressure chamber is provided, and an arc-shaped first groove and an arc-shaped second groove are provided inside the back pressure groove in a radial direction. A distance between the second groove and the back pressure groove is shorter than a distance between the first groove and the back pressure groove. A revolving scroll is provided with a first hole and a second hole for guiding lubricant oil from an oil supply path to the end plate surface side of the fixed scroll. At least part of a movement locus of an opening of the first hole is included in the first groove. At least part of a movement locus of an opening of the second hole is included in the second groove. The first groove and the second groove at least partially overlap with each other in the radial direction.

A rotor assembly and a compressor are provided. The rotor assembly has a crankshaft, a rotor core, a balance weight and an oil baffle shield. The rotor core is provided with a vent hole. The vent hole extends through the rotor core along an axial direction of the rotor core. The balance weight is located at one end of the rotor core approximate to an oil sump of the compressor. The oil baffle shield is arranged to cover the balance weight and is provided with a central opening. The crankshaft extends through the central opening. An accommodating space is defined between the oil baffle shield and the rotor core. The accommodating space is communicated with the vent hole.