A compressor which includes a male rotor assembly including an elongate male helical-shaped rotor having an axial cylindrical cavity therethrough, a stationary shaft axially aligned with the male rotor and through the cavity, a housing for housing the male rotor and its associated stationary shaft therein, wherein the shaft is fixed within the housing, and bearing means mounted within the cavity of the male rotor for bearing the friction between the rotor and the shaft as the male rotor rotates about the stationary shaft.

A scroll compressor is disclosed. The scroll compressor may include an anti-rotation mechanism provided with an anti-rotation pin and an anti-rotation ring between an orbiting scroll and a scroll support member facing the orbiting scroll, and an axial thickness of the ring body portion constituting the anti-rotation ring may be larger than an axial depth of a ring insertion groove in which the anti-rotation ring is inserted. This can allow the orbiting scroll and a member facing the same to be spaced physically apart without a separate member, to secure a gap for oil to flow, such that the oil can be smoothly supplied between the orbiting scroll and the member, thereby suppressing seizure or/and friction loss between the orbiting scroll and the member.

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.

A scroll compressor includes a casing, a main frame, a rotating shaft, an orbiting scroll, a fixed scroll configured to engage the orbiting scroll to form a compression chamber, and an Oldham ring slidably coupled to the orbiting scroll to prevent rotation of the orbiting scroll. The Oldham ring includes: a ring body provided between the main frame and the orbiting scroll to be supported in an axial direction of the rotating shaft, and a key portion extending in the axial direction from the ring body and slidably inserted into a key accommodating portion provided in the orbiting scroll, the main frame, or the fixed scroll. The ring body or the key portion includes an oil supply passage for guiding oil accumulated in a member on which the ring body is supported to between the key portion and the key accommodating portion.

A screw compressor includes a housing, a first rotor rotatable about a first axis relative to the housing, and a second rotor rotatable about a second axis relative to the housing. The second rotor is enmeshed with the first rotor. A motor is embedded within the first rotor such that the motor is coaxial with the first axis.

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.

A compressor provided with a compressor element with a driven shaft, a motor with a drive shaft to drive the compressor element, and a transmission between the drive shaft and the driven shaft. The transmission includes a housing and at least a driven gearwheel that is mounted on the driven shaft and a drive gearwheel that is mounted on a drive shaft. The housing includes two separated chambers, a first chamber that is connected to the driven shaft and a second chamber which is separate from the first chamber. The first chamber is connected via a channel with the second chamber, whereby around the drive gearwheel or driven gearwheel, the second chamber is formed. The form of the second chamber is such that when the gearwheel in question rotates, a gas flow is created around this gearwheel which causes a negative pressure in the channel by the venturi effect.

A compressor includes a casing, an electric motor housed in an internal space of the casing, a drive shaft rotated by the electric motor, and a compression mechanism driven by the drive shaft discharge compressed refrigerant to the internal space. The internal space includes a first and second spaces formed near axial ends of the electric motor. The electric motor includes a stator and a rotating member. The stator is fixed to the casing. The rotating member includes a rotor rotatably inserted into the stator. The electric motor has a refrigerant flow path through which the first and second spaces communicate with each other. The refrigerant flow path includes a first flow path into which the refrigerant in the first space or the second space flows, and a rotor flow path extending axially across the rotor and connected to an outflow end of the first flow path.

An Oldham coupling structure for a scroll compressor decreases Oldham coupling pressure loading without increasing compressor diameter or significantly increasing orbiting scroll or Oldham coupling inertia. The Oldham coupling key height and area are increased by recessing the key face into the ring portion of the Oldham coupling, increasing the key height and adding pads to the involute side of the orbiting scroll base plate to extend the key slot, potentially resulting in reduced compressor diameter and/or reduced orbiting scroll and Oldham coupling inertia.

A dry vacuum pump is provided, including two shafts, respectively supporting at least one pumping rotor being configured to synchronously rotate in reverse in order to convey a gas to be pumped from an intake of the dry vacuum pump to an outlet; and a synchronous motor configured to rotate one shaft of the two shafts, the synchronous motor including a rotor coupled to the shaft, a first stator with windings arranged around the rotor, and at least one second stator with windings arranged around the rotor, the windings of the stators being configured to be supplied individually or simultaneously in order to adapt a power of the synchronous motor to a pumping load. A method for controlling a synchronous motor of a vacuum pump is also provided.