A casing treatment for a compressor includes one or more cavities in a casing disposed radially outwardly of tips of the compressor rotor blades. A liner is moveable relative to the casing between a first position and a second position. The liner is shaped to add a volume to the tip clearance gap when moving from the second position toward the first position. The liner is displaceable between the first and second positions in coordination with at least the rotation of inlet guide vanes (IGVs) between IGV positions.

A fan frame body structure includes a first frame body. The first frame body has a first upper end, a first lower end, a first frame wall and a first main flow way. The first main flow way passes through the first frame body and is formed with a first main inlet and a first main outlet respectively at the first upper end and the first lower end. A first subsidiary flow way is disposed in the first frame wall. The first subsidiary flow way is in parallel the first main flow way. The first subsidiary outlet is positioned at the first upper end of the first frame body in flush with and in adjacency to the first main inlet.

An impeller is provided, including a metal housing, a shaft, and a plastic member. The metal housing has a shaft mounting hole. The inner surface of the shaft mounting hole includes three or more contact points, and the contact points are closer to the shaft than other portions of the inner surface of the shaft mounting hole. The shaft passes through the shaft mounting hole and is affixed by the contact points. The metal housing divides the shaft into an upper section, a middle section, and a lower section. The plastic member passes through the shaft mounting hole and is in contact with the middle section.

According to an embodiment, a fan unit holding mechanism includes an installation bracket with a slot, a projection portion on the bracket, and an elastic member at a bottom of the slot. The installation bracket receives a fan unit within the slot. The projection portion is inserted into an attachment hole of the fan unit when the installation bracket receives the fan unit. The elastic member comes into contact with the fan unit and presses against the fan unit.

A micro fan is provided. The micro fan includes a rotor and a stator. The stator includes a plurality of axial induced coil units and a circuit board. The axial induced coil units are respectively preformed as a plurality of stator magnetic pole units, and are coupled to the circuit board. At least one of the coil units includes a coil and insulation material. The insulation material is block-shaped and covers at least a portion of the coil, and the central axis of the coil is parallel to the shaft of the rotor.

A compressor comprising: a stator assembly comprising a plurality of stator elements; a rotor assembly comprising a shaft to which is mounted at least one bearing, a permanent magnet and an impeller; a support body; and an outer can comprising an air inlet. The support body comprises a hollow elongate central part to which is mounted the at least one bearing, and inside which the magnet is positioned, the elongate central part comprising a plurality of openings, and the air inlet of the outer can is axially aligned at least partially with the plurality of openings in the elongate central part.

A blower device includes a pair of fans, a housing, and a lid. The pair of fans generates an airflow on one side in the axial direction along the central axis and is coaxially arranged. The housing has a tubular shape extending along the central axis, accommodates the pair of fans, and has two end surfaces opened in the axial direction. The lids cover axial end surfaces of the housing and provide ventilation. The lid includes an annular portion in contact with the inner peripheral surface of the housing and including a through hole penetrating in the radial direction. The housing includes an engagement protrusion that protrudes radially inward from the inner peripheral surface and engages with the periphery of the through hole.

A diagonal fan includes an electric motor, a housing, and a diagonal impeller received inside the housing and drivable via the motor. The diagonal flow during operation is deflected in an axial flow direction. The diagonal impeller includes impeller blades distributed in the circumferential direction and a slinger ring encloses said blades. The diagonal fan includes an inlet nozzle on the suction side accommodating a main flow for the diagonal fan. The inlet nozzle extends overlapping at least in sections relative to the radial section of the slinger ring forming a nozzle gap therewith. A bypass channel on the housing forms a flow connection from a pressure-side surrounding region (U) of the diagonal fan to an inflow side of the nozzle gap. During operation of the diagonal fan, a swirl-free secondary flow (NS) is guided at the inflow side of the nozzle gap via the bypass channel.

A shroud unit has multiple stay members for supporting an electric motor, which rotates a fan unit having multiple blade members. Each of the blade members is inclined with respect to a radial direction of the fan unit in a predetermined circumferential direction. The stay members include a first stay member and multiple second stay members. Each of the second stay members is inclined with respect to the radial direction in a circumferential direction opposite to the predetermined circumferential direction. The first stay members is inclined with respect to the radial direction in the predetermined circumferential direction. The first stay member is located at a position overlapping with one of air-flow areas of a circular opening formed in the shroud unit, when viewed it in a direction along a rotational center axis of the electric motor. A flow amount of the air passing through the air-flow area of the circular opening having the first stay member is smaller than a flow amount of the air passing through another air-flow area of the circular opening having the second stay member.

A series fan frame body structure includes a first fan frame body, a second fan frame body and a serial connection frame body. The serial connection frame body has a first opening and a second opening. The first and second openings arranged in nonparallel to each other. The first and second fan frame bodies are respectively disposed at the first and second openings. The first and second fan frame bodies are inclined from each other. The first and second fan frame bodies are serially connected in a nonparallel form. Therefore, in the system, due to the resistance of the structure with such configuration, the audio frequency dipole structure is destructed so that the periodical noise and vibration characteristic are lowered.