A centrifugal compressor includes: an impeller which is allowed to rotate around an axis; a casing which is provided with a return flow path allowing a fluid pressure-fed from the impeller to flow therein; and a return vane which is disposed inside the return flow path, wherein the return vane is provided with an injection port through which a liquid supplied from the outside is injected to the return flow path. Accordingly, power is further reduced while suppressing pressure loss.

A return geometry fluidically connects a first and a second compressor stage of the turbocompressor. The return geometry has multiple partial helices that are evenly or unevenly distributed in the circumferential direction. The multiple partial helices extend at least in part in the circumferential direction. They form flow channels that extend at least in some sections, separately from each other, to fluidically connect the first and second compressor stages.

In an air conditioning case, a blower sucks air flowing out from first and second upstream side ventilation paths from one side in an axial direction of a fan axis by rotation of a blower fan and allows the sucked air to flow to first and second downstream side ventilation paths. An upstream side guide member is provided on one side in the axial direction with respect to the blower fan and guides the air to the blower fan. Further, the upstream side guide member has a twisted shape and guides the air to the blower fan along the twisted shape.

A heat pump includes a housing; a liquefier and an evaporator arranged inside the housing; and a compressor interposed between the evaporator and the liquefier in terms of fluid flow, the compressor having a motor, an impeller connected to the motor, and a diffusor, the diffusor having a diffusor portion extending between the motor and the impeller, the diffusor portion having at least two parts, a first part of the diffusor portion being connected to the housing and a second part of the diffusor portion being connected to the motor, wherein the first part of the diffusor portion has an opening, wherein the second part of the diffusor portion is configured to close the opening, and wherein the opening is dimensioned such that the impeller is removable from the housing through the opening.

There is provided a rotating machinery including: a rotating body R which is rotatable around an axis O and has a first facing surface P1 that widens in a plane intersecting the axis O; a stationary body S which faces the first facing surface P1 from the axial direction O, and has a second facing surface P2 forming a flow path F1 through which a fluid flows from a radially inner side toward the radially outer side between the first facing surface P1 and the second facing surface P2; and a rotation side projection portion 80 which projects from the first facing surface P1 toward the second facing surface P2, has an annular shape around the axis O, and faces the second facing surface P2 via a clearance C.

A motor includes a housing, an impeller and a diffuser in the housing, a rotor assembly and a stator assembly, the motor has an air inlet on the housing and an air outlet, the impeller is disposed adjacent to the air inlet and is connected to the rotor assembly, the diffuser is located downstream of the impeller, the stator assembly is located downstream of the diffuser, the housing includes a front housing and a rear housing connected to each other, a first air duct is enclosed among a rear inner wall of the front housing, a front inner wall of the rear housing and the diffuser and in communication with an outlet of the impeller and the air outlet, and an inner diameter size of the rear end of the rear inner wall is less than or equal to that of the front end of the front inner wall.

An air duct component includes first and second volute members arranged oppositely in a cross section perpendicular to an axis of a cross-flow impeller. An inner end of the first volute member includes a volute tongue. A cross-flow air duct formed between the first and second volute members includes a middle air duct section and an end air duct section arranged along an axial direction of the cross-flow impeller. The middle air duct section includes a middle air outlet duct located downstream of a vertical line that passes through the volute tongue and is perpendicular to the second volute member. The end air duct section includes an end air outlet duct located downstream of the vertical line. A cross-sectional area of the middle air outlet duct is larger than a cross-sectional area of the end air outlet duct.

A centrifugal fan includes: a fan, blades; and a scroll casing housing the fan, the scroll casing including a discharge portion, and a scroll portion including a side wall, a circumferential wall, and a tongue portion. In the circumferential wall, at a first end between the circumferential wall and the tongue portion, and at a second end between the circumferential wall and the discharge portion, a distance between an axis of the rotational shaft and the circumferential wall is equal to a distance between the axis of the rotational shaft and a standard circumferential wall, and is greater than or equal to the distance between the first end and the second end of the circumferential wall, the circumferential wall including a plurality of extended portions between the first end and the second end of the circumferential wall.

A mixed-flow compressor includes an impeller attached to a shaft and rotatable about a shaft axis. A vaneless diffuser is located axially downstream of the impeller and has a converging portion and a diverging portion. A vaned diffuser is located axially downstream of the vaneless diffuser.

A centrifugal compressor and a refrigerating device. The compressor includes: a shell, which has a fluid inlet at a first position of the shell, and a fluid outlet at a second position of the shell, a motor assembly, which is arranged in the shell and includes a stator and a rotor, the rotor including a vertically arranged rotor shaft, and the rotor shaft including a lower end and an upper end; a centrifugal compression mechanism, an impeller of which is connected with the rotor shaft so as to be driven by the motor assembly; and a guide member, which is located above the centrifugal compression mechanism, and which defines a flow passage alone or together with a top part of the shell.