An inclination angle between a direction perpendicular to a rotational axis and a tangential direction of a radially outer edge of a radially outermost concave arc portion, which is located outermost in the radial direction of an impeller among at least one concave arc portion, has a distribution along the circumferential direction of a scroll passage, and when a circumferential position in the scroll passage from a tongue of a scroll part to an outlet of the scroll passage is represented by a central angle about the rotational axis by using the tongue as a reference, the distribution of the inclination angle has a local minimum value or a minimum value in a range of the central angle of 30° to 210°.

The present invention relates to a reinforcing structure for a casing accommodating an impeller. A double-suction centrifugal pump includes: a rotational shaft (1); an impeller (2) secured to the rotational shaft (1); a casing (3) that accommodates the impeller (2) therein; and legs (5) secured to the casing (3). The casing (3) includes a suction volute (20) that communicates with a suction port (6), the casing (3) includes an upper casing (3a) and a lower casing (3b) fastened to each other, at least one rib (28A, 28B, 28C) is provided on each of both side surfaces of the lower casing (3b) constituting the suction volute (20), the rib (28A, 28B, 28C) extends in a radial direction of the rotational shaft (1) when viewed from an axial direction of the rotational shaft (1), and the rib (28A, 28B, 28C) is separated from the legs (5).

The present invention discloses volute for a centrifugal fan, which comprises a volute tongue having an inner wall; wherein, the volute tongue has an enclosed noise-reducing chamber, the volute tongue has a plurality of holes for allowing the air flow to enter into the noise-reducing chamber; and a sound collector and a speaker are disposed in the noise-reducing chamber. In the present invention, during the use of the centrifugal fan, a gas flow can enter the cavity through the holes on the inner wall. The sound collector can acquire a noise signal and transmit it to a controller, and the controller calculates a noise-reduced audio signal according to the acquired signal and then controls the speaker to play the corresponding reduced noise according to the noise-reduced audio signal, so that the active noise reduction is realized. With such a structure, the vortex at the volute tongue is eliminated, thus the fan noise is reduced and the fan efficiency is improved.

A blower includes a housing including an inlet and an outlet, a stationary component provided to the housing, an impeller positioned between the inlet of the housing and the stationary component, a shield portion including an outer edge substantially aligning with or extending beyond an outer edge of the impeller, and a motor adapted to drive the impeller. The housing and the stationary component cooperate to define a volute that directs air towards the outlet, and the housing includes a separating wall constructed and arranged to divide the volute into a high speed airpath region and a low speed airpath region. The outer edge of the shield portion and the separating wall define a gap between the high speed airpath region and the low speed airpath region.

A radial compressor of an exhaust gas turbocharger, with a rotating impeller, a fixed housing; a main flow passage defined by the housing for feeding a medium to be compressed towards the impeller; a secondary flow chamber arranged radially outside the main flow passage, which is separated from the main flow passage by a contour wall and is connected to the main flow passage via a secondary flow opening; struts extending in the secondary flow chamber, via which the contour wall is connected to the housing. The struts are curved having a first connecting section of the contour wall that extends in the radial direction and a second connecting section on the housing that extends in the axial direction.

A compressor includes a compressor impeller configured to rotate about an axis of rotation as intake gases flow along the compressor impeller. The compressor impeller includes an inducer and an exducer. The compressor impeller defines a first impeller end at the inducer and a second impeller end at the exducer. The second impeller end extends along a radial axis. The compressor further includes a compressor housing encasing the compressor impeller. The compressor housing defines a compressor volute. The compressor housing partially defines a diffuser in fluid communication with the compressor volute. The diffuser is elongated along a diffuser axis. The diffuser axis is obliquely angled relative to the axis of rotation. The diffuser axis is obliquely angled relative to the radial axis to minimize a turbulence of the intake gases flowing from the diffuser to the compressor volute.

A fan unit that forms part of a gases supply unit used as part of a breathing assistance system for providing heated gases to a user is provided. The fan unit has an impeller surrounded by an upwardly sloped surface to facilitate improved airflow performance under surge conditions. The impeller includes a plurality of blades capped by a lid having a central aperture to provide an inlet to the impeller.

A volute casing includes a chamber, an outlet passage, and a cutwater to direct fluid to the outlet passage. The cutwater includes an inner surface, an outer surface and a leading edge joining the inner and outer surfaces and has a cross-sectional contour in a midplane perpendicular to the axial direction. The cross-sectional contour includes a starting point at the leading edge, and a minimum point on the inner surface, the starting point defined by a tangent to the leading edge, the tangent intersecting the central axis, and the minimum point defined by a location, at which the inner surface has a minimum distance from the central axis. A straight profile chord located in the cross-sectional contour, and extending from the cutwater starting point to the cutwater minimum point, has a maximum orthogonal distance from the inner surface being at most 15% of the length of the profile chord.

A centrifugal blower has a first housing section and a second housing section separated by a width of the centrifugal blower. The centrifugal blower also has an intake port extending through the first housing section and the second housing section along the width, and an outlet port formed by the first housing section and the second housing section. A dimension of the width continuously decreases as the outlet port is approached along a length of the centrifugal blower.

A housing for an air cycle machine includes a first housing portion adjacent a first end of the housing, and a second housing portion adjacent a second end of the housing and attached to the first housing portion. A first duct in the first housing portion is adjacent the first end of the housing with an air inlet and an air outlet. A second duct in the second housing portion is adjacent the second end of the housing with an air inlet and an air outlet. The housing further includes a bolt hole positioned in the second end of the housing, and a rib extending between the first housing portion and the second housing portion. The rib is aligned with the bolt hole.