A blower includes a propeller fan, and an enclosure. The propeller fan is configured to rotate around a rotation axis. The propeller fan includes a plurality of blades at unequal pitches. The enclosure houses the propeller fan. The enclosure includes a bell mouth. The enclosure has a depth L. The bell mouth includes a cylindrical part parallel to the rotation axis.

[00001]$0.14\le \frac{H2}{H0}\le 0.22\#$

A length of the blades is H0 in a rotation axis direction, and a length of the cylindrical part is H2 in the rotation axis direction.

The gas turbine compressor for an aircraft gas turbine engine includes a compressor rotor having a plurality of compressor blades circumferentially distributed around a hub. Each of the compressor blades has an airfoil extending radially outward from the hub to a blade tip. A circumferential row of the compressor blades includes two or more different blade types, at least one modified blade of the two or more different blade types having means for generating different shock patterns between adjacent ones of the two or more different blade types when the gas turbine compressor operates in supersonic flow regimes. The means for generating different shock patterns on the modified blade aerodynamically mistune the two or more different blade types.

The present invention relates to a jet structure of a fan rotor, which comprises a fan wheel and at least one connecting channel. The fan wheel has a hub and plural blades disposed on the circumferential side of the hub. The hub has a top portion and a sidewall. Each of the blades has an upper surface and a lower surface which form a high-pressure zone and a low-pressure zone, respectively. The connecting channel is provided with at least one first inlet disposed in the high-pressure zone and at least one first outlet disposed in the low-pressure zone. The first inlet and the first outlet are a first end and a second end of the connecting channel, respectively. By means of the design of the present invention, the effect of noise reduction can be achieved.

A vacuum pump includes: a particle transferring portion that functions as a means for transferring a particle in an exhaust direction of the gas particle by increasing or reducing a height of an upstream end of at least a part of rotor blades among a plurality of rotor blades that constitute an uppermost exhaust stage to realize a stepped structure in which heights of the upstream ends differ as the uppermost exhaust stage as a whole, and in a rotating body constituted by the plurality of rotor blades, the particle transferring portion, and a cylindrical portion that supports the plurality of rotor blades, an imbalance created with respect to the rotating body as a whole by a presence of a rotor blade of which a height of the upstream end has become higher than other rotor blades due to the stepped structure has been corrected.

An axial fan rotates around a rotating shaft. The axial fan includes a hub, and a plurality of blades extending in a radial direction from the hub. Each blade includes a leading edge, a trailing edge including a depression, and a reinforcing protrusion located at least forwardmost and having a wall thickness thicker than a surrounding portion. As viewed along a rotating shaft direction, when a first virtual line and a second virtual line perpendicular to the radial direction are drawn, the reinforcing protrusion extends radially inside of the first virtual line and extends radially outside of the second virtual line, the first virtual line and the second virtual line respectively pass through a rearmost first endpoint in the rotation direction on a radially inside of a rear end that substantially overlaps the depression, and a rearmost second endpoint on a radially outside of the rear end.

A heat dissipation fan includes: a body including a fan air inlet surface, a central shaft driving surface located inside the fan air inlet surface, and a plurality of protrusion structures configured at spacings in a circumference direction of the central shaft driving surface; and fan blades including first fan blades connected between the central shaft driving surface and the fan air inlet surface, and second fan blades connected between the protrusion structure and the fan air inlet surface. A fan air inlet angle is formed between each fan blade and the central shaft driving surface, and the plurality of protrusion structures are configured to vary the fan air inlet angle to control a flow field of an airflow entering the fan air inlet angle.

A geared compressor includes a drive gear, a first intermediate gear, a second intermediate gear, a first impeller and a second impeller connected to a first driven gear, and a third impeller and a fourth impeller connected to a second driven gear. When viewed from an axial direction, a drive axis of the drive gear is disposed below a first intermediate axis of the first intermediate gear, a second intermediate axis of the second intermediate gear, a first driven axis of the first driven gear, and a second driven axis of the second driven gear in a vertical direction. The first impeller has a larger outer diameter than the second impeller, the third impeller, and the fourth impeller.

A compact respiratory therapy device suitable for use by a patient during sleep to provide respiratory pressure therapy such as at a pressure between 4-30 cmH2O includes a housing, an inlet, an outlet, a motor including a rotor, and an impeller configured to be rotated by the rotor to deliver a flow of air from the inlet toward the outlet. The impeller includes a set of impeller blades, each impeller blade comprising a leading edge and a trailing edge; and a first shroud and a second shroud, each shroud at least partly defining a flow passage through the impeller, the first shroud comprising a wall defining a periphery of an impeller inlet. The compact respiratory therapy device is configured to deliver the flow of air from the outlet for delivery to the patient at a pressure between 4-30 cmH2O at an overall sound power level of less than 50 dB(A) thereby reducing any disturbance to a quality of sleep for the patient. A diameter of the impeller is less than 50 mm. The first shroud and the second shroud are configured such that the flow passage is narrower in an axial direction at an outer portion of the impeller than at an inner portion of the impeller; and a diameter of the impeller inlet is at least 50% of the diameter of the impeller.

A fan blade for an airplane turbojet, the blade including an airfoil extending axially between a leading edge and a trailing edge and including a plurality of airfoil sections stacked radially between a root section and a tip section. All of the airfoil sections situated between the root section and an airfoil section situated at a radial height corresponding to 30% of a total radial height of the airfoil possess a skeleton curve having a point of inflection.

Provided is an electric blower configured to include a centrifugal impeller provided with an intermediate blade, which reduces pressure loss inside an air path on a large air volume side and achieves high efficiency. In the electric blower, a first rotor blade and a second rotor blade each include an inner circumferential edge facing a central portion of a hub and connecting an upper edge and a lower edge. The inner circumferential edge of the second rotor blade includes a first portion connected to the lower edge, a second portion connected to the upper edge, and a third portion. The third portion is located between the first portion and the second portion. Among the first portion, the second portion, and the third portion, the first portion is located closest to an outer circumferential portion of the hub in a direction along a surface portion.