A lightweight impeller is provided for use in a pressurised gas source for a CPAP or other breathing assistance apparatus. The impeller can be shroudless or otherwise lightweight.

A lightweight impeller is provided for use in a pressurised gas source for a CPAP or other breathing assistance apparatus. The impeller can be shroudless or otherwise lightweight.

An air conditioner of the present disclosure includes a base case configured to include a suction port through which air is sucked and accommodate a filter therein, a tower case configured to be disposed above the base case and to include a discharge port through which the air sucked from the suction port is discharged, and a heater configured to be disposed inside the tower case to heat the air.

A centrifugal fan includes a housing and an impeller. The housing includes a sidewall, and the sidewall includes a tongue portion. The impeller includes a fan hub and a plurality of blades. The fan hub is rotatably disposed in the housing, and the tongue portion has an inner contour line on a reference plane. The blades connect to the fan hub. Each one of the blades has an end surface facing the sidewall. The end surface has an outer contour line on the section of the blade. Any two adjacent blades have different outer contour lines. The outer contour line of at least one first blade of the plurality of blades is parallel to the inner contour line. The outer contour line of at least one second blade of the plurality of blades is not parallel to the inner contour line.

A centrifugal fan includes a housing and an impeller. The housing includes a sidewall, and the sidewall includes a tongue portion. The impeller includes a fan hub and a plurality of blades. The fan hub is rotatably disposed in the housing, and the tongue portion has an inner contour line on a reference plane. The blades connect to the fan hub. Each one of the blades has an end surface facing the sidewall. The end surface has an outer contour line on the section of the blade. Any two adjacent blades have different outer contour lines. The outer contour line of at least one first blade of the plurality of blades is parallel to the inner contour line. The outer contour line of at least one second blade of the plurality of blades is not parallel to the inner contour line.

An impeller includes: a disk which is supported so as to be rotatable around an axis and which includes an outer peripheral surface expanding toward an outside in a radial direction of the disk as it goes to a downstream side in an axial direction of the axis; blades which are arranged on the outer peripheral surface of the disk at intervals in a circumferential direction of the disk; and a cover which is disposed at a position facing the outer peripheral surface of the disk so as to cover the blades. A leading edge of each of the blades includes: a straight portion which extends toward the downstream side in the axial direction of the axis as it goes to the disk from the cover; and a protrusion portion close to the disk and which is protruded from an extension of the straight portion.

An impeller includes: a disk which is supported so as to be rotatable around an axis and which includes an outer peripheral surface expanding toward an outside in a radial direction of the disk as it goes to a downstream side in an axial direction of the axis; blades which are arranged on the outer peripheral surface of the disk at intervals in a circumferential direction of the disk; and a cover which is disposed at a position facing the outer peripheral surface of the disk so as to cover the blades. A leading edge of each of the blades includes: a straight portion which extends toward the downstream side in the axial direction of the axis as it goes to the disk from the cover; and a protrusion portion close to the disk and which is protruded from an extension of the straight portion.

A fan including a hub and a plurality metal blades is provided. Each of the blades extends from the hub and is inclined relative to a radial direction of the hub. Each blade has a distal edge away from the hub, and has a pair of wingtips at the distal edge.

A fan including a hub and a plurality metal blades is provided. Each of the blades extends from the hub and is inclined relative to a radial direction of the hub. Each blade has a distal edge away from the hub, and has a pair of wingtips at the distal edge.

A process for optimizing the design of a semi-open centrifugal pump impeller involves the steps of, reducing the number of long blades and adding a medium length splitter blade and a short length splitter blade having varying circumferential distances between any two optimized long blades. Each medium length and short length splitter blade have the same outlet position, profile and thickness as the optimized long blade; however, the medium length and short length splitter blades have different inlet positions relative to the optimized long blade. The long blade, medium length splitter blade and short length splitter blade are arranged in circumferential sequence along the direction of rotation of the impeller. This optimization improves various problems arising from the original semi-open centrifugal pumps, including low efficiency, significant loss at the inlet, inlet cavitation, separation of boundary layers at the blade inlets, narrow lift range of the dead point and excessive noise.