An impeller includes: a main plate to be rotated; an annular side plate having a suction port for air; and blades in a circumferential direction. Each of the blades has: an inner peripheral end; an outer peripheral end; a sirocco blade portion that includes the outer peripheral end, and forms a forward-swept blade; and a turbo blade portion that includes the inner peripheral end and forms a swept-back blade. The blade has an end portion facing the suction port and a base portion connected to the main plate, and the end portion has a smaller thickness than that of the base portion in the sirocco blade portion. The end portion of the blade has a blade shape, and in the end portion having the blade shape, a first blade thickness of an inner circumferential side of the impeller is greater than a second blade thickness of the outer circumferential side.

A blower of an HVAC system includes an air inlet, an air outlet, a blower wheel with blades, a motor operable to cause the blower wheel to rotate, and a blower housing within which the blower wheel is positioned. The blower housing includes a top panel, a bottom panel, and a connecting panel. The top panel and the bottom panel are connected to the connecting panel. The top panel includes a curved edge extending from a bottom edge of the connecting panel to a top edge of the connecting panel. An expansion angle of the curved edge of the top panel changes as a function of position along the curved edge of the top panel. The bottom panel may have a shape corresponding to a mirror image to that of the top panel.

A blower of an HVAC system includes an air inlet, an air outlet, a blower wheel with blades, a motor operable to cause the blower wheel to rotate, and a blower housing within which the blower wheel is positioned. The blower housing includes a top panel, a bottom panel, and a connecting panel. The top panel and the bottom panel are connected to the connecting panel. The top panel includes a curved edge extending from a bottom edge of the connecting panel to a top edge of the connecting panel. An expansion angle of the curved edge of the top panel changes as a function of position along the curved edge of the top panel. The bottom panel may have a shape corresponding to a mirror image to that of the top panel.

A radial fan comprising: a plurality of blades rotatable about an axis of rotation and extending radially from the axis of rotation; characterised in that each of the blades has a transverse profile that is symmetrical about a radial line of symmetry extending through the blade, at least a portion of the profile of each blade being curved.

A radial fan comprising: a plurality of blades rotatable about an axis of rotation and extending radially from the axis of rotation; characterised in that each of the blades has a transverse profile that is symmetrical about a radial line of symmetry extending through the blade, at least a portion of the profile of each blade being curved.

An airflow-doubling vane structure includes an axle, an inner vane unit, and an outer vane unit. The inner vane unit includes a plurality of vanes provided around a center defined by the axle and can be rotated along with the axle. The vanes of the inner vane unit are centrifugal vanes. The outer vane unit includes a plurality of vanes provided around the center defined by the axle and around the inner vane unit and can be rotated along with the axle. The vanes of the outer vane unit are axial-flow vanes and extend a certain radial distance from the vanes of the inner vane unit.

An airflow-doubling vane structure includes an axle, an inner vane unit, and an outer vane unit. The inner vane unit includes a plurality of vanes provided around a center defined by the axle and can be rotated along with the axle. The vanes of the inner vane unit are centrifugal vanes. The outer vane unit includes a plurality of vanes provided around the center defined by the axle and around the inner vane unit and can be rotated along with the axle. The vanes of the outer vane unit are axial-flow vanes and extend a certain radial distance from the vanes of the inner vane unit.

The present invention relates to an impeller comprising: a shroud having a plurality of spiral upper slot units formed therein; a hub located to face the shroud; and a plurality of blades connected to the hub and inserted into the upper slot units to be coupled to the shroud, wherein the blade includes a body portion formed to be inclined to one side and an upper end portion, which is bent upward from the body portion and has a second concave surface formed in one side and a second convex surface formed on the other side thereof, and the upper slot unit includes an upper slot bottom for forming a space in which the upper end portion is inserted; an upper slot wall divided into a first upper slot wall located at the second concave surface side and a second upper slot wall located at the second convex surface side; and a second inclined surface formed to be inclined from the first upper slot wall so as to face the second concave surface. Thus, the impeller secures the assembling of the blades and has the effect of reducing the possibility of separation of the blades during the high-speed rotation of the impeller, which improves the structural rigidity of the impeller.

The present invention relates to an impeller comprising: a shroud having a plurality of spiral upper slot units formed therein; a hub located to face the shroud; and a plurality of blades connected to the hub and inserted into the upper slot units to be coupled to the shroud, wherein the blade includes a body portion formed to be inclined to one side and an upper end portion, which is bent upward from the body portion and has a second concave surface formed in one side and a second convex surface formed on the other side thereof, and the upper slot unit includes an upper slot bottom for forming a space in which the upper end portion is inserted; an upper slot wall divided into a first upper slot wall located at the second concave surface side and a second upper slot wall located at the second convex surface side; and a second inclined surface formed to be inclined from the first upper slot wall so as to face the second concave surface. Thus, the impeller secures the assembling of the blades and has the effect of reducing the possibility of separation of the blades during the high-speed rotation of the impeller, which improves the structural rigidity of the impeller.

An impeller includes: a disk-shaped hub centered on an axis; and a plurality of blades arranged in a circumferential direction and protruding from a surface of the hub facing one side in a direction of the axis. In a cross-sectional view including a blade height direction which is a direction away from the hub toward a tip of each blade, the blade has a recessed surface curved convexly toward a rear side in a rotational direction. In the cross-sectional view, when a distance between an imaginary line connecting a tip-side edge and a hub-side edge of the blade and a midspan of the blade along a direction perpendicular to the imaginary line is defined as a recess amount, the blade has a portion where the recess amount increases from a leading edge side to a trailing edge side.