Abstract: A centrifugal blower includes a case, an electric motor supported by the case at a motor support position, and a fan driven by the electric motor. The fan includes: a boss installed to an output shaft; a main plate extending outward from the boss in a radial direction; a plurality of blades extending from the main plate toward one side in an axial direction; and a side plate joined to an end portion of each of the plurality of blades, which faces the one side in the axial direction. A weight of the main plate is larger than a weight of the side plate. The main plate and the side plate are both inclined toward another side opposite to the one side in the axial direction as the main plate and the side plate approach an outer side in the radial direction.

Abstract: A fan includes blades and a side plate. The side plate includes a fan ring portion having a cylindrical shape centered on a fan axis. A guide part that is annular is arranged on one side of the fan ring portion in the axial direction and forms a suction port through which the air sucked into the fan passes. A communication path that allows an upstream space located on the one side in the axial direction with respect to the guide part to communicate with a gap between the fan ring portion and the guide part is formed outside the guide part in a radial direction of the fan axis. The fan ring portion is located outside in the radial direction with respect to an innermost peripheral portion of the guide part located on an innermost side in the radial direction.

Abstract: Each of a plurality of blades of a turbofan includes a thick wall portion, a thin wall portion and a stepped portion. The stepped portion is formed between the thick wall portion and the thin wall portion. A plate thickness of the stepped portion is progressively decreased toward a positive pressure surface of the blade in a direction that is directed from the thick wall portion toward the thin wall portion. In the blade, a first curved surface forms a negative pressure surface of the thick wall portion, and a second curved surface forms a negative pressure surface of the thin wall portion while the second curved surface is located on a side of the first curved surface where the positive pressure surface of the blade is placed, and a negative pressure surface of the stepped portion connects between the first curved surface and the second curved surface.

Abstract: A blower includes a drive device, a shaft, a fan and a rotation limiter member. The fan includes: a main plate that has an axial hole which is securely press-fitted to the shaft; a shroud that is opposed to the main plate and has a suction inlet, which is formed at a center part of the shroud; and a plurality of blades that are placed between the shroud and the main plate and are arranged one after another around a central axis of the fan. The rotation limiter member is fixed to the shaft and the main plate. The main plate includes: a slope portion that is placed on an outer side of the rotation limiter member; and at least one planar surface part which is perpendicular to the central axis and is formed around the central axis at a part of the slope portion.

Abstract: Each of a plurality of blades of a turbofan includes a thick wall portion, a thin wall portion and a stepped portion. The stepped portion is formed between the thick wall portion and the thin wall portion. A plate thickness of the stepped portion is progressively decreased toward a positive pressure surface of the blade in a direction that is directed from the thick wall portion toward the thin wall portion. In the blade, a first curved surface forms a negative pressure surface of the thick wall portion, and a second curved surface forms a negative pressure surface of the thin wall portion while the second curved surface is located on a side of the first curved surface where the positive pressure surface of the blade is placed, and a negative pressure surface of the stepped portion connects between the first curved surface and the second curved surface.

Abstract: A centrifugal blower includes an outer rotor, and a turbo fan. The turbo fan includes blades, an other end plate, and a cylinder portion. The cylinder portion is located inside the other end plate, and is fixed to the outer rotor. A surface of the outer rotor configures a rotor guide surface that guides an air flow toward a channel provided between adjacent blades. Each blade has a leading edge side portion located radially inside the cylinder portion. An outer end portion of the rotor guide surface in the radial direction is located at the same position in the axial direction as a one side cylinder end portion of the cylinder portion in the axial direction, in a state where a rotor contact portion of the outer rotor and a blade contact portion of the leading edge side portion are in contact with each other.

Abstract: A method for manufacturing a turbo fan unit includes a step for preparing multiple fan blades and an other-side side plate, and a step for connecting each of the multiple fan blades to the other-side side plate by a welding process. In the preparing step, one of the fan blade and the side plate is prepared, in which a connecting-surface forming portion having a connecting surface and a welding projection protruded from the connecting surface is formed. The connecting surface connects one of the fan blade and the side plate to the other one of the fan blade and the side plate. In the connecting step, the welding projection is melted down and the connecting surface is connected to an opposing surface, which is the surface of one of the fan blade and the side plate and which is opposing to the connecting surface.

Abstract: A fan includes blades and a side plate. The side plate includes a fan ring portion having a cylindrical shape centered on a fan axis. A guide part that is annular is arranged on one side of the fan ring portion in the axial direction and forms a suction port through which the air sucked into the fan passes. A communication path that allows an upstream space located on the one side in the axial direction with respect to the guide part to communicate with a gap between the fan ring portion and the guide part is formed outside the guide part in a radial direction of the fan axis. The fan ring portion is located outside in the radial direction with respect to an innermost peripheral portion of the guide part located on an innermost side in the radial direction.

Abstract: A centrifugal blower device includes a rotating shaft, a turbo fan unit and a casing. A shroud ring of the turbo fan unit and a cover portion of the casing form a gap between them. The gap includes a radial gap formed between the cover portion and the shroud ring in a radial direction and an axial gap formed between the cover portion and the shroud ring in an axial direction. The radial gap is located at a position outside of a shroud-side inner peripheral end in the radial direction. The axial gap is located at a position inside of the radial direction in the radial direction. A minimum gap dimension of the radial gap is smaller than a minimum gap dimension of the axial gap. A shortest distance between the shroud-side inner peripheral end and the cover portion is larger than the minimum gap dimension of the radial gap.

Abstract: A fan main body member of a turbofan has multiple blades disposed around a fan axial center, a shroud ring which is coupled to each of the multiple blades, and a fan hub portion which is coupled to each of the multiple blades on a side opposite from the shroud ring. An other end side plate of the turbofan is fitted to the radially outer side of the fan hub portion and joined to an other side blade end portions of each of the multiple blades. In addition, an outer diameter of the fan hub portion is smaller than an inner diameter of the shroud ring. In addition, the multiple blades, the shroud ring, and the fan hub portion are integrally formed.

Abstract: A centrifugal blower includes a turbofan. The turbofan includes blades, a shroud ring, and a main panel. Each blade includes a leading edge that is located inward of the shroud ring in a radial direction of the turbofan, and a trailing edge that is located on an outer side in the radial direction of the turbofan. The leading edge includes a second side region located on the second side in the rotation axis direction, and a first side region located on the first side of the second side region in the rotation axis direction. The first side region is located on the first side in the rotation axis direction compared with the trailing edge. Stepped portions are formed only in a part of the leading edge, the stepped portions being formed in the first side region or in the first side region and the second side region.

Abstract: A centrifugal blower includes: a centrifugal fan, which includes a shroud ring; and a case. The case includes a cover portion that covers a surface of the shroud ring located on one side in an axial direction. The cover portion includes a recess formed in a cover opposing surface, which is opposed to the shroud ring, and the recess is shaped in a form of a circle. The shroud ring includes at least one projection that is formed in a ring opposing surface, which is opposed to the cover portion. A gap is formed between the cover portion and the shroud ring. A shortest distance between a radially inner end part of the shroud ring and the cover portion is set to be larger than a shortest distance between a surface of the projection and a surface of the recess.

Abstract: A centrifugal blower includes a centrifugal fan and a case that houses the centrifugal fan. A blade of the centrifugal fan has an intake side edge portion extending from a shroud inward in a radial direction. The intake side edge portion has a negative pressure side inclined portion inclined to a negative pressure surface side of the blade with respect to an axial direction. The negative pressure side inclined portion has an inclination length in the axial direction, and the inclination length is larger in a reverse flow portion of the intake side edge portion close to the shroud than in a radially innermost portion of the intake side edge portion located at an innermost side in the radial direction.

Abstract: A centrifugal blower includes an outer rotor, and a turbo fan. The turbo fan includes blades, an other end plate, and a cylinder portion. The cylinder portion is located inside the other end plate, and is fixed to the outer rotor. A surface of the outer rotor configures a rotor guide surface that guides an air flow toward a channel provided between adjacent blades. Each blade has a leading edge side portion located radially inside the cylinder portion. An outer end portion of the rotor guide surface in the radial direction is located at the same position in the axial direction as a one side cylinder end portion of the cylinder portion in the axial direction, in a state where a rotor contact portion of the outer rotor and a blade contact portion of the leading edge side portion are in contact with each other.

Abstract: A centrifugal blower includes an outer rotor, and a turbo fan. The turbo fan includes blades, an other end plate, and a cylinder portion. The cylinder portion is located inside the other end plate, and is fixed to the outer rotor. A surface of the outer rotor configures a rotor guide surface that guides an air flow toward a channel provided between adjacent blades. Each blade has a leading edge side portion located radially inside the cylinder portion. An outer end portion of the rotor guide surface in the radial direction is located at the same position in the axial direction as a one side cylinder end portion of the cylinder portion in the axial direction, in a state where a rotor contact portion of the outer rotor and a blade contact portion of the leading edge side portion are in contact with each other.

Abstract: A fan main body member of a turbofan has multiple blades disposed around a fan axial center, a shroud ring coupled to each of the blades, and a fan hub portion coupled to each of the blades on a side opposite from the shroud ring. An other end side plate of the turbofan is joined to each of the other side blade end portions of the blade in a state of being fitted to the radially outer side of the fan hub portion. A fitting gap between the other end side plate and the fan hub portion is formed such that an outflow velocity of air when air passes through the fitting gap and outflows is reduced as compared to when air passes through a virtual reference gap that corresponds to the fitting gap and outflows.

Abstract: A method for manufacturing a turbo fan unit includes a step for preparing multiple fan blades and an other-side side plate, and a step for connecting each of the multiple fan blades to the other-side side plate by a welding process. In the preparing step, one of the fan blade and the side plate is prepared, in which a connecting-surface forming portion having a connecting surface and a welding projection protruded from the connecting surface is formed. The connecting surface connects one of the fan blade and the side plate to the other one of the fan blade and the side plate. In the connecting step, the welding projection is melted down and the connecting surface is connected to an opposing surface, which is the surface of one of the fan blade and the side plate and which is opposing to the connecting surface.

Abstract: A centrifugal blower device includes a rotating shaft, a turbo fan unit and a casing. A shroud ring of the turbo fan unit and a cover portion of the casing form a gap between them. The gap includes a radial gap formed between the cover portion and the shroud ring in a radial direction and an axial gap formed between the cover portion and the shroud ring in an axial direction. The radial gap is located at a position outside of a shroud-side inner peripheral end in the radial direction. The axial gap is located at a position inside of the radial direction in the radial direction. A minimum gap dimension of the radial gap is smaller than a minimum gap dimension of the axial gap. A shortest distance between the shroud-side inner peripheral end and the cover portion is larger than the minimum gap dimension of the radial gap.

Abstract: A centrifugal blower device has a turbo fan unit and a casing. The casing includes a first casing member and a second casing member. One of the first casing member and the second casing member includes a first step portion having a first surface, a second step portion having a second surface, and a third step portion having a third surface. Each of the first surface, the second surface and the third surface forms a part of an outer surface of the one of the casing members and has a position different from one another in an axial direction. The second surface is located at a position closer than the first surface to the other one of the first casing member and the second casing member. The third surface is located at a position closer than the second surface to the other one of the casing members.

Abstract: A centrifugal blower includes a turbofan. The turbofan includes blades, a shroud ring, and a main panel. Each blade includes a leading edge that is located inward of the shroud ring in a radial direction of the turbofan, and a trailing edge that is located on an outer side in the radial direction of the turbofan. The leading edge includes a second side region located on the second side in the rotation axis direction, and a first side region located on the first side of the second side region in the rotation axis direction. The first side region is located on the first side in the rotation axis direction compared with the trailing edge. Stepped portions are formed only in a part of the leading edge, the stepped portions being formed in the first side region or in the first side region and the second side region.