Abstract: In a cross section of a flow passage formed to conduct a flow of air from an inside/outside air box to an upper air passage of a scroll casing while the cross section of the flow passage is taken along an imaginary plane which includes an outer edge of an air guide plate and is parallel to a rotational axis of an impeller, a passage section, which is located on one radial side of a separation tube where a nose of the scroll casing is placed, is defined as a first opening section, and another passage section, which is located on an opposite radial side of the separation tube, which is opposite to the nose, is defined as a second opening section. A passage cross-sectional area of the second opening section is larger than a passage cross-sectional area of the first opening section.

Abstract: An air conditioner includes an air conditioning case, a blower fan, and a facing wall portion. The air conditioning case configures an air passage through which air to be blown into an interior flows. The blower fan is disposed inside the air conditioning case. The facing wall portion is disposed on an air flow upstream side of the blower fan to face a suction port of the blower fan. The air conditioning case has a facing surface that faces the facing wall portion and in which through holes are formed. The air conditioning case has a closed space formed therein on an opposite side of the facing surface with respect to the air passage and communicating with the air passage via the through holes. The through holes and the closed space form a resonator having a predetermined resonance frequency.

Abstract: A centrifugal blower includes a centrifugal fan and a separation cylinder. The centrifugal fan has a separation plate. The separation cylinder is disposed inward of the blades in the radial direction of the centrifugal fan. The separation plate has an inner end surface extending from the one side to the other side in the axial direction at a position of an inner end in the radial direction. The separation cylinder has a separation cylinder end surface extending from the one side to the other side in the axial direction at a position of an end on the other side in the axial direction. A height of one of the separation cylinder end surface and the inner end surface in the axial direction is larger than a height of the other of the separation cylinder end surface and the inner end surface in the axial direction.

Abstract: A centrifugal blower includes a centrifugal fan and a separation cylinder. The centrifugal fan has a separation plate. The separation cylinder is disposed inward of the blades in the radial direction of the centrifugal fan. The separation plate has an inner end surface extending from the one side to the other side in the axial direction at a position of an inner end in the radial direction. The separation cylinder has a separation cylinder end surface extending from the one side to the other side in the axial direction at a position of an end on the other side in the axial direction. A height of one of the separation cylinder end surface and the inner end surface in the axial direction is larger than a height of the other of the separation cylinder end surface and the inner end surface in the axial direction.

Abstract: A centrifugal fan includes first blades and second blades connected via a separation plate. A side plate supports the first blades located on one side in an axial direction, and a main plate supports the second blades on the other side in the axial direction. The separation plate has an inner diameter larger than or equal to an outer diameter of the main plate and larger than or equal to a largest inner diameter of the second blade. The separation plate has an outer diameter smaller than or equal to an inner diameter of the side plate and smaller than or equal to a smallest outer diameter of the first blade.

Abstract: A centrifugal blower includes: a centrifugal fan having plural blades arranged around a fan axis and a separation plate to blow out air in a radial direction after being sucked from one side in an axial direction; a fan casing housing the centrifugal fan; a partition plate that defines a first air passage and a second air passage arranged on the other side of the first air passage in the axial direction; and a separation cylinder arranged inside the plural blades in the radial direction. The separation cylinder expands in the radial direction as extending toward the other side in the axial direction, and is shaped to extend outward in the radial direction obliquely to the axial direction at the other end position of the separation cylinder positioned at the other end in the axial direction.

Abstract: A blower device includes a passage-forming section that forms a passage through which air flows inside. A partition section is provided within the passage-forming section. The partition section divides at least a part of the passage into a first passage and a second passage. The partition section has a hole. The hole passes through the partition section and provides a constant communication between the first passage and the second passage.

Abstract: A centrifugal fan includes first blades and second blades connected via a separation plate. A side plate supports the first blades located on one side in an axial direction, and a main plate supports the second blades on the other side in the axial direction. The separation plate has an inner diameter larger than or equal to an outer diameter of the main plate and larger than or equal to a largest inner diameter of the second blade. The separation plate has an outer diameter smaller than or equal to an inner diameter of the side plate and smaller than or equal to a smallest outer diameter of the first blade.

Abstract: A centrifugal blower includes a box, a filter, an impeller, a scroll casing, a bell mouth, a partition wall, and a separation tube. The scroll casing defines an air passage gradually increasing from a nose portion in a circumferential direction. The partition wall divides the air passage into an upper passage and a lower passage. The separation tube includes an air introducing plate to partially cover the impeller and defining an air inlet portion and a tubular portion that extends from the air inlet portion through the impeller. On a virtual plane parallel to a rotational axis of the impeller, an outer edge of the air introducing plate extends and a passage between the filter and the upper passage is divided by the separation tube into a first passage cross-section closer to the nose portion and a second passage cross-section that is smaller than the first passage cross-section.

Abstract: In a cross section of a flow passage formed to conduct a flow of air from an inside/outside air box to an upper air passage of a scroll casing while the cross section of the flow passage is taken along an imaginary plane which includes an outer edge of an air guide plate and is parallel to a rotational axis of an impeller, a passage section, which is located on one radial side of a separation tube where a nose of the scroll casing is placed, is defined as a first opening section, and another passage section, which is located on an opposite radial side of the separation tube, which is opposite to the nose, is defined as a second opening section. A passage cross-sectional area of the second opening section is larger than a passage cross-sectional area of the first opening section.

Abstract: A centrifugal blower includes a centrifugal fan and a separation cylinder. The centrifugal fan has a separation plate. The separation cylinder is disposed inward of the blades in the radial direction of the centrifugal fan. The separation plate has an inner end surface extending from the one side to the other side in the axial direction at a position of an inner end in the radial direction. The separation cylinder has a separation cylinder end surface extending from the one side to the other side in the axial direction at a position of an end on the other side in the axial direction. A height of one of the separation cylinder end surface and the inner end surface in the axial direction is larger than a height of the other of the separation cylinder end surface and the inner end surface in the axial direction.

Abstract: A centrifugal blower includes: a centrifugal fan having plural blades arranged around a fan axis and a separation plate to blow out air in a radial direction after being sucked from one side in an axial direction; a fan casing housing the centrifugal fan; a partition plate that defines a first air passage and a second air passage arranged on the other side of the first air passage in the axial direction; and a separation cylinder arranged inside the plural blades in the radial direction. The separation cylinder expands in the radial direction as extending toward the other side in the axial direction, and is shaped to extend outward in the radial direction obliquely to the axial direction at the other end position of the separation cylinder positioned at the other end in the axial direction.

Abstract: A blower device includes a passage-forming section that forms a passage through which air flows inside. A partition section is provided within the passage-forming section. The partition section divides at least a part of the passage into a first passage and a second passage. The partition section has a hole. The hole passes through the partition section and provides a constant communication between the first passage and the second passage.

Abstract: An air conditioner includes an air conditioning case, a blower fan, and a facing wall portion. The air conditioning case configures an air passage through which air to be blown into an interior flows. The blower fan is disposed inside the air conditioning case. The facing wall portion is disposed on an air flow upstream side of the blower fan to face to a suction port of the blower fan. The air conditioning case has a facing surface that face to the facing wall portion and in which through holes are formed. The air conditioning case has a closed space formed therein on an opposite side of the air passage with respect to the facing surface and communicating with the air passage via the through holes. The through holes and the closed space form a resonator having a predetermined resonance frequency.

Abstract: A centrifugal blower includes a rotation shaft, an impeller, a casing. The impeller includes a plurality of blades and a side panel. The casing accommodates the impeller and includes an air intake portion positioned adjacent to the side panel. The air intake portion includes a downstream end portion and an inner wall surface. The side panel includes an upstream end portion and an inner panel surface that is an inner surface of the side panel. The downstream end portion and the upstream end portion face each other across a space in an angular range. A difference between a smallest inner radius of the inner wall surface of the air intake portion and a smallest inner radius of the inner panel surface is smaller than or equal to a thickness of the side panel in the angular range.

Abstract: A centrifugal blower includes a centrifugal fan and a partition cylinder portion. The centrifugal fan includes first blades and second blades arranged about a fan central axis. The partition cylinder portion has a cylindrical shape extending in an axial direction. A diameter of the partition cylinder portion expands in the axial direction. The partition cylinder portion is located inside the second blades in the radial direction. The partition cylinder portion partitions, on an airflow upstream side of the first blades and the second blades, air drawn into spaces between the first blades from air drawn into spaces between the second blades. A length of each first blade in the radial direction is larger than a length of each second blade in the radial direction.

Abstract: A centrifugal blower includes a rotation shaft, an impeller, a casing. The impeller includes a plurality of blades and a side panel. The casing accommodates the impeller and includes an air intake portion positioned adjacent to the side panel. The air intake portion includes a downstream end portion and an inner wall surface. The side panel includes an upstream end portion and an inner panel surface that is an inner surface of the side panel. The downstream end portion and the upstream end portion face each other across a space in an angular range. A difference between a smallest inner radius of the inner wall surface of the air intake portion and a smallest inner radius of the inner panel surface is smaller than or equal to a thickness of the side panel in the angular range.