Impeller, multi-blade fan, and air-conditioning apparatus

A multi-blade fan comprising:

• an impeller including a main plate configured to be driven to rotate, an annular side plate provided opposite to the main plate, and a plurality of blades connected to the main plate and the side plate and arranged in a circumferential direction with respect to a rotation axis of the main plate;
• and
• a scroll casing housing the impeller, and having a peripheral wall formed into a volute shape and a side wall including a bellmouth that forms an air inlet communicating with a space defined by the main plate and the plurality of blades,
• wherein each of the plurality of blades has
• an inner circumferential end located closer to the rotation axis in a radial direction from the rotation axis,
• an outer circumferential end located closer to an outer circumferential side than the inner circumferential end in the radial direction,
• a sirocco blade portion formed as a forward-swept blade portion, including the outer circumferential end, and having an outlet angle that is greater than 90 degrees, and
• a turbo blade portion formed as a swept-back blade portion and including the inner circumferential end, and
• wherein the plurality of blades include
• a first blade portion provided on one plate side of the main plate, and
• a second blade portion provided on an other plate side of the main plate,
• wherein the impeller includes a region in which a first inter-blade distance is greater than a second inter-blade distance, where an inter-blade distance is a distance between any adjacent two of the plurality of blades in the circumferential direction, the first inter-blade distance is the inter-blade distance of the first blade portion, and the second inter-blade distance is the inter-blade distance of the second blade portion, and
• wherein the plurality of blades are formed such that a blade outside diameter of the plurality of blades that is a diameter of a circle drawn through the outer circumferential ends of the plurality of blades is larger than an inside diameter of the bellmouth, and
• in portions of the plurality of blades that are located closer to the outer circumferential side, in the radial direction, than an inner circumferential side of the bellmouth that has the inside diameter of the bellmouth, a ratio of the turbo blade portion in the radial direction is higher than a ratio of the sirocco blade portion in the radial direction throughout the plurality of blades.

An impeller comprising:

• a main plate configured to be driven to rotate;
• an annular side plate provided opposite to the main plate;
• and
• a plurality of blades connected to the main plate and the side plate and arranged in a circumferential direction with respect to a rotation axis of the main plate,
• wherein each of the plurality of blades has
• an inner circumferential end located closer to the rotation axis in a radial direction from the rotation axis,
• an outer circumferential end located closer to an outer circumferential side than the inner circumferential end in the radial direction,
• a sirocco blade portion formed as a forward-swept blade portion, including the outer circumferential end, and having an outlet angle that is greater than 90 degrees, and
• a turbo blade portion formed as a swept-back blade portion and including the inner circumferential end,
• wherein the plurality of blades include
• a first blade portion provided on one plate side of the main plate, and
• a second blade portion provided on an other plate side of the main plate,
• the impeller including a region in which a first inter-blade distance is greater than a second inter-blade distance, where an inter-blade distance is a distance between any adjacent two of the plurality of blades in the circumferential direction, the first inter-blade distance is the inter-blade distance of the first blade portion, and the second inter-blade distance is the inter-blade distance of the second blade portion, and
• wherein the plurality of blades include a plurality of first blades and a plurality of second blades,
• in a first section of the plurality of blades that is taken along a first plane perpendicular to the rotation axis, each of the plurality of first blades has a blade length greater than a blade length of each of the second blades,
• between any adjacent two of the plurality of first blades in the circumferential direction, at least associated one of the second blades is provided, and
• the plurality of second blades has a region in which a ratio of an inside diameter of the second blades that is a diameter of a circle drawn through the inner circumferential ends of the second blades to an outside diameter of the second blades that is a diameter of a circle drawn through the outer circumferential ends of the second blades is lower than or equal to 0.7.

An impeller comprising:

• a main plate configured to be driven to rotate;
• an annular side plate provided opposite to the main plate;
• and
• a plurality of blades connected to the main plate and the side plate and arranged in a circumferential direction with respect to a rotation axis of the main plate,
• wherein each of the plurality of blades has
• an inner circumferential end located closer to the rotation axis in a radial direction from the rotation axis,
• an outer circumferential end located closer to an outer circumferential side than the inner circumferential end in the radial direction,
• a sirocco blade portion formed as a forward-swept blade portion, including the outer circumferential end, and having an outlet angle that is greater than 90 degrees, and
• a turbo blade portion formed as a swept-back blade portion and including the inner circumferential end,
• wherein the plurality of blades include
• a first blade portion provided on one plate side of the main plate, and
• a second blade portion provided on an other plate side of the main plate,
• the impeller including a region in which a first inter-blade distance is greater than a second inter-blade distance, where an inter-blade distance is a distance between any adjacent two of the plurality of blades in the circumferential direction, the first inter-blade distance is the inter-blade distance of the first blade portion, and the second inter-blade distance is the inter-blade distance of the second blade portion, and
• wherein the sirocco blade portions of the plurality of blades are formed such that at end portions closer to the side plate in an axial direction of the rotation axis, a ratio of a blade inside diameter of the plurality of blades that is a diameter of a circle drawn through the inner circumferential ends of the plurality of blades to a blade outside diameter of the plurality of blades that is a diameter of a circle drawn through the outer circumferential ends of the plurality of blades is higher than or equal to 0.7.

An impeller comprising:

• a main plate configured to be driven to rotate;
• an annular side plate provided opposite to the main plate;
• and
• a plurality of blades connected to the main plate and the side plate and arranged in a circumferential direction with respect to a rotation axis of the main plate,
• wherein each of the plurality of blades has
• an inner circumferential end located closer to the rotation axis in a radial direction from the rotation axis,
• an outer circumferential end located closer to an outer circumferential side than the inner circumferential end in the radial direction,
• a sirocco blade portion formed as a forward-swept blade portion, including the outer circumferential end, and having an outlet angle that is greater than 90 degrees, and
• a turbo blade portion formed as a swept-back blade portion and including the inner circumferential end,
• wherein the plurality of blades include
• a first blade portion provided on one plate side of the main plate, and
• a second blade portion provided on an other plate side of the main plate,
• the impeller including a region in which a first inter-blade distance is greater than a second inter-blade distance, where an inter-blade distance is a distance between any adjacent two of the plurality of blades in the circumferential direction, the first inter-blade distance is the inter-blade distance of the first blade portion, and the second inter-blade distance is the inter-blade distance of the second blade portion, and
• wherein the turbo blade portions and the sirocco blade portions of the plurality of blades are formed such that at end portions closer to the side plate in an axial direction of the rotation axis, a ratio of a blade inside diameter of the plurality of blades that is a diameter of a circle drawn through the inner circumferential ends of the plurality of blades to a blade outside diameter of the plurality of blades that is a diameter of a circle drawn through the outer circumferential ends of the plurality of blades is higher than or equal to 0.7.

A multi-blade fan comprising:

• an impeller including a main plate configured to be driven to rotate, an annular side plate provided opposite to the main plate, and a plurality of blades connected to the main plate and the side plate and arranged in a circumferential direction with respect to a rotation axis of the main plate;
• a scroll casing housing the impeller, and having a peripheral wall formed into a volute shape and a side wall including a bellmouth that forms an air inlet communicating with a space defined by the main plate and the plurality of blades;
• and
• a motor provided outside the scroll casing and provided to face the first blade portion,
• wherein each of the plurality of blades has
• an inner circumferential end located closer to the rotation axis in a radial direction from the rotation axis,
• an outer circumferential end located closer to an outer circumferential side than the inner circumferential end in the radial direction,
• a sirocco blade portion formed as a forward-swept blade portion, including the outer circumferential end, and having an outlet angle that is greater than 90 degrees, and
• a turbo blade portion formed as a swept-back blade portion and including the inner circumferential end,
• wherein the plurality of blades include
• a first blade portion provided on one plate side of the main plate, and
• a second blade portion provided on an other plate side of the main plate,
• the impeller including a region in which a first inter-blade distance is greater than a second inter-blade distance, where an inter-blade distance is a distance between any adjacent two of the plurality of blades in the circumferential direction, the first inter-blade distance is the inter-blade distance of the first blade portion, and the second inter-blade distance is the inter-blade distance of the second blade portion.

A multi-blade fan comprising:

• an impeller including a main plate configured to be driven to rotate, an annular side plate provided opposite to the main plate, and a plurality of blades connected to the main plate and the side plate and arranged in a circumferential direction with respect to a rotation axis of the main plate;
• a scroll casing housing the impeller, and having a peripheral wall formed into a volute shape and a side wall including a bellmouth that forms an air inlet communicating with a space defined by the main plate and the plurality of blades,
• wherein each of the plurality of blades has
• an inner circumferential end located closer to the rotation axis in a radial direction from the rotation axis,
• an outer circumferential end located closer to an outer circumferential side than the inner circumferential end in the radial direction,
• a sirocco blade portion formed as a forward-swept blade portion, including the outer circumferential end, and having an outlet angle that is greater than 90 degrees, and
• a turbo blade portion formed as a swept-back blade portion and including the inner circumferential end,
• wherein the plurality of blades include
• a first blade portion provided on one plate side of the main plate, and
• a second blade portion provided on an other plate side of the main plate,
• the impeller including a region in which a first inter-blade distance is greater than a second inter-blade distance, where an inter-blade distance is a distance between any adjacent two of the plurality of blades in the circumferential direction, the first inter-blade distance is the inter-blade distance of the first blade portion, and the second inter-blade distance is the inter-blade distance of the second blade portion, and
• wherein the plurality of blades are formed such that a blade outside diameter of the plurality of blades that is a diameter of a circle drawn through the outer circumferential ends of the plurality of blades is larger than an inside diameter of the bellmouth, and
• each of the plurality of blades has a step portion formed at an end portion of the turbo blade portion that is closer to the side plate.

A multi-blade fan comprising:

• an impeller an impeller including a main plate configured to be driven to rotate, an annular side plate provided opposite to the main plate, and a plurality of blades connected to the main plate and the side plate and arranged in a circumferential direction with respect to a rotation axis of the main plate;
• a scroll casing housing the impeller, and having a peripheral wall formed into a volute shape and a side wall including a bellmouth that forms an air inlet communicating with a space defined by the main plate and the plurality of blades;
• and
• a motor provided outside the scroll casing and provided to face the first blade portion,
• wherein each of the plurality of blades has
• an inner circumferential end located closer to the rotation axis in a radial direction from the rotation axis,
• an outer circumferential end located closer to an outer circumferential side than the inner circumferential end in the radial direction,
• a sirocco blade portion formed as a forward-swept blade portion, including the outer circumferential end, and having an outlet angle that is greater than 90 degrees, and
• a turbo blade portion formed as a swept-back blade portion and including the inner circumferential end,
• wherein the plurality of blades include
• a first blade portion provided on one plate side of the main plate, and
• a second blade portion provided on an other plate side of the main plate,
• the impeller including a region in which a first inter-blade distance is greater than a second inter-blade distance, where an inter-blade distance is a distance between any adjacent two of the plurality of blades in the circumferential direction, the first inter-blade distance is the inter-blade distance of the first blade portion, and the second inter-blade distance is the inter-blade distance of the second blade portion, and
• wherein an inside diameter of the bellmouth is larger than a blade inside diameter of the plurality of blades that is a diameter of a circle drawn though the inner circumferential ends of the plurality of blades in a first region located closer to the main plate than a middle position in an axial direction of the rotation axis, and is smaller than a blade inside diameter of the plurality of blades that is a diameter of a circle drawn through the inner circumferential ends of the plurality of blades in a second region located closer to the side plate than the first region.