Centrifugal air-sending device and air-conditioning apparatus

Patent metadata

Field	Value
Publication number	US-12320363-B2
Application number	US-202018044091-A
Country	US
Kind code	B2
Filing date	Oct 22, 2020
Priority date	Oct 22, 2020
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

A centrifugal air-sending device has blades that each have a vane length in a first region that is greater than a vane length in a second region, and are each formed such that a proportion for which a turbo vane portion accounts is higher in a radial direction than a proportion for which a sirocco vane portion accounts in the first region and the second region. The blades that are located closer to an outer circumference than is a blade inner diameter of inner circumferential ends of the blades at end portions of the blades that are close to a side plate in an axial direction are defined as a blade outer circumferential portion that is formed such that a vane thickness of each of the blades in decreased in the radial direction from an inner circumference toward the outer circumference.

First claim

The invention claimed is:

1. A centrifugal air-sending device comprising:
an impeller that has a main plate that is to be driven to rotate, a side plate that is ring-shaped and located such that the side plate faces the main plate, and a plurality of blades that each have one end connected to the main plate and an other end connected to the side plate and are arranged in a circumferential direction centered on a rotation axis of the main plate that is virtual; and
a scroll casing that houses the impeller and has a circumferential wall that is scroll-shaped and a side wall that has a bell mouth that forms a suction port that communicates with a space defined by the main plate and the plurality of blades,
the plurality of blades each having
an inner circumferential end that is closer to the rotation axis than is an outer circumferential end in a radial direction centered on the rotation axis,
the outer circumferential end that is closer to an outer circumference than is the inner circumferential end in the radial direction,
a sirocco vane portion that includes the outer circumferential end and forms a forward-curved blade at which an outlet angle is formed larger than 90 degrees,
a turbo vane portion that includes the inner circumferential end and forms a backward-curved blade,
a first region that is located closer to the main plate than is an intermediate position between the main plate and the side plate in an axial direction of the rotation axis, and
a second region that is located closer to the side plate than is the first region,
the plurality of blades each having a vane length in the first region that is greater than a vane length in the second region,
the plurality of blades being each formed such that a proportion for which the turbo vane portion accounts is higher in the radial direction than a proportion for which the sirocco vane portion accounts in the first region and the second region,
in a case in which portions of the plurality of blades that are located closer to the outer circumference than is a blade inner diameter of the respective inner circumferential ends of the plurality of blades at end portions of the plurality of blades that are close to the side plate in the axial direction are defined as a blade outer circumferential portion, the blade outer circumferential portion is formed such that a vane thickness of each of the plurality of blades is decreased in the radial direction from an inner circumference toward the outer circumference.

2. The centrifugal air-sending device of claim 1 , wherein the centrifugal air-sending device is formed such that the vane thickness at each of only the sirocco vane portions of the plurality of blades is decreased in the radial direction from the inner circumference toward the outer circumference.

3. The centrifugal air-sending device of claim 1 , wherein the plurality of blades are formed such that the vane thickness at each of the turbo vane portions of the plurality of blades is constant in each section in the axial direction from the inner circumference toward the outer circumference of the impeller.

4. The centrifugal air-sending device of claim 1 , wherein the plurality of blades are each formed such that the turbo vane portion and the sirocco vane portion are separated from each other in the radial direction.

5. The centrifugal air-sending device of claim 1 , wherein
the plurality of blades are each formed such that a blade outer diameter of the respective outer circumferential ends of the plurality of blades is larger than an inner diameter of the bell mouth, and,
in a case in which portions of the plurality of blades that are located closer to the outer circumference than is an inner circumferential side end portion that is an end portion of the bell mouth that is located closest to the inner circumference in the radial direction are defined as an outer circumferential region portion,
the outer circumferential region portion is formed such that the proportion for which the sirocco vane portion accounts is higher in the radial direction than the proportion for which the turbo vane portion accounts in the first region and the second region.

6. An air-conditioning apparatus comprising the centrifugal air-sending device of claim 1 .

7. An air-conditioning apparatus, comprising:
the centrifugal air-sending device of claim 1 ;
a heat exchanger located such that the heat exchanger faces the centrifugal air-sending device; and
a housing that houses the centrifugal air-sending device and the heat exchanger and in which a housing inlet port through which air that is to be sucked into the centrifugal air-sending device flows is formed and a housing outlet port through which air that is discharged from the centrifugal air-sending device and has passed through the heat exchanger flows is formed, wherein
the scroll casing has a tongue portion that separates an airflow blown out from the impeller, and,
in a case in which the centrifugal air-sending device is viewed in the axial direction of the rotation axis, a portion divided by the rotation axis and in which the tongue portion is located is defined as a tongue-portion including section and a portion divided by the rotation axis and located closer to the housing inlet port than is the tongue-portion including section is defined as an inlet-port facing section, and a distance between an inner circumferential edge portion and an outer circumferential edge portion of the bell mouth in the radial direction in the tongue-portion including section is defined as a first distance and a distance between the inner circumferential edge portion and the outer circumferential edge portion of the bell mouth in the radial direction in the inlet-port facing section is defined as a second distance, the scroll casing is formed such that the first distance is smaller than the second distance.

8. The air-conditioning apparatus of claim 7 , wherein,
in a direction in which air flows between the impeller and the circumferential wall, a ratio at which a distance between the impeller and the circumferential wall is increased from an upstream portion toward a downstream portion is defined as a scroll enlargement ratio, the scroll enlargement ratio at a portion of the scroll casing in the tongue-portion including section is defined as a first enlargement ratio, and the scroll enlargement ratio at a portion of the scroll casing in the inlet-port facing section is defined as a second enlargement ratio,
the scroll casing is formed such that the second enlargement ratio is higher than the first enlargement ratio.

9. An air-conditioning apparatus, comprising:
the centrifugal air-sending device of claim 1 ;
a heat exchanger located such that the heat exchanger faces the centrifugal air-sending device; and
a housing that houses the centrifugal air-sending device and the heat exchanger and in which a housing inlet port through which air that is to be sucked into the centrifugal air-sending device flows is formed and a housing outlet port through which air that is discharged from the centrifugal air-sending device and has passed through the heat exchanger flows is formed, wherein
the scroll casing has a tongue portion that separates an airflow blown out from the impeller, and,
in a case in which the centrifugal air-sending device is viewed in the axial direction of the rotation axis, a portion divided by the rotation axis and in which the tongue portion is located is defined as a tongue-portion including section and a portion divided by the rotation axis and located closer to the housing inlet port than is the tongue-portion including section is defined as an inlet-port facing section, and, in a direction in which air flows between the impeller and

Assignees

• Mitsubishi Electric Corp

Inventors

• Teramoto Takuya
• Hayashi Hiroyasu
• Horie Ryo
• Akari Yoshitaka
• Yamaguchi Takashi
• Michikami Kazuya
• Yamatani Takahiro
• Takagi Masahiko
• Watanabe Kazuki
• Seki Hidetoshi

Classifications

• F24F1/0022

  Centrifugal or radial fans · CPC title

• F04D29/582

  specially adapted for elastic fluid pumps · CPC title

• F04D29/4206

  especially adapted for elastic fluid pumps · CPC title

• F04D17/08

  Centrifugal pumps · CPC title

• F05D2240/303

  related to the leading edge of a rotor blade · CPC title