# US 12,760,744 B2 · Centrifugal fan and home appliance comprising same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,760,744 B2 - Document ID: US12760744B2 - Status: Granted - Kind: B2 - Application number: 19/028,698 - Filed: 2025-01-17 - Published: 2025-10-02 - Granted: 2026-10-13 - Earliest claimed: 2024-03-27 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Yonghun Kang; Eunkyeong Kwak; Ohjin Kwon; Gihyun Lee - Web page: https://patentgrep.com/patent/US12760744B2 ## CPC - F04D 29/282: {the leading edge of each vane being substantially parallel to the rotation axis} - F04D 29/441: {especially adapted for elastic fluid pumps} - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) ## Abstract A centrifugal fan according to an embodiment includes: a plurality of blades arranged around a rotation axis of the centrifugal fan, and a first shroud and a second shroud located at ends of the plurality of blades. The second shroud surrounds the first shroud and is spaced apart from the first shroud. The second shroud does not overlap the first shroud in a direction parallel to the rotation axis of the centrifugal fan. ## Claims ### Claim 1 A centrifugal fan comprising: a plurality of blades arranged about a rotation axis of the centrifugal fan; and a first shroud and a second shroud located at ends of the plurality of blades, wherein the second shroud is adjacent to the first shroud and surrounds the first shroud, wherein the second shroud does not overlap the first shroud in a direction parallel to the rotation axis of the centrifugal fan, wherein, in a plan view, an inner edge of the second shroud is spaced radially outward from an outer edge of the first shroud, and wherein an inner diameter of the inner edge of the second shroud is larger than an outer diameter of the outer edge of the first shroud such that a radial gap is formed between the first shroud and the second shroud. ### Claim 2 (depends on 1) The centrifugal fan of claim 1, wherein: in a plan view, the first shroud and the second shroud are separated by a first gap; one of the plurality of blades is separated from another neighboring blade by a second gap; and the first gap is connected to the second gap such that air passing through the first gap flows directly into the second gap. ### Claim 3 (depends on 1) The centrifugal fan of claim 1, wherein the first shroud and the second shroud are configured to provide a reintroduction path for air discharged from the centrifugal fan. ### Claim 4 (depends on 1) The centrifugal fan of claim 1, wherein the first shroud and the second shroud do not include undercuts to enable top and bottom separation of a mold for injection molding of the centrifugal fan. ### Claim 5 (depends on 1) The centrifugal fan of claim 1, wherein, when viewed in a direction parallel to the rotation axis, a distance between the first shroud and the second shroud is greater than 0, and less than or equal to 2% of an outer diameter of the centrifugal fan. ### Claim 6 (depends on 1) The centrifugal fan of claim 1, wherein a flow inlet angle of each of the plurality of blades is 95 degrees or more and 105 degrees or less, the flow inlet angle being defined as an angle between a direction of fluid inflow at a leading edge of the blade and a chord line connecting a center of the leading edge and a center of a trailing edge of the blade. ### Claim 7 (depends on 1) The centrifugal fan of claim 1, wherein a flow exit angle of each of the plurality of blades is 140 degrees or more and 150 degrees or less, the flow exit angle being defined as an angle between a direction of fluid outflow at a trailing edge of the blade and a chord line connecting a center of the leading edge and a center of a trailing edge of the blade. ### Claim 8 (depends on 1) The centrifugal fan of claim 1, wherein a ratio of a height of a maximum bending point of the plurality of blades to a chord length of the plurality of blades is 0.17 or more and 0.2 or less. ### Claim 9 (depends on 1) The centrifugal fan of claim 1, wherein a ratio of an inner diameter of the plurality of blades to a chord length of the plurality of blades is 2.5 or more and 3.0 or less. ### Claim 10 (depends on 1) The centrifugal fan of claim 1, comprising: a hub plate on which the plurality of blades are disposed on a side; a plurality of other blades disposed on another side of the hub plate and arranged about the rotation axis; and a third shroud and a fourth shroud located at ends of the plurality of another blades, and wherein: the fourth shroud surrounds the third shroud and is spaced apart from the third shroud; and the fourth shroud does not overlap the third shroud in the direction parallel to the rotation axis of the centrifugal fan. ### Claim 11 A home appliance comprising a centrifugal fan including: a plurality of blades arranged about a rotation axis of the centrifugal fan; and a first shroud and a second shroud located at ends of the plurality of blades, wherein the second shroud is adjacent to the first shroud and surrounds the first shroud, wherein the second shroud does not overlap the first shroud in a direction parallel to the rotation axis of the centrifugal fan, wherein, in a plan view, an inner edge of the second shroud is spaced radially outward from an outer edge of the first shroud, and wherein an inner diameter of the inner edge of the second shroud is larger than an outer diameter of the outer edge of the first shroud such that a radial gap is formed between the first shroud and the second shroud. ### Claim 12 (depends on 11) The home appliance of claim 11, wherein: in a plan view, the first shroud and the second shroud are separated by a first gap; one of the plurality of blades is separated from another neighboring blade by a second gap; and the first gap is connected to the second gap such that air passing through the first gap flows directly into the second gap. ### Claim 13 (depends on 11) The home appliance of claim 11, wherein the first shroud and the second shroud are configured to provide a reintroduction path for air discharged from the centrifugal fan. ### Claim 14 (depends on 11) The home appliance of claim 11, wherein the first shroud and the second shroud do not include undercuts to enable top and bottom separation of a mold for injection molding of the centrifugal fan. ### Claim 15 (depends on 11) The home appliance of claim 11, wherein, when viewed in a direction parallel to the rotation axis, a distance between the first shroud and the second shroud is 2.5 mm or less. ### Claim 16 (depends on 11) The home appliance of claim 11, wherein: a flow inlet angle of each of the plurality of blades is 95 degrees or more and 105 degrees or less, the flow inlet angle being defined as an angle between a direction of fluid inflow at a leading edge of the blade and a chord line connecting a center of the leading edge and a center of a trailing edge of the blade; and a flow exit angle of each of the plurality of blades is 140 degrees or more and 150 degrees or less, the flow exit angle being defined as an angle between a direction of fluid outflow at a trailing edge of the blade and a chord line connecting a center of the leading edge and a center of a trailing edge of the blade. ### Claim 17 (depends on 11) The home appliance of claim 11, wherein a ratio of a height of a maximum bending point of the plurality of blades to a chord length of the plurality of blades is 0.17 or more and 0.2 or less. ### Claim 18 (depends on 11) The home appliance of claim 11, wherein a ratio of an inner diameter of the plurality of blades to a chord length of the plurality of blades is 2.5 or more and 3.0 or less. ### Claim 19 (depends on 11) The home appliance of claim 11, wherein the centrifugal fan includes: a hub plate on which the plurality of blades are disposed on a side; a plurality of other blades disposed on another side of the hub plate and arranged around the rotation axis; and a third shroud and a fourth shroud located at ends of the plurality of another blades, and wherein: the fourth shroud surrounds the third shroud and is spaced apart from the third shroud; and the fourth shroud does not overlap the third shroud in the direction parallel to the rotation axis of the centrifugal fan. ### Claim 20 (depends on 11) The home appliance of claim 11, comprising: a dryer, a laundry dryer, an air conditioner, a range hood, or an air purifier.