# US 2013/0156569 A1 · Centrifugal fan device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0156569 A1 - Document ID: US20130156569A1 - Status: Published application - Kind: A1 - Application number: 13/676,155 - Filed: 2012-11-14 - Published: 2013-06-20 - Earliest claimed: 2011-12-15 - Assignees: Nidec Corporation - Inventors: Kazushi ISHIKAWA - Web page: https://patentgrep.com/patent/US20130156569A1 ## CPC - F04D 17/08: Centrifugal pumps - F04D 29/162: {of a centrifugal flow wheel} - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) ## Abstract A centrifugal fan device includes an impeller supported to rotate about a center axis extending in an up-down direction; a motor arranged to rotate the impeller; and a housing arranged to surround the impeller. The housing includes an intake portion positioned above the impeller and an exhaust portion positioned radially outward of the impeller. The impeller includes a base extending in a direction orthogonal to the center axis, a ring-shaped shroud positioned above the base and having a diameter which decreases as it goes upward, and a plurality of blades arranged between the base and the shroud. The housing further includes a plurality of ribs protruding from an inner surface of the intake portion toward the shroud. ## Claims ### Claim 1 A centrifugal fan device, comprising: an impeller supported to rotate about a center axis extending in an up-down direction; a motor arranged to rotate the impeller; and a housing arranged to surround the impeller; wherein the housing includes an intake portion positioned above the impeller and an exhaust portion positioned radially outward of the impeller; the impeller includes a base extending in a direction perpendicular or substantially perpendicular to the center axis, a ring-shaped shroud positioned above the base and having a diameter which decreases as it goes upward, and a plurality of blades existing between the base and the shroud; the intake portion includes a cylinder portion positioned radially inward of an upper end portion of the shroud to extend in an axial direction, a top plate portion extending radially outward from an upper end portion of the cylinder portion and an outer shell portion extending downward and radially outward from a radial outer edge of the top plate portion; and the housing further includes a plurality of ribs protruding from an inner surface of the intake portion toward the shroud. ### Claim 2 (depends on 1) The device of claim 1, wherein each of the ribs includes a radial inner edge positioned radially outward of the upper end portion of the shroud, the ribs being connected to a lower surface of the top plate portion. ### Claim 3 (depends on 1) The device of claim 1, wherein, when seen in a vertical cross section including the center axis and the ribs, a lower edge of each of the ribs is joined to a lower surface of the outer shell portion, the outer shell portion including a section positioned radially outward of the ribs, the section of the outer shell portion including a lower surface positioned lower than a lower end portion of each of the ribs. ### Claim 4 (depends on 1) The device of claim 1, wherein each of the ribs include a first rib positioned radially outward of the upper end portion of the shroud and a second rib positioned radially inward of the upper end portion of the shroud. ### Claim 5 (depends on 4) The device of claim 4, wherein each of the ribs includes a cutout arranged between the first rib and the second rib. ### Claim 6 (depends on 4) The device of claim 4, wherein the second rib is connected to a lower surface of the top plate portion. ### Claim 7 (depends on 1) The device of claim 1, wherein a total number of the ribs of the housing does not equal any one of a total number of the blades of the impeller, a total number of poles of the motor, and a total number of slots of the motor. ### Claim 8 (depends on 1) The device of claim 1, wherein the ribs include a ring-shaped rib positioned radially outward of the upper end portion of the shroud and extending in a circumferential direction, the ring-shaped rib being connected to two or more of the ribs. ### Claim 9 (depends on 1) The device of claim 1, wherein the cylinder portion includes a lower end portion positioned lower than the upper end portion of the shroud. ### Claim 10 (depends on 2) The device of claim 2, wherein a radial distance d1 between a radial inner edge of each of the ribs and an outer circumferential surface of the upper end portion of the shroud, a radial distance d2 between a radial inner surface of the outer shell portion and the outer circumferential surface of the upper end portion of the shroud, and an axial distance d3 between a lower surface of a section of the outer shell portion lying radially outward of the ribs and an upper surface of the shroud, satisfy a relationship of d2>d3>d1. ### Claim 11 (depends on 10) The device of claim 10, wherein, when seen in a vertical cross section including the center axis and the ribs, a lower edge of each of the ribs is joined to a lower surface of the outer shell portion, and the lower surface of the section of the outer shell portion lying radially outward of the ribs is positioned lower than a lower end portion of each of the ribs. ### Claim 12 (depends on 1) The device of claim 1, wherein the top plate portion includes a planar upper surface. ### Claim 13 (depends on 1) The device of claim 1, wherein the housing is a resin molded article. ### Claim 14 A centrifugal fan device, comprising: an impeller supported to rotate about a center axis extending in an up-down direction; a motor arranged to rotate the impeller; and a housing arranged to surround the impeller; wherein the housing includes an intake portion positioned above the impeller and an exhaust portion positioned radially outward of the impeller; the impeller includes a lower impeller member and an upper impeller member positioned above the lower impeller member; and one of the lower impeller member and the upper impeller member includes a plurality of recesses, the other of the lower impeller member and the upper impeller member including a plurality of protrusions being fitted to the recesses; the recesses includes a single different-diameter recess differing in diameter from the remaining recesses, the protrusions including a single different-diameter protrusion differing in diameter from the remaining protrusions, the different-diameter protrusion fitted to the different-diameter recess. ### Claim 15 (depends on 14) The device of claim 14, wherein the single different-diameter recess is a small-diameter recess smaller in diameter than the remaining recesses, the single different-diameter protrusion being a small-diameter protrusion smaller in diameter than the remaining protrusions. ### Claim 16 (depends on 14) The device of claim 14, wherein the single different-diameter recess is a large-diameter recess larger in diameter than the remaining recesses, the single different-diameter protrusion being a large-diameter protrusion larger in diameter than the remaining protrusions. ### Claim 17 A centrifugal fan device manufacturing method comprising: providing a centrifugal fan device including an impeller supported to rotate about a center axis extending in an up-down direction, a motor arranged to rotate the impeller and a housing arranged to surround the impeller, the housing including an intake portion positioned above the impeller and an exhaust portion positioned radially outward of the impeller, the impeller including a lower impeller member and an upper impeller member positioned above the lower impeller member; inspecting gravity center deviations of the lower impeller member and the upper impeller member; setting positions of a single different-diameter recess and a single different-diameter protrusion such that, when the lower and upper impeller members are combined together, the gravity center deviations of the lower and upper impeller members are in the substantially opposite directions; and combining the lower and upper impeller members such that the single different-diameter recess and the single different-diameter protrusion are aligned with each other.