# US 10,309,412 B2 · Centrifugal fan, air-conditioning apparatus, and method of manufacturing centrifugal fan > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,309,412 B2 - Document ID: US10309412B2 - Status: Granted - Kind: B2 - Application number: 14/889,963 - Filed: 2014-04-16 - Published: 2016-04-28 - Granted: 2019-06-04 - Earliest claimed: 2013-06-14 - Assignees: Mitsubishi Electric Corporation - Applicants: Mitsubishi Electric Corporation - Inventors: Makoto Kurihara; Kohei Tsunetomo; Takehiro Hayashi - Web page: https://patentgrep.com/patent/US10309412B2 ## CPC - F04D 29/281: {for fans or blowers} - B29C 65/1635: {at least passing through one of the parts to be joined, i.e. laser transmission welding} - B29C 65/1654: {scanning at least one of the parts to be joined} - B29C 65/1664: {making use of several radiators} - B29C 66/124: {Tongue and groove joints} - B29C 66/12469: {being asymmetric} - B29C 66/30223: {said melt initiators being rib-like} - B29C 66/5346: {said single elements being substantially flat} - B29C 66/543: {joining more than two hollow-preforms to form said hollow articles} - F04D 25/08: the working fluid being air, e.g. for ventilation - F04D 29/023: {especially adapted for elastic fluid pumps} - F04D 29/30: Vanes - F04D 29/624: {especially adapted for elastic fluid pumps} - F04D 29/626: {Mounting or removal of fans} - F24F 1/0022: Centrifugal or radial fans - B29C 66/5344: {said single elements being substantially annular, i.e. of finite length, e.g. joining flanges to tube ends (B29C66/5346 takes precedence)} - B29L 2031/08: Blades for rotors, stators, fans, turbines or the like, e.g. screw propellers - F05D 2230/234: Laser welding - F05D 2260/96: Preventing, counteracting or reducing vibration or noise - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02) - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract A centrifugal fan 1 includes a main plate 10, a shroud 20, and a plurality of blades 30 provided between the main plate 10 and the shroud 20. The blade 30 includes abutting surfaces 34, 35a, and 35b that respectively abut on abutted surfaces 12a, 22a, and another abutted surface formed on at least one of the main plate 10 and the shroud 20. The abutting surfaces 34, 35a, and 35b includes projections 36, 37a, and 37b formed thereon, respectively, and extending in a straight or curved line. The abutting surfaces 34, 35a, and 35b and the abutted surfaces 12a, 22a, and the other abutted surface are respectively welded to each other by laser beams 40 and 41 respectively directed onto and moved along the projection 36 and the projections 37a and 37b. ## Claims ### Claim 1 A centrifugal fan comprising: a main plate rotatably driven by a fan motor; a shroud facing the main plate; and a plurality of blades provided between the main plate and the shroud, wherein the centrifugal fan is configured to suck gas in a direction of a rotation axis and blow out the gas in a direction intersecting the rotation axis, each of the plurality of blades includes an abutting surface that abuts on an abutted surface formed on at least one of the main plate and the shroud, the abutting surface has an edge and a central portion, the abutting surface includes a projection that extends in a straight line or a curved line, and the abutting surface and the abutted surface are welded to each other by a laser beam directed onto and moved along the projection, each of the plurality of blades further includes a first member constituting at least a part of one blade surface of each of the plurality of blades, and a second member having a surface portion facing the first member and constituting at least a part of an other blade surface of each of the plurality of blades and a peripheral edge extending from an end of the surface portion toward an end of the first member, the second member forming a hollow space between the first member and the second member, the abutting surface is formed on the peripheral edge of the second member, the projection is formed closer to the surface portion of the second member than the central portion of the abutting surface in a direction of extension of the peripheral edge of the second member, and the projection is formed apart from both the edge of the abutting surface and the central portion of the abutting surface in the direction of extension of the peripheral edge of the second member. ### Claim 2 (depends on 1) The centrifugal fan of claim 1, wherein a cross-sectional shape of the projection is either triangular, rectangular, or arcuate, and a width of the projection is between 50% and 150% of a spot diameter of the laser beam. ### Claim 3 (depends on 1) The centrifugal fan of claim 1, wherein each of the plurality of blades is made of a first resin material, at least one of the main plate and the shroud on which the abutted surface is formed is made of a second resin material, an absorbance of the laser beam of the first resin material is higher than an absorbance of the laser beam of the second resin material, and a transmittance of the laser beam of the second resin material is higher than a transmittance of the laser beam of the first resin material. ### Claim 4 (depends on 1) The centrifugal fan of claim 1, wherein each of the plurality of blades has a three-dimensional blade shape that is twisted between the main plate and the shroud. ### Claim 5 (depends on 1) An air-conditioning apparatus including the centrifugal fan of claim 1. ### Claim 6 A method of manufacturing a centrifugal fan having a main plate rotatably driven by a fan motor, a shroud facing the main plate, and a plurality of blades provided between the main plate and the shroud, the centrifugal fan being configured to suck gas in a direction of a rotation axis and blow out the gas in a direction intersecting the rotation axis, the method comprising: forming a projection that extends in a straight line or a curved line on an abutting surface formed on each of the plurality of blades for abutting on an abutted surface formed on at least one of the main plate and the shroud, the abutting surface has an edge and a central portion; placing the projection formed on the abutting surface in abutment with the abutted surface; and welding the abutting surface and the abutted surface to each other by directing a laser beam onto the projection and moving the laser beam along the projection, wherein each of the plurality of blades further includes a first member constituting at least a part of one blade surface of each of the plurality of blades, and a second member having a surface portion facing the first member and constituting at least a part of an other blade surface of each of the plurality of blades and a peripheral edge extending from an end of the surface portion toward an end of the first member, the second member forming a hollow space between the first member and the second member, the abutting surface is formed on the peripheral edge of the second member, the projection is formed closer to the surface portion of the second member than the central portion of the abutting surface in a direction of extension of the peripheral edge of the second member, and the projection is formed apart from both the edge of the abutting surface and the central portion of the abutting surface in the direction of extension of the peripheral edge of the second member. ### Claim 7 (depends on 6) The method of manufacturing the centrifugal fan of claim 6, the method further comprising pressing the main plate and the shroud in mutually facing directions with the plurality of blades positioned therebetween to bring the abutting surfaces and the abutted surfaces into close contact after the welding of the abutting surface and the abutted surface. ### Claim 8 (depends on 1) The centrifugal fan according to claim 1, wherein the abutting surface is a continuous surface that includes the central portion and the edge of the abutting surface, and the projection is formed on the abutting surface between the edge and the central portion of the abutting surface. ### Claim 9 (depends on 6) The method of manufacturing the centrifugal fan of claim 6, wherein the abutting surface is a continuous surface that includes the central portion and the edge of the abutting surface, and the projection is formed on the abutting surface between the edge and the central portion of the abutting surface.