# US 11,441,576 B2 · Double-suction centrifugal pump > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,576 B2 - Document ID: US11441576B2 - Status: Granted - Kind: B2 - Application number: 17/252,932 - Filed: 2019-05-29 - Published: 2021-04-22 - Granted: 2022-09-13 - Earliest claimed: 2018-06-22 - Assignees: Ebara Corporation - Applicants: Ebara Corporation - Inventors: Soichiro Ogawa; Hiroyuki Kawasaki; Takayuki Miyamoto - Web page: https://patentgrep.com/patent/US11441576B2 ## CPC - F04D 29/426: {especially adapted for liquid pumps} - F04D 29/4233: {with volutes extending mainly in axial or radially inward direction} - F04D 29/4273: {suction eyes} - F04D 29/4293: {Details of fluid inlet or outlet} - F04D 1/006: {double suction pumps} - F04D 29/281: {for fans or blowers} - F05D 2240/126: Baffles or ribs - F05D 2260/941: particularly aimed at mechanical or thermal stress reduction - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract The present invention relates to a reinforcing structure for a casing accommodating an impeller. A double-suction centrifugal pump includes: a rotational shaft (1); an impeller (2) secured to the rotational shaft (1); a casing (3) that accommodates the impeller (2) therein; and legs (5) secured to the casing (3). The casing (3) includes a suction volute (20) that communicates with a suction port (6), the casing (3) includes an upper casing (3a) and a lower casing (3b) fastened to each other, at least one rib (28A, 28B, 28C) is provided on each of both side surfaces of the lower casing (3b) constituting the suction volute (20), the rib (28A, 28B, 28C) extends in a radial direction of the rotational shaft (1) when viewed from an axial direction of the rotational shaft (1), and the rib (28A, 28B, 28C) is separated from the legs (5). ## Claims ### Claim 1 A double-suction centrifugal pump comprising: a rotational shaft; an impeller secured to the rotational shaft; a casing that accommodates the impeller therein; and legs secured to the casing, wherein the casing includes a suction volute that communicates with a suction port, the casing includes an upper casing and a lower casing fastened to each other, at least one rib is provided on each of both side surfaces of the lower casing constituting the suction volute, the at least one rib extends in a radial direction of the rotational shaft when viewed from an axial direction of the rotational shaft, and the at least one rib is separated from the legs, wherein the at least one rib provided on each of both side surfaces of the suction volute comprises a plurality of ribs, and wherein the plurality of ribs are located in a fan-shaped area whose central line coincides with a vertical line passing through a central axis of the rotational shaft when viewed from the axial direction of the rotational shaft, and a central angle of the fan-shaped area is 140 degrees or less. ### Claim 2 (depends on 1) The double-suction centrifugal pump according to claim 1, wherein the at least one rib has a height that gradually decreases with a distance from an upper end of the at least one rib. ### Claim 3 (depends on 1) The double-suction centrifugal pump according to claim 1, wherein the lower casing has a semicircular annular portion extending along a circumferential surface of the rotational shaft, and an upper end of the at least one rib is connected to the semicircular annular portion. ### Claim 4 (depends on 1) The double-suction centrifugal pump according to claim 1, wherein the at least one rib has a lower end smoothly connected to an outer surface of the lower casing. ### Claim 5 (depends on 1) The double-suction centrifugal pump according claim 1, wherein at least one of the plurality of ribs has a cross section different from a cross section of another one of the plurality of ribs. ### Claim 6 (depends on 1) The double-suction centrifugal pump according to claim 1, wherein the legs are located on extension lines of the plurality of ribs. ### Claim 7 (depends on 1) The double-suction centrifugal pump according to claim 1, further comprising at least one upper rib provided on an outer surface of the upper casing. ### Claim 8 (depends on 1) The double-suction centrifugal pump according to claim 1, further comprising at least one bottom rib provided on a bottom of the lower casing. ### Claim 9 A double-suction centrifugal pump comprising: a rotational shaft; an impeller secured to the rotational shaft; a casing that accommodates the impeller therein; and legs secured to the casing, wherein the casing includes a suction volute that communicates with a suction port, the casing includes an upper casing and a lower casing fastened to each other, at least one rib is provided on each of both side surfaces of the lower casing constituting the suction volute, the at least one rib extends in a radial direction of the rotational shaft when viewed from an axial direction of the rotational shaft, and the at least one rib is separated from the legs, wherein the at least one rib provided on each of both side surfaces of the suction volute comprises a plurality of ribs, and wherein the plurality of ribs have different lengths, and a respective rib closer to the suction port is longer.