# US 11,905,969 B2 · Scroll structure of centrifugal compressor and centrifugal compressor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,905,969 B2 - Document ID: US11905969B2 - Status: Granted - Kind: B2 - Application number: 17/614,891 - Filed: 2019-06-05 - Published: 2022-07-28 - Granted: 2024-02-20 - Earliest claimed: 2019-06-05 - Assignees: Mitsubishi Heavy Industries Engine & Turbocharger, Ltd. - Applicants: Mitsubishi Heavy Industries Engine & Turbocharger, Ltd. - Inventors: Kenichiro Iwakiri - Web page: https://patentgrep.com/patent/US11905969B2 ## CPC - F04D 29/4206: {especially adapted for elastic fluid pumps} - F04D 29/44: Fluid-guiding means, e.g. diffusers - F02B 39/00: Component parts, details, or accessories relating to, driven charging or scavenging pumps, not provided for in groups F02B33/00 - F02B37/00 - F04D 17/10: for compressing or evacuating - F04D 29/428: {Discharge tongues (F04D17/04 takes precedence)} - F05D 2250/181: ridged - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract A scroll structure of a centrifugal compressor according to an embodiment is a scroll structure of a centrifugal compressor having a scroll passage formed in spiral shape, comprising: a tongue portion separating the scroll passage from an outlet passage connected to the downstream side of the scroll passage at the most downstream position of the scroll passage in a passage connecting portion where a winding start portion and a winding end portion of the scroll passage intersect; and a ridge portion protruding from an inner peripheral surface of the scroll passage on the axially downstream side of the centrifugal compressor toward the axially upstream side of the centrifugal compressor, with a protruding height toward the axially upstream side gradually increasing toward the tongue portion from a starting position that is located upstream from the tongue portion in the scroll passage. The starting position is a position at an angle of 8 degrees or less in the circumferential direction of the centrifugal compressor from the tongue portion toward the upstream side of the scroll passage. ## Claims ### Claim 1 A scroll structure of a centrifugal compressor having a scroll passage formed in spiral shape and having a larger dimension in an axial direction of the centrifugal compressor at a winding end portion of the scroll passage than at a winding start portion of the scroll passage, comprising: a tongue portion separating the scroll passage from an outlet passage connected to a downstream side of the scroll passage at a most downstream position of the scroll passage in a passage connecting portion where the winding start portion and the winding end portion intersect; and a ridge portion protruding from an inner peripheral surface of the scroll passage on an axially downstream side of the centrifugal compressor toward an axially upstream side of the centrifugal compressor, wherein a protruding height of the ridge portion protruding toward the axially upstream side gradually increases toward the tongue portion from a starting position that is located upstream from the tongue portion in the scroll passage, and wherein a circumferential length of the tongue portion of the centrifugal compressor from the winding start portion to the tongue portion is longer than the protruding height, wherein the starting position is a position at an angle of 8 degrees or less in a circumferential direction of the centrifugal compressor from the tongue portion toward an upstream side of the scroll passage. ### Claim 2 (depends on 1) The scroll structure of a centrifugal compressor according to claim 1, wherein a flow passage shape of the scroll passage in a cross-section extending in a direction perpendicular to a centerline of the scroll passage is not circular in the cross-section including the tongue portion, wherein a flow passage shape of the outlet passage in a cross-section extending in a direction perpendicular to a centerline of the outlet passage approaches circular as the outlet passage extends downstream from a connecting position with the scroll passage, and wherein a position where the flow passage shape of the outlet passage changes from a non-circular shape to a circular shape is downstream of the outlet passage from the connecting position by a distance equal to or greater than a passage height at the winding end portion along an axial direction of the centrifugal compressor. ### Claim 3 (depends on 1) A centrifugal compressor, comprising the scroll structure of a centrifugal compressor according to claim 1. ### Claim 4 (depends on 1) The scroll structure of a centrifugal compressor according to claim 1, wherein the protruding height in a position at an angle of 4 degrees in a circumferential direction of the centrifugal compressor from the tongue portion toward an upstream side of the scroll passage is 10% or less of a height dimension of the scroll passage at the winding start portion along an axial direction of the centrifugal compressor. ### Claim 5 (depends on 1) The scroll structure of a centrifugal compressor according to claim 1, wherein the protruding height is 30% or less of a height dimension of the scroll passage at the winding start portion along an axial direction of the centrifugal compressor. ### Claim 6 (depends on 1) The scroll structure of a centrifugal compressor according to claim 1, wherein the curvature radius of a curve connecting an apex of the ridge portion defining the protruding height from the tongue portion to the starting position is located on the axially, upstream side, and wherein the curvature radius gradually increases from the tongue portion to the starting position in at least a portion of the apex. ### Claim 7 A scroll structure of a centrifugal compressor having a scroll passage formed in spiral shape and having a larger dimension in an axial direction of the centrifugal compressor at a winding end portion of the scroll passage than at a winding start portion of the scroll passage, comprising: a tongue portion separating the scroll passage from an outlet passage connected to a downstream side of the scroll passage at a most downstream position of the scroll passage in a passage connecting portion where the winding start portion and the winding end portion intersect; and a ridge portion protruding from an inner peripheral surface of the scroll passage on an axially downstream side of the centrifugal compressor toward an axially upstream side of the centrifugal compressor, wherein a protruding height of the ridge portion protruding toward the axially upstream side gradually increases toward the tongue portion from a starting position that is located upstream from the tongue portion in the scroll passage, and wherein a circumferential length of the tongue portion of the centrifugal compressor from the winding start portion to the tongue portion is longer than the protruding height, wherein the protruding height in a position at an angle of 4 degrees in a circumferential direction of the centrifugal compressor from the tongue portion toward an upstream side of the scroll passage is 10% or less of a height dimension of the scroll passage at the winding start portion along an axial direction of the centrifugal compressor. ### Claim 8 (depends on 7) The scroll structure of a centrifugal compressor according to claim 7 wherein a flow passage shape of the scroll passage in a cross-section extending in a direction perpendicular to a centerline of the scroll passage is not circular in the cross-section including the tongue portion, wherein a flow passage shape of the outlet passage in a cross-section extending in a direction perpendicular to a centerline of the outlet passage approaches circular as the outlet passage extends downstream from a connecting position with the scroll passage, and wherein a position where the flow passage shape of the outlet passage changes from a non-circular shape to a circular shape is downstream of the outlet passage from the connecting position by a distance equal to or greater than a passage height at the winding end portion along an axial direction of the centrifugal compressor. ### Claim 9 (depends on 7) A centrifugal compressor, comprising the scroll structure of a centrifugal compressor according to claim 7. ### Claim 10 A scroll structure of a centrifugal compressor having a scroll passage formed in spiral shape and formed so that a cross-sectional area of the scroll passage increases from a winding start portion of the scroll passage to a winding end portion of the scroll passage, comprising: a tongue portion separating the scroll passage from an outlet passage connected to a downstream side of the scroll passage at a most downstream position of the scroll passage in a passage connecting portion where the winding start portion and the winding end portion intersect; and a ridge portion protruding from an inner peripheral surface of the scroll passage on an axially downstream side of the centrifugal compressor toward an axially upstream side of the centrifugal compressor, wherein a protruding height of the ridge portion protruding toward the axially upstream side gradually increases toward the tongue portion from a starting position that is located upstream from the tongue portion in the scroll passage, wherein the protruding height is 30% or less of a height dimension along an axial direction of the centrifugal compressor at a position where the cross-sectional area of the scroll flow passage is a smallest. ### Claim 11 (depends on 10) The scroll structure of a centrifugal compressor according to claim 10 wherein a flow passage shape of the scroll passage in a cross-section extending in a direction perpendicular to a centerline of the scroll passage is not circular in the cross-section including the tongue portion, wherein a flow passage shape of the outlet passage in a cross-section extending in a direction perpendicular to a centerline of the outlet passage approaches circular as the outlet passage extends downstream from a connecting position with the scroll passage, and wherein a position where the flow passage shape of the outlet passage changes from a non-circular shape to a circular shape is downstream of the outlet passage from the connecting position by a distance equal to or greater than a passage height at the winding end portion along an axial direction of the centrifugal compressor. ### Claim 12 (depends on 10) A centrifugal compressor, comprising the scroll structure of a centrifugal compressor according to claim 10. ### Claim 13 A scroll structure of a centrifugal compressor having a scroll passage formed in spiral shape, comprising: a tongue portion separating the scroll passage from an outlet passage connected to a downstream side of the scroll passage at a most downstream position of the scroll passage in a passage connecting portion where a winding start portion and a winding end portion of the scroll passage intersect; and a ridge portion protruding from an inner peripheral surface of the scroll passage on an axially downstream side of the centrifugal compressor toward an axially upstream side of the centrifugal compressor, wherein a protruding height of the ridge portion protruding toward the axially upstream side gradually increases toward the tongue portion from a starting position that is located upstream from the tongue portion in the scroll passage, wherein a curvature radius of a curve connecting an apex of the ridge portion defining the protruding height from the tongue portion to the starting position is located on the axially upstream side, and wherein the curvature radius gradually increases from the tongue portion to the starting position in at least a portion of the apex. ### Claim 14 (depends on 13) The scroll structure of a centrifugal compressor according to claim 13 wherein a flow passage shape of the scroll passage in a cross-section extending in a direction perpendicular to a centerline of the scroll passage is not circular in the cross-section including the tongue portion, wherein a flow passage shape of the outlet passage in a cross-section extending in a direction perpendicular to a centerline of the outlet passage approaches circular as the outlet passage extends downstream from a connecting position with the scroll passage, and wherein a position where the flow passage shape of the outlet passage changes from a non-circular shape to a circular shape is downstream of the outlet passage from the connecting position by a distance equal to or greater than a passage height at the winding end portion along an axial direction of the centrifugal compressor. ### Claim 15 (depends on 13) A centrifugal compressor, comprising the scroll structure of a centrifugal compressor according to claim 13.