# US 11,905,852 B2 · Intermediate element for a blade/rotor disc connection in a rotor of a turbomachine, associated rotor for a turbomachine, and turbomachine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,905,852 B2 - Document ID: US11905852B2 - Status: Granted - Kind: B2 - Application number: 17/627,815 - Filed: 2020-07-14 - Published: 2022-08-25 - Granted: 2024-02-20 - Earliest claimed: 2019-07-19 - Assignees: MTU Aero Engines AG - Applicants: Mtu Aero Engines AG - Inventors: Martin Pernleitner; Klaus Wittig; Manfred Dopfer; Dieter Freno; Tino Hummel - Web page: https://patentgrep.com/patent/US11905852B2 ## CPC - F01D 5/3007: {of axial insertion type} - F01D 5/3092: {Protective layers between blade root and rotor disc surfaces, e.g. anti-friction layers (F01D5/288 takes precedence)} - F01D 5/323: {Locking of axial insertion type blades by means of a key or the like parallel to the axis of the rotor} - F04D 29/322: {Blade mountings} - F04D 29/34: Blade mountings {(for axial flow compressors F04D29/322)} - F05D 2230/54: by sheet metal manufacturing - F05D 2250/711: convex - F05D 2250/712: concave - Y02E 10/72: Wind turbines with rotation axis in wind direction - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - 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 - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract An intermediate element is for a blade/rotor disk connection in a rotor of a fluid flow machine. The intermediate element is adapted to a shape of a blade root of a blade and to a blade root slot in a rotor disk for receiving the blade root such that, when arranged between the blade root and rotor disk, the intermediate element prevents contact between the blade root and rotor disk. The intermediate element has, on an outer surface that faces the rotor disk, at least one protrusion to reduce an air flow parallel to an axis of rotation of the rotor between the rotor disk and the intermediate element; and on an inner surface that faces the blade root, a recess that corresponds to the at least one protrusion. ## Claims ### Claim 1 An intermediate element for a blade/rotor disk connection in a rotor of a fluid flow machine, the intermediate element being adapted to a shape of a blade root of a blade and to a blade root slot in a rotor disk for receiving the blade root in such a way that, when in a state arranged between the blade root and the rotor disk, the intermediate element prevents direct contact between the blade root and the rotor disk, the intermediate element comprising, on an outer surface that faces the rotor disk in the state arranged between the blade root and the rotor disk, at least one protrusion configured to reduce an air flow parallel to an axis of rotation of the rotor between the rotor disk and the intermediate element; and on an inner surface that faces the blade root in the state arranged between the blade root and the rotor disk, a recess that corresponds to the at least one protrusion on the outer surface of the intermediate element, wherein, in the arranged state, the at least one protrusion is arranged in a region of a non-load-bearing flank of the blade root. ### Claim 2 (depends on 1) The intermediate element according to claim 1, wherein the intermediate element is in the form of an anti-wear sheet, having an axial sectional contour that corresponds to an axial sectional contour of the blade root, which has a fir-tree profile. ### Claim 3 (depends on 1) The intermediate element according to claim 1, wherein, the intermediate element is configured such that, when in the arranged state, the intermediate element entirely surrounds the blade root at the surface thereof facing the blade root slot. ### Claim 4 (depends on 1) The intermediate element according to claim 1 wherein on the outer surface that faces the rotor disk in the state arranged between the blade root and the rotor disk, the intermediate element comprises a plurality of protrusions configured to reduce the air flow parallel to the axis of rotation of the rotor between the rotor disk and the intermediate element; and on the inner surface facing the blade root, a plurality of recesses that respectively each correspond to the respective protrusions, the plurality of protrusions comprising the at least one protrusion and the plurality of recesses comprising the recess. ### Claim 5 (depends on 4) The intermediate element according to claim 4, wherein in the state arranged between the blade root and the rotor disk, at least some of the plurality of protrusions are arranged next to one another in a sectional plane perpendicular to the axis of rotation of the rotor disk. ### Claim 6 (depends on 4) The intermediate element according to claim 4, wherein, in the state arranged between the blade root and the rotor disk, the plurality of protrusions are arranged at different heights along the axis of rotation of the rotor. ### Claim 7 (depends on 1) The intermediate element according to claim 1, wherein the at least one protrusion includes a plurality of protrusions, and wherein, in the arranged state, at least one of the plurality of protrusions is arranged in a region of a bottom of the blade root slot, and extends away from the blade root. ### Claim 8 (depends on 1) The intermediate element according to claim 1, wherein the at least one protrusion is in a shape of a flattened dome. ### Claim 9 (depends on 1) The intermediate element according to claim 1, wherein, in the state arranged between the blade root and the rotor disk, the at least one protrusion is of a rectangular shape in a sectional plane perpendicular to the axis of rotation of the rotor disk. ### Claim 10 (depends on 1) The intermediate element according to claim 1, wherein, in the state arranged between the blade root and the rotor disk, the at least one protrusion is arranged on an end of the intermediate element facing away from the axis of rotation of the rotor. ### Claim 11 (depends on 1) The intermediate element according to claim 1, wherein, in the state arranged between the blade root and the rotor disk, an axial securing sheet, configured to axially secure or radially preload the blade root, is arranged between an end of the intermediate element facing the axis of rotation of the rotor and the rotor disk. ### Claim 12 (depends on 1) The intermediate element according to claim 1, wherein the at least one protrusion is formed in a planar portion of the intermediate element. ### Claim 13 (depends on 12) The intermediate element according to claim 12 wherein the at least one protrusion runs over an entire width of the planar portion of the intermediate element, and wherein the width of the planar portion extends in a sectional plane that runs perpendicularly to the axis of rotation of the rotor disk. ### Claim 14 (depends on 1) The rotor for the fluid flow machine, wherein the rotor comprises the rotor disk and a multiplicity of blades, comprising the blade, fastened to the rotor disk, and wherein the intermediate element according to claim 1 is arranged between at least one blade root of the blade and the rotor disk in such a way that the blade root does not directly touch the rotor disk. ### Claim 15 (depends on 14) The fluid flow machine comprising the rotor according to claim 14. ### Claim 16 (depends on 1) The intermediate element according to claim 1, wherein the fluid flow machine is an engine. ### Claim 17 (depends on 1) The intermediate element according to claim 1, wherein the intermediate element is in the form of an anti-wear sheet, having an axial sectional contour that corresponds to an axial sectional contour of the blade root, which has a dovetail profile. ### Claim 18 (depends on 1) The intermediate element according to claim 1, wherein the intermediate element is in the form of an anti-wear sheet, having an axial sectional contour that corresponds to an axial sectional contour of the blade root, which has a hammerhead profile.