# US 4,392,778 A · Double flow reheat diaphragm > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,392,778 A - Document ID: US4392778A - Status: Granted - Kind: A - Application number: 06/249,894 - Filed: 1981-04-01 - Granted: 1983-07-12 - Earliest claimed: 1981-04-01 - Assignees: General Electric Company - Inventors: John M. Hess - Web page: https://patentgrep.com/patent/US4392778A ## CPC - F01D 25/246: {Fastening of diaphragms or stator-rings} - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) ## Abstract In a double flow section of a steam turbine, the inner web of the diaphragm surrounding the rotor shaft in the region of divergence of the steam flow paths, is fabricated in the form of two cylindrical shells which are held together either in a fixed position or in a relatively fixed position which permits some slight axial motion between the shells. This form of diaphragm eliminates a number of machining and fabrication alignment problems and additionally permits differential axial expansion of the two pieces occurring as a result of internal thermal steam conditions. ## Claims ### Claim 1 An inner web of a diaphragm for use in a double flow section of a steam turbine having a rotor shaft with a plurality of bucket wheels affixed thereto, said wheels rotate about the axis of said shaft between a plurality of stationary nozzle rings formed by curved partitions, said web comprising: a first cylindrical shell formed in two joinable halves for surrounding a portion of said rotor shaft, said first shell having at least two circular grooves along the inner periphery thereof for holding steam packing material in close proximity to said rotor shaft, said first shell also having a surface around the outer periphery of a first end thereof for attachment of curved partitions; a second cylindrical shell formed in two joinable halves for surrounding the second end of said first shell, said second end being displaced along said axis from said first end, and said second shell also having a surface around the outer periphery thereof for attachment of curved partitions; and means for holding said second shell in a relatively fixed position around said first shell but permitting limited axial movement between said first and said second shell. ### Claim 2 (depends on 1) The web of claim 1 in which said holding means comprises a rabbet joint between said first and second shells. ### Claim 3 (depends on 1) The web of claim 1 in which said holding means comprises a hook-fit joint between said first and second shells. ### Claim 4 (depends on 1) The web of claim 1 in which there is an aperture in said first shell between said at least two circular grooves. ### Claim 5 (depends on 1) The web of claim 1 in which said shell halves are joined by bolts. ### Claim 6 (depends on 1) The web of claim 1 further including thermocouples along the inner periphery of said first shell. ### Claim 7 (depends on 1) The web of claim 1 further including a plurality of curved partitions attached around the outer periphery of said shells to said surfaces for receiving said partitions. ### Claim 8 (depends on 7) The web and partitions of claim 7 further including outer rings attached to said curved partitions along the radially outward portions thereof. ### Claim 9 (depends on 1) The web of claim 1 in which said first and second shells are steel. ### Claim 10 An inner web of a diaphragm for use in a double flow section of a steam turbine having a rotor shaft with a plurality of bucket wheels affixed thereto, said wheels rotate about the axis of said shaft between a plurality of stationary nozzle rings formed by curved partitions, said web comprising: a first cylindrical shell formed in two joinable halves for surrounding a portion of said rotor shaft, said first shell having at least two circular grooves along the inner periphery thereof for holding steam packing material in close proximity to said rotor shaft, said first shell also having a surface around the outer periphery of a first end thereof for attachment of curved partitions, and including a second end which is displaced along said axis from said first end; a second cylindrical shell formed in two joinable halves, said second shell also having a surface around the outer periphery thereof for attachment of curved partitions; and means for holding said second shell in a fixed position against the second end of said first shell. ### Claim 11 (depends on 10) The web of claim 10 in which said holding means comprises bolts. ### Claim 12 (depends on 11) The web of claim 11 in which said holding means, further includes a circumferential rabbet joint. ### Claim 13 An inner web of a diaphragm for use in a double flow section of a steam turbine having a rotor shaft with a plurality of bucket wheels affixed thereto, said wheels rotate about the axis of said shaft between a plurality of stationary nozzle rings formed by curved partitions, said web comprising: a first cylindrical shell formed in two joinable halves for surrounding a portion of said rotor shaft, said first shell having at least two circular grooves on the inner periphery thereof for holding steam packing material in close proximity to said rotor shaft, said first shell also having a surface surrounding the outer periphery of a first end thereof for attachment of curved partitions and including a second end which is axially displaced from said first end; a second cylindrical shell formed in two joinable halves for surrounding the second end of said first shell, said second shell also having a surface around the outer periphery thereof for attachment of curved partitions; and means for joining said second shell to said first shell, said joining means permitting limited axial movement between said first and said second shell. ### Claim 14 (depends on 13) The web of claim 13 in which said adjoining means comprises a rabbet joint between said first and second shells. ### Claim 15 (depends on 13) The web of claim 13 in which said joining means comprises a hook-fit joint between said first and second shells.