Ceramic turbine rotor disc and blade configuration

• US 3,897,171 A
• Filed: 06/25/1974
• Issued: 07/29/1975
• Est. Priority Date: 06/25/1974
• Status: Expired due to Term

• Current Assignee: William F. Stahl
• Original Assignee: William F. Stahl
• Inventors: Stahl, William F.
• Primary Examiner(s): Powell, Jr., Everette A.
• Application Number:
  US05/482,913
• Time in Patent Office: 399 Days
• Field of Search: 416/244A,213,193,241B
• US Class Current: 416/244.00R
• CPC Class Codes: F01D 5/22 Blade-to-blade connections, e.g. for damping vibrations
• CPC Class Codes: F01D 5/284 Selection of ceramic materials
• CPC Class Codes: F01D 5/30 Fixing blades to rotors; Blade roots ; Blade spacers

Abstract

A ceramic gas turbine rotor disc is formed integrally with an array of ceramic airfoil blades. Each blade has an elongated shank portion to reduce thermal and mechanical stresses on the rotor disc. An elongated cavity is disposed between adjacent shank members. Each elongated cavity is filled with undensified unattached silicon nitride plug. The plug acts as a centrifugal force pin, preventing excessive blade vibration. Each plug also helps reduce hot motive fluid leakage between adjacent blade shanks.

Claims

1. A ceramic rotor disc for gas turbines including:

ceramic airfoil blades integral with said ceramic rotor disc;

each of said airfoil blades having an airfoil portion on their radially outer section an intermediate platform portion, and an elongated shank portion on their radially inner section, an elongated cavity being disposed between adjacent blade shanks, each of said cavities having wall portions, said wall portions being coated with a parting material, said cavity being filled with a ceramic plug, said ceramic plug serving as a centrifugal force pin to help reduce vibratory motion of the airfoil blades during rotor disc rotation.

2. A ceramic rotor disc for a gas turbine as recited in claim 1, wherein the radially outermost opposing wall portions of said elongated cavity generally defines an acute angle with one another, and said ceramic plug is wedged therein due to ceNtrifugal forces generated during rotor disc rotation, each of said ceramic plugs wedged therein preventing leakage of hot motive fluid from the hot motive fluid flowpath to the blade shank area.

3. A ceramic rotor disc for a gas turbine as recited in claim 1, wherein said ceramic plug in said cavity comprises a silicon powder, disposed therein, said silicon powder disposed therein being reacted with nitrogen to form a silicon nitride plug.

4. A ceramic rotor disc for a gas turbine as recited in claim 3, wherein said silicon nitride plug is comprised of a generally porous material.