Curved tooth coupling for a miniature gas turbine engine

A rotor assembly for a miniature gas turbine propulsion system, the rotor assembly comprising:

• a radial flow compressor wheel comprising:
• a first central bore;
• and
• a first coupling face including a first axially extending coupling face flange extending from an aft end of the compressor wheel;
• a radial flow turbine wheel comprising:
• a second coupling face including a second axially extending coupling face flange extending from a forward end of the turbine wheel, the second coupling face interconnected with the first coupling face by a set of concave-shaped teeth intermeshed with a set of convex-shaped teeth;
• a shaft extending from the first central bore of the radial flow compressor wheel;
• a tie bolt extending from the shaft to the turbine wheel through the first central bore;
• and
• a threaded fastener connected to the tie bolt to bring the first coupling face into contact with the second coupling face;
• wherein the first and second coupling face flanges include stress relief profiled radii disposed at a base of each flange.

A rotor assembly having an overall axial length of about fourteen inches (˜35.56 cm) or less and disposed in a miniature gas turbine propulsion system, the rotor assembly comprising:

• a compressor wheel comprising;
• a first curved outer diameter having a plurality of integrated blades;
• a first inner diameter bore extending through the compressor wheel;
• a counterbore positioned forward of the first inner diameter bore to form a shoulder;
• an axially extending aft end flange extending from the compressor wheel;
• and
• a downstream mate face on the aft end flange and having first toothed coupling members;
• a turbine wheel comprising:
• a second curved outer diameter having a plurality of integrated blades;
• a second inner diameter bore within the turbine wheel;
• an axially extending forward end flange extending from the turbine wheel;
• and
• an upstream mate face on the forward end flange and having second toothed coupling members configured for meshing with the first toothed coupling members;
• and
• a shaft comprising:
• a first shaft section extending in a forward direction from the counterbore of the compressor wheel such that an aft end of the first shaft section abuts the shoulder;
• and
• a tie bolt extending from an aft end of the first shaft section, through the first inner diameter bore and the second inner diameter bore, and connected to the turbine wheel to retain the compressor wheel between the shoulder and the turbine wheel;
• wherein the axially extending forward and aft flanges include stress relief profiled radii disposed at a base of each flange.

The rotor assembly having an overall axial length of about fourteen inches (˜35.56 cm) or less and disposed in a miniature gas turbine propulsion system, the rotor assembly comprising:

• a compressor wheel comprising;
• a first curved outer diameter having a plurality of integrated blades;
• a first inner diameter bore extending through the compressor wheel;
• a counterbore positioned forward of the first inner diameter bore to form a shoulder;
• an axially extending aft end flange extending from the compressor wheel;
• and
• a downstream mate face on the aft end flange and having first toothed coupling members;
• a turbine wheel comprising:
• a second curved outer diameter having a plurality of integrated blades;
• an axially extending forward end flange extending from the turbine wheel;
• and
• an upstream mate face on the forward end flange and having second toothed coupling members configured for meshing with the first toothed coupling members;
• and
• a shaft comprising:
• a first shaft section extending in a forward direction from the counterbore of the compressor wheel such that an aft end of the first shaft section abuts the shoulder;
• a second inner diameter bore within the shaft;
• and
• a tie bolt extending from a forward end of the turbine wheel through the first inner diameter bore and the second inner diameter bore, and connected to the turbine wheel to retain the compressor wheel between the shoulder and the turbine wheel;
• wherein the axially extending forward and aft flanges include stress relief profiled radii disposed at a base of each flange.