Patent Application
20250116194
The present disclosure relates generally to radial turbines, and more specifically to radial turbine rotors.
Radial turbine rotors are characterized by rotating in response to a flow of working fluid radially inwardly toward the axis of rotation. In many applications, radial turbine rotors can be more efficient than axial turbine rotors that rotate in response to a flow of working fluid primarily parallel to the axis of rotation.
To increase efficiency of radial turbine rotors, it can be beneficial to increase the temperature of the working fluid that interacts with the rotors. However, manufacturing radial turbine rotors from high temperature materials and/or incorporating an active supply of cooling air into radial turbines presents challenges.
The present disclosure may comprise one or more of the following features and combinations thereof in an effort to address challenges in radial turbine rotor design and manufacture.
A radial turbine rotor may comprise a hub, a plurality of turbine blades, and an axial retainer. The hub may be arranged around a central axis and may be formed to include an annular shaft portion, a forward flange, and an aft flange. The annular shaft portion, the forward flange, and aft flange of the hub can be shaped to define a dovetail shape channel when viewed circumferentially around the axis. The turbine blades can be made from ceramic matrix composite materials. Each of the plurality of turbine blades can be shaped to include a dovetail root arranged in the dovetail shape channel of the hub and an airfoil that extends radially-outwardly for interaction with hot gasses that flow over the radial turbine rotor during use.
In illustrative embodiments, the aft flange is shaped to include an assembly gap that extends axially into the dovetail shape channel. The assembly gap can be sized to accommodate insertion of a single dovetail root into the dovetail shape channel during assembly of the rotor.
In illustrative embodiments, the retainer is mounted along an aft face of the aft flange to block undesired withdrawal of the turbine blades from the dovetail shape channel. The retainer can include a retention ring and a shaft. The ring can include an annular washer portion and a filler tab that extends from the annular washer portion into the assembly gap of the aft flange. The shaft may be engaged with radially-inwardly facing surfaces of both the hub and the retention ring to couple the turbine rotor components together for rotation about the axis.
In illustrative embodiments, each of the plurality of turbine blades is further formed to include a platform. The platform can extend circumferentially between airfoils of adjacent turbine blades to shield the hub radially inward of the platform. Optionally, the platform can extend aft and radially outward of the aft flange to shield the aft flange of the hub radially inward of the platform.
These and other features of the present disclosure will become more apparent from the following description of the illustrative embodiments.
For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to a number of illustrative embodiments shown in the drawings and specific language will be used to describe the same.
A radial turbine rotor 10 of the present disclosure is configured to extract energy from a working fluid, such as hot, high pressure combustion products, flowing through a gas path 18. The radial turbine rotor 10 rotates about a central axis 11 to extract mechanical work from the flow of working fluid to drive other components of the gas turbine engine. The flow of working fluid in the radial turbine rotor 10 may be, at least in majority part, radial to the central axis 11.
The radial turbine rotor 10 for use in a gas turbine engine includes a hub 12 made of metallic materials, turbine blades 14 made of ceramic matrix composite materials (CMCs), and a retainer 16. The retainer 16 facilitates coupling of the CMC turbine blades 14 to metallic the hub 12 as shown in
The hub 12 is shaped to have a generally diminishing diameter from a forward end 12F to an aft end 12A as shown in
In the illustrative embodiment, the hub 12 includes an annular shaft portion 20, a forward flange 22, and an aft flange 24 as shown in
The diameter of the aft flange 24 is smaller than the diameter of the forward flange 22 as shown in
In some embodiments, the hub 12 comprises nickel superalloy, such as, but not limited to, Udimet 720. In some embodiments, the hub 12 comprises nickel powder alloy, such as, but not limited to, RR1000. In some embodiments, the hub 12 comprises polycrystalline nickel-based superalloy, such as, but not limited to, Mar-M-247. In the illustrative embodiment, the hub 12 is integrally formed (cast/forged/machined) as a single component.
The turbine blades 14 are able to withstand relatively high temperatures on account of the CMC material used to create the blades 14. In the illustrative embodiment, the blades 14 comprise silicon-carbide fibers in a silicon-carbide matrix (SiC—SiC). The turbine blades 14 are coupled to the hub 12 via a dovetail coupling.
Each of the plurality of turbine blades 14 is shaped to include a dovetail root 26 and an airfoil 28 as shown in
Each of the plurality of turbine blades 14 can be formed to include a platform 30 as shown in
The retainer 16 is illustratively mounted along an aft face of the aft flange 24 to block undesired withdrawal of the turbine blades 14 from the dovetail shape channel 13 as shown in
While the disclosure has been illustrated and described in detail in the foregoing drawings and description, the same is to be considered as exemplary and not restrictive in character, it being understood that only illustrative embodiments thereof have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.
