Claims
- 1. A high temperature turbine engine comprising a housing and a hybrid ceramic/metallic rotor member cooperatively defining an inlet, an outlet, and a flow path communicating a flow stream of elastic fluid therebetween, in response to rotation of said rotor member a compressor section inducting ambient air via said inlet and delivering this air pressurized to a combustor section, means delivering a supply of fuel to said pressurized air in said combustor section to support combustion producing a flow downstream in said flow path of high temperature pressurized combustion products, a turbine section expanding said flow of combustion products to extract mechanical power therefrom rotating said rotor member, said rotor member including a ceramic turbine portion having a ceramic hub part and a plurality of aeroreactive blades extending radially outwardly thereon, an integral ceramic boss part extending axially from said hub part, said boss part defining an axially extending first central bore opening on an end thereof and having an outer smaller diameter bore portion cooperating with the remainder thereof to define a step disposed away from said opening, an axially next-adjacent metallic rotor member portion confronting said boss part and defining an axially extending second bore aligning with said first bore, said turbine rotor portion and said axially next-adjacent portion including cooperating means for torque transmission and material coaxial radial alignment thereof dependent upon retention of a selected axial relationship thereof, a metallic annular collet member received axially into said first bore, said collet member including an annular ring portion and a circumferentially arrayed plurality of axially extending radially resilient finger portions extending from said ring portion to terminate at respective distal ends, said plurality of finger portions cooperatively defining a radially outwardly extending shoulder proximate said distal ends and engaging said step to retain said collet member in said first bore, an elongate tie bolt member threadably engaging said ring portion and being received in said second bore to apply an axially directed tensile force to said collet member which tensile force is reacted through said axially next-adjacent portion to retain the latter in said selected axial relationship with said first ceramic turbine portion.
- 2. The invention of claim 1 wherein said axially extending ceramic boss part further defines a circularly cylindrical axially elongate outer surface on said turbine rotor portion, said boss part outer surface defining a journal bearing surface for said turbine rotor.
- 3. The invention of claim 1 wherein said cooperating means includes said axially extending boss part carrying a metallic collar member securing thereto adjacent said end thereof, said collar member defining a first circumferentially arrayed plurality of curvic coupling teeth, said axially next-adjacent metallic portion defining a second circumferentially arrayed plurality of curvic coupling teeth meshing with said first plurality.
- 4. The invention of claim 3 wherein said collar member includes an axially extending annular band portion cooperating with the remainder of said collar member to define an axially extending recess, said axially extending boss part of said ceramic turbine rotor portion being received into said recess to define an interference fit relationship with said band portion.
- 5. The invention of claim 1 wherein a sleeve-like locking member is received axially into said collet member and is radially engageable by said plurality of finger portions to prevent disengagement of the latter from said step.
- 6. The invention of claim 5 further including said plurality of finger members collectively defining a radially inwardly extending second step proximate said distal finger ends, said second step being engageable by said sleeve-like locking member to prevent axial movement thereof in one axial direction.
- 7. The invention of claim 6 wherein said tie bolt member defines an abutment surface spaced from and confronting said second step, said abutment surface being engageable by back locking sleeve member to prevent axial movement thereof in a second direction opposite said first direction to thereby trap said sleeve member within said collet member.
- 8. A method of providing a hybrid ceramic/metallic rotor member for a high temperature turbine engine, said method comprising the steps of:
- providing a ceramic rotor member first portion:
- defining on said ceramic portion an integral axially extending boss part which in part defines an elongate axially extending bore opening on an end of said boss part;
- providing a metallic rotor member second portion axially next-adjacent to said first portion;
- coupling said first portion and said second portion for torque transmission therebetween and for retention of radially coaxial corotational relation dependent upon retention of a selected axial relationship therebetween:
- providing on said first portion bore an outer smaller diameter bore portion cooperating with the remainder of said bore to define a step disposed away from said bore opening:
- providing a metallic axially elongate collet member including an annular ring portion having an outer diameter slidably receivable axially into said smaller diameter bore portion, and a circumferentially arrayed plurality of elongate radially resilient finger portions extending axially from said ring portion to terminate in respective distal ends thereof:
- defining collectively on said plurality of finger portions and proximate said distal finger ends thereof a radially outwardly extending annular shoulder having an outer diameter greater than said smaller diameter bore portion:
- resiliently deflecting said plurality of finger portions radially inwardly at said distal ends thereof to reduce said shoulder to a diameter passable through said smaller diameter bore portion,
- passing said collet member axially into said bore to engage said shoulder with said step,
- applying an axially directed tensile force to said collet member directed to withdrawing the latter from said bore, and
- reacting said withdrawing force through said rotor member second portion to retain the latter and said first portion in said selected axial relationship.
- 9. The method of claim 8 wherein said step of coupling said first portion and said second portion includes the steps of:
- providing on said second portion a circumferentially arrayed first plurality of axially and radially extending curvic coupling teeth:
- providing a metallic collar member:
- permanently securing said collar member to said first portion at said boss part:
- providing on said collar member a circumferentially arrayed second plurality of curvic coupling teeth, and
- meshing said first plurality of teeth with said second plurality of teeth.
- 10. The method of claim 8 wherein said step of applying an axially directed tensile force to said collet member includes the steps of:
- defining a thread surface on said ring portion of said collet member,
- providing an elongate tie bolt member having an end termination part threadably engageable with said collet member,
- threadably engaging said collet member with said tie bolt; and
- applying a tensile force to said tie bolt member.
- 11. The method of claim 8 further including the steps of:
- providing a sleeve-like locking member,
- inserting said locking member into said collet member, and
- engaging radially said locking member with said plurality of finger members to prevent disengagement of the latter from said step.
Government Interests
The United States Government has rights in the present invention pursuant to Contract No. DEN3-167 issued and funded by the Department of Energy (DOE), and administered by the National Aeronautics and Space Administration (NASA).
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Foreign Referenced Citations (5)
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DE2 |
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578533 |
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2034440 |
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Entry |
Ceramic Design Methodology and the AGT101 Tech. Paper 3/1985 by Gary L. Boyd et al. |
Automotive Gas Turbine Ceramic Component Testing Tech. Paper by Carruthers et al. |