Turbine wheel containment shroud for a pneumatically powered turbine engine starter motor

• US 4,044,550 A
• Filed: 09/10/1975
• Issued: 08/30/1977
• Est. Priority Date: 09/10/1975
• Status: Expired due to Term

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Vermilye, Michael Lee
• Primary Examiner(s): Croyle, Carlton R.
• Assistant Examiner(s): Casaregola, L. J.
• Application Number:
  US05/612,205
• Time in Patent Office: 720 Days
• Field of Search: 60/39.09 R, 60/39.14, 60/39.5, 60/39.09 P, 415/9, 415/205, 416/247, 74/609
• US Class Current: 60/39.091
• CPC Class Codes: F01D 21/045 special arrangements in stators or in rotors dealing with breaking-off of part of rotor

Abstract

A containment shroud is attached to the exhaust outlet of a pneumatically powered turbine engine starter for containing the turbine wheel should it be inadvertently disengaged and expelled from the starter motor. The shroud includes a radially flared annularly shaped member attached to and extending outwardly or rearwardly from the exhaust outlet of the motor. A relatively massive central cylindrical member or button is positioned within the annularly shaped member adjacent the outer opening of the annularly shaped member. Four circumferentially spaced, radially outwardly extending bars tie the button to the annularly shaped member and position it adjacent the outer opening of the annularly shaped member. Should the turbine wheel dislodge from the starter motor, it will exit through the starter exhaust opening into the annular member and contact the button and inner surface of the annular member. As it does so, the rotational energy of the wheel will be dissipated via the scrubbing action of the wheel on the button, the bars and the inner surface of the annular member. When the wheel is expelled into the annular member, it will tend to block the outer opening of the annular member. Therefore, a plurality of spaced circumferential openings are located in the annular member adjacent its connection point to the starter exhaust outlet to relieve fluid pressure in a radially outward direction from within the motor if the wheel blocks the opening.

Claims

1. A containment shroud for affixation to the exhaust duct of a fluid powered starter motor for a turbine engine, said exhaust duct including an exhaust outlet having an axis and a generally circular opening oriented transversely to said axis, said motor having a turbine wheel mounted within said motor for rotation about an axis substantially coaxial with the axis of said exhaust outlet, said shroud comprising:

an annularly shaped member, said member being adapted to be positioned adjacent to and to extend outwardly from the opening of said exhaust outlet, said member having an axis adapted to be oriented substantially coaxially with the axis of said exhaust outlet, said member having at least one aperture opening radially outwardly adjacent the opening of said exhaust outlet for relieveing fluid pressure from within said member and said exhaust outlet, the outer end of said member terminating in and defining an outer opening spaced outwardly from the opening of said exhaust outlet when said member is positioned adjacent said exhaust outlet, and

blocking means positioned within and fixed to said annularly shaped member adjacent said outer opening, said blocking means being so oriented and constructed as to permit substantial fluid flow through said outer opening and to prevent egress of said turbine wheel from said outer opening.

2. The containment shroud of claim 1 wherein said member has an inner opening adapted to be positioned adjacent the opening of said exhaust outlet, said inner opening being generally circular and corresponding in size to the opening of said exhaust outlet, and wherein said member is radially flared relative to its axis from said inner opening to said outer opening.

3. The containment shroud of claim 1 wherein said annularly shaped member is frustoconically shaped and wherein said outer opening has a diameter greater than the diameter of said inner opening.

4. The containment shroud of claim 1 wherein said annularly shaped member has a plurality of apertures opening radially outwardly through said annularly shaped member adjacent said inner opening, said plurality of openings being circumferentially spaced about said annularly shaped member.

5. The containment shroud of claim 1 wherein said blocking means comprises at least one bar extending transversely across the said annularly shaped member.

6. The containment shroud of claim 5 wherein said bar is located inwardly from and adjacent to said outer opening.

7. The containment shroud of claim 6 wherein said blocking means further comprises:

at least a second bar extending transversely across the interior of said annularly shaped member adjacent to and spaced inwardly from said outer opening, said second bar oriented transversely to said first bar, and

a massive central member mounted substantially coaxially relative to said annularly shaped member, said central member being affixed to said first and second bars at a central location within said annularly shaped member.

8. The containment shroud of claim 1 wherein said blocking means comprises a massive central member mounted substantially coaxially within said annularly shaped member adjacent to and spaced inwardly from the outer opening of said annularly shaped member, said central member having a transverse dimension less than the outer opening so as to permit egress of fluid through said outer opening, and

means for affixing said central member to said annularly shaped member.