Abstract:
A turbojet engine is made from a drum-like portion having a circular blade section extending inwardly therefrom, a support member, and a bearing arranged around a circle having a diameter substantially equal to or greater than the diameter of the blade section. The drum-like portion is rotatably mounted within the support member on the bearing. Instead of a turbine spinning on a shaft, a turbine spinning within a drum is employed.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to turbine engines and, in particular, to an engine having a rotating drum instead of a rotating shaft. 
     In order to improve the performance of turbine engines, particularly turbojet engines, it has been common to increase sizes, rotational speeds and/or operating temperatures. This has presented challenges to building reliable engines. Such changes, for example, place increased demands on bearings, turbine blades and discs. 
     An area of interest has been the increased use of ceramic and other high temperature composites in the high temperature portions of the engine. Unfortunately, using such materials under tension presents its own problems. For example, a simple notch in the material may cause a catastrophic failure. The invention described herein avoids notch sensitivity and other structural problems. 
     SUMMARY OF THE INVENTION 
     An engine includes a drum-like portion having a circular blade section extending inwardly therefrom, a support member; and a bearing arranged around a circle having a diameter substantially equal to or greater than the diameter of the blade section. The drum-like portion is rotatably mounted within the support member on the bearing. A drive fluid source provides a fluid to rotate said drum-like portion. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side cross sectional view through the center axis of an engine according to the invention. 
     FIG. 2 is a schematic view of a cross section through the line  2 — 2  of FIG.  1 . 
     FIG. 3 is a schematic view of a cross section through the line  3 — 3  of FIG.  1 . 
     FIG. 4 is a side cross sectional view through the center axis of another engine according to the invention with a schematically indicated non-turbine engine located within the turbine engine. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, an engine  10  includes a drum-like portion  12  with inwardly extending circular blade sections  14 . In the preferred embodiment, the blade sections  14  may be classified as belonging to a fan section  16 , a compressor section  18 , a high pressure section  20  or a low pressure section  22 . The portion  12  rotates on bearings  24 ,  26 ,  27 ,  28  surrounding the portion  12 . 
     In the preferred embodiment, the bearings  24 ,  26 ,  27 ,  28  are arranged about a circle having a diameter that is, for example, equal to or greater than that of one or more of the blade sections  14 . For example, the bearings  24 ,  26 ,  27 ,  28  may be a series of caged ball bearings  30  (see FIGS.  2  and  3 ). It is also possible for the bearings  24 ,  26 ,  27 ,  28  to be, for example, encircling roller bearings or the bearings may be formed from discrete bearings located at, for example, 120, 90, 60 or 45 degree intervals about the portion  12 . Thrust bearings  32 ,  34  are located at the ends of the portion  12  to contain the portion  12  longitudinally. 
     The bearings  24 ,  26 ,  27 ,  28 ,  32 ,  34  are mounted in a  30  support member  36  that generally surrounds the portion  12 . The support member  36  may be advantageously attached to an unshown object (e.g., an aircraft wing or fuselage) by means of pylons  38 ,  40 . 
     A hollow stationary member  42  may be advantageously attached to the support member  36  by pylons  44 ,  46 ,  48 ,  50  in a position coaxial with the portion  12 . Other unshown pylons may be spaced out the stationary member to further attach the stationary member  42  to the support member  36 . 
     The stationary member  42  may be advantageously provided with outwardly extending blade sections  52  which may also be classified as belonging to the fan section  16 , the compressor section  18 , the high pressure section  20  or the low pressure section  22 . 
     Combustors  54  may be advantageously provided ahead of the high pressure section  20 . The combustors  54  are supplied with a fuel by a fuel line  56 . 
     Once the drum-like portion  12  is spun up to a suitable speed by methods well known in the turbine art, air is drawn in to the inlet  58  by the fan section  16 . In the preferred embodiment, a portion of the air exiting the fan section  16  bypasses the remainder of the engine  10  by exiting through bypass outlets  60  between pylons  62 ,  64  that attach a forward portion  66  to an aft portion  68  of the drum-like portion  12 . Other unshown pylons may be spaced about the forward portion  66  to further attach the forward portion  66  to the aft portion  68 . 
     Another portion of the air exiting the fan section  16  enters the compressor section  18  where it is compressed. The air compressed in the compressor section  18  exits to mix with fuel from the combustors  54  and the mixture burns as it enters the high pressure section  20  followed by the low pressure section  22 . The hot expanding combustion gasses act upon the blade sections of the high pressure section  20  and the low pressure section  22  to rotate the portion  12  and, in the preferred embodiment, to provide thrust from the engine  10 . Air also passes through the hollow center of the stationary member  42 . 
     In the preferred embodiment, combustion gases provide a drive fluid to rotate the drum-like portion  12  and the blade sections  14 . In other embodiments of the invention, it may be desirable to employ other sources of drive fluid. 
     It should be noted that all rotating components of the engine  10  are in compression. This allow he use of ceramic and other high temperature composites in the high temperature portions of the engine without the constraints of operating such materials in tension. The problem of catastrophic burst discs in turbojets is eliminated along with the weight associated with shielding from such catastrophes. In addition, the large bearing surfaces minimize bearing lubrication requirements. 
     In general, the engine  10  has fewer parts than prior art engines and, particularly with the use of high temperature composites, weighs, for example, as much as fifty percent less for a given thrust rating. 
     Referring to FIG. 4, an additional embodiment of the engine  10 ′ includes not only the engine  10 , but also another thrust producing engine  70  located within the hollow portion of the stationary member  42 . The engine  70  may be, for example, a rocket engine, a ram-jet engine, or other thrust producing engine. It should also be noted that one or more additional coaxial drum-like portions can be used for the engine  70 . For example, a counter rotating drum can be mounted within the hollow portion of the stationary member  42  and operated in the same manner as the drum-like portion  12 . 
     It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited.