US2831320A - External turbine jet engine - Google Patents

Description

w. E. DUNCAN EXTERNAL TURBINE JET ENGINE April 22, 1958 Filed Oct. 9, 1953 Sheets-Sheet 1 April 22, 1958 w. E. DUNCAN EXTERNAL TURBINE JET ENGINE 3 Sheets-Sheet 2 Filed Oct. 9. 1953 April 22, 1958 w. E. DUNCAN r EXTERNAL TURBINE JET ENGINE 3 Sheets-Sheet 3 All Filed Oct. 9, 1953 4 WT W W United States Patent EXTERNAL TURBINE JET ENGINE Ward E. Duncan, Miami, Fla.

Application October 9, 1953, Serial No. 385,305

3 Claims. (Cl. 6035.6)

(Granted under Title 35, U. S. Code (1952), sec. 266) .The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention is directed in application to a new and improved jet engine having a rotating casing and presenting a highly simplified construction with a resulting economy of production. The engine in its practical form utilizes a rotating outer shell having connected therewith the rotor blades of the compressor section of the engine, the shell being also connected to a nozzle discharge wheel or turbine which is integral with the casing and which is rotated by jet discharge to drive the compressor rotor providing a compact efiicient engine structure with a minimum of parts as compared to jet engines now being utilized. This type of structure presented by the invention, moreover, reduces the maintenance problems consequent in the use of present jet engines. The improved engine also reduces the problem of controlling the engine temperature, the nozzle discharge wheel being in effect the turbine wheel which as arranged is exposed to additional air flow with a consequent reduction in operating temperature permitting a higher R. P. M. to be obtained within a desirable temperature range.

An object of this invention is to provide a new and improved rotary jet engine.

A further object of the invention is to provide an improved jet engine with a rotatable outer casing driven by jet discharge whereby the R. P. M. is controlled by the discharge.

Another object of the invention is to provide a highly simplified jet engine wherein the turbine wheel serves as a discharge nozzle wheel enabling greater engine efficiency.

An additional object of the invention is to provide an improved rotary jet engine incorporating variable area jet discharge nozzles.

Another object of the invention is to provide an improved rotary jet engine having a rotatable outer casing incorporating the rotor blades of the compressor section which casing is driven by jet discharge.

A further object of the invention is to provide an improved rotary jet engine that can operate at higher gas temperatures than prior jet engines.

Other objects and advantages of the invention will become readily apparent to those versed in the art from the following description taken in conjunction with the accompanying drawings wherein:

Fig. 1 shows a cross-section of the preferred form of the invention;

Figs. 2 and 3 present modifications of the preferred form of the invention;

Fig. 4 shows how the modification of Fig. 3 of the drawings may be incorporated in a fuel tank suspended from an air-craft; and

Fig. 5 is an end view of the engine of Fig. l disclosing details of the end wall and nozzle openings.

2,831,320 Patented Apr. 22,

' and extending longitudinally therefrom constitutes a fixed of the radial passages 19 in the end wall 18. These suitable fashion.

support for the stator blades 3 of the compressor section of the engine. A tall support section 4 of the engine-is bolted to the section 2 and forms a continuation thereof, being conical in longitudinal cross-section and forming a bearing at its rear. The compressor section of the engine is formed to have several stages. The first stage is in the form of a wheelwith rotor blades 5 and rotatable on a bearing 6 mounted on the adapter 1. The outer extremities of the first stage rotor blades are bolted to the engine outer casing 7 which is arranged for rotation relative to the fixed engine support. The rotor blades 5 of the successive stages of the compressor section are fixed to the outer casing of the engine and extend inwardly intermediate the stator blades. A plate 8 separates the compressor fixed section 2 and the tail support section 4. A starter unit 9 is bolted to the compressor side of the plate and has a drive shaft 10 extending therethrough to which is fixed a drive gear 11. Connected integrally to the plate on the tail side is a support 12 and the drive shaft is journalled in a bearing 13 fixed in the support. A tubular section 14 extends axially and centrally from the plate in a rearward direction. The rear end of the tubular section 14 is journalled in a bearing 15 in the support 12. A gear 16 integral with the tubular section adjacent the plate meshes with the gear 11 on the drive shaft. A tubular shaft 17 concentric with the tubular section 14 is fixed thereto in any suitable manner and extends rearwardly and axially through the tail section support 4 to a circular plate 17 extending transversely thereof and integral therewith at the rear end of the shaft. Bolted to the plate 17' is a nozzle wheel turbine or circular end wall 18 having a plurality of fluid guiding passages spaced uniformly along the periphery of the end wall 18 and having at least two radial passages or spokes 19 with each communicating with one of the peripheral passages 100. It will be understood that the number of passages 19 may be increased, if desired.

A bearing tube 20 for the tubular shaft 17 is fixed in the end opening of the tail section support 4 and extends rearwardly therefrom. Bearings are maintained between the end wall 18 and 'the tail support section 4 in any A scavenging line (not shown). is provided leading into the housing formed by the nozzle wheel turbine hub and enclosure 21 to provide lubrication for the nozzle wheel bearings.

Secured to the compressor side of the plate 8 axially and centrally thereof is a cylinder 22 to the front end of which leads a line 23 delivering hydraulic fluid from a supply. Mounted for movement in the cylinder 22 is a piston 24 having an elongated stem or rod 24' extending rearwardly through the tubular shaft 17 and beyond the- Fixed to the circular plate 17' each lever having its inner arm connected to the end of the piston rod 24'. The outer arm of each lever is pivotally connected to the inner end of a rod 28 (two' shown). Each of the rods 28 is slidably mounted in 'one along ;the periphery of the .end walh; Each; of-.the..outerends 29 of;the..:roc l s..28:;is shaped to cooperatewith an outer wnll-of cne.of-the.endwall passages. liltlto forma-conv.ergent-divergent nozzle. Exceptwherethe outer. ends-,29-1ofthe;v rods..28 extend; therefrom, the end wall 18.:hasaan.abutment portion secured thereto and shaped, simi-lar:to..-the= outer end 29 of the rod 28, to cooperate withoutenwalls 30'of;the.remaining. passages 100 to form convergent-divergent nozzles. Radial plates or vanes 101 form-the nozzle wallsiand fixthe nozzles. at anangle to :the :hotgastchamber sothe deflection of the gas by the..vanes imparts-arotational.motion .to the casing '7.- Theservanes 101, which. are secured to the end wall 18 and :themuter casing :7," extend beyond the end Wall farv enough. (see-Fig. 1) so that the heat imparted to. them by-the exhaustgas stream is dissipated into the outer air to.-.enable the end wall 18 to Withstand high operating temperatures. and resulting. in. greater engine efiiciency.

Asis' apparent, by control of the hydraulic fluid to the cylinder. 22; thepiston rod 24' can move longitudinally of the. tubular shaft 17 to control the bell crank levers 27 to-rnove the-rods 28 including theouter ends 29, which form the innerwalls of some of the nozzles 100, radially touniformly vary the cross sectional area of these nozzles. Itwill beunderstood that the remainder. of the nozzle 100 do not have a varying area since they do not have outenends 29=of the rods 28 disposed therein but have. the abutment portions. as previously set forth. However, all. of therpassages 100 could have'varying areasthrough 1671156: of outer ends 29 of the rods 28 extendingthereintoand forming an inner wall thereof, if desired. An annular combustion. chamber 31 adjacent the end wall 18zis positionedto discharge the hot exhaust gas stream againstthe periphery of the end wall 18 and through the fluid: guiding passages 100. The combustion chamber 311has-fuel injectors-.32 at the forwardend thereof to which, is led an appropriate fuel mixture. The outer Wall .of' the annular combustion chamber has openings therein. forcompressed air to enter from the diffuser passage33'following the compressor section. An igniter 3.4.extends into the chamber to ignite the air fuel mixture. Brace plates 35 extend between-the combustion chamber and the-tail support section.

In=additionan auxiliary accessory drive shaft 36 is connected by a universal joint to a shaft 37 extending through the plate, to which shaft is fixed a gear meshing with the tubular section gear for driving purposes. The otherend of the. shaft bears in a bearing 13 secured in the-support.

To start the engine, the starter is. energized torotate the-drive shaft17 and-.connected-nozzle wheel to which is.--securedi the outer. engine casing by its. connection to the.;-outernozzle walls to drive the casewith its con nected compressor vanes inducing an axial air flow which is compressed through the variousstages of the compressor. and flows intothe air diffuser passagewhere there is a-further pressure. increase. The air then enters the combustionchamber through the openings in the outer wall thereof whereit ismixed with fuel from the fuel injectors. The mixture is then ignited and discharged through the nozzles which have the cross-secti'onal' areas properly. adjusted, The air flow being slightly deflected by the nozzleyanes causes the engine casing to rotate, as well as providing a forward thrust.

The rqtatio'n .of the engine-casing drives the compressor sotheenergy withdrawnfromthe exhaust gas stream to, producethe rotationaLmotion is substantially returned to the ys em Aften-combustion hasstarted, the igniter may be turned ofic sinceincomingfuel: ain mixtureis. ignited by; the.

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process.

The cross-sectional area of the nozzles is increased by pumping hydraulic fluid into the cylinder 22 while the decrease in cross-sectional area is accomplished by bleeding fluid from the cylinder and centrifugal force moves the inner walls of the nozzles outwardly.

This construction provides high efiiciency with fewer moving parts and lighter weight than contemporary jet engines. It also eliminatestheconventional nozzle diaphragm and the conventional arrangement of the turbine wheel with its accompanying temperature control problems. The particular nozzle control arrangement provides also immediate and positive control of engine output.

A modification of the invention, shown in Fig. 2 of the drawings, consists of a support shaft 41 hollow in natureand having spaced bearings..42;and 43 thereon. Mountedon thefirstlbearing 42 is a compressorl4'4 of the centrifugal flow type. The rotor is. fixed against movement longitudinally of the hearing by a circular plate 45 bolted theretohaving gear teethabout itsperiphcry and a central aperture with a flangethereabout abutting the bearing 42. A radial support 46 for the air .difiuser assembly 47-mounted on shaft 41 also serves" to have a bearing seal 48- secured thereto. A second support 49. mounted on the shaft 41 abuttingthehub of the first support has a radial transverse plate. 49 integral therewith andspaced rearwardly of 'the first sup.- port. Braced support elements 50 connect the supports 46 and 49 and therewith serve to mount the annular.

diffuser element. Mounted on the rear end of the s'i1p port shaft 41 is a nozzlewheel or circular end wall '51 having a plurality of'passages 200. mounted on bearings 43. A housing 52 secured to the n'ozz le wheel pro.- vides a tail cone. A combustion chamber53annular in form is supported. by the bracestructureand an igniter 54 extends through the wall thereof at a position spaced fromthe fuel injector 55. connected thereto. The'stationary hollow shaft 41 serves to house the fuel and oil lines extending to the fuel injector and front and rear bearings respectively. The'engine outer casing 56 is connected to the outer periphery of thenozzle wheel and to the compressor. I

A motor M is used forstarting. It may be incorporated in any suitable manner as in the stationary portion and geared to the compressor, for example, as shown in Fig. 20f the drawings.

In this modification air is compressed and accelerated bythe compressor vanes, flowing through the radial passages and leaving in a spiral path, then entering the diffuser section 47 of a spiral type with diverging passages, raising the air pressure. The. air passes then through openings in the combustion chamber where it.

The discharge of the is mixed with fuel and ignited. products of combustion" through the nozzles which are of the convergent-divergenttype and angled as in the preferred modification described herein produces the rota tional as well as forward thrust. The nozzle wheel or end wall of this modification disclosed in Fig. 20f the drawing, of the invention may utilize the fixed convergentdivergent type nozzle or may utilize the variable area type as in the preferred form of the invention. The manner of inclusion of the hydraulic control through. hollow shaft 41 to the nozzle wheel being obvious and repetitious is unnecessary. The principles employed. in this modification, as in the first, involve the connection of the nozzle Wheel to the outer casing of the engine which is connected to the compressor to drive the compressor providing a simple, economical, efficient engine.

A second-modification, see Fig. 3, of the invention comprisesa hollow shaft 61- rotatably supported. Connected to the shaft for rotation therewith is a centrifugal compressor. unit 62 connected to the outer casing 68. At the rear of the.casingandaconnected to the shaft 61 is a nozzle wheel or end wall 63 having a plurality of passages 300 defining nozzles 64. The nozzles extend rearwardly and are inclined away from the direction of rotation of the wheel. The nozzle wheel is connected to the casing 68 in any suitable manner for rotation therewith. A tail cone 68 is fixed to the nozzle wheel. An annular combustion chamber 65 within the outer casing has fuel lines 66 leading thereto from the hollow shaft 61 for fuel injection. Igniters 67 also extend into the combustion chamber to ignite the fuel introduced into the chamber. Openings in the combustion chamber admit air from the compressor unit for mixture with the fuel and ignition. The ejection of the products of combustion through the nozzles produces forward thrust as well as the rotational force necessary to rotate the outer casing to drive the compressor. Here also the variable area convergent-divergent nozzles may be employed in a manner as shown in the preferred embodiment of the invention. Fig. 4 shows how the modification of Fig. 3 may be employed in a pod suspended from an aircraft.

As can be readily seen, the principles employed in the various modifications of the invention are simple in nature and lend themselves to many variations and applications which may readily be contemplated by those versed in the art and such is within the scope of the invention.

What is claimed is:

1. An engine comprising a stationary support, a casing rotatably mounted on the support, said casing integral with an end wall, said end wall having a plurality of spaced fluid guiding passages disposed closely adja cent the end wall periphery, fluid accelerating means in the engine positioned to direct a fluid stream against the periphery of the end wall and through the fluid guiding passages, said fluid guiding passages interacting with the fluid stream to impart rotational energy to the casing, means connected to the engine for simultaneously and uniformly varying the cross sectional area of at least two of the passages in the end wall.

2. The invention set forth in claim 1 wherein the means for simultaneously and uniformly varying the cross sectional area of at least two of the passages on the periphery of the end wall includes at least two passages in the end wall which radiate from a common point, an elongated element slidably mounted in each of the radiating passages, one end of each of said elongated elements positioned in one of said passages on the periphcry of the end wall and shaped to cooperate with the outer peripheral surface of these passages to form adjustable convergent divergent nozzles, and means connected to said elongated elements for actuating them to simultaneously and uniformly vary the cross sectional area of at least two of the convergent divergent nozzles.

3. The invention set forth in claim 2 wherein the means for simultaneously and uniformly actuating the elongated elements includes an actuating shaft extending along the axis of the casing and means connecting the actuating shaft to the slidable elongated elements.

References Cited in the file of this patent UNITED STATES PATENTS 2,410,533 Walton Nov. 5, 1946 2,641,105 Drake June 9, 1953 2,679,725 Sharma June 1, 1954 FOREIGN PATENTS 587,528 Great Britain Apr. 29, 1947

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