US3062498A - Turbine nozzle and rotor arrangement - Google Patents

Description

Nov. 6, 1962 P. T. ANGELL ETAL 3,062,498

TURBINE NOZZLE AND ROTOR ARRANGEMENT Original Filed May 4, 1954 v 3 SheetsSheet 1 Ezra IZZQTE Pierce T A1296! Faberzfl dljborn i Z r i Nov. 6, 1962 P. T. ANGELL ETAL 3,062,498

- TURBINE NOZZLE AND ROTOR ARRANGEMENT Original Filed May 4, 1954 3 Sheets-Sheet 2 ETLFEWZQITE B'erce T Anya/l Faber! U/ born Nov. 6, 1962 P. 1'. ANGELL ETAL 3,062,498

TURBINE NOZZLE AND ROTOR ARRANGEMENT Original Filed May 4, 1954 3 Sheets-Sheet 3 EYE TZZE TE Pierce T Ange/l Robert C/Zborzz b MM Z i 3,062,498 TURBINE NOZZLE AND ROTOR ARRANGEMENT Pierce T. Angeli, Pepper Pike Village, and Robert Cliborn, South Euclid, Ohio, assignors to Thompson Ramo Wooldridge Inc., Cleveland, Ohio, a corporation of Ohio Original application May 4, 1954, Ser. No. 427,599, new Patent No. 2,910,005, dated Oct. 27, 1959. Divided and this application Dec. 11, 1958, Ser. No. 779,592 3 Claims. (Cl. 253-78) The present invention relates to apparatus for pumping liquids or the like by power developed from a source of expandable fluid. More particularly, the invention relates to the provision in such apparatus of a new and improved turbine nozzle and vane construction.

This application i a division of our co-pending application, Serial No. 427,599, which was filed May 4, 1954 and issued into Patent No. 2,910,005 on October 27, 1959.

The problem of providing simple turbine constructions for use in such modern fields as aviation and like arts has been a serious one. In such uses, the turbine must be extremely strong with a minimum of weight and a -maximum of fluid flow per inch of diameter of the tur- .bine rotor.

These requirements are extremely important in the eflicient design of modern light weight equipment and have been considered absolutely necessary in order to utilize the compressed gases available for a power source on modern jet aircraft, for example.

By the present invention, a simplified and substantially improved turbine rotor structure has been provided while retaining an extremely small turbine rotor diameter and while maintaining the cost of manufacture at a minimum. In reducing the cost of the present turbine apparatus, applicants have simultaneously achieved substantially greater strength thereby permitting high operating speeds with a minimum of operational break downs.

It is, therefore, an object of the present invention to provide a simplified turbine nozzle and rotor construction.

Another object is to provide a method of manufacturing turbine nozzle passages in a simplified manner.

Another object of the present invention is to provide a turbine having a large ratio of flow area per inch of turbine rotor diameter.

A further object of the present invention is to provide a nozzle and rotor combination in which an inlet nozzle plate extends axially within a housing and is provided with vanes extending radially from a hub into substantial contact with the housing, and in which a turbine rotor is mounted in the housing adjacent the nozzle plate and is provided with vanes extending radially into substantial contact with the housing whereby there is provided a con tinuous flow controlling path'through said housing.

Still other and further objects and features of the present invention will become apparent to those skilled in the art from the consideration of the attached sheets of drawings wherein:

FIGURE 1 is an elevational view in cross section of a preferred form of turbine and pump construction;

FIGURE 2 is an end elevational view of the structure shown in FIGURE 1;

FIGURE 3 is a cross-sectional view taken along the line III-III of FIGURE 1;

FIGURE 4 is a partial elevatio-nal view in cross-section showing a modified form of turbine nozzle and taken along the line similar to IV-IV of FIGURE 2;

FIGURE 5 is a partial end elevational view of the modified form of nozzle shown in FIGURE 4;

FIGURE 6 is a developed view of the blading of the turbine nozzle constructed according to the embodiment shown in FIGURES 1 and 2;

3,052,498 Patented Nov. 6, 1962 FIGURE 7 is a developed view of the blading of the turbine nozzles of the present invention and constructed in accordance with the embodiment thereof shown in FIGURES 4 and 5; and

FIGURE 8 is a cross-sectional view of the turbine rotor drive transmitting key and locking device taken along the lines VIII-VIII of FIGURE 1.

As shown on the drawings:

The combined turbine drive and fluid pump of the present invention is shown in somewhat greater than full size dimensions in FIGURE 1. There, the right hand portion of the apparatus operates as a turbine While the left hand end of the device transforms the work energy supplied by the turbine into a centrifugal pumping action for pressurizing a liquid or gaseous medium such as, for example, gasoline or similar fuel for aircraft.

As shown in the figures and as was originally disclosed in our patent application identified above, the assembly comprises a three part housing 10 composed of a central pump housing 11, a pump inlet housing 12 and an air circulating housing 13 provided with an axial air flow controlling housing 14. The central housing 11 is provided with an axially extending bore 15 in which a drive shaft 16 is mounted by means of conventional ball bearings 17 and 18. Axial movement of the shaft 16 is prevented by the shoulders 19 in the bore 15, the metal spacing sleeve 20, the spring retainer 21 and the abutment wall 22 secured to the housing 11 by means countersunk screws 23.

The drive shaft 16 carries a turbine rotor R at its right hand, or turbine end. The rotor hub 25 is abutted against the thrust abutment 26, and is maintained axially positioned thereagainst by means of a radial key 27 positioned in a diametrical slot 28 in the shaft 16 and main- .tained in position by means of a threaded nut 29.

As may be seen from a consideration of FIGURES 1 and 2, air entering the housing 13 by means of the air inlet 13a passes around the circumference of the air circulation housing 13 and is directed axially therefrom through the nozzle plate 30 by the nozzle vanes 30a as indicated by the arrows 31. As is shown in FIGURE 1, the nozzle plate 30, which will be more fully described below, is secured by screws 32 to an intermediate support member or vane support portion 33 which is in turn secured to the central housing 11 by means of the screws 23. The intermediate support 33 may be integral with or otherwise permanently secured to the innermost portion 131) of the housing 13 or, as an alternative method of manufacture, the support 33 may instead bear a sliding 'fit relationship with the portion 13b at 33a to thereby provide a fluid tight seal.

In the general arrangement above set forth, compressed air introduced in the direction of the arrow shown in FIGURE 2 through the inlet 13a passes through the nozzle passages 30]) and impinges vanes 25a of the turbine rotor R, thereby rotating the shaft 16 through the key 27. The shaft 16 is of course drivingly connected to the centrifugal pump rotor 35.

The pump rotor 35 draws low pressure fuel or the like from an inlet 36 and delivers the fuel through centrifugal action to rotor outlet 37. From thence it travels axially through diffuser passages 38 to a collecting ring 39 from which the fuel is delivered through exit 40.

As earlier described in application Serial No. 427,599, the rotor 35 is maintained in axial and radial alignment by means of bearing and wear surfaces 41 and 42, as well as by the bearings 17 and 18. Although the rotor 35 may be secured to the shaft 16 in a number of ways, one satisfactory coupling is shown in the drawings. There, therotor 35 is splined to a drive member 43 which is in turn keyed axially at 44 to the shaft 16. The rotor 3 35 is maintained in its axial position relative to the shaft 16 by means of a spacer sleeve 45 which cooperates with a combined abutment and seal 46 to maintain the rotor 35 a fixed distance from abutment 47 on the left hand end of the shaft 16.

Pressure from the pump rotor outlet 37 may leak into cavity 48, and this leakage is prevented from passing through the bore by means of the seal plate 46 which cooperates with the spring biased wipers 4-9 and 50. While this arrangement has proven very effective in preventing leakage of the pressurized fluid medium, it is to be understood that other types of seals may be utilized if desired without departing from the scope of the present invention.

As may be seen from a consideration of FIGURE 1, the pressurized fluid entering the collecting ring 39 from the pump rotor 35 may circulate past the radial reenforcing ribs 51 into the portion of the collecting ring 39 immediately within the inner wall 13]) of the housing 13. Thus, the compressed fluid circulates in heat transfer relationship with the incoming compressed air within the turbine inlet housing 13. Likewise, the fluid from the pump rotor 35 is also in heat transfer relationship with the bearings 17 and 18 which are fixedly mounted within the bore 15. It will be apparent, therefore, that when the bearings 17 and 18 develop excessive heat, heat will be dissipated to the compressed fluid in the collecting ring 39 of the housing 11, as well as to the compressed gas within the chamber 13. The spring force urging the key 27 in the axial direction is provided by means of the spring flanges 29a on the nut 29. As may be seen from FIG- URE l, the flange 29a provides an overhanging lip which combines with the recess 2% to permit a deflection of the flange 29a upon the application of a high rotative torque to the nut 29. Thus, when the nut 29 is tightened down against the key 27, the flange 29a is deflected and a resilient set is provided therein. When during operation the rotor R contracts axially, the flange 29a moves axially with the key 27 to maintain the key in tight engagement with the rotor R, and the rotor itself in tight engagement with the abutment plate 26 thereby providing a constant, extremely tight, connection.

In the second place, an extremely eflicient coupling is provided through the use of the radial key 27 since the strength of the hub of the rotor R is increased through the elimination of axially extending spline grooves of the conventional type. It should be remembered that the axially extending splines of a conventional connection not only detract from the strength of the hub through a reduction in the metal, and hence the eflective thickness of the hub, but also provide a notch effect causing a localization of the stresses at the minimum radial thickness of the hub. This concentration of stress causes a serious weakening of the hub, which is substantially in excess of the weakening elfect of the removal of material only.

The apparatus of the present invention includes an extremely simple turbine nozzle and vane construction, this being the invention to which the instant application is principally directed. Through the use of a small diameter hub 25, as above described, short rotor vanes 25a, which vanes extend axially relatively a great distance, may be provided. By means of this construction, a minimum number of turbine buckets may be utilized, thereby providing a large flow area. This permits the development of a considerable amount of power compared to larger diameter turbines in which a greater percentage of the air passageway must of necessity comprise vane structure.

Simplified manufacture of the nozzle and rotor of the turbine and improved operation are provided through the provision of the exhaust housing 14 as a combined shroud for the IotOr and shroud for the nozzle blades.

As may be seen from FIGURE 1, the housing 14 provides a continuous and generally conically convergent shaped peripheral confining surface 14a for the air throughout its convergent flow through the nozzle openlugs 30 as well as its diffusion or divergency in the turbine blading 25a. Through this arrangement, a simple, a single, outer shroud element 14 is permitted. It is to be seen in this connection that the rotor vanes 25a and nozzle plate vanes Stla are in substantial contact with the inner surface 14a of the housing 14, and that the rotor R and nozzle plate 3'0 are immediately adjacent one another. Further, the hub portion 25 of the rotor R terminates radially at essentially the outer radial extremity of the nozzle plate hub portion.

The elimination of the need of any outer shroud for either the rotor R or the nozzle structure 30 additionally permits the manufacture of both the rotor and the nozzle by means of conventional milling cutters. Thus, the blading 30a of the nozzle blade 30 may be manufactured by indexing the blade 3%) on a conventional milling machine and moving the milling cutter in a direction of the arrow shown in FIGURES l and 6 relative to the blade 39. Movement of the milling cutter along the line indicated by the arrow 55 automatically causes a converging nozzle passage 30b to be cut into the plate 30.

The above method of manufacture is extremely simple and, further, may be utilized with only a slight modification to provide a nozzle capable of supersonic operation. Thus, as may be seen particularly from a consideration of FIGURES 4 and 7, a nozzle plate may be provided with converging-diverging nozzle passageways 60a by setting up the milling machine as above described and passing the milling cutter along a helical path shown by the arrow 66 in FIGURES 4 and 7, and then tilting the nozzle plate 60 in the opposite direction about its central axis relative to the longitudinal axis 16 and passing the milling cutter along a helical path indicated by the arrows 67 in FIGURES 4 and 7.

This two step milling operation provides a converging nozzle passageway in the direction of the arrow 66 until the minimum area neck 68 is reached, at which time the passage begins to diverge. Since, as is well known in the art, a continuous flow passage which is to excelerate the. velocity of a gas from an initial sub-sonic value to a supersonic value must comprise a convergent nozzle passage followed by a diverging section, it will be apparent that the nozzle passageways manufactured as above described, operate suitably to provide supersonic flow entering the turbine wheel R, thus providing extremely high speed, as well as eflicient operation. Likewise, as is well known, the provision of a continuously converging nozzle passageway as shown in FIGURE 1 provides in increasing velocity of the gas reaching a maximum of the speed of sound as it leaves the nozzle passages 60a and enters the rotor R.

From the above discussion, it will be apparent that the nozzle plates constructed according to the present invention may very simply be manufactured through the use of conventional milling machines rather than extremely complex machinery ordinarily used for the manufacture of nozzle passageways. This permits extremely inexpensive construction and in many cases even more important, permits manufacture of such pump and turbine structures by manufacturing concerns not having the complex machinery ordinarily associated with manufacture of turbine nozzles and other complex turbine blade forms. This simplified blading, when taken with the remainder of the very compact structure provides an unusually simple and thermodynamically superior pump and turbine structure capable of efficient use where compactness, eflicient cooling and simplicity are required.

It is to be understood that various modifications may be effected in the structures herein disclosed without departing from the novel concepts of the present invention.

We claim as our invention:

1. A nozzle and rotor combination, comprising a continuous annular housing open at opposite ends and having a continuous conical inner surface diverging from a discharge end to an inlet end providing an axially outwardly convergent fluid flow directing surface at the discharge end thereof, an inlet nozzle plate extending axially within said housing at said inlet end thereof having a plurality of vanes extending radially therefrom into substantial contact with said surface of said housing, and a turbine rotor mounted within said housing between said nozzle plate and said discharge end of the housing and having vanes thereon extending radially into substantial contact with said surface of said housing, whereby said housing surface provides a one piece continuous flow controlling path through said nozzle plate and through said rotor.

2 A nozzle and rotor combination, comprising a continuous annular housing open at opposite ends and providing a continuous conical converging fluid flow directing surface from the inlet end to the discharge end thereof, shaft means supported concentrically within said housing, an inlet nozzle plate. extending axially within said housing at said inlet end and having a plurality of vanes extending radially therefrom into substantial contact with said surface of said housing, and a turbine rotor supported by said shaft means at one end thereof and located within said housing between the discharge end thereof and said noz zle plate, said rotor having vanes thereon extending radially into substantial contact with said surface of said housing, whereby said housing surface provides a one piece continuous flow controlling path through said nozzle plate and through said rotor.

3. A nozzle and rotor combination, comprising a continuous annular housing open at opposite ends and having a generally conical inner periphery providing a continuous converging wall from an inlet open end to an outlet open end, an inlet nozzle plate extending axially within said housing at said inlet end and having a plurality of vanes extending radially therefrom into substantial contact with said surface of said housing, said nozzle plate and said surface of said housing radially outwardly of said nozzle plate vanes providing a convergent fluid flow path through said nozzle plate, and a turbine rotor mounted within said housing and extending axially from said discharge end thereof to said nozzle plate and having a hub portion with vanes thereon extending radially into substantial contact with said surface of said housing, said rotor hub portion and said surface of said housing radially outwardly of the rotor vanes providing a diffusing divergent fluid flow path through said rotor.

References Cited in the file of this patent UNITED STATES PATENTS 1,427,179 Waller Aug. 29, 1922 1,894,393 Bigelow Jan. 17, 1933 2,252,817 Van Rijswijk Aug. 19, 1941 2,391,786 Kenney Dec. 25, 1945 2,646,209 Galliot July 21, 1953 2,701,528 Angell Feb. 8, 1955 2,715,367 Kodet et al Aug. 16, 1955 2,750,892 Johnson June 19, 1956 2,839,005 Means June 17, 1958

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