US2605997A

US2605997A - Mounting for the guide vanes of axial-flow compressors and turbines

Info

Publication number: US2605997A
Application number: US727520A
Authority: US
Inventors: Lombard Adrian Albert; Morley Frederick Willia Walton
Original assignee: Rolls Royce PLC
Current assignee: Rolls Royce PLC
Priority date: 1946-04-05
Filing date: 1947-02-10
Publication date: 1952-08-05
Anticipated expiration: 1969-08-05
Also published as: FR944756A; CH257532A; BE487115A; GB611326A

Description

Aug. 5, 1952 A. A. LOMBARD ET AL 2,605,997

MOUNTING FOR THE GUIDE VANES OF AXIAL-FLOW COMPRESSORS AND TURBINES Filed Feb. 10, 1947 Patented Aug. 5, 1952 UNITED: STATES grant OFFICE MOUNTING Foe. THE GUIDE VAN-E's F AXIAL FLoW comrnnssons AND TURBINES British company Application February 10, 1947, Serial No. 727,520

In Great Britain April-y 1946 I l This invention relates to guide vanes for axial flow turbines and compressors of the type in which the blades are mounted between inner and outer rings. This invention has for its object to provide means for minimising distortion or displacement of 'the blades in such blade mountings during assembly and inuse.

According to the present invention a nozzle guide vane assembly for-axial flow turbines and compressors of the typeset forth is provided in which guide vanes are mounted at their inner and outer ends respectively in inner and outer rings so as to be located circumferentially relative thereto and to have freedom in the eneral axial sense thereof, except at one point in axial section where such freedom is'restra'ined by anchorage of, one of the vane ends to, the associated ring.

According to another feature of the present invention the two ends of each guide vane are mounted in the two rings respectively so as to be located relatively to the rings transversely of the length of the said vane-ends but to be free to move relatively to the rings in the general direction of the length of said vane-ends except at one point in one end where that end is also located on the associated ring in said direction. Preferably each vane is loosely splined to each ring and is formed with a projecting foot at one corner to engage an open-ended recess in one ring and to be retained therein by another part closing the open end of the recess.

In order that the nature of the invention may be fully appreciated two applications of the invention to the nozzle guide vanes of an internal combustion turbine will now be described, by way of example only, with reference to the ac-- companying drawings wherein:

Figure 1 is a sectional elevation of a part of a nozzle guide vane assembly.

Figure 2 is a section on the line 2-2 ofFigure 1, g

Figure 3 is a view similar to Figure 1 and showing an alternative and preferred embodiment o'f'the invention, and

Figure 4 is a section on the line 4-4 of Figure 3. 7

Referring to Figures 1 and 2: the nozzle guide 'vane, which is generally indicated by the reference numeral '5, comprises a vane portion 6 integrally formed at each end with a tablet l, 8. Each tablet is a parallelogram or rectangle in form when the vane-is viewed end-on. The vane is mounted between an'i'nner-ring 9' and an outer (and concentric) ring IObysliding the inner and outer tablets l, 8 respectively into slots ll formed '10 Claims. (01. ass-'77) apart of the vane shroud.

in the opposed surfaces, of the rings, the slots being helically disposed'of' the, rings and the tablets arranged to. mat-ch therewith.

Each tablet isa'lojose, fit in its. slot so that, the ends of vane 5 .are loosely splinedtfio rin s 3 and It. In forming the slots H there are produced splines l2 and it is arrangfidthat theirdepth be that of their associated tablets. .In this way the splines lie flush with the internal surfaces of the tablets 7, 8 (see Figure 2), and constitute The tablet o'f eac'h vane isformedwith a foot l3 projecting from one, side race thereof and the "foot engages-,ina recess M inringfl (Figure '1). The inner and outer rings 9 and HI respectively are secured to. an, annular nozzle 'box, the inner sectiorrllS of which abuts the end of ring 9 so as tio; retain. th foot 13 loosely in the recess'l l. The box 15 is formed witha circular flange it which overlies the axially'projecting partof foot l3.and.fit s againsttablet l. The outer tablett also engages'an abutment 20 though in certain circumstances this may be dispensed with. J v w The vanes 5 are each assembled in'rings 9 and HI so as to lie side by side around the rings and are all engaged by flange l6. 7 l f In the alternative andpreferred construction shown in Figures 3, and 4', the tabletsl and 8' are of such circumferential extent. that the sides of the tablets of adjacent vanes almostv abut (Figure 4). Of course withthis construction the Ita-bletsi, 8" cannot be accommodated in slots II and to locate, the vanes on the rings sf and i6 each tablet- 'i', 8' is formed respectively with a spline IT and i8 on its exterior surface to engage the slots. The foot i3! is formed atone end of the inner spline H. The central part of each spline l-i and; I8, is machined away, as at Hi, to reduce the tendency :forthey vaneto bind in the rings. This construction is preferred because as thegtablets nearly abut-they form the complete shroud and shield the support rings from the-hot gases.

It will be seen that the guide vanes :5" can be assembled in rings 9? and [0 without risk of distortion, which is present if they are riveted or welded to the rings, end-each vane is located at one corner only (by foot t3) so that it can expand freely both radially and axially of the rings. Moreover, the inner and outer rings can move axially and circum-ferentially relative to each other, due, for instance, to temperature themselves and without displacing them, thus possibly varying their passage shape or throat area. The present invention is thus particularly applicable to the nozzle guide vanes for an internal combustion turbine in that the risk of distortion due to-the high temperature at which such vanes operate is minimised. The vanes will be Y subjected only to stresses resulting from gas pressure and are not stressed as the result of differential expansion of the vanes and rings. The minimisation of distortion is of importance as it reduces variations in the throat area between the trailing edge of each vane and the adjacent vane on its concave side, which area controls the work capacity of such turbines.

We claim:

1. In axial-flow turbines and compressors, the combination of a supporting structure, an outer ring secured to the supporting structure and having its inner surface slotted by a plurality of circumferentially spaced slots, an inner ring secured to the supporting structure in the plane of the the Outer ri nd h ving its outer surface slotted by a plurality of circumferentially spaced slots, the sides of said slots in both rings extending across the rings from one edge thereof in a direction having an axial component, a plurality of guide vane members having tablets formed at the outer and inner ends of the vanes, the tablets at the outer ends of the vanes each engaging a slot in the outer ring and the tablets at the inner ends of the vanes each engaging a slot in the inner ring, and means locating in an axial direction one of the tablets associated with each guide vane atone end only of its sl'ot permitting free expansion and contraction of said vanes relatively to said rings in an axial and a radial direction.

2. In axial-flow turbines and compressors, the combination of a supporting structure, an outer ring secured to the supporting structure and having its inner surface slotted by a plurality of circumferentiallyspaced slots, an inner ring secured to the supporting structure in the plane of the outer ring and having its outer surface slotted by a plurality of circumferentially spaced slots, the sides of said, slots in both rings extending across the rings from one edge thereof in a direction having an axial component, a plurality of guide vane members having tablets formed at the outer and inner ends of the vanes, said tablets extending circumferentially of said rings into proximity'with one another and constituting shroud rings for the vanes, a spline on each tablet engaging a slot in its adjacent ring and meanslocating in an axial direction one end onlyof one of the tablets associated with-each vane.

3. In axial-flow turbines and compressors, the combination of a s pporting structure, an outer ring secured to the supporting structure and having its inner surface slotted by a plurality of circumferentially spaced slots, an inner ring secured to the supporting structure in the plane of the outer ring and having its outer surface slotted by a plurality of circumferentially spaced slots, the sides of said slots in both rings extending across the rings from one edge thereof in a direction having an axial component. a plurality of guide vane members having tablets formed at the outer and inner ends of the vanes, the tablets atthe outer ends of the vanes each engaging a slot in the outer ring and the tablets at the inner ends of the vanes each engaging a slot in the inner ring and said tablets lying flush within the slots to constitute at least a part of shroud rings for the vanes, and means locating in an axial direction one of the tablets associated with each guide vane at one end only of its slot permitting free expansion and contraction of said vanes relatively to said rings in an axial and a radial direction.

4. In axial-flow turbines and compressors, the combination of a supporting structure, an outer ring secured to the supporting structure and having its inner surface slotted a plurality of circumferentially spaced slots, an inner ring secured to the supporting structure in the plane of the outer ring and having its outer surface slotted by a plurality of circumferentially spaced slots, the sides of said slots in both rings extending across the rings from one edge thereof in a direction having an axial component, a plurality of guide vane members having tablets formed at the outer and inner ends of the vanes, the tablets at the outer ends of the vanes each engaging a slot in the outer ring and the tablets at the inner ends of the vanes each engaging a slot in the inner ring, a projecting foot at one end of one of the tablets associated with each guide vane, an open-ended recess in the ring engaged by said tablet receiving the said foot within it, and means closing the end of said recess to locate said end of the tablet in an axial and radial direction.

5. In axial-flow turbines and compressors, the combination of a supporting structure, an outer ring secured to the supporting structure and having its inner surface slotted a plurality of circumferentially spaced slots, an inner ring secured to the supporting structure in the plane of the outer ring'and having its outer surface slotted by a plurality of circumferentially spaced slots, the sides of said slots in both rings extending across the rings from one edge thereof in a direction having an axial component, a plurality of guide vane.members having tablets formed at the outer and inner ends of the vanes, said tablets extending circumferentially of said rings into proximity with one another and constituting shroud rings for the vanes, a spline at each end of each tablet engaging a slot in the ring adjacent said tablet, a projecting foot on one of the splines on the tablets associated with each guide vane, an open-ended recess in the ring engaged by the spline having the projecting foot, said foot being received in said recess and means closing the recess to locate the foot in a radial and axial direction.

6. In axial-flow turbines and compressors, the

combination of .a supporting structure. an outer ring secured to the supporting structure and having on its inner surface a plurality of circumferentially spaced slots of which the sides extend across the ring from one edge thereof in a direction having an axial component, an inner ring secured to said supporting structure in the plane of the said outer ring and having on its outer surface a plurality of circumferentially spaced slots of which the sides extend across the ring from the edge thereof corresponding to said one end only of its slot permitting free expancombination of a supporting structure, an outer ring secured to the supporting structure and having on its inner surface a plurality of circumferentially spaced slots of which the sides extend across the ring from one edge thereof in a direction having an axial component, an inner ring secured to said supporting structure in the plane of the said outer ring and having on its outer surface a plurality of circumferentially spaced slots of which the sides extend across the ring from the edge thereof corresponding to said edge of said outer ring in a direction having an axial component, a plurality of guide-vanes each formed with a tablet at each end, said tablets extending circumferentially of said rings into proximity with one another and constituting shroud-rings for said vanes, a spline on each tablet engaging a slot in its adjacent ring, and means locating in an axial direction one end only of one tablet of each vane.

8. In axial-flow turbines and compressors, the combination of a supporting structure, an outer ring secured to the supporting structure and having on its inner surface a plurality of circumferentially spaced slots of which the sides extend across the ring from one edge thereof in a direction having an axial component, an inner ring secured to said supporting structure in the plane of the said outer ring and having on its outer surface a plurality of circumferentially spaced slots of which the sides extend across the ring from the edge thereof corresponding to said edge of said outer ring in a direction having an axial component, a plurality of guide-vanes each formed with a tablet at each end, said tablets respectively engaging a slot in said outer ring and a slot in said inner ring and lying flush therein to constitute at least a part of shroudrings for said vanes and means locating in an axial direction one tablet of each guide-vane at one end only of its slot.

9. In axial-flow turbines and compressors, the combination of a supporting structure, an outer ring secured to the supporting structure and having on its inner surface a plurality of circumferentially spaced slots of which the sides extend across the ring from one edge thereof in a direction having an axial component, an inner ring secured to said supporting structure in the plane of the said outer ring and having on its outer surface a plurality of circumferentially spaced slots of which the sides extend across the ring from the edge thereof corresponding to said edge of said outer ring in a direction having an axial component, a plurality of guide-vanes each formed with a tablet at each end, a projecting foot at one end of one tablet of each vane, an open-ended recessin the ring engaged by said tablet receiving said foot Within it and means closing th end of said recess to locate the said tablet and vane in an axial and a radial direction.

10. In axial flow turbines and compressors, the

combination of a supporting structure, an outer ring secured to the supporting structure and having on its inner surface a plurality of circumferentially spaced slots of which the sides extend across the ring from one edge thereof in a direction having an axial component, an inner ring secured to said supporting structure in the plane of the said outer ring and having on its outer surface a plurality of circumferentially spaced slots of which the sides extend across the rin from the edge thereof corresponding to said edge of said outer ring in a direction having an axial component, a plurality of guide-vanes each formed with a tablet at each end, said tablets extending circumferentially of said rings into proximity with one another to constitute shroudrings for said vanes, a spline at each end of each tablet engaging a slot in the ring receiving said tablet, a projecting foot on one of said splines, an open-ended recess in th ring receiving said foot and means closing the end of said recess.

ADRIAN ALBERT LOMBARD. FREDERICK WILLIAM WALTON MORLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,402,418 Kroon June18, 1946 2,427,244 Warner Sept. 9, 1947 FOREIGN PATENTS Number Country Date 16,889 Great Britain July 15, 1910 107,788 Sweden 1943