US1762361A - Turbine blade - Google Patents

Description

June 10, 1930.

INVENTOR H-Efichmidl' Patented lune 10, 1930 wearer PATENT HENRY F. SCHMIDT, F LANSDOWNE, PENNSYLVANIA, ASSlG-NOB TO WESTINGHOUSE ELECTRIC 8; MANUFACTURING- COIWIPANY, A GOIRPQBATION 0F PENNSYLVANIA TURBINE BLADE Application filed February 28, 1928.

My invention relates to elastic fluid turbines and it has for an object to improve the blading thereof from the points of view of manufacture and assembly.

A further object of my invention is to provide a turbine wheel having forward and astern, or stopping buckets which may be readily and economically manufactured from suitable mate *ials and which possess requisite strength.

An additional object of my invention is to provide a turbine blade formed from metallic sheet or plate material and having a root portion provided with deformable holding parts.

A more particular object is to so shape the deformable parts at one side of the root portions so as to provide reversing, or stopping buckets.

A. further object of my invention is to provide a turbine wheel formed at its peripheral portion with inwardly-facing abutment means at one side, an annular groove at the other side, and radial grooves or slots inter secting the abutment means and the annular groove together with blades having root portions adapted to fit the radial slots and the root portions being provided with lateral tabs, the tabs at one side being deformable to fit the abutment means to hold the blades in place and the tabs at the other side being suitably shaped and deformable so as to divide the annular groove into buckets and to cooperate with said groove to assist in holding the blades in place with respect to the wheel.

These and other objects are effected by my invention as will be apparent from the fol lowing description and claims taken in connection with the drawings, in which:

Figs. 1 and 2 are fragmentary side elevational views, taken from opposite sides, of a turbine wheel having blading made in accordance with my invention, the blades being spaced somewhat farther apart than would 45 be the case in an actual turbine in order to more clearly show the construction;

Fig. 3 a fragmentary sectional view showing my improved blading with cooperating nozzles Fig. at is a fragmentary sectional view of a Serial No. 257,75t7.

turbine wheel suitable for use with my improved blading;

Fig. 5 is a detail view of a blade blank; and

Fig. (3 is a plan view showing the formed blade and root portions.

Referring now to the drawings more in detail, in Figs. 1, 2, 3 and i, I show a turbine wheel 10 having an annular groove 11 disposed in one face of the wheel adjacent the periphery thereof so as to provide inwardlyfacing abutment means 12 and similarly (lisposed in the opposite face of the wheel is an annular concave groove 12-3. The wheel 10 is also provided with longitudinally extending radial slots 14, which intersect the grooves 11 and 13.

The turbine blades 15 are provided with root portions 16 which. fit the radial slots 1 1 and the root portions have deformable latcral tabs 17at one side for cooperation with the groove 11 and the abutment means 12 in order to hold the blades in place while at the other side are suitably shaped and deformable tabs 18 which fit the annular concave groove 13 to divide the latter into a plu- 'ality of turbine buckets 19 (see Fig. 2)

Upon reference to Fig. 5, it will be seen that in the formation of my improved blad ing, I first provide a suitably shaped blank having a main blade portion which is capable of being formed into a blade having a suitable contour and having a root portion 16 provided with the lateral tabs 17 and 18 which are deformable in order to constitute blade-holding means as well as to divide the annular concave groove 13 into a plurality of reversing, or stopping buckets 19.

In Fig. 6, I show the ultimate shape to which a blank such as shown in Fig. 5 may be deformed and bent, the upper portion of the blank being formed to provide the main or ahead blades 15, whereas the lower or root portion of the blank is deformed to provioe the holding and bucketforming tabs 17 and 9 18. ills may be seen from Fig. 6, the tab 17 is shown extending forwardly of the face of the main blade portion 15 whereas the tab 18 shown extending rearwardly of the back of the main blade portion 15, the angle of inclination of the tab 18 to the plane of rotation being approximately 30.

In assembling the blading With respect to the wheel, blades may be provided having the tab portions 17 and 18 undeformed or flat with respect to the root portion 16, the root portions being slid into the radial slots 14 and the tabs 17 and 18 being bent to fit the annular slot 11 and the abutment means 12 and to fit the concave groove 13 for the purposes stated, It will be apparent that either the tabs 17 or the tabs 18 may be deformed or bent before assembly with respect to the wheel, for it would be possible to slide the root portions radially and longitudinally through the slots 14 until either the tabs 17 or the tabs 18 limited such sliding motion. It will also be observed that the holding and bucket forming tabs 17 and 18 are so arranged with respect to the annular grooves 11 and 13, respectively, that the radial slots 14: are completely filled between these grooves and the base of the blade by the roots 16. Hence, it is assured that there will be no leakage through the slots 14 and that the walls of the buckets will be Well defined.

In Fig. 3 I show the turbine wheel 10 having the blades 15 assembled with respect thereto, the blades having the tabs 17 and 18 deformed to constitute holding and bucketforming parts cooperating with the wheel proper. An ahead nozzle is shown at 20 for discharging high velocity motive fluid against the blade 15, and nozzle means is provided at 21 for discharging high velocity motive fluid into the buckets 19, the nozzle means 20 and the blades 15 being so arranged as to secure ahead operation, and the buckets 19 and the nozzle means 21 being so arranged as to secure astern, reversing, or stopping operation.

From the foregoing it will be apparent that I have provided turbine blading which may be readily and economically manufactured from desirable sheet or plate material, the main blade portions being suitably formed or shaped whereas the root portions are provided with deformable parts constituting holding means. Also, it will be apparent that, due to this construction, a very economical way is provided for the formation of an astern or stopping element, for it is only necessary to provide the turbine wheel with an annular concave groove and to so form the lateral tabs or holding means at one side of the blading that such tabs may be deformed to fit the concave groove in such a way as to di vide the latter into buckets.

WVhile I have shown the bucket forming tabs 18 arranged below the tabs 17, it will be obvious that these tabs may be arranged directly opposite one another, or that the tabs 18 may be arranged above the tabs 17 should conditions render such an arrangement desirable.

l/Vhile I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior artor as are specifically set forth in the appended claims.

What I claim is:

1. A turbine blade formed from sheet metal and having a deformable holding part carried by the root portion and bent relative thereto about a radial axis.

2. A turbine blade formed from sheet metal and provided with a root portion having laterally-extending deformable holding means bent relative thereto about a radial axis.

3. A turbine blade formed from sheet metal and provided with a root portion having laterally-extending deformable tabs bent relative thereto about radial axes.

4. A turbine blade formed from sheet metal and comprising a main blade portion and a root portion and the root portion having deformable lateral holding and bucket-forming tabs.

5. The combination of a turbine wheel having an annular groove at one side, abutment means at the other side, and radially-extending slots; and blades having root portions fitting the slots and the root portions being provided, at one side, with parts fitting the abutment means and, at the other side, with parts fitting said annular groove to divide the latter into buckets.

6. The combination of a turbine Wheel having an annular concave groove at one side, annularly-disposed and inwardly-facing abutment means at the other side, and radial-- ly-extending slots intersecting said abutment means and said groove; and blades having root portions fitting the slots and the root portions being provided with lateral tabs, the tabs at one side being deformable for .cooperation with the abutment means and the tabs at the other side being deformable to divide the annular concave groove into a plurality of buckets.

7. The combination with a turbine Wheel having a surface in the peripheral portion facing radially inwardly and transverse slot-s across the peripheral portion and intersect-- ing said surface, of sheet metal blades including fluid receiving portions and root portions inserted in the slots, said root portions having tabs bent substantially about radial axes and abutting said inwardly facing surface to hold the blades on the wheel.

8. The combination with a turbine wheel, of an annular row of sheet metal blades mounted thereon, said blades including portions receiving motive fluid directed thereagainst from one side of the row and deflecting the same to the opposite side of the roW and also including portions receiving motive fluid directed thereagainst from one side of the row and deflecting the same back to said last-mentioned side.

9. The combination with a turbine rotor, of a blade formed of sheet metal mounted thereon and having one part bent to receive motive fluid for rotation in one direction and another part bent to receive motive fluid for rotation in the opposite direction.

10. The combination with a turbine wheel having a groove in one side of the peripheral portion and slots across the peripheral portion intersecting the groove, of blades inserted in the slots having portions outwardly of the peripheral portion formed to receive motive fluid for rotation in one direction and other portions in the groove formed to receive motive fluid for rotation in the opposite direction, and means for retaining the blades in the slots.

11. The combination with a turbine wheel having a groove in one side of the peripheral portion and slots across the peripheral portion intersecting the groove, of blades formed of sheet material inserted in the slots having portions outwardly of the peripheral portion bent to receive motive fluid for rotation in one direction and other portions in the groove bent to receive motive fluid for rotation in the opposite direction, and means for retaining the blades in the slots.

12. A turbine rotor consisting of a rotatable wheel and sheet metal blade members mounted thereon, said rotor having curved blade portions formed by said blade members for rotation of the rotor in one direction and having buckets of curved form and including a part of the blade members for rotation in the opposite direction.

13. A turbine rotor consisting of a rotatable wheel and blades mounted thereon, said blades having curved blade portions for operation of the rotor in one direction and the blades and the wheel having cooperating parts forming buckets for operation in the reverse direction.

In testimony whereof, I have hereunto subscribed my name this 27th day of February, 1928.

HENRY F. SCHMIDT.

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