US1012749A - Blading means for turbines. - Google Patents

Description

0 E. SWEET. BLADING MEANS FOR TURBINES.

APPLICATION FILED JULY 30, 1908.

1,012,749. Patented Dec. 26, 1911.

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24,, A TORNEY IN FACT.

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CHARLES E. SWEET, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO THE COLONIAL TRUST COMPANY. TRUSTEE, OF PITTSBURGH, PENNSYL- VANIA, A CORPORATION OF PENNSYLVANIA.

BLADING MEANS FOR TURBINES.

Specilicatibn of Letters Patent.

Patented Dec. 26, 1911.

Y Applicatidn filed July 30, 1908. Serial No. 446,100.

To all whom it may concern:

Be it known that I, CHARLES E. SWEET, a citizen of the United States, and a resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have made a new and useful Invention in Blading Means for Turbines, of which the following is a specification.

This invention relates to elastic fluid turbines and more particularly to blading means for turbines.

An object of this invention is the production of means for assembling the blades into rings or ring segments before they are secured to the blade-carrying elements of the turbine. p

My invention contemplates assembling the blades and intermediate spacing pieces,

which are located between the bases of the blades, on a wire, then locking each spacing piece to the wire to permanently secure the blades and spacing pieces together into a segmental ring. I also contemplate providing a binding member for the outer or free ends of the blades so that the blades and pieces are permanently organized into a rigid segmental blade ring which may be secured to the blade-carrying element of the turbine.

In the drawings accompanying this application and forming a part thereof: Figure 1 is a fragmental transverse section of a rotor element in connection with blades (shown in elevation) secured thereto in accordance with by invention; Fig. 2 is a fragmental transverse section of a portion of the rotor element and a portion of the stator element of a turbine'located substantially in their relative positions and respectively pro Fig. 6 is an end view ofa spacing piece forming a detail of my, invention; Fig. 7 is an end View of a'modified form of spacing piece; and, Fig. 8 is an elevation of a blade which forms a detail of a modification of my invention.

For the sake of brevity and also for the sake of convenience of description, the terms blade and blades will be employed throughout this specification and in the claims to denote either the rotating blades or the stationary vanes of the turbine and the term blade-carryingelement will be employed to denote either the stationary or the rotating blade-carrying element.

Each blade-carrying element 10 of the turbine is provided with a plurality of under-cut blade mounting slots 11, ineach of which an annular row of blades 12 and intermediate spacing pieces 13 are secured by means of compound tapered wedges 14. Each blade 12 is substantially crescentshaped in cross-section throughout its length and is provided with a notch '15 which is located at one end of the blade near the mounting end.

The intermediate spacing pieces 13 are adapted, by their shape, to [fit snugly between the mounting ends of the blades when the blades are assembled in a ring or a ring segment. Each piece is provided with a concave face which corresponds in contour to the curvature of the convex face of the blades and a convex face which corresponds in contour to the concave faces of theblades. These faces are so inclined, relative to each other, that the blades, when assembled in rings, occupy radial positions. One lateral face of each spacing piece is inclined to correspond to the inclination of the undercut so located as to register with the notches 15 of adjacent blades when the piece and the blades are assembled. The notches .15, in

the blades and 16, in the pieces, coiiperate in receiving a wire or rod 17' which is adapted to bind the blades and spacing pieces to- 'gether. Each spacmg piece is so constructed, or the notch 16 is s out in the piece, that the piece can be positively and permanently locked in place onthe binding wire 17. In Figs. 2 and 7, I have shown a spacing piece in which the notch is so cut to provide an overhanging tip 18 which is abnormally distorted to admit the wire" 17 and which is then moved to its normal position fication in which" the bottom faces of the to secure the wire in place.

In Fig. 6 I have shown a difl'erent arrangement for securing thepiece 13 to the wire 17. The spacing piece disclosed is of.

a peculiar shape, being provided on its top face with a projecting, tip which, when calked or pressed dowln flush with the major portion of the top face, secures the piece to the wire by causing the metal of the piece,

at one edge of the notch 16, to flow inwardly and inclose the wire. Various methods may be employed for securing the piece to the Wire and it will be noted by referring to Fig. 3 that the blades are locked in place between adjacent spacing pieces when the pieces are secured to the wire.

The outer or free ends of the blades are provided with commashaped holes 19 through which a'binding wire 20 of commashaped cross section extends. The binding wire 20 is secured to the blades and is caused to space the outer or free ends of the blades by having the tail or fin portion 21, with which it.is provided, .sheared and bent over between adjacent blades. This construction, together with the binding wire 17 for, the base of the blades, assembles the blades into rigid rings or segments of rings which may be mounted 'in the blade-mounting slots 11 of the turbine.

After the blades and spacing pieces are assembled into a segmental ring, the segments a'relocated in one of the slots 11 so that the inclined faces of the intermediate spacing pieces contact with one of the undercut Walls of the slot. .The ring is then secured in place by means of the compound tapered wedges 14 which are located within the slot between the other undercut wall of the slot and the normal faces of the inter mediate spacing pieces.

The ring segments are preferably of such length that several are located within one slot. The Wedges 14 are arranged in pairs and are so constructed that, when driven home,' the two wedges of each pair conjointly form a wedge-shaped key which effectivel and which is prevented, by its shape and the shape of its component wedges, from being dislodged from the slot by centrifugal force or any other dislodging force.

In Fig. 8, I have shown a modification in which each blade 12 is provided with a cylindrical hole 22 which takes the place of the slot 15 and which is so located as to register with the notches 16 of the intermedisecures the blade rings in place ate spacing pieces 13. In assembling the blades and pieces the binding wire 17 is adapted to extend through the holes 22 and to be located in tlie notches 16 of the spacing pieces. Vith this arrangement the blades, as well as the intermediate spacing pieces, are positively locked to the wire'17.

In Fig. 5 I have shown still another modispacing pieces and the ends of the blades .are provided with registering dove-tailed notches through which a dovetailed strip 231s adaptedto extend. The blades and pieces are strung onto the ends of the strip 23 and are held in place by riveting over the ends of the strip. 1,

In accordance with the-provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to representthe best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and' ity of turbine blades assembled in a row,

intermediate spacing pieces located between the bases of adjacent blades and a binding member located in slots provided in said blades and pieces, the outer edges of the slots being distorted to close in the slots to engage the binding member.

In combination in a turbine, a plurality of blades and intermediate spacing pieces, a binding member located in slots provided in said blades and pieces, and a tip formed integrally with each piece for positively locking each piece to said member. H A. In combination in a turbine, a plural ity of blades and intermediate spacing pieces, a binding member located in slots provided in said blades and pieces, and a tip formed integrally with each'piece and adapted to be abnormally distorted to ad mit said member into the slot of said piece,

and to be bent to a normal position to secure said strip into said slot.

5. In combination in a turbine, a plural-v ity of blades having openings, a binding member adapted to extend through the openings provided in the bases of the blades, and intermediate spacing pieces, said spacing pieces having slots, the edges of which are bendable over the binding member.

6. In combination in a turbine, a plurality of alternately arranged blades and slotted intermediate spacing pieces, blades be- .ing provided with openings, a binding membet extending through the openings provided in the blades and a bendable edge for 5 the slot and closing in said'slot for permanently securing each spacing piece to said member.

In testimony whereof, I have hereunto subscribed my name this 23rd day of July,

CHARLES E. SWEET. Witnesses C. W. MOGHEE,

E.'VV. McCALLIs'rER.

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