US1518913A - Blade tie - Google Patents

Description

, 1,518,913 c. GILSON BLADE TIE Filed Aug. 29, 1921 U-Eilsnn Q INVENTOR Patented Dec. 9

UNITED STATES PATsNroFricE.

CHRISTIAN GILSQN, OF HOMEWOOD, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

BLADE TIE.

Application filed August 29, 1921. Serial No. 496,311.

To all whom it may concern:

Be it known that I, CHRISTIAN GILSON, a citizen of the United States, and a resident of vI-Iomewood, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Blade Ties, of which the following is ,a specification.

My invention relates to a blading structure for use in steam turbines and similar apparatus and it has for its object to provide apparatus of the character designated which shall serve to accurately space apart and brace turbine blades, at the same time largely preventing the vibration thereof.

In the accompanying drawing, Figure 1 is anend sectional view of a plurality of turbine blades provided with spacing and lashing means constructed in accordance with my invention, and Figure 2 is a side view in elevation of a complete series of turbine blades embodying the structure of Figure 1.

In the construction of steam turbines and like apparatus, it is well known that the respective blades are mounted in substantially parallel relationship and it is usual to join intermediate points in such blades by means of lashing Wire or similar means so as to determine the blade spacing and so as to minimize vibration. Lashingwires of this character have, in general, been placed in notches in the edges of the blades or in holes therethrough, being subsequently brazed in place. The notching or perforating of the blade has tended to weaken the structure and the brazing operation has tended to alter the composition of alloy blades and to destroy the temper of steel blades.-

WVith all the foregoing considerations in mind, I propose to attach a cross piece to each blade, as by riveting, spot welding, or forging on blade, each cross piece being provided with an outside extension ma-king con tact with the adjacent blade. Rivets or other similar means are then inserted through each extension and through the body of the cross piece to the adjacent blades so that there may be built up a composite lashing or bracing arrangement serving to stiffen the entire blading structure.

Turning to the drawing for a more detailed understanding of my invention, I show three blades of crescent-shaped crosssection at 1010 in Figure 1, these blades being mounted in substantially parallel relationship, as indicated in Figure 2, it being well understood that the blades diverge slightly toward their tips when mounted on a rotor and converge slightly toward their tips when mounted on a stator member.

A cross piece 11 is attached to the concave face of each blade, preferably adjacent the central portion of the blade, the attachment being efiected by means of rivets 1212, or by spot welding. In case spot welding is used, it may well be that the blade is actually stiffened at the point of attachment, rather than being weakened.

Each member 11 carries an offset extension 13, extending beyond the wing of the associated blade and reaching into contact with the convex face of the immediately adjacent blade. Rivets14l14t are then inserted through these extensions and through the body ofthe immediately adjacent cross piece associated with the next blade so as to tie the entire blading structure together in a simple yet rigid manner.

In the reaction type of blades illustrated the weaker portion of each blade, and therefore the portion most affected by vibration is the wing portion. It is evident from the drawings that my improved bracing members form a lashing along the weaker side of a row of blades, stiffen the body of each blade and also form a rigid bracing for a row of blades.

It will be noted that the various members 11 associated with a series of blades are in this way joined the one to the other in such a manner as to form a lashing and spacing structure of sufficient stiffness to perform the desired function, and yet, at the same time, the small amount of relative movement necessarily present between the different elements in a structure of this kind is permitted, readily allowing for the expansion and contraction caused by heating and cool- While I have shown the cross pieces as mounted on the concave faces for their respective blades, it will be obvious to those skilled in the art that they may well be f'mounted on the convex faces thereof and,

furthermore, adjustment may be made for different sizes and spacing of blading by increasing or decreasing the amount of offset of the extensions 13 and by suitable spacing of the holes therein provided for the rivets let-14.

While 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 other 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 art or as are specifically set forth in the appended claims.

. What Tclaim is '1. The combination with a series of turbine blades of crescent-shaped cross-section mounted "in substantially parallel relation, of a'transverse-member attached to the con-, cave face of each blade and having an off set extension extending into contact with the convex face of the immediately adjacent blade, and means for fastening said extension to said adjacent blade and another transverse member, whereby said blades are maintained in spaced relation and the vibration'th'ereof minimized.

2. The combination with a series of tur "bine bl'ades of crescent-shaped cross-section mounted in substantially parallel relation, of a transverse member attached to the concave face of each blade andhaving-an 0&

structure is provided, suitable for maintaining the spacing of said blades and for minimizing the vibration thereof.

3. In a row of turbine blades, a bracing member between adjacent blades, each member being secured to one blade and having an offset portion secured to an adj acent blade and another bracing member to form lashing for the row of blades.

4. The combination of a turbine blade and a member attached to the blade, said member extending transversely from a point near the inlet side of the blade to a point beyond the outlet side thereof and having an offset portion attached to an adjacent blade and another member in the same row of blades.

5. The combination of a turbine blade and a member attached to the blade at a point intermediate the root and the tip, said member extending transversely from a point near the inlet side of the blade to a point beyond the outlet side thereof, and having an offset portion attachedto an adjacent blade and another member in the same row of blades.

6. The combination of a turbine blade and a member attached to the blade at a point intermediate the root and the tip, said member extending transversely froma point near point near the inlet side of the blade to a point beyond the outlet side thereof, said member being secured to the blade at a plurality of points including a point near the wing portion thereof, and-having an-olfset portion-secured to thewing portionof an adjacent-blade in the same row.

8. The combination of-a turbine bladeand a member extending transversely from a point near the inlet side of 5 the "blade to -a point beyond the outlet side thereof, said member being secured to'the blade at a plurality'of points including a point near the wing portion thereof, and having an :ofiset portion secured to the wing portion of an adjacent blade in the same TOW, and another transversely extending member.

9. The combination of a turbine blade and a member extending transversely from a point near the inlet side of the blade to-a point beyond the outlet side thereof, said memberbeing secured to the-blade at, a plurality of points including a point near" the wing portion thereof, and having an offset portion secured to the wing portion-of an adjacent blade in the same row and another transversely extending member, providing lashing between'the wing portionsofthe blades and bracing for the blade structure.

'10. The combination of a turbine'blade and a member extending transversely from a point near the inlet side of the blade to a point beyond the outlet side thereof, said member being secured to the blade at a'plurality of points including apoint near the wing portion thereof, and havingan offset portion secured to tlie'wing portion of-a'n adjacent blade in the same row and another transversely extending member, forming lashing between thewing' portions of the blades, and sti flening'fo'r each blade.

11. Ina row of turbine blades, the combination of 'a'blade and a bracing member, saidbracing member being secured-to the concave face'jof the blade, andexten'ding substantially across the blade from a point nearthe inlet edge to a point beyond the outlet edge thereof, and having-an offset portion engaging with the convex'faoe ofan adjacent blade at a point near the out let edge thereof, and to another bracing member.

12. The combination of a'turbi'ne-blade and a blade brace, said brace being secured at a plurality of points across the concave face of the blade, including a point near the wing. portion. of the-blade and being disposed intermediate the root and tipofthe lllfi blade and having an offset portion secured to the wing portion of an adjacent blade in the same row and to another blade brace.

13. The combination of a turbine blade and a blade brace, said brace being secured at a plurality of points across the concave face of the blade, including a point near the Wing portion of the blade, and being disposed intermediate the root and tip of the blade and having an offset portion secured to the Wing portion of an adjacent blade in the same I'O-W and to the blade brace of the adjacent blade.

14. The combination. of a turbine blade and a blade brace, said brace being secured at a plurality of points across the concave face of the blade, including a point near the Wing portion of the blade, and being disposed intermediate the root and tip of the blade, and having an oifset portion secured to the Wing portion of an adjacent blade in the same row and to the blade brace of the adjacent blade, forming lashing along the wing portion sides of the blades.

In testimony whereof, I have hereunto subscribed my name this 19th day of August, 1921.

CHRISTIAN GILSON.

Images