US1618285A

US1618285A - Blade lashing

Info

Publication number: US1618285A
Authority: US
Publication date: 1927-02-22
Anticipated expiration: 1944-02-22

Description

Feb. 22 1927.

. 1,618,285 A. T. 'KAESLEY BLADE LASHING I Filed Sept. 12. 1925 2 Sheets-Sheet 1 [l5 A /H- 4 v i l fi l6 x i lfl WITNESSES:

ATTORNEY Feb. 22, 192?.

, 1,618,285 A. T. KASLEY BLADE LASHI NG Filed Sept 12. 1925 2 Sheets-Sheet 2 I 4 I l I l WITNESSES INVENTOR I BY C? ATTORNEY Patented. Feb. 22, 1927.

mairsa stares iaiazas rarest. car es.

, v ALEXANDER T. KAsLnY, or Moonn'rEmTsYLvAiirA, AssIeiioa T wns'rmenonsn ELECTRIC ailmnuracrunine coiviraiw, A CORPORATION or PENNSYLVANIA.

of a lashing means fortheblades which:

BllADE resume.

mamas filedSeptembei 12, 1925. 7 Serial No. 56,027.

My invention relates to elastic fluid tur-' bines, more. particularly to the bladin'g thereof, andhas for its object the provision shall be simple of design, easy of application and; which shall be effective to mini? mize vibrationoftheblading. I 1

Apparatus made-in accordance with my invention is illustrated in the accompanying drawings, forming a part of this specification, in whichFig. 1- is a fragmentary sectional view of a plurality of turbine blades having my improved lashing applied thereto; Fig. 2 is a view similar to Fig.1

showing a: modified ,form of my invention, Fig. 3 is a similar view showing a further modification of myinventioni i is a plan 'viewof a plurality ofblades having still another modification of my inventionapplied thereto; and Fig. 5 is a longitudinal sectional view of the structure shown in Fig. 4:. I y

, As iswellunderstood in the art to which my invention relates, turbine blades when subjected to strains incident to service are liable to vibrate and break dueto vibration. In order tominimize vibration, some form of bracing means is usually applied, extend ing along a blade :row and secured to each blade of a segment of blades bysoldering, brazing or otherwise. While such a form of lashingis effective to minimize vibration, considerable labor is involved in applying it i and, where the lashing is united to the blade by fusion of metal, it has beenfound in some instances to have a deleterious effect on the physical properties of theblades.

Furthermore, 'wlth lashing secured by whatever means to a series of blades, upon.

.expansion and contraction of the blading and blade carrying element, there IS an alternate stretching and crushing action between the blades and the lashing. This is due to the fact that radial 'expansion and contraction of the turbine, parts increases and decreases the distances between-adjacent blades in a row. The alternate stretch ing and crushing action between the blades and the lashing tends to fatigue. the metal thereof and ultimately 'lead to break-age in. many cases. 7 I

In accordance with my invent-ion, I'have devised a turbine blade lashing comprising members which arefeifective to dampen vi bration of the blading by frictional engage- ;ment therewith. In the case of moving blades, the frictional engagement is secured byproviding an element of the lashing of sufficientniass so that, when the turbine is operating; centrifugal force tends, to hold it in tight frictional engagement with a cooperating blade. In thecase of stationary blades, the unattached lashing'element is preferably made ofresilient' material. and is sprung, into engagement with its cooper- I ating blade With this form'of lashing, up-

on expansionand contraction of the turbine parts, the lashing members are free to compensate for changing distances between ad-. jacent blades by sliding at, the point of frictional engagement. At the same time the together by a relatively-thin neck element v13 The element- 13 is'made' oflesser'crosssection than theothe'r two elements in order of sufficient size so that the member 12 slides freely therein.

lVhen the lashing preferable'to provide a double row of lashing and to secure themembers 11 toalternate blades as shown. In this manner, each blade 10, in the process of manufacture, has attached'theretogone of'my improved lashing elements and is adapted to receive the ,meinher 12 at the lashing. element attached is applied as shown in' Fig. 1,;and having only one member 12, it IS.

to minimize the resistance to motive fluid to adjacent blades. In operation the member 12 is held in firm engagement with its associated blade 10 by reason of centrifugal force in the ease of moving blades.

Referring to Fig. 2 I show a form of my invention better adapted for stationary blades. The lashing here shown comprises an element 16 attached to a blade 17 in a. manner similar to that shown for the element 11 of Fig. 1. In this instance the lashing element is made of resilient material, is bifurcated and 'e'XteIidsto an adja cent blade Where it is provided with an enlarged portion l8 which is sprung into the blade and is engaged therewith by frictional contact due to the re si'liency of the material employed. As in the case of the-lashing illustrated in 1, it is preferable to apply theform shown in'Fig. 2 in two i-o'ws and secure the elements 16 to alternate blades.

, ;Referr ing now to Fig; 3 I shoiv another form of m y invention applicable to moving blades and which is permanently attached to only one blade of a segment of blades; The lashing here shown comprises an element 21 v similar to the elements 16 and 11 shown in the previous embodiments and secured to a moving blade 22. Connected to the element 21 by a series of elements of relatively small cross seetion }Z323 are a plurality of elements 24-424 similar to the elements 12 shown in 1 and Whieh engage With their asseciated blades by frictional contact induced by centrifugal force. In accordance with this modification of my in'vei'ition I may only apply one ow of l'ashiii'g, though it ivilli be ebvi'o'us u na pliirality of rows might be employed with equal advantage where required. a p

Referring to Figs. 4 and 5, I show a series of blades 26 having an outer and an inner series of l1oles,27+27. and 28 2 8 provided uremia Theliol'es 27 27 and 28-28 are elongated, having the greater dimension in the direction of ,1n6tive fluid flow. Inserted in the holes 27 in the alternate spaces b'etiveen adjacent blades in a roW are individual lashing membersComprising the

elements

29 and 31 fitting freely into the holes 2?27 and joined together by a member 32 iwlder than the holes 27 2j7. The member 32 be'ingwvid'er than the holes in the blades eerv'es to preserve 'the proper distance be tween the blades and holds the lashing members in properposition, In the other alte'i' natespaces bet'iveei'i blades in a row a series of similar lashing fl'iQll'lbQIS are inserted in lheditiles ZS-28 so that theinne'r and outerserie's are, applied in staggered relation.

, lvhenapplied to moving blades the form of lashing here shown engages with the bladesvvholly by friction induced by Centrifugal force. Y I

From the foregoing it will be apparent that I have invented an improved turbine While I have'shown'my invention in several forms, it Will be obvious to those skilled in the art that it is notso limited,-,but is susceptible of various other chan ges and modifications, Without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are ilnpbs'ed by the prior art or as are specifically set forth in the appended claims. i

lVhat I claim isi. g

1. A turbine blade lasl'iing comprising a member extending between adjaeentblades her with a bla 'e solely by friction.

2. A lashing for turbine bladeseomprising one member/adapted tobe seenr'edto a turbii'ie bl-ade, a second member, "means for iii a 'ron andneans for engagingsaid mem engaging said second member with anad .jacent bade by friction only, and a third member joining the first and 'secofn'dfmemr ing one member adapted to; be secured roe turbine blade, a second member movable relatively to an adjacent blade, means for ensaid second member with said 'adjacent blade by friction, and a thirdmeinber of relatively small cross see'ti'o'n'al area joining the first and second members f1. The combmation with a plurallty of turbine blades is a row havhrgholfes provided therein for the insertion of lashing memof lashing means for said blades ex tending'betweehyadjacent blades in a row, each of sald lashing members being movable relatively to at least one blade, and means for engaging each lashing member with said one blade by friction induced by centrifugal blades in a row comprising a member adapted to a turbine blade, a second inner and an outer series of holes provided in said blades for the insertion or lashing members, laslnngmenfbers 'sec'nred each to one blade 1n the inner and e or, series of holes in sta gered relation and means for engaging said lashing members with adjacent blades in aroi'v solely by friction.

7.111 a turbine, va row of moving blades having aligned holes provided therein for the insertion of lashing members, lashing members inserted in the holes and extending a a lashing for was blades comers-i between adjacent blades in a row, said lashmovable with respect to an adjacent blade, mg members being secured to one blade and and means for engaging the lashlng member having means for engaging with another with said adjacent blade by friction. 1 blade solely by friction due to centrifugal In testimony whereof, I have hereunto 5 force. subscribed my name this twenty-sixth day 8. In a turbine, arm of moving blades, a of August 1925. lashing member securedto one blade and ALEXANDER T. KASLEY.