US1632543A - Steamship-driving mechanism - Google Patents

Description

June 14, 1927. "1632 j A. FLETCHER, JR., ET AL '543' .STEAMSHIP DRIVINGMECHANISM i Filed Dec. 5. 1921 Us sheets-sheet 1 June 14 1927. 632 54 A. FLETCHER, JR, ET AL 3 STEAMSHIP DRIVING MECHANISM F led Bed. 5, 1921 r a Shaets-Sheer 2 June 14,1927.

A. FLETCHER. JR., ET AL STEAMSHIP DRIVING MECHANISM Fil ed Dec. 1921 s Sheets-Sheet 3 W w! M Elm/W1 bot S.

, Patented June 14', 1927. I r i V 7 -10 turbinepropelled steamship; 'ln this branch} bine on tiu'bines is reduced through the me;

the douhleireduction type to the-"relatively im mwmvmtmama 'Applieation'meq Dccc-iu be 5; 1321. seri l No. 519,898. I

'lhekpresent inventionwvrel ates to gearing ffilf-iStefilllSililJb and ino re specially to amen; structien gfoi increasing the life oi certain typcs'o'i toothed gearii g'i J "5 Oiie-ot the important-fields for toothed! geairin'g is' theutilizati'oi'i I oii' such gears for speed: reduction. One service herespeed recluctien isv accomplished by highly de.

5 velope l types ofteothed geaning is the stea ng that} such pinion may reeeiVe"tiVenty=five' times -01 more-as n'iuch' Wear as 'the 'Cor're-fi spending gear wheeh Theref0re;=thepiiiioh geai w l-ieel f Itfis the pia'otieeinthiShrtFto provide helical teeth forthis type of gearing} iii -(1e v to properly transmit-the --1oadfend-Fat I the san e time avoid excessive end-{thrust and Vibration and other difficulties 'w-hieh are lihbleto attend straight teeth! A f'lhe pi actiee; heretofore sin the art has been to 1 min the K train of gears until the pinions-are wern out and t'hn lay up the ship unti1- the gearing CallbQ -diSHlBJIIHGQL and i1eW+ piiiion's'wsub stituted and -also other woni out parts. This practice is expensive and it is also-dangerous because often times; pinions --are*-run.:-w1*1en they are liable to bleak doiv11j-at -seai F urthern'iose, after the 'g'ear fteeth have *beeli Worn to the extentthat t11e-f2es ot the teeth 5 no longer are of correctz contou1;-*thewean ineieases very rapidly ar d 'the-lifekof su-eh teeth cannot be, fflcG'tllffi-tely pi edietefl and they are liable to break unexpectedly: 25: vilcie pairshofwiverylarge/gears connectedidie 'l1 =1e-present invention solves the adifii'cul rectlyto .a lpi opellemshafti and pairs ofirelatles of thezknown art greatlyextehtiihg 01 tilvely small".pinions; connected: 'eithe hreat- PI'OLQngingth efig t e lifeu f ui z 1yt0-t111$1131t$ Of-th-t1lfbi11$-ili thewsingle i i-such maii'ner that much 10I1-g61 Wear, of a reduetiom typeiorlli f the -d'oubleh reductioii i a secoiid setaofi gearing which may; comprise another) pair :of ire1atively-;1awe gearsganct a, icoi'iesponding pair. of: nelagtiveiy small p'iniona with @the final and jISIlliLllSb 1 of -.i g;.t1 wei-y high speed of the "w diuin of large expensive g ear-ing sets-ofthe single reduction typeand lD ITIEIIiy-CQQSBS ot s10 W speed required by, a screw propellem This type of mechanism is necessarily vei y strong and very heavy abecauseptthe horse power Whichis ce1it1 a1ized= in and} transe- 20v mitted to the propeller shaftx It is common practice to am ange agphirality of' turbines to drive single pi opellei shaft through the inteririediLof suehki'ecluction :geari-ngm In this typeeof construction iti is; usual to pro-v replacement- One embodimentmf the- -pres'- en-t inver tion comprises =GOI1StI 110i3ii1gthe J teeth i'off thelarge' gears and: a1sotheteeth 1 of the pinions so that anypinion and sha-ft singleset of geayscanbeobtaiiied ithout- I pair "of pi-nion's connected directly to the tunthine shafts." Ifiboth types ofmechahismzthe train 1 of gearsis; run a fiery-large 'peneentagegi of: the time in ox edirectionbecause the V steamshipamoves' Lfor'ward nearly a-ll v of {then 7 tinielaiich'goes asternon1y1na=sma1iwpartof: 40

i the time. 1' viewgiof the) substantially: pen;

' tinuouseduty imposed upon-theforward: side;

oftthe geaeteethiitsfollows thattthe-forw vai d r v side: of the gear; teeth aisaavornzzoutgwhen the a backing on ,;ster1i lsidei' ofitheteeth sis@substantially unwo'rnm The Lwean..;;on.;the for Ward 1;; side M is. a accentuated v by: sliding and grinding, of .thej c0ntacting ages- L teeth? I due to? vibi: ation; of; the-ship. while; the nteethxai e transmitting the heavy load; Thiswweanmay also be accentuated "by lack of .e'fiieient :lubri cation; accumulatiom of Ldi f't i and grit; and v by y-lniamy 0ther-1 eauseshvhich 'imay shorten the life 0%: the gearsaa The, rat owbetween 4a a piiiieu sand itsicor'responding gear: may: Joe

on iai ge gean may be 'removect {from its hearings aii in its bearings: and the teeth on I the-{gears and' pinions will continue tomesh properly WithQHi? ehanging thea desired dii i ectib i of rotation of the: trair oi: gears and 'propellep shafting. When thew-pinion- -is i eversed-fithe back 3 fades-of the teeth ion the =pini01 become the forward drlvingifaces and in viewj-of the lac-i wean: err-such haek faces, the gear not change the'fdesired directionaof rotatioii sosithati (the direction of v m'oyement being transmitted ith 'ough the vgea'r set irem the driving shaft" to fi1ia1 driv'en shaft is "the same asit WaSzbfeFe the change-is' madefi v .Thepresent invention also contemplates certain consti uctions i11 the system of i'e- 'as greataas tWenty;fivee-0ramoirento tone.1 01 du-ction gear ngwherebyitiis possibletowe verse the faces of any of the gears of a train of gears, thereby still further increasing the life of the gear set.

After having described the present invention in general terms, it may be stated that the principal object of this invention is the apparatus for prolonging the life of gear sets and the like by means of congruous tooth shapes.

Another object of the present invention is the mechanical design of a reduction gear set for turbine Ship propulsion and the transmitting of power through gearing wherein the gearing is so constructed that the stern or reversed faces of the gear teeth may be arranged to comprise the driving faces of the gears by reversing certain elements in the gearing.

A still further and more specific object of the present invention is that improvement in reduction gearing comprising pairs of gear members provided with helical gear teeth and with the angle of inclination of any portion of a tooth upon one gear having a congruous counterpart in a corresponding tooth on a companion gear.

Other and further objects of the present invention will in part be obvious and will in part be pointed out hereinafter in the specification following by reference to the accompanying drawings forming a part of this application and in which like parts are indicated by like characters throughout the several figures thereof.

Realizing that the present invention may be embodied in constructions other than those herein illustrated, and described it is desired that the disclosure herewith shall be considered as illustrative and not in the limiting sense, and that the scope of the claims shall be as broad as the language thereof when interpreted on the disclosure will admit.

Fig. l is a plane view showing the intermediate and driven gears of a double reduction gear unit adapted for use with a steamship turbine;

Figure 2 is a diagrammatic plan view showing the pinions and intermediate gears of the device shown in Figure 1;

Figure 3 is a diagrammatic detail illustrating the relation of parts;

Figure 4 is a view similar to Figure 3 showing one gear member reversed;

Figure 5 is a diagrammatic view of an elevation of Figure 3 looking in the direc tion of the arrow X and showing the stern faces of the gear teeth as shaded;

Figure 6 illustrates certain of the parts in Figure 5 when reversed in position;

Figure 7 is a detail sectional view showing the construction of the large gear shown in F ig. 1.

Referring to the drawings and more specially to Figures 1 and 2 which more or less diagrammatically illustrate a double reduction gear unit which has been chosen as illustrative of the present invention. in this chosen illustration two turbines are illustrated comprising a high pressure turbine 1 and a low pressure turbine 2 which are mounted in suitable casings and bed plates to be set in accordance with engineering practice. Each of these turbines are provided with couplings at which connect the turbines with the shafts 5 of the first stage reduction gear pinions (3 and T. The reduction gear pinions 6 mesh with large gears 8 mounted on the shaft 9 and the reduction pinions 7 driven by the low pressure turbine Q mesh with large gears 10 on the shaft 11. The shaft 5) carries second stage reduction pinions 12 and the shaft 11 similarly carries second stage reduction pinions 14. These reduction pinions 12 and 14 mesh with the main gears 15 which are securely mounted upon the main shaft 16 that isadapted to be connected to the propeller shaft (not shown) by means of a coupler 17. The construction described, so far as general arrangement and organization is concerned, is common practice.

The present invention comprises more specially the arrangement of the teeth, shafts, bearings and couplings in reversed symmetry. Preferably the teeth are arranged in such manner that a central plane cutting a gear at right angles to its axis will divide the gear in such manner that when either side is reversed and placed in position of the adjoining side, the angle and shape of the teeth on the replaced side will be exactly the same as the angle and shape of the teeth of the original side of the gear. Preferably this arrangement is carried out through the entire set of gears so that the shape and size of the gear teeth on the gearing lying on one side of the central plane cutting the axes of the set or unit will be congruous to the shape and size of the gear teeth on the other side of the plane. This may be carried out by providing the gears with teeth arranged as shown in Figure 1 wherein each main gear 15 is divided on its tooth face to comprise teeth 18 inclined clockwise on one spiral. and teeth 19 inclined counter-cloclm'ise on the opposite spiral. The. same arrangen'lent is carried out as to the pinions l2 and I4- and also as to the large gears 8 and 9.

Reference will now be made to Figures 3 and 4; wherein the gear teeth are shown diagramn'latically and the teeth on one half of the gear set are shown in full lines while the teeth on the other half of the gear set are shown in dotted lines, in order to distinguish the teeth so that they may be followed by explanation when the reversal has been made. The set of teeth A are shown in full lines and the set of teeth B are shown 11; aoai lines; In "ri -urea "the ama 9 has been reversed, that is; itzhas beenz turnedq end for, end, so: that the pinion 13 is now in engagei'nent with :the teeth; of the large gear AF-andthe; pinion A}? isin engagement w th: the teeth of the large gear-r Theefl'ecti offl-this reversaliofIt'henshaft 9 is shownialso, in: Figures 5 audit. r ilnhhgure 5, wln'chgis a diagrammaticend view"offlf 'gure 3, the;

stern faces on the several gears are shown in. shaded lines. By stern faces isineant the.

side of thefaces of the teeth which; carry,

the load 'wih'euthe steameris' going astern v and consequ-entlytheshadediportions of the teeth represent those parts whichreceive the least wear in the normal operation ofthe gear unit. v a I ReferringtoFigure 5 that illustrates an end view of Figure 3 looking in the direction of the arrow X, and which shows the 'arrangement before reversal, it will be noted that the inion B is in ei'wa 'ement with the main gear B and that thefirst reduction gear 'B. is in engagement with the large reduction igear' B Referring now to Fig ure 6, wlnch represents the end view of Figured looking in the direction of the arrow Y, and which shows the parts after reversal, lt wlll be noted the second reduction gear A j'is now 1n engagement With main gear B and the first gear A lsin en-,

gagement with the large gear A It will now be noted that, the shaded portions of the teeth which were the stern sides of the teeth have now become the driving side or forward side of the teeth on the gears, excepting the main gear 'B iwhich is so large that the, wear thereon is very small, and it need notbe reversed until several pinions -.-have been worn out.

It ]S to heunderstood'that where a con- "'nection is required on the end ofa shaft which is to be reversed a construction must be provided on both ends of the shaft in order to permit aconnectionto be made, as r for example the taper and key way 20 on the ends of the shafts 5 sothat proper consection can be madewith the couplers 4 when the shafts 5 -are reversed. I a

F gure 7 WlllOh illus- Referring now to trates a construction permitting'the reversal of the main gears without TQVGI'SlIlg: the main shaft 16, the gear frame G isprovidedwith seat faces21 and22 which are slightly taand 25 are adaptedto be held by means of" stub screws 26 that" are screw threaded into the body 1 27 and-28 on the rings 24 and 25.

place.

vpered and onwhi'ch main gear teeth rings 24 C and extend through'the flanges stub screws clamp the gear teeth rings verytightly upon the gear wheel frame so that the gear teeth rings are very rigidlyv held in. Suitable keys one of which is shown" at 30 are adapt-ed to interlock each of the gear teeth rings and the body so that the These with a propeller shaft; a pair of intermediate shaftsn' each of said shafts being symmetrical about a plane perpendicular to the construction it airline evidentith'at the transmitted, are necessarily helicalfgears.

By tl'iis' arran ement it will appear that tbe lite o'fa gear et ism-earlyincreased. I

, 'lhe present in venton" is p rticularl useful in. overcdining vibration due to. wear in the gearing. The operators of steam turbine parts are very securely unitedlfl By this 3 plants locate difficulties by sound .and'when r the gears wear so that vibration becomes excessive the effect on the morale of the operatorsis very depressing becauseit destroys the elementqon which they depend for safety,'

by finding trouble'before it becomes disas- I trous. Furthermore this invention prov des",

for therenewed relation being accomplished by merely reversing symmetrical interfitted parts, so that the renewal maybe made at,

sea or elsewhere with no special machinery required other thanjthat neededto handle the heavy parts.

lilaving thus described ourinvention, what we claim 18:. v I

1. Driving mechanism for steamships A comprising a large driven gear having teeth 1n reversed symmetry about a plane perpendicular to the mid pomtof its axisfand constructed to p'ermitready reversal to'change the trailing faces of the teeth toforward.

faces an intermediate shaft, symmetrical: about ts mid Ipomt; ntermediate gear means mounted; centrally 'onsaid intermediate? shaft, the teeth of I said intermediate gearmeans being in reversed. symmetry about a plane perpendicular to the midpoint ofthe int-ermediate'shaft to permit the inter-- mediate gear to be reversedby reversing the intermediate shaft in its bearings; a pinion shaft symmetrical about a plane perpendlcular'to its mid point; and aplnion mounted centrally on said shaft,-said pinion having its teeth in reversed symmetry about a plane perpendicular to the mid point of theshaft to permit the pinion to be reversed of all gear elements of the series whereby when teethbecome wornall of the gear elements may be reversed tochange all of the trailing faces into forward faces.

2.;A power plant for steamships comprising a large gear adapted to be connected mid point of the shaftyintermediate gear means mounted centrally on said intermedi ate shafts and operative to transmit power 11'5 by ref vet-sing the pinion shaft in itsbearing;said

construction permitting the ready reversal" i to the large gear, each of said intermediate gear means having teeth in reversed symmetry about a plane perpendicular to the mid point of its shaft whereby when the intermediate gear teeth become worn the intermediate shafts may be readily reversed in their bearings to cause the trailing faces of the intermediate gear teeth to become forward faces; a pair of pinion shafts, each symmetrical about a plane perpendicular to its mid point and having both ends formed for attachment to the same coupler; a pair of steam turbines, one coupled to each of said pinion shafts, and pinions mounted centrally of the pinion shafts, each of the pinions having teeth in reversed symmetry about a plane perpendicular to the mid point of the pinion shaft whereby when the pinion teeth become Worn, the pinion shafts may be readily uncoupled from the turbines and reversed in their bearings to cause the trailing faces of the pinion teeth to become forward faces.

ANDREW FLETCHER, JR. JAMES A. CAPSTAFF.

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