US2517714A

US2517714A - Ship's propeller with blades adjustable during service

Info

Publication number: US2517714A
Application number: US532665A
Authority: US
Inventors: Roesch Fritz
Original assignee: Individual
Current assignee: Individual
Priority date: 1943-08-23
Filing date: 1944-04-25
Publication date: 1950-08-08
Anticipated expiration: 1967-08-08

Description

Aug. 8, 1950 F. ROESCH 2,517,714

SHIPS PROPELLER WITH BLADES ADJUSTABLE DURING SERVICE Filed April 25, 1944 2 sheets-sheet 1 BY /Ai ATTORN EY F. ROESCH SHIPS PROPELLER WITH BLADES ADJUSTABLE DURING SERVICE Aug. 8, 1950 2 Sheets-Sheet 2 Filed April 25, 1944 INVENTOR Fe/rz Pa-fc4 ATTORNEY Patented Aug. 8, 1950 `OFFICE snlrs PROPELLER WITH BLADES AnJUsTAnLE DURING SERVICE Fritz Roesch,` Lucerne, Switzerland Application April 25, 1944, Serial No. 532,665

6 Claims.

l The invention relates to a ships `propeller with blades adjustable during service.

It is known in water turbines to secure the moving blades tted in the hub by means of collars, these collars having a length in the axial direction of the turbine shaft which is greater than their breadth. The collars of each blade situated inside and outside of the hub, however, are of equal length, which gives rise to the disadvantage that the total angle `of adjustment `of the blades can only be comparatively small, since otherwise the ,outer collars which are elongated in an axial direction would require a comparatively large hub diameter in order that the outer edges of the collars should not project beyond the bearing surfaces when the blades are turned. The limitation to small angles of adjustment for the blades has inthe case of ships propellers the disadvantage that an adjustment of the blades is possi-ble for running ahead but not for running astern. Thus the known design of Support for the blades does not fulll `one of the main purposes for the use of variable pitch propellers on ships, namely the .simpliication and/or improvement of the propelling engine by the elimination of the necessity for reversingthe engine.

The invention therefore proposes that the blades should `be supported against the hub by means of plate-like bearing surfaces, the outer edges of the inner bearing surface of a blade being further distant from each other in the axial direction than in the direction transverse to this, but that the distance between thelouter edges of the outer bearing surface inthe` axiall direction should be `smaller than that between the outer edges of the inner bearing surface.

This offers the advantage that the smaller longitudinal extension` of the outer bearing surface makes it possible to have a smaller hub diameter in spite of the angle of adjustment being large, a :circumstance which isof decisive importance for the eiliclency ofl `marine propellers. i .145

Above all it will be advantageous 1if. the outer bearing surface of a blade is designed with a circular outer shape, for in this way not only can the sealing of a blade be simpliedbut the outer bearing surface :can also be arranged com pletely within the packing, which is of essential 4importance for faultless service. Only in this way can the fouling and damaging of the bearing ensured.

In `the drawings several embodiments of the invention are shown diagrammatically.

Figs. l and 2 show a longitudinal section and a composite View respectively of a propeller hub withsupporting plates designed in onepiece. The right half of Fig. 2 is a `top view of the device shown in Fig. l with the propeller blade and its retainer member removed. The lower left portion of Fig. 2 is a top view ofthe device shown in Fig. 1. The upper left portion of Fig. 2 is a top view of the device shown in Fig. 1 with the propeller blade and intermediary member removed from its inner bearing member.

Fig. 3 is a longitudinal sectional view of a modified propeller blade pitch changing mechanism according to the invention.

Fig. 4 shows a portion of a section of `themechanism shown in Fig. 3, taken along line IV of said figure. l

Fig.` 5 is a top View of the mechanism` shown in Figs. 3 and 4 with the propeller blade and intermediary member removed and part of the hub cut away. Y

Fig. 6 is a rear. view of the mechanism illustrated in Figs. 3 t`o5.

`in front of `this blade-carrying part.

The propeller with its hub 2 and its blades 3, the number of which is ordinarily from two to four, is attached to the propeller shaft I by means ofthetaperedshaft end 4 and the nut`5. The blades 3 can be adjusted during service.` In the hollow shaft I is provided the push rod 6 with the cross-piece 1 attached to it. The push rod is moved backwards and forwards in the axial rdirection by means of a device, operated by hand or by a servomotorand not shown in the drawing* The bearings 8 and` 9 provide parallel @guiding for one connecting rod I0 for each "blade 3, and this rod has a `pin Il which is surrounded by the slide block l2.

The

t suse mock l2 slides in the .groove I3 `provided in the vinner bearing member 26, and when the rod E or the connecting rod I0 is axially displaced, ybrings about a turning of the` member y 26 and thereby of blade 3 about the centerpi I4, p A. .a A

` The root portion of blade 3 is rotatably supported in the hub 2 Iby means of the inner and outer thrust bearing surfaces I5 and I5, which take the form of plates. The outer edges I'l and I8, that is the outer limits of the inner bearing surface I5 of a blade 3, are further distant from each other in the direction of the axis I9 than the edges, that is the corners 22 and ZI, in a direction transverse to this axis. The whole inner bearing surface. I5 thus has a--form which is elongated in the axial direction I9, while the breadth of it is shortened transverse to the axial direction I9, a circumstance which allows -.a smaller diameter of the hub 2 to be obtained than would be the case with a, circular inner bearing surface having a diameter equal to the outer dis tance Il, I8. Further, the distance-.vinv thel axial direction I9 between the outer edges 22 of the outer bearing surface I6 is considerablyjfor instance smaller than the distance-between the edges I'I and I8 of the inner bearing surface I 5.

This elongatedv inner support 'I5 isn `entirely adapted" tothe forces, presenting themselves in the'blade, since the bearing' surface' isk greater in the directioniat right angles' tothe plane ofthe.. blade thanlin thedirection transverseto this. The thrust. resulting from "the ."ow along the blade is in fact almost at right angles to .the sur- 4`face plane ofthe' blade. .The elongatedform of the.' inner. bearingv surf ace also` provides a. wide base iorthe supporting surface, and thecentres of gravity of the forward and aftsegmentalparts of the bearing surfaceI can be at almost.. any distance'from each other. as 'this 'distance can' be great even whenpthe width orithe surface I5is small and thus the diameter ofA the hub 2 issmall, a situation which `contrasts with thatpresenting itself in 'the case of. a circular inner bearing surface.

As withV plate bearings the inner bearing-surface also' has to. take the considerable centrifugal forces, the elongated form ottheinnerbearing surface enablesv the area of the surfaceincm.2 tobe chosen as great as desired evenwhen the diameter of' the hub' is smalland-. .thus enables .the specic `loading..to..be`..keptsmall, above all becauselthearea of the outer .bearingsuriace .can be kept small" in spite of having'afsmall specific. loading.

It would also be possible for.the..o.uter.bearing ,surface I6l to be, like the inner bearing'surface I5, longer in. the axial 'direction I Qthanin .the direc- .tion transverse to this. In. Figs. 1 and?. theouter bearing surface I6,however.has1a.circular.outer .form. This has theadvantagethatthe ,packing .can ,be arranged in a groove23=..around..the.out side .of the outerlbearingisurface:IS, :and .the sealing towards theoutside. can.-.th11s fbe v.etlected .in a simple and. adequate manner. YIitheouter ...bearing surfaced@` .were..also.-elongated, .at least the outer sealingsurfacecould becircular.

`'.lheblade 3 .has a circular rootrlange 24,.,which `is connected. by the. bolts2I.withthe outerlsupportingl plate '25 .and the. innersupporting 4plate 25. While the outer plate 25..is.of circular design, the inner.` plate 2E has an..elongated tormto-correspond tothe. design .-of.the :bearing surface-I5 and is. centred on. the outerplate.25cby.means:of the projection 28.

" The'two platesl 25.fand-2I.are.supportedqagainst the elongated .piece 29. The .form of this-.can--be seen from Fig. 2. The lower left-handenarter .of the drawing shows the hub. 2.from..-the..outside with the blade 3 in place, the upper left-hand .quarter .shows .the hub.. without .ther blade ,-3q and v.;

4 without the upper supporting plate 25, so that the piece 29 is visible with the groove 23. The righthand half of Fig. 2 shows the hub 2 Without the piece 29 and in particular the forward end of the inner bearing plate 25, the aft end of which has the same design.

The piece '29 is attached by means of the bolts 30 to the hub 2 and is sealed by means of the packing Y-3I i (Fig. l). Thus the blades 3, with 'l2 their-.hub portions composed ofpieces E5, 26, and

supporting shell plate 29, can be introduced into the shell of hub 2 as one unit and bolted to it.

This offers the advantage that the bearing surfaces I5 and Il on the piece 29 can be machined r' "in a simple manner and easily fitted to the bear- .ingsurfacesA I5 and I6 of the

plates

26 and 25.

Towards the rear the hub 2 is closed in the usual 'mannerby means of a hood 32 consisting of two parts.

While in Figs. l and 2 the hub 2 is attached to the shaft Iby means of the tapered end 4, in Fig. 3 lthe shaft I isprovided witha flange 33 and attached to theend wall` of the hub '36 by lbolts 34 distributed around. thecircumference of ff "the 'ange"33, whilel it is centred by means of. a projecting piece. The bladesl are provided with .a 4circular root 3l which. is centred on the outer supportingr platelii and attached tolit by. means of the studbolts 39 andthe nuts`4.

.Theinner supporting lplate. isdesigned in sevn eral parts. `Wh`ile thepartslllv and 44 arerprovided with.' the'` bearing. surfaces 4 I. and 42, the middlepart 45 of 'the inner supporting plate has .a pin .46 which.' is tte'd. inthe bearing `Flor eachpblade 3 asimilar bearing.4l' is present, .and these are all connected to theend walljioi 'the `hub`35 by means of the sleeve '48. ,Both the .bearing surfaceslil an'df42 of the innerplate43 'to145 andalso/the'bearing suriaces'49'of the outer plate .38 are ,of tapered ,design,` and 4the outer plate '38 vis Vsealed Aby .means [of [the packing" 50.

The.' .tapered design of .the bearingsurfaces 4I, '42, '49 Ymakes' it,v possible 'for the layer ci .metal .of thel hub between the blades tor be surricient even .'When a large' number of.y blades isemployed and above`all`for 'the diameter of the hub.. to be reduced in thatboththe plates. 38, 43, 44 andalso the hub, piece. 3S .are sullicientlythickat theplace wherethe bearing

surfaces 4I

42,48 begimwhile .the thickness.of.these .piecesat their .endscan be small.

The .design of lthe .-supporting,..plate in several. parts .enablesY it to. be v -zrectedwithout a specially inserted.. supportingpiece,v such v,asethe piece' l29 .inl Figs.. 1 .and 2,. asfthe, parts` 43. ande44 are, passed through the -circularopeningI` 5I individuallyand thepart '45 is afterwards placed 'between them, `whereupon all three.are cononected'to the `Vouter 'plateLSB by means of the stud l'bolts 39.

' 'An-adjustingshaft52 isprovided foradjusting tapered #end Land a rnut,'-the lspider"'53. -This spider has for each blade a slide block54, this i :being'designed::ir'twoslpartsi and enclosing the fui-nner'supporting platef43---45-v Y By operating. the blades 3 'rby-^means ofzan1ad Hiustingshaft .and-.-a.spider, it is possible toconnect vthesleeve: 43.- an-dirthe bearingfllv rigidlyv to .stays 56 (Fig. .4) .which/form continuous longitudinalavallsthrough the.. .-hub. Ira connecting rod With parallel guiding, such as the rodrI 0.. in

's Figs. 1 and 2, or a known form of link were used for adjusting the blades 3, the stays 56 would have to be omitted. If a link were employed, the inner plate 43 to 45 would have to be provided with a l pin in place of the slideblock |2 in Fig. 2, while the cross-piece 1 in Fig. 1 would have to have a pin or bolt for each blade 3. l .l

A further reduction on the maximum diameter of the

hub

2 or 36 can be obtained by letting the lateral edges 51 and 58 of an inner plate, such as the plate 26 in Figs. 1 and 2 or the

parts

43 and 44 in Figs. 3 and 5, run parallel not to each other but to the axis I9 of the hub, when the blades 3 are in one or other of the end positions. The spider is protected by the hood 5S.

This special design of the lateral edges 51, 58 of the bearing surfaces `I5 or 4| `and 42a design similar to the form of a bricklayers trowel, offers the advantage that with a small hub diameter a large angle of adjustment for the blades 3 is possible. Thus, for instance the angle of adjustment in known rotors of water turbinesA is only 15 at a hub diameter of 3.5 times the shaft diameter or at a ratio of the hub diameter to the rotor diameter of 0.35, While in Figs. 1 and 2 the total angle 2a amounts to 60 `at a diameter ofthe hub 2 equal to 2.54. times the diameter of the shaft I, and the angle of adjustment is thus considerably larger in spite of the smaller hub.`

By this means it is possible for the blades 3 to be adjusted both for running ahead and running astern.

The tapered design of the bearing surface leads to a still smaller hub diameter of 2.30 times the diameter of the shaft in Figs. 3 to 6. The angle is 50, but if the blades 3 are adjusted by means of the push rod 6, as in Fig. 1, instead of by an adjusting shaft 52, it might be just as large as the angle 2X@ in Fig. 2. The ratio of the diameter of the propeller to the` diameter of the

hub

2 or 36 in the plane of the blades 3`;amounts to 0.25 at the most with a propeller as `in Figs. 1 and 2, and with a propeller as'inFigs. 3 to 6 to 0.23 or less.

The angle y in Fig. 6 shows the turning of the adjusting shaft 52 when the blades 3 areadjusted through the angle The cross-section VI-VI in Fig. 3 and all other cross-sections parallel to it through the hub 36 are circular in shape, while thelongitudinal section of the hub 36 passing through the axis I9 has an elliptical form, so that the hub 36 is designed as an ellipsoid and has the advantage of being adapted to the elongated formlof the inner supporting plate while it is also favourable for the flow of water over the hub.

The propeller |I in Fig. 7, with two or more blades 02 which are adjustable during service. has part |03 which carries the blades |02 and which is closed towards the rear by a protective hood |04. The blade-carrying part |03 has on each side of the blades |02 an end wall |05 and |06 connected to the parts supporting the blades. These two end Walls are both attached to the propeller shaft |01 and are connected by the sleeve |08 which surrounds the shaft' |01 and which has a tapered bore. The adjustment of the blades |02 is done by means of the linkage parts arranged inside the hub, i. e. by the links 4, which are attached at their aft end to the crosspiece I I which is in its turn attached to the push rod ||6. The push rod I |B leads to an auxiliary device for adjusting the blades |02 situated in the body of the ship and not shown in the drawing. The end wall |06 can be attached to the sleeve I08 and detachably bolted to the outer wall III. The blades I 02 are provided with an inner `supporting plate |22 and an outer supportingplate |23, both of which rest on the bearing ring |24. l

For the purpose of attaching the propeller. |0| to the tapered end I|1 of the propeller shaft |01, the part |03 is provided at its forward end with a thread |29. The propeller shaft |01 has a thread |30, which either has a different pitch from the thread I 20 or differs from it in that, for instance, one of the threads is left-handed while the other is right-handed. The hub is attached by means f of the nut |3|. The key I 20 is provided to secure the parts against relative turning The propeller shaft I 61 may also, in accordance with a known arrangement, .have a thread on which a nut is screwed which presses the sleeve |08 rmly upon the tapered shaft end I I1.

The support arrangement of theblades `in Fig. 8 is the same as in Figs. 1 and 2, the blade carrying part |03 of the hub is,` as in Fig.` '7..designed l in one piece. The part |34 of the lower supporting plate is provided with a lever arm |58, which is designed at its forward end as a ball and |58, and |6| serving for the adjustment of the blades |02 are arranged so as tobe watertight inside the hub I0 I. i

The adjustment of the blades |62` is effected by turning the sleeve |62, `which is` provided at its l forward end with a steep-pitch threadfl. The

When the lever |69 is adjusted, the sleeve |61 is pushed backwards in an axial direction and, on account of the steep-pitch thread |66 the sleeve |62 and with it the spider I6I are turned A4relative to the propeller shaft lll. The slide 'blocks i Blturn'about the*propellershaftr l 0l `and :carry the 'ball "jointf i159' withftliem, so that the "iblades"\f02-are"turned about their axis.

"The'threadjlli ca-n'A have f a' pitch of such a type"that"itiis-= self=locking i 'and -any turning of lvtrie-sleeve162^urideintheinfluence of a torque fat'zthebiades 102 -is obviated. The'advantage or" *tnisidesign lconsists'-inlthat the ldiameter of the hubis'small since the shaftdoesnot need to have iiabore and the'. same ycon'iparatively smalrdimen- 'r'sons canibef'keptas 4are employed with fixed ititulados. i' This advantage''makesitselfA very notice-- i'ablyi-felt'in'particular with vpropelle: diameters l",b'elow"1":5or even`r2-n1etres The-sleeve 'H52 serves :at theY same time as-a protection anda support for theshaft 101. -`Itfissu'flicient for the sleeve -T62'to^1ie":`lose against the lpropeller shaft i 0'! in 'therneighbourhood yofthe sterrf tube bearing H4 Yandrat its Iends,V While -it Vmay have a somewhat Widen -bore xbetween these points.

f 1.`fIn'-' afvariable pitch propellerf a hub member, av propeller blade haVinga'blade root portion rotat'ably-mOuntednrsaid hub member; said blade iroot 'Aport/ioncomprising twol thrustbearings ax- |`iil'ly spacedontheblade axis; the `thrust bearing closer to4 the-=propel1er laids' being adapted to receive the thrust acting in thedirectionaway from the* propellerA74 axis andi having yafft'nrustfbearing "portion extending' radially -ofthefblade axis-and projecting lbeyond :the other thrust bearing vand being" tapered as itfexterids` radially out.

2." In .avariabieipitoh propeller; a hub -member, I'fa'propeller"bladehealing-213blade root portion rotatably mounted insaid hub member, said blade f-root portionfcomprising two thrust bearingsnaxially'spaced on'the `blade axis, the thrust. bearing :closertol the propeller axis -beingfadapted tore- Aceive the `thrust acting inthe :'directionaway from'the `propeller and being composed of a plu- 'rality' ofv individual "thrust: bearing: members,` at least one of said members extending radially'of theblade'axisbeyondthe other thrust bearing. v"3."-Ina variable-pitch propeller, ahub member,

. `apropeller-blade having'- a blade root portion rotatably mounted in .said v'hub member, said blade `root, portion comprising twoA 'thrust `bearings axially spaced: on the 'blade axis,i.the% fthru'st bearing closer tothepropeller axis being-adapted to -receve the thrust acting in the direction away from the propeller 'axis and `having ltwo diametrioally "opposed portions extending radially of the blade axis and'beyondfthe other thrust bearing and be- Ying' tapered in'adirection parallel: to the rotation axis Vof't'hepropeller as they extend out.

fially kspaceclvon the blade axis, thesthrustbearing 'closer' to'thepropeller axis being adaptedto'receive the thrust actingin the direction away from f the propeller-axis 'aridi comprising-anannu-larpor- 'tionandrar portion exteridingfrom `said lannular portionand"radially-of the blade aXisa-rid beyond 1the other fthrustl bearing, and a' pitch varying mechanism radially-1 Aslidaloly connected-With said *annular portion.

5. In a variable pitch propellena hubmember,

af lpropeller-'blade'fhailinga blade root portion@ rotatablytmounted inisaidi l'i-ubA membeisaidv blade root portionf comprising*two- 'thrust bearings-axiallyfspaced on fthe* blade*axisthe'thrust bearing EAcloser to thegpropeller axisnaving la 'projecting portioneexteriding radially'df` the blade axisfand i beyond the `-other thrustbearing. and pin means disposed coaxiallyavithsaid'rootportion and rotatably interconnecting f :said 'fhub member i and 'the' thrust bearing which is closer to' vthefpropeller taxis thanfthe A'otherbearing.

a variableipitchpropeller;the ycombina- 4tion Yof ai'iillb "men'lber,v 'aisuppo'rtingwsliell plate havingf a :marginal =portion=removab1yrsecuredto *thri-i'sbearing r`-outsideffof "and adjacent to: said shell 'plate, fa ':bla`de root portion irotatably "mounted inI said shell.' plate; :and .a bearing imeans tending radially ffftheblade axis farther than said thrust' .bearing rbut'finot asf :aryf'as the Aanarginal portion off-saidsshelllplate FRITZ ROESCH.

.' REFERENGES-C1TED *The `following references v'are of i record. 'in'.the

rNumber *Intieme Date :18015685 Perkins Oct. 0,f-1905 :821,534 f'Perkins May 22,?,1-906 1,1335222 :Bevis Mar; 23,1915 1,510,436 Englesson fJSeptiBG; 1924 2,002,735 Fuchs May 28,:1935 i `2,055,196 fl'uchs Sept; 22,11936 42,246,539 eRu'thset al.., .rlune24, 194:1 2,255,920 Englesson, ".Sep-t. 116,? 1941 FOREIGN PATENTS `Number Country Date 14,232 :TNorway Decy2,` 1894-. 41,781 .Gr-eatBri'tain *Mar. 10,1892 @4,789 Great Britain 1905 23;996 :SWeden -.Oot.i26,1'906 11235 689 Vf Austria July-,15,1908 62,291 :Sweden .Sept.:25, 1.924 53343549 Germany -June 22,1920 1375,43() f France nMay 14, 1907 400,268 iFrance fli/layiZI,E 1909 609;006 f Germany Nov; 30,#1933