Note: Descriptions are shown in the official language in which they were submitted.
21414S5
lf~
Do~cription
PAIR OF CONVEYOR WO~S FOR ~OTARY PosITIvE-DIspLAcE~NT
PUMPS
Tho invontio~ rol~te~ to H palr of convcyor ~cre~s for rotsting po-
~itive-dieplaceme~t pump~, tho conveyor ~cre~e of which, in tho form
of rotor and co~tr~-rotor, rotate co~t~ctl~3 i~ th~ bore ~nd in the
fl~ka at the ~mo npeed (Jcr~ opindle pu~pa), form lonJ gapc bot~ecn
thom ~nd b~ve the ~sm~ throad dopth~, the ~me number of threads ~nd
flcn~ profiloJ ~ich ar~ sy~atrical on both ~ide~ and which ~ith
ro~rd to their pitch each conci~t of 8 tooth ~o po~i~ioned bolow
thu fl~nk p~ofil~ ro~orcinq point ~d A tooth ~ud po~itionod ~bove
thic fl~k profil~ rever~ing po~nt.
With ccro~ ~pi~dl- pu~p~ it i~ kno~n to provide the rot~tin~ conveying
elem~ec, c~ rotor8, ~ith ccrow-4haped profil~ which sre ~ubjec~
to tho laws of a goar tooth ayotom, b~t are not used in the firat
pl~co to tr~numi~ forco but to seal off the couveyiu~ chamber b~ween
tho ouctlon a~d precaure chambors. With the ~o-callod ext~rn~l beqri~g
~cr~ Jpindl~ pump~ th~ rotor~ rot~te cont~ctleffff in the ~ore and iLI
tho flHnkH and aro, thorofore, suitable for pumping non-lubricating,
viscou~ madis, whic~ ofte~ co~tai~ P~r~iclos o~ dirt ~nd ~olid~.
Tho volum~tric and the overall efficiency are in~luencod m~i~ly b~ th~
vi~co~lty of thH ConvHying medium snd dotrimontal gapc, whoro~s tho
21 ~1~S5
.~
presaure hoad i~ lnfluorlc~d b~ thc di~t~c- bet~een beari~ga, the
la~gth o~ the rotor, the pitch of the rotor, it~ diumetor ~rld tho hub
r~t~o NU ~ taoth bQ~e diamet~r ; tooth he~d di~eter).
I~ pri~ciple, ~ith th~ rotoro a d1ffer~tiat1o~ i~ ~ade bat~-o~ the
circumfero~tial gap ( thi~ i~ rho gap bet~ffn the rot~r ond the sur-
rou~ding rotor boro~, thc ba~o gap ~ t~iJ io the gap betweon tho out-
~ld~ di~otor of the on~ rotor ~nd the root circle di~ter of thq
oth~r roto~) and th~ gap~ betwe~ th~ flunk profile~ of the rotors
~han tho rotorff ~sh. With rc~ard to the flank gap ~ dif f~rcntiation
ln m~do bet~oen a gap that mu~t b~ pre-~et f~r the r~quirod coutac~-
froo runni~g And a profil- dope~dont g~p th~t occur~ du~ to th~ l~w.q
o~ ~ ~eQr tooth uy~tem. T~is prof ilc d-pe~dent lo~ g~p formb the
~ubj~ct of th~ pre~c~t i~vention.
lf ~t~ non-lubrlcatlng m~iA to be conveyed COIIt~ Y~ p~rt1cleY.
tho ref lux th~t OCCUrD due to tho counter-pre~ure c~u~e~ t wo~r
th~ough ~11 pl~ys; a~ a rcrult thoreof the pluys bec~e greater ~o
th~t ~lr~dy nftor ~ briof opersti~g period the cffective conveying
f10w ie rcducod. In pr~cticc thia pro~lcm i8 counter~cted either by
sa~r~l cloced ch~bero of th~ rotor ~rr~ng~d bohin~ o~o anothor, l.o~
by i~crea~ng ~ho ~u~bcr of ch~ber~, or by ~ ~if~erent ~pe~d o the
contr~-rotar The fir-t oolution cau~e~ ~ le~th~i~y of th~ rocor ~nd
ccordingl~ a Lar~o al~tance bet~een b~rlng~ ~nd a limit~ion of cho
convoying pr~snure due to th~ groa~cr d~1ection. Wlth t~e ~econd ~o-
1ution ltor~iY~ t~c rotors hsvc ~ d1ffcrer~t numb~r of thre~da ~d
~ccordingly diffcr~nt ou~cdo, duo to which ohortenod filli~g tlme~ and
2 i ~l~5~
.
oopoci~lly ~ith hiqh~r vlscooitieo 8 comploto filling of tho ch~mber
aro provonted. A furthcr dio~dv~t~g~ ia th~t when tho onc rotor h~
mor~ threads th~ 8m~1108t po~ible rotor pitch i~ alw~y~ gre~ter th~
wieh rotor pair~ ~ith the a~e nu~ber of thro~ds, a~ other~ise tho
~ooth thickne~ or thrcad thick~ess would ~ecom~ too small . Thi~ dic-
~dv~n~a~e ~l~o cauJ~ ~ li~it~tlon of tho ~uction hoad.
It i~ tho objoct of the i~vo~tion to de~olop ~ p~ir of convoyor ~crewc
of tho type d~cribad ~t the out~ot with a shor~ roter
lan~th nr~d ~ corroopondin~ly cm~ll di~t~nce batweon boarirlg oupports,
wi~h a low number of stag~s, a large tooth head width,
emull rotor pitch and a ~mH11 circumfersnti~1 ~ap leugth, to chus
cronto a ocr~ ~pin~La pump wit~ a rel~tivoly l~r~ co~v~ylng flow a~d
a high con~eying pre~ur~, uBing a limitod ~ount of ~teri~l. .
~cc~rding co tho invantion thi~ obj~ct io ~chio~od in ch~c thc prof ile~-
r~lat~d loc~ qQp h~ight in the axir ~ction o~ the ~itch clrcle 1~ kept
conot~nt for n ~pociflc ro~or ~l~ocor by ohifting th~ flank profile
revor~ing point ~ a functio~ of a tochnically cxocu~ble rotor pt~ch.
I~ this co~rl~ction it i~ exPcdio~t whc~ the fLank profil~ rc~Ar~ing
point climbs ir~ the raeio of rotor diameter to rotor pitch, ~n~ wt~en c~
fl~nk profile rever~ poi~t ~it~i~ the eeries, which i~ ch~ractoriz~d
by the rQtiO ba~e dia~ctcr : ho~d diametsr = N~ the rotor pitch
d~cres~s climb~ to ~bovn t~e pitch circle radiu~ up to a value of
m~xi~u~ r=l.
2141~55
.
....
It i~ fur~hcrmora ndva~tageou~ ~hen the clim~ o ~he fl~nk profile
r~vorHi~g poiut comm~c~ from ~ ~inimum value which iu gr~c~r th~n
tha pitch circle radiuJ, and ~h~n the profil~-relatod lo~ ~ap h~i~ht
in ~h~ ~xi~ ~ection on the pitch circle, which mu~t b~ kept con~t~nt,
lie~ i~ the ra~o 0,1% to 1,5~, pre~erAbly 0,1~ to 0,8% of tho rotor
diamot0r.
When co~voying liquid~ ~ith ~ high gac cont~t, aftor a ~hort oper~t-
ing poriod oft~ ~ hi~h loc~l co~pre~o~ he~t occur~, in p~rticular
ou the rotor cooth no~rest the pre~cure gid~. This may cau~o a local
circumforential g~p r-duction ~d fi~ally ~ ero~io~ by ~at~ri~l con-
t~ct (~rictional o~g~ nt). Accordinq to the invantion ~hi3 problem
1- to be oliminatod 1~ that with multi-otag~ rOtOrH o~ly th~ ~t8~e9
n~ront tho ~uction ~ide have ~ optimum loo~ ~p distrihutior, ~c-
cor~i~g to thc in~e~tion ~ ~xplain~d ln tho foregoing. A~ ~ reault
theroof, in thc ~xi~1 diraction of the rotor ~l~o g~s i8 compre~ffed
i~ido the enl~rgod 108~ g~p volums~; tho occurring co~pro~ion hsa~
i~ ~iatributod over 8 lar~r nurf~c~ of the rotor ~nd can be elimi-
~ted mor- favour~bly. Bec~o of ~ a loca~ ov~rh~ting of the
tooth ~cnd ia excluded. With theoo ~eaauroo tho pump for co~v~yi~ a
liquid ~i~h high q~e co~ten~s of more than 95% C8p for ~h~ ~irst time
bo dooigned rcli~bly ~it~ ~n optimum efficioncy. ~ccording to the in-
vontiou thie ie ~chiev~d in th~t with tho ~ul tl-~cage rotor ~he fla~k
p~ofilc reversing poi~t, up to the ~tage no~re~t the ~uctiou ~ide,
ch~n~a continuou~ly, step-by-~t~p or with multiple di~contlnu~i.on~
i~ ~he dircction o~ it~ opti~m po~itio~.
~ 5 5
-- 5
Thc minimum ~l~nk profil~ rovercinSI point i~ approximataly ~10 of
tho pitch circle pluff O, 2 . rhe ex~lct c~lculation takes plHc6 using the
formula q.. i n = 0, 6258 x O
According to the inv~r~tion tho di~advh~tago~ ~on~io~od /It thel oueffO~
~ith re~g~rd to the ~tato o~ the ar~ are, thor~fore, i~ pri~cipl~ ~ou~-
t~red by tho f ace that ~ h t~c dri~ring an~ drivon rotor, at th~ ~e
circ-J~f~re~ti~ p~d, ~he~ profilc~r~lated detrimental gap is split up,
~h~oir~ b~ ~suitablo mo~uro~ ~ho bat~c lc~s~ P, dep~rlding on ~ho pitch,
i~ mado up ~o 24 ti~ gr~atbr th~n tho ho~d lo~ g~p. A~ a ros-~lt
th~r~of a lo~er l~Q1cage flow flo~s e.locl~ tho tooth hoad, ~o t~at th~
tooth hoad i~ sl~o ~ub~octed to a leso woar. In ~dditior~, ar~ improved
volu~ctric efoce io obt~i~od, ~hich improvoJ ~he o~er~ll officie~cy
~nd onouroo 8 lo~qer lifo of tho ~cro~ ~pindle pump.
Wit~ the ~olutio~ ~ccordin~ to ~he i~Vontio~ deccribod abovo ~or
~ul~ a~o rotoro tho poJ~ibi1ity i0 cr~Htod to lot inco~pr~J~ible
modia flow b~ck th~ough ~ap~, b~t to compre~ compresnibl~ ~edi~ ovor e
lo~qer poch in th~ axi~l diroctlon. Irro~p~ctive of wheth~r ths profile
roVOrJing point cli~b~ to ~bovo th~ rotor lo~h, ~ho profilo rovcr~ing
point muot ~ y~ havo ite optimu~ at the rotor ~nd o~ tho ~ucti~ sidH
~nd ~u~t climb to~srdo tho rotor o~d on the preosuro ~ide i~ the direc-
tio~ of th~ ro~or rndiu~. An ~ ro~ult ther~of the loc~l h~at formatio~
o~ tho prQ~ur~ -oi~e will b~ eli~l~atod ~hrough t~e profilo-r~L~t~d gap
ovor the le~t~l of tho rotor. Tho profile-rol~ted gop will, ~hereforo,
beco~e am~llor to~rdH ths ouction ~id~. Thi~ m~a~ure, nlso ~ith high
~ 2141~5~
qa~ ratos reoultc in ~ ~hi~ting of the point of ~pplication of the
tran~vcru~ forco; it ic 8hif te~ from the preoauro oide middlo to tho
Hupporeing beoringo arra~god on tho ruction Pide, duo to which the
d~floction o~ tho ah~f~ io r~ducad. Such pu~p~ are suitabl~ ln p~r-
ticul~r for convoying crudo oil dir-ctly ~t the boreholo ~horo me~ia
l~tcrap~r~od with gn~ C8~ bo ~xpocted (~ulti-ph~se co~veying).
The inventio~ o sxpl~i~od in gr~tor detsil with r feronc~ ~o
~iagrams. With rog~rd to tho aymbols ~d terms which are uoed rof~-
r~nc~ do to the ~ovor~iew table".
Figuro 1~ - ~ho~o ~ pl~ne of ~ctio~ i~ face ooction for q_L~;
~iguro 1~ an illu~tr~tion ~ccordinq ~o Figure 1~ for q. . ~;
Figur~ 2 - ~ho~a ~n axial aoction profilo;
Flqur~ 3 - oho~a ~ axial oqction profilo gqp ~ith a compdrisoo for
q = 1, q ~ m, ~ = q~n ~t the ~e pitch ~d ~he ~amo
dia~ot~r;
Fig~rc 4 - oho~o An axl~ ccion profil~ g~p for q.~ n ~ud q~
F$~uro 5 - illuotra~e~ tho looo ~rea~ 1~ the meHhing zono in foce
section o~o~n dim~n~ionloo~ (R~/~K = 1 = r) at th~
tooth h~Qd and tooth b~e over tho profila r~verainq point
~ ith foot/h~ad ratio N~ = 0,4 a~d N~ = 0,65;
Figur~ 6 - io an 8xi81 ~o~tion profile ~ith continuouoly ch~nqin~
profllo production circle;
Figur~ 7 - Jho~ ~c st~to o~ th~ urt in lou~itudinal; soction ~ ffcr~
~pi~dl~ pUmp With ext~r~al bearing~ ~nd
,
~ ` 2111455
i~ure ~ - ~ho~ on ~ sm~llor ~c~lo tho Jcreu spindlo pump ~ccor-
ding to Figuro 7 in cro~s cactio~.
The ~crew ~piudle pump illu~t~atod in Figur~ 7 a~d 8 h~o ~o co~vey-
in~ ~lemonso two contactl~o m~hlng conv~yor screu poirc rot~ti~g
in oppo~ito dir~ctions, oach of uhlch compriaeo ~ ri~ht-hs~d thr~ad
convoyor ~cre~ ell ~ ft-ha~d thread conveyor ~cre~ 2 . Ac
ronule of thic t~o-flo~ arr~ngcment the axial thrust i8 co~peu~at~d.
The ~o~hin~ conveyor scrowc to~ther wlth the euclosi~ houoing 3
for~ i~dividual clo~ed-off convoying ch~mbers. Wh~n roc~ted by
drive ~haf~ 4 tho~o ch~m~er~ mov~ co~Si~uou~ly snd p~rall~l to th~
sh~ft~ from the ~uction to th~ prcs~ure side . The diroction of roto-
tion of th~ drive ~haft determi~cu the moveme~t arran~s~e~t of the
c~v~yi~g chs~berc. Thc pro~Jurc build-up take~ place practically
linoarly ovor the length of tho conveyi~g olo~ent~. Tho ~odium th~t
fl~a i~ or i8 su~kod up ~hrou~h chc ~uctlon connocclo~ 5 of ~ho pu~p
i~ fed i~ the pump houa~ng 6 i~ t~o partial f lows to the two ~uccio~
chamboro.
The torque trencmiooion from the drivin~ ~o thc drivon ~h~ft t~kc~
plac~ ~y ~ toothed-whHHl g~sring 7, the ~etting nf uhic~ e~ures rhe
co~t~ct-free runninq of tho conv-ying element~. The r~ference nu~er~l
~ indicatoo ~ otuffing box.
The ~irec~ion of rot~tion of the drive ~h~ft 4 i8 i~dicated ln Figure
7 by ~ha arrow 9. Figure 8 ahows disgr~m~tic~lly the preooure conn~c-
tion 10.
21414S~
Wlth ro~ard to the oth~r rQforo~o numerQl~, ploase ro~er to tha
~Overview t~ble~.
According to tho inva~tio~ the conveyor screw flankM ar~ made a~
~traight ~u pos~ibl~, ~volding co~v~x or co~c~vo sh~po~. The aim i~
an ~ ~mall ~ po~siblo proflle d-pe~de~t 10B~ ~ap. The optimum mu~t
bo fo~nd bet~eon the t~o extro~o ~aluea q=m ~nd q~l, wherein tho
eooth hod r~lated to tho tooth hei~ht muot b~ ~m~ll, tha toath head
~i~th gro~t and tho diot~nce bet~e~n tha me~hing too~h flanks small.
T~o~o requirement~ ~u~ bo mot unl~ormly ov~r a pitch range of the
rotor.
At q=l tha tooth hoad hoight ic zero; the tooth h~d ~idth i~ great-
e~t with H/2, but tho diAtanco bot~o~n fl~nk~ ell ~9 th~ tooth
b~oo lo~ are~ are groat~t~ Wlth a required mi~imal pitch at H
co~ant tooth ~hickneas thl~ is not practic~le. Alroady with ~ Rm~ll
cou~tor-preue~re, duo to tho large ba~o gap the roflux lo~e~ ~re
very qrest; the of~-ctivo co~veyln~ flow ~ reduced.
At the othor oxtre~e q=m tho tooth heQd iJ gro~te~t wlt~ half tho
tooth h~ight, tho tooth head ~idth s~allest; only ~ proflle depeudont
ho~d g~p i8 proeent. Up to tho middle of the ~aoth thc di~ance be-
t~een fl~nk~ i8 zoro and thon incro~se to ths m~ximum on th~ rotor
di~meter. Tho reaction forceu ~r~ greate~t, ~o ~hat o~ muut ~im ~t
Qrranglng q a~ ~ar away from this point a~ pos~lbls.
By th~ r.ing up accordinq ~o th~ invention of he~d ~hd hA~e ~ap3,
~141455
t~ g i~to ~ccount the surf~co ~riction ~gt~cn the conv0~0r ~cro~
flankc ~t tho ~e diff~ro~ti~l pro~uro, ospocially with low vi~-
co~ity convoying ~edi~ ~n~ tho~ ~ith ~ high ga~ conto~t, tha reflux
looa c~n bc ~iqnificarl~ly roduced. ThiJ re~ult~ in an improvomo~t in
th- afficioncy 88 ~11 ac ~ lffsser ~et ~e~r.
Iu tha cn~e of ~8 cont~i~ing ~odic, b~ tho moasura according to tha
inv~ntion tho occurring comprocsion ho~t i~ ~iotribut~d 1~ a ~peclfic
m~nner, thus count-r-acti~g a r~duction of tho circumforen~ial gap qt
the tooth h~d ~nd ru~nin~ noie~.
