Note: Descriptions are shown in the official language in which they were submitted.
C35~
1 Couplin~ ~rrangement and roller_mlll equipped there~lth
The invention relates to a coupllng arrangement (accordlng
to the preamble to claim 1), a device (according to the
generlc concept of clalm 9) for producing an ad~u~table
pressure between two component6 which ara movable relatlve
to one another, and a roller mill ~ccording to the ~eneric
concept of claim 10).
. 10 Hydraulic cyllnders of flat con6truction are known CDE-A-
38 20 373~ whi~h by mean~ of ~n internal spherical ~uide
permit a limited lnclined po6ition of the pi6ton rod
relative to the cyl-inder. Such-cyllnders can be u6ed when
two 6urface6 whlch do not lie parallel to one another ar0
to be 6upported without additlonal llnks or compensatln~
interpositlon6.
However, 6wivelllng movement6 of the two parts which are
6upported ~gainst one anothAr are only po6~ible lf the
polnt of rotation of the 6wivelllng movement i~ located in
the centre of the 6pherical gu-lde.
If ln addition to such a swivelling movement di6placements
also occur at right an~les to the cyllnder axl6 then addi-
tional elements (such as pl~in or antifriction bearings sr
ela6tomeric element6> are nece~sary to take up such tran~-
verse movements, or the end face of the piston rod mu6t be
of spherical con6tructlon ln order to be able to roll on
the counter-6urface, but this entail6 high surface press-
ures.
Depending upon the constructlon of these elements, durln~
the movement forces of reaction occur which ctrain both the
guidin~ of the piston and the participating component~. If
the ~ystem only permits }ow force~ of reactlon, thl~ ca~not
ba achieved with the arrangement descrlbed above or can
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1 only be achieved at very great expense ~for instance by
means of a hydro6tatlc slidlng bearlng~.
The ob~ect of the invention is to create a couplln~
arran~ement for connecting two componants which are movable
relative to one another which makes it po~6ible for both
component6 to be able to carry out, in addltlon to a longi
tudinal movement in the dlrection tow~rd6 one another, both
a swlvelling movement and a transver6e movement ln at lea6t
one direction at right angles to the lon~ltudlnal movement.
It ls a further ob~ect of the lnvention to build on ~uch a
coupling arran~ement and create a device for producing an
ad~u6table preeeure between two components whlch are
movable relative to one another, a de~ice which can be u6ed
in partlcular in a roller mlll of the type 6et out ln the
preamble to claim lO and which thus facilitates all move~
ment6 of the floatin~ roller occurrlng ln the operation of
6uch a roller mill as well ais lmproved ad~u6tment of the
zero gap in 6uch a roller mlll.
Thi6 ob~ect is achleved accordin~ to the lnventlon by the
characteri6in~ features of claims 1, 9 and lO. Advantage
ou6 embodiments of the lnvention are the ~ub~ect matter of
the subordinate clalm6.
Detail6 of the invention are 6et out in the followin~ de6-
cription of several embodlment~ which are lllustrated in
the drawings. In the drawing6:
F~ure 1 shows a horizontal sectlon throu~h a roller mill
equipped wlth the arrangement according to the ~nYentlon,
Figure 2 6how6 an enlar~ed repre6entation of on~ of the two
couplin~ arrangement6,
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- 3 - 2~
1 Figure~ 3 ~nd 4 show 6ections throu~h a further embodlment,
Figures 5 to 8 show 6ections through a ~urther embodiment.
The roller mill 6hown in Figure 1 contains two rollers 1
and 2 which are pressed a~ainst one another at hlgh pres6-
ure and of whlch the roller 1 i6 mounted as ~ fixed rollar
ln stationary bearin~s 3, 4 and the roller 2 ls mounted a~
Q floating roller in bearln~s 5, 6 which are movable at
right an~le~ to the roller axi6 (in the drawlng pl~ne of
Figure 1).
The movable beàrings 5, 6 o~ the floatlng roller 2 are
supported on a statlonary block 7 by means of cyllnder-
piston 6ystems 8 and 9 respectively. Thls cylinder-piston
systems ~, 9 are of the sama construction and constitute a
couplin~ arran~ement (wlthln the term6 of clalm~ 1 to 8~ or
a device <within the terms of claim 9> for producing an
adJu6table pres6ure between two components which are mov-
~0 able relatlve~to one another (namely the movable be~rin~s
5, 6 on the one hand the statlonary block 7 on the other
hand).
The construction of~such a cylinder-pl6ton ~y6tem 8 or 9 16
explained in ~reater detall below wlth the aid of Fi~ure 2.
The cylinder-piston ~ystem shown in Fi~ura ~ contalns ~
hollow piston 40 with two cylinder part~ 11, 12, of which
ln the case of the cylinder-pi6ton ~y~tem 8 the cyllnder
' 30 part 11 is connected to the movabla bearln~ ~ and the
cyllnder part 12 is connected to the ~tatlonary block 7.
The two cylinder parts 11 and 12 each have a central guide
lug lla, 12a.
A plston part 13, 14 engages in each of the two c,ylinder
parts 11, 12, and the cylindrical ~uter peripheral surface
'' : ~ . , ' , . - :
.' ~ . ',~ ' .
_ 4 ~ s~
13a, 14a of these piston parts i6 in fluid-tight contact by
means of seal6 15 ~nd 16 re6pectlvely with the cylindrlcal
inner peripheral surface 1lb, 12b of the cylincler parts 11,
12.
s
In the embodlment of the lnventlon illu~trated ln ~lgure 2,
the gulde lug6 lla, 12a havs a clrcular cro66-6ection in a
cross-6ectional plane runnin~ at right angles to the common
axis 17 of the guide lug~3 1la, 12a and the appertaining
cylinder parts 11, 12 (i. e. at rl~3ht an~le~i to the drawing
plane of Fi~ure 2~.
In the embodiment according to Figure 2 the pi~;ton part6
13, 14 have a cylindrical lnner peripheral 6urf~ce 13b, 14b
respertlvely. By contrast, the outer peripheral 6urfaces
11c, 12c respectlvely of the gulde lu~s 1la, 12a - vlewed
in a longltudinal sectional plane runnlng throuE~h the axl~
17 of the guide lug (approximately ln the drawing plane of
Figure 2~ - is curved ln a convex manner. 1herefore the
ao inner perlpAeral surfaces 13b, 14b of the pi6ton part~; 13,
14 co-operate with the outer peripheral 6urfaces 11c, 12c
of the guide luK6 1la, 12~ for guldinE~ purpose~;.
Thus the inner peripheral 6urfaces 13b, 14b of the pi~;ton
part~; 13, 1~ and the outer peripheral ~;urface6 11c, 12c of
the guide lugs 11a, 12a are con~3tructed in E;uch a way that
the two cylinder parts 11, 12 are able to carry out rela-
tive to one another not only a lon~itudlnal movement (in
ths direction of the axi~; 17) but al~;o a swivellinES move-
ment with any c:entre of ~;wivelling ~or in~;tance in the
centre Z of the floating roller 2 - cf. Figure 1), and
additionally ~ transver~ movement ln at least one dlrec-
tion at ri8ht angles to the cylinder axis 17. Thus the
cylinder-piston ~ ;tems 8, 9 permit all movement~3 of the
floating raller 2 which occur durln~ operation of th~
roller mill, and ln partic~llar al60 the incllnatlone o~ th~
:
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~ 5 - ~ ~5~
l floating roller 2 by an angle +J- ~ indicated in Figure 1.
The hollow spaces 18, 19, 20 between the cylinder partc 11
and 12 and the piston part6 13, 14 ara filled w.tth a fluld
and are connected to one another for example by connecting
channels 21, 22.
These hollow spaces 18, 19, 20 filled with a fluid are also
connected by a channel 23 provided in the cyllnder part and
a controllable valve 24 to an adJustable pressure mediu~
60urce which is not ~hown. Both cylinder-p~ston systems 8,
9 can advanta~eously be connected by separately adJu~table
valves to a common ad~ustable pressure medium source.
Furthermore, the spaces in the two cyllnder-piston systems
8, 9 which are filled with fluid are each connected to a
pre6sure medium store 25 constructed à6 a 6torage ba~ or
storage fla6k and to a pressure limitlng valve 26, Thu6 by
means of the cyllnder-piston sy6tems 8, 9 the two movable
bearlngs 5, 6 of the floatlng roller 2 can be ~ub~ected to
adJustable pressure6 or 6upportin~ forces.
A tran~verse displacement of the two cylinder part6 ll and
12 a~ain6t one another i5 taken up by an inclination of the
pi~ton part6 13, 1,4 which are connected to one another or
con~tructed inte~rally. The magnltude of the inclination
depend6 upon the ratio of the extent of the tran~verse dis~
placement and the length of the piston parts 13l 14. Small
lnclinatlon6 can be achieved by means of lon~ plston part6
13, 14.
The force of reactlon i6 produced from the friction force
between the inner peripheral surface~ 13b, 14b of the
piston parts 13, 14 and the ~onvex curved outer peripheral
surfaces 11c, 12c of the gulde lu~s 1la~ 12a.
The path of outward travel of the two cylinder-pi6ton
sy6tem6 8, 9 i6 advantageously limited by stop~ 27, 28
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l which co-operate wlth adJu6table ~top 6crews 29, 30.
In th~ embodiment illustrated in ~l~ures ~ and 4 the ~uide
lu~6 ~e.~. 11'~) of the cyllnder part6 (e.~. 1l') have a
rectangular, preferably ~quare cross-~ectlon in a ~ro6G~
6ectional plane running at right angles to the common axi6
of the ~uide lu~ and appertainin~ cyllndrical part <l.e.
in the drawlng plane of F~gure 4>. In a longltudinal
sectlonal plane runnin~ throu~h the axis of the ~uida lug
~drawing plane of Figure 3> the outer perlpheral 6urface
ll' of the ~ulde lug 1l'a co-operatin~ with the cylindric~l
inner peripheral ~urface 13b of the piston part 13' i~
curved in a convex manner, Thu6 a swivellln~ movement of
the pieton part 13' relative to the cylinder part 11' i~
pos61ble about an axl6 31 which constltutes the cylinder
axic of the cylinder part surface formed by the outer
peripheral curface6 11'c.
A further embodiment of the invention will be explained
2~ with the aid of Fi~ures 5 to 8, an~ in this case the 6ame
reference numerals will be u~ed for the same component~ a~
ln Figure6 1 to 4. This embodiment of the coupling arran~e-
ment facilitates in particular an advantageous adJu6tment
of the 60-called zero ~ap of a roller mill.
Before the material for ~rindln~ is dellver~d to the two
grinding roller6 of a roller mill, it mu6t be ensured that
tha floating roller i6 clamped hydraulically or mechanic-
ally with a certain initial tenslonal force in a fixed
position ~the ~o-called zero ~ap po61tion> relative to the
fixed roller. In thic zero ~ap position the two ~rindin~
rollers do not touch each other ~t the narrowqst polnt of
the ~rindin~ ~p. The air ~pace at thl~ narrowest point i~
known ac the l'zero ~ap".
Until now the floatin~ roller ha~ been flxed ln th~ zero
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1 ~ap position by pressing the floatin~ roller unit hydraul-
lcally with gre&t force by means of the workin~ cylinder~
a~alnst stop blocks whlch in turn are Qupported on the
fixed roller unit. However, thi~ method of adJu6tlng the
zero gap has two sub6tantial diQadvantages.
In view of the high stresses due to the great initial
ten6ional f~rce, all bearing ~ewel~ must be of very stable
construction, and above all the deformatlon of the bearing
10 Jewel~ of the floatin~ roller must not exceedrelativ91y
low limitlng values.
In view of the a~dltion of~:unavoidable tolerance~, the
position of the central axi~ of the floatin~ roller deter-
mined by the initlal tenslonal force ls not exactly at
right angles wlth reference to the machine frame, and ln
the case of mountln~ wlth cylindrical bearin~s (these are
plaln bearln~s and cyllndrlcal roller bearing~-) thi~ can
lead to forcln~ of the floatln~ roller ehaft at the two
bearing point~ and to re6ultlng breakdown~. -
The disadvanta~es of the zero gap ad~u~tment indicated
above can be avoided by the further embodlment of the
couplin~ arrangement accordin~ to the lnvention which i6
shown in Flgures 5 to 8.
In thi6 embodiment a stop head 32, 33 respectively i~
connected to each of the guide lu~s lla, 12a of the two
cyllnder part6 111 12 and deflne6 the maxlmum di6tance
` 30 between the two cyl~nder part~ 11, 12 by stop engagament
with the appertaining plston part 13, 14 of the hollow
pl~ton 40.
In this ca~e a free intermedlate member 34, 35 i~ provided
ln each cese between a level ctop surface 32a, 33a of the
stop head 32, 33 and the ~soc1ated pl~ton part 13, 14 of
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1 the hollow plston 40 and is constructed on its ~urface
facing tha pi6ton part 13, 14 as a ball cup 34a, 35a which
i8 in contact with a complementary ~pherlcal surface 13c,
14c of the piston part 13, 1~.
The stop heads 32, 33 are connected by a ~crew thread 36,
37 to the ~uide 1ug5 lla, 12a, 50 that the axlal distance
between the stop fiurface 32a, 33a of the 6top head 32, 33
and the base 6urface lle, 12e of the cyllnder part6 ll, lZ
l~ i6 adJustable. Instead of thls lt is ~lso po6slble within
the ~cope of the lnvention to provide a fixed connectlon
between the 6top heads 32, 33 and the ~ylinder part6 ll,
12.
The outer peripheral 6urface llc, l2c re~pectlvely of the
cylinder part~ 1l, 12 which i5 in contact with the cylln-
drical inner peripheral 6urface 13b, 14b of the pi~ton
parts 13, l4 i8 ~160 curved in a convex manner ln this
embodiment.
~0
In thls embodiment the 6wivel artlculation of the cylinder
part~ 11 and 12 relative to the hollow pi6ton 40 and tne
6wlvei articulation of the hollow piston 40 relative to
each of the two cylinder part6 11l 12 18 al~a maintained
~5 when the lndividual parts are located ln the po~ition ~hown
in Fi~ure 5, which corre6ponds to the zero ~ap posltion of
the floating roller. Thus when hydraulic oll i8 delivered
under pres6ure the two cyllnder part6 ll, 12 csn only
travel outwards as far as the stop head6 32, 33 allow,
Thu6 the entire cyllnder 6y6tem ls under an lnternal pre-
stre6sin~, whilst the cylinder which is prestressed intern-
ally i6 free of force toward6 the exterior. Thus tho bear-
in~ Jewels of the floatin~ roller (bearings 5, 6 according
to Flgure 1) al60 remain load-free in the zero gap posi
tion; in contrast to the zero gap adJu6tment whlch wa6
u6ual in the pa6t no external force6 act on them.
:
2 ~ 5 ~ ?~ ~
l Since in thi6 2ero ~ap posltion of the coupling arrangement
the articulation of the double ~oint cylinder formed by the
two cylinder part6 ll and 12 and the hollow plston 40 i8
fully maintained, the bearin~ Jewel6 of the floatin~ rollar
S ~bearing6 5, 6 with cylinder parts 11 connected thereto~
can swivel by a ~ertain amount relatlve to the machine
frame. Thus the bearln~ Jewel of the relevant bearin~ i8
no lon~er pres6ed into any forced positlon, but can adapt
to the partLcular po6ition of the 6haft, ~o -that in the
CA6e of cylindrical bearings unde6irable end pres6ure6 are
avoided. For the adapting movement of the bearing ~ewels
it is merely neceseary to overcome the friction torque of
the spherical support ~ball CUp6 34~, 35a> lyin3 under oil.
However, this friction torque i~ not very great becau~e of
its relatively short lever arms.
If durin~ the ~rindin~ operatlon the floatin~ roller l~
pushed back by the matarial drawn into the ~rindin~ gap
then the parts of the coupling arrangement take up a
relative po6ition as 6hown 6chematically in Fl~ure 6. In
this case the stop head6 32, 33 lift off from the level
counter-6urfaces of the int3rmediate member~ 34, 35. Thu6
a dynamic ~Rp 38, 39 is produced in each ca~e between the
top head6 32, 33 and the intermediate members 34, 35.
If the quantity of material for grlnding delivered to the
roller mill is reduced and the delivery i& stopped, then
the grindin~ operatlon chan~es a~ain to zero ~ap operation.
The ~top heads 32, 33 ara applled to the intarmediata
` ~0 member6 34, 35 ~o that the flux of force i~ again closed
within the cylinder system formed by the cylinder part6 11,
12 and the hollow pi6ton 40,
However, it i~ al60 po66ible that thls renewed contact
between the stop head6 32, 33 and the intermedlate members
34, 35 re6ults ~rom a pravious incllnatlon of the ~loatlng
.
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1 roller, The situation occurrln~ in this ca~e ls shown in
Figures 7 and 8, In this case the contact is not 6imul-
taneou6 and uniform on the two circular 6urfaces (l,e, the
6urfaces 32a, 34b or 33a, 35b> which face one another), but
be~ins at one peripheral point which i6 initlally ~till
free of force (cf. Fi~ure 7),
With lncreasin~ contact the force on the contact point
lncrease6 until with the flnal stoppa~e of the dellvery of
material for grinding to the roller gap it has reached it6
predetermined ma~nitude for the zero ~ap operation ~cf.
Figure 8),
In kinematic terms the following occurs between the stop
head 32, 33 and the appertainln~ intermediate member 34,
35:
The central axis 40a of the hollow pi~ton 40 is inclined by
a small angla (maximum of approximatel-y 3-) with respect to
the axls 17 ~cylinder part with 6top head in horizontal
plane), If the free intermediate member 34, 35 contact~
the appertainin~ stop head 32, 3~ at a point then a torque
occurs on the intermediate member which rotate6 by mean6 of
lts ball cup 34a, 35a into a force-absorbing position.
This force-~b60rblng po~itlon is raached when no unilater-
ally actln~ force, i,e, no torque, scts any more on the
lnter~ediate member 34, 35. Thus the two cylindrical sur-
face6 32a, 34b or 33a, 35b have reached a posltlon parallel
to one another which ls necessary for the transfer of
pre~sure forces, After thi~ parallel position has been
taken up the lnitlal tensional force belon~ln~ to the zero
gap position can then be transferred,
The point of rotation M1 formed by the ball cup 34a or 3~a
re6pectlvely and the point of rotation M2 of the hollow
piston ~0 do not need to be ident1cal. In~arly case durln~
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26~
l adJu6tin~ movement~ of the stop heads 32, 33 they change
thelr relative po6itlon. The point of rotation M2 of the
hollow piston 40 lie6 fixed in 6pace or ln the horizontal
? plane1 whilst the point of rotation Ml of the ball cups
3~a, 35a change~ in ~pace or in the horlzontal plane. The
point of rotation of the ball cups 34a, 35a alw~ys lies on
the central axis of the hollow pi~ton ~0. If the hollow
piston 40 change6 its angular posit~on, then the point of
rotation M1 of the ball CUp6 34a1 35a move6 on an arc of a
circle with the point of rotation M2 of the hollow pl~ton
~ the central point.
The so-called 6iope of the spherical ~upport formed by the
ball cups 34a1 35a i8 of course chosen 60 that the 6upport
lS i6 not 6elf-locking but the intermediate member 341 35 can
also rotate into its force-absorbing position with a rela-
tively small rot~ry moment,
The zero gap can be adJusted by chan~in~ the over~ll len~th
of the double ~oint cylinder for~ed by the cyllnder parts
11, 12 and the hollow piston 40 to the de6ired value.
Shortenin~ the overall length of the cylinder sy6tem m~kes
the zero gap greater1 whilst lengthenln6 lt makes the zero
~p smaller. The~changes in the overall len6th of the
cylinder 6ystem are achieved by ad~ustin~ the 6top he~d 33
f~cing the bloclt 7 by means of a spindle which ls pa~sed
throu~h the block 7 and en~a~es ln a rece6s 33c in the 6top
head 33.
`30 The limits for the an~ular movabllity of the two cylinder
part6 11, 12 relative to the hollow pi~ton 40 re~ult from
the clearances between the cylinder part6 and hollow
pi6ton.
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