Note: Descriptions are shown in the official language in which they were submitted.
07-RPR-1995 07:49 RIr_HTER & PRRTNER +49 40 352415 S.02
21~3~~.~
._ . - ~ _
Vane Cell Machine
SCOPE OF APPLICATION
the present invention relates to a vane cell machine for
liquids, comprising a rotor having radially proceeding guide
slots mounted in a stator, in which slots radially displa-
ceable Vanes are slidingly disposed which, while acted upon
by centrifugal forces, can be pressed against an inside wall
of the stator, wherein, in the course of a rotor rotation,
delivery cells are formed which expand or narroN in a cres-
cent-shaped fashion and the entry of the liquid takes place
through a tubular internal stator and the filling of the vane
cells is effected from the inside to the outside.
STATE OF THE ART
Vane cell machines are constructed in the form of fixed dis--
placement pumps nr fixed displacement motors or in the form
of variable displacement pump or variable displacement motor.
Howevarr v2ne cell machines are likewise employed in the form
of volumetric meters. The advantages of the vane cell machines
reside in their uniform delivery flow and in their quiet run
ping. Problems do arise though due to the respective hydrau-
lic radial and axial bearing loads.
The hydraulic radial bearing loads in vane cell machines pos-
sessing rotor lengths equal to the operating area of the va-
nes result from the product of the projection surface, for-
med of rotor and projecting vane and the hydraulic pressure,
i.e. the pressure differential acting upon the rotor. Smaller
radial loads result from the friction of the vanes on the sta-
tor and in the rotor slots as well as from the dead weight of
the rotor. In order to intercept the altogether resulting
radial forces and the powerful forces occurring already at
RPR 7 '95 02:46 +49 40 352415 PRGE.0~2
07-faPR-1995 07:49 RICHTER & PRRTNER +49 40 352415 S.03
21~~71~
- 2 -
minor pressure differentials, the rotor shafts and supports
are either dimensioned so as to be sturdy or it is atempted
to provide an equalization bymeans of costly and - from a
point of view of ftuidics - disadvantageous mufti-stroke
pump or motor constructions.
The hydr-auL~c axial bearing toads Can be avoided by the sym-
metric design of the axial hydraulically effective areas of
the rotor, in which case the hydraulic pressures exerted on
the effectice areas have to be uniform. In the embodiment
preferred for reasons related to production engineering and
costs and possessing an axially displaceable rotor, the
same bears against the stator within the area on one side,
while the hydraulic pressure becomes more effective on the
opposite side so that no axial power balance exists. It
would be possible to provide a remedy with the aid of any
axially immovable construction of the rotor support with a
precise, uniform adjustment of the front end rotor gap,
which, however, is expensive. Thus, by way of example, for a
pneumatic compressor or motor related to the subject matter
of the apptication, pneumatic pads in some of the recesses
machined into the front ends of the rotor are provided accor-
ding to the DE-A-21 33 455 and which are located between the
guide vanes and are supplied with compressed air through
ducts machined in a crescent-configured manner into the late-
ral covers of the housing so that, when the rotor is axially
displaced, pressure differentials occur between the pneumatic
pads located on both sides of the rotor, which exert repel-
lent farces in the direction of a central position.
A comparatively costly solution i~ likcwisc propo~cd in the
DE-A-31 2Q 350 for a vane veil machine, in which the shaft
rotor is designed ~o ac to pQa~c:,:, tKV lc7rgc axially dig
pLaceabte bushings which are acted upon by the teed pressure
in prossurixed gaps in axially di~pLaCcablc bearing bu~hingc
on the rear sides and front ends in order to bring about a
RPR 7 '95 02:46 +49 40 352415 PAGE.003
07-APR-1995 07:50 RICHTER & PARTNER +49 40 352415 5.04
21~3'~~~
3 -
a pressure equalization on the shaft rotor so as to minimize
the bearing loads and trictional tosses. Disadvantageous is
the large and expensive number of precision components in
the hydraulic operating sphere, relatively large requisite
gap lengths between the high-pressure and low-pressure area
and the poor efficiency of the vane cell machine resulting
from this. Furthermore, the shaft for the motive power and
the power take-off projecting from as rotary piston pump,
due to the pressure differential on the shaft seal and with
slip ring seals gives additional rise to axial bearing Loads
by means of the spring tension of the same, unless a compen-
sation is effected on the opposite side by means of a sym-.
metric ConStruCtiOn.
Moreover, rotary piston pumps are known e.g. from the D~-AS
12 36 64'!. TharP, in a ~tatnr hof(.~~r sp2ca of rnnstant dia-~
meter, a cylindrical revolving rotor with a plurality of
substantialCy radiaC sCots, in which vanes are sliding, is
supported, in which case, by means of a pertinently wavy
configuration of the cross-sectional contour of tho stator
cavity, several delivery cells are formed between the stator
and the rotor to and from which the pumped or operating me-
dium is suppCied and removed via tangentially terminating
ducts, of which intake or Low-pressure side ducts are in
each case bores located on one side of the vane that lead
to a concentric, hollow rotor space, while the ducts on the
high-pressure side located in each case on the other side
of each vane, coromurri~atr irr each case in d corrrirwous lon-
gitudinal duct of the rotor allocated to each vane. The lon-
gitudinal ducts communicate in turn with an annular groove
which communicates with the high~pressure side of the pump
or the motor.
pPR 7 '95 02:47 +49 40 352415 PAGE.004
07-RPR-1995 07:50 RICHTER & PRRTNER +49 40 352415 5.05
_ 2143~1~
For the direct feeding and removal of the pumped medium it
is also known to provide duw leading into or vut from
the delivery cells, which will then have tv communicate in
turn with ducts in a sLaLionary housing portion. The use
of such rotor ducts is regarded as advantageous in as far
as e.g. one orwrvr~e operating spacefs) exist bezween the
rotor circumferential area and the circumferential wall of
Lhe stator hollow space since, when correspondingly many
intake and discharge apertures are disposed in the stator
walls, Large parts of the operating spaces are unable to
act as areas within which the displacement cells are sealed
oft from the inlet side and the pressure side, unless a
great many pumping operations are planned which once again
diminish the utilizable operating space and give rise to
substantial friction losses.
In order to be able to construct the feeding and the dis-
charging ducts in the rotor so as to possess an adeauate
Width but, on the other hand, to avoid too great a weake-
ning of the rotor owing to the ducts and, finally. to pre-
vent an axial thrust from pressure ducts having an adverse
effect on the pressure, it is further proposed in the DE-AS
1~ 3b 941 that, in the form of delivery~side ducts on the
respective side of each vane, sQVaral grnnvec he machined ,
into the relevant wall of the associated rotor slot, in
which r..ase, furthermore, on both sides of the rotor, one
annular groove each be disposed in the side walls of the
stator which face the rotor front walls, into which thr
delivery-side longitudinal ducts of the rotor terminate,
while the annular graove~ arc in communication with pres-
sure connections of the pump or of the motar_ The rotor
hollow space into which the towwpressure-side bores lead,
is a part of a concentric longitudinal bore of a shaft con-
nected to the rotor. However, thisrotGry piston pump i5
RPR 7 '95 02:47 +49 40 352415 PRGE.005
07-RPR-1995 07:50 RICHTER & PRRTNER +49 40 352415 S.06
~143'~~.~
- 5 -
expensive to construct on account of the numerous radial
bvr-es - also outside the vane slots - as well as owing to
the great number of outlets.
The U5-A-3,361,076 describes a vane cell motor with a ro-
tor supported in a stator, said rotor being slatted within
its operating area which, screwed together with each other
is comprised of a accommodation space for the vanes, a
terminal piece and a flow sleeve. The accommodation for
the vanes comprises a terminal flange which, lust like the
terminal piece, projects radially over the external dia-
meter of the stator element and thereby laterally limits
the hydraulic operating area. The accommodation for the
vanes is, in the axial direction, outwardly construcrpd
in the form of a shaft, supported on ball and roller bea-~
rind elements and sealed in the stator and caused to pass
out from the vane cell motor for receiving a driving ele-
ment. In thlS l'.r7SP the terminal piece possesses only a
short shaft shoulder for accommodating the rolling bearing.
The filling of the vane cells is effected in this case
from the inside to the outside while a rotor is provided
shove the slotted area uF,ich is extended to both sides
having a greater external diameter for the positively lo-
cking axial centering of a displaceable lifting ring. Both
extensions are mounted by means of tapered roller bearings,
3Lao for the absorption of radial anil axiel for-crs, in the
housing while the one extension is passed out of the machi-
ne in the form of a rotationally Sealed shaft for the drive
connection. Pressure-adjustable overflow valves limit the
gap pressure witlnin the gap areas arising due to leakage
caused by the operating pressure which, at the same pres-
sure via l,Irese gap areas up to the seal diameter, brings
about a pressure equalization. The axial hydraulic forces
across the rron-pressure-equatized Surface area below the
sealing diameter are absorbed by the bearings. In this vane
yell molar the vanes are spring~-loaded, whereby a high
RPR 7 '95 02:47 +49 40 352415 PRGE.006
07-RPR-1995 07:51 RICHTER & PARTNER +49 48 352415 5.07
- ~I~3'~~~
- 6 -
degree of proneness exists in so far as, when the spring
pressure falls off, it is no Lnnrder Assured that, in the
operative state, it wilt be possible for the vanes to be
brought to the inner wall of the stator, in addition, a
rotation of the rotor to the stator has to be ensured in
Sur:h a way that a retracting of the vanes into their re-
ceiving slots in the rotor against a spring pressure is
possible_ To this is added the circumstance that the
three-part rotor is constructed neither to be shiftless
nor in a tubular manner, which does not pusse55 a vane
slot which is continuous from the internaE to the ex-
ternal diamettr since the internal diameter is formed by
the ftow sleeve. The pressurized space of the stator does
not contritrute within the area of the rotor extensions to
the compensation of radial forces which, from the opera-
ting Nressure, can only become effective onto the rotor
portion. The same pressure present in the gaps, adjustably
limited by means of valves, avoids for the effective areas
going beyond the seating diameter axial forces by means
of thisd pressure, it does, however, leave the effective
surfaces below the sealing diameter axially uncompensated
pressure-wise.
In the US-A-3,153,384, a vane cell pump is described, in
which, on a common shaft and axially rigidly tightened,
two rotors separated by a spacer, two supporting rotors.
two spacing sleeves and two equalizing disks are disposed.
The Supporting rotors are Supported in a friction bearing
in bushings in a housing, in which, for the compensation
of radial hydraulic forces, pprtinpnt recesses acted upon
by operating pressure are disposed. The operating pressure
is conducted through external pipelines from the pressure
side to the recesses in the bearing bushes. In this vane
Gall pump, effective Surface areas acted upon by operating
pressure and directed against the rotor are provided in
RPR 7 '95 02:48 +49 40 352415 PAGE.007
07-RPR-1995 07:51 RICHTER & PRRTNER +49 40 352415 5.08
21~37~9
- 7 -
the stator. For the compensation of radial hydraulic for-
ces in vane cell machines or vane pumps possessing a
rotor supported in friction bearings it is accordingly
known to provide, in the loaded friction bearing area,
effective surface areas acted upon by operating pressure.
It is disadvantageous ir, this vane purrn that adJitional
gap entry edges acted upon by operating pressure and pos-
sessing relatively short gap lengths and that thereby
the efficiency is impaired by increased volumetric losses.
Moreover, the formation of hydrodynamic pressure suppor-
ting surfaces is prevents to a very large extent since the
narrow gaps necessary for this within the supporting bea-
ring area are eliminated by the effective areas acted upon
by operating pressure which are planned at this point.
According to the FR-A-73 95 435, a vane cell machine is
known, in which, in a stator, a shaft-journalled rotor ro-
tates, wherein the inner shell surface of the stator pos-
sesses three pitch-cirular recesses, whose wall areas are
run in such a way that the combination area of two wall
areas each comes to be located in the external rotational
area of the rotor. The rotor is provided with radially pro-
ceeding guide slots for four vanes, in Which case the dis-
position of the guide sln*s is such that two oppositely
Located guide slots each are, relative to a theoretical
radius line, ars raciprocaCly staggered with the result
that only one vane each comes to be lie in each indivi-
dual pitch-circular reec~~. A slide or journal bearing
lubricated by delivery liquid of the rotor shaft is not
provided in this case.
The DE-A~2 022 $49 describes a valueless rotary piston
pump with circularly rotating vanes assuming the delivery,
which is comprised of a stationary sectional axis which
determines the position of the vanes in the individual
operating phases, wherein the hollow drive shaft is
RPR 7 '95 02:48 +49 40 352415 PRGE.008
07-RPR-1995 07:52 RICHTER & PRRTNER +49 40 352415 5.09
- 2i~37I~
eccentrically supported in the pump casing in such a way
that, within the operatirry area, an adequate delivery
cross-sectionremains between the hollow shaft and the ca-
sing and, within the separating area, the hollow shaft
rests sealingly against the casing and thus takes charge
of the separation between pressure and intake side. The
vanes, which bring about the drawing in by suction and the
delivery of the medium, project in the operating area so
far from the hollow shaft that they reach the casing wall.
The drive shaft is in this case constructed in the form
of a hollow shaft, in which the vanes are supported so as
to be radially displaceable and are supported on a rigidly
dislocated sectional axis, xhile the hollow shaft is supw
ported in the pump casing. A shaftless support is thus not
provided.
In the rotary piston pumps known according to the state of
the art which are provided with vane cells for liauids,
which are employed in the form of delivery pumps, an opera-
tion far liauids with elevated vapor pressure and without
a positive supply feed owing to the net positive suction
head rapidly ring with thp rotational seed, an operation
with economic drive speeds of e.g. 1450 min-~ and higher
is no Lnngpr ~nRRihlp.
The volumetric degree of effectiveness and the dry intake
Capacity (with an empty pump) of vane pumps is determined
by the gap losses, whose magnitude - with the presupposi-
tion of the same delivery product, the same manufacturing
precision and pressure differential - depends on the lengths
of the gaps. That is why, with a comparable pump flow,
sLowiy rotating pumps with a correspondingly great cyclic
pump volume and pump Lengths possess poorer volumetric
degrees of effectiveness and a lower dry intake capacity
RPR 7 '95 02:49 +49 40 352415 PRGE.009
07-APR-1995 07:52 RICHTER & PARTNER +49 40 352415 5.10
- _ 9 _ 21~3~1~
than rapidly rotating pumps with a correspondingly smaller
CyCllc pump volume and gap lengths. These technical con
nections mentioned, on account of the necessary reduction
of the rotary speed by the net positive suction head limit
also the possibilities for the constructional improvement
of the volumetric effectiveness and of the dry intake ca-
pacity.
Furthermore, rotary piston pumps for liquids, as a result
of the Large projection area formed by rotor and projecting
vanes and acted upon by the pressure differential, call for
sturdily dimensioned shafts and bearings, unless the rotary
piston pumps are constructed in the form of double~stroke
vane pumps or motors which each possess two intake and disw
charge apertures for the liquids, a step which is costly
from a product engineering aspect and which, in the case
of pumps, leads to an increase, and with this, to a dete~
rioration of the net positive suction head.
TECHNICAL PROBLEM~~ TECHNICAL SOLUTION, AbVANTAGES
That is why it is the technical problem of the present in-
vention to further develop the known vane pump in such a
way that a complete or at least extensive balance of the
radial and axial fort a is provided, in which, with a view
to a longer useful service fife, the wear should be miniw
mined and a greater degree of effectiveness ectnieved. So
far as vane cell machines are considered as volumetric
meters, the measuring accuracy is intended to be improved
in a like manner. It is further the object of the present
invention Lo ~xparTd the possibilities of operational appl y
cation in the form of a pump by means of a reduction of
the net Nvsitive suction head and to improve the degree
of effectiveness in the machine employed in the form of
a Nump. In addition, it is Lhe Object of the present in-
vention to also improve the hydraulic axial and radial
APR 7 '95 02:49 +49 40 352415 PAGE.010
CA 02143719 2000-12-07
- 10 -
stresses at least in part or altogether by means of con-
structional steps which do not involve any great construc-
tional effort or costs.
Thus this invention seeks to provide a vane pump for liquids comprising a
stator having an inner wall surface and a hollow center, a shaftless and
tubular rotor
mounted on the hollow center of the stator, the rotor having in a vane area
thereof
radially extending vane slots, the vane slots extending from an inner diameter
to an
outer diameter of the rotor, a vane being slidably mounted in each vane slot,
the
vanes being configured to bE: pressable against the inner wall surface of the
stator
when a compressive force is applied to the vanes, radial recesses being
defined in at
least one of the vane slots and the vanes, crescent-shaped delivery cells with
an
increasing or decreasing width being formed between the outer diameter of the
rotor,
the inner wall surface of the stator and the adjacent vanes, the rotor having
at both
ends thereof extensions protruding beyond the vane area, the extensions having
a
diameter equal to or smaller than the outer diameter of the rotor in the vane
area, the
extensions being received in the stator so as to form a gap seal, wherein the
liquids
enter axially through the hollow center of the stator and radially through a
window
defined in the hollow center of the stator in an area of a delivery cell with
an
increasing width and through the radial recesses into the delivery cell with
the
increasing width, the hollow center of the stator having recesses adjacent the
extension of the rotor, wherein the stator recesses are configured to receive
an
operating pressure and the recesses having a location and size configured to
partially
or completely compensate radially directed hydraulic and weight-related
forces.
CA 02143719 2000-12-07
- l0A -
According to this the invention consists in that the rotor
of the vane cell macshine is constructed so as to be devoid
of a shaft and of tubular configuration and in that both
sides are extended beyond the operating area determined by
the vanes and supported with the extensions in the exter-
nal stator and in that it possesses continuous vane slots
from the internal to the external diameter and in that the
stator frame, within the area of the rotor extensions,
possesses on the surface hydraulically effective areas;ac-
ted upon and/or relieved by the operating pressure directed
against the rotor for the at least partial compensation or
avoidance of radially occurring forces. However, in a shaft-
less rotor extendingi beyond the operating area toeards both
sides, the operating pressure becomes effective in the
bearing gaps rotor/external stator located there, which
results in further bearing loads. In comparison with it,
by means of recesses (effective areas) in the stator frame
relieved of the operating pressure, this radial load por-
tion is significantly reduced. The tubular extensions on
both sides are lubricated with delivery liquid due to the
pressure-dependent gap leaks and slidingly supported in
the stator.
The vane cell machine is, according to a further embodi-
ment, provided with an inlet for the liquid through a hol-
low central stator, in which case the ducts for filling
the expanding vane cells are formed by radial recesses in
the vanes and/or in the vane slots and the concentric sta-
tor possesses on its surface effective areas acted upon
07-RPR-1995 07:53 RICHTER & PRRTNER +49 40 352415 5.12
- 2143 rllg
- 11 -
by operating pressure and directed against the rotor for
the at Least partial compensation of radial. farces, it
being possible to sub~itute the recesses with small bores
acted upon by operating pressure Which produce, in the
bearing or supporting gaps, rotor/external stator, large
effective araas directed against tha rotor_ This step is
simpler in the fabrication, results in comparatively
Lower gap losses and thereby improves the volumetric de-
gree of effectiveness. Advantageously, this vane call ma-
chine i~ of ~implc construction, a comparatively expansive
additional mounting of the shaft and the frictional forces
arising t,erefrom are avoided trom the outset, just as
axial and radial hydraulic forces are minimized.
In this case the radial ducts for filling the delivery
cells are formed by radial recesses in the vanes andlor in
the vane slots which proceed continuously from the exter-
nal diameter to the longitudinal bore in the form of a
shaftCess rotor projecting on both sides beyond the opera-
ting area determined by the vanes, while the liquid enters
axially through the hoCCou rotor axis and the fiEling of
the of the expanding delivery cells takes place in the the
radial direction through a window in the rotor axis and,
in the further course, through recesses in the rotor slots
andlor in the vanes.
The rotor portion which projects beyond the c~peratiry erea
or the rotor portions on both sides are rotatable against
the rvtor~, bul ar-a fitted in sealingly_ In pumps, in res-
pect to the net positive suction head, a significant advan-
laye results since solely zhe introduction lasses of the
liquid into the rotor slots are to be associated with the
rrrl positive suction head and the further pressure lasses
up to the filling of the vane ceCls and the speed increase
of the liquids connected with this in conjunction with the
RPR 7 '95 02:50 +49 40 352415 PRGE.012
07-RPR-1995 07:54 RICHTER & PRRTNER +49 40 352415 5.13
- ~~4~71~
- 12 -
centrifugal -force have to be produced energyNise by the
drive. The radial filling of the vane cells from in~idc
via the rotor slots, over and above that, has the advan-
tage that the inr.lusion of the stroke volume of the vanes
in the rotor slots takes place in the cyclic operating
volume of the pump or of the motor without a special fil-
ling operation for this stroke volume against the centri-
fugal force, as i~ necessary Hhen the vane cells erw fil-
led tangentially or axially from the outside according to
the state of the art. The rotor axis serving at the same
time as liquid intake and as a mounting means for the ro-
tor does advantayeuu5ly make possible in pumps and motors
a cost-saving realization of the hydraulic, in particular
radial, Nressure balance by means of a hydrauW c support
against the rotor axis.
Further developments of the invention are described in
the subclaims.
The recesses are thus preferably acted upon by the opera-
ting pressure given by the liquid ~o that no further pres-
sure sources or control means are necessary.
According to a first embodiment, the recesses in the sta-
tor shell are located opposite the external rotor casing
outside the vane operating area, thus, Nith regard to a
vertical area passing through the vane operating area,
symmetricalyl disposed. According to an alternative embo-
diment, the recesses are located in the shell of a stator
pivot Hhich reaches through the concentric opening of a
rotor tube and bears against the same in a sealing fa-
shion. The last-mentioned embodiment possesses the advan-
tage that the recesses may also Lie at the same level as
the vane operating area, Nhereby a reduction in the over-
all height may possibly result. Combinations of said em-
bodiment are likewise possible.
RPR 7 '95 02:51 +49 40 352415 PRGE.013
07-RPR-1995 07:54 RICHTER & PRRTNER +49 40 352415 5.14
'.
- 13
According to a further construction of the invention, the
rvtar portion Which projects beyond the vane operating
area possesses an identical or reduced externs! diameter
in comparison with a diameter in the vane operating area.
A reduced diameter outside the vane operating area pos-
sesses the advantage that, in the course of the vane cell
machine operation, the rotor receives an axial centering.
Nhen the vane cell machine is inoperative, the vanes imy
merse into the rotor slots whereby, in a rotor poSSeSsing
a continuous constant diameter, axial displacements may
be possible. In the rotor extended with reduced diameters
which otherwise is axially freely movable, the diameter
increases serve to center the motor in relation tn thp
operating area, in which case it is possible to put up.
with the afaredescribed disadvantage of thp un;lateral~ly
greater effectiveness of the hydraulic pressure by bearing
against the oppositely Iw ated side since the effective
area is kept smalE by a minor difference in diameter. By
means of this rotor Centering in relation to the operating
space, between the front end areas of the rotor and the
stators on both sides, the gap for a hydrostatic force
balance at the same pressure is ensured.
In the rotor extended with the same diameter towards both
sides, the requisite centering of the rotor relative to
the operating area is effected by the vanes. The space in
the guide slots underneath the vanes communicates with the
vane cell located before the same in the direction of ro-
tation, e.g. by means of radial recesses in the vane and!
or in the rotor. Since, in the inoperative state of the
vane cell machine, the vanes moved outwardly by centrifu-
gal force when operative, can be immersed into the rotor
and the freely movable rotor may be axially and unilate-
rally displaced against the front-end stator and because
RPR 7 '95 02:51 +49 40 352415 PAGE.014
07-RPR-1995 07:54 RICHTER & PARTNER +49 40 352415 5.15
214~7~.~
- 14 -
this may, uhen the pump is started up, hinder the vanes
from emerging or may even lead too tilting or wedging
within the area of the vanes that are not acted upon by
the pressure differential, the stator parts which late-
rally delimit the operating space are slightly chamfered
in thr dirwtivw Cvkdocls Lhe axis of rwtdtiun str ~s to
extend the operating space. These chamferings are carried
a little farther on both sides than confiorms to the axial
mobility of the rotor in the stator so that, when the vane
cell machine commences to rotate, the vanes emerging due
to the centrifugal force bring about an immediate cente-
ring of the rotor relative to the operating space and
this is retained because of lacking axial forces also wi-
thout any additional friction on the vanes.
In a special construction according to the invention of
the vane cell machine, the rotor is constructed so as to
be tubular and possesses a longitudinal bore in which an
even number of vane slots terminate openly and in which,
the in each case diametrically opposed vanes are rigidly
interconnected or of one-piece construction.
However, alternatively to this, the rotor can, when of
tubular construction, also receive in the tube apertures
a stator pivot which is hollow on the inside and, within
the area of the slots passing through the rotor for the
displaceable vanes, possesses a window and in which the
vanes andlor the rotor slots possess radial recesses. This
Corm of construction makes d partial balance of the radial
hydraulic fortes on the rotr possible.
By preference, the rotor, at its front ends, is coupled
to an axially fixated shaft as drive connection or as power
takeoff connection, in whit case the shaft is accommodated
in the stator frame.
APR 7 '95 02:51 +49 40 352415 PAGE.015
07-RPR-1995 07:55 RICHTER & PRRTNER +49 40 352415 5.16
_ 15
Thus, preferably within the filling area of the delivery
ceELs, the stator bore is executed acroe~ the area which
passes through the maximal radial deflection of the vanes
radially towards thQ outside in a pitch circlC so that,
by means of the recess provided hereby, a communication
of two ar more delivery cells exists. This sm p facili-
tates the filling of the delivery cells.
Furthermore, the stator frame transitional area between two
delivery cells is by preference concentrically disposed
with regard to the axis of rotation so that the vanes,
when rotating in this area acted upon by a pressure dif-
ferential, do not execute any radial movement.
According to a further canstrurtion, the outer shell of
the inner stator possesses depressions which can be acted
upon by tha p«mp del.ivery pressure or by the input pres-
sure of the motor for the at least partial compensation of
the radial hydraulic bearing load. By means of this con-
structivnaLLy simply effected step it is possible to dis-
pense with a ~turdsly dimensioned mounting or support.
The rotor portions which project over the vane operating
area preferably possess a reduced external diameter in
comparison with the rotor diameter in the vane operating
area. Hereby the rotor is axiaEly centered during the ope-
ration.
When the rotor is inoperative, the vanes sink into the
rotor slots. which may result in an axial displacement of
the rotor that does not possess a reduced external diame-
ter. In order to pre~ant, when the rotor is restarted,
that the vanes become wedged outside their operating area
with the stator inner shell, thQ stator shell which late-
ratly delimits the vane operating area, within the area
of tha non-pressurized vanos, is sonically configured so
RPR 7 '95 02:52 +49 40 352415 PRGE.016
07-RPR-1995 07:55 RICHTER & PRRTNER +49 40 352415 S.17
- 1~ - ~~~J~~~
that the vanes slide constrainedly guided into the axially
centered position when starting up.
According to a further embodiment, the rotor is connected
direct or by means of a coupling on the front side Located
opposite the intake aperture to a shaft in the form of a
drive or power- take-off means, the shafit being sealingly
inserted into the stator shell.
BRIEF DESCRIPTION OF THE pRAWINGS
Embodiment examples of the invention are explained below
with the aid of the drawings. This
F i g. 1 shows a vertical section through a vane cell
machine,
F i g. ~ shows a verticalsection in the direction of
Line II - II in Fig. 1;
F i g. 3 shows a partial view of a Longitudinal section
through a vane cell machine with canically con-
figured transitional areas between the Vane
operational area and the adjacent stator frame;
F i g. ~+ shows a sectional view through a vane cell ma-
chine having a tubular rotor, whose diametri-
cally opposed vanes are interconnected;
F i g. 5 shows a vertical section in the direction of
Line V - V in Fig. 4;
F i g. 6' shoos a sectional vicw of a vane cell machine
with a rotor possessing a concentric bore into
which a stator pivot is fitted;
F i g. 7 shows a vertical section in the direction of
Line VII - UII in Fig. 6;
RPR 7 '95 02:52 +49 40 352415 PRGE.017
07-APR-1995 07:56 RICHTER & PARTNER +49 40 352415 S.18
- 2143r119~
1~ -
F i g. 8 shows an embodiment in which the concentric sta-
tor to the intake connection is constructed, in a
vertical section;
F i g. 9 shows a vertical section in the direction of
dine IX - IX in Fig. $;
F i g. 10 shows a longitudinal cross-section of a further
embodiment of a vane cell machine, and
F i g. 11 shows a cross-section at the level of the vane ope-
rating area vertically to the section as per
Fig. 10,
F i g. 1Z shows a vertical section through the vane cell
maehine~ and
F i g. i3 shows a vertical section in the direction of
Line XIII - XII in Fig. 12.
DETAILED i)ESCRIpTION OF THE INVENTION AND THE BEST WAY OF
REALIZING THE INVENTION
The vane tell machine is preferably constructed in the form
of a single-strske vane pump which, in the embvdimenC slnourn
in the Figs. 1 and Z, is in the form of a pump, possesses
a shaftless rotor 1 whivh, in the axial direction may possess
either an external diameter 2 with a uniform circumference
as irr the vane operating area 15, or a circumference 3 redu-
ced in contrast thereto. Outside the vane operating area, the
rotor 1 is fitted into a stator 4 so as to be sealingly sup-
ported. Within this fitting-in area the stator possesses re-
cesses 5 which, according to their position arid size, are
constructed in such a way that the operating pressure of the
liquid acting herein results in a partial or complete hydrau-
lic force balance also when taking the frictional and weight
related forces into consideration. In the embodiment depicted
APR 7 '95 02:53 +49 40 352415 PRGE.018
07-RPR-1995 07:56 RICHTER & PRRTNER +49 40 352415 5.19
~~ ~ 214371
in Fig. 2, the recesses 5, when viewed in the axial direc-
tion, arc disposed in front of on t~ehind the vane operating
area 75 and symmetrically thereto.
The vertical front end areas or spacing differences b in
diameter difference existing in the top half of Fig. 2
of the rotor 9 serve at the same time for the centering of
the rotor, whereby, in operation, an the front end, equal
gaps 7 result between the rotor front end and the, in each
case, oppositely located stator front end. In the rotors
extended with reduced diameters which are otherwise freely
movable, these diameter differences 6 serve to center the
rotor relative to the operating space, in which connection
the previously described disadvantage of the unilaterally
greater effectiveness of the hydraulic pressure by bearing
against the opposite side is acceptable since the front
end area 6 in the form of an effective area is kept small
by means of a slight difference in diameter. By means ~f
this centering of the rotor relative to the operating
space, betNeen the front end areas of the rotor 1 and the
stator 4 on both sides, the gaps 7 fore hydrostatic force
compensation at the camp pressure are ensured_
The rotor 1 possesses slats 8, each of which proceeds ra-
dially, in which the vanes 9 are slidingly guided. The
space in the guide scats 8 underneath the vanes 9 communi-
cates in each case with the vane cell located in front of
the same in the direction of rotation, in the present case
by means of radial recesses '10 on the vane andlor recesses
91 in the rotor. Since, in the inoperative state of the
vane cell machine, as depicted in Fig. 3, the vanes 9,
which, in operation, are moved outwardly by centrifugal
force, can be immersed in the rotor and the freely movable
rotor 1, whose diameter has not been reduced, may be dis-
placed axially on one side against the front end of the
APR 7 '95 02:53 +49 40 352415 PRGE.019
07-RPR-1995 07:56 RICHTER & PRRThIER +49 40 352415 5.20
- 19 --
stator 4, whereby, when the vane cell machine is started
up, the vanes9 are prevented from emerging, which may lead
to as much as a wedging of the Vanes on the stator inner
wall in question; within the area of the vanes 4 which are
not acted upon by differential pressure, the stator inner
frame components 12 Laterally delimiting the operating
space are constructed in the direction towards the axis
of rotation so as to be conical ar slightly r.hamfered,
thus expanding the working space. These conical or chamfe~
red stator inner frame compnnpnts 12 do extend on both ~i-
des insignificantly farther than conforms with the axial
mobility of the rotor 1 in the stator so that, with the
start of rotation of the vane cell machine, the vanes
emerging d~.ie to centrifugal force immcdiatcLy bring about
a centering of the rotor 1 relative to the operating space
15 and the same is retained in tht case of lacki~ig axial
forces also without any additional friction on the vanes
g,
fhe drive and power take-off connection of the vane cell
machine is effected by means of a shaft 13 projecting into
the stator frame 4 and seated there, which is connected by
means of a coupling 14 with the rotor in a non-interacting
manner.
In the alternative embodiment according to the Figs. b and
7, the rotor 1 is of tubular constructi~nr in which case
a stator pivot 16 projects concentrically into the tube
aperture. the stator pivot 96 hPing rigidly connected with
the other stator components, ey means of this construction
the hydraulic operai-ing pressure within the area of the
tube slots does not become effective an the rotor. The re~-
maining hydraulic fortes and thQ radial farces given ri3e
to both by weight and friction are partially or completely
compensated by means of recesses 17 acted upon by the
I
RPR 7 '95 02:,53 +49 40 352415 PAGE.020
07-RPR-1995 07:57 RICHTER & PARTNER +49 40 352415 5.21
2~1~3'~1~
_ ZQ _
hydraulic operating pressure on the surface of the con-
centric stator pivot 16 in pumps in the area of the nar-
rowing vane Cells and in motors in the area of the ex-
panding vane cells in denenriance U~1011 the size and the
position of the recesses.
whereas in the embodiments described in the foregoing
the filling of the expanding vane cells takes place sub-
stantially tangentially from the outside, in the embodi-
ment depicted in the Figs. 8 and 9, an intake connection
is provided on the stator pivot 16 Which is constructed
so as to be hollow up to the end of the operating space
width 2Q.. This stator is provided with a window in the
operating area 15 of the expanding vanes 9, in which case;
in the vanes 9 and./or in the rotor 1, radial recesses. 10
and 11 ars provided, through which the expanding vane
w ells' are filled with the assistance of the centrifugal
force. The recesses 10 and 11, when viewed in the direc-
tion of rotation, are located on the rear of the vanes
and/or in the rotor immediately behind the vanes.
The vane pump depicted in the Figs. 10 and 11 is, substan-
tially comprised of a rotor 919 mounted on a hollow shaft
110 i~~the forrti of an inner.frame 100, which is disposed,
so as to be rotatable and surrounded by the latter in its
stator 112. The stator 112 may - as can be gathered from
the Fig. 10 -- be of two-piece construction, more particu-
larly with a structural element 113 integrated with the
hollow ~h~aft 11Q. The rotor 919 p~ssrssrs, outside tire
operating area determined by the vanes 124 Cfig. 10), in
each case lateratly frm~ these, a reduced diameter and,
with it-s outer shell surface, bears sealingly against the
stator innrr~ shell. In each case, between the front ends
114 and 115 of the rotor, a gap 116 or 117 is formed re~-
lative to the o~ruvsitely located front end of the stator,
RPR 7 '95 02:54 +49 40 352415 PAGE.021
07-RPR-1995 07:57 RICHTER & PRRTNER +49 40 352415 S.22
- - 21 - 2143X9
which is pressurized. By way of example, a~ axial bore
118 and a radial bare 118' ensure.a pressure equalization
between the gaps 116 and 117. On the drive side and on
the power take-off side, the rotor is connected either
direct or by means of a non-depicted coupling, with a
shaft 119 which is supported so as to be sealed in the
stator frame or rotatably in the drive or in the power
take-off means. The hollow shaft 11Q is constructed in
the form of a front-end intake aperture which is ac-
cessible in the direction of the arrow 12E} which commu-
nicates via a window opening 121 of the hollow shaft by
means of pertinent recPSCes of the rotor with radialLy
extending groove-like recesses 112 in the rotor and re-
rPSSes 173 in the vanes_ The vanes 124 are Located in
radial slots 1Z5 of the rotor 111. The inner shell 100
is provided with depressions 126 on its running surface,
which are acted upon hydraulically by the pump delivery
pressure of the motor and, in size and position, are dis-
posed in such a way that the radial hydraulic bearing
load is partially or compCetely compensated.
The space located between the rotor 111 and the stator
112 with the crescent-shaped delivery cells 127 is in
each case subdivided by vanes 124, which rotate within
the area depicted with the arch 128 with the respective
vane end. Over and above that, the stator inner shell
possesses additional recesses 129 which project in a
crescent-Like fashion over the maximal radial deflection
(curve 128).
F3Ptween an expanding and a narrowing delivery cell 127,
a transfer area 130 is provided, wherein the vanes 124,
when rotating in the direction of the arrow 131, do
not execute a radiaC movement.
RPR 7 '95 02:54 +49 40 352415 PRGE.022
07-RPR-1995 07~58 RICHTER & PRRTNER +49 40 352415 S.23
2~4~'~I~
_ 22 _
The vane cell machine according to the Figs. 'IO and 11
functions ac rtptailed below.
The liquid which streams in the direction of the arrow
92U is conducted via the window opening 921 into the
groove-like radial recesses 122, 123 radially outwardly
into the delivery cells 12r' and is substantially tangen-
tially conducted away in the direction of the arrow 132.
The intake of the liquid through the hollow axis and the
filling of the expanding vane cells from the inside to
the outside is effected in pumps very largely by the
energy supply from the drive and, even at high rotational
speeds, Leads to low net positive suction heads. It is
at the same time possible to provide a hydraulic compen-
sation by means of simpte constructions! steps.
In the Figs. 12 and 13, based on the example of the pump,
a functionally and, from the viewpoint of production en-
gineerin~, particularly advantageous form of the equali-
zation of the tadial hydraulic compressive forces acting
upon the rotor is illu~tr~tcd.
The tubular rotor 201 is provided with friction bearings
in both supports 202 and 203. The single-stroke suction
ring 204 constitutes the operating space 20S and is ri-
gidly connected with the supports 202 and 203. this
three-piece externally cylindrical stator is inserted
with a gap 206 which carries liquid or which can be passed
through by liquid into the pump housing 207 and sealed e.g.
with the aid of sealing rings 208 at both ends relative to
the pump housing. The pressure vent 209 located in the suc-
tion ring, in the course of its passage to the pertinent
outlet connection piece 218 of the housing 207 arts upon
the gap 206 with the respective operating pressure of the
pump.
RPR 7 '95 02:55 +49 40 352415 PRGE.023
07-RPR-1995 07:58 RICHTER & PRRTNER +49 40 352415 5.24
21~3'~1~~
_ 23
Located opposite the radial hydraulic compressive farces
acting upon thp rntnr, approximately in the direction of
the Line of intersection of Fig. 12, oneor several radial
bores Z10 are disposed in the supports 2D2 and 2D3, which
allow antagonistic compressive forces within the bearing
areas to became effective upon the rotor and which tend
to a partial or complete pressure balance.
The stator frame 213 is fitted in a contactless fashion,
but with a narrow gap, into the internal diameter of the
rotor 201. Via the intake bore 21~ of the stator frame
213 which is continuous to the drive side and the window
215 within the area of the expanding vane cells, the fil-
ling of the Same is effected. The input pressure is ef-
fected via the through bore 214 and the bore Z16 on both
front ends of the rotor.
In order to restrict the hydraulic radial pressures very
largely to the operating area, i.e. the axial length of
the suction ring, the bearings, within the circumferential
effective area of the hydraulic radial compre~~ive force,
are provided with recesses 211 which, via the gap 217 and
the bores 214 and 218, communicate with the low-pressure
side so that, within the area of the recesses 211, only a
Short bearing length 212 rembins which is adequate for
sealing and support.
The hydraulic operating pressure acts through the slots
217 without constituting a load on the rotor, on the stator
frame direct and, in addition, the gap between rotor and
stator frame is acted upon by pressure via the rotor slots,
which contributes to a further partial pressure equaliza-
tion.
RPR 7 '95 02:55 +49 40 352415 PRGE.024
