AU684725B2

AU684725B2 - Vane cell machine

Info

Publication number: AU684725B2
Application number: AU49543/93A
Authority: AU
Inventors: Bernt Lorentz
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-09-02
Filing date: 1993-08-26
Publication date: 1998-01-08
Anticipated expiration: 2013-08-26
Also published as: AU4954393A; DE59302390D1; CA2143719A1; EP0659237B1; JPH08500877A; ATE137306T1; CN1103931A; CA2143719C; JP3129737B2; WO1994005912A1; DK0659237T3; CN1040786C; DE9211768U1; KR950703124A; EP0659237A1

Abstract

In order to compensate in an efficient manner the radial and axial forces in a vane cell machine, and at the same time to increase its service life, the vane cell machine for liquids has a slotted rotor (1) mounted in a stator (4), and in which radially movable vanes (9) are slidingly mounted in such a way that they can be pressed against a stator inner wall by centrifugal, elastic or other pressure forces. Expanding or narrowing sickle-shaped feeding cells are formed and the liquid enters through a hollow, central stator, so that the vane cells are filled from the inside towards the outside. The rotor (1) is tubular and designed without a shaft; its two sides are prolonged beyond the working area determined by the vanes and the rotor is mounted in the outer stator by means of its prolongations. The rotor has vane slits that extend from its inner to its outer diameter. In the area of the rotor prolongations, the casing of the stator has hydraulic working surfaces oriented towards the rotor and on whose surface the operation pressure is applied and/or not applied in order to at least partially compensate or avoid radial forces.

Description

041I DATE 29/03/94 APPLN. ID 49543/93

AO

9 JP DATE 23/06/94 PCT NUMBER PCT/EP93/02311 AU9349543 iINI M'NA I INALh LUSAMMENARBEITAUF DEM GEl3IET DES PATETWESENS (PCT) (51) Internaitionale Patentklassifikation 5 (11) Internijtionale Ver6ffentlichungsnumnier: WVO 94/05912 FO4C 2/344, 15/00, 15/02 Al (43) Internationales Veriiffentlichungsdatum: 17. Marz 1994 (17.03,94) (21) Internationales Aktcnzeichen: PCT'EP93 '02311 (22) Internationales Anmeldedatum: 26. August 1993 (26.08.93) Prioritiitsdaten: G 92 11768.6 U 2. September 1992 (02.09.92) DE (71)(72) Anmelder und Erfinder: LORENTZ, Bernt [DE/DE]; Groger Ring 9, D-22457 Hamburg (DE), (74) Anwitte: RICHTER, Joachim usw. Neuer Wall 10, D- 20354 Hamburg (DE).

(81) Bestimmungsstaaten: AT, AU, CA, CH, CZ, DE, DK, ES, FI, GB, HU, JP, KR, LU, NL, NO, PL, PT, RU, SE, SK, UA, US, europflisches Patent (AT, BE, CH, DE, DK, ES, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE).

Vcriiffentliclit Alit internationalemn Reclwrclienbcricla, Vor Ablatif der /tir ;iiderunigen der Ansprfiche zygelasseneti Frist. llerdffentlichzuig ivird ;wiederJholr ,falls indeningen eintreffen.

6804725 (54) Title: VANE CELL MACHINE (54) Bezeichnung: FLOG ELZELLENMASCH INE (57) Abstract In order to compensate in an efficient manner the radial and axial forces/ in a vane cell machine, and at the same time to increase its service life, the vane cell machint' for liquids has a slotted rotor mounted in a stator and in which radialty movable vanes are slidingly mounted in such a way that they 4 can be presse.1 against a stator inner wall by centrifugal, elastic or other pressure forces. Expanding or narrowving sickle-shaped feeding cells are formed and the -x liquid enters through a hollow, central stator, so that the vane cells are filled from the inside towards the outside. The rotor is tubular and designed without a j shaft; its two sides are prolonged beyond the working area determined by the vanes and the rotor is mounted in the outer stator by means of its prolongations. The rotor has vane slits that extend from its inner to its outer diameter. In the area of the rotor prolongations, the casing of the stator has hydraulic working surfaces oriented towards the rotor and on whose surface the operation pressure is applied and/or not applied in order to at least partially compensate or avoid radial forces.

(57) Zusamnienfassung Um bei einer Flflgelzellenmaschine einen wirkungsvollen Ausgleich der radialen und axialen Kraifte bei gleichzeitiger Erh6hung ihrer Lebensdauer zu schaffen, besteht die Fltlgelzellenmaschine fOr Flassigkeiten aus einem in einem Stator gelagerten, geschlitzten Rotor in dem radial verschiebbare Flfigel gleitend angeordnet sind, die fliehfeder- oder anders druckkraftbelastet an eine Statorinnenwand gleitgelagert pre~bar sind, wobei sichelflirmig sich erweiternde oder verengende Fdrderzellen gebildet werden und der Fl~ssigkeitseintritt durch einen hohlen, zentrischen Stator sowie die F011lung der Fitigelzellen von innen nach augen erfolgt. Der Rotor ist wellenlos und rohrf~rmig ausgebildet, beide Seiten sind Oiber den durch die FlOgel bestimmten Arbeitsbereich hinaus veriingert und mit den Verlilngerungen ist der Rotor im Augenstator gelagert, wobei der Rotor vomn Innen- zumn Augendurchmesser durchgehende Fliigelschlitze aufweist. Der Mantel des Stators weist im Bereich der Rotorverlingerungen an der Oberflche vom Betriebsdruck beaufschlagte und/oder entlastete, gegen den Rotor gerichtete hydraulische Wirkfliichen zur zumnindest teilweisen Kompensation bzw. Vermeidung radial auftretender Krafte auf.

1 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 displaceable 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 narrow in a crescent-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 ce'L machines are constructed in the form of fixed displacement pumps or fixed displacement motors or in the form of variable displacement pump or variable displacement motor.

However, vane 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 running. Problems do arise though due to the respective hydraulic radial and axial bearing loads.

The hydraulic radial bearing loads in vane cell machines possessing roto- lengths equal to the operating area of the vanes result +rom the product of the projection surface, formed 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 stator 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 WOM l I 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 fLuidics disadvantageous multi-stroke pump or motor constructions.

The hydraulic axiaL bearing Loads can be avoided by the symmetric.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 an 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 compresCor or motor related to the subject matter of the application, pneumatic pads in some of the recesses machined into the front ends of the rotor are provided according 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 Lateral 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 repellent forces in the direction of a central position.

A comparatively costly solution is Likewise proposed in the DE-A-31 20 350 for a vane ceLL machine, in which the shaft rotor is designed so as to possess two large axially displaceable bushings which are acted upon by the feed pressure in pressurized gaps in axially displaceabLe bearing bushings on the rear sides and front ends in order to bring about a 1 I I ~Ill~C~e 3 a pressure equalization on the shaft rotor so as to minimize the bearing Loads and frictional Losses. 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 t-his. 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 compensation is effected on the opposite side by means of a symmetric construction.

Moreover, rotary piston pumps are known e.g. from the DE-AS 12 36 641. There, in a stator hoLLow space of constant diameter, a cyLindricaL revoLving rotor with a pLurality of substantiaLLy radiaL sLots, in which vanes are sLiding, is supported, in which case, by means of a pertinentLy wavy configuration of the cross-sectionaL contour of the stator cavity, severaL delivery ceLLs are formed between the stator and the rotor to and from which the pumped or operating medium is suppLied 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, communicate in each case in a continuous LongitudinaL duct of the rotor aLLocated to each vane. The LongitudinaL ducts communicate in turn with an annuLar groove which communicates with the high-pressure side of the pump or the motor.

I -I I sL~- II~ 4 For the direct feeding and removal of the pumped medium it is also known to provide ducts Leading into or out from the delivery cells, which wiLL then have to communicate in turn with ducts in a stationary housing portion. The use of such rotor ducts is regarded as advantageous in as far as e.g. one or more operating space(s) exist between the rotor circumferential area and the circumferential waLL of the stator hcLLow 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 off 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 discharging ducts in the rotor so as to possess an adequate width but, on the other hand, to avoid too great a weakening of the rotor owing to the ducts and, finaLLy, to prevent an axiaL thrust from pressure ducts having an adverse effect on the pressure, it is further proposed in the DE-AS 12 36 941 that, in the form of delivery-side ducts on the respective side of each vane, several grooves be machined into the relevant wall of the associated rotor slot, in which case, 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 the delivery-side longitudinal ducts of the rotor terminate, while the annular grooves are in communication with pressure connections of the pump or of the motor. The rotor hollow space into which the Low-pressure-side bores lead, is a part of a concentric Longitudinal bore of a shaft connected to the rotor. However, this rotary piston pump is ~aa~aa~aaRI*arr~-- expensive to construct on account of the numerous radial bores also outside the vane slots as well as owing to the great number of outlets.

The US-A-3,361,076 describes a vane cell motor with a rotor supported in a stator, said rotor being slotted 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, just like the terminal piece, projects radially over the external diameter of the stator element and thereby Laterally Limits the hydraulic operating area. The accommodation for the vanes is, in the axial direction, outwardly constructed in the form of a shaft, supported on ball and roller bearing elements and sealed in the stator and caused to pass out from the vane cell motor for receiving a driving element. In this case the terminal piece possesses only a short shaft shoulder for accommcdating 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 above the slotted area which is extended to both sides having a greater external diameter for the positively Locking axial centering of a displaceable lifting ring. Both extensions are mounted by means of tapered roller bearings, also for the absorption of radial and axial forces, in the housing while the one extension is passed out of the machine in the form of a rotationally sealed shaft for the drive connection. Pressure-adjustable overflow valves limit the gap pressure within the gap areas arising due to leakage caused by the operating pressure which, at the same pressure via these gap areas up to the seal diameter, brings about a pressure equalization. The axial hydraulic forces across the non-pressure-equalized surface area below the sealing diameter are absorbed by the bearings. In this vane cell motor the vanes are spring-Loaded, whereby a high

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6 degree of proneness exists in so far as, when the spring pressure faLLs off, it is no Longer ensured that, in the operative state, it will 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 such a way that a retracting of the vanes into their receiving 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 shaftLess nor in a tubular manner, which does not possess a vane slot which is continuous from the internal to the external diameter since the internal diameter is formed by the flow sleeve. The pressurized space of the stator does not contribute within the area of the rotor extensions to the compensation of radial forces which, from the operating pressure, 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 sealing 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, pertinent 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 cell pump, effective surface areas acted upon by operating pressure and directed against the rotor are provided in I- I I I L~ -ae 7 the stator. For the compensation of radial hydraulic forces 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 in this vane pump that additional gap entry edges acted upon by operating pressure and possessing relatively short gap lengths and that thereby the efficiency is impaired by increased volumetric losses.

Moreover, the formation of hydrodynamic pressure supporting surfaces is prevents to a very large extent since the narrow gaps necessary for this within the supporting bearing area are eliminated by the effective areas acted upon by operating pressure which are planned at this point.

According to the FR-A-13 95 435, a vane cell machine is known, in which, in a stator, a shaft-journalled rotor rotates, wherein the inner shell surface of the stator possesses 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 proceeding guide slots for four vanes, in which case the disposition of the guide slots is such that two oppositely located guide slots each are, relative to a theoretical radius line, are reciprocally staggered with the result that only one vane each comes to be lie in each individual pitch-circular recess. A slide or journal bearing lubricated by delivery liquid of the rotor shaft is not provided in this case.

The DE-A-2 022 841 describes a valveless 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 e ILI I IL~ II~BIIY ~sllll~ 8 eccentricaLLy supported in the pump casing in such a way that, within the operating area, an adequate delivery cross-sectionremains between the hoLLow shaft and the casing 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, while the hollow shaft is supported 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 Liquids, which are empLoyed in the form of delivery pumps, an operation for liquids with elevated vapor pressure and without a positive supply feed owing to the net positive suction head rapidly ring with the rotational speed, an operation -1 with economic drive speeds of e.g. 1450 min and higher is no Longer possibLe.

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 presupposition 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, sLowly rotating pumps with a correspondingLy great cyclic pump volume and pump Lengths possess poorer volumetric degrees of effectiveness and a Lower dry intake capacity 9 1 P \OPERDH9543 IRES 199(97 -9than rapidly rotating pumps with a correspondingly smaller cyclic pump volume and gap lengths. These technical connections 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 capacity.

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 discharge 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 deterioration of the net positive suction head.

In accordance with the present invention, there is provided a vane cell machine for liquids, comprising a rotor mounted in a stator, having radial guide slots in which radially displaceable vanes are glidingly disposed, for urging against an inner surface of a frame of the stator, in the course of which, while the rotor is revolving, delivery cells are formed which expend or narrow in a crescent-like fashion and the entry of liquid into the cells takes place through an inner stator arranged concentrically within the rotor, wherein a) the rotor is shaftlessly and tubularly constructed with radial guide slots which are continuous from an internal to an external diameter thereof, said rotor extending across an operating area defined by movement of the vanes and possessing a reduced diameter within the operating area; b) rotor extensions are provided on both sides of the operating area and are 25 supported in friction bearings in the stator; c) the rotor is supported on the concentrically arranged inner stator over the length of the rotor; and d) the frame of the stator, adjacent the extensions of the rotor, is arranged to receive hydraulic pressure relief from forces generated by the rotor.

'dl 1~P" P.OPERDHW9543 RES 1997 Preferably, at least one bore is provided in the inner stator for transmitting supply pressure into a bearing gap between the rotor and the stator for providing said pressure relief.

Preferably, the rotor is provided with a longitudinal rotor bore, from which groove-like, radial recesses extend into the delivery cells, wherein the groove-like radial recesses are formed for filling the delivery cells in the vanes and/or are formed in the vane slots, wherein the liquid enters the delivery cells in the radial direction through a window in the rotor and said radial recesses in the rotor and/or in the vanes.

Preferably, the rotor is arranged so as to be sealingly mounted in the stator, and wherein the stator is provided with recesses which are disposed in the stator frame, outside the operating area, so as to be located opposite the rotor and/or disposed in a casing of the inner stator, which engages through a concentric aperture of the rotor and bears against the same in a sealing manner.

Preferably, outside the operating area, the rotor is fitted tightly so as to be sealingly mounted in the stator and the stator possesses recesses which are acted upon by the operating pressure of liquid provided to the machine for creating an hydraulic seal.

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-that the -vano sJl de .On t- ain.e... -14 ded Fite t..he a x I I centered position when starting up.

According to a further embodiment, th tor is connected direct or by means of a cou -g on the front side Located opposite the intake erture to a shaft in the form of a drive or r take-off means, the shaft being sealingly nt Q t- he stator she.l BRIEF DESCRIPTION OF THE DRAWINGS Embodiment examples of the invention are explained below with the aid of the drawings. This F i g. 1 F i g. 2 F i g. 3 F i g. 4 shows a vertical section through a vane cell machine; shows a verticalsection in the direction of Line II II in Fig. 1; shows a prtial view of a longitudinal section through a vane cell machine with conically configured transitional areas between the vane operational area and the adjacent stator frame; shows a sectional view through a vane cell machine having a tubular rotor, whose diametrically 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 F i g. 7 shows a sectional view of a vane cell machine with a rotor possessing a concentric bore into which a stator pivot is fitted; shows a vertical section in the direction of Line VII VII in Fig. 6; L I _1 II_ I r(l~ab"L~c~ It 111 9 a rr F i g. 8 F i g. 9 F i g. 10 F i g. 11 F i g. 12 F i g. 13 shows an embodiment in which the concentric stator to the intake connection is constructed, in a vertical section; shows a vertical section in the direction of Line IX IX in Fig. 8; shows a Longitudinal cross-section of a further embodiment of a vane ceLL machine, and shows a cross-section at the Level of the vane operating area vertically to the section as per Fig. shows a vertical section through the vane cell machine, and shows a vertical section in the direction of Line XIII XII in Fig. 12.

DETAILED DESCRIPTION OF THE INVENTION AND THE BEST WAY OF REALIZING THE INVENTION The vane cell machine is preferably constructed in the form of a single-strike vane pump which, in the embodiment shown in the Figs. 1 and 2, is in the form of a ptvnp, possesses a shaftless rotor 1 which, in the axial direction may possess either an external diameter 2 with a uniform circumference a in the vane operating area 15, or a circumference 3 reduced in contrast thereto. Outside the vane operating area, the rotor 1 is fitted into a stator 4 so as to be sealingly supported. Within this fittirg-in area the stator possesses recesses 5 which, according to their position and size, are constructed in such a way that the operating pressure of the liquid acting herein results in a partial or complete hydraulic force balance also when taking the frictional and weightrelated forces into consideration. In the embodiment depicted 0 P~'4'2 i ~PP~4il II -r I I 13 in Fig. 2, the recesses 5, when viewed in the axial direction, are disposed in front of or behind the vane operating area 15 and symmetrically thereto.

The vertical front end areas or spacing differences 6 in diameter difference existing in the top half of Fig. 2 of the rotor 1 serve at the same time for the centering of the rotor, whereby, in operation, on 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 of this centering of the rotor relative to the operating space, between the front end areas of the rotor 1 and the stator 4 on both sides, the gaps 7 fora hydrostatic force compensation at the same pressure are ensured.

The rotor 1 possesses slots 8, each of which proceeds radially, in which the vanes 9 are slidingly guided. The space in the guide slots 8 underneath the vanes 9 communicates 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 and/or recesses 11 in the rotor. Since, in the inoperative state of the vane cell machine, as depicted in Fig. 3, the vanes 9, whic,, 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 displaced axially on one side against the front end of the 4o 1fe C) L£r I~B~PIIIC II IILA IL 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 9 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 or slightly chamfered, thus expanding the working space. These conical or chamfered stator inner frame components 12 do extend on both sides 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 due to centrifugal force immediately bring about a centering of the rotor 1 relative to the operating space and the same is retained in the case of lacking axial forces also without any additional friction on the vanes 9.

The 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 sealed 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. 6 and 7, the rotor 1 is of tubular construction, in which case a stator pivot 16 projects concentrically into the tube aperture, the stator pivot 16 being rigidly connected with the other stator components. By means of this construction, the hydraulic operating pressure within the area of the tube slots does not become effective on the rotor. The remaining hydraulic forces and the radial forces given rise to both by weight and friction are partially or completely compensated by means of recesses 17 acted upon by the I I L~ I 'I~BII~P 1< hydraulic operating pressure on the surface of the concentric stator pivot 16 in pumps in the area of the narrowing vane cells and in motors in the area of the expanding vane cells in dependence upon 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 substantially tangentially from the outside, in the embodiment 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 20. 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 and 11 are provided, through which the expanding vane cells are filled with the assistance of the centrifugal force. The recesses 10 and 11, when viewed in the direction 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 substantially comprised of a rotor 111 mounted on a hollow shaft 110 in the form 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 particularly with a structural element 113 integrated with the hollow shaft 110. The rotor 111 possesses, outside the operating area determined by the vanes 124 (fig. 10), in each case laterally from these, a reduced diameter and, with its outer shell surface, bears sealingly against the stator inner shell. In each case, between the front ends 114 and 115 of the rotor, a gap 116 or 117 is formed relative to the oppositely located front end of the stator,

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_7 ;At< V 0r^ gRe~B--- I I 11- which is pressurized. By way of example, an axial bore 118 and a radial bore 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 110 is constructed in the form of a front-end intake aperture which is accessible in the direction of the arrow 120 which communicates via a window opening 121 of the hollow shaft by means of pertinent recesses of the rotor with radially extending groove-Like recesses 112 in the rotor and recesses 123 in the vanes. The vanes 124 are located in radial slots 125 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 disposed in such a way that the radial hydraulic bearing load is partially or completely 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), Between 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 c radial movement.

I IBs I ~e 17 The vane cell machine according to the Figs. 10 and 11 functions as detailed below.

The Liquid which streams in the direction of the arrow 120 is conducted via the window opening 121 into the groove-Like radiaL recesses 122, 123 radiaLLy outwardly into the deLivery ceLLs 127 and is substantiaLLy tangentially 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 compensation by means of simple constructionaL steps.

In the Figs. 12 and 13, based on the exampLe of the pump, a functionaLLy and, from the viewpoint of production engineering, particuLarLy advantageous form of the equalization of the tadiaL hydrauLic compressive forces acting upon the rotor is iLLustrated.

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 205 and is rigidly 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 suction ring, in the course of its passage to the pertinent outLet connection piece 218 of the housing 207 acts upon the gap 206 with the respective operating pressure of the pump.

ar- 9 I I I I Located opposite the radial hydraulic compressive forces acting upon the rotor, approximately in the direction of the Line of intersection of Fig. 12, one or several radial bores 210 are disposed in the supports 202 and 203, which allow antagonistic compressive forces within the bearing areas to become effective upon the rotor and which lead 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 214 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 filling of the same is effected. The input pressure is effected via the through bore 214 and the bore 216 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 compressive forces, 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 remains 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 equalization.

71 Vr o -rs~ II--r

Claims

1. Vane cell machi e for liquids, comprising a rotor mounted in a stator, having radial guide slots in which radially displaceable vanes are glidingly disposed, for urging against an inner surface of a frame of the stator, in the course of which, while the rotor is revolving, delivery cells are formed which expend or narrow in a crescent-like fashion and the entry cf liquid into the cells takes place through an inner stator arranged concentrically within the rotor, wherein a) the rotor is shaftlessly and tubularly constructed with radial guide slots which are continuous from an internal to an external diameter thereof, said rotor extending across an operating area defined by movement of the vanes and possessing a reduced diameter within the operating area; b) rotor extensions are provided on both sides of the operating area and are supported in friction bearings in the stator; c) the rotor is supported on the concentrically arranged inner stator over the length of the rotor; and d) the frame of the stator, adjacent the extensions of the rotor, is arranged to receive hydraulic pressure relief from forces generated by the rotor.

2. Vane cell machine according to claim 1, wherein at least one bore is orovided in the inner stator for transmitting supply pressure into a bearing gap between the rotor and the stator for providing said pressure relief.

3. Vane cell machine according to either claim 1 or 2, wherein the rotor is provided with 25 a longitudinal rotor bore, from which groove-like, radial recesses extend into the delivery cells, wherein the groove-like radial recesses are formed for filling the delivery cells in the vanes and/or are formed in the vane slots, wherein the liquid enters the delivery cells in the radial direction through a window in the rotor and said radial recesses in the rotor and/or in the vanes. I I L IL L I P OI'R~DHSA9543.RES 191 r

4. Vane cell machine according to any one of claims 1 to 3, wherein the rotor is arranged so as to be sealingly mounted in the stator, and wherein the stator is provided with recesses which are disposed in the stator frame, outside the operating area, so as to be located opposite the rotor and/or disposed in a casing of the inner stator, which engages through a concentric aperture of the rotor and bears against the same in a sealing manner.

Vane cell machine according to any of claims 1 to 3, wherein outside the operating area, the rotor is fitted tightly so as to be sealingly mounted in the stator and the stator possesses recesses which are acted upon by the operating pressure of liquid provided to the machine for creating an hydraulic seal.

6. Vane cell machine according to any one of claims I to 5, wherein a portion of the rotor outside the operating area possesses an identical or a reduced external diameter in comparison with its diameier within the operating area.

7. Vane cell machine according to any one of claims 1 to 6, wherein the stator frame which laterally delimits the vane operating area is conically configured or provided with chamfers so as to expand the operating area.

8. Vane cell machine according to any of claims 1 to 7, wherein the rotor includes an even number of vane slots in which diametrically opposed vanes are each rigidly interconnected or of one-piece construction.

9. Vane cell machine according to any one of claims 1 to 8, wherein the inner stator is 25 hollow and, within the region of slots for the radially displaceable vanes, possesses a window for liquid to pass thersthrough into the delivery cells.

Vane cell machine according to any one of claims 1 to 9, wherein the extensions are fitted into the surrounding stator so as to be readily rotatable and in that the stator, on both ST 77 30 sides of the operating area, adjacent the rotor extensions possesses recesses acted upon by II -I -sn I 111p19 ~PIIII C I-qC -1 I I P OPER'DH49543 RES l9V-99 S S S S *5*S S.. 55 S -21- hydraulic pressure in such a way that the radial hydraulic or weigh-: elated forces of the rotor are partially or fully compensated.

11. Vane cell machine according to any one of claims 1 to 10, wherein the rotor is coupled to an axially fixed shaft in the form of a power drive or power take-off connection.

12. Vane cell machine according to any of claims 1 to 11, wherein the entry of liquid into the cells through the inner stator is effected during maximal outward radial deflection of the vanes so that, by means of a recess provided in the ftator, a connection of two or more delivery cells exists.

13. Vane cell machine according to any one of claims 1 to 12, wherein a transitional region of the stator frame, between the expanding and the narrowing delivery cells is configured so that the vanes, when rotating in this transitional region, do not execute any 15 radial movement.

14. Vane cell machine according to any one of claims 1 to 13, wherein the inner stator possesses depressions for the at least partial compensation of the radial or axial hydraulic bearing load of the rotor.

Vane cell machine according to any one of claims 1 to 14, characterised in that the stator frame, which laterally delimits the vane operating area is of conical construction within an area in which the vanes are not acted upon by pressure.

16. Vane cell machine according to any one of claims 1 to 15, wherein the gaps between the stator and ends of the rotor are pressure-compensated by means of a hydraulic connection.

17. Vane cell machine according to any one of claims 1 to 16, wherein the stator is inserted in a pump housing which includes a suction ring with a pressure outlet on both sides rigidly connected to a bearing in the form of a cylindrical unit inserted into the housing and I I- II Psarrrrr P OpERDH\49543 IRES- 1919,97 -22- sealed at both ends relative to the housing and the stator.

18. Vane cell machine according to claim 17, wherein the cylindrical unit possesses a diameter smaller than an inner diameter of the housing so that the entire circumference is acted upon by operating pressure from the pressure outlet of the suction ring.

19. Vane cell machine according to claim 17 or 18, wherein located approximately opposite radial hydraulic pressure forces exerted by the rotor, one or more radial bores are disposed in the bearings, for hydraulic pressure compensation.

Vane cell machine according to any of claims 1 to 19, wherein the inner stator is fitted in a contactless fashion, with a narrow gap, into the internal diameter of the rotor.

21. Vane cell machine substantially as hereinbefore described with reference to the 15 accompanying drawings. .o Dated this 19th day of September 1997 20 BERNT LORENTZ By its Patent Attorneys DAVIES COLLISON CAVE V o *E I I I