EP0848165B1 - Internal gear pump - Google Patents

Abstract

The pump has a non-turnable bearing ring (4) in a bore (15) of its housing (1). The ring is pivoted relative to the bore about a pivot axis (16,17), which is parallel to its axis. The pivot axis is positioned, so that the bearing ring section facing the non-meshing part (E) of the internally geared wheel (3) is moved approximately radially towards the pinion axis by the pressure forces acting on the internally geared wheel in the pressure chamber (D). The pivot axis is formed by a housing-fastened bearing pin (16). The jacket surface of the pin is partially located in an axial groove (17) of the bearing ring jacket.

Description

The invention relates to a filler-less Internal gear machine with the features according to the Preamble of claim 1.

In a known internal gear machine of this type (DE 195 17 296 A1) is the bearing ring in which the ring gear rotates, in a housing bore with a radial clearance of approximately 0.2 mm added. To the extent of this radial play is the Bearing ring movable across its axis, but through a Stud screw on the suction side of the housing is arranged, prevented from rotating. On the The pressure side is a flat one in the wall of the housing bore Recess formed in a number of pressure fields is defined by radial openings in the bearing ring as well as radial breakthroughs of the ring gear with the pressure chamber the teeth are connected.

The pressure forces prevailing in the pressure space of the gearing act so that the ring gear is removed from the pinion is looking for. As a result, there is a tendency for delimitation of the pressure chamber from the suction chamber existing sealing contact between the tooth tips of pinion and ring gear in the non-meshing ring gear area in which the pinion teeth practically completely from the tooth gaps of the ring gear leaked, decreased or lost entirely. This However, the slope created by the pressure fields acts Opposing compressive force through which the bearing ring and together with this the ring gear as part of the available radial play is shifted towards the suction side. Because of this mobility of the bearing ring with the ring gear becomes proportional to that on the print side Pressure of the sealing contact between the tooth heads of the pinion and ring gear maintained.

The formation of pressure fields in a recess of the Housing and their connection to the pressure chamber of the Gearing is relatively complex and therefore increases the Manufacturing cost of the internal gear machine. Furthermore form those provided on the pressure side in the bearing ring Breakthroughs over which the pressure fields with pressure are subjected to stress and Deformation of the bearing ring an inhomogeneity that the Circulation of the ring gear in the bearing ring can impair.

The object of the invention is therefore a To create internal gear machine of this type, which at perfect function is more simple.

According to the invention, this object is achieved by Design of the generic internal gear machine according to the characteristic of claim 1.

This is also the case with the internal gear machine according to the invention Bearing ring with a radial clearance (for example of 0.2 mm) accommodated in the housing bore, but not in it movable, but about an axis-parallel pivot axis swiveling within the housing bore. The pivot axis is laid so that on the one hand the non-invasive Ring section assigned to the ring gear region - and thus the non-intrusive ring gear area itself - at the Pivotal movement of the bearing ring is as radial as possible moved with respect to the pinion axis. This will make the Toothed heads of pinion and ring gear in non-meshing Ring gear area acted against each other for sealing contact. Such a direction of movement is best achieved when the pivot axis with respect to the non-invasive Ring gear area roughly approximated by a right angle the circumference is offset. On the other hand, the Pivot axis but also with respect to the resulting R the hydraulic forces in the pressure chamber are that this generates a torque about the pivot axis, which is the approximation of the tooth tips of pinion and ring gear in the non-meshing ring gear area. The cheapest Position for the swivel axis is thus on the side of the Pressure space between the line of the resultant R the hydraulic forces and the non-invasive Ring section of the bearing ring assigned to the ring gear region, with particular preference the pivot axis of the line of Resulting R closer than that of the non-invasive Ring section associated ring gear region.

In contrast to the known one described at the beginning Internal gear machine is therefore not required on the Bearing ring acting pressure field through which the bearing ring together with the ring gear against those in the pressure chamber prevailing forces is supported by the Gearing geometry given sealing contact of the tooth tips in the non-intrusive ring gear area. Rather, the pressure forces prevailing in the pressure chamber even used the ring around the bearing ring to pivot the pivot axis so that the non-intrusive Ring gear area tracked and proportional to the size of the prevailing pressure forces the sealing contact is maintained.

The pivot bearing of the bearing ring is different Realizable, for example, by the bearing ring self-provided bearing journals, which in corresponding Engage recesses in the housing. More advantageous and However, a pivot bearing of the bearing ring is easier by a bearing pin fixed in the housing, which with a Part of its peripheral surface as a bearing surface in an axial groove is on the outer circumference of the bearing ring. Because the bearing ring through the forces prevailing in the pressure chamber at the above as expediently described embodiment with the axial groove is pressed against the bearing pin is the Partially cylindrical axial groove in its dimensions on the Bearing pin matched so that it is as uniform as possible Surface pressure occurs. The bearing pin prevents at the same time a rotation of the bearing ring in the housing bore.

The internal gear machine described can be in one simple embodiment be designed so that pinion, Ring gear and bearing ring with their respective end faces seal directly against the housing walls. However can improve efficiency in known Way axial washers are provided by pressure fields in sealing contact with the end faces of at least pinion and ring gear are held. The pressure fields can be in the Housing walls and / or in the teeth end faces of the axial disks formed his.

A further increase in the efficiency of the Internal gear machine according to the invention, in which Axial disks are provided, can then be achieved if ensured by an appropriate construction is that the thrust washers together with the bearing ring and the ring gear the desired compensation movement for the Maintaining the sealing contact between the tooth heads can execute. Because this ensures that the Control of the hydraulic pressure conditions in the pressure or. Suction chamber, which in a known manner by control or Pre-filling slots in the axial washers are made independently optimally from the movements of the ring gear and the bearing ring remains.

Fig. 1 eine erste Ausführungsform im Querschnitt längs der Linie I-I in Fig. 2;

Fig. 2 einen Axialschnitt längs der Linie II-II in Fig. 1;

Fig. 3 eine zweite Ausführungsform im Querschnitt längs der Linie III-III in Fig. 4;

Fig. 4 einen Axialschnitt längs der Linie IV-IV in Fig. 3;

Fig. 5 eine Innenansicht des Gehäusedeckels, geschnitten längs der Linie V-V in Fig. 4, mit einer Darstellung der zugeordneten Axialscheibe;

Fig. 6 eine dritte Ausführungsform in einem Axialschnitt analog zu Fig. 4;

Fig. 7 eine Innenansicht des Gehäusedeckels, geschnitten längs der Linie VII-VII in Fig. 6, entsprechend Fig. 5;

Fig. 8 eine vierte Ausführungsform in einem Axialschnitt analog zu Fig. 4;

Fig. 9 einen Fig. 5 entsprechenden Querschnitt längs der Linie IX-IX in Fig. 8;

Fig. 10 eine fünfte Ausführungsform im Querschnitt längs der Linie X-X in Fig. 11;

Fig. 11 einen Axialschnitt längs der Linie XI-XI in Fig. 10;

Fig. 12 einen Fig. 5 entsprechenden Querschnitt längs der Linie XII-XII in Fig. 11;

Fig. 13 eine sechste Ausführungsform im Querschnitt längs der Linie XIII-XIII in Fig. 14;

Fig. 14 einen Axialschnitt längs der Linie XIV-XIV in Fig. 13;

Fig. 15 einen Fig. 5 entsprechenden Querschnitt längs der Linie XV-XV in Fig. 14;

Fig. 16 eine siebte Ausführungsform im Querschnitt längs der Linie XVI-XVI in Fig. 17;

Fig. 17 einen Axialschnitt längs der Linie XVII-XVII in Fig. 16, und

Fig. 18 einen der Fig. 5 entsprechenden Querschnitt längs der Linie XVIII-XVIII in Fig. 17.

Further advantages and features of the invention result from the following description of exemplary embodiments with reference to the accompanying drawings. The drawings show:

Figure 1 shows a first embodiment in cross section along the line II in Fig. 2.

Fig. 2 is an axial section along the line II-II in Fig. 1;

Fig. 3 shows a second embodiment in cross section along the line III-III in Fig. 4;

Figure 4 is an axial section along the line IV-IV in Fig. 3.

5 shows an interior view of the housing cover, cut along the line VV in FIG. 4, with a representation of the associated axial disk;

6 shows a third embodiment in an axial section analogous to FIG. 4;

Fig. 7 is an interior view of the housing cover, cut along the line VII-VII in Fig. 6, corresponding to Fig. 5;

8 shows a fourth embodiment in an axial section analogous to FIG. 4;

FIG. 9 shows a cross section corresponding to FIG. 5 along the line IX-IX in FIG. 8;

10 shows a fifth embodiment in cross section along the line XX in FIG. 11;

FIG. 11 shows an axial section along the line XI-XI in FIG. 10;

FIG. 12 shows a cross section corresponding to FIG. 5 along the line XII-XII in FIG. 11;

Fig. 13 shows a sixth embodiment in cross section along the line XIII-XIII in Fig. 14;

Fig. 14 is an axial section along the line XIV-XIV in Fig. 13;

FIG. 15 shows a cross section corresponding to FIG. 5 along the line XV-XV in FIG. 14;

16 shows a seventh embodiment in cross section along the line XVI-XVI in FIG. 17;

Fig. 17 is an axial section along the line XVII-XVII in Fig. 16, and

FIG. 18 shows a cross section corresponding to FIG. 5 along the line XVIII-XVIII in FIG. 17.

The internal gear machine shown in FIGS. 1 and 2 comprises a housing designated as a whole by 1, which consists of a cup-shaped housing part 11 and one on the latter Front end of the housing cover 12 is constructed. In the cup-shaped housing part 11 is a pinion shaft 14 rotatably mounted on which a pinion 2 rotatably attached is. The pinion 2 meshes with a ring gear 3, which in one Bearing ring 4 is added and rotatably mounted therein. The Pinion 2 and the ring gear 3 are, as is apparent from Fig. 1, stored relative to each other with an eccentricity e. The Eccentricity e, d. H. the distance between the pinion axis and the ring gear axis, corresponds to the theoretical Gear geometry of pinion and ring gear and sets play-free rolling or sliding of the gears ahead of each other. The teeth of the pinion 2 and Ring gear 3 mesh with each other in such a way that on the left in Fig. 1 in the region of the dividing line A Teeth of the pinion 2 fully into the tooth spaces of the ring gear 3 engage and rest on the tooth flanks while they are on the opposite, right in Fig. 1 from the tooth gaps of the ring gear 3 have emerged. In this non-meshing ring gear region E support several of the Tooth tips of the pinion 2 and the ring gear 3 (in the shown embodiment 3 tooth heads each) one after the other in the course of the rotation. The Number of teeth and the geometry of the meshing Gears are chosen so that this type of combing can be effected. In the embodiment shown the tooth flanks are formed as involute curves, whereby the tooth heads to achieve rolling and sliding contact are rounded for the purpose of sealing. The number of teeth on the Ring gear 3 differs from that of pinion 2 at 1.

When rotating the pinion 2 in the direction of the arrow indicated direction increases the released Tooth gap space, based on the full engagement of the Pinion toothing in the ring gear toothing above the Dividing line A, increasing until reaching that of FIG. 1 visible state when the Dividing line A (on the right side in Fig. 1). Hereby is the suction space S above the dividing line Internal gear machine formed. Under the dividing line the free space between the teeth decreases again, so that the pressure chamber D is formed. 1 are the suction space S and the pressure space D in their projection hinted at; however, it is understood that the suction space S and the pressure chamber D is in the circumferential direction within extend the toothing.

The bearing ring 4 is in a housing bore 15 of the pot-shaped housing part 11 with a radial clearance of about 0.2 mm added. The wall of the housing bore 15 is partially penetrated by a bearing pin 16 which in the Bottom of the housing bore 15 is pressed firmly. With the protruding beyond the wall of the housing bore 15 is largely semi-cylindrical part of the bearing pin 16 this in an axially directed groove 17 of the bearing ring 4 added. The axial groove 17 is the shape of the bearing pin 16 adapted and also partially cylindrical.

The bearing pin 16 engaging in the axial groove 17 forms for the bearing ring 4 one to the axes of pinion 2 and Ring gear 3 parallel pivot axis about which the Bearing ring 4 within the available Radial play in the housing bore 15 is pivotable. How 1, this pivot axis lies in one Quadrant of the bearing ring 4, which is between the non-meshing ring gear area E and the center of the Pressure chamber D extends. In the shown The swivel axis is in one embodiment Angular distance of about 80 ° from the apex of the non-meshing ring gear area E. At this apex are two teeth of pinion and ring gear with their Tooth heads largely aligned with each other.

The mode of operation of the internal gear machine according to FIG. 1 and 2 is the following:

When rotating the pinion 2 in the direction of rotation shown is conveyed medium through a suction channel, not shown the suction space S between the teeth of the pinion 2 and promoted the ring gear 3. From the pressure room D that Pumped medium with increased pressure by a not shown Pressure channel pressed. The related structure of a Internal gear machine is well known and required therefore no separate explanation here.

The pressure forces prevailing in the pressure chamber D between the intermeshing teeth work along one Resulting R so that the ring gear 3 is separated from the pinion 2 seeks to remove, d. H. there is a tendency that the existing contact due to the tooth geometry between the teeth of pinion 2 and ring gear 3, especially the sealing contact between the tooth tips in the non-meshing ring gear area E is lost. The through the bearing pin 16 or its engagement in the Axial groove 17 formed pivot axis of the bearing ring 4 is however closer to the non-meshing ring gear region E than that Line of the resultant R. Since the resultant R over the ring gear 3 acts on the bearing ring 4, thus arises Torque about the pivot axis 16, 17 in Fig. 1 in Counterclockwise. Through this torque the Bearing ring 4 pivoted about the pivot axis 16, 17, whereby the corresponding to the non-meshing ring gear region E. Ring section approximately radially with respect to the pinion axis and is moved towards it. Consequently, in the non-meshing ring gear area E the tooth heads of pinion 2 and ring gear 3 with a size of the resultant R proportional force moves against each other. This is the Sealing contact in this toothing area proportional to pressure maintained.

The bearing ring 4 has at a point that the Apex of the non-meshing ring gear region E is assigned a further axial groove 18 with a Rectangular cross section on its outer circumference. This Axial groove 18 is in the bottom of the housing bore 15 Receiving hole 19 associated with a hairpin spring 20 is held. The hairpin spring 20 protrudes into the axial groove 18 and loads the bearing ring 4 radially so that the teeth of the ring gear 3 in the non-meshing ring gear region E. their tooth heads are pressed against each other. This Load direction largely corresponds to that Direction of movement that the bearing ring 4 as a result of Performs pivoting movement about the pivot axis 16, 17. The The force of the hairpin spring 20 can be kept relatively low as it only serves the necessary Sealing contact between the tooth heads in the non-invasive Ring gear area E during the startup process To ensure internal gear machine, d. H. at a time, in which no operating pressure has yet been built up in pressure chamber D. and therefore no compressive forces act.

The position and direction of the resultant R is largely predeterminable and corresponds essentially to that in Fig. 1 shown. The pressure build-up in the pressure chamber D leaves in a known manner through pre-filling slots on the teeth of pinion 2 and / or ring gear 3, so that z. B. a largely over the tooth gaps of the pressure chamber D. same pressure exists. In this case the Resulting R drawn perpendicular to that in Fig. 1 line shown which is the vertex of the non-meshing ring gear region E with the pinion tooth fully engages in a tooth gap of the ring gear.

In contrast to the one described above Embodiment according to FIGS. 1, 2 show FIGS. 3 to 18 embodiments of the invention Internal gear machine on the front of the gearing have sealing axial discs. The Interaction of pinion and ring gear, their inclusion in a bearing ring and its mobility relative to the However, the housing bore corresponds to that of the Embodiment according to FIGS. 1, 2 and needs therefore no separate explanation.

3 to 5 is the Pinion shaft 114 both in the cup-shaped housing 111 and also in the housing cover 112 via bushings 113 stored. The bearing ring 104 has on its inner circumference one pressed in and consequently one with the bearing ring Unit-forming race 105 made of a bearing metal, e.g. B. Bronze, in which the ring gear 103 is mounted. How from Fig. 4 shows, the bearing ring 104, 105 exceeds the Width of pinion 102 and ring gear 103 significantly and is with its end faces slidable on the walls of the Housing 111 or cover 112. On the other hand, is due to the Teeth of pinion and ring gear on both sides of the front Sides each an axial washer 130, the shape of which Fig. 5 emerges. Each of the two axial washers has a pressure field 107 on its surface facing the toothing on. In the area of the pressure field 107, the axial disk 130 arranged on the side of the housing cover 112 is, three openings 108, which from the pressure chamber to the Pressure outlet channel, not shown, in the housing cover 112 to lead. The housing cover 112 faces diametrically opposite Pressure outlet channel on a suction inlet channel 109, which is expanded at its mouth to a suction field 110. In the wall of the housing 111 and the housing cover 112 is each a pressure field 131 indicated by which the respective Axial disk 130 from the outside against the action of inner pressure field 107 is applied so that the Axial disc with all operating conditions sealing contact with Retains pinion 102 and ring gear 103. Training and Effect of the pressure fields on axial washers well-known and therefore need at this point no further explanation.

On the surface facing the toothing, the Axial disks 130 prefill slots 132 through which the Pressure distribution in the pressure chamber of the gearing is controlled. Each thrust washer 130 supports itself for the purpose of it Secure position on the one hand over the circumference of a bearing bore 133 on the associated bearing bush 113 and on the other on one in the housing 111 or the housing cover 112 inserted pin 134 from. The pins 134 each protrude into a blind hole in the outer face of the Axial disks 130 and are thereby held axially.

The embodiment according to FIGS. 6 and 7 differs differs from that according to FIGS. 3 to 5 only in that the axial washers 230 align with the inner circumference of their Bearing bore 233 not on the respectively assigned Support bushing 213, but directly on the Pinion shaft 214. The bearing bushes 213 thus end in front of the Axial washers 230.

In the embodiment according to FIGS. 8 and 9, the Axial disks 330 approximate a sickle shape and embrace the associated bushings 313 without relying on it to support. In this case, to secure their position each thrust washer 330 provided two pins 334, 335 which in each case in the end regions of the axial disks 330 Blind hole on the one hand and in a corresponding hole of the housing on the other hand. The bearing bushes 313 extend in this embodiment among the Axial disks 330 close to the toothing.

In the exemplary embodiments described above 3 to 9, the axial disks are relative to the housing fixed. It follows that in operation the internal gear machine with the operational movement of pinion, ring gear and bearing ring relative to the housing due to the permitted pivoting movement of the bearing ring the pressure space in the toothing relative to that in the Axial disks provided control slots and pressure fields also changed its location. Because this inevitably Deviations from the optimal position set occur, the efficiency can be reduced. Around to prevent this; are in accordance with the embodiments 10 to 18, the thrust washers in a manner arranged that they together with pinion, ring gear and Bearing ring are movable together. Are in all Cases the thrust washers as part of the game, e.g. B. of Bearing play, sufficiently free with respect to the pinion shaft, that they can follow the pivoting movement of the bearing ring, in order not to achieve the desired sealing contact of the tooth heads hinder.

In the embodiment according to FIGS. 10 to 12, the Bearing ring 404 on the right (in FIG. 11) on both End faces a radial groove 440 on the groove bottom with the End faces, the toothing lies in one plane. The Axial disks 430 have one on their outer edge Extension 441, which projects into the groove 440 with play and is performed in it. With the inner circumference of your bearing bore 433, the thrust washers 430 support themselves with a certain amount Bearing play on the circumference of the pinion shaft 413. By this support on the one hand and the guidance of the extension 441 in groove 440, on the other hand, is each thrust washer 430 with the movement unit pinion / ring gear / bearing ring coupled and therefore carries out their movements.

Furthermore, the respective pressure field 407 are the External pressure fields 431 assigned to axial disks 430 exclusively on the respective outer surface of the Axial disks 430 formed. With the operational Pivotal movements of the bearing ring 404 around the bearing pin 416 therefore remains the location of the pressure fields 407, 431 and the Control slots 432 largely relative to the pressure chamber unchanged. The raceway pressed into the bearing ring 404 405 is limited to the width of the ring gear.

The embodiment according to FIGS. 13 to 15 differs differs from the embodiment described above 10 to 12 by the shape of the axial discs 530 and their type of position assurance. The thrust washers 530 are in in this case with a circular border and between the pinion, Ring gear on the one hand and the associated housing wall on the other hand, fully absorbed in the space created by the Larger width of the bearing ring compared to the ring gear and pinion 504 is created. Again, the width of the in the Bearing ring 504 pressed race 505 to the width of the Ring gear limited. The outer circumference of the axial washers 530 lies on the exposed inner circumference of the bearing ring 504 close and has a small extension 541 with which the axial disc 530 in the on each end face of the Bearing rings 504 engages provided radial groove 540. Since the Thrust washers 530 over their outer circumference in the bearing ring 504 are held, encompasses the circumference of their bearing bore 533 with the pinion shaft 513 in this embodiment clear game.

Because the thrust washers 530 in this embodiment are pinions and completely cover the ring gear on the face is in the range of Suction space of the teeth a part-circular breakthrough 536 provided that the inflow of the medium from the Suction channel 509 allowed for toothing.

Also in the embodiment according to FIGS. 16 to 18 the axial washers 630 are circular, but have such a shape large outer diameter that they are beyond the ring gear overlap the bearing ring 604 on its end faces. For this is the width of the bearing ring 604 along with that in it Pressed race 605 to the width of the ring gear and Pinion limited. To turn the axial washers 630 part of the movement unit pinion / ring gear / bearing ring make, the bearing ring 604 has an axially continuous Hole in which a pin 642 is received. This protrudes on both ends of the end faces of the bearing ring 604 out and into elongated holes 643 of the axial washers 630. The are supported with the inner circumference of their bearing bore 633 Axial washers 630 in this case with a tight bearing clearance pinion shaft 613. Through this and through the pin 642 they are uniform in motion with the bearing ring 604 coupled. As described in the above Embodiments according to FIGS. 10 to 15 therefore remain the relative position of the control slots 632 and the pressure fields 607 or 631 received for the teeth. Here too, the Axial washers 630 made a breakthrough in the area of the suction chamber 636 to ensure access to the pumped medium.

The invention is not based on the training of Internal gear machine according to those described above Embodiments limited. So it is basically possible instead of the one selected for pinion and ring gear Involute toothing with rounded tooth heads one Trochoid or cycloid toothing to choose. Farther can also be a mirror image of the on the bearing ring Dividing line A one of the axial groove for the swivel axis appropriate axial groove may be provided in the event that the internal gear machine for both directions of rotation of the Pinion 2 should be designed. In this case the would Bearing pin determining the pivot axis is offset accordingly be arranged in the housing. Finally, the grooves must be in the end faces of the bearing ring (Fig. 10,13) is not radial enforce its peripheral surface, which is only for simplification the production is preferred, but can on the Internal circumference should be limited recesses. It can also Location of projection and recess to achieve the desired positive locking between the axial washer and Bearing ring may also be interchanged.

Although there are always two in the above exemplary embodiments Axial disks are shown and described basically only one axial disk can be provided, where necessary control slots and Pressure fields are provided directly in the housing wall, rest on the front of the pinion and ring gear. Finally can be shown and described throughout as a pen Swivel axis of the bearing ring also through a ball be realized in a dome-shaped recess the housing bore is received. This is the Bearing ring not only around a parallel to the pinion axis Swivel axis, but swiveling on all sides to Adaptation movements to shape deviations of the individual To be able to execute components.

Claims (19)

1. Unlined internal gear pump having a housing (1), a bearing ring (4) which is non-rotatably accommodated in a bore (15) in the housing and which can be pivoted about a pivot axis parallel to its axis, an internally toothed hollow gear (3) mounted so as to revolve in the bearing ring, and a pinion (2) which is rotatably mounted in the housing, meshes with the hollow gear and whose teeth, as a result of full engagement in tooth gaps in the hollow gear, on the one hand, and sealing contact with the tooth tips of the hollow gear in a non-engaging region (E) of the hollow gear that is approximately diametrically opposite the tooth-gap engagement, on the other hand, define a suction space (S) and a pressure space (D) in the toothing, characterized in that in order to maintain a substantially equal pressure over the entire pressure space (D), sealing contact between the teeth of pinion and hollow gear is restricted to the region of the full tooth engagement and of the non-engaging region (E) of the hollow gear, and in the pressure space, on a wall of the housing (11, 12) that rests on the side faces of the teeth of the pinion and/or hollow gear, or on an axial disc (130, 230, 330, 430, 530, 630), at least one control slot (132, 432, 632) is provided, and in that the pivot axis (16, 17; 416) of the bearing ring is arranged with respect to the resultant (R) of the hydraulic pressure prevailing in the pressure space (D) such that a torque generated by the resultant effects pivoting of the bearing ring with the effect of mutual approach of the tooth tips of pinion and hollow gear in the non-engaging region (E) of the hollow gear.
2. Internal gear pump according to Claim 1, characterized in that the pivot axis (16, 17) is located on the side of the pressure space (D) between the line of the resultant (R) of the pressure forces and the annular section of the bearing ring associated with the non-engaging region (E) of the hollow gear.
3. Internal gear pump according to Claim 2, characterized in that the pivot axis is located closer to the line of the resultant (R) than to the annular section associated with the non-engaging region (E) of the hollow gear.
4. Internal gear pump according to one of Claims 1 to 3, characterized in that the pivot axis is arranged on the outer circumference of the bearing ring.
5. Internal gear pump according to Claim 1, characterized in that the pivot axis is formed by a bearing pin (16) which is fixed to the housing and which is accommodated with its circumferential face partially in an axial groove (17) in the outer circumferential face of the bearing ring.
6. Internal gear pump according to one of Claims 1 to 5, characterized in that the annular section associated with the non-engaging region (E) of the hollow gear is spring-loaded radially towards the pinion shaft.
7. Internal gear pump according to Claim 6, characterized in that the annular section associated with the non-engaging region (E) of the hollow gear has, on the outer circumference, a recess (18) in which a spring (20) supported on the housing (1) engages.
8. Internal gear pump according to one of Claims 1 to 7, characterized in that the pressure space (D) is sealed off by axial discs (130 to 630) resting on the side faces of the toothing of pinion and hollow gear.
9. Internal gear pump according to Claim 8, characterized in that each axial disc (130, 230) is supported by at least one protrusion (pin 134) on the housing and by a bearing bore (133, 233) on the pinion shaft (113, 114; 214).
10. Internal gear pump according to Claim 8, characterized in that each axial disc (330) is supported by at least two protrusions (pins 334, 335) on the housing.
11. Internal gear pump according to Claim 8, characterized in that the axial discs (430, 530, 630), together with the bearing ring (404, 504, 604) and the hollow gear, can be pivoted relative to the housing.
12. Internal gear pump according to Claim 11, characterized in that the bearing ring is connected to the axial discs by a form fit.
13. Internal gear pump according to Claim 12, characterized in that the bearing ring (404, 504) has at least one recess (440, 540), in which a protrusion (441, 541) formed on each axial disc (430, 530) engages.
14. Internal gear pump according to Claim 13, characterized in that each protrusion on the axial discs is associated with a separate recess in the bearing ring.
15. Internal gear pump according to Claim 13 or 14, characterized in that the protrusion is guided with play in the recess in the bearing ring, and the axial disc is supported with a bearing bore (433, 533) on the pinion shaft.
16. Internal gear pump according to Claim 11 or 12, characterized in that each axial disc (530) is circular and is accommodated with its outer circumference in the bearing ring (504).
17. Internal gear pump according to Claim 11, characterized in that each axial disc (630) is circular and is supported on the associated end face of the bearing ring (604) and with a bearing bore (633) on the pinion shaft.
18. Internal gear pump according to Claim 17, characterized in that the axial disc is connected to the bearing ring by a form fit.
19. Internal gear pump according to Claim 18, characterized in that the form-fitting connection comprises a pin (642) which engages in a bore in the bearing ring and in a slot (643) in the axial disc.

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