EP0846861B1 - Continuously variable annular gear pump - Google Patents

Abstract

The pump has a stationary housing (1) and an annular ring set (5) with inner rotor (3) and meshing outer rotor (4). The gear ration of the inner rotor and the annular ring set is equal to 1. The bearing (12) of the outer rotor along its outer diameter (13) is inside the adjusting ring (14) of preferably the same width. The adjusting ring moves slip-free with its outer part circle (15) on an inner part circle (16). The difference between the diameters of the two part circles is double the eccentricity (17) of the ring set.

Description

The invention relates to an adjustable gerotor pump according to the preamble of Claim 1, in its specific delivery rate [delivery volume / speed] can be changed.

Known gear pumps have a system-specific constant specific delivery rate because the geometry of the displacement cells cannot be changed. The expanding and the compressing delivery cells fluctuate during the Rotation of the gear set from a minimum to a maximum and again back to the minimum because the teeth are rigid and cannot be changed. From this The constancy of the specific delivery rate automatically results in a proportionality the delivery rate of the pump over the speed as long as the filling level of the delivery cells Is 100%.

In many applications, however, this proportionality is disruptive and undesirable. For a press, for example, there is a high delivery quantity for rapid traverse of pressure oil is necessary, but in the final phase of the working stroke only high pressure is still required, but the demand for oil output drops to zero back. Since the drive speed of such pumps usually remains constant, creates a high pressure oil flow surplus, which is energy loss flows back into the oil tank.

This excess oil flow is particularly disruptive, for example, in engine lubrication pumps, in motor vehicles and in automatic oil supply pumps Transmissions. These require at low motor and therefore low pump speed a minimum delivery rate required when idling and at high speed a minimum oil pressure, but the oil quantity requirement is at higher speed far below the proportionality line, at maximum speeds mostly below a third of the proportionality.

Aside from many efforts to solve this problem by suction throttling, solutions with adjustable vane pumps have been proposed. solutions with two-register pumps to achieve at least two delivery stages or with two variably working sets have also become known.

A good solution is a gerotor pump as an internal gear pump, which none Crescent moon needed because the tooth shape is chosen so that by tooth head contact each tooth chamber is reliably sealed by the neighboring tooth chambers is, so that a good volumetric efficiency is achieved. With such Gerotor pumps have the possibility that the center distance of the inner rotor to the external rotor or the angular position of the eccentric axis, in relation to the housing and thus be changed in relation to the inlet and outlet openings in the housing can.

A constructive solution could be that the external rotor in one Eccentric ring is mounted, which is rotatably arranged and adjustable in the housing. For a delivery rate adjustment up to An angle adjustment is close to zero, which is very desirable when starting cold the eccentric axis of 90 ° is required. This means that the Eccentric ring for adjusting the eccentricity axis of the barrel set by 90 ° and must therefore be rotated over large circumferential paths. The control spring would also have to do this drive very long distances, which is because of the required soft characteristic would lead to dimensions that are difficult to achieve. Because especially at Motor vehicle engines and automatic transmissions very frequent and fast speed changes would take place, the eccentric ring high spin and Delays experience what leads to large adjustment forces, to large adjustment resistances and would lead to high wear. That too is Large control rooms are at great risk of contamination.

A generic gerotor pump emerges from DE 42 31 690 A1.

The invention solves the problem of small control paths and quick, precise reaction the control of variable gerotor pumps through the characteristic features of Claim 1.

According to the laws of internal gears, the negative ratio of the angle of rotation the eccentric axis or the planet carrier to the angle of rotation of the pinion or Planet gear equal to the number of teeth of the pinion if the number of teeth difference between ring gear and pinion is one. Since according to claim 1, the circumference or the pitch circle of the external toothing on the adjusting ring is proportional is large, e.g. has 16 teeth, is the negative angle adjustment the eccentric axis 16 times the angle of rotation of the adjusting ring around its own Axis. Accordingly, the adjustment ring performs small angular rotations and thus small adjustment paths because it only has a small rolling movement in the housing performs.

The only requirement to be met here is that the diameter difference of circles rolling inside one another equal to twice the eccentricity of the Gear set is so that the center distance of the gears during the whole Control path remains exactly constant. Furthermore, the circles roll together without slipping from.

In order to ensure this slip-free rolling, according to the invention, a Execution proposed according to claim 2.

Because of the small adjustment movement of the adjustment ring, there is now also the Possibility of realizing a reversing pump with reasonable construction costs can be according to subclaim 6, a requirement for the construction of hydrostatic Drives and controls that always also reverse the direction of rotation desire.

The toothing of an adjustment gear designed as an internal gear is preferred a trochoid or a between the adjusting ring and the housing Cycloid internal gear.

In the eccentric angle range with a greatly reduced swallowing quantity of the pump arises in the area where the teeth of the ring gear set of the pump cross the webs Kidney-shaped housing openings forming low and high pressure openings paint over the danger of cavitation on the suction side and that of the Pinch oil on the pressure side. To the associated unwanted side effects to reduce, has the adjusting ring seen in the axial direction the opposite side to the kidney-shaped low-pressure and high-pressure openings circumferential, through the housing wall closed connection groove that together with built-in connecting grooves in the area the webs connecting expanding and compressing conveyor cells. A channel connection is proposed between these working chambers allows a compensation oil flow, so that excessive pressure peaks at the pinch oil point and extreme negative pressures at the cavitation point can be avoided.

Especially for pumps that have very low-viscosity liquids, such as motor oil when hot, should promote good sealing of all work, Control and pressure compensation rooms indispensable. For example, as claimed 5 discloses the space between the inner circumferential circle of the housing and the serve outer circumferential circle of the adjusting ring as a control piston, it is advantageous to take special precautions according to claim 7 and / or 8.

The execution of a zero stroke pump according to claim 9 reduces the construction effort, because after that only the compression chamber in the gerotor pump itself has the high pressure leads. However, since the momentary pole is when the delivery rate is reduced, that is the pitch point around which the adjusting ring rotates in each rotational position changes in such a way that in the closed position of the adjusting ring hydrostatic force component of the compacting workspace no longer a moment exerts on the adjusting ring, the pump is not quite when using a spring adjust to zero. In this case, the high-pressure working area also points the largest cross-sectional area in the axial direction, which may to inadmissibly large axial deflection of the housing and in particular the Lid leads. Therefore, sealing measures are preferred according to the Claims 7 and / or 8 made. These features of the invention Gerotor pumps are, under certain circumstances, even with known means, all the more so more advantageous than the housing in engine construction for cost reasons, mostly in light metal die casting, the barrel and the adjusting ring by means of sintering and the Lids are often designed as sheet metal parts. Furthermore, the processing effort be kept to a minimum on the housing, which largely depends on turning and drilling as well on milling operations with driven tools on NC lathes should limit.

The external toothing of the adjustment gear is preferably made in one piece with the Adjustment ring, especially by sintering. The external teeth can basically also formed by a stamped sheet metal ring on the adjusting ring become. The internal toothing can advantageously be punched on the housing Sheet metal ring are formed. In another embodiment, the internal toothing of the adjustment gearbox made in one piece with the housing, which then is preferably also sintered together with the internal toothing. The The inner rotor of the pump can be shrunk onto the shaft, preferably Axial connecting channels are provided between the shaft shrink fit and the inner rotor are. In an alternative embodiment, the inner rotor is integral with the Shaft executed.

If the gerotor pump according to the invention is to be used as a high pressure pump, then high demands on the construction must be met. Particularly advantageous is the teeth of the ring gear set to avoid rapid wear to train on one of the two runners as roles. This also works with slow-running high-pressure rotary piston machines.

The rollers are so that the machine does not become too large in diameter preferably arranged on the inner rotor.

This creates particularly robust conditions and small, compact dimensions then when the inner rotor as a bearing for the rollers integrally with the shaft is performed.

When operating such gerotor pumps, the large surfaces on which the High pressure, considerable deformation forces, especially on the adjusting ring. Because this is also the radial slide bearing for the highly loaded external rotor must form, the hydrostatic force acting from the inside out compensated from the outside to the inside as much as possible. This can be done achieved that the adjusting ring and thus the teeth of the adjusting gear extend over the entire width of the pump runner and the teeth of the adjusting mechanism forms pressure-tight chambers, which depend on the working pressure or can be partially pressurized by a high pressure. This will on Adjustment ring radially balanced the forces, so that the deformations at least can be greatly reduced.

The radial compensating force can then also be used to adjust the delivery rate Toothed ring pump can advantageously be used if the chambers in the Interlocking of the adjustment gear via channels and preferably a control rotary valve within limits both in their number and in their rotational position can be changed, as is also slow with the above mentioned running high-pressure rotary piston machines can be used. The The control rotary valve can be adjusted in angle to adjust the position of the high and low pressure chambers. That to adjust the Adjustment ring necessary adjustment torque arises from the fact that the resulting Force vector of the partial pressure field in the under pressure, preferably under High pressure, standing chambers of the toothing of the adjustment gear on the side The momentary pole M points past as the fulcrum, so that by rotating the pressure field at the same time a lever arm is created. The adjustment ring will then go in so far turn the toothing of the adjustment gear until the torque is balanced between the adjustment moment and the moment that relates to the working pressure field of the new instantaneous pole M in the opposite direction of rotation.

It is particularly in the case of a gerotor pump for a closed circuit advantageous on the opposite end of the shaft of the drive shaft Pump to provide a flushing and control pump, which in a known manner via check valves in the low pressure area with greatly reduced pressure the external one Leakage oil replaced.

Throttles are preferably provided in the channels to the control rotary valve, and the control rotary valve has control bores around the chambers in the leakage spaces to connect to the tank.

This type of pressure compensation and adjustment of the controllable according to the invention Gerotor pump requires a precise manufacturing of the toothing of the adjustment gear, thus the leakage losses from the compensation and control field in the Intake area or in the leak spaces, the so-called external leakage losses Gerotor pump, remain within permissible limits. This is with a variable displacement pump all the more important, because with the pump regulated at the same pressure, the percentage Leakage share of the effective delivery rate increases anyway, so that the volumetric Efficiency drops sharply.

However, the adjustment of the adjustment ring is not directly hydraulic as above described, but made mechanically according to claim 6, then serve the high-pressure cells between the teeth of the adjustment gear only the force and thus the tension compensation in the adjusting ring to minimize its deformation. In this case, the number and choice of the high pressure cells are selected so that the adjusting ring due to the internal working pressure field, the tooth heads of the toothing of the Adjusting gear keeps in touch contact. In this case, both parts, the Adjustment ring with its external teeth and the housing ring with its internal teeth, are produced with sufficient accuracy using the sintering process. It can namely enough tooth play will then be provided to bridge the manufacturing tolerances.

An extremely compact design is essential for a high-pressure pump. The rooms subject to pressure must not have large effective areas subject to pressure exhibit. Therefore, in the case of a zero stroke pump, a version with the Feature of claim 15 preferred. Here too there is the problem that the The delivery rate cannot be completely reduced to zero if only the pressure chamber the internal gear pump is used as an adjustment force in the direction of zero stroke, since in this position there is no adjustment torque with regard to the momentary pole of the adjustment ring more is available. The remedy is that with increasing rotation of the adjustment ring these suitable channels or at least such a channel that releases the high pressure in such cells of the auxiliary toothing between the adjusting ring and the housing part, which conducts favor the twisting of the adjusting ring in the direction of the zero stroke.

With a sintering process between the adjusting ring and the housing part is dependent, as already mentioned, that a optimal sealing takes place by contacting the tooth head in the toothing. This is not only due to the working pressure field with undercompensation, but also caused by the radial component of the tooth force at the momentary pole M. It is therefore advantageous if you have a tooth shape for the teeth of the adjusting gear selects a large pressure angle at the point of deepest meshing having. This condition is with a trochoid toothing with circular or hypocycloid-shaped teeth in the ring gear.

The axial play of the adjusting ring in the housing is advantageously essential executed smaller than the axial play of the ring gear set.

Figur 1a

ein erstes Ausführungsbeispiel einer Reversierpumpe in einer ersten Endstellung maximalen Fördervolumens,

Figur 1b

die Reversierpumpe der Figur 1a in ihrer Nullstellung,

Figur 1c

die Reversierpumpe der Figuren 1a und 1b in einer zweiten Endstellung maximalen Fördervolumens,

Figur 2

einen Längsschnitt der Pumpe nach den Figuren 1a-1c,

Figur 3a

ein erstes Ausführungsbeispiel einer Nullhubpumpe in ihrer Endstellung für maximales Fördervolumen,

Figur 3b

die Nullhubpumpe der Figur 3a in ihrer Nullstellung,

Figur 4a

ein zweites Ausführungsbeispiel für eine Nullhubpumpe in ihrer Endstellung für maximales Fördervolumen,

Figur 4b

die Nullhubpumpe der Figur 4a in ihrer Nullstellung,

Figur 5

einen Längsschnitt durch die Pumpe der Figur 4a,

Figur 6a

ein weiteres Ausführungsbeispiel einer Regelpumpe, insbesondere für Hochdruck Anwendungen,

Figur 6b

einen Längsschnitt der Pumpe nach Figur 6a,

Figur 7a

einen Querschnitt der Pumpe nach den Figuren 6a und 6b,

Figur 7b

eine Ansicht der Pumpe nach den Figuren 6a bis 7a mit teilweisem Schnitt,

Figur 8a

die Regelpumpe nach Fig. 6a in einer ersten Endstellung maximalen Fördervolumens mit positiver Förderrichtung,

Figur 8b

die Pumpe nach Figur 8a in ihrer Nullstellung,

Figur 8c

die Pumpe nach den Figuren 8a und 8b in ihrer zweiten Endstellung für maximales Fördervolumen mit negativer Förderrichtung,

Figur 9a

ein weiteres Ausführungsbeispiel einer Nullhubpumpe,

Figur 9b

die Pumpe nach Figur 9a in ihrer Nullstellung und

Figur 9c

einen Längsschnitt der Pumpe nach Figur 9a und 9b,

Figur 10

eine Variante des Ausführungsbeispiels nach Fig. 9a,

Figur 11

den Schnitt A-A nach Figur 10,

Figur 12

den Schnitt B-B nach Figur 10,

Figur 13

die Ansicht X nach Figur 11.

Preferred embodiments of the invention are explained below with reference to drawings. Show it:

Figure 1a

a first embodiment of a reversing pump in a first end position of maximum delivery volume,

Figure 1b

the reversing pump of Figure 1a in its zero position,

Figure 1c

the reversing pump of Figures 1a and 1b in a second end position of maximum delivery volume,

Figure 2

2 shows a longitudinal section of the pump according to FIGS. 1a-1c,

Figure 3a

a first embodiment of a zero stroke pump in its end position for maximum delivery volume,

Figure 3b

the zero stroke pump of FIG. 3a in its zero position,

Figure 4a

a second embodiment for a zero stroke pump in its end position for maximum delivery volume,

Figure 4b

the zero stroke pump of FIG. 4a in its zero position,

Figure 5

3 shows a longitudinal section through the pump of FIG. 4a,

Figure 6a

another embodiment of a control pump, especially for high pressure applications,

Figure 6b

6 shows a longitudinal section of the pump according to FIG. 6a,

Figure 7a

6 shows a cross section of the pump according to FIGS. 6a and 6b,

Figure 7b

6 shows a view of the pump according to FIGS. 6a to 7a with a partial section,

Figure 8a

6a in a first end position of maximum delivery volume with positive delivery direction,

Figure 8b

the pump according to Figure 8a in its zero position,

Figure 8c

8a and 8b in their second end position for maximum delivery volume with negative delivery direction,

Figure 9a

another embodiment of a zero stroke pump,

Figure 9b

the pump according to Figure 9a in its zero position and

Figure 9c

9 shows a longitudinal section of the pump according to FIGS. 9a and 9b,

Figure 10

a variant of the embodiment of FIG. 9a,

Figure 11

the section AA according to FIG. 10,

Figure 12

the section BB of Figure 10,

Figure 13

the view X according to FIG. 11.

A gerotor pump shown in FIGS. 1 a to 2 has an inner rotor 3 and an external rotor 4, one with their external and internal teeth Form gear ring 5. The external toothing of the inner rotor 3 has one Tooth less than the internal toothing of the external rotor 4.

The inner rotor 3 is shrunk onto a rotationally driven shaft 2. Between the shaft shrink fit and the inner rotor 3 are axial connecting channels 48 intended.

Both the shaft 2 and thus the inner rotor 3 and the outer rotor 4 are in a pump housing, parts of which are designated 1, 1 'and 1 ", rotatable stored. The axis of rotation of the external rotor 4 is spaced parallel, i.e. eccentric, to the axis of rotation of the inner rotor 3. The eccentricity or the distance between these two axes of rotation is designated 17.

The inner rotor 3 and the outer rotor 4 form a fluid delivery space between them. This fluid delivery chamber is sealed off from one another in a pressure-tight manner Conveyor cells 7 divided. The individual conveyor cells 7 are each between two successive teeth of the inner rotor 3 and the internal teeth of the External rotor 4 formed by two successive teeth of the inner rotor Head or flank contact 6 with two successive, opposite Have teeth of the inner toothing of the outer rotor 4.

Kidney-shaped adjoining the conveyor cells 7 are located in the housing Except grooves 8 and 9, which a fluid inflow and outflow to and form from the conveyor cells 7. In the position of the external rotor shown in FIG. 1a 4, the groove 8 forms the low-pressure opening for supplying the fluid and Groove 9 the high pressure opening for the fluid drain. The groove 8 extends from near a location of deepest tooth engagement in the area of a web 11 on the housing side almost semicircular up to close to a place of slight tooth meshing, that of a further housing-side web 10 diametrically opposite the web 11 is covered. The groove 9 on the high pressure side in Figure 1a extends in Housing mirror-symmetrical to groove 8 on the opposite side of the both webs 10 and 11. From the deepest tooth mesh at web 11 to the location The smallest tooth mesh at the web 10, the conveyor cells 7 in the direction of rotation D increasingly larger, then from the smallest tooth mesh to Remove the deepest tooth mesh. When rotating the inner rotor 3 is thus through the expanding conveyor cells 7 in the area of the low pressure opening 8 Fluid sucked in, transported over the place of minimal tooth mesh and removed through the high pressure opening 9 under higher pressure. In the in Figure 1a shown position is the axis of rotation of the external rotor 4 on the site deepest meshing over the axis of rotation of the inner rotor 3 to the lowest location Straight line drawn into the tooth mesh, namely towards the location of the smallest tooth mesh offset from the axis of rotation of the inner rotor 3. In this situation of eccentricity 17 and direction of rotation D becomes the maximum delivery rate or maximum Delivery volume from the low pressure side 8 to the high pressure side 9 reached.

In order to be able to change the delivery rate "V ˙", the external rotor 4 is in a ring 14 added, which in turn can be adjusted relative to the housing. In This adjustment ring 14 is the outer rotor 4 by means of its outer circumference 13 a sliding pivot bearing 12 is freely rotatable. The adjusting ring 14 has one External toothing 24 which meshes with an internal toothing 24 '. The internal toothing 24 'is non-rotatably connected to the housing. Your center falls with the Rotation axis of the inner rotor 3 together. The internal toothing is in the exemplary embodiment 24 'formed on a stamped sheet metal ring 27 on the housing part 1 "or rigidly attached to the housing part 1 (FIG. 2). The internal toothing 24 ' could, however, also be formed directly in one piece on the housing.

The housing with the internal toothing 24 'and the adjusting ring 14 with the external toothing 24 form an adjustment gear 20 for adjusting the angular position of the External rotor 4 to inner rotor 3. For this purpose, the internal toothing 24 'has at least one tooth more than the external teeth 24 of the adjusting ring 14. Im In the exemplary embodiment, the tooth difference is exactly one. Furthermore, the Difference in the diameter of the root circle of the internal toothing 24 'and the tip circle the external teeth 24 double the eccentricity 17.

By comparing the adjusting ring 14 in the direction of rotation D of the inner rotor 3 small angle γ with constant mutual engagement of the two Gears 24 and 24 'of the adjustment gear 20 is rotated so that the tip circle 15 of the adjusting ring 14 and the root circle 16 of the internal toothing 24 'slip-free roll against each other, the axis of rotation of the external rotor 4 moves out of position of Figure 1a against the direction of rotation of the inner rotor 3 by 90 ° The axis of rotation of the inner rotor 3 is initially in the position shown in FIG. 1b. The The position shown in FIG. 1b is the zero position of the pump, in the ideal case no fluid is pumped. In the zero position, the slot openings 8 extend and 9 symmetrically on both sides of the deepest and least meshing locations.

In Figure 1c, the pump of Figures 1a and 1b is in its second end position shown. In this position the fluid is then used as a low pressure opening Acting groove opening 9 for the groove opening correspondingly acting as a high pressure opening 8 funded. For this purpose, the adjustment ring 14 was around the Angle γ rotated clockwise.

The pump of the embodiment according to Figures 1a to 2 is by mechanical Actuating means adjusted. For this purpose, a two-armed rocker arm 41, 43 is around an axis 42 spaced parallel from the axis of rotation of the inner rotor 3 between two end positions, namely those of Figures 1a and 1c, pivotable back and forth. The pivoting movement of the rocker arm 41, 43 is achieved by means not shown motorized. The storage of the rocker arm 41, 43 takes place in the between the two side housing parts 1 'and 1 "clamped middle housing part 1. The axis of rotation 42 of the rocker arm 41, 43 lies in the zero position of FIG. 1b seen in the same plane as the axis of rotation of the external rotor 3 and the Axis of rotation of the inner rotor 4. The front, from the rocker arm axis of rotation 42 to the both mentioned axes of rotation rocker arm 41 is on its front End rotatable about an axis 44 parallel to the rocker arm axis 42, which is in the zero position 1b also lies in the plane already mentioned, with the Adjustment ring 14 coupled. The front arm 41 is out of this zero position of the rocker arm can be swiveled to both sides.

The aforementioned angle γ is the angle around which the adjusting ring 14 is turned its own axis rotates when the rocker arm 41 is actuated.

In Figure 2, the pump is shown in section A-A of Figure 1b. The rotary drive Shaft 2 is in the two housing halves 1 'and 1 "in the longitudinal direction the shaft 2 are arranged side by side and between them Include rotating parts of the gerotor pump, rotatably slide bearings and by means of sealed with a seal to the outside. The fluid supply and discharge are in the housing part 1 '' provided; the two slot openings 8 and 9 in both housing halves 1 ' and 1 ". The adjusting ring 14 is only at one axial end with the external toothing 24 provided. The sheet metal ring 27 in turn is on a circular ring cylinder 1 attached, which surrounds the adjusting ring 14 and an intermediate housing between the two housing halves 1 'and 1 ". The inner peripheral surface of the Intermediate housing 1 and the outer peripheral surface of the adjusting ring 14 form in their non-toothed areas rolling cylinder surfaces 26 and 29 over which the Adjustment ring 14 due to the adjustment gear 20 slip-free compared to the circular cylindrical Intermediate housing 1 rolls. The pitch circles 15, 16 of the adjustment gear are in the rolling cylinder surfaces 26 and 29.

The adjusting ring 14 has seen in the axial direction on the opposite side to the kidney-shaped low pressure and high pressure openings 8, 9 a whole or semicircular all-round connecting groove closed by the housing wall 1 ' 45 which, together with connecting grooves 46 and 47 (FIG. 5) that expand and compress in the area of the webs 10, 11 Conveying cells 7 connects.

Figures 3a and 3b show a zero stroke pump, which is between a regulated Position, the zero position, and a single end position for maximum delivery rate is adjustable. In addition, measures have been taken to use the delivery rate V ˙ limit increasing speed of the inner rotor 3. That from adjusting ring 14 and External rotor 4 formed component is against the force of a pressure spring trained control spring 36 adjusted, namely by the high pressure work space 35 of the pump used as a cylinder space above the external rotor 4 as a control piston becomes.

The control spring 36 is between a first, torsionally rigid linkage on the outside Scope of the adjusting ring 14 and a second linkage designed as a pivot bearing biased to pressure on the housing such that they always the adjusting ring 14 tries to push it into its end position for maximum promotion. To the outrunner 4 or to use the adjusting ring 14 as a control piston, the High-pressure working chamber of the pump, which also functions as a cylinder working chamber 35 to be used, lie over the inner peripheral surface of the outer rotor 4 in such a way that the adjusting ring 14 against the force of the control spring 36 in the adjusting mechanism 20 is twisted. The pump regulates itself with increasing speed and thus accompanying increasing pressure on the pressure side automatically to ideally in the zero position shown in Figure 3b.

The use of the pump work space 35 as a cylinder space for the adjustment of the Adjusting gear 20 reduces the construction work of the pump.

The high-pressure working space 35 is also between at least one space 86 the adjusting ring 14 and the inner wall of the intermediate housing 1, on the the internal toothing of the adjustment gear 20 is also connected. The pressure field 86 thus formed over the high-pressure working space 35 presses the adjusting ring 14 against the radially opposite the pressure field 86 and the working space 35 Teeth 87 of the internal toothing 24 'of the adjustment gear 20. The pressure chambers are such that in the position of Fig. 3b with respect to the instantaneous pole M of the adjusting gear 20, a spring 36 which is sufficiently stressing arises.

Another possibility of reducing a gerotor pump with increasing Figures 4a, 4b and 5 show the rotational speed the adjustment gear, now designated 21, is designed as a partial internal gear with an only partially externally toothed adjusting ring 14 and one accordingly only partially internally toothed sheet metal ring 27. The partial outer toothing is 22 and the partial internal teeth designated 23. The two partial gears 22 and 23 serve for the slip-free rolling of the rolling circular cylinder surfaces 26 and 29 of the adjusting ring 14 and the housing in the control range.

On the housing is a sealing piece which extends over the width of the adjusting ring 14 89 arranged. The sealing piece 89 is cylindrical in cross section, in the exemplary embodiment circular cylindrical. The sealing piece 89 presses sealingly against it Opposite on the adjusting ring 14 trained as a counter-seal Thickening or tooth head-like point 88. Sealing piece 89 and thickening 88 are the partial toothings 22 and 23 arranged approximately diametrically opposite, so that between the sealing point 88, 89 formed in this way and the partial toothing 22, 23 over the outer circumferential surface of the adjusting ring 14 within a room 28 can build up a pressure on the outer circumference of the adjusting ring 14 pressing and using the adjusting ring as an adjusting piston against the force of one Control spring 32, which is comparable to the control spring 36 of the previous example, adjusted. The sealing piece 89 is, seen from the control spring 32, on the back the bead-shaped for articulating the control spring 32 on the adjusting ring Thickening 88, pressing against this thickening 88, mounted on the housing. On the back 85 of the sealing piece 89, a fluid pressure field acts between the Sealing piece back 85 and the housing is built and the sealing piece 89 firmly to the counter-seal 88 even when it moves under the seal 85 through firmly and tightly in the course of the adjustment of the adjusting ring 14.

In the pressure chamber 28 used as an adjusting cylinder over the outer circumference of the Adjustment ring 14 there is high pump pressure. The room 28 is on the outside The circumference of the adjusting ring 14 is approximately above the high-pressure groove opening 9 and is with the groove opening 9 by radial channels 9a recessed in the housing.

As can best be seen in the longitudinal section in FIG. 5, the sealing piece 89 formed by a sealing sleeve which is about an axis of rotation of the inner rotor 3rd parallel axis is rotatably mounted in the housing. Also connecting the expanding and compressing delivery cells of the pump by the rotating Connecting groove 45 and the two radial connecting grooves 46 and 47, as in In connection with the embodiment of Figure 1 have been described can be seen very well in FIG.

In the following Figures 6a to 9c, control pumps are shown, which are particularly suitable for use as high pressure pumps. The teeth of the inner rotor 51 by rollers 50, in the embodiment circular cylindrical Rollers formed, which are rotatably supported about axes parallel to the axis of rotation of the inner rotor 51 are. The inner rotor 51 is made in one piece with its drive shaft, as can be seen in particular in FIG. 6b.

In order to further reduce the deformation forces on the adjusting ring 14, it extends the teeth 52, 53 of the adjustment gear 20 over the entire width of the Adjustment ring 14. At the same time, this forms the ring gear-like housing part 55 the internal toothing 53 the intermediate housing between the two housing parts 1 'and 1 ".

In order to further reduce the load on the adjusting ring 14 in particular, the Adjustment ring 14 in the area of its outer peripheral surface, which is seen radially extends over the high pressure side of the pump, with the pressure of the high pressure side applied. The outer extending over the low pressure side of the pump The circumferential surface of the adjusting ring 14 is subjected to the low pressure. For this forms the adjustment gear 20 by means of its teeth 52, 53 pressure-tight chambers 56 'on the high pressure side and pressure tight chambers 56 "on the low pressure side.

The pressure-tight chambers 56 'and 56 "are via channels 58 in a housing part 57 (Figure 6b) with the pressure and suction spaces, i.e. with the high pressure and the Low pressure side of the pump connected. The channels 58 open into the tooth root areas the internal toothing 53 in the intermediate housing 55. 57 are in the housing part at least one connecting channel 60 to a slot opening 9 and one diametrically Opposing further connecting channel 61, which in the other groove opening 8th flows, provided.

The connecting channels 60 and 61 are connected by means of a control rotary valve 59 connected to channels 58. As shown in Figures 6b, 7a and 7b, this Control rotary valve 59 on an annular cylindrical rotating body in the housing part 57 rotatably received concentrically to the shaft 2 and in this recording controlled angle adjustable. By connecting channels 60 and 58 or 61 and 58 are accordingly the two slot openings 8 and 9 each with their rear, pressure chambers formed by the teeth 52, 53 of the adjustment gear 56 'and 56 "connected. These chambers 56' and 56" are thus below the Pressure of the slot opening assigned to them. The connection between the channels 60 and 58 or 61 and 58 is via throttles 74 and 75 in channels 60 and 61 and channel end portions 62 and 63, these channel end portions 62 and 63, in the exemplary embodiment simple bores, via connecting channels in the Rotary body of the control rotary valve 59 to the near the root circle of the internal toothing 53 opening channels 58 can be connected.

By turning the control rotary valve 59, the position of the high pressure and the low pressure chambers 56 'and 56 " are selectively chambers 56 'corresponding to the angular position of the control rotary valve and 56 ". In the exemplary embodiment, as can be seen in FIG. 7a, each in the vicinity of channels 60 and 61 there is another channel 77 and 79. Through the control rotary valve 59 or its rotary body and provided therein Control grooves are optionally channels 60 and 61 with their assigned Channels 58 or by means of control bores 76, 78 in the rotating body, the second pair of channels 77 and 79 connected to the leak spaces 80 to the tank 81. hereby the pressure chambers 56 ', 56 "are optionally printed or with the leakage spaces connected. By the pressure field in the teeth 52, 53 of the adjustment gear is changeable and by means of the control rotary valve 59 the resultant Force vector can also be changed in a controlled manner, at least with regard to its direction can, such that it laterally at the pivot point of the adjusting ring 14 If the momentary pole M points past, the force vector of the partial pressure field acts of the chambers 56 'and 56 "via the lever arm thus formed as the adjusting moment on the adjusting ring 14. The adjusting ring 14 rotates under the action of this Moments in its equilibrium position, in which the adjusting torque acting from outside and the moment of the working pressure field between the inside and the External rotor 51, 54 in equilibrium with respect to the respective instantaneous pulse M. stand. In this way, a demand-oriented funding rate can be achieved.

As shown in Figure 6b, is on the opposite of the drive stub At the end of the shaft 2, a flushing and regulating pump 72 is arranged, which in the case of a closed circuit via check valves 73 in the low pressure range greatly reduced pressure replaces the external leak oil. Furthermore, the control rotary valve and the housing part 57, as shown in FIG. 7a, the control bores 76, 77 and 78, 79 on which the chambers 56 'and 56 "with the leakage spaces Connect 80 to the fluid reservoir.

This control is known as commutation in orbital rotary piston motors. For example, if there are sixteen chambers 56 ', then thirty commutator holes provided in the control ring 59, which alternate with the suction and Pressure slot openings are connected. Because such controls basically are known, explanations are not required.

The angular adjustment of the control rotary valve 59 takes place by means of the in the figures 7a and 7b recognizable adjustment mechanism. A rocker arm 64 acts in one the rocker arm 41, 43 for adjusting the adjusting ring 14 in the exemplary embodiment of Figures 1a to 2 comparable way. The rocker arm 64 is in the housing limited pivotable about an axis that is parallel to the axis of rotation of the inner rotor 3 runs. With one free end it is connected to the ball bearing Rotating body of the control rotary valve 59 coupled. The simply straight rocker arm 64 is with its on the opposite side beyond its axis of rotation End hinged to two linear adjustment means 65, which the rocker arm 64 around its Swivel the axis of rotation back and forth. As a result, the rotary body of the control rotary valve 59 adjusted within a limited angular range.

FIGS. 8a to 8c show the three essential adjustment phases of the gerotor pump shown in Figures 6a to 7b. The pump according to Figures 8a to 8c is designed as a high-pressure reversing pump.

A self-regulating high-pressure pump is shown in FIGS. 9a to 9c. in the Embodiment of Figures 9a to 9c is explicitly only a zero stroke pump shown with a spring-loaded pressure piece 93 on one side 94 of the housing. It is only indicated on the side opposite the pressure piece 93 95 of the housing a second mirror image arrangement with a second, spring-loaded Thrust piece 93 '. By arranging the second spring-loaded The pump, as shown in FIGS. 9a to 9c, becomes pressure piece 93 ' a zero stroke pump for both directions of rotation. The adjusting ring 14 is against a flank via the pressure piece 93, on which a control spring 117 acts the external teeth 24 of the adjusting ring 14 in a position for maximum promotion biased in one direction. The control spring 117 acts in the manner of before described control springs 32 and 36. The second pressure piece 93 ', which also together with its control spring from the other side against a tooth flank of the External toothing 24 can be pressed, presses the adjusting ring 14 in the direction of the maximum funding in the opposite direction. Here is either a pressure piece 93 or the other pressure piece 93 ', depending on the desired direction of rotation, in side engagement with the external toothing 24. By the pressure pieces 93 and 93 'resilient resiliently pressed against their respective tooth flanks of the external toothing 24 are created, a self-regulating zero stroke pump according to the embodiments of Figures 3a to 4a. The zero stroke pump can do this be prepared that depending on the conditions at the installation site as left or clockwise pump can be installed by the housing for both directions of rotation is prepared and when installing the pump that for the desired Required direction of rotation including spring is installed. The pump could even be further developed into a reversing pump by using an adjusting means for example an actuating cylinder, pressing the position on the control spring 117 the control spring 117 changes in a controlled manner.

The adjustment ring 14 is, as already in connection with Figures 6a to 8c described, pressurized on its outer peripheral surface by the Teeth 24, 24 'of the adjustment gear with the high pressure side and the low pressure side connected chambers 91 'and 91 "are formed High pressure side and the low pressure side via channels 92 'and 92 ", in the foot area the external teeth 24 'open with the respective chambers 91' and 91 ". By at least one on the high pressure side, in the case of one Reversing pump thus on both sides, groove 96 provided in the housing connecting several of the chambers 91 'or 91 "to one another becomes special good, continuous adjustment of the external pressurization of the adjusting ring 14 reached.

As a result of the pressure prevailing in the pump work spaces 90 'and 90 " the force acting on the adjusting ring 14 is smaller than that caused by the pressure in the outer pressure chambers 91 'and 91 "force exerted on the adjusting ring 14, which in in the same way for the others with such pressure fields regulating themselves Pumping applies. This is achieved in that the pressurized acting radially Area in work spaces 90 'and 90 "is smaller than the pressurized radially acting surface of the pressure chambers 91 'and 91' '. The position of the adjustment ring 14 is thus determined by the resulting force vector due to the pressure in the Workrooms 90 'and 90 "and the pressure rooms 91' and 91" determined.

FIG. 10 shows a variant of the self-regulating zero stroke or reversing pump 9a-9c, but the teeth of the inner rotor again are integrally formed with the inner rotor. To manufacture the gearing between the adjusting ring 14 and the housing part 102 to facilitate External teeth 100 in the cross section of the adjusting ring 14 in a circular or partially circular shape. In this way, in particular, the manufacture of the counter teeth 103 on the housing 102 relieved. The counter toothing 103 is by means of a high-speed milling cutter shaped, the radius of which is equal to the radius 104 of the external teeth 100. The Rotary axis of the milling cutter, i.e. whose central longitudinal axis is on a hypocycloid guided with the same eccentricity 17 as the adjusting ring 14. The housing part 102 can thus initially in one piece in the die casting process without intermediate housing getting produced. The toothing 103 is then with the milling operation described worked out. This way it becomes a particularly economical one Production of the housing part having the internal toothing of the adjustment gear 102 possible.

In the exemplary embodiment according to FIGS. 10 to 13, the housing is in two parts the housing part 102 having the internal toothing and a cover part 111. The housing part 102 could in principle, as in the previously described exemplary embodiments also, be divided into two yourself again with one of the previously described Housing parts 55 comparable intermediate housing part.

In the exemplary embodiment according to FIGS. 10 to 13, the adjusting ring 14 again at least on one of its axial sides on a circumferential groove 45 which over the two other axial grooves 46 and 47, which in turn preferably in the cover-like Housing part 111 are formed in the area of the webs between the suction area 114 and the printing area 115 establishes a channel connection between the Squeeze chamber 112 and the cavitation chamber 113. The pump is in turn by means of a control spring 117 automatically cut off. As already in the embodiment According to FIGS. 9a-9c, the control spring 117 acts on the pressure element 93 External teeth 100 of the adjusting ring 14. In the formation of a self-regulating Reversing pump can again be provided a second control spring 117.

• inerhalb eines ersten Pumpendrehzahlbereichs eine schnell anwachsende Förderrate aufweist, die in erster Näherung proportional zur Drehzahl der Pumpe ist,
• innerhalb eines zweiten höheren Drehzahlbereichs sich schnell bis zum Erreichen einer voreingestellten Pumpendrehzahl abregelt und
• in einem sich an diese voreingestellte Pumpendrehzahl anschließenden dritten, noch höheren Drehzahlbereich wieder stärker als im zweiten Drehzahlbereich mit der Pumpendrehzahl steigt.

The control spring 117 can advantageously be developed into a control spring system with at least two series-connected springs. In this way, the pump according to the invention can be formed with a delivery characteristic in which the pump

• has a rapidly increasing delivery rate within a first pump speed range, which is in a first approximation proportional to the speed of the pump,
• quickly regulates itself within a second higher speed range until a preset pump speed is reached and
• in a third, even higher speed range following this preset pump speed, increases again more strongly with the pump speed than in the second speed range.

A funding characteristic of this type is particularly useful for motor vehicles advantageous in which a pump according to the invention from the motor vehicle engine is driven, the pump speed in a fixed relationship to the motor speed stands. Motor vehicles require in the lower engine speed range, i.e. from the start, immediately large amounts of oil. After reaching a predetermined engine speed and the associated pump speed and delivery is over the no or no speed range connected to the specified engine speed significant increase in the delivery rate of the pump is required. Would the funding rate would continue to increase unrestricted with increasing pump speed, would exceed the actual Need are promoted with a corresponding unnecessarily high Power requirement for the pump. After driving through this middle speed range, in general this is the main operating area of the engine that is used at higher engine speeds again require a higher oil production rate because with the higher engine speeds are accompanied by higher centrifugal forces at the points to be lubricated, for example on the crankshaft. To overcome this in importance the higher centrifugal forces, a higher oil pressure is required. Generally acts the three speed ranges to be distinguished in the case of passenger vehicles around the lower engine speed range from 0 to about 1,500 rpm, the adjoining main operating area of around 1,500 to around 4,000 Rpm and the third, higher engine speed range from about 4,000 U / min.

To achieve the desired funding characteristics, namely with a steep one Increase in the delivery rate in the lower speed range, one in comparison slow rise or even zero rise in the middle speed range and finally again a steeper increase in the upper speed range, will be a soft one first control spring and a harder second control spring, which together form a control spring system 117, connected in series. The rule spring 117 in FIGS. 9a-9c or FIG. 10, basically also the control spring 36 of the Figures 3a to 4b are used to achieve this funding characteristic both of the above-mentioned control springs. The control spring system 117 is under tension installed so that it hardly gives way in the lower speed range. at Exceeding the preload at the transition between the lower and the In the middle speed range, the soft first spring begins to compress until it reaches upper end of the middle speed range against the harder second control spring Stop comes to rest. With a further increase in speed, the delivery characteristic then determined by the harder second control spring.

When used as an oil pump for internal combustion engines, especially for Motor vehicles, the pump according to the invention can not only be used as a lubricant pump can be used, it can also advantageously be the oil for a hydraulic Valve clearance compensation and / or in particular as a pump for a valve timing adjustment be used. It can be used alone for each of the applications mentioned or used in combination. The invention is suitable for these purposes However, the pump is basically available in all of the described versions, because, due to their infinitely variable adjustability, everyone desired funding characteristics can be adjusted very precisely.

Claims (24)

1. A continuously variable annular gear pump comprising

   a) a stationary casing,

   b) an internal rotor (3) in the casing rotatably supported and driven by means of a shaft (2) and

   c) an external rotor (4) likewise rotatably supported, meshing with said internal rotor (3),

   d) the difference in the number of teeth of the gear ring running set (5) comprising said internal rotor (3) and said external rotor (4) being equal to unity, having a tooth shape in which a plurality of expanding and contracting displacement cells (7) each sealed off from the other materializes due to tooth tip contact (6), and

   e) kidney-shaped low and high pressure ports (8, 9) fixedly arranged laterally in the region of said displacement cells (7) being provided in the casing, said ports being separated from each other by webs (10, 11),

   f) and an adjusting ring (14) in which said external rotor (4) is supported at its outer diameter (13), said adjusting ring (14) being rollable by its outer circumferential or pitch circle (15) on an inner circumferential or pitch circle (16) for varying the angular position of the eccentric axis (eccentricity 17) of said annular gear running set (5) relative to the casing,

   g) wherein the difference in the diameters of said two circumferential or pitch circles (15, 16) equals twice the eccentricity (17) of said annular gear running set (5),

   characterised in that
   a complete or partial internal gear (24, 24'; 22, 23; 52, 53; 100, 103) is formed by an external toothing (24; 22; 52; 100) on said adjusting ring (14) and an internal toothing (24'; 23; 53; 103) on the casing side, said external toothing and said internal toothing being in meshing tooth engagement for rolling of said circumferential or pitch circles (15, 16) of said adjusting ring (14) and said casing with zero slip.
2. The annular gear pump as set forth in claim 1, wherein said circumferential or pitch circles (15, 16) of said adjusting ring (14) and said casing, rolling with zero slip on one another, are formed by the pitch circles of said internal gear (24, 24'; 22, 23; 52, 53; 100, 103), said pitch circles having the same eccentricity as said annular gear running set (5).
3. The annular gear pump as set forth in claim 1 or 2, wherein said internal toothing (24'; 23; 53; 103) featuring for flank engagement with said external toothing (24; 22; 52; 100) at least one, preferably precisely one, tooth more than said external toothing (24; 22; 52; 100), this difference in the case of only partial toothings being related to toothings imagined to be fully circumferential.
4. The annular gear pump as set forth in any of the previous claims, wherein teeth (24; 22; 52; 100) of said external toothing for forming said internal gear (24, 24'; 22, 23; 52, 53; 100, 103) are arranged only laterally on said adjusting ring (14), and wherein the remaining width of said adjusting ring (14) serves as a rolling cylindrical surface area (26, 29).
5. The annular gear pump as set forth in any of the previous claims, wherein for forming a zero-stroke pump a space (28) between a wall of said casing forming said inner circumferential circle (16) and a wall of said adjusting ring (14) forming said outer circumferential circle (15) is pressurized on the pressure side and said adjusting ring 14) is used as an adjusting piston (31) acting against a governor spring (32) for actuating the governing rolling movement of said adjusting ring (14).
6. The annular gear pump as set forth in any of the claims 1 to 4, wherein for forming a reversible pump means (40, 41, 42, 43, 44) are provided permitting mechanical actuation of said governing rolling movement of said adjusting ring (14) in both directions from the deadhead position (zero position) of said annular gear pump into the delivery position.
7. The annular gear pump as set forth in any of the previous claims, wherein between said adjusting ring (14) and said casing at least one sealed radially acting pressure field (86) connected to said high pressure is arranged, this pressure field sealingly urging said adjusting ring (14) at the opposite side as viewed radially by its tooth tips (87) or tooth-tip similar parts (88) against the tooth tips or tooth-tip similar parts (89) of said casing.
8. The annular gear pump as set forth in any of the previous claims, wherein on said casing at least one sealing member (89) is provided, said sealing member comprising on its rear (85) between said casing and said sealing member at least one sealed pressure field sealingly urging said at least one sealing member (89) against said tooth tip(s) or tooth-tip similar parts(88) of said adjusting ring (14), preferably by being exposed to high pressure.
9. The annular gear pump as set forth in any of the previous claims, wherein for forming a zero-stroke pump the pressure-building working space (35) is effective as an adjusting cylinder over said external rotor (4) on said adjusting ring (14) and a governor spring (36) is provided biased to move said adjusting ring (14) in the direction of maximum displacement.
10. The annular gear pump as set forth in any of the previous claims, more particularly for high working pressure, wherein said teeth of said annular gear running set (5) forming said displacement cells are configured on one of said two rotors (51, 54) as rollers (50), said rollers being rotatably mounted in said respective rotor (51, 54).
11. The annular gear pump as set forth in any of the claims 2 to 10, wherein the toothing (24, 24'; 22, 223; 52, 53; 100, 103) of said adjusting gear (20; 21) extends over the full width of said annular gear running set (5).
12. The annular gear pump as set forth in any of the claims 2 to 11, wherein said adjusting gear forms pressure-tight chambers (56', 56''), which are in a casing part (57) in connection via passages (58) with the pressure and suction spaces respectively of said pump.
13. The annular gear pump as set forth in any of the previous claims, wherein via a rotary control valve (59) said chambers (56', 56'') can be exposed both in number and in location each oppositely to high pressure and low pressure via passages (58, 60, 61, 62, 63).
14. The annular gear pump as set forth in claim 12 or 13, wherein the sum of surface areas exposed to high pressure in said pressure chambers (56', 56'') between said adjusting ring (14) and said casing has a smaller force effect than the sum of the surface areas exposed to pressure in the working chambers (35) in said pump toothing.
15. The annular gear pump as set forth in any of the claims 1 to 14, wherein for forming a zero-stroke pump a spring force strives to turn said adjusting ring (14) in the direction of maximum delivery; preferably said spring force being transmitted by means of a pressure member (93) to a tooth flank (94) of said external toothing (24; 100) of said adjusting ring (14).
16. The annular gear pump as set forth in any of the previous claims, wherein several tooth chambers (91'') located on the pressure side between said internal toothing of said casing part (55) forming said adjusting gear and said external toothing of said adjusting ring (14) are connected via passages (92') to the high pressure and said tooth chambers (91'') located correspondingly oppositely are connected to the low pressure via passages (92'').
17. The annular gear pump as set forth in claim 15 or 16, wherein said passages (92') are arranged so that they are cut off from and/or connected to the high pressure one after the other on a reduction in displacement by the rotatory movement of said adjusting ring (14).
18. The annular gear pump as set forth in any of the claims 15 to 17, wherein pressure members (93) are arranged on both sides (94, 95) of said casing, said pressure members (93) being actuatable by an adjusting cylinder for forming a reversible pump.
19. The annular gear pump as set forth in any of the claims 15 to 18, wherein in the region of said adjusting gear (20, 21) between said adjusting ring (14) and said casing (1; 55) grooves (96) are machined in the laterally arranged casing part (1') oriented circumferentially, said grooves connecting tooth chambers (91', 91'') of said toothing (24, 24') to each other on the highpressure side or on the low-pressure side or on both sides in a suitable length for tuning the hydraulic forces in these areas.
20. The annular gear pump as set forth in any of the claims 15 to 19, wherein a governor spring system (117) for generating the spring force comprises at least two springs, and in a first regulating range a soft spring characteristic having a small increase in force and in a subsequent second regulating range another characteristic having a larger increase in force is provided via the governor path.
21. The annular gear pump as set forth in any of the previous claims, wherein said adjusting ring (14) comprises on at least one axial side a circumferential groove (45) producing via at least two further axial grooves (46, 47) preferably arranged in a cover-like casing part (111) a passage connection between the entrapment space (112) and the cavitation space (113) in the web portions between said suction portion (114) and said pressure portion (115).
22. The annular gear pump as set forth in any of the previous claims, wherein said adjusting ring (14) comprises circular external toothing (100) on its outer diameter for forming said adjusting gear and said casing (102) is formed as an internal toothing (103) by rolling action of said adjusting ring (14) having said eccentricity (17) in common with that of said annular gear running set (5).
23. A method of producing the annular gear pump as set forth in claim 22, wherein said casing (102) is produced by die-casting and said tooth shape of said internal toothing (103) is formed by means of a milling cutter.
24. The annular gear pump as set forth in any of the previous claims, wherein said pump is used to supply a hydraulically actuated adjusting means for setting and varying the valve timing control of a valve-controlled internal combustion engine.

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