WO2016139230A1

WO2016139230A1 - Rotary piston pump

Info

Publication number: WO2016139230A1
Application number: PCT/EP2016/054392
Authority: WO
Inventors: Jan Körbelin
Original assignee: Jan Körbelin
Priority date: 2015-03-02
Filing date: 2016-03-02
Publication date: 2016-09-09
Also published as: DE102015203683A1

Abstract

The invention relates to a rotary piston pump (10) for conveying media, comprising a housing (50), wherein the housing (50) has an inlet opening (60) and an outlet opening (70), and a first rotor (20) and a second rotor (30), wherein the first rotor (20) and the second rotor (30) are each rotatably supported in the housing (50). The first rotor (20) and the second rotor (30) each have an at least largely circular main body (21, 31). The first rotor (20) and the second rotor (30) each also have at least two blades (25, 26, 35, 36), which protrude from the respective circular main bodies (21, 31) of the first rotor (20) and of the second rotor (30). At least two cut-outs in the form of a cycloid arc (22, 23, 32, 33) are formed on the circular main body (21, 31), which cut-outs in the form of a cycloid arc are formed at equal distances on the circumference of the circular main body (21, 31), wherein one of the blades (25, 26) of the first rotor (20) engages with one of the cut-outs in the form of a cycloid arc (32, 33) on the second rotor or one of the blades (35, 36) of the second rotor (30) engages with one of the cut-outs in the form of a cycloid arc (22, 23) of the first rotor (20).

Description

Rotary piston pump

The present invention relates to a rotary piston pump for conveying media, comprising a housing, wherein the housing has an inlet opening and an outlet opening, with a first rotor and a second rotor, wherein the first rotor and the second rotor are each rotatably mounted in the housing the first rotor and the second rotor each have an at least largely circular base body, the first rotor and the second rotor each having at least two wings, which protrude from the respective circular base body of the first rotor and the second rotor.

For compressing and conveying fluids, numerous forms of pumps are known. Rotary piston pumps, also referred to as rotary lobe pumps, rotary lobe pumps or Roots blowers, have, due to their comparatively simple, robust and cost-effective design for numerous Anwendungsf llle, from the compression of air to increase the performance of

Internal combustion engines, for pumping liquids or for use in the production of food.

From DE 307777 A a rotary piston pump for air supply of internal combustion engines is known, wherein a first rotor and a second rotor of the rotary piston pump suck in air and push out the compressed air in the direction of the combustion chambers of the internal combustion engine. In this case, the first rotor and the second rotor have a bone shape similar to the mathematical figure eight. Furthermore, from the prior art rotati- onskolbenpumpen known whose rotors are formed three leaves. From DE 1 902 634 U numerous other forms for the rotors of a rotary piston pump are also known.

A disadvantage of the known from the prior art solutions, however, is that there is either between the rotors or between one of the rotors and the housing has a relatively long contact area, so that the rotor is sensitive to jamming by a particle entry or the flow rate the rotors is low.

Object of the present invention is to develop a rotary piston pump such that the known from the prior art disadvantages are overcome, and the rotary piston pump at a high flow rate is insensitive to contamination and can be made compact.

The object is achieved by a rotary piston pump according to the invention with the features of claim 1. Characterized in that on the circular base body at least two recesses, which have the shape of cycloid arches, are formed and which at equal intervals on the circumference of the circular

Base body are formed, wherein one of the blades of the first rotor with one of the recesses on the second rotor or one of the blades of the second rotor is engaged with one of the recesses of the first rotor, it is possible, the delivery capacity with the same space compared to those from the state The art known rotary piston pumps to increase by the wings can continue to protrude beyond the circular base body and immersion of the wings is made possible in the recess of the other rotor. It is through the contour of the recess ensures that there is no jamming at a contact surface between the wing of one rotor and the recess of the other rotor. Under a recess in the form of a Zykloidbodens not only a mathematical exact Zykloidbogen is to be understood, but also a largely semicircular recess, in particular in the form of a Kardioidbogen or two mutually offset by a certain angle Kardioidhalbbögen. The circular basic shape of the basic body offers the advantage that the basic body can be produced particularly simply, for example in a simple turning process. In this context, a largely circular basic body is to be understood as meaning that the basic body can have certain production-related deviations from an ideal circular shape. For this purpose, deviations may be present, which originate from the recesses and possibly further recesses, in particular grooves, for receiving or fastening the wings in the case of a multi-part design and possibly existing transition regions on the recesses. The shape of the wing can be designed freely, as long as the wing has a tip and the distance of the tip of the circular base body is the same, the tip when rolling in the recess of the other rotor describes a Kardioidbogen, and the contact only at the top of the wing.

Since the blades can be freely designed within the limits specified above, the rotary piston pump can be adapted to special properties of the pumped media. Regardless of how the vanes are formed, the same performance is always achieved with incompressible media since an increase in the volume of the vane simultaneously reduces the volume returned by an equal volume. In particular, offer For example, a wing of maximum volume, as shown for example in FIG. 3 or FIG. 7, is particularly suitable for conveying compressible media, in particular gases, since only a very small amount is conveyed back here and the compressibility of the media does not lead to increased backflow. A shark fins or plate form such as shown in Fig. 4 or Fig. 5 always has a rectangular contact surface with approximately line contact and is therefore particularly well suited for contaminated liquid media, or an embodiment of the blade as in Fig. 8 or Fig. 11 represented, which always has an obtuse angle, and thus particularly well for heavily contaminated liquids, or semi-liquid media, such as those appear in the food industry. Such a rotor geometry is advantageous, for example, for conveying soup with pieces of meat, yoghurt with nuts, in medical technology for conveying liquids with cells or antibodies, or for conveying highly viscous media such as concrete or products with a high fiber content.

As a result of the shaping with a circular base body and wings protruding radially from the main body, a large part of the rotor mass, in particular with respect to a bone-shaped rotor known from the prior art, can be arranged in the center of the rotor, so that the rotary piston pump according to the invention is less sensitive to production-related or assembly-related imbalances and a more uniform flow rate is guaranteed.

In addition, the total mass of a rotor of the rotary piston pump according to the invention can be reduced in comparison to the rotors known from the prior art, whereby the rotor on the one hand is easier and on the other hand requires less material and thus can be produced more cheaply.

In addition, there is the advantage that the rotor of the same size takes up less volume in a working space bounded by the housing and the wings can thus promote more volume per revolution than the rotors known from the prior art. Thus, the rotary piston pump according to the invention with the same size achieves a higher flow rate than the known from the prior art rotary piston pumps.

It is also advantageous that with the same delivery volume as known from the prior art rotary piston pumps move the centers of the rotors closer to each other. Due to the closer center distance necessary for driving the rotors gears can turn out smaller, which further reduces the manufacturing cost.

It is also advantageous that with the same pump housing by selecting the rotors, the pump can be adapted to the appropriate medium to be conveyed and the rotors can be installed in principle mixed. This reduces the number of variants and thus lowers the costs in trade and sales.

By the measures listed in the dependent claims advantageous refinements and improvements of the independent claim specified rotary piston pump are possible.

A first advantageous development is that the wings each have a tip, wherein between the Spit- ze and an inner contour of the housing or between the tip and one of the recesses in the form of a cycloidal arc results in an approximately rectangular contact. This prevents pinching and grinding of foreign bodies, which can occur in the case of a contact surface between the rolling bone-shaped rotors known from the prior art. As a result, the wear on the housing, on the wings and on the recesses of the circular base body can be reduced. Under an approximately linear contact surface should be understood in this context that, although theoretically between a finely thin tip and the inner contour of the housing results in a linear contact, but the wings have certain material thicknesses and the tip is not ideally shaped, so that real Contact surface results. Depending on the configuration, the tip may have direct contact with the inner contour of the housing or there may be a small gap between the tip and the housing.

Alternatively, it is advantageously provided that the wings each have a contact arc, wherein the contact arc has an arc length of 5 ° to 20 ° relative to a contact surface of the contact arc with an inner contour of the housing. As a contact arc to be understood in this context, the housing facing the end of a wing, which has approximately the same radius as the inner contour of the housing. In a contact arc with an arc length of 5 ° to 20 °, the rolling surfaces can be kept so small that the risk of jamming and the associated Verschscheiß are kept low. It is particularly advantageous if the contact surface of the contact arc with an inner contour of the housing has an arc length of 8 ° to 12 °, since such a contact sheet a represent a particularly advantageous compromise between sealing along the contact sheet and a low risk of jamming. Depending on the configuration, the contact arc may be in direct contact with the inner contour of the housing, or there may be a small gap between the contact arc and the housing.

Due to the largely "squeeze-free" promotion, so by an embodiment in which short crimp between the circular bodies of the first rotor and the second rotor and between the wings and the inner contour of the housing are formed, the pump is insensitive and robust against particle entry and overall In this case, in particular in the case of a three-bladed rotor and / or by appropriate shaping of the blades, unrolling of the circular basic bodies of the rotors can be completely avoided, so that pinching at this point is ruled out The elimination of filters, on the one hand, reduces the costs for the rotary piston pump, but on the other hand has other advantages, such as increased availability of the pump, since downtimes for filter cleaning are avoided derstand when flowing through an inlet-side filter is eliminated. In addition, for many applications it may be advantageous to dispense with a filter, since a filter often provides ideal conditions for the accumulation and proliferation of bacteria and the proposed rotary piston pump offers significantly better hygiene.

A further advantageous development is that a distance between a center axis of the first rotor and a center axis of the second rotor is smaller than the 1,333- is a length from the central axis of the first rotor to the tip or to the contact arc. Due to the recesses in the circular basic bodies, the two rotors can have longer wings for the same size, so that with similarly sized housings a significantly higher delivery rate can be achieved. It is particularly advantageous if the distance is less than 1.2 times, as can be realized in this way particularly compact rotary piston pumps. Thus, in comparison to the known rotary piston pumps, the same delivery rate can be displayed at a lower weight or smaller size, or at the same weight or the same size of the rotary piston pump, a higher delivery rate can be achieved.

According to an advantageous embodiment, it is provided that the tip or the contact arc have a sealing lip. By a sealing lip, the losses can be reduced and the efficiency of the rotary piston pump can be increased. The sealing lip has direct contact with the inner contour of the housing, so that a possibly existing gap is closed. The sealing lip can be configured, for example, as a rubber sealing lip, but alternatively also other sealing forms, in particular brush seals, are conceivable.

A preferred embodiment has in the recesses of the circular base body insert elements which have a higher hardness than the circular base body and the wings. As a result, a defined wear on the tips or the contact arcs of the wings can be achieved, while the circular base body is largely not subject to wear. As a result, it can be quickly detected, for example, in a revision of the rotary piston pump, if an exchange of the rotors is necessary. Alternatively, the Insertion elements are also designed as particularly soft and especially interchangeable insert elements, so that the wear occurs defined on the insert elements, which then indicates in a revision either the replacement of the rotors or the replacement of the insert elements.

A further advantageous development is that the first rotor and / or the second rotor are designed in several parts, wherein a non-destructive separation between one of the circular base body and one of the associated wings is provided. This allows the wings to be replaced, making a revision of the rotary piston pump very easy. In addition, the wings can also be replaced to adapt the rotary piston pump to different media.

It is particularly advantageous if the wings are made of a softer material than the circular base body. As a result, wear occurs preferably on the wings, which can then be replaced in a revision of the rotary piston pump. In addition, the wings should also be softer than the inner contour of the housing, so that a wear preferably occurs on the wings here.

A further advantageous development is that at least on one of the circular base body, a groove for receiving one of the wings is formed. As a result, a particularly simple, stable and accurate recording of the wings on the circular base body is possible. Alternatively, a bulge can be provided on the circular base body, via which a wing can be centered on the base body. A further advantageous development is that the wings are formed as a hollow body. As a result, the weight of the wings can be reduced and the mass of the rotors are concentrated in the circular base body. This ensures that the rotor is less sensitive to production-related or assembly-related imbalances and rotates particularly uniformly. It is particularly advantageous if the wings are made as deep-drawn or injection-molded parts made of plastic. Thus can be produced particularly easily and inexpensively interchangeable wings, which also can be designed so soft that they rest against the inner contour of the housing or on the recesses of the circular body and thus achieve a high sealing effect.

According to a further advantageous development, it is provided that the wings are designed in the form of a plate protruding radially from the circular base body. The radially emerging from the circular body plates require very little space and fill a very small volume in a ^' limited by the inner contour of the housing working space. As a result, a comparatively large volume per revolution can be promoted. Due to the small volumes of plates as wings, moreover, a very uniform delivery of a fluid with a very low pressure pulsation can be achieved. In addition, thus can be easily achieved the already described positive configuration of a wing with a tip.

According to an alternative development, it is provided that the wings have approximately the shape of a parabola or a shark fin. By an approximately parabolic or shark fin shape can also be represented a wing which has a peak. In the exemplary embodiments, no mathematical exact parabola is shown, but two intersecting epicycloid arcs, wherein the

Intersection of the two epicycloid arches forming the tip. Such an embodiment should be encompassed by the term approximately parabolic. Compared to a plate, however, an approximately parabolic or shark-fin-shaped wing can be made substantially more rigid, which can be advantageous in particular when conveying highly viscous fluids.

According to a further alternative embodiment it is provided that the wings have a blade shape. A blade shape offers the possibility of forming a wing with comparatively little use of material. It is particularly advantageous if the wings are designed in the manner of a spring plate, so that the paddle-shaped spring element is pressed with a slight bias against the inner contour of the housing. As a result, a seal between the blade and the housing can be realized in a simple manner. Depending on the direction of rotation, the blade shape has further advantages. Thus, in the case of a direction of rotation, as shown in FIG. 11, the blades can carry particles or impurities particularly well on the inner contour of the housing and feed them to a point on the blade base, so that the wear is reduced. In one direction of rotation, as shown in FIG. 12, an overload function can be integrated into the rotary piston pump by the spring biasing of the blade, so that the blade springs back on exceeding a defined pressure on the outlet side and thus enables a pressure reduction, so that no further fluid is conveyed in the direction of the outlet side. According to a further advantageous development, it is provided that the first rotor and the second rotor are designed as dreiflüge- lige rotors, each having three recesses and three wings. In principle, all embodiments of the rotary piston pump shown in the exemplary embodiments of the invention may each be formed with rotors having two, three or more vanes. A three-bladed rotor has the advantage over a two-bladed rotor that the unrolling areas are smaller at the surfaces of the circular base bodies meeting one another, thereby also reducing the risk of jamming by particles or contaminants in the contact area of the circular base bodies. The wings can also be designed so that a rolling of the circular base body is completely avoided each other, so that deadlocks can not occur.

In an advantageous further development of the invention, it is provided that the blades have at least one trough in the direction of rotation, wherein the trough base is set back relative to the edge regions of the wing. By trailing in the direction of rotation trough impurities in the pumped medium can be concentrated in the trough. This reduces the risk of jamming of contaminants, in particular of stones or other solid particles. In addition, such impurities can be removed particularly well by the centrifugal forces, when an output of the rotary piston pump is arranged in a radial extension to this trough.

According to a further advantageous embodiment, it is provided that the wings are formed axially symmetrical, with a point on the axis of symmetry with respect to the axiomatic axis. is set back al outside edge regions of the wing. By a symmetrical wing with a recessed center opposite the center, a centering of the medium to be conveyed is ensured. In addition, the bearing of the rotors can be improved so that mass forces cancel in such an embodiment of the wings substantially. Furthermore, it is achieved that the wings self-center, since in each case at least one wing is engaged with a recess on the circular base body and thus is given a continuous guidance of the rotor. This also improves the runflat performance if the drive for one of the rotors fails and the second rotor is then "dragged" by the flowing medium and the remaining rotor and the overlap angle is increased, thereby reducing the production losses.

In a preferred embodiment it is provided that the outer edge regions of the wing in the form of a bow line, in particular a circular arc line, are interconnected or have an arrow shape. By a curved line or an arrow shape results from the respective axially outer edge regions of the wings a continuously increasing overlap, whereby the pressure oscillations are reduced in the rotary piston pump and a more uniform delivery and a more uniform pressure build-up are possible.

It is particularly advantageous if the symmetry axis or the depression bottom is set back relative to the outer edge regions in the direction of rotation of the rotor by 5 ° to 30 ° rotation angle. Particularly preferred is a range of 10 ° to 20 °, in particular 15 ° rotation angle. With a smaller offset than 5 ° rotation angle, the advantages of self-centering and the removal of impurities can only be be realized. With an offset of more than 30 ° rotation angle between the edge regions and the trough base or the axis of symmetry very long wing tips, which can lead to a reduction in mechanical strength and thus to damage the wings.

In a further advantageous development it is provided that the housing has a substantially elliptical basic shape, wherein the housing at the major apexes of the ellipse each have a deviating from the substantially elliptical basic shape part circular shape, wherein the pitch circle section over an angular range of more than 120 ° extends. In one embodiment of the rotor with three wings, the wings each have a distance of 120 ° to each other. By partial circle sections of more than 120 °, a section is created in which the chambers are closed continuously. Thus, the wing tip of the wing following in the direction of rotation already comes into contact with the pitch circle section, while the preceding wing leaves the chamber delimited by the pitch circle section and the two wings. Thus, at least one wing of the rotor always bears against the inner contour of the housing. Due to the trough in the wing, the pitch circle section must be greater than 120 °, in order to prevent leakage through a gap in the radial extension of the trough and thus to allow complete sealing of the chamber.

The invention will be explained below with reference to various preferred embodiments with reference to the accompanying figures. The same components or components with the same function are identified by the same reference numerals. Show it: Fig. 1 is a known from the prior art first embodiment of a rotary piston pump;

Fig. 2 shows another embodiment of already from the

Prior art known rotors for a rotary piston pump;

3 shows a first embodiment of a rotor of a rotary piston pump according to the invention;

4 shows a further embodiment of a rotor of a rotary piston pump according to the invention;

5 shows a further embodiment of a rotor of a rotary piston pump according to the invention;

6 shows a further embodiment of a rotor of a rotary piston pump according to the invention;

7 shows a further embodiment of a rotor of a rotary piston pump according to the invention;

8 shows a further embodiment of a rotor of a rotary piston pump according to the invention;

9 shows an embodiment of a three-winged rotor of a rotary piston pump according to the invention;

Fig. 10 shows another embodiment of a dreiflügeligen

Rotor of a rotary piston pump according to the invention;

Fig. 11 shows another embodiment of a dreiflügeligen

Rotor of a rotary piston pump according to the invention; 12 shows a further embodiment of a three-bladed rotor of a rotary piston pump according to the invention;

13 shows an embodiment of a rotary piston pump according to the invention with two double-bladed rotors;

14 shows an embodiment of a rotary piston pump according to the invention with two three-bladed rotors;

FIG. 15 shows an exemplary embodiment of a three-winged, self-centering rotor; FIG.

Fig. 16 shows a second embodiment of a three-bladed, self-centering rotor

Fig. 17 two self-centering rotors in mutual engagement;

18 shows a second embodiment of two self-centering rotors in mutual engagement.

19 shows a third embodiment of two self-centering rotors in mutual engagement. and

Fig. 20 shows an embodiment of a rotary piston pump according to the invention with arranged in the housing, self-centering rotors.

In Fig. 1, a known from the prior art rotary piston pump 10 is shown in the manner of a Roots compressor. The rotary piston pump 10 has a housing 50 into which an inlet opening 60 and an outlet opening 70 are introduced. The housing 50 has an inner contour 51, which limits a working space 52 of the rotary piston pump 10. In the housing 50, a first rotor 20 and a second rotor 30 are each rotatably mounted. A fluid flowing from the inlet opening 60 into the working space 52 of the rotary piston pump 10 is compressed by the rotational movement of the rotors 20, 30 and conveyed through the outlet opening 70.

FIG. 2 shows further known embodiments of rotary piston pumps 10, in which the rotors 20, 30 are star-shaped as in FIG. 2a or oval-shaped as in FIG. 2c. From Fig. 2e, a rotary piston pump 10 is known, which has a first rotor 20 and a second rotor 30, wherein the first rotor 20 and the second rotor 30 each have a largely circular basic shape 21, 31, and wherein on the first rotor 20 and the second rotor 30 are each two wings 25, 26, 35, 36 are formed, wherein on the respective circular base bodies 21, 31 of the rotors 20, 30 V-shaped recesses 17 are provided.

In Fig. 3, a first embodiment of a rotor 20, 30 of a rotary piston pump 10 according to the invention is shown. For reasons of clarity, only the first rotor 20 of a rotary piston pump 10 according to the invention is shown in FIGS. 3 to 12. In a representation of a geometrically identical or mirrored on a central axis 29 second rotor 30 has been omitted for the sake of clarity. The first rotor 20 has a circular main body 21, in which two recesses 22, 23 offset by 180 ° to each other are introduced. Further, two offset by 180 ° to each other arranged wings 25, 26 are formed on the circular base body 21, which are arranged rotated by 90 ° to the recesses 22, 23 are. The wings 25, 26 have approximately the shape of a parabola 42 or two intersecting Epizykloidbogen, wherein the intersection of the Epizykloidbogen a tip 45 of the wings 25, 26 forms. The first rotor 20 is rotatably supported about a central axis 29 in the housing 50. The epicycloid arc runs in such a way that only the tip 45 of the epicycloidal arc is in contact with the inner contour 51 of the housing 50 or the recess 22, 23 of the second rotor 30, thereby forming an approximately linear contact surface 53.

4, a further embodiment of a rotor 20, 30 of a rotary piston pump 10 according to the invention is shown. In most of the same structure to the embodiment of FIG. 3, the rotor 20 wings 25, 26, which shark fin-shaped 43 are formed. The shark fin shape 43 results from the intersection of a straight line, which is turned radially through 90 ° to the recesses, through the central axis 29 of the circular main body 21, which intersects with an epicycloidal arc. At the same time the intersection of the straight line with the epicyclic arc forms the tip 45. The epicycloid arc runs in such a way that only the tip 45 of the epicycloid arc is in contact with the inner contour 51 of the housing 50 or the recess 22, 23 of the second rotor 30, thereby forming an approximately linear contact surface 53.

FIG. 5 shows a further exemplary embodiment of a rotor 20, 30 of a rotary piston pump 10 according to the invention. In largely the same structure as in the examples shown in FIGS. 3 and 4, only the differences will be discussed below. The rotor 20 has wings 25, 26 in the form of radially out of the circular main body 21. passing plates 41, which are fixed in grooves 28 of the circular base body 21. In this case, the grooves 28, as shown at one of the circular base body 21 facing the end of the blade 26, be formed in the simplest case as a straight grooves 28 in the circular base 21 introduced grooves 28, wherein the wing 26 is clamped in the groove 28. Alternatively, as shown at one of the circular base body 21 facing the end of the blade 25, a T-shaped configuration of the groove 28 is possible, whereby a positive and particularly stable connection between the circular base body 21 and the wing 25 is possible. Alternatively, other connection forms between the wings 25, 26 and the circular base 21 are possible.

Further, in at least one of the recesses 22 on the circular base body 21, preferably on all recesses 22, 23, an insert element 47 is provided, which has a greater hardness than the circular base body 21, 31 or the wings 25, 26. This wears out on contact of the tip

45 with the insert member 47, the softer tip 45, so that wear occurs only at defined locations such as the tip 45 and thus can be easily controlled. Such insert elements 47 are not limited to the embodiment of FIG. 5, but may be provided in all rotors 20, 30 of the rotary piston pump 10 according to the invention. Furthermore, the wing 26 has a sealing lip at its tip 45

46 in the form of a rubber seal lip. Such sealing lips 46 may also be provided in all embodiments shown here to increase the delivery rate and to reduce losses. FIG. 6 shows a further exemplary embodiment of a rotor 20, 30 of a rotary piston pump 10 according to the invention. In largely the same structure as in the embodiment of FIG. 3 will be discussed below only the differences. The wings 25, 26 each have the shape of two Epizykloidbogen, which, however, do not intersect, but are connected by a contact arc 48, which has largely the same radius as the inner contour 51 of the housing 50. The length of the contact arc is approximately 10 ° relative to a contact surface 53 of the contact arc 48 with the inner contour 51 of the housing. The epicycloid arc runs in such a way that only the contact arc 48 or the tips 45 of the epicycloid arc are in contact with the inner contour 51 of the housing 50 or the recess 22, 23 of the second rotor 30, thereby forming the contact surface 53. The wings 25, 26 may be designed to reduce the masses as a hollow body 49, for example as a plastic deep-drawn part or as a plastic injection-molded part. In addition, a nondestructive separation between the wings 25, 26 and the circular base body 21 is provided, so that the wings 25, 26 can be replaced.

FIG. 7 shows a further exemplary embodiment of a rotor 20, 30 of a rotary piston pump 10 according to the invention. In the case of largely the same construction as in the embodiment according to FIG. 6, only the differences will be discussed below. The epicyclic arc of the wings 25, 26 have a slightly larger radius, so that between the two circular base bodies 21, 31 of the two rotors 20, 30 no more rolling surfaces are more and the contact exclusively between the contact sheets 48 and the respective recesses 22, 23, 32, 33 takes place. This makes a rotary piston pump 10 according to the invention particularly insensitive to particles and Impurities. According to this embodiment, it is provided that on the circular base body 21 bulges are provided, via which the wings 25, 26 at the circular

Main body 21 are centered.

FIG. 8 shows a further exemplary embodiment of a rotor 20, 30 of a rotary piston pump 10 according to the invention. In the case of largely the same construction as in the embodiment according to FIG. 7, only the differences will be discussed below. The wings 25, 26 are formed largely plate-shaped, wherein at the respective, the circular base body 21 opposite ends of the wings 25, 26 contact sheets 48 are formed. The length of the contact arches 48 and the geometry of the recesses 22, 23 are the same in the two embodiments according to FIG. 7 and FIG. 8, so that a mixed installation of these embodiments of the rotors 20, 30 is conceivable without conversion.

9 shows an exemplary embodiment of a three-winged rotor which can be used as first and second rotor 20, 30 in a rotary piston pump 10 according to the invention. The three-bladed rotor 20, 30 has a circular

Base 21, 31, in which three offset by 120 °, recesses 22, 23, 24, 32, 33, 34 are formed. The three-bladed rotor 20, 30 further comprises three wings 25, 26, 27, 35, 36, 37, which also offset by 120 ° to each other, on the circumference of the circular base body 21, 31 and offset by 60 ° to the recesses 22nd , 23, 24, 32, 33, 34 are arranged. The wings 25, 26, 27, 35, 36, 37 are formed as plates 41, wherein also other of the previously illustrated embodiments of the wings 25, 26, 27, 35, 36, 37 according to FIGS. 3 to 8 are conceivable , The plates 41 have tips 45 which are in contact with the Inner contour 51 of the housing 50 can occur. The rotor 20, 30 according to FIG. 9 can be realized both in one piece and in several parts, in particular according to the embodiment in FIG. 5, wherein a separation between the wings 25, 26, 27, 35, 36, 37 and the circular main body 21 , 31 is provided.

10 shows a further exemplary embodiment of a three-flighted rotor 20, which can be used as the first rotor 20 and the second rotor 30 in a rotary piston pump 10 according to the invention. In most of the same structure to the embodiment of FIG. 9 will be discussed below only the differences. The wings 25, 26, 27 are formed in shark fin form 43 in this embodiment. As a result, a higher rigidity is achieved than in the case of wings 25, 26, 27 in the form of a plate 41, which is advantageous in particular when conveying highly viscous media.

FIGS. 11 and 12 show a further exemplary embodiment of a rotor 20. The embodiments in FIGS. 11 and 12 differ only in the direction of rotation of the rotor 20. Three recesses 22, 23, 24 are formed on the circular base body 21 , which are each offset by 120 ° to each other. Further, wings 25, 26, 27 are arranged in the form of spring plates on the circular base body 21, wherein the tip of the spring plate is rotated in about 60 ° to the closest to the central axis 29 point on the recess 22, 23, 24 is arranged. Depending on the direction of rotation, the spring plate acts either as a kind of blades, which is pressed against the inner contour 51 of the housing 50, or as a kind of leaf spring, wherein the wing 25 springs from a defined pressure at the outlet opening 70 of the rotary piston pump 10 and the inner contour 51st of the housing 50 lifts off, so that an overload function can be integrated into the rotary piston pump 10.

FIG. 13 shows a rotary piston pump 10 according to the invention. The rotary piston pump 10 has a housing 50 with an inlet opening 60 and an outlet opening 70. In the housing 50, the first rotor 20 and the second rotor 30 are each rotatably supported. The first rotor 20 and the second rotor 30 each have an at least largely circular base body 21, 31, wherein the first rotor 20 and the second rotor 30 each have two wings 25, 26, 35, 36, which from the respective circular base body 21st , 31 of the rotors 20, 30 protrude. Two recesses 22, 23, 32, 33 are formed on the circular base bodies 21, 31, which are formed at equal intervals on the circumference of the circular base body 21, 31, ie offset by 180 ° relative to one another. In this case, the wing 35 of the second rotor 30 is in engagement with the recess 23 of the first rotor 20. The tip of the wing 25, 26, 35, 26 has approximately a linear contact surface 53 with the inner contour 51 of the housing 50 or the recess 23 of the first Rotor 20. Through the recesses 22, 23, 32, 33, a distance between the central axis 29 of the first rotor 20 and the central axis 39 of the second rotor 30 can be kept small. Thus, the distance A shown is approximately 1.15 times the length L between the central axis 39 of the second rotor 30 and the recess 23 facing the tip 45 of the wing 35 of the second rotor 30. In comparison, the distance is at the out According to the prior art rotors according to the exemplary embodiment in FIG. 1, the 1.333 times. Thus, the rotary piston pump 10 according to the invention can be built compact and lighter at the same capacity. FIG. 14 shows a further exemplary embodiment of a rotary piston pump 10 according to the invention. The rotary piston pump 10 is designed with two three-bladed rotors 20, 30, whereby a direction of rotation of the rotors 20, 30 is represented by the arrows in FIG. 14. The rotary piston pump 10 has a housing 50 with an inlet opening 60 and an outlet opening 70. In the housing 50, the first rotor 20 and the second rotor 30 are each rotatably supported. The first rotor 20 and the second rotor 30 each have an at least largely circular base body 21, 31, wherein the first rotor 20 and the second rotor 30 each have three wings 25, 26, 27, 35, 36, 37, which from the respective circular base body 21, 31 of the rotors 20, 30 protrude. Three recesses 22, 23, 24, 32, 33, 34 are formed on the circular base bodies 21, 31, which are formed at equal intervals on the circumference of the circular base body, ie offset by 120 ° from each other. In this case, the wing 27 of the first rotor 20 is in engagement with the recess 32 of the second rotor 30. The tip 45 of the wings 25, 26, 27, 35, 36, 37 has approximately a linear contact surface 53 with the inner contour 51 of the housing 50 or the recess 32 of the second rotor 30. By the recesses 22, 23, 24, 32, 33, 34, a distance between the central axis 29 of the first rotor 20 and the central axis 39 of the second rotor 30 can be kept small.

FIG. 15 shows a first exemplary embodiment of a self-centering rotor 20 for a rotary piston pump 10 according to the invention. The rotor 20 has a circular base body 21 with three recesses 22, 23 and 24 and three wings 25, 26 and 27. In this case, between the outer edge regions 82 and 83 of the wing 26, a depression 86 is formed, which in the direction of rotation with respect to the outer lying edge regions of the wing 26 is set back. In this case, a trough bottom 87 of the trough 86 forms the point which is recessed furthest opposite the axially outer edge regions 82 and 83 of the wing 26. At the same time, the edge regions 82 and 83 convey the medium in the rotary piston pump 10 away from the edge regions 82, 83 in the direction of the depression 86, so that a volumetric flow of the conveyed medium is also provided is centered. By trailing in the direction of rotation trough 86 impurities can be concentrated in the medium and selectively discharged. As a result, the risk of jamming of impurities and hard particles, which can otherwise lead to premature wear or in the worst case to failure of the rotary piston pump 10, reduced. In this case, an end line of the wing 26 in the form of a circular arc line 84, so that the edge regions 82 and 83 in front of the center of the wing 26 with the housing 50 or a recess on a further rotor 30 engage. As a result of the circular arc line, starting from the respective axially outer edge regions 82 and 83 of the blade 26, a continuously increasing overlap results, whereby pressure oscillations in the rotary piston pump 10 are reduced and a uniform pressure build-up or uniform delivery of the medium is achieved. The other wings 25 and 27 of the rotor 20 are constructed in the same shape. The contour of the recesses 22, 23, 24 is adapted to the contour of the wings 25, 26, 27, wherein the edge regions of the recesses 22, 23, 24 have a shape corresponding to the wings and also in the form of a curved line or in an arrow shape are.

FIG. 16 shows a further exemplary embodiment of a self-centering rotor 20. For essentially the same In the same way as the rotor 20 in FIG. 15, the front line on the wings 25, 26 and 27 in arrow shape 85 is formed axially symmetrical to a central axis 81 of the respective wings 25, 26 and 27. In this case, the trough base 87 of the trough 86 lies on the axis of symmetry 81 of the wings 25, 26 and 27. The trough base 87 is set back in the direction of rotation about 15 ° with respect to an engagement point of the outer edge regions 82 and 83 of the wings. This results in a slowly increasing overlap between the vanes 25, 26 and 27 and the housing 50 or between the vanes 25, 26 and 27 and a recess 32, 33, 34 of the other rotor 30 shown in FIG.

In Fig. 17, two self-centering rotors 20 and 30, each with two wings 25, 26, 35, 36 and two recesses 22, 23, 32, 33 are shown. In this case, the wing 36 of the second rotor 30 engages in the recess 23 of the first rotor 20. The curved shape of the wings 25, 26, 35, 36 can be seen particularly well on the wing 25 in this illustration. The trough 86 of the wing 25 is set back in the direction of rotation with respect to the edge regions 82 and 83 of the wing 25, so that upon further rotation of the rotors 20, 30 first the edge regions 82 and 83 engage in the recess 33 of the second rotor 30 and the trough 86th only with an offset of about 10 to 15 degrees follows.

In Fig. 18, two rotors 20, 30 are shown, which are each formed as dreiflügelige rotors and each having three recesses 22, 23, 24, 32, 33, 34 and three wings 25, 26, 27, 35, 36, 37 have. The wings 25, 26, 27, 35, 36, 37 have the shape described in Fig. 15 with a front line in the form of a circular arc line 84 and a trough 86 which is set back relative to the edge regions 82 and 83 In Fig. 19, another embodiment of two mutually engaging rotors 20, 30 is shown. With essentially the same structure as the rotors described in the preceding figures, the vanes 25, 26, 27, 35, 36, 37 each have two troughs 86a, 86b, the vanes 25, 26, 27, 35, 36, 37 in FIG the center, ie on its axis of symmetry 81, have a survey which rises approximately to the level of the outer edge regions 82 and 83 of the wings 25, 26, 27, 35, 36, 37. This is particularly advantageous when the rotary piston pump 10 has several Auslassöff openings 70, wherein the outlet openings are preferably each arranged in the radial extension of the wells 86a, 86b. Thus, several volume flows of the medium can be centered on multiple outputs of the rotary piston pump 10, whereby an efficient delivery of media containing solids and / or solids is possible.

FIG. 20 shows the arrangement of two self-centering rotors 20, 30 in a housing 50. The housing 50 has a substantially elliptical basic shape 56 with two main peaks 57 and 58. In the areas of the main vertex 57 and 58, the housing 50 has a shape deviating from the ellipse 56, wherein the housing 50 is formed in each case on the main vertex 57, 58 in the form of a partial circle section 59. The partial circle sections 59 each have an angle α, β of more than 120 °, preferably 135 °. In cooperation with the trailing troughs 86, at least temporarily a chamber 55 is formed in each case in the region of the main vertex 57, 58, which is delimited by the pitch circle section 59 and the wings 37 and 36, whereby the vane 36 only releases from the pitch circle section 59 when the vane 37 is already engaged with the pitch circle portion 59 has entered. At any given time, at least one vane 35, 36, 37 of the second rotor 30 abuts on the pitch circle section 59b and at least one vane 25, 26, 27 of the first rotor 20 adjusts on the pitch circle section 59a of the housing 50.

Through the circular arc line 84 or the arrow 85 at the

Tip of the wings 25, 26, 27, 35, 36, 37 is thus achieved in conjunction with the pitch circle portion 59, a continuous opening and closing of the chamber 55, whereby a very uniform delivery of the medium is achieved and a pressure pulsation in the rotary piston pump 10 is avoided ,

Claims

Claims :

1. rotary piston pump (10) for conveying media, with

a housing (50), the housing (50) having an inlet opening (60) and an outlet opening (70), and a first rotor (20) and a second rotor (30), the first rotor (20) and the second rotor (30) are each rotatably mounted in the housing (50), wherein

the first rotor (20) and the second rotor (30) each have an at least largely circular base body (21, 31), wherein

- The first rotor (20) and the second rotor (30) each have at least two vanes (25, 26, 35, 36), which from the respective circular base body (21, 31) of the first rotor (20) and the second rotor (30)

characterized in that

on the circular base body (21, 31) at least two recesses in the form of a Zykloidbogens (22, 23, 32, 33) are formed, which are formed at equal intervals on the circumference of the circular base body (21, 31), wherein

one of the wings (25, 26) of the first rotor (20) with one of the recesses in the form of a cycloidal arc (32, 33) on the second rotor or one of the wings (35, 36) of the second rotor (30) with a recess in Form of a cycloidal arc (22, 23) of the first rotor (20) is engaged.

2. rotary piston pump (10) according to claim 1, characterized in that the wings (25, 26, 35, 36) each have a tip (45), wherein between the tip (45) and an inner contour (51) of the housing (50 ) or between the tip (45) and one of the recesses in the form of a cycloidal arc (21, 31) an approximately linear contact surface (53) is formed.

3. rotary piston pump (10) according to claim 1, characterized in that the wings (25, 26, 35, 36) each have a contact arc (48), wherein the contact arc (48) has an arc length of 5 ° to 20 °, preferably 8 ° to 12 °, based on a contact surface (53) of the contact arc (48) having an inner contour (51) of the housing (50).

4. rotary piston pump (10) according to claim 2 or 3, characterized in that a distance (A) between a central axis (29) of the first rotor (20) and a central axis

(39) of the second rotor (30) is less than 1.333 times, preferably less than 1.2 times, a length (L) from the central axis (29) of the first rotor (30) to the point

(45) or the contact sheet (48).

5. rotary piston pump (10) according to any one of the preceding claims, characterized in that the tip (45) or the contact arc (48) has a sealing lip (46), in particular a rubber sealing lip.

6. rotary piston pump (10) according to any one of the preceding claims, characterized in that in the recesses (22, 23, 32, 33) of the circular base body (21, 31) insert elements (47) are provided which have a greater hardness than the circular Base body (21, 31) and the wings (25, 26, 35, 36).

7. rotary piston pump (10) according to one of the preceding claims, characterized in that the first rotor (20) and / or the second rotor (30) are formed in several parts, wherein a non-destructive separation between one of the circular base body (21, 31) and one of the associated vanes (25, 26, 35, 36) is provided.

8. rotary piston pump (10) according to claim 7, characterized in that the wings (25, 26, 35, 36) made of a softer material than the circular base body (21, 31) are made.

9. rotary piston pump (10) according to claim 7 or 8, characterized in that on at least one of the circular base body (21, 31) has a groove (28) for receiving one of the wings (25, 26, 35, 36) is formed.

10. rotary piston pump (10) according to any one of claims 7 to

9, characterized in that the wings (25, 26, 35, 36) as a hollow body (49) are formed, wherein the hollow body (49) are made in particular as deep-drawn parts or injection molded parts made of plastic.

11. rotary piston pump (10) according to one of claims 1 to

10, characterized in that the wings (25, 26, 35, 36) in the direction of rotation at least one trough (86), wherein the trough base (87) opposite the edge regions (82, 83) of the wing (25, 26, 35, 36) is set back.

12. rotary piston pump (10) according to one of claims 1 to

11, characterized in that the wings (25, 26, 35, 36) are formed axially symmetrical, wherein a point on the axis of symmetry (81) relative to the respective axially outer edge regions (82, 83) of the wing (25, 26, 35, 36) is set back.

13. rotary piston pump (10) according to claim 11 or 12, characterized in that the outer edge regions (82, 83) of the wing (25, 26, 35, 36) in the form of a curved line (84) are interconnected or an arrow shape (85 ) exhibit.

14. rotary piston pump (10) according to any one of claims 11 to

13, characterized in that the axis of symmetry (81) of the wing (25, 26, 35, 36) or the trough base (87) relative to the outer edge regions (82, 83) in the direction of rotation of the rotor (20, 30) by 5 ° to 30 ° rotation angle is set back.

15. Rotary piston pump (10) according to one of claims 11 to

14, characterized in that the housing (50) has a substantially elliptical basic shape, wherein the housing (50) at the main vertices (57, 58) of the ellipse

(56) each have a deviating from the substantially elliptical basic shape part circle shape, wherein the pitch circle section (59) extends over an angular range of more than 120 °.