DE202010012494U1 - Rotary pump and rotary piston - Google Patents

Abstract

Rotary lobe pump (10) for conveying fluids, in particular liquids loaded with solids, with a housing (45) and at least one pair of intermeshing rotary lobes (1) arranged within the housing (45), one rotary piston (1) each having at least one has a recess (13, 43) formed on its peripheral surface (5) and / or at least one recess (41) formed on an end surface (7, 9), characterized in that at least one driver (15, 17, 39, 51) in the at least one recess (13, 41, 43) is arranged and set up for detecting solid bodies.

Description

The present invention relates to a rotary lobe pump for conveying fluids, in particular liquids loaded with solids, having a housing and at least one pair of intermeshed rotary pistons arranged inside the housing, wherein a rotary piston each has at least one recess formed on its circumferential surface and / or at least one Having formed on an end surface recess.

The invention further relates to a rotary piston for a rotary piston pump for conveying fluids, in particular solids laden liquids.

Rotary lobe pumps of the aforementioned type are used for conveying any liquids, but in particular also for conveying sludge, sewage, dirty water, service water, thick matter, bilge water, faeces, liquid manure, chemicals or animal feed.

The known rotary lobe pumps are self-priming and dry running insensitive. The principle of operation is based on the fact that the rotary piston pump acting as a positive displacement pump causes the fluid transport by means of the at least two rotary pistons on one wall of the housing along the pump inlet to the pump outlet, while the at least two rotary pistons in the middle of the housing are fluid-tight against each other and rotate in opposite directions in a toothed manner.

In order to effect the fluid transport, cavities are formed between two adjacent piston tips and the housing wall, in which the fluid is guided along the housing wall from the pump inlet to the pump outlet. In order to ensure a reliable conveying function, the gap between a piston tip and the housing wall is designed to be as small as possible. However, this leads to an increased load on the surface of the piston tip or the housing wall, in particular in solids laden liquids. It occurs in the operation that solid wedged between the piston tip and the housing wall. Depending on the nature of the solid, this can cause damage to the surfaces. As a result, the tightness of the pump decreases, there is more reflux and the performance of the pump decreases. As a result, a maintenance of the pump, possibly with replacement of the housing wall or the piston is due.

In order to extend the service life of rotary lobe pumps and, consequently, their maintenance intervals, the approach has been followed, to provide recesses on the peripheral surface of the rotary lobe. This was done with the objective that the solids present in the fluid are forced into the recesses and consequently the wear of the piston surface or the surface of the housing inner wall can be contained. Such a rotary pump with a corresponding rotary piston shows, for example, the document WO 2007/026109 , A rotary pump in which the rotary pistons have a plurality of grooves, is also in publication DE 42 18 855 A1 proposed.

However, it has been shown that the known devices only to an unsatisfactory extent have a positive influence on the wear behavior.

Consequently, the present invention has the object to provide a rotary piston pump and a rotary piston, which have an increased wear resistance.

The invention solves the underlying object in a rotary piston pump of the type mentioned by at least one driver is arranged in the at least one recess and adapted to detect solids. It has been found that the accumulation of solids in the recesses of the rotary piston is significantly improved when a driver is inserted into the recess. Thus, although the available volume in the recess of the rotary piston decreases, the driver positively contributes to detect larger amounts of solids and to direct into the recess. In this case, the solids are at least partially pressed by nachrückenden solids in the recess.

As a result of the constant detection of solids by means of the driver, an ever greater amount of solid material is successively accumulated in the recess. It comes to a compression of the solid-state material. Consequently, in the medium term, the gap between the peripheral surface of the rotary piston and the housing wall is sealed by the compacted solid state material. As a result, although an increased rotational resistance for the drive of the rotary pistons must be taken into account, but the return flow rate decreases.

The driver is preferably made of a wear-resistant material, so that the driver also has a certain resistance against penetrating solids, which in turn have a high strength. Particularly preferably, the driver is made of hardened steel. Damage to the driver as a result of such solid is associated with significantly less effort in the maintenance as damage to the Rotary piston or the housing wall. The driver according to the invention is preferably arranged interchangeable in the recess.

In a preferred embodiment of the invention, a gap is formed between a boundary of the at least one recess and the at least one driver. The gap is thus defined on the one hand by the type of boundary and on the other hand by the shape of the driver. The smaller the driver compared to the size of the recess, the greater will usually be the distance between the driver and the boundary at least in a part-section of the boundary. The gap is advantageously configured to receive solids captured by the driver. From the point at which reach the detected by the driver solids in the gap, they are preferably pressed by subsequent solids in the depth of the recess.

In a further preferred embodiment of the invention, the gap has wedge-shaped widened sections. It has been found to be particularly advantageous not to uniformly shape the gap along its entire length. Portions in which the gap widened in the manner of a wedge shape increase the amount of solids captured by the driver. Preferably, the wedge-shaped widened portion is arranged between the driver and the boundary of the recess, that in the direction of rotation of the rotary piston of the rotary piston pump solids first pass into a wide portion of the wedge-shaped portion to then be driven between the ever more tapered flanks of the wedge-shaped portion.

Preferably, the at least one recess is formed as a groove and has a cross-section which is substantially rectangular and / or at least partially conically tapered towards the bottom of the recess, or at least partially conically widened towards the bottom of the recess. A rectangular configuration of the cross section of the recess can be realized time-consuming and cost-effective from production-technical aspects. A design of the side surfaces of the recess that tapers towards the bottom of the recess favors the penetration of solids into the depth of the recess, while a conically widened course of the side surfaces of the recess towards the bottom of the recess makes it more difficult for solids to escape from the recess. However, the cleanability is hampered by an extended to the bottom of the recess towards conical shape. An optimum embodiment of the recess results in the interaction of the recess with the driver inserted into the recess and may vary from case to case. Also, different geometries are to be provided depending on the medium to be primarily conveyed.

The at least one driver is formed according to a first preferred alternative as a flat body, wherein the height of the flat body is less than or equal to the depth of the at least one driver receiving recess. Characterized in that the flat body has a lower height than it does the receiving recess, it can be prevented that the flat body itself comes in frictional contact with the housing wall and thus damage it. At the same time, this ensures that solids also settle above the driver even in compacted form. As a result, the driver itself is protected against further wear. Achieved a rotary piston in the rotary lobe pump this condition, however, is also the disadvantage to be taken into account that its actual function, namely to provide more solid in the recess, can no longer be perceived by the driver.

The first preferred alternative is advantageously further developed in that one or more wedge-shaped recesses are provided on at least one side surface of the at least one driver, which faces the boundary of the recess. The wedge-shaped recesses at least partially define a wedge-shaped widened portion between the boundary of the recess and the driver. The driver preferably has an optimized for the individual main application of the rotary piston pump distribution, arrangement and shaping of the wedge-shaped recesses. The wedge-shaped recesses preferably extend both in the radial and in the tangential direction (with the driver inserted into the rotary piston). This embodiment supports the displacement of solids in the depth of the recess by nachrückende solids.

According to a further preferred embodiment, the at least one driver has adjacently arranged projections, between each of which a gap is formed. The preferably formed as a flat body driver with the plurality of protrusions preferably works in a similar manner as a comb. The projections, which may be cylindrical or polygonal, preferably extend from the bottom of the recess towards the surface of the piston and define wedge-shaped widened portions each extending between the edge of a recess and two adjacent projections.

According to a preferred second alternative of the present invention, the at least one driver is designed as a dowel pin, threaded pin or cap screw. Preferably, a plurality of drivers are adjacent and reversibly releasably secured in the at least one recess. Particularly preferably, a gap is formed between adjacent carriers. Further particularly preferably defined as a dowel pin, threaded pin or screw driver between them and the boundary of the recess wedge-shaped widened sections of the gap between the boundary of the recess and the drivers. As an alternative to the above-mentioned elements, the drivers are designed as elements having a cylindrical, elliptical, or polygonal cross section, which can be arranged and fastened separately in the recess. Preferably, these elements are arranged so that solid bodies are detected and accumulated between adjacent elements.

The embodiment of the invention with a plurality of drivers per recess, for example as a dowel pin, threaded pin or cap screw, or other elements explained above, is particularly preferred for use on the peripheral surface of obliquely extending, also referred to as helical piston rotary piston. The possibility of positioning the individual carriers in the recess in a position-fitting and precise manner brings with it clear manufacturing advantages over individually manufactured flat bodies, precisely because the latter have to be formed exactly on the course of the coiled circumferential surface of the piston.

Preferably, the one or more drivers designed as cap screws, which are fastened in the one or more exceptions, have no expansion section, and / or are each screwed into a threaded bore, the thread of which extends in the screwed state up to a head bearing surface of the screw. In this way, the clamping length of the screw connection is minimized. The applied tension is effected to the smallest possible proportion by means of the longitudinal expansion of the screw. This implies, conversely, that the screws by turning a few degrees already solvable. The loosening can be effected advantageously by means of loose-fitting, if the screw heads no longer allow a key engagement, for example due to damage or contamination.

According to a preferred third alternative, the at least one driver is designed as a helical spring, which is arranged at least for the most part within the recess, wherein the longitudinal axis of the helical spring is arranged parallel to the base of the recess. Between the individual turns of the coil spring many solids are detected in an advantageous manner. The turns of the coil spring are aligned by the horizontal arrangement of the coil spring in the recess so that the detected solids are guided along the turns in the interior of the recess. The helical spring is preferably elastically deformable in the radial direction in addition to elasticity in the longitudinal direction of the helical spring. In this way, the coil spring may extend partially outside the recess. Characterized in that the coil spring is largely disposed within the recess and extends only with a smaller part outside the recess, the coil spring is elastically deformed upon impact of the coil spring in a tangential manner on the housing wall and displaced into the interior of the recess.

According to a further preferred alternative embodiment of the invention, the rotary pistons on a wing each have a sealing line along which the rotary pistons occupy a minimum distance to an inner wall of the housing of the rotary piston pump. Several recesses are adjacent in the peripheral surface, preferably arranged parallel to the sealing line, wherein as a driver preferably elastically deformable sealing body are provided which extend partially outside the recess in the direction of the housing wall. Analogous to the coil springs discussed above, the carriers formed as elastically deformable sealing bodies also take up or contact a minimal distance from the housing inner wall. In this way, each further sealing lines are formed by means of the elastically deformable sealing body.

The elastically deformable sealing bodies are preferably designed to be displaced in contact with the oppositely arranged other rotary piston into the interior of the recess and to return to the original position after the displacement. Moreover, the elastically deformable sealing bodies are also preferably arranged to retreat in front of solids acting on them, so that the solids pass past the displaced sealing bodies into the depth of the recess by being pressed in by subsequent solids. The embodiment with trained as elastic sealing bodies drivers also offers the advantage that in an arrangement of the sealing body receiving recesses immediately adjacent the sealing line additional sealing lines are provided, provided that the distance of the piston surface of the housing inner wall at the location of the recess with the elastic sealing bodies is not greater than the amount to which the sealing body extend outside of the receiving recess.

The invention solves its underlying object in a rotary piston of the type mentioned above with at least one recess formed on its peripheral surface and / or at least one recess formed on its end face by arranged at least one driver in the at least one recess and set up for detecting solids is. With regard to further advantageous embodiments of the rotary piston according to the invention, reference is made to the above comments on the rotary piston pump.

The invention further relates to a method for sealing a rotary piston against an inner wall of the housing of a rotary piston pump, comprising the steps:
Conveying a fluid, in particular a liquid loaded with solids by means of a rotary piston pump, and detecting solids from the delivered fluid by means of one or more drivers which are arranged in one or more recesses of the rotary piston. With regard to the advantages of the method according to the invention and with regard to advantageous developments, reference is made to the above explanations to the rotary piston pump and to the rotary piston.

In the following, the present invention will be explained in more detail with reference to preferred embodiments with reference to the attached drawings. This shows

1 a spatial representation of a rotary piston according to the invention for the rotary piston pump according to the invention;

2 a cross-sectional view through a driver for the rotary piston according to the invention;

3a a spatial representation of an alternative driver for the rotary piston according to the invention;

3b a spatial representation of another alternative driver for the rotary piston according to the invention;

4 a spatial representation of another alternative of a driver for the rotary piston according to the invention;

5 a sectional view of a detail of the rotary piston according to the invention in a preferred embodiment;

6 a sectional view of an alternative embodiment of the rotary piston according to the invention;

7 a sectional view of a detail of another alternative of the rotary piston according to the invention;

8th a sectional view of a detail of another alternative embodiment of the rotary piston according to the invention;

9 a spatial view of a rotary piston according to another preferred embodiment of the present invention;

10 a spatial representation of another preferred embodiment of the rotary piston according to the invention;

11 Yet another embodiment of a rotary piston according to the invention;

12 a partial view of a rotary piston pump according to the invention;

13 a sectional view through the rotary piston pump 12 ; and

14 a detailed view of the presentation 12 ,

In 1 a rotary piston according to the invention is shown according to a first preferred embodiment. The rotary piston 1 has three slanted wings, each with a peak section 3 exhibit. The rotary piston 1 has a peripheral surface 5 , an upper face 7 and a lower end surface 9 on. A recess 11 extends from the upper end side 7 to the lower end 9 and is adapted to receive a drive shaft. Along the circumference of the rotary piston 1 are in every top section 3 the wing respectively recesses 13 intended.

In 1 are exemplary illustrated two alternative embodiments of the rotary piston according to the invention. In the in 1 left recess shown 13 is a flat body 15 trained driver arranged. Between the flat body 15 and a boundary of the recess 13 is a substantially uniformly formed gap 19 educated.

In 1 right is a recess 13 shown in which a variety as screws 17 trained driver are used. The screws 17 are with a minimum clamping length in each case a thread in the bottom of the recess 13 screwed. Due to the minimal Clamping length are the screws 17 even with damage and strong deformations of the key engagement still solvable. Between the as screws 17 trained drivers and the boundary of the recess 13 in 1 on the right a gap is formed, which, however, is not uniform. Between each adjacent screws 17 and the boundary of the recess 13 Wedge-shaped widened sections are formed. The wedge-shaped extended sections 21 are adapted to hold solid, which were detected by the drivers, and record in the recess.

In the 2 to 4 are different embodiments of drivers for the rotary piston according to the invention 1 shown. In 2 is a cross section of a flat body 15 trained driver represented. The viewing direction corresponds to an inserted driver substantially a radial direction with respect to the axis of rotation of the rotary piston. The flat body 15 has a basic body 23 on. In the opposite side surfaces of the body 23 are each a plurality of wedge-shaped recesses 25 brought in. The wedge-shaped recesses 25 are designed to wedge solids.

In 3a is a spatial representation of a flat body 15 trained driver according to an alternative embodiment. The in 3a shown driver has as well as in 2 shown driver a body 23 on. The main body 23 out 3a has a substantially trapezoidal cross-section. Two opposite side surfaces 26 are aligned conically to each other. A top 27 , which faces the housing wall when the driver is inserted, is wider than a bottom 29 the driver, which faces in the inserted state to the bottom of him receiving recess. In the side surfaces of the main body 23 of the flat body 15 are several wedge-shaped recesses 25 brought in. The wedge-shaped recesses are offset from each other to ensure a maximized size of the wedge-shaped recess. The flat body 15 according to 3a is as well as the flat body according to 4 designed to along an axis 30 be fastened by means (not shown) fastening means in the recess.

The in 3b shown driver differs from the in 3a shown drivers that the side surfaces 26 of the basic body 23 into which the wedge-shaped recesses 25 offset from each other, are aligned parallel to each other, which is alternatively achieved by a rectangular cross-section or a parallelogram-shaped cross section of the body. Furthermore, in 3b two on the top 27 arranged countersunk holes 28 shown for receiving a corresponding screw head. The in 3b shown piston is for use in the peripheral surface of a rotary piston such as according to 1 or 9 optimized. It is wound along its longitudinal direction, in order to ensure optimum adaptation to the likewise wound recess in the peripheral surface of such a rotary piston.

In 4 is a further embodiment of a driver shown, as a flat body 15 is trained. The flat body 15 out 4 has a basic body 23 on which of which is on the top 27 of the main body starting several projections 31 extend. The projections 31 are arranged substantially parallel to each other and extend in the direction of the housing wall of the rotary piston pump when the rotary piston is inserted. The projections 31 can optionally be arranged at an angle to each other to V-shaped or A-shaped column 33 between adjacent protrusions 31 form, which is advantageous for the detection of solids. For attachment of the flat body 15 trained driver according to 4 is advantageous a lead 31 formed as part of a screw, which along the axis 30 through the main body 23 is screwed through into the bottom of the recess for the driver.

The 5 to 8th show various advantageous embodiments of the driver receiving recesses. In 5 is a recess 13 shown with a substantially rectangular cross-section. The recess 13 is optional in the peripheral area 5 , or one of the faces 7 . 9 provided and has two substantially parallel side surfaces 35 on. The depth of the recess 13 in the rotary piston 1 is slightly larger than the height of the driver to be received in the recess 15 or 17 , If the driver 15 . 17 at maximum depth in the recess 13 is arranged, lies the driver 15 . 17 preferably with a bottom at the bottom 37 the recess 13 at. In the 5 to 8th is each a gap 19 shown between the boundary of the recess 13 and the driver 15 . 17 is trained.

In 6 is different from 5 a recess 13 shown, which does not have a completely rectangular cross-section. Instead, the cross section of the recess 13 according to 6 only partially rectangular. From the area 5 . 7 . 9 starting from the cross section of the recess runs 13 initially conically tapered to the bottom 37 the recess and then assumes a rectangular shape.

The in 7 illustrated cross section of the recess 13 is from the area 5 . 7 . 9 From the perspective of, initially formed essentially conically widened and only then in the direction of the ground 37 the recess formed rectangular. In comparison, the cross section of the recess 13 according to 8th essentially completely to the bottom of the recess 37 formed conically widened.

The in the 7 and 8th shown cross sections are particularly preferred for drivers with a substantially cylindrical cross-sectional profile, such as elastically deformable sealing bodies 39 or lying coil springs 51 (S. 14 ). However, it should be noted that even as a flat body 15 or screws 17 trained drivers in recesses 13 according to the 7 or 8th or further, appropriately trained geometries can be arranged.

After the in 1 Rotary pistons shown exclusively on the peripheral surface arranged recesses for receiving carriers are in the 9 to 11 further preferred embodiments of the rotary piston according to the invention 1 shown with further preferred arrangements of the recesses.

So shows 9 a three-winged rotary piston 1 with three top sections 3 on each wing and one else too 1 comparable interpretation. In contrast to the rotary piston according to 1 are however with the rotary piston 1 according to 9 in addition to the circumferentially arranged recesses 13 with carriers 17 also on the front page 7 (and optionally also on the lower front side 9 ) on each wing recesses 41 arranged. In the recesses 41 are analogous to the recesses 13 on the peripheral surface 5 Driver can be arranged as a screw 17 or as a flat body 15 or are designed as further driver according to the invention. In the 9 shown recesses 41 are substantially radially on the axis of the recess 11 arranged tapered. Optional are the recesses 41 preferably to be arranged outside the radial line, and / or at an angle to the radial line.

In 10 is a double-lobed rotary piston 1 represented, which at the two wings in each case a tip section 3 having. The two-winged rotary piston 1 according to 10 has straight wings. In the top sections 3 is in each case in the region of the sealing line a recess 13 arranged in the peripheral surface 5 from below the upper end face 7 until just above the lower end face 9 extends. On the front page 7 of the rotary piston 1 according to 10 are recesses on each wing 41 arranged. The recesses 41 wise as well as the recesses 13 a longitudinal axis (not shown). In the 10 embodiment shown provides that the axes of the recesses 13 and 41 does not intersect - considered for a respective wing. In this way it is possible the length of the recesses 13 . 41 to bring to the edge of the respective surface, without the recesses 13 . 41 collide with each other. Regarding the inclusion of drivers in the recesses 13 . 41 is referred to the above to the 1 to 9 directed.

In 11 is another embodiment of a rotary piston according to the invention 1 shown. The rotary piston 1 according to 11 is also a double-lobed piston with a straight piston. The rotary piston 1 according to 11 again has peak sections 3 on the piston wings, a peripheral surface 5 , as well as an upper and a lower end face 7 . 9 , In contrast to the rotary piston off 10 are in the frontal area 7 however, on each wing of the rotary piston 1 two recesses 41 arranged in a substantially radial orientation. The recesses 41 on the face 7 are each executed in a single row, whereas on the peripheral surface 5 of the piston 1 according to 11 at each wing in the region of the sealing line a multi-row recess 43 is provided. In the recess 43 are according to 11 two rows of as screws 17 arranged trained drivers. The screws 17 are side by side and laterally offset from each other within the multi-row recess 43 arranged, reducing the number between the screws 17 trained column and in particular their suitability to capture and tighten solids is improved.

In 12 is a part of a rotary piston pump according to the invention 10 shown. The rotary lobe pump 10 has a rotary piston according to the invention 1 on, which is rotatably disposed within a housing. The housing has a semi-cylindrical section 45 on. Within the section 45 is an interior wall 47 concentric with the rotary piston 1 educated. Between the rotary piston 1 and the housing inner wall 47 be during rotation of the rotary piston 1 Cavities formed within which fluid is transported from a pump inlet to a pump outlet. A cavity is defined by the area of the inner wall 47 on the one hand and on the peripheral surface 5 of the rotary piston 1 on the other hand limited. To prevent fluid leakage from one cavity to the other, is the distance of the rotary piston 1 the housing section 45 keep as minimal as possible. In a sealing section 49 is preferably formed a sealing function.

After fluid leakage also over the front page 7 of the piston 1 can occur between the cavities, is preferably also on the front side 7 to provide a sealing function.

Front side, the sealing function is in a particularly preferred embodiment by the driver 39 . 51 guaranteed. This is in 13 shown, which is a sectional view through the piston 12 represents. In the front side 7 and the front side 9 each is a recess 41 intended. In the in 13 illustrated lower recess 41 is a driver used. The driver has a substantially cylindrical cross-section. Either the driver is an elastically deformable sealing body 39 , or as a coil spring 51 educated. The elastically deformable sealing body 39 allows a better seal, whereas the as a coil spring 51 trained driver has a higher capacity for detecting solids.

A detail section 12 is in 14 shown enlarged. The sealing section 49 of the rotary piston 1 has a first sealing line 53 on. The clear width between the peripheral surface 5 of the rotary piston 1 and the inner surface 47 the housing section 45 is along the sealing line 53 minimal, ideally approximately equal to 0. Right and left of the sealing line 53 stand two carriers, each within a recess 13 are arranged along a line 55 also with the inner wall 47 the housing section 45 contact or take to the inner wall 47 a minimum distance. This is the lines 55 also designed as sealing lines. The sealing lines are substantially parallel to the first sealing line 53 aligned. The tightness and thus the efficiency of the rotary piston 1 the rotary lobe pump 10 becomes by means of the additional sealing lines 55 improved.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2007/026109 [0006]
• DE 4218855 A1 [0006]

Claims (12)

Rotary piston pump ( 10 ) for conveying fluids, in particular solids laden liquids, with a housing ( 45 ) and at least one pair interlocked, within the housing ( 45 ) arranged rotary piston ( 1 ), whereby a rotary piston ( 1 ) at least one on its peripheral surface ( 5 ) formed recess ( 13 . 43 ) and / or at least one on an end face ( 7 . 9 ) formed recess ( 41 ), characterized in that at least one driver ( 15 . 17 . 39 . 51 ) in the at least one recess ( 13 . 41 . 43 ) and arranged to detect solids. Rotary piston pump ( 10 ) according to claim 1, characterized in that between a boundary of the at least one recess ( 13 . 41 . 43 ) and the at least one driver ( 15 . 17 . 39 . 51 ) A gap ( 19 ) is trained. Rotary piston pump ( 10 ) according to claim 1 or 2, characterized in that the gap ( 19 ) wedge-shaped extended sections ( 21 ) having. Rotary piston pump ( 10 ) according to one of the preceding claims, characterized in that the at least one recess ( 13 . 41 . 43 ) is formed as a groove and has a cross section which - at least partially conically tapers toward the bottom of the recess - substantially rectangular and / or - to the bottom of the recess, or - at least partially conically widened towards the bottom of the recess. Rotary piston pump ( 10 ) according to one of the preceding claims, characterized in that the at least one driver as a flat body ( 15 ), wherein the height of the flat body ( 15 ) is less than or equal to the depth of the at least one driver receiving recess ( 13 . 41 . 43 ). Rotary piston pump ( 10 ) according to claim 5, characterized in that on at least one side surface ( 26 ) of the at least one driver, which of the boundary of the recess ( 13 . 41 . 43 ), one or more wedge-shaped recesses ( 25 ) are provided. Rotary piston pump ( 10 ) according to claim 5 or 6, characterized in that the at least one driver a plurality of adjacently arranged projections ( 31 ), between each of which a gap ( 33 ) is trained. Rotary piston pump ( 10 ) according to one of claims 1 to 4, characterized in that the at least one driver as dowel pin, threaded pin or cap screw ( 17 ), wherein preferably a plurality of drivers adjacent and reversibly detachable in the at least one recess ( 13 . 41 . 43 ) Are attached, and wherein between adjacent carriers each have a gap is formed. Rotary piston pump according to one of claims 1 to 4, characterized in that the at least one driver as a helical spring ( 51 ) is formed, which at least largely within the recess ( 13 . 41 . 43 ) is arranged, wherein the longitudinal axis of the coil spring ( 51 ) parallel to the bottom of the recess ( 13 . 41 . 43 ) is arranged. Rotary piston pump ( 10 ) according to one of claims 1 to 4, wherein the rotary pistons ( 1 ) at one wing in each case a sealing line ( 53 ) along which the rotary pistons ( 1 ) a minimum distance to an inner wall ( 47 ) of the housing ( 45 ), and several recesses ( 13 ) in the peripheral surface adjacent, preferably parallel, to the sealing line ( 53 ) are arranged, are characterized in that as a driver elastically deformable sealing body ( 39 ) are provided, which partially outside the recess ( 13 ) in the direction of the inner wall ( 47 ) of the housing ( 45 ). Rotary piston pump ( 10 ) according to one of claims 8 to 10, characterized in that one or more than cap screws ( 17 ) trained drivers in the at least one recess ( 13 . 41 . 43 ), the head screws ( 17 ) preferably have no Dehnabschnitt, and / or are respectively screwed into a threaded bore, the thread extends in the screwed state up to a head support surface of the cap screw. Rotary piston ( 1 ) for a rotary lobe pump ( 10 ) for conveying fluids, in particular solids laden liquids, with at least one on its peripheral surface ( 5 ) formed recess ( 13 . 43 ) and / or at least one on an end face ( 7 . 9 ) formed recess ( 41 ), characterized in that at least one driver ( 15 . 17 . 39 . 51 ) in the at least one recess ( 13 . 41 . 43 ) and arranged to detect solids.

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