EP1714035A1

EP1714035A1 - Rotary pump provided with an axially movable blade

Info

Publication number: EP1714035A1
Application number: EP04802974A
Authority: EP
Inventors: Manfred Sommer
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-01-09
Filing date: 2004-12-21
Publication date: 2006-10-25
Also published as: DE112004002786A5; EP1721078A1; US7614863B2; EP1714036B1; DE112004002792A5; WO2005066499A1; DE112004002789A5; EP1714036A1; WO2005066498A1; EP1714038A1; DE112004002788A5; DE112004002794A5; US20070148027A1; WO2005066500A1; DE112004002793A5; EP1714037A1; WO2005066497A1; WO2005066496A1; WO2005066501A1

Abstract

The invention relates to a pump (10) which is provided with a pump housing (12) comprising a cover (28), a rear wall (14) and an envelope wall (24) disposed therebetween. The collar (120) laterally describes a pump channel (124) provided with an input (152) and an output. The internal surface of the rear wall (14) is provided with a thin plate (15, 15.2) or a coating in such a way that medium pumped by the pump housing (12) does not contact said rear wall (14). The thin plate (15, 15.2) or the coating is made of material taking medium properties into account. The rear wall (14) is made of a rough material such as a cast material.

Description

_DRE H EN _PISTON _P UMPE WITH AXIAL MOVING WINGS

TECHNICAL AREA

The invention relates to a pump designed as a positive displacement pump or a rotary lobe pump. The main areas of application for pumps of this type which are viscous and viscous are found in the chemical, pharmaceutical and food processing industries.

STATE OF THE ART

From DE 34 18 708 AI a pump of the type mentioned is known. This pump has a rotor which is rotatably mounted on a drive shaft which can be connected to a motor drive. The rotor has a radially projecting, wave-shaped rotating rotor collar. The pump inlet and outlet are separate. The inlet communicates with an intake space and the outlet with an outlet space. These two pump rooms are connected to each other via a pump channel. By means of a sealing slide which is adjustable in the axial direction and which bears sealingly on both sides of the rotor collar in the axial direction, it is ensured that the medium conveyed from the inlet to the outlet by the pump channel cannot flow back past the sealing slide back to the inlet. The sealing slide must therefore continuously bear tightly on both sides of the rotor collar during the rotary movement of the rotor. Adequate sealing must also be present between the rotor collar and the walls of the pump channel that delimit it in the axial direction if the pumping action and thus the efficiency of the pump are not to be impaired. In this pump, the drive shaft driving the rotor extends far into the pump chamber. Their bearing points are located on the one hand in the area of the rear housing wall and on the other outside the pump housing in a hollow cylindrical shaft carrier flanged to the rear wall of the pump housing. The rotor is thus seated on the collar end area of the drive shaft. Due to the inevitable deflections of the collar end area of the drive shaft, the higher the higher the working pressures with which the pump is operated, correspondingly large tolerances between the rotating parts, such as the rotor collar, and the non-rotating parts, such as the channel walls framing the pump channel laterally, are taken into account in order to avoid undesirably high wear of parts rubbing against one another.

The area of application of the pump already mentioned at the beginning in hygienically sensitive areas makes it necessary that the components of the pump which come into contact with the medium being conveyed are harmless from a hygienic and pharmaceutical point of view. The material surfaces that come into contact with the medium conveyed through the pump must therefore take into account the properties of the respective medium. For this reason, the pump components that come into contact with the pumped medium, in particular the cover, the rear wall of the housing and the jacket wall of the pump housing, are not made from cast parts. The risk that voids are present in the castings, which can be sources of infection, is too great. As is known, therefore, rolled and forged steels in acid-resistant quality are used. The manufacture of the housing parts consequently requires a very high level of machining effort. This means that the weight of the housing can correspond to the weight of the material chips removed due to production. The dimensioning of the pump housing is determined by the structural requirements, such as the material thicknesses that are required for threads and through holes, which are used, for example, for screwing the cover and rear wall together. For reasons of strength, these wall thicknesses, particularly as far as the jacket wall is concerned, are regularly oversized.

PRESENTATION OF THE INVENTION

Based on this prior art, the invention has for its object to provide a pump to be operated of the type mentioned.

This invention is given by the features of the main claim. Useful further developments of the invention are the subject of further claims following the main claim. The pump according to the invention is characterized in that at least its rear wall, which for structural reasons is regularly very large, no longer comes into contact with the medium conveyed through the pump. The rear wall is covered by a thin plate or a coating towards the interior of the housing. The rear wall can thus consist of a raw material, such as, in particular, cast material. This brings considerable cost advantages for the manufacture of the pump according to the invention.

The casing wall of the housing, which in the prior art is regularly connected in one piece to the rear wall, can advantageously also consist of a thin wall that takes into account the properties of the pumped medium. This thin wall can be connected in one piece to the thin plate, which may be present on the inside of the rear wall. Such a pot-like housing consisting of a thin wall can then tightly enclose the interior of the housing from the rear and from the jacket side. An inexpensive material already mentioned above can then be used for the rear wall. The regularly existing oversizing, in particular of the jacket wall, then no longer needs to be carried out. The cost advantage over the prior art is very considerable. The pot-like housing can be manufactured, for example, as a deep-drawn part. In such a case, for better shaping of such a pump housing part, it makes sense to design the interior of the pump housing enclosed by the casing wall to widen conically towards the cover.

The rear wall of the pump housing can be releasably attached to a holding flange. The drive shaft, which is connected to the rotor in a rotationally fixed manner, then projects through this holding flange and the thin plate covering the inside of the rear wall and the rear wall.

Bearing points for the drive shaft can be formed in the holding flange or in the area of the rear wall and on the other hand in the interior of the pump housing.

A bearing point for the drive shaft can thus be present within the clearance area occupied by the rotor in the axial direction. The drive shaft no longer projects freely into the pump chamber, but is supported in the radial direction within the clearance area occupied by the rotor in the axial direction or preferably in the clearance area occupied by the rotor collar in the axial direction.

The extremely large deflections that have to be considered constructively in the prior art at correspondingly high working pressures no longer occur. This means that the bearing designs of the drive shaft and the design of the drive shaft itself no longer have to be dimensioned to such an extent that the deflections in the cantilever region of the drive shaft become correspondingly small. The bearing point for the drive shaft located within the pump housing has the further advantage that the overall length of the pump is considerably shorter compared to the previously known pump; the externally flanged-on hollow cylindrical shaft support according to the prior art, on the end of which is further away from the pump housing, a bearing point for the drive shaft can now be dispensed with. The drive shaft can be adequately supported in the area of the rear wall of the pump and within the clearance profile taken up by the rotor or its rotor collar in the axial direction.

The bearing point for the drive shaft inside the pump housing can be realized according to the exemplary embodiments also shown in the drawing by a hollow cylindrical shaft support which projects freely into the interior of the pump from the rear region. The shaft support can be designed to be sufficiently rigid so that the unavoidable deflections at its collar end are of no importance for the practical operation of the pump. For the rotor and its rotor collar, which is arranged in a rotationally fixed manner on the collar end region of the shaft carrier, it is therefore possible constructively to assume a bearing which is practically fixed in the axial direction. Such a pump not only builds much shorter than the pump known above in the prior art, but can also be operated with comparatively higher working pressures.

As already mentioned, the rotor collar must lie as close as possible to the fixed wall areas delimiting the pump channel in the axial direction in order to enable a correspondingly high efficiency of the pumps. Um now To prevent wear of the building walls and the rotor by rubbing against each other, it is known to line the pump channel with interchangeable wear parts, so-called stators. Existing deflections of the drive shaft, as are present in the prior art, make it necessary to maintain tolerances between the rotor and the stator which must be so large that the rotor does not touch the stator when the pump is under maximum load. To a certain extent, one helps by using plastic material for the stator, so that when it is touched by the rotor made of steel, there is no material removal from steel to steel. This problem is all the greater, the greater the deflection of the drive shaft. With these tolerances to be observed, it must also be taken into account in this connection that the different plastics expand to different extents under the influence of heat. Now such pumps are usually cleaned at temperatures that are 100 degrees Celsius and above, so that corresponding expansion tolerances of the respective plastics must be taken into account when designing the pump, so that it is ensured that the rotors are free even at high temperatures Pump room can rotate. The problem within the tolerances to be observed is decisively influenced by the existing deflections of the drive shaft and thus the rotor sitting on it; if the tolerances are too large, the efficiency of the pump drops sharply.

With the pump according to the invention, it is therefore no longer necessary to use more powerful pumps to avoid the above problems; Pumps that are not operated at full capacity have correspondingly smaller deflections, so that the tolerance problem is more favorable. Such larger pumps, which would not be required from the operational point of view, increase the operating costs of such a pump.

Due to the drive shaft forming a freely projecting structural part together with the shaft support, the rotor can encompass the drive shaft and also the shaft support at the end in the manner of an end cap. This then allows simple assembly and disassembly of the rotor, in that the rotor can be axially pushed onto the drive shaft in a rotationally fixed manner and can be held axially immovably on the drive shaft, for example by means of a retaining or locking nut. The bearing point of the drive shaft can be formed on the inside of the shaft carrier. An additional bearing point for the rotor can be formed on the opposite side of the shaft support, provided that the cap wall of the rotor is not sufficiently rigid that the rotationally fixed bearing point of the rotor on the drive shaft is sufficient.

According to an embodiment shown in the drawing, it is also possible to arrange the bearing for the drive shaft on the outside of the shaft carrier. This bearing point can then be used simultaneously as a bearing point acting in the axial direction for the rotor or for its cap area. In this case, the drive shaft attaches to the shaft carrier from the outside via the rotor.

The respective bearing point for the drive shaft and for the rotor, which is provided in the collar end region of the shaft carrier, if the latter is provided in addition to the rotationally fixed bearing of the rotor, can be arranged in the same axial cross-sectional plane.

In order to make bearings as slim as possible, each bearing point can consist of several bearings lying side by side in the axial direction.

In addition to this first bearing point described above, which is present within the pump housing, a second bearing point for the drive shaft can be present in the region of the rear wall of the pump adjacent to the motor drive. In the case of very light pump designs, this second bearing point could also be dispensed with and the drive shaft could only be mounted in the area of the motor drive.

It has proven to be advantageous to attach the pump housing to a bearing bracket in such a way that the pump housing can be attached to it in different rotational positions. In this way, the inlet and the outlet can be optimally spatially adapted to the corresponding local conditions even with a circular cylindrical outer contour of the pump housing. Such a bearing chair can have a holding flange to which the pump housing can be screwed, for example, in the desired rotational position. The drive shaft then penetrates this holding flange and ends in the pump housing. The second bearing point for the drive shaft, which is already available as an alternative, can then be provided in the holding flange.

As an alternative to this, this second bearing point could also be provided in the rear wall of the pump housing.

The shaft support projecting freely into the pump housing can be attached to the rear wall of the pump housing or also to the holding flange in a rigid manner. The shaft carrier, which in this case is not a part of the pump housing by weight, does not have to be taken into account by weight when the pump housing is removed from the holding flange.

The cover of the housing can have a circumferential, axial collar which bears tightly from the outside on the end region of the casing wall. This prevents the thin jacket wall from being deformed too easily by the pressures prevailing in the interior of the pump housing.

Further advantages and features of the invention can be found in the features further specified in the claims and in the exemplary embodiments below.

BRIEF DESCRIPTION OF THE DRAWING

The invention is described and explained in more detail below with reference to the exemplary embodiments shown in the drawing. Show it:

1 is a vertical longitudinal section through a first embodiment of a pump according to the invention,

Fig. 2 is a vertical longitudinal section through a second embodiment of a pump according to the invention.

WAYS OF CARRYING OUT THE INVENTION

The pump 10 shown in FIG. 1 is screwed to the rear flange 14 of its housing 12 by means of screws 16 on the holding flange 18 of a bearing block 20. The housing 12 is essentially rotationally symmetrical about its axis 22 formed, with the circular rear wall 14 in plan, and a circular cylindrical jacket wall 24. The rear wall 14 is lined on its inside with a thin plate 15. This thin plate 15 is connected to the jacket wall 24 in one piece. Instead of the thin plate 15, a coating can also be provided.

The left-hand end wall 26 of the casing wall 24 in FIG. 1 lies in an annular groove 25 of a cover 28 that closes the housing 12 in the axial direction. The cover 28 is provided with a plurality of stud bolts distributed circumferentially around the cover 28, of which only two in FIG the same are shown with their stud screw axis 30, screwed into the rear wall 14. The studs lead through the interior of the housing 12 and through the thin plate 15. Of the studs, the ring nut 34 screwed on the outside is shown in FIG. 1. Between the end face 26 of the jacket wall 24 and the cover 28, an O-ring 36 is inserted in the annular groove 25 encircling the cover 28, which ensures the required tightness. From the outside, the cover 28 encompasses - in FIG. 1 - the left end region 23 of the jacket wall 24 with a collar 29 which extends axially in the direction of the rear wall 14 and is integrally formed thereon.

The inner wall of the jacket wall 24 can be slightly conical in the shape of a circular cylinder or for the purpose of easier shaping when producing the one-piece piece consisting of the thin plate 15 and the jacket wall 24.

The thread sections present at the two ends of the stud screw are smaller in diameter than the diameter of the stud screw shaft present in the interior of the housing 12, so that each stud screw which screws the cover 28 and the rear wall 14 together fix the cover 28 and the rear wall 14 in a mutual manner Keeps distance from each other.

The bearing chair 20 has a footplate 38, which is connected to it at right angles in the present example and with which the housing 12 and thus the pump 10 can be placed on a base 40. This base 40 can also be a structural part which can be oriented as desired in space, because for example by means of a screw connection, of which two screw axes 42 are shown, the base plate 38 and thus the entire bearing bracket 20 can be releasably fixed to said base 40. A hollow cylindrical shaft support 50, the cylinder axis of which coincides with the axis 22, protrudes through the rear wall 14 and the thin plate 15 into the interior of the housing 12. The shaft support 50 is by means of an end flange 52 by means of a plurality of circumferentially distributed screws accessible from the outside 54 attached to the holding flange 18. The shaft carrier 50 is constructed in terms of material and cross section so that its collar end region ending in the housing 12 has practically no deflection under load, at least one deflection which is negligible for the operation of the pump 10.

A drive shaft 60 projects centrally through the shaft support 50. The right end of the drive shaft 60 in FIG. 1 can be connected in a rotationally fixed manner to the output shaft of a motor drive (not shown in the drawing) by means of a feather key 62, so that the drive shaft 60 in both directions of rotation is drivable.

A rotor 70 is fixed in a rotationally fixed manner to the collar end 64 of the drive shaft 60 which ends in the interior of the housing 12. The rotor 70 is - based on FIG. 1 - pushed from the left onto the collar end 64 of the drive shaft 60 and held in its fixed, rotationally fixed position by means of a lock nut 66 screwed onto the end of the drive shaft 60. The closure nut 66 lies sealed against the end wall 72 of the rotor 70 via an O-ring 68.

The rotor 70 has a rotor hub 74 which has a central recess pointing towards the rear wall 14, so that the rotor hub 74 in the form of a cap engages around the collar end region 76 of the drive shaft 60 from the outside at a distance. The collar end region 76 is adjoined in the direction of the projecting end of the drive shaft 60 by the collar end 64 and by this the screw region for the locking nut 66.

A tapered roller bearing 80 or inclined roller bearing is formed in the collar end region 76 between the drive shaft 60 and the shaft carrier 50. This tapered roller bearing 80 can absorb radial, in particular, also axial forces. Such forces acting on the rotor 70 can be transmitted or removed via its rotor hub 74 and via the drive shaft 60 to the shaft carrier 50 and ultimately to the bearing block 20. The tapered roller bearing 80 thus forms one in the interior of the housing 12 existing bearing point for the drive shaft 60, since the tapered roller bearing 80 is practically fixed in position in the housing 12 due to its support on the shaft support 50. The drive shaft 60 is thus held supported in the area of the tapered roller bearing 80.

The tapered roller bearing 80 is held on the left in FIG. 1 by a shoulder widening 82 of the drive shaft 60 and on the opposite right side by an axially supported bearing inner ring 84 seated in a shaft groove. Radially on the outside, the tapered roller bearing 80 is held in a fixed position between a support ring 86 screwed onto the end of the shaft support 50 and a recess 88 formed in the shaft support 50.

For the purpose of sealing, a shaft sealing ring 90 is arranged on the outside of the support ring 86, which sealingly rests on the shoulder widening 82.

On the outside of the shaft carrier 50 opposite the tapered roller bearing 80, a radial needle bearing 92 is arranged between the shaft carrier 50 and the rotor hub 74. The rotor hub 74 is also supported on the shaft carrier 50 via this needle bearing 92. This bearing 92 is - with reference to FIG. 1 - sealed on its left side by a shaft sealing ring 94, which is present between the rotor hub 74 and the shaft carrier 50. On its opposite side - based on FIG. 1 - on the right-hand side, a radial seal bearing 100 is connected to the radial needle bearing 92.

This sealing ring receptacle 100 lies against the inside of the rotor hub 74 in a rotationally fixed manner. The end face of the sealing ring receptacle 100, which has a rotationally symmetrical cross section, projects through the rear wall 14.

In the event of a leak, a sharp edge 104 facing away from the wall end area 102 ensures that the medium escaping from the shaft support 50 emerges from the area of the sealing ring receptacle 100. This leakage medium enters into an intermediate space 106 formed between the rear wall 14 and the holding flange 18, from which it is in the holding flange 18 trained, not shown in the drawing openings can come out.

A shaft sealing ring HO is supported on a radially projecting shoulder 108 of the sealing ring receptacle 100 and rests sealingly on the outside of the shaft carrier 50. Together with the shaft sealing ring 94, it seals the radial needle bearing 92 on both sides in the axial direction.

In the area of the holding flange 18 there is another bearing between the drive shaft 60 and the shaft carrier 50 in the form of a ball bearing 114. This ball bearing 114 is sealed off from the outside of the holding flange 18 by means of a shaft sealing ring 116, which in turn is held by a screw ring 118 screwed onto the holding flange 18 from the outside.

In the configuration shown in FIG. 1, the tapered roller bearings 80 and the radial needle bearing 92 are arranged in the same cross-sectional plane 112.

This cross-sectional plane 112 lies within the axial region of the rotor hub 74 and, moreover, also in the axial cross-sectional region of the rotor collar 120 integrally formed on the rotor hub 74.

This rotor collar 120 has a circumferential wave-like shape, as is described in detail in DE 34 18 708 A1 already mentioned above with respect to the prior art.

In the lower area of the housing 12 there is a pump channel 124, within which the rotor collar 120 moves back and forth in the axial direction when the drive shaft 60 rotates. The pump channel 124 is framed by a stator 130, which is composed of two stator halves 132, 134. In the present example, the two stator halves 132, 134 are identical in cross-section and lie closely together via a common contact surface 136. The two stator halves 132, 134 are kept pressed in between the cover 28 and the rear wall 14. The stud screws already mentioned above, which hold the cover 28 at a fixed position on the rear wall 14, also pass through the stator 130 or through its two stator halves 132, 134, outside the pump channel 124. The lid 28 has a central, annularly projecting lid area 138. A rotationally symmetrical front sleeve 140 is partially seated in the inner vault formed thereby. This front sleeve 140 is held screwed to the lid 28 or to its central lid area 138 via screws 142 accessible from the outside. The front sleeve 14O surrounds the end of the rotor hub 74 at a distance and the locking nut 66 screwed onto the drive shaft 60. In the present case, its inner wall 144 is curved, without sharp edges, so that it can be cleaned easily. The front sleeve 140 is sealed off from the cover 28 or the rotor hub 74 and the left stator half 132 by means of O-rings 146, 148 fitted all round in the front sleeve 140.

The top side of the front sleeve 140, based on FIG. 1, forms the bottom of the intake space or the outlet space 150, via which the pump channel 124 is connected on the one hand to the inlet 152 and on the other hand to the outlet of the pumps 10. The longitudinal axes 154 of the inlet 152 and the outlet are at right angles to one another in the present example.

A retaining ring 160 is positioned with its upper side in alignment with the upper side of the front sleeve 140 on the right side of the rotor hub 74 with reference to FIG. 1. With its upper side, this retaining ring 160, like the front sleeve 140, forms the bottom of the intake space or the outlet space 150.

The retaining ring 160 represents the sealing bottom area of the suction space or the outlet space 150 between the rotor hub 74 and the thin plate 15 of the housing 12. In the present example, between the rotor hub 74 and the retaining ring 160 are two axially and radially offset with the rotor hub 74 rotating seal rings 164, 166 fitted. Stationary sliding rings 165 and 167, respectively, press against these sliding rings 164, 166. These latter slide rings 165, 167 are pressed against the slide ring 164 and 166 by spring rings 168 and 170, respectively, which are supported on the rear on radially projecting shoulders 172 and 174 of the retaining ring 160.

The retaining ring 160 is fastened to the rear wall 14 by means of screws 176 arranged around the circumference. The slide rings 165, 167 can be made of any suitable material, such as, for example, in particular also of ceramic material. The rotating seal rings 164, 166 can in particular consist of metallic material.

The seals formed from the two sliding rings 164, 165 and 166, 167 can both be arranged in the axial direction in any mutual orientation.

The suction space and the outlet space 150 are separated from one another in terms of pressure by a slide guide 162, which represents a sealed shut-off plate between these two spaces. On the sliding guide 162, a sealing slide 182 bears back and forth in the axial direction. The sealing slide 182 is arranged in the outlet space 150, so that due to the pressure prevailing there, which is greater than the pressure prevailing in the suction space, it bears tightly against the slide guide 162 during its back and forth movement. In the sealing slide 182 there is a central opening 184 for the rotor collar 120 which is open at the bottom. During its rotating movement, the rotor collar 120 lies with its two collar walls on the side in the axial direction, of which one side wall 186 is visible in FIG. 1. This design principle is also described in detail in the aforementioned DE 34 18 708 AI.

The sealing slide 182 is held on its opposite side to the slide guide 162 by structural parts, not shown in the drawing, which are fixedly connected to the housing 12, so that the sealing slide 182, even when fallen compared to the illustration in FIG. 1, on the retaining flange 18 screwed rotary positions maintains its tight position on the slide guide 162 and does not fall away from the slide guide 162, for example in the circumferential direction. The slide guide 162 can be fixed in position, for example, by one of the stud bolts shown with its axis 30 between the cover 28 and the thin plate 15.

A plurality of leak drains 190 protrude from the rear wall 14 into the intermediate space 106 distributed over the circumference. These hose- or tube-shaped leak drains 190 connect the individual bearing spaces to one another via longitudinal and transverse bores, not shown in the drawing, formed in the shaft carrier 50, so that they are to be used for lubricating these bearings. The pump 10.2 shown in FIG. 2 is basically constructed like the pump 10 described above. Its rear wall 14.2 is also covered by a thin plate 15.2. The plate 15.2 forms with the casing wall 24.2 a one-piece, pot-shaped housing part produced as a deep-drawn part. A coating could again be provided instead of the plate 15.2.

The tapered roller bearing 80 and the radial needle bearing 92 lie in the same axial cross-sectional plane 112, which lies within the clearance area occupied by the rotor 120 in the axial direction. The additional bearing in the area of the holding flange 18.2, which in the present example also represents an auxiliary bearing for the drive shaft 60.2 designed as a ball bearing 114, is now provided with a retaining ring 118.2 which holds the shaft seal 116 axially instead of the screw ring 118 of the pump 10 and which is held by means of screws 117 is held screwed to the shaft support 50.2.

As further differences from the pump 10, the cover 28.2 of the pump 10.2 is flat on the outside and its rear wall 14.2 is designed without the cross-sectional reinforcement present in the lower region of the rear wall 14.

The retaining ring 160.2, which corresponds to the retaining ring 160, has a slightly different cross-sectional shape than the retaining ring 160 due to the different spatial conditions to the pump 10. Its function is the same as that of the retaining ring 160; Via two slide rings 165.2, 167.2, which are pushed away in the axial direction by spring rings, it bears sealingly against sealing rings 164.2 and 166.2, which are molded in the rotor hub 74.2.

The tapered roller bearing 80 is supported on its radial inside instead of the bearing inner ring 84 present in the pump 10 by a screw ring 84.2.

The intermediate space 106 is connected to the individual bearings via the leak drains 190 and transverse and longitudinal bores 196, 198, so that bearings can be provided with oil lubrication on the one hand, and corresponding media in the intermediate space 106 from leaks and from there not through in the drawing shown openings in the holding flange 18 or 18.2 can flow out of the pump 10 or 10.2.

Claims

Expectations

01. Pump (10, 10.2) - with a cover (28, 28.2), a rear wall (14, 14.2) and an intermediate wall (24) having a pump housing (12), - with a rotor (70) which is non-rotatable is present on a drive shaft (60, 60.2) which can be connected to a motor drive and which has a radially projecting, wave-shaped circumferential rotor collar (120), - with the rotor collars delimiting on both sides in the axial direction, a pump channel (124) between free-standing boundary surfaces, with an inlet (152) and an outlet for the pump channel (124), - with an adjustable in the axial direction, on the rotor collar (120) sealingly in the axial direction on both sides and the pump channel (124) between the inlet (152) and the Outlet dividing sealing slide (182), - characterized in that - a thin plate (15, 15.2) or a coating is present at least on the inside of the rear wall (14, 14.2) so that by the pump medium (12) pumped through does not come into contact with at least the rear wall (14, 14.2), - this thin plate (15, 15.2) or this coating consists of a material that takes into account the properties of this medium, - the rear wall (14, 14.2 ) from raw material, such as in particular from cast material.

02. Pump according to claim 1, - characterized in that - the jacket wall (24, 24.2) consists of a thin wall taking into account the properties of the pumped medium.

03. Pump according to claim 2, - characterized in that - the jacket wall (24, 24.2) is integrally connected to the thin plate (15, 15.2).

04. Pump according to claim 3, - characterized in that - the interior of the pump housing (12) enclosed by the casing wall (24, 24.2) widens conically towards the cover (28, 28.2).

05. Pump according to one of the preceding claims, - characterized in that - the rear wall (14, 14.2) is releasably attached to a holding flange (18, 18.2).

06. Pump according to claim 5, - characterized in that - the drive shaft (60, 60.2) penetrates the retaining flange (18, 18.2) and ends in the pump housing (12).

07. Pump according to claim 6, - characterized in that - a bearing for the drive shaft (60, 60.2) is present in the holding flange (18, 18.2).

08. Pump according to one of claims 5 to 7, - characterized in that - the pump housing (12) in different rotational positions on the holding flange (18, 18.2) can be fastened, such as in particular screwed.

09. Pump according to one of the preceding claims, - characterized in that - from the direction of the outer wall of the pump adjacent to the motor drive, a sleeve-shaped shaft carrier (50, 60.2) carrying the drive shaft (60, 60.2) is present, - in the collar region (76) of the shaft support, this first bearing point for the drive shaft is present, - the shaft support (50, 50.2), which carries the drive shaft (60, 60.2) for the rotor (70) and projects into the pump housing (12), on the retaining flange ( 18, 18.2) of the bearing bracket (20) can be fastened.

10. Pump according to one of the preceding claims, - characterized in that - the cover (28, 28.2) has a circumferential, axial collar (29), - this collar (29) from the outside at an end region of the jacket wall (24, 24.2) fits tightly.