EP3224478B1 - Rotary piston pump, method for securing rotary pistons of a rotary piston pump and method for removing rotary pistons of a rotary piston pump - Google Patents

Description

The present invention relates to a rotary piston pump, a method for fixing rotary piston of an aforementioned rotary piston pump or method for disassembling rotary piston of an aforementioned rotary piston pump according to the features of the preamble of claims 1, 7 and 15.

State of the art

The present application relates to the fixation of rotary piston of a rotary piston pump on the respective drive shaft.

Rotary lobe pumps are self-priming or conditionally self-priming, valveless, positive positive displacement pumps with rotating lobes. In particular, rotary lobe pumps comprise at least two oppositely revolving two- or multi-leaf rotary pistons whose drive shafts comprise seals. Preferably, rotary lobe pumps have two drive shafts for two rotary lobes.

According to the DE 19806657 the drive shafts are provided at their arranged in the pump room end with screw for attaching the rotary piston. The drive shafts are each formed in one piece and remain during assembly or disassembly of the rotary piston in the pump housing. It is provided that one of the drive shafts is connected via a coupling to the drive and in the uncoupled state is freely rotatable relative to the other drive shaft.

DE 102012003066 B3 describes a method and apparatus for fixing and synchronizing rotary pistons of a rotary lobe pump. Here, the rotary pistons are introduced in the pump room. A stub shaft of each rotary piston is pushed by the pump rear wall on the respective drive shaft. The rotors are aligned with a template in the pump room and synchronized. The template is releasably fixed to the pump housing in this alignment step. The stub shafts of the aligned rotary pistons are each by means of a Clamping device frictionally connected to the respective drive shaft outside the pump room.

DE 102013101185 A1 discloses a rotary pump, wherein the seals are arranged on a shaft extension of the respective rotary piston and a sliding ring per seal is provided with a locking device having a plurality of fixing positions. The seal with the locking device is placed on the tubular shaft extension and the shaft extension of each rotary piston is pushed by the pump rear wall to the respective drive shaft. By turning the rotary piston, a securing element is positively placed in axial grooves of the locking device in connection. Subsequently, the shaft extension and thus the rotary piston is non-positively connected via a clamping device with the respective drive shaft outside the pump chamber.

EP 0577064 A1 describes a rotary pump for conveying liquid food. The two rotary pistons each have a receptacle for the respective drive shaft. The end region of the respective drive shaft is arranged and fixed in the receptacle of the respective rotary piston.

JP S61 149615 A discloses the attachment of a rotating body to a rotating shaft. Here, special processing on the rotating body is necessary. There is formed a female threaded portion and a tapered hole continued at an end portion of the rotary shaft, and a fastener screw having a male threaded portion and a tapered portion therein can be screwed / fitted therein.

The document DE 10 2009 029296 A1 describes a press connection of a shaft with a drive element or driven element pressed thereon. The shaft has at least partially an axially extending recess, through which it is formed in this area as a hollow shaft. The aim of the invention is to divide the strains and resulting deformations more uniformly between the shaft and the drive or driven element pressed thereon.

The object of the invention is to easily and quickly fix the rotary pistons of a rotary pump to the respective drive shaft, so that torques and axial forces are transmitted without play from the drive shaft in the rotary piston.

The above object is achieved by a rotary pump, a method for fixing rotary piston of an aforementioned rotary piston pump or a method for disassembly of rotary piston of an aforementioned rotary piston pump, comprising the features in the claims 1, 7 and 15. Further advantageous embodiments are described by the subclaims.

description

The invention relates to a rotary lobe pump with at least two arranged in a pump space to drive shafts, in opposite directions revolving rotary piston. There is always a contact between the rotary pistons and a pump housing surrounding the pump chamber, wherein pump chambers are formed between the rotary pistons and the pump housing. The product to be pumped is drawn in through the pump chambers, conveyed by the rotary lobe pump and ejected on the opposite side of the pump.

According to the invention, a diameter of the drive shafts can be elastically expanded in the end region. In an operating state in which the rotary pistons are arranged non-rotatably on the respective drive shafts, there is a frictional connection between the respective receiver formed of the rotary piston and the end portion of the respective drive shaft. As a result, a backlash-free power transmission can take place. In a changing state in which, for example, maintenance work on the rotary lobe pump is carried out and for the rotary lobe must be removed from the drive shafts, this frictional engagement is, however, canceled. According to another embodiment, in the operating state in which the rotary pistons are arranged rotationally fixed on the respective drive shafts, a frictional and positive connection between the respective receptacle of the rotary piston and the end region of the respective drive shaft is formed. In a changing state, in which, for example, maintenance work on the rotary lobe pump is carried out and for the rotary lobe must be removed from the drive shafts, this frictional and form-fitting is, however, canceled.

The fixing of rotary pistons to drive shafts of an aforementioned rotary pump takes place in the following method steps: The rotary pistons are pushed onto the respective drive shafts, so that the end region of the respective drive shafts is arranged in the receptacle of the respective rotary piston. At this time, a game is formed between the drive shaft and the receptacle, so that the rotary pistons can be arbitrarily aligned with the respective drive shafts. According to one embodiment of the invention, the alignment of the pushed onto the drive shafts rotary piston takes place at the same time by means of a template, analogous to that in the DE 102012003066 described prior art.

Subsequently, the end portions of the drive shafts are respectively expanded, so that a frictional engagement between the receptacle of the rotary piston and the end portion of the drive shaft is produced. As a result, the rotationally fixed fixing of the rotary piston takes place on the drive shafts.

For disassembly, for example, in the context of maintenance work on the rotary pump or the like, the frictional engagement between the receptacle of the rotary piston and the end portion of the drive shaft is canceled or released by reducing a diameter of the end portion of the drive shaft, so that the rotary piston can be easily removed from the drive shafts ,

According to a preferred embodiment of the invention the end portion of the drive shaft and / or the receptacle of the rotary piston is associated with a clamping and / or clamping device for fixing the rotary piston by means of frictional engagement on the respective drive shaft. In the context of the present invention is by the Adjusting the clamping and / or clamping device of the rotary piston so fixed to the respective drive shaft, that torques and axial forces are transmitted without play from the drive shaft in the rotary piston. By loosening the clamping and / or clamping device, this operative connection is canceled, so that no transmission of the torques and axial forces from the drive shaft into the rotary piston takes place.

The clamping of the rotary piston with the drive shaft can be done in various ways. It can, for example, mechanical elements are used in the drive shaft or hydraulic and / or pneumatic elements are installed.

For example, according to one embodiment of the invention, the clamping and / or clamping device comprises size-variable hydraulic and / or pneumatic elements. By introducing a suitable hydraulic fluid and / or a suitable gas into the clamping and / or clamping device, and by pressurizing the fluid used, the outer diameter of the drive shaft is expanded in the end region arranged in the pump chamber within the receptacle. Accordingly, by removing the pressure from the fluid, that is from the hydraulic fluid and / or the gas from the clamping and / or clamping device of a fixed drive shaft rotary piston arrangement, the outer diameter of the end portion of the drive shaft is reduced, so that he now again Output outer diameter along the longitudinal axis of the drive shaft corresponds and thus again a game between the end portion of the drive shaft and the receptacle of the rotary piston is formed.

According to a further embodiment of the invention, the clamping and / or clamping device comprises as mechanical elements so-called cone elements. By moving the cone elements in a first direction of movement in the region of the receptacle of the rotary piston and / or by moving the cone elements within the arranged in the pump chamber within the receptacle of the rotary piston end portion of the drive shaft, the outer diameter of the end portion is widened or enlarged, so that the end portion of the drive shaft fixed is fixed in the receptacle of the rotary piston. Accordingly, by moving the conical elements in a second opposite direction of the expanded outer diameter in the end region of the drive shaft is reduced again to the original first outer diameter, so that the frictional engagement between the rotary piston and drive shaft is canceled and the rotary piston can be easily removed from the drive shaft.

According to one embodiment of the invention, the drive shafts are each formed as hollow shafts with a continuous cavity along their respective longitudinal axis. The rotary pistons each have on the side surface, which is assigned to the projecting into the pump space in the free end of the drive shaft, a receptacle for the arranged in the pump chamber end portion of the respective drive shafts. The cavity in the end region of the respective drive shaft arranged in the pump chamber has an expanded cross-section, that is to say the drive shafts are each designed to be thinned in the region of the rotary piston seat. In particular, the respective cavity in the pump chamber arranged in the end region of the respective drive shaft has an expanded cross-section with at least a second inner diameter which is greater than the first inner diameter of the continuous cavity along the longitudinal axis of the drive shaft. The drive shafts of the rotary lobe pump preferably each have a first outer diameter along their respective longitudinal axis. This first outer diameter can be expanded or enlarged in the end region of the drive shafts arranged in the pump space by means of the clamping and / or clamping device, so that the end region of the drive shafts is respectively firmly fixed in the respective receptacle of the rotary piston, in particular braced or jammed.

In particular, it is possible to press the drive shaft in the end region of the enlarged cross section in each case from inside to outside against the rotary piston inner side and thus to transmit the torques and axial forces without play from the drive shaft into the rotary piston. For this purpose, an already described above clamping and / or clamping device for fixing the rotary piston to the respective drive shaft is assigned to the extended cavity of the drive shaft and / or the recording of the rotary piston.

According to a preferred embodiment of the invention it is provided that a tool for acting on the clamping and / or clamping device can be introduced through the continuous cavity along the respective longitudinal axis of the drive shafts, in particular a tool for setting or releasing the clamping and / or clamping device.

For example, a tool is introduced through the cavity along the respective longitudinal axis of the respective drive shaft for maintenance work, with which the fixation of the rotary piston is released at the respective drive shaft. The tool is preferably removed from the cavity, but may also be during maintenance remain in the cavity, unless this interferes with the further steps. The rotary pistons and the respective sealing elements can now be removed from the respective drive shaft and fixed again after completion of the maintenance work by means of the tool.

In particular, the clamping and / or clamping device is adjusted by means of the introduced through the cavity tool such that the outer diameter is expanded or increased in the end region of the drive shaft. For disassembly, the clamping and / or clamping device is released by means of the introduced through the cavity tool, so that the outer diameter in the end region again corresponds to the first outer diameter along the longitudinal axis of the drive shaft and thus again a game between the end portion of the drive shaft and the receptacle of the rotary piston is trained.

The method for assembling or disassembling rotary pistons of a rotary piston pump may comprise, as an alternative or in addition to the described features, one or more features and / or properties of the device described above. Likewise, the device may alternatively or additionally comprise one or more features and / or properties of the described method.

A particular advantage over the prior art is that the pistons need not be fastened with a plurality of screws on the back of the pump housing, but only a fixation on a fixing point is necessary and no screws or other elements must be installed in the pump room.

figure description

• Figur 1 zeigt eine schematische Ansicht einer Drehkolbenpumpe gemäß dem bekannten Stand der Technik.
• Figur 2 zeigt eine erste Ausführungsform einer Befestigungseinrichtung zur Befestigung eines Drehkolbens auf einer Antriebswelle.
• Figur 3 zeigt eine Schnittdarstellung der ersten Ausführungsform der Befestigung eines Drehkolbens an einer Antriebswelle gemäß Figur 2 entlang einer Schnittlinie A-A.
• Figur 4 zeigt eine zweite Ausführungsform einer Befestigungseinrichtung zur Befestigung eines Drehkolbens auf einer Antriebswelle.
• Figur 5 zeigt eine dritte Ausführungsform einer Befestigungseinrichtung zur Befestigung eines Drehkolbens auf einer Antriebswelle.

In the following, embodiments of the invention and their advantages with reference to the accompanying figures will be explained in more detail. The proportions of the individual elements to one another in the figures do not always correspond to the actual size ratios, since some shapes are simplified and other shapes are shown enlarged in relation to other elements for better illustration.

• FIG. 1 shows a schematic view of a rotary piston pump according to the known prior art.
• FIG. 2 shows a first embodiment of a fastening device for fastening a rotary piston on a drive shaft.
• FIG. 3 shows a sectional view of the first embodiment of the attachment of a rotary piston to a drive shaft according to FIG. 2 along a section line AA.
• FIG. 4 shows a second embodiment of a fastening device for fastening a rotary piston on a drive shaft.
• FIG. 5 shows a third embodiment of a fastening device for fastening a rotary piston on a drive shaft.

For identical or equivalent elements of the invention, identical reference numerals are used. Furthermore, for the sake of clarity, only reference symbols are shown in the individual figures, which are required for the description of the respective figure. The illustrated embodiments are merely examples of how the device or method of the invention may be configured and are not an exhaustive limitation.

FIG. 1 shows a schematic view of a rotary piston pump 1 with two rotary pistons 8, 9 according to the known prior art. On a machine stand 2, a motor 3 is arranged. This drives two drive shafts 6,7 in opposite directions. Rotary pistons 8, 9, which are driven via the drive shafts 6, 7 and rotate simultaneously and in opposite directions about the axes of the drive shafts 6, 7, are arranged on the drive shafts in a pump housing 4. During the rotation of the rotary pistons 8, 9, there is always a contact between the rotary piston 8, 9 and the pump housing 4 of the rotary lobe pump 1. By forming thereby pumping chambers 5, the product to be conveyed is sucked, conveyed in the transport direction TR by the rotary lobe pump 1 and on the ejected opposite pump side. To seal the pump chamber from the environment seals (not shown) to the drive shafts 6, 7 are arranged.

FIG. 2 shows a first partial view of a first embodiment of an inventively designed rotary piston pump 30 with an attachment of a rotary piston 24 on a specially designed drive shaft 10 and FIG. 3 shows a sectional view of the first embodiment of the attachment of a rotary piston 24 on a drive shaft 10 according to FIG. 2 along a section line AA.

In the field of implementation of the drive shaft 10 through the pump housing 4, an installation space 20 for mechanical seals 22 or other suitable sealing elements for sealing the pump chamber from the environment is provided. The rotary piston 24 is arranged on the drive side of the drive shaft 10 opposite end portion 12 of the drive shaft 10. In particular, a receptacle 25 with a circular cross-section for receiving the drive shaft 10 is provided on the rotary piston 24. The attachment of the rotary piston 24 to the drive shaft 10 by means of a the end portion 12 of the drive shaft 10 associated clamping device 15th

The drive shaft 10 is formed as a so-called hollow shaft 11. In particular, a first cavity 13 extends along the longitudinal axis L of the drive shaft 10. The hollow shaft 11 has an outer diameter d1 over its entire length. Furthermore, the hollow shaft 11 has in regions a first inner diameter d2, which defines the first cavity 13.

The drive shaft 10 is configured in the end region 12, that is, in the region in which the rotary piston 24 is seated on the drive shaft 10 via the receptacle 25, thinned. In particular, in the end region 12 of the drive shaft 10, a second, widened cavity 14 is provided with a second inner diameter d3. The outer diameter d1 of the drive shaft 10 is greater than the second inner diameter d3 of the widened second cavity 14 in the end region 12 of the drive shaft 10, which is in turn greater than the first inner diameter d2 of the first cavity 13 along the longitudinal axis L of the drive shaft 10.

Due to the expansion of the second cavity 14 in the end region 12 of the drive shaft 10, the wall thickness W12 in this area is less than the general wall thickness W10 of the drive shaft 10. In particular, the general wall thickness W10 is calculated from 0.5 times the difference between the outer diameter d1 and the first inner diameter d2: $$\mathrm{<figure-callout\; id="10"\; label="W"\; filenames="imgf0002.png"\; state="\{\{state\}\}">W</figure-callout>}10=0.5\cdot \left(\mathrm{d}1-\mathrm{d}2\right),$$

The reduced wall thickness W12 in the end region 12 of the drive shaft 10 is calculated from 0.5 times the difference between the outer diameter d1 and the second inner diameter d3: $$\mathrm{<figure-callout\; id="12"\; label="W"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">W</figure-callout>}12=0.5\cdot \left(\mathrm{d}1-\mathrm{<figure-callout\; id="3"\; label="d"\; filenames="imgf0001.png"\; state="\{\{state\}\}">d</figure-callout>}3\right),$$

The receptacle 25 of the rotary piston 24 has an inner diameter which largely corresponds to the outer diameter d1 of the drive shaft 10, in particular the inner diameter of the receptacle 25 is slightly larger than the outer diameter d1, so that the rotary piston 24 with little play on the end portion 12 of the drive shaft 10th seated.

Due to the reduced wall thickness W12 of the drive shaft 10, it is possible to press the drive shaft 10 in the end region 12 from the inside to the outside against the receptacle 25 of the rotary piston 24. This leads to a rotationally fixed fixing of the drive shaft 10 in the receptacle 25 of the rotary piston 24. Thus, it is possible to transmit torque and axial forces backlash of the drive shaft 10 in the rotary piston 24.

The bracing of the rotary piston 24 at the end portion 12 of the drive shaft 10 can be done in various ways. Examples are the FIGS. 2 to 5 shown. For example, tapered elements can be inserted into the drive shaft 10 (see FIG FIGS. 4 and 5 ), or hydraulic and / or pneumatic elements (see FIGS. 2 and 3 ) be used.

According to the illustrated embodiment, the rotary piston 24 is closed on the side facing away from the drive shaft 10 side 26. Preferably, the rotary piston 24 is pushed onto the drive shaft 10, so that the end portion 12 of the drive shaft 10 is at least partially received in the receptacle 25 of the rotary piston 24.

The installation of the rotary piston 24 in the rotary piston pump 30 according to the invention is carried out according to a preferred embodiment of the invention in the following steps: First, a respective mechanical seal 22 is pushed onto the drive shafts 10, then a respective rotary piston 24 is slid onto the drive shafts 10. The rotary pistons 24 are aligned. For example, there is a template analogous to that in the DE 102012003066 B3 and in the DE 102013101185 A1 described prior art use. Subsequently, a tool is introduced through the cavity 13 from the drive side of the drive shafts 10 forth and by tightening / tightening the clamping device 15, the rotary piston 24 are fixed to the respective drive shaft 10.

According to one embodiment of the invention, the clamping device 15 is arranged in the receptacle 25 of the rotary piston 24. When sliding the rotary piston 24 on the drive shaft 10, the clamping device 15 is inserted into the second, enlarged cavity 14 of the end portion 12 of the drive shaft 10.

According to an alternative embodiment, the clamping device 15 is arranged in the second, enlarged cavity 14 of the end region 12 of the drive shaft 10, so that the rotary piston 24 is simultaneously pushed onto the drive shaft 10 and clamping device 15.

FIG. 4 shows a second embodiment of a fastening device for fastening a rotary piston (not shown) on a drive shaft 10b. It is provided here that the widened cavity 14b widens conically in the end region 12b in the direction of the rotary piston. The clamping means 15b is formed as a cone or truncated cone 35, wherein the cross section of the cone or truncated cone 35 decreases away from the rotary piston. The cone or truncated cone 35 has in the region of its bottom surface 36 an outer diameter dB which is at least slightly larger than the largest inner diameter d3max of the enlarged cavity 14b. To fix the rotary piston (not shown) on the drive shaft 10b of the truncated cone 36 is further inserted by means of a suitable tool in the enlarged cavity 14b of the drive shaft 10 or pulled in. This leads to an expansion of the outer diameter d1 (cf. FIG. 2 ) of the drive shaft 10b and thus to a tension in the receptacle 25 of the rotary piston 24 (see FIG. 2 ).

FIG. 5 shows a third embodiment of a fastening device for fastening a rotary piston 24c on a drive shaft 10c of a rotary piston pump 30c. In this case, the clamping means 15c is formed from a cone element 40 installed in the drive shaft 10c and a corresponding cone receptacle 28 arranged within the receptacle 25c of the rotary piston 24c.

When the rotary piston 24c is pushed onto the drive shaft 10c, the cone receptacle 28 is pushed onto the cone element 40 arranged in the widened cavity 14 of the end region 12 of the drive shaft 10.

For fixing the rotary piston 24c to the drive shaft 10c, the rotary piston 24c is further used by means of a suitable tool on the drive shaft 10c. The truncated cone 40 is thereby inserted further into the cone receptacle 28. This leads to an at least partial spreading of the cone receptacle 28. By a transmission of the Aufspreizkräfte on the wall of the drive shaft 10c in the end portion 12 with reduced wall thickness W12, the extension of the outer diameter d1 (see FIG. 2 ) causes the drive shaft 10c in this area and thus the Drive shaft 10c in the receptacle 25c of the rotary piston 24c (see also FIG. 2 ) braced.

The invention has been described with reference to a preferred embodiment. However, it will be apparent to those skilled in the art that modifications or changes may be made to the invention without departing from the scope of the following claims.

LIST OF REFERENCE NUMBERS

1

Rotary pump

2

machine stand

3

engine

4

pump housing

5

pump chamber

6

drive shaft

7

drive shaft

8th

rotary pistons

9

rotary pistons

10

drive shaft

11

hollow shaft

12

end

13

first cavity

14

second extended cavity

15

tensioning device

20

installation space

22

Mechanical seal

24

rotary pistons

25

admission

26

opposite side

28

taper

30

Rotary pump

35

truncated cone

36

floor area

40

cone element

d

diameter

L

longitudinal axis

TR

transport direction

W

Wall thickness

Claims (12)

1. A rotary piston pump (30) comprising at least two rotary pistons (24) arranged in a pump room on drive shafts (10) and rotating in opposite directions, wherein the rotary pistons (24) comprise an accommodation (25), and wherein the respective drive shaft (10) is arranged and secured with an end region (12) in the accommodation (25) of the respective rotary piston (24), characterized in that a diameter of the drive shafts (10) in the end region (12) can be elastically widened and that, in an operating state, in which the rotary pistons (24) are arranged on the respective drive shafts (10), a frictional connection or a frictional and positive connection is formed between the respective accommodation (25) of the rotary piston (24) and the end region (12) of the respective drive shaft (10), so that the transmission of force takes place free from play, wherein the drive shafts (10) are each embodied as hollow shafts (11) comprising a continuous hollow space (13) comprising a first inner diameter (d2) along the respective longitudinal axis (L) thereof, that, in the end region (12) of the respective drive shaft (10), which is arranged in the pump room, the respective hollow space has a widened cross section comprising at least a second inner diameter (d3), wherein the at least one second inner diameter (d3) is greater than the first inner diameter (d2).
2. The rotary piston pump (30) according to claim 1, wherein a tensioning and/or clamping device for securing the rotary pistons (24) to the respective drive shaft (10) by means of frictional connection is assigned to the drive shaft (10) and/or to the accommodation (25) of the rotary piston (24).
3. The rotary piston pump (30) according to claim 2, wherein the tensioning and/or clamping device comprises size-variable hydraulic and/or pneumatic elements or wherein the tensioning and/or clamping device comprises mechanical elements (35, 40).
4. The rotary piston pump (30) according to one of the preceding claims, wherein the drive shafts (10) each have a first outer diameter (d1) along the respective longitudinal axis (L) thereof, wherein, in the end region (12), which is arranged in the pump room, the first outer diameter (d1) can be widened and/or enlarged by means of the tensioning and/or clamping device.
5. The rotary prison pump (30) according to one of the preceding claims, wherein a tool for acting on the tensioning and/or clamping device can be introduced through the continuous hollow space (13) along the respective longitudinal axis (L) of the drive shafts (10) .
6. A method for securing at least two rotary pistons (24) rotating in opposite directions to respectively assigned drive shafts (10) in the pump room of a rotary piston pump (30), characterized by the following method steps:

   • sliding the rotary pistons (24) onto a free end region (12) of the respective drive shaft (10) arranged in the pump room;

   • aligning the rotary pistons (24) with the respective drive shafts (10);

   • widening the end region (12) of the drive shafts (10) to establish a frictional connection between an accommodation (25) of the rotary piston (24) and the end region (12) of the drive shaft (10) for securing the rotary piston (24),

   • wherein the widening of the end region (12) takes place by means of a tool, which is inserted through a hollow space (13) along the respective longitudinal axis (L) of the respective drive shaft (10).
7. The method according to claim 6, wherein the widening of the end region (12) of the drive shaft (10) takes place by means of a tensioning and/or clamping device assigned to the end region (12) of the drive shaft (10) and/or the accommodation (25) of the rotary piston (24) .
8. The method according to claim 7, wherein the tensioning and/or clamping device comprises hydraulic and/or pneumatic elements, wherein the end region (12) of the drive shaft (10) inside the accommodation (25) of the rotary piston (24) is widened by filling a suitable hydraulic fluid and/or of a suitable gas into the tensioning and/or clamping device.
9. The method according to claim 8, wherein the tensioning and/or clamping device comprises mechanical elements in the form of taper elements (35, 40), wherein the end region (12) of the drive shaft (10) is widened by displacing the taper elements (35, 40) in the region of the accommodation (25) of the rotary piston (24) and/or inside the end region (12) of the drive shaft (10) arranged inside the pump room inside the accommodation (25) of the rotary piston (24).
10. The method according to one of claims 6 to 9, wherein the rotary piston (24) is secured to the respective drive shaft (10) by adjusting the tensioning and/or clamping device, so that torques and axial forces are transmitted from the drive shaft (10) into the rotary piston (24) free from play.
11. The method according to one of claims 6 to 10, wherein the tensioning and/or clamping device is adjusted by means of a tool in such a way that an outer diameter (d1) of the end region (12) of the respective drive shaft (10) arranged in the pump room is widened by means of the tensioning and/or clamping device inside an accommodation (25) of the rotary piston (24) and the end region (12) of the drive shaft (10) releasably jams inside an accommodation (25) of the rotary piston (24).
12. A method for disassembling at least two rotary pistons (24) running in opposite directions from the respectively assigned drive shafts (10) in the pump room of a rotary piston pump (30) according to one of claims 1 to 6, characterized by the following method steps:

    • releasing the frictional connection between the accommodation (25) of the rotary piston (24) and the end region (12) of the drive shaft (10) by decreasing an outer diameter of the end region (12) of the drive shaft (10),

    • wherein the releasing of the frictional connection takes place by means of a tool, which is inserted through a hollow space (13) along the respective longitudinal axis (L) of the respective drive shaft (10) and

    • removing the rotary piston (24) from the respective drive shaft (10).

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