WO2019037888A1

WO2019037888A1 - Method for producing a rotary piston for a screw spindle pump

Info

Publication number: WO2019037888A1
Application number: PCT/EP2018/000376
Authority: WO
Inventors: Thomas Coenen
Original assignee: Pumpenfabrik Wangen Gmbh
Priority date: 2017-08-22
Filing date: 2018-07-27
Publication date: 2019-02-28
Also published as: DE102017007832A1

Abstract

In the case of a method for producing a conveying element (3) for a twin-screw machine as a positive displacement pump, in particular a screw spindle pump, rotary piston pump or annular piston pump, with a form-fitting geometry (5) on a first region of the conveying element (3) for applying a torque to the conveying element (3) and with a conveying geometry on a second region of the conveying element (3) for conveying a medium by means of the conveying geometry, wherein the form-fitting geometry (5) and the conveying geometry each form a functional geometry (60), with a machine tool by the following steps: to provide a blank having a first functional geometry (60), machining a second region of the blank with a tool, so that a second functional geometry is machined on the blank, it is intended that, for maintenance purposes, the conveying elements (3) can be exchanged on the twin-screw machine (1) as a positive displacement pump easily, quickly and with little assembly effort. This object is achieved by the position of the first functional geometry (60) in relation to the machine tool being sensed by at least one position sensing means, data concerning a prescribed position of the second functional geometry to be machined in relation to the first functional geometry (60) on the blank being stored in a data memory and the second functional geometry being machined with the tool in dependence on the position sensed by the at least one position sensing means and the data stored in the data memory, so that the second functional geometry is machined into the blank in the prescribed and stored position in relation to the first functional geometry (60).

Description

Method for producing a rotary piston for a

Screw Pump

DESCRIPTION

The present invention relates to a method for producing a conveying element for a twin-shaft machine as a positive displacement pump according to the preamble of claim 1, a method for replacing at least one previous conveying element of at least one twin-shaft machine as a positive displacement pump according to the preamble of claim 12 and a screw pump according to the preamble of claim 15 ,

Two-shaft machines as displacement pumps, in particular screw pumps, are used in a wide variety of technical applications for conveying media in the food, cosmetics and chemical industries with a different viscosity, in particular for viscous media. These media include, for example, beverages, dairy products, chocolate, sugar, liquid sugars, creams or adhesives.

The twin-shaft machines as a positive displacement pump comprise two conveying elements with a conveying geometry and a positive locking geometry. The conveying elements are rotatably connected with a respective shaft without play by the positive engagement geometry engages each of a conveying element positively in a complementary Gegenformschlussgeometrie on the shaft. The waves and thus also the conveying elements are offset by a drive motor in a rotational movement, so that the delivery geometries of the

CONFIRMATION COPY Conveying elements promote the medium. The shafts are mechanically coupled to each other, in particular with gears, so that the shafts and thus also the conveying elements are aligned with conveyor geometries in a fixed predetermined rotational position to each other. The conveyor geometries of the rotating conveyor elements thus have for each rotational position of the conveying elements a fixed predetermined orientation to each other, which is necessary for the conveying of the medium.

The conveying elements, generally made of metal, in particular stainless steel, are produced from a blank by machining with a machine tool. The conveyor geometry is incorporated with a tool in the attached to the mandrel blank, wherein in the blank already the positive locking geometry is incorporated. In this production is not taken into account in which position or relative position, in particular rotational position, the interlocking geometry and the conveyor geometry are aligned with each other. This means that the position, in particular rotational position, the positive locking geometry and the conveying geometry to each other randomly and arbitrarily results. In the production of twin-shaft machines with an adjusting member, the rotational positions of the shafts so that the conveying elements are changed so that the conveying geometries of the conveying elements have a predetermined rotational position for each rotational position to each other, d. H. the conveying elements are aligned during rotation in each rotational position in a predetermined, fixed rotational position to each other and this is referred to as synchronizing the conveying elements to each other. This synchronization is necessary because a chain mechanical couplings is responsible for the position of the conveying elements to each other, for example, the mechanical coupling of the two shafts with each other with gears and the alignment of the position of the positive locking geometry and the geometry of the conveyor to each other on the conveyor elements.

The conveying geometries of the conveying elements are subject to mechanical wear, in particular due to abrasion, the particular in granular too promotional media increasingly occurs. For this reason, it is necessary to replace the conveying elements after a certain number of operating hours of conveying a medium with the twin-shaft machine as a positive displacement pump. However, since in the production of conveying elements as Austauschförderelementen the position of the Formschiussgeometrie and the feed geometry to each other are randomly these are different between a previous still exchangeable conveyor element and a new exchange conveyor element. For this reason, therefore, a complex synchronization of the conveying elements to each other with the adjustment is necessary when replacing the conveyor elements. With the adjusting member, the rotational position of the shafts and thus the conveying elements is changed to each other. However, this is expensive, because this is a high level of craftsmanship when working on gears and the adjustment is necessary and usually a drainage of lubricating oil is required. In particular, when using the twin-shaft machine in the food industry, the discharge of lubricating oil is problematic.

In a screw pump as a twin-shaft machine, the conveying elements are designed as rotary pistons with internal teeth as Formschiussgeometrie as a first functional geometry at a bore and with a thread-shaped profiling as conveying geometry as a second functional geometry on the outside of the rotary piston.

DE 10 2012 001 700 B4 shows a single-spindle screw pump in a single-flow construction with a pump housing having a pump section, a bearing section and a gear section with a gear housing, wherein the bearing section and the pump section are designed separately from each other with a conveyor housing part as part of the pump section, in which two shaft-mounted conveying screws are provided with flanks, wherein the shafts are mounted in the bearing portion (outer bearing) and extend into the gear section, arranged on the shafts in the gear section gears, by means of which the shafts are rotationally coupled, with one on the shaft in operative connection with these arranged fastening element for producing a holding connection between the shaft and gear, wherein the fastening element and the gearwheel have corresponding bores via which a holding connection between the gear and the fastener via a locking element can be produced, wherein the holes in the fastener are designed so that the Gear and the fastener (and thus the shaft) are rotated against each other, so that a distance between the flanks of the conveyor screws (the backlash of the conveyor screws) is adjustable, that the transmission portion of the pump housing, an opening is provided that the opening provided with a detachable cover in that the opening is arranged so that the cover can be released in the installed state of the spindle pump, that the gear space for adjusting the backlash of the conveyor screws can be reached with the necessary tool that the holes in the fastening element are provided as a radial slot, in which the locking element in the inserted but not locked state is radially displaceable, and that the radial length of the slot is provided so that its end points coincide at least with the points of contact of the flanks of the conveyor screws. Adversely, thus adjusting the backlash of the conveyor screws, ie the synchronization of the conveyor elements to each other with the adjusting necessary when replacing the conveyor elements as conveying screws or rotary pistons in a screw pump as twin-shaft machine as a positive displacement pump.

DE 10 2014 1 17 166 B4 shows a method for fixing at least two oppositely rotating rotary pistons to respectively associated drive shafts in the pump chamber of a rotary piston pump with the following method steps: pushing the rotary pistons onto a free end region of the respective drive shaft arranged in the pump chamber, aligning the rotary pistons the respective drive shafts, widening of the end portion of the drive shafts for producing a frictional engagement between the receptacle of the rotary piston and the end portion of the drive shaft for fixing the rotary piston, wherein the expansion of the Endbereiches means of a tool which is inserted through a cavity along the respective longitudinal axis of the respective drive shaft. The object of the present invention is to provide a method for producing a conveying element for a twin-shaft machine as a positive displacement pump, a method for replacing at least one previous conveying element at least a twin-shaft machine as a positive displacement pump and a screw pump at which the conveying elements for maintenance purposes on the twin-shaft machine as positive displacement pump can be easily, cleanly and quickly replaced with a low installation effort without synchronizing conveyor elements with an adjusting. This object is achieved with a method for producing a conveying element for a twin-shaft machine as a positive displacement pump, in particular screw pump, rotary pump or rotary piston pump, with a form-fitting geometry at a first region of the conveying element for applying a torque to the conveying element and with a conveying geometry at a second region of the conveying element for conveying a medium by means of the conveying geometry, wherein the positive locking geometry and the conveying geometry each form a functional geometry with a machine tool comprising the steps of: providing a blank having a first functional geometry, machining a second region of the blank with a tool such that a second functional geometry is incorporated in the blank, wherein the position of the first functional geometry relative to the machine tool is detected with at least one position detection means in a data memory stored and / or are stored and the second function geometry depending on the detected position with the at least one position detection means and the data stored in the data memory with the tool . so that the second functional geometry is incorporated in the predetermined and preferably stored position to the first functional geometry in the blank. In the case of the conveying elements produced by the method, the first functional geometry and the second functional geometry are thus aligned in a substantially identical predetermined and preferably stored position, so that when the conveying element is replaced, no synchronization of the conveying elements relative to one another is necessary. In this case, conveyor elements can also be produced with the method in which the first functional geometry and the second functional geometry are aligned with one another in a different predetermined and stored position. For this purpose, for example, only in a CNC machine tool, the data stored in an electronic data storage to be changed. In order for conveyor elements for replacement for maintenance purposes can be prepared for different twin-shaft machines as positive displacement pumps without the need for synchronization of Austauschförderelemente. With the data stored in the data memory and the detected position, a calculation is performed so that the tool performs the necessary relative movement path to the blank.

In a further variant, the blank having the first functional geometry is made available by a machining of a first region of the blank with the tool being carried out, so that the first functional geometry is incorporated on the blank, in particular with a machine tool.

Preferably, first the first functional geometry is machined into the blank and then the position of the first functional geometry with the at least one position detecting means is detected to the machine tool.

In an additional embodiment, with the at least one position detection means an axial position and / or a rotational position the first functional geometry, in particular by means of at least one formed on the blank position indicator, detected to the machine tool. The position indicator can be designed, for example, as an optical marking and / or as the first functional geometry and / or as a transponder attached to a specific position.

In a supplementary embodiment, the position of the first functional geometry to the machine tool with a position detecting means as a sensor, in particular a movable mechanical scanning member and / or an optical sensor with a laser, indirectly or directly, is detected. Suitably, the position detection means is designed as a camera with an image processing software.

In a further refinement, the position, in particular the rotational position, of the first functional geometry relative to the machine tool is detected with a position detection means as a position gauge, and a position counter-form geometry is formed on the position gauge and the position counter-form geometry is brought into mechanical contact with a position locking geometry on a receiving mandrel.

In an additional embodiment, the position gauge has an index, in particular an index area, and the index is formed in a predetermined position relative to the position counter-form geometry, so that during the mechanical contact between the position counter-form geometry on the position gauge and the form fit geometry on the mandrel, the index in a predetermined position is aligned to the Positionformschlussgeometrie on the mandrel.

In an additional embodiment, the rotational position of the index and thus also the rotational position of the position-locking geometry with the at least one position-detecting means are detected during the mechanical contact between the position counter-form geometry on the position gauge and the position-fit geometry on the arbor. The index is oriented in a known rotational position relative to the position counter-geometry of the position gauge and the rotational position position Umschlussgeometrie corresponds to the rotational position of the first functional geometry at a rotationally fixed positive connection between the first functional geometry of the blank and the position-locking geometry of the mandrel such that from rotational position of the index, the rotational position of the first Function geometry can be calculated.

In another embodiment, the index is moved as an index surface and thus also the position gauge together with the mandrel in a predetermined rotational position, then the predetermined rotational position of the index is used in a coordinate system of the machine tool and the position gauge is removed from the mandrel and the blank is pushed onto the mandrel, so that the first functional geometry is brought to the blank in mechanical rotationally fixed positive contact with the Formformschlussgeometrie on the mandrel and the rotational position of the first functional geometry of the blank in the coordinate system of the machine tool is derived from the rotational position of the index.

In a further variant, after detecting the position of the first functional geometry relative to the machine tool and during the machining of the second functional geometry in the blank with the tool, the blank is fixed in a fixed axial position and / or rotational position to the machine tool and / or after Detecting the position of the first functional geometry to the machine tool and during the machining of the second functional geometry in the blank with the tool, the blank is changed in its axial position and / or rotational position to the machine tool and the change of the axial position and / or rotational position of the blank becomes the machine tool calculated, so that during the machining of the second functional geometry in the blank with the tool, the position of the first functional geometry of the blank is calculated to the machine tool and depending on the calculated position of the first functional geometry of the blank to the machine tool, the second functional geometry with the tool is incorporated.

In a supplementary embodiment, the first functional geometry is the form-fitting geometry and the second functional geometry is the conveying geometry, in particular the conveying element is a rotary piston of a screw pump and the first functional geometry as the positive locking geometry is an internal toothing on an axial bore of the rotary piston and the second functional geometry as the conveying geometry an outer side of the rotary piston is formed as a thread-shaped profiling, or the first functional geometry is the conveying geometry and the second functional geometry is the positive locking geometry.

Method according to the invention for exchanging at least one previous conveying element of at least one twin-shaft machine as displacement pump, in particular screw pump,

Rotary pump or rotary piston pump, each with two conveying elements and each with two shafts, each rotatably connected to a respective conveying element with one shaft and on each of which a conveying element is a form-fitting geometry for applying a torque to the conveying element by means of a Gegenformschlussgeometrie formed on a shaft and on the shaft, the Gegenformschlussgeometrie is formed, with the steps: provide at least one Austauschförderelement, moving out of at least one previous conveyor element from a pumping room and removing the at least one previous conveyor element of the at least one twin-machine, so that the mechanical contact between the ever a positive locking geometry of the previous at least one conveying element and the counter-form-fitting geometry of the at least one shaft is canceled, introducing the at least one Austauschförderelementes in the at least one delivery chamber and attaching the at least one Austauschförderelementes on at least one shaft, so that the mechanical contact between each a positive locking geometry of the at least one Austauschförderelementes and each a Gegenformschlussgeometrie the at least one wave is produced and the at least one exchange conveyor rotatably with the at least one exchange conveyor element is made available by the at least one exchange conveyor element being produced with a method described in this patent application and / or in the previous at least one conveyor element and in the at least one replacement conveyor element each having a positive locking geometry and each of which a conveying geometry in a substantially identical position, in particular rotational position, are aligned with each other.

In another variant, after fixing the at least one exchange conveying element to the at least one shaft, the rotational position of the two shafts of each two-shaft machine remains constant relative to each other, in particular no adjusting member for changing the rotational position of the two shafts to each other as synchronizing the two conveying elements on the each operated a twin-shaft machine, and / or at a plurality of twin-shaft machines is or are ever a conveying element, preferably two conveying elements, replaced. In a supplementary embodiment, the previous conveying element and the replacement conveying element is a rotary piston of a screw pump and the positive locking geometry is an internal toothing on an axial bore and the conveying geometry is formed on an outer side of the rotary piston as a thread-shaped profiling. In a screw pump pump usually engage the conveyor geometries as the thread-shaped profiles in an arrangement of the rotary pistons on the shafts, so that usually two rotary pistons must be replaced simultaneously, the two exchanged rotary pistons are usually two exchange conveyor elements. However, only one can remote rotary piston be an exchange conveyor and the other rotary piston is the previous rotary piston, ie that a rotary piston is fixed after moving out of the pumping chamber again together with the exchange conveyor on the shafts. In a screw pump thus two rotary pistons are provided as exchange conveyor elements available and replaced.

Screw shaft pump according to the invention, comprising a housing, two rotary pistons as conveying elements, which are arranged within a pumping chamber of the housing limited delivery space, two mechanically coupled to each other waves, the two rotary pistons are rotatably connected to one shaft, two axial seals for sealing the pumping chamber a safety space, each having a first dynamic sealing receptacle and a second static sealing receptacle, wherein the first dynamic sealing receptacle is rotatably connected directly or indirectly to the shaft and the second static sealing receptacle is attached directly or indirectly to the housing and at the first dynamic seal receptacle a first dynamic Mechanical seal is attached and attached to the second static seal receiving a second static mating ring seal, wherein a radial inner portion of the first dynamic seal receptacle in an annular groove in particular between n rotary piston and / or shaft and / or a first stop element, is arranged and the axial extent of the annular groove on the radial inner portion of the first dynamic sealing seat is greater than the axial extent of the radial inner portion of the first sealing seat in the annular groove. The axial extent is the extension or length in the axial direction and / or direction of the axis of rotation of the shaft. Method according to the invention for producing a twin-shaft machine, in particular a screw pump, with the steps: making available components of the twin-shaft machine, in particular the screw pump, in particular a housing, two conveying elements, in particular two rotary pistons, two shafts, one mechanical coupling device, in particular two gears, for the mechanical coupling of the two shafts, an adjusting member, mounting the components to the twin-shaft machine, in particular screw pump by mechanically coupling the two shafts with the mechanical coupling device, the two conveying elements, in particular two rotary pistons, positive and rotationally fixed connected to the two shafts and the conveying elements, in particular rotary pistons, are synchronized with each other with the adjusting member, wherein the two conveying elements, in particular two rotary pistons, are made available by the two conveying elements, in particular two rotary pistons, produced with a method described in this patent application become.

Appropriately, the rotational positions of the two shafts are mutually changed during synchronization with the adjusting member and after reaching the necessary rotational position of the two shafts to each other, the rotational position of the two shafts is fixed to each other with the adjustment. In particular, the rotational position of the two shafts is fixed to each other by the rotational position of each of a shaft and a gear on the shaft is fixed to each other with the adjusting member. Appropriately, the rotational positions of the two shafts are changed to each other when synchronizing with the adjusting member by the rotational positions of a respective shaft and a gear on the shaft to each other are changed. Preferably, the synchronization is performed while the conveying elements are rotatably connected to the waves.

In a further variant, at least one conveying element and at least one exchange conveying element are each aligned with one positive locking geometry and / or the one conveying geometry in a substantially identical axial position, in particular each have a positive locking geometry and / or the one each Conveying geometry on a substantially identical distance to an axial end of the at least one exchange conveyor element. In a further embodiment, identical conveying elements are produced geometrically, essentially at least partially, in particular completely, in particular with different machine tools and / or in particular with different receiving mandrels. The different receiving mandrels have only a substantially identical position-locking geometry for the rotationally fixed positively locking connection with a first functional geometry of the blank and the conveying element. The rotational position of the position-locking geometry relative to the machine tool is to be detected by the at least one position detection means, so that the rotational position derived therefrom or calculated first function geometry is known to the machine tool and thus the control and / or regulating unit is available and the first functional geometry is during the machining in a rotationally positive form-locking connection with the position-locking geometry of the mandrel. Deviating from this, the rotational position of the first functional geometry can also be detected without the receiving mandrel with the at least one position-detecting means, in particular a sensor. The substantially at least partially, in particular completely, identical conveying elements can thus be produced, in particular independently of the machine tool used and / or the receiving device, because the position of the first functional geometry relative to the machine tool is detected and this detected position is used for the incorporation of the second functional geometry becomes. The substantially identical conveyor elements have differences due to inaccuracies, in particular measurement and manufacturing inaccuracies on. However, the inaccuracies achieved have no influence on the functionality of the twin-shaft machine as a displacement pump when replacing the conveyor elements. In partially substantially identical conveying elements, the first and second functional geometry are aligned in a substantially identical rotational position to each other and the axial extent of the conveying elements is different. A rotational position of the conveyor element or other parts or components is a position which is at an angle in a plane perpendicular to a Rotation axis of the conveying element or the other part can be described and having the angle between two half-lines in the plane and the two half-lines as the starting point, the axis of rotation. A rotational position difference of the conveying element or another part can thus be described with the angle.

In a further embodiment, the rotational position difference between the predetermined desired rotational position and the actual rotational position of the second functional geometry due to inaccuracies, in particular measurement and manufacturing inaccuracies, the conveying elements produced by the method is less than 0.5 °, 0.1 °, 0 , 05 °, 0.04 °, 0.01 °, 0.005 ° or 0.001 °. The relevant rotational position difference occurs at the radial end portion of the impeller because there may or may be contact between the impellers at the radial end portion.

In a further embodiment, the axial position difference between the predetermined axial nominal extent and the axial actual extent of the conveying element due to inaccuracies, in particular measurement and manufacturing inaccuracies, the conveying elements produced by the method is less than 0.5 mm, 0.1 mm , 0.05 mm, 0.01 mm, 0.005 mm or 0.001 mm. The axial extent of the conveying element is in particular the maximum extent or length of the conveying element in the direction of the longitudinal or rotational axis of the conveying element. In a further embodiment, the first region of the conveying element with the first functional geometry and the second region of the conveying element with the second functional geometry are two separate regions and / or regions on the environmental side of the conveying element. As an environment side of the conveying element, an area that can be contacted by the environment is considered, so that one side of the conveying element at a bore is also regarded as an environmental side or surface of the conveying element. In a further embodiment, the housing of the screw pump comprises a pump section and a bearing section and preferably a gear section. Suitably, the housing of the twin-shaft machine, in particular screw pump, a plurality of parts.

In a further variant, the first dynamic sealing seat indirectly or directly rotationally fixed to the shaft positively and / or non-positively connected, in particular a radial inner side of the first dynamic sealing seat indirectly or directly rotatably connected to a radial outer side of the shaft form-fitting and / or non-positively connected; for a frictional connection, the first dynamic sealing seat with a compressive force is directly or indirectly on the shaft and / or the rotary piston, in particular is a radial inner side of the first dynamic sealing seat directly or indirectly on a radial outer side of the shaft and / or the rotary piston and For a positive connection, the first dynamic sealing seat with a Radialformschlussgeometrie indirectly or directly positively connected with a Gegenradialformschlussgeometrie on the shaft and / or the rotary piston, in particular a Radialformschlussgeometrie on a radial inner side of the first dynamic seal recording directly or indirectly with a Gegenradialformschlussgeometrie the radial outer side of the shaft and / or the rotary piston connected.

In a supplementary embodiment, the radial inner portion of the dynamic sealing seat and a stop ring are arranged in the annular groove. Suitably, the radial inner portion of the dynamic sealing receptacle is arranged radially outside of the stop ring. In a further embodiment, the radial inner portion of the dynamic sealing seat has a greater radial distance to the axis of rotation of the shaft than the stop ring. In a further embodiment, the position-locking geometry of the receiving mandrel is essentially identical to the counter-form-closure geometry of the shaft.

Suitably, the Positiongegenformschlussgeometrie the position gauge is substantially identical to the form-fitting geometry of the conveyor element formed.

Preferably, the position-locking geometry of the receiving mandrel and the position counter-form-locking geometry of the position gauge are designed to be complementary.

In a further embodiment, the positive locking geometry of the conveying element and the counter-form-fitting geometry of the shaft are designed to be complementary.

In a further embodiment, the axial extent of the stop ring in the axial direction is greater, in particular by at least 1%, 2%, 3%, 5% 7%, 10% or 15% greater than the axial extent of the arranged in the annular groove radial inner portion of the first dynamic sealing receptacle. Due to the sufficiently large difference in the extent in the axial direction so manufacturing inaccuracies can be compensated, so that the radial inner portion of the radial sealing seat no axial compressive force, in particular no permanent axial compressive force is exposed.

In a further embodiment, the first stop element is integrally formed with the rotary piston or the shaft or formed as a separate component in addition to the rotary piston or the shaft, in particular as a stop ring. In a further embodiment, an axial movement of the rotary piston to the shaft in the direction of the gears is blocked exclusively by the first stop element and / or not blocked by the first dynamic seal receptacle.

Preferably, the possible minimum axial distance of the rotary piston to the gears is exclusively blocked by the first stop element and / or not blocked by the first dynamic seal seat.

In a further embodiment, the machine tool is a CNC machine tool, in particular, the CNC machine tool is programmable. Preferably, the machine tool is a lathe and / or a milling machine.

In a further embodiment, the conveying elements made of metal, in particular stainless steel, are formed.

, ^. :

In a further embodiment, the conveying elements are gear wheels with teeth as the conveying geometry and preferably a form fit geometry as a threaded, bayonet or bolt connection between the shaft and the conveying element. Preferably, each geometry is considered as a positive locking geometry for a positive rotational connection between the conveyor element and the shaft.

Suitably, the conveying elements are rotary piston of a rotary piston pump. In a further variant, the data memory is exclusively an electronic data memory. For the control of the movement of the tool for machining the second functional geometry, therefore, no mechanical data memories are used, ie with one sensor the position of the first Function geometry is detected to the machine tool and depending on the position of the first functional geometry and the data stored in the electronic data memory, with respect to a predetermined position of the incorporated second functional geometry to the first functional geometry on the blank, the second functional geometry is incorporated into the blank.

Expediently, the twin-shaft machine comprises a positive displacement pump, in particular the screw pump, a drive motor, in particular an electric motor or internal combustion engine or hydraulic motor.

In a further variant, the blank having the first functional geometry is made available by producing the blank by means of prototyping and / or forming.

Preferably, the conveying elements, in particular a driven shaft, are mechanically coupled by means of a gear with the drive motor. Preferably, the transmission is a reduction gear, so that a drive shaft of the drive motor has a greater speed than the conveying elements, in particular the driven shaft.

In a further embodiment, during operation of the twin-shaft machine with proper synchronization, the conveying elements are not in contact with each other.

The invention further comprises a computer program with program code means which are stored on a computer-readable data carrier in order to carry out a method described in this patent application when the computer program is executed on a computer or a corresponding computing unit.

A component of the invention is also a computer program product with program code means which are stored on a computer-readable data medium are stored to perform a method described in this patent application when the computer program is executed on a computer or a corresponding computing unit. A computer program product is a data carrier, in particular a CD, a ROM, a RAM, a USB stick or a hard disk drive (HDD), and / or a computer with the data carrier.

Hereinafter, embodiments of the invention will be described in more detail with reference to the accompanying drawings.

It shows: a perspective view of a screw pump, a longitudinal section of the screw pump in the region of a housing with a pump, bearing and gear section, a perspective view of two gears, each rotatably connected to a shaft, the screw pump, a perspective view of a a first rotary piston of the screw pump, a perspective view of a second rotary piston of the screw pump, a partial longitudinal section and a partial side view of a rotary piston of the screw pump, an enlarged view of an axial seal between the pumping chamber and the safety space of the screw pump, a perspective view of a mandrel,

9 is a perspective view of a position theory, a longitudinal section of the attached to a machine tool mandrel, Fig. 11 shows a longitudinal section of the attached to the machine tool

Mandrel with a fixed to the mandrel blank and

Fig. 12 is a longitudinal section of the attached to the machine tool

Mandrel with a attached to the mandrel

Rotary piston after the machining of the blank with the machine tool to the rotary piston.

1 to 7, a screw pump 2 is shown as a twin-shaft machine 1 as a positive displacement pump 1. The screw pump 2 is used to convey a variety of media, such as antifreeze, lubricating oil, glue or ice cream, with different viscosity. A multi-part housing 9 has a pump section 10, a bearing section 13 and a gear section 14. The pump section 10 has a radial wall 11 and an axial wall 12. The pump section 10 defines a delivery chamber 23 for conveying the medium and the radial wall 11 limits the delivery chamber 23 in the radial direction 32 and the Axialwandung 12 limits the delivery chamber 23 in the axial direction 31. In the radial wall 11 is an inlet port 21 for the medium and in the lid-like axial wall 12 is formed an outlet opening 22 for the medium. The peripheral Axialwandung 12 and the cap-like radial wall 11 can be easily removed from the rest of the housing 9 for cleaning the delivery chamber 23rd

In the housing 9, two shafts 15, namely a driven first shaft 16 and a driven second shaft 19, mounted with bearings 28. Needle bearings 29 and ball bearings 30 are mounted on the bearing section 13 for supporting the two shafts 15. A part 18 of the driven first shaft 16 is guided through an opening outside the housing 9, namely outside of the gear portion 14 of the housing 9, and on this part 18, a clutch 33 is attached. At the opening an axial seal 27 is attached for sealing. The bearing section 13 and the gear section 14 of the housing 9 delimit a space 24 filled with lubricating oil. In the axial direction 31, a safety space 25 filled with air is formed between the conveying space 23 and the space 24. The safety space 25 is sealed with an axial seal 36 to the space 24 filled with lubricating oil. An axial seal 26 seals the delivery chamber 23 to the security room 25 from. On the housing 9, a viewing window is attached, so that in case of leakage of the axial seal 26 medium in the security space 25 can be optically detected from the outside or at a leakage of the axial seal 36 lubricating oil in the security room 25 can be visually recognized from the outside.

An electric motor 34 as a drive motor 35 drives the driven first shaft 16. For this purpose, a counter-coupling is fixed to a drive shaft of the electric motor 34, not shown, and the counter-coupling is positively connected to the clutch 33, so that from the electric motor 34 to the driven first shaft 16th a torque can be applied. On the driven first shaft 16, a first gear 17 is at least rotationally fixed and on the driven second shaft 19, a second gear 20 is at least rotationally fixed. The teeth of the first and second gears 17, 20 mesh with each other so that the second shaft 19 is driven by the first shaft 16 and the first shaft 16 and the second shaft 19 have an opposite rotational movement about the one axis of rotation 38 as a longitudinal axis 39 of the shafts 15 execute. The rotationally fixed connection between the driven second shaft 19 and the second gear 20 is formed with an adjusting member 49. The adjusting member 49 allows in the preparation of the screw pump 2, the first synchronization of the conveyor geometries 7 of the rotary piston 4 as conveying elements 3 to each other by the adjusting member 49, the rotational position of the driven second shaft 19 is changed to the second gear 20 and then for the subsequent operation is set again, so that the orientation of the conveyor geometries 7 of the rotary piston 4 is changed. The adjusting member 49 thus serves only in the manufacture of the screw pump 2 to bring the delivery geometries 7 of the rotary piston 4 in the correct orientation to each other. This is necessary because in the production of a chain of mechanical couplings for the alignment of the conveyor geometries 7 of the rotary piston 4 is responsible to each other and not only the position of the conveyor geometries 7 and the positive locking geometry 5 of the rotary piston 4 to each other. For example, in the chain of mechanical couplings for the alignment of the conveyor geometries 7 of the rotary piston 4 to each other and the gears 17, 20 and the rotational position of the first gear 17 to the driven first shaft 16 are responsible. The conveying of the medium in the conveying space 23 from the inlet opening 21 to the outlet opening 22 is carried out by two conveying elements 3 as the two rotary piston 4. The rotary pistons 4 are formed in a cylinder jacket with an axial bore 37. At the radial inner side of the axial bore 37, the positive locking geometry 5 is formed as an internal toothing 6 at an axial section of the axial bore 37. On the radial outer side of the rotary piston 4, the conveying geometry 7 is formed as a thread-shaped profiling 8. The form-fitting geometry 5 forms a first functional geometry 60 at a first region of the rotary piston 4. The conveying geometry 7 forms a second functional geometry 61 at a second region of the rotary piston 4. Axial bores 37 of the rotary pistons 4 have an axial end region per shaft 15. At an axial portion of the axial end portion of the shafts 15 a Gegenformschlussgeometrie 40 is formed as an external toothing 41. The teeth of the external teeth 41 each of a shaft 15 mesh with the teeth of the internal toothing 6 each of a rotary piston 4, so that the rotary piston 4 rotatably and positively connected to the shafts 15. The two rotary pistons 4 thus perform an opposite rotational movement about the axis of rotation 38 as the longitudinal axis 39 of the shafts 15, because the rotary pistons 4 are coaxially fixed to the shafts 15. The axial movement the rotary piston 4 in the direction of the outlet opening 22 is blocked, each with an axial stopper head 42 as a second stop member 45 and the stopper head 42 is axially fixed with a nozzle 43 on the shaft 15. The axial movement of the rotary pistons 4 in the direction of the gears 17, 20 is blocked by a first stop element 44. Depending on a rotary piston 4 are thus axially fixed in the axial direction 31 between the first stop member 44 and the second stop member 45 without play. Axial movements of the rotary piston 4 relative to the shafts 15 are thus blocked. For conveying the medium, conveying spaces, which migrate in the axial direction 31 to the outlet opening 22, form between the thread-shaped profilings 8 as the conveying geometries 7 and the pump section 10 of the housing 9.

The illustrated in Fig. 2 axial seal 26 between the delivery chamber 23 and the security space 25 is shown in Fig. 7 again larger in detail. On the shaft 15, an annular step 48 is formed, so that between the axial end of the rotary piston 4 and the shaft 15, an annular groove 47 is formed. In the annular groove 47, the first stop element 44 is arranged as a stop ring 46 made of metal. Further, in the annular groove 47, a radial inner portion 57 of a first dynamic sealing seat 50 made of metal is arranged. At the first dynamic seal seat 50, a first dynamic mechanical seal 51 is fixed. The first dynamic sealing seat 50 has a radial inner side 58. A first secondary seal 55 as an O-ring seal is used to seal the first dynamic seal seat 50 to the first dynamic mechanical seal 51. On the housing 9, a second static sealing seat 52 is fixed directly or indirectly from metal. A second static mating ring seal 53 is fixed to the second static seal receptacle 52. A second secondary seal 56 as O-Ringdiehtung serves to seal the second static seal seat 52 to the second static mating seal 53. The first dynamic seal seat 50 is indirectly connected to the shaft 15 rotationally fixed positive and / or non-positively connected by means of the stop ring 46, so that the dynamic Dichteaufnahme 50 and the first dynamic mechanical seal 51, the rotational movement of the Shaft 15 and the rotary booster 4 to the rotation axis 38 perform with. The stop ring 46 as the first stop element 44, ie a radial inner side of the stop element 44, rests on a radial outer side 59 of the shaft 15. The radial inner side 58 of the first dynamic sealing seat 50 rests on a radial outer side of the first stop element 44. A sealing gap 54 between the rotating dynamic mechanical seal 51 and the stationary second static mating ring seal 53 serves for the actual sealing of the delivery chamber 23 to the security space 25. The extension of the stop ring 46 in the axial direction 31 is greater than the extension of the ih of the annular groove 47 arranged radial inner portion 57 of the first dynamic sealing seat 50, so that the axial end of the rotary piston 4 rests as an axial stop exclusively on the stop ring 46 and not on the radial inner portion 57 of the first dynamic seal seat 50 with a compressive force, in particular continuous pressure force. The axial extent of the annular groove 47 is thus greater than the axial extent of the radial inner portion 57 of the first dynamic sealing seat 50.

The axial seal 26 is a wearing part that has to be replaced after a certain number of operating hours. A change in the axial position of the rotary piston 4 to each other causes a change in the orientation of the conveyor geometries 7 of the rotary piston 4 to each other. However, since the extension of the stopper ring 46 in the axial direction 31 is greater than the extension of the arranged in the annular groove 47 radial inner portion 57 of the first dynamic seal seat 50 and the replacement of the axial seal 26 stop ring 46 is not replaced, causes the maintenance-related replacement of Axial seal 26 no change in the orientation of the conveyor geometries 7 of the rotary piston 4 to each other. The extent of the stop ring 46 in the axial direction 31 is larger than the extent of the arranged in the annular groove 47 radially inner portion 57, so that even with manufacturing inaccuracies in the production of the portion 57 of the first dynamic seal seat 50 reliably the axial extent of the arranged in the annular groove 47 radial inner portion 57 of the first dynamic seal seat 50 is smaller, the axial extent of the stop ring 46. In a further, not shown embodiment, the first stop member 44 is not formed as a stop ring 46 as a separate component, but in one piece with the rotary piston 4 or the shaft 15th

8 to 12, the necessary devices for producing the conveying element 3 as the rotary piston 4 are shown. A machine tool 65 as a CNC lathe 65 has a chuck 66 as a lathe chuck 66 for clamping a mandrel 78. A tool 67 is used for machining a blank 62 made of metal, in particular stainless steel. A programmable control and / or regulating unit 68 as a computer or computer comprises an electronic data memory 85, in particular an HDD and / or an SSD, and a processor and serves to control and / or regulate the machine tool 65, in particular the movement of the chuck 66 and the tool 67. A sensor 70 as a mechanical scanning element 71 and / or an optical sensor 72 detects a position of a position indicator 63 to the machine tool 65. The at least one sensor 70 thus forms a position detecting means 69 for detecting a relative position of the position indicator 63 and of the blank 62 to the machine tool 65th

The rod-shaped Aufrieahmedorn 78 has a Formformschlussgeometrie 79 as an external toothing, which is identical to the Gegenformschlussgeometrie 40 than the external teeth 41 with 19 teeth on the shaft 15. At an axial end portion of the receiving mandrel 78 is a fixing section 80 for clamping in the chuck 66th formed and the Formformschlussgeometrie 79 at an axial portion of the receiving mandrel 78 is connected to a connecting portion 82 with the Fixing section 80 connected. At the opposite end of the fixing portion 80 of the receiving mandrel 78, an unillustrated external thread is formed for screwing a nut 84 with an internal thread. The nut 84 is used together with a washer 83 for axially fixing the blank 62 or a position gauge 72 between the washer 83 and an axial stop 81 on the mandrel 78th

The position gauge 73 made of metal, in particular steel, has an axial bore 74 and on the axial bore 74 a position-locking geometry 75 is formed as an internal toothing. Furthermore, the position gauge 73 has a first axial end 86 and a second axial end 87. The position locking geometry 75 as an internal toothing is identical to the positive locking geometry 5 as internal toothing 6 of the rotary piston 4 with 19 teeth. On a radial outer side of the position gauge 73, an index 76 is formed as a flat index surface 77. The index 76 is formed in a predetermined rotational position relative to the position-locking geometry 75, so that the position gauge 76 also forms a mechanical data memory 85. When meshing the teeth of the Formformschlussgeometrie 79 of the mandrel 78 with the teeth of Positionsgegenformschlussgeometrie 75 of the position gauge 73, the teeth of Formformschlußgeometrie 79 of the mandrel 78 and teeth of Positionsgegenformschlussgeometrie 75 of the position 73 in a predetermined and known rotational position aligned with each other, so that from Rotational position of the index 76, the rotational position of the position-locking geometry 79 of the mandrel 78 can be determined. The position gauge 73 thus also forms an indirect position detection means 69. For the production of the rotary piston 4, the cylinder jacket-shaped blank 62 with an axial bore 37 is provided. At an axial section of an axial bore 37 of the blank 62, the interlocking geometry 5 is incorporated as an internal toothing 6 with 19 teeth. The 19 teeth are in an identical difference of Rotary position or identical angle aligned with each other. For the position of the conveyor geometry 7 to the positive locking geometry 5 with the 19 teeth, it is thus sufficient to align the rotational position of the conveyor geometry 7 to the form-locking geometry 5 to only one tooth. For an indirect or direct detection of the rotational position of the interlocking geometry 5 to the machine tool 65, it is thus sufficient to detect only the rotational position of a tooth to the machine tool 65 with a position detecting means 69, in particular a sensor 70. The mandrel 78 is inserted with the fixing portion 80 in the chuck 66, so that the mandrel 78 can be rotated relative to the chuck 66 and the machine tool 65, ie the rotational position of the mandrel 78 can be changed to the machine tool 65. Subsequently, the position gauge 73 is pushed with the axial bore 74 on the mandrel 78 until the first axial end 86 of the position gauge 73 rests on the axial stop 81 of the mandrel 78 and the mandrel 78 is disposed in the axial bore 84 of the position gauge 73 and from this protrudes out so that on the protruding part of the receiving mandrel 78, the position gauge 73 with the washer 83 and the nut 84 can be axially fixed to the mandrel 78. The position gauge 73 is thus at a compressive force with the first axial end 86 on the axial stop 81 of the mandrel 78 and with a compressive force is the second axial end 87 of the position gauge 73 on the washer 83 (not shown). The position gauge 73 is thus fixed in the axial direction 31 on the receiving mandrel 78. In this case, the teeth of the internal teeth of the position counter-form geometry 75 of the position gauge 73 mesh with the teeth of the external teeth of the form-locking geometry 79 of the receiving mandrel 78 without play, so that the position gauge 73 and the mandrel 78 are rotatably connected to each other without play. A change of the rotational position of the position gauge 73 to the machine tool 65 causes an identical change in the rotational position of the receiving mandrel 78 of the machine tool and thereby the receiving mandrel 78 to the Chuck 66 twisted. The position gauge 73 is rotated together with the mandrel 78 to this effect manually, so that the flat index surface 77 is aligned horizontally at a horizontal longitudinal axis 39 by a flat spirit level (not shown) is placed on the flat index surface 77. Subsequently, the chuck 66 is fixed, so that the fixing portion 80 of the receiving mandrel 78 rotatably connected to the chuck 66. Deviating from this, the chuck 66 can be rotated as described above with a rotationally fixed fixation of the receiving mandrel 78 on the chuck 66. Thus, the mandrel 78 is in a certain rotational position to the machine tool 65, because the rotational position of the index surface 77 to the position counter-form-locking geometry 75 of Positioning 73 is known and due to the rotationally fixed connection between the position gauge 73 and the mandrel 78 and the rotational position of the receiving mandrel 78 is known to the position gauge 73.

Subsequently, the positioner 73 is removed from the receiving mandrel 78 and the blank 62 is fixed to the receiving mandrel 78 analogously to the positional tool 73 (FIG. 11) without a change in the rotational position of the receiving mandrel 78 relative to the machine tool 65. The interlocking geometry 5 as the internal toothing 6 of FIG Rohlings_ 62 is thus rotatably connected without play with the Formformschlussgeometrie 79 of the mandrel 78, so that the blank 62, in particular the interlocking geometry 5, is in a certain rotational position as a zero rotational position to the machine tool 65 and this particular rotational position is in the coordinate system of the machine tool 65th stored to control the movement of the tool 67 as a zero rotational position. Due to the determined rotational position of the index surface 77 to the position counter-form geometry 75, the position gauge 73 forms a mechanical data memory 85, because a change of the rotational position of the index surface 77 to the position counter-form geometry 75 of the position gauge 73 without changing other parameters, a change of position of the conveyor geometry 7 to the interlocking geometry. 5 would cause. The coordinate system of Machine tool 65 has a Z-axis, which corresponds to the rotation axis 38 of the conveying element 3. An X and Y axis of the coordinate system are aligned perpendicular to the Z axis and the X and Y axis are perpendicular to each other.

Notwithstanding this (not shown), the rotational position of the blank 62, in particular the form-locking geometry 5, can be detected to the machine tool 65 with a sensor 70 without the use of the position gauge 73. For this purpose, at one axial end 64, a mark (not shown) as a position indicator 63 arranged and the rotational position of this mark to the machine tool 65 is detected by the sensor 70. Due to a specific rotational position of the marking relative to the positive-locking geometry 5, the rotational position in the coordinate system of the machine tool 65 for controlling the movement of the tool 67 can thus be stored. Alternatively, the rotational position of the teeth of the interlocking geometry 5, even of only one tooth of the interlocking geometry 5, to the machine tool 65 can also be detected directly with the sensor 70. Subsequently, a mechanical contact with the axial end 64 of the blank 62 is produced with the mechanical scanning element 71 as the mechanical sensor 70 (FIG. 11) and thus the axial position of the blank 62, in particular the form-locking geometry 5, is registered with the machine tool 65. The axial end 64 of the blank 62 thus also forms a position indicating element 63 for the axial position of the interlocking geometry 5 relative to the machine tool 65, because the axial position of the axial end 64 with respect to the interlocking geometry 5 is known.

Thus, the axial position and the rotational position of the interlocking geometry 5 of the blank 52 to the machine tool 65 in the control and / or regulating unit is present. Subsequently, the chuck 66 is set in a rotational movement about a rotation axis 38 at which the axis of rotation of the central longitudinal axis 39 of the Receiving mandrel 78 and the blank 62 corresponds and the axial position of the blank 62 to the machine tool 65 is not changed.

Subsequently, the conveying geometry 7 is incorporated in dependence on the position of the blank 62 detected by the at least one position detecting means 69 to the machine tool 65 and the position stored in the data memory 85 of the feed geometry 7 to be incorporated into the interlocking geometry 5 with the tool 67 by the tool 67 is moved corresponding to the rotating blank 62, so that the conveying geometry 7 is incorporated in the predetermined and stored position to the form-fitting geometry 5 in the blank 62 and the rotary piston 4 is produced and for this purpose 85 corresponding data are stored in the electronic data memory. During the rotational movement of the blank 62, the rotational position of the blank 62, in particular the interlocking geometry 5, is continuously calculated to the machine tool 65 with the control and / or regulating unit 68 and this is possible because with the position detecting means 69 before the start of the rotational movement, the initial rotational position of Blank 62, in particular the form-fitting geometry 5 has been detected to the machine tool 65, so that the movement of the tool 67 for incorporating the conveying geometry 7 is also carried out in dependence on the calculated rotational position.

After complete machining of the conveyor geometry 7 with the tool 67, the geometry of the thread-shaped profiling 8 is checked with the sensor 70, whether this is within the sufficient manufacturing tolerances and then the rotary piston 4 is removed from the mandrel 78. For the production of a further rotary piston 4, the receiving mandrel 78 is again moved with the position gauge 73 in such a rotational position to the machine tool 65 as described above, so that after pushing the further blank 62 onto the receiving mandrel 78 of the blank 62, in particular the positive locking geometry 5 of the blank 62, is in a certain rotational position to the machine tool 65 and this certain rotational position is stored in the coordinate system of the machine tool 65 for controlling the movement of the tool 67 as a zero rotational position or the chuck 66 is moved to the zero rotational position or the known initial rotational position of the chuck 66 with the mandrel 78 and the blank 62 is the control and / or control unit 68 of the machine tool 65 used for the calculation of the movement of the tool 67. Followed by the process steps already described above for the production of the further rotary piston 4 are performed.

In all of the rotary pistons 4 produced by the above-described method, within the manufacturing tolerances, the interlocking geometries 5 and the conveyor geometries 7 are aligned with each other in a substantially identical position. These rotary pistons 4 are rotatably connected in the manufacture of the screw pump 2 with the shafts 15 and then carried out with the adjusting member 49, the synchronization of the delivery geometries 7 of the rotary piston 4 to each other. The rotary pistons 4, ie in particular the thread-shaped profiling 8 as the conveying geometry 7, are subject to mechanical wear and must be replaced after a certain number of operating hours of conveying a certain medium. However, since the previous old worn rotary pistons 4 and the new replacement rotary pistons 4 have been manufactured by the method described above, it is only necessary to replace the previous rotary piston 4 by the new replacement piston 4 without a synchronization of the new replacement piston 4 with the adjusting member 49 is necessary , The new exchange piston 4, the shafts 15 rotatably connected by the 19 teeth of the internal teeth 6 mesh with the 19 teeth of the external teeth 41 of the shaft 15 and only one of the 19 possible rotational positions of each exchange rotary piston 4 to a shaft 15, the correct rotational position for the correct position of the conveyor geometries 7 of the replacement piston 4 to each other. Even with an exchange of the axial seal 26 between the delivery chamber 23 and the security space 25, the axial position of the rotary piston 4 is not changed to each other because of the unchanged first stop element 44, so that even in this exchange no complex synchronization of the rotary piston 4 with the adjusting member 49 is necessary ,

In a further, not shown embodiment for producing the rotary piston 4, a blank 62 is provided with a conveyor geometry 7 analogous to the embodiment described above, then the position of the conveyor geometry 7 is detected with the at least one position detection means 69 to the machine tool 7 and then the interlocking geometry 5 is incorporated with the tool 67 as a function of the position detected by the at least one position detection means 69 and the position stored in the data memory 85, so that the interlocking geometry 5 is incorporated into the blank 62 in the predetermined and stored position relative to the conveyor geometry 7 becomes. In a rotary piston 4 with a radius of 60 mm, the f fenden manufacturing tolerances result in the tangential direction at the radial end of the rotary piston 4: about 1/100 mm manufacturing tolerance in the machining with the machine tool 65, 2/100 mm manufacturing tolerance in the Drehausrichtung the position gauge 73 with the spirit level and a sum of 1/100 mm clearance between the form fit geometry 5, the position counterform geometry 75 and the position form fit geometry 79. This thus gives a total tolerance of 4/100 mm in the tangential direction at the radial end of the rotary piston 4, which an optimal functionality of the screw pump 2 is sufficient. This total tolerance of 4 / 100mm or 0.04 mm corresponds to a rotational position difference or a rotational angle of approximately 0.038 °. Overall, significant advantages are associated with the inventive method for producing the conveying element 3, the inventive method for replacing the at least one conveying element 3 and the screw pump 2 according to the invention. The rotary pistons 4 produced by the method as conveying elements 3 have a substantially identical position of the conveying geometries 7 to the positive locking geometries 5 and vice versa and these rotary pistons 4 were installed and synchronized in the manufacture of the screw pump 2. When replacing the rotary piston 4 and the axial seal 26 for maintenance due to wear, the exchange rotary 4 after installation the substantially same axial position and rotational position to each other as the previously worn rotary piston 4, because due to the unchanged first stop member 44, the exchange rotary 4 axially identical to the previous rotary pistons 4 are aligned with each other on the shafts 15 and due to the identity of the geometry of the previous rotary piston 4 and the exchange rotary piston 4, in particular the identity of the rotational position of the conveyor geometry 7 to the form-fitting geometry 5, the rotary piston 4 on the shafts 15 in one identical rotational position to each other with the shafts 15 are rotatably connected. A lengthy complex synchronization of the exchange rotary piston 4 by means of the adjusting member 49 and an associated disadvantageous time-consuming opening of the gear portion 14 of the housing 9 and hygienic problematic draining oil from the space 24 is thus no longer necessary.

Claims

1. A method for producing a conveying element (3) for a

Two-shaft machine (1) as a positive displacement pump, in particular

Screw pump (2), rotary lobe pump or

Rotary piston pump, with a form-fitting geometry (5) at a first region of the conveying element (3) for applying a torque to the conveying element (3) and with a

Conveying geometry (7) at a second region of the conveying element (3) for conveying a medium by means of the conveying geometry (7), wherein the positive locking geometry (5) and the conveying geometry (7) each form a functional geometry (60, 61), with a machine tool ( 65) with the steps:

- Provide a blank (62) with a first

Functional geometry (60),

- machining a second area of the

Blank with a tool (67), so that on the blank (62) a second functional geometry (61) is incorporated, characterized in that

the position of the first functional geometry (60) with the machine tool (65) is detected with at least one position detection means (69),

- stored in a data memory (85) data relating to a predetermined position of the incorporated second functional geometry (61) to the first functional geometry (60) on the blank (62) and

the second functional geometry (61) is incorporated with the tool (67) as a function of the position detected by the at least one position detection means (69) and the data stored in the data memory (85), so that the second Functional geometry (61) is incorporated in the predetermined and stored position to the first functional geometry (60) in the blank (62).

2. The method according to claim 1, characterized in that the blank (62) with the first functional geometry (60) for

Is provided by a machining of a first portion of the blank (62) with the tool (67) is carried out so that on the blank (62) the first

Function geometry (60) is incorporated.

3. The method according to claim 2, characterized in that first the first functional geometry (60) is machined into the blank (62) and then with the at least one position detecting means (69) the position of the first functional geometry (60) to the machine tool (65 ) is detected.

4. Method according to one or more of the preceding

Claims, characterized in that with the at least one position detecting means (69) to an axial position and / or a rotational position of the first functional geometry (60), in particular by means of at least one of the blank (62) formed Positiohsanzeigeelementes (63) Machine tool (65) is detected.

5. The method according to one or more of the preceding

Claims, characterized in that the position of the first functional geometry (60) to the

Machine tool (65) with a position detecting means (69) as a sensor (70), in particular a movable mechanical scanning member (71) and / or an optical sensor (72) with a laser, directly or indirectly detected.

6. Method according to one or more of the preceding

Claims, characterized in that the position, in particular the rotational position, the first

Functional geometry (60) to the machine tool (65) with a position detecting means (69) as a position gauge (73) is detected and at the position gauge (73) a

Position entgegenformschlussgeometrie (75) is formed and the Positionsgegenformschlussgeometrie (75) in mechanical non-rotatable positive contact with a

Positionsformschlussgeometrie (79) is brought to a mandrel (78).

7. The method according to claim 6, characterized in that the position gauge (73) has an index (76), in particular a

Index area (77), and the index (76) in a given Position is formed to the position Umformschlussgeometrie (75), so that during the mechanical contact between the position counter-form geometry (75) on the position gauge (73) and the Formformschlussgeometrie (79) on the mandrel (78) of the index (76) in a predetermined position the

Positionsformschlussgeometrie (79) on the mandrel (78) is aligned.

8. The method according to claim 7, characterized in that the rotational position of the index (76) and thus also the rotational position of the position-locking geometry (79) with the at least one

Position detecting means (69) is detected during the

mechanical contact between the

Position counterform geometry (75) on the position gauge (73) and the position lock geometry (79) on the arbor (78).

9. The method according to claim 8, characterized in that the index (76) as an index surface (77) and thus also the

Position gauge (73) is moved together with the mandrel (78) in a predetermined rotational position, then the

predetermined rotational position of the index (76) in one

Coordinate system of the machine tool (65) is used and the position gauge (73) is removed from the mandrel (78) and the blank (62) is pushed onto the mandrel (78), so that the first functional geometry (60) on the blank (62 ) is brought into mechanical contact with the position - locking geometry (79) on the receiving mandrel (78) and the rotational position of the first functional geometry (60) of the blank (62) in the

Coordinate system of the machine tool (65) is derived from the rotational position of the index (76).

10. The method according to one or more of the preceding

Claims, characterized in that after the detection of the position of the first functional geometry (60) to the machine tool (65) and during the machining of the second functional geometry (61) in the blank (60) with the tool (67) of the blank (62 ) is fixed in a fixed axial position and / or rotational position to the machine tool (65)

and or

after detecting the position of the first functional geometry (60) to the machine tool (65) and during the machining of the second functional geometry (61) in the blank (62) with the tool (67) the blank (62) in its axial position and or the rotational position is changed to the machine tool (65) and the change of the axial position and / or rotational position of the blank (62) is calculated to the machine tool (65), so that during the machining of the second

Functional geometry (61) into the blank (62) with the tool (67) the position of the first functional geometry (60) of the blank (62) to the machine tool (65) is calculated and in dependence on the calculated position of the first functional geometry (60) of the blank (62) to the machine tool (65) the second

Function geometry (61) with the tool (67) is incorporated. 1.A method according to one or more of the preceding

Claims, characterized in that the first functional geometry (60) is the positive locking geometry (5) and the second functional geometry (61) is the conveying geometry, in particular the conveying element (3) is a rotary piston (4) of a screw pump (2) and the first functional geometry (60 ) as the interlocking geometry (60) is an internal toothing (6) on an axial bore (37) of the rotary piston (4) and the second functional geometry (61) as the conveying geometry (7) is on an outer side of the rotary piston (4) as a thread-shaped profiling (8) trained,

or

the first functional geometry (60) is the conveying geometry (7) and the second functional geometry (61) is the positive locking geometry (5).

12. A method for exchanging at least one previous one

Conveying element (3) at least one twin-shaft machine (1) as a positive displacement pump, in particular screw pump (2), rotary piston pump or rotary piston pump, each with two

Conveying elements (3) and each with two shafts (15), wherein in each case one conveying element (3) with one shaft (15) is rotatably connected and to each a conveying element (3) has a positive connection geometry (5) for applying a torque the conveying element (3) is formed on a shaft (15) by means of a counter-form-fitting geometry (40) and the counter-form-closure geometry (40) is formed on the shaft (15), with the steps:

- provide at least one

Replacement conveyor (3),

Moving out of at least one previous

Conveying element (3) from a delivery chamber (23) and removing the at least one previous conveying element (3) of the at least one twin-shaft machine (1), so that the mechanical contact between the one each

Positive locking geometry (5) of the previous at least one Conveying element (3) and the Gegenformschlussgeometrie (40) of the at least one shaft (15) is repealed,

Inserting the at least one replacement conveying element (3) into the at least one conveying space (23) and fastening the at least one replacement conveying element (3) to the

at least one shaft (15), so that the mechanical contact between each one positive locking geometry (5) of the at least one exchange conveying element (3) and the one each

Counter-form closure geometry (40) of the at least one shaft (15) is produced and the at least one

Replacement conveyor (3) rotatably connected to the at least one shaft (15), characterized in that the at least one Austauschförderelement (3) is provided by the at least one Austauschförderelement (3) produced by a method according to one or more of the preceding claims becomes

and or

in the previous at least one conveying element (3) and in the at least one exchange conveying element (3) each one

Form-fitting geometry (5) and each one conveying geometry (7) in a substantially identical position, in particular rotational position, are aligned with each other.

13. The method according to claim 12, characterized in that after attaching the at least one

Replacement conveyor element (3) on the at least one shaft (15) the rotational position of the two shafts (15) of each a twin-shaft machine remains constant to each other, in particular no adjusting member (49) Change in the rotational position of each two shafts (15) to each other as a synchronization of the two conveying elements (3) on each one

Two-shaft machine (1) is operated,

and or

at a plurality of twin-shaft machines (1) depending on a conveying element (3), preferably two conveying elements (3), is replaced or

become.

14. The method according to claim 12 or 13, characterized in that the previous conveying element (3) and the Austauschförderelement (3) is a rotary piston (4) of a screw pump (2) and the interlocking geometry (5) has an internal toothing (6) on a

Axial bore (37) and the conveying geometry (7) on an outer side of the rotary piston (3) is designed as a thread-shaped profiling (8).

15. Screw pump (2) comprising

a housing (9),

- Two rotary pistons (4) as conveying elements (3), which are arranged within a of a pump section (10) of the housing (3) limited delivery space (23),

- Two mechanically coupled to each other shafts (15), wherein the two rotary pistons (4) rotatably connected to a respective shaft (15) are connected,

- Two axial seals (26) for sealing the delivery chamber (23) to a security space (25), each having a first dynamic sealing receptacle (50) and a second static sealing receptacle (52), wherein the first dynamic sealing receptacle (50) rotatably directly or indirectly with the shaft (15) is connected and the second static sealing seat (52) is attached directly or indirectly to the housing (9) and at the first dynamic A first dynamic mechanical seal (51) is attached to the sealing seat (50) and a second static counter-seal (53) is attached to the second static seal seat (52), characterized in that a radial inner section (57) of the first dynamic seal seat (50) in an annular groove (47), in particular between rotary piston (4) and / or shaft (15) and / or a first stop element (44) is arranged, and the axial extent of the annular groove (47) on the radial inner portion (57) of first dynamic seal seat (50) is greater than the axial extent of the radial inner portion (57) first

Sealing seat (50) in the annular groove (47).