STATOR FOR AN ECCENTRIC HELICAL PUMP, ECCENTRIC HELICAL PUMP WITH ONE ROTOR AND ONE STATOR, AND METHOD FOR MANUFACTURING A STATOR

Description

1 / 31 STATOR FOR AN ECCENTRIC HELICAL PUMP, ECCENTRIC HELICAL PUMP WITH ONE ROTOR AND ONE STATOR, AND METHOD FOR MANUFACTURING A STATOR FIELD OF THE INVENTION

[001] The present invention relates to stators for eccentric helical pumps, to eccentric helical pumps with such stators and to a method for manufacturing a stator for an eccentric helical pump. STATE OF THE ART

[002] Eccentric helical pumps are known as such. These pumps comprise a stator and a rotor rotating eccentrically within a stator passage. Both the stator and rotor passages are provided with helical surfaces which, interacting with each other during the operation of the eccentric helical pump, form pumping chambers for the medium to be pumped.

[003] Several stator designs for eccentric helical pumps have already been proposed.

[004] For example, in a conventional construction form, the helically wound inner surface of the stator is formed from an elastomer body and is therefore elastically flexible. In this way, with the aid of proper dimensioning of the stator and rotor geometry, it is possible to create a sealing line around each of the pumping chambers. This allows pressure to be maintained during the pumping of a fluid. Furthermore, the elasticity of the stator's inner surface can help improve wear behavior and stator life in such a design, especially when abrasive media containing sand or similar materials are to be conveyed.

[005] In the conventional design mentioned earlier, a tube Petition 870250087153, dated 09 / 26 / 2025, page 43 / 82 2 / 31 of steel is first manufactured and machined separately to produce the stator. An elastomer is injected into this steel tube to form the elastomer body and bond it to the steel tube. This procedure includes, in particular, degreasing and sandblasting the steel tube before elastomer injection, as well as applying an adhesion promoter coating formed with two individual layers as a pre-treatment. The coating, which is constructed with a primer layer and an adhesion promoter layer, serves to create a reliable, strong, and permanent bond between the steel and the elastomer.

[006] In addition, stators have been proposed in which a fixed housing is subsequently detachably arranged around an elastomer body during stator assembly, without the elastomer body and the housing being permanently fixed to each other.

[007] In addition, there are conventional stator construction methods with a solid metal casing, such as steel, cast aluminum, or cast steel, which allow for a uniform wall thickness of the internal elastic material accommodated by the casing.

[008] In addition, pure elastomer stators or stators made entirely of non-elastic plastics, such as PA (polyamide) or PTFE (polytetrafluoroethylene) – so-called solid stators – have already been proposed. Such stators therefore have a hard and rigid inner surface.

[009] The previous conventional procedure for manufacturing a stator for an eccentric helical pump with a support housing and the possibility of maintaining pressure or overcoming back pressure by forming a sealing line is therefore relatively complex and expensive. Petition 870250087153, dated 09 / 26 / 2025, page 44 / 82 3 / 31

[0010] For example, the manufacture of the vulcanized elastomer body is complex, energy-intensive, and expensive. The manufacture of the metal casing and its mechanical processing are also energy-intensive and expensive.

[0011] Furthermore, connecting the elastomer to the metal surface of the housing requires a multi-step and time-consuming pretreatment to achieve good adhesion between the two.

[0012] Furthermore, the stator, as a component of the eccentric helical pump, is generally subject to wear during operation. Therefore, repeated stator replacement may be necessary. The presence of the elastomer body, particularly in its rigid connection with the metal casing constructed as a steel tube, makes recycling a worn stator difficult. Even recycling an elastomer by itself is difficult.

[0013] In this context, it would be desirable to have an improved stator design for an eccentric helical pump that is less complex and more economical to manufacture and, preferably, also more sustainable in terms of the manufacturing process. BRIEF DESCRIPTION OF THE INVENTION

[0014] In this context, it is therefore an object of the present invention to provide a stator for an eccentric helical pump that avoids or mitigates at least one, some or all of the aforementioned disadvantages. Furthermore, a correspondingly improved eccentric helical pump and a correspondingly improved method for manufacturing a stator for an eccentric helical pump should be provided. According to the invention, this objective is achieved by a stator for an eccentric helical pump comprising a stator body having a support housing and an elastic inner lining. Petition 870250087153, dated 09 / 26 / 2025, p. 45 / 82 4 / 31 which the housing is provided with, wherein the housing and the inner lining are each formed of a thermoplastic material. The object of the invention is also achieved by a stator for an eccentric helical pump with a stator body having a support housing and an elastic inner lining of which the housing is provided with, wherein the housing is made of a thermoplastic material, the inner lining is made of a material with elastomer-like properties and the stator body is manufactured in a two-component injection molding process or in a molding process of at least two stages.The objective of the invention is also achieved by a stator for an eccentric helical pump with a stator body having a housing and an elastic inner lining of which the housing is provided internally, the housing having, at least in sections, an external screw-like surface on the outside, which is modified in regions at least by additional demolding surfaces. The objective of the invention is also achieved by an eccentric helical pump with a rotor and a stator as described herein, the stator being designed to cooperate with the rotor and accommodating the rotor at least in sections.The objective of the invention is also achieved by a method for manufacturing a stator for an eccentric helical pump, in particular a stator, as described herein, wherein a stator body is formed with a housing made of a thermoplastic material and the housing is provided with an inner lining made of a material with elastomer-like properties, wherein the stator body is manufactured in a two-component injection molding process or in a molding process of at least two stages.

[0015] Consequently, in a first aspect of the invention, a stator for an eccentric helical pump is proposed, comprising Petition 870250087153, dated 09 / 26 / 2025, page 46 / 82 5 / 31 having a stator body with a support housing and an elastic inner lining with which the housing is provided. The housing and the inner lining are each formed of a thermoplastic material.

[0016] According to a second aspect of the invention, a stator is provided for an eccentric helical pump, comprising a stator body having a support housing and an elastic inner lining with which the housing is provided, wherein the housing is formed with a thermoplastic material, the inner lining is formed with a material with elastomer-like properties and the stator body is manufactured in a two-component injection molding process or in a molding process of at least two stages.

[0017] Furthermore, according to a third aspect of the invention, a stator for an eccentric helical pump is proposed, comprising a stator body having a housing and an elastic inner lining with which the housing is provided on the inside, wherein the housing has, at least in sections, an outer surface resembling a screw, for example, an outer surface resembling a double-threaded screw, which is modified in regions at least by additional demolding surfaces.

[0018] The objective of the invention described above is further achieved according to a fourth aspect of the present invention by a stator for an eccentric helical pump, comprising an internal component or inner lining that is provided for cooperation with a rotor of the eccentric helical pump and is formed with a thermoplastic elastomer or a thermoplastic polyurethane.

[0019] In addition, an eccentric helical pump is provided with a rotor and a stator designed according to the invention. The stator is designed to interact with the rotor and accommodates the rotor by Petition 870250087153, dated 09 / 26 / 2025, page 47 / 82 6 / 31 less in sections.

[0020] Furthermore, the invention provides a method for producing a stator for an eccentric helical pump, in particular for producing a stator designed according to the invention. In the method according to the invention, a stator body is formed with a housing made of a thermoplastic material, and the housing is provided with an inner lining made of a material with elastomer-like properties. The stator body is manufactured in a two-component injection molding process or in a casting process with at least two stages.

[0021] An underlying idea of ​​the invention is that forming both the elastic inner lining and the housing with a thermoplastic material allows for a significant reduction in effort, production time and energy consumption for stator production.

[0022] By forming the elastic inner lining or the internal component with a thermoplastic material, significant energy savings can be achieved compared to the production and vulcanization of an elastomer body. Producing the housing with thermoplastic material instead of metal also allows for a significant reduction in effort and energy consumption. The invention, therefore, makes it possible to significantly reduce the CO2 footprint (the so-called product carbon footprint, or PCF) and manufacture the stator in a more sustainable and resource-efficient way. Furthermore, by forming the housing and inner lining with a thermoplastic material, a strong and reliable adhesive bond between these components can be obtained with little effort.

[0023] For example, according to one idea of ​​the invention, it is even possible to recycle the stator body with the solid composite of the housing and inner lining as a whole as a single-material component when using thermoplastic materials, in particular of the same type Petition 870250087153, dated 09 / 26 / 2025, p. 48 / 82 7 / 31 or family of materials, which are adjusted differently, for example, with respect to one or more mechanical properties of the materials for the casing and the inner lining. For example, the used stator body, preferably after cleaning, can be crushed and reduced to a granulate suitable for further processing. This granulate can then be processed, for example, in a conventional injection molding machine, as fresh plastic granules, or, instead, sold to a materials compound company. In this way, the invention creates a stator for an eccentric helical pump with an elastic inner lining and good performance, which can also be equipped with greater recyclability.

[0024] Advantageously, the proposed design of the thermoplastic housing allows for a comparatively free geometric design, so that, for example, the housing can follow the internal geometry of the stator, for example, in a spiral shape, and thus the thickness of the inner lining wall can be optimized to further improve manufacturability and, for example, can be made more uniform. In addition, the weight of the finished stator component can also be reduced in this way, especially in combination with the thermoplastic inner lining, formed, for example, with a thermoplastic elastomer or thermoplastic polyurethane, which helps to reduce resource consumption in stator production and CO2 emissions associated with its transport, and contributes to easier handling of the stator both during production and by the customer.

[0025] Producing the stator body in a two-component injection molding process or in a molding process of at least two stages allows obtaining a good connection between the housing and the inner lining with little effort, in particular by means of injection molding of the housing and / or the inner lining. Petition 870250087153, dated 09 / 26 / 2025, page 49 / 82 8 / 31 This also contributes to the economical and sustainable production of the stator. Furthermore, such injection molding or casting processes, particularly through injection molding of the housing, allow for easy variation of the housing geometry within wide limits and, in particular, adapting the housing geometry to the internal geometry of the stator with little or no additional cost, with the aforementioned advantages of good production capacity and low component weight.

[0026] The demolding surfaces provided according to one aspect of the invention further facilitate the manufacture of the stator body and contribute to even more economical and cost-effective production. In particular, the demolding surfaces make it possible to manufacture the stator body in a simple construction casting tool, in particular a two-plate non-slip tool. The demolding surfaces may preferably be arranged so as to avoid recesses, which would hinder simple separation of the tool plates in the separation plane without the provision of separate moving tool elements.

[0027] The use of a thermoplastic elastomer or a thermoplastic polyurethane as the thermoplastic material for forming the internal component or inner lining, as provided for in another aspect of the invention, contributes to an economical and sustainable production of the stator, in particular with a reduced CO2 footprint, both on its own and in particular in combination with the housing made of the thermoplastic material. The thermoplastic elastomer or thermoplastic polyurethane can contribute to advantageous recyclability of the stator in combination with a thermoplastic housing.

[0028] The invention can, for example, allow a cost reduction of up to approximately 70 percent compared to the procedure. Petition 870250087153, dated 09 / 26 / 2025, pp. 50 / 82 9 / 31 conventional ment with an elastomer body firmly bonded to a steel casing, and a reduction in CO2 or PCF footprint of up to approximately 70 to 80 percent.

[0029] From the dependent claims and the description with reference to the drawings emerge advantageous embodiments and further developments of the invention.

[0030] In particular, the stator body is manufactured using a two-component injection molding process. This allows for a reliable connection of the housing and inner jacket with little effort, economical and sustainable production, and a complex housing geometry with little additional cost, where the possibility of a complex housing geometry can, in turn, improve manufacturability and reduce stator weight, for example, by making the housing essentially follow the geometry of the inner jacket or component.

[0031] In particular, in one refinement, the housing forms a direct bond with the inner sheath. This simplifies the design and manufacture of the stator body. A complex intermediate layer to improve adhesion between the housing and the inner sheath can be eliminated. A direct bond can be obtained, in particular, by means of the two-component injection molding process or the molding process in at least two stages, in which, in particular, the housing and the inner sheath are injection molded in separate stages of the process.

[0032] According to one embodiment, the inner lining is formed with a substantially uniform wall thickness. This advantageously allows for improved production of the inner lining in an injection molding / casting process, particularly with a thermoplastic material such as a thermoplastic elastomer (TPE) or a thermoplastic polyurethane (TPU). A thickness Petition 870250087153, dated 09 / 26 / 2025, pp. 51 / 82 A uniform, preferably constant, wall thickness of 10 / 31 is advantageous, particularly in the processing of TPE or TPU, especially because it avoids unfavorable material buildup, cavitation, and warping. Furthermore, a uniform wall thickness prevents excessively long cooling times during injection molding of the inner lining, thus enabling a cost-effective manufacturing process.

[0033] In a further development, the housing is connected to the inner lining on the inside by a connecting surface that is at least partially designed as a screw surface and which may, in particular, be designed as a double-threaded screw surface. In this way, a stator body is created in which the housing and the inner lining can be handled together as a whole and the inner lining is reliably mechanically supported on the outside by the housing and provided with pressure stability.

[0034] In particular, the housing has, at least in sections, an outer surface resembling a screw, in particular an outer surface resembling a double-threaded screw. With a housing wound in this manner and therefore with this outer surface, a substantially uniform wall thickness of the inner lining / component, which is advantageous for the manufacturing process, can be achieved and, at the same time, at least a fairly uniform wall thickness of the housing can be made possible. A relatively complex molding of the housing can be obtained relatively easily and cheaply using a thermoplastic material and thus facilitates the production of the inner lining with a uniform wall thickness of a TPE or TPU.

[0035] In one embodiment of the invention, the casing can be re Petition 870250087153, dated 09 / 26 / 2025, pages 52 / 82 11 / 31 externally reinforced by reinforcing ribs, which are preferably formed integrally with the housing. In this way, the mechanical support function of the housing can be further enhanced. The reinforcing ribs can, for example, extend along the body of the stator.

[0036] In one embodiment, an outer contour of the housing can be designed such that the stator body can be manufactured in a two-plate non-slip mold. In this embodiment, the ability to manufacture in a two-plate non-slip mold can be made possible, in particular, by a defined number, shape and size of demolding surfaces provided on the outside of the housing.

[0037] In particular, the screw-shaped outer surface can be modified in some areas, at least by additional demolding surfaces. Such demolding surfaces facilitate economical and cost-effective production of the stator body and help to avoid complicated molds, for example, for injection molding. For example, the demolding surfaces can be arranged in such a way that the stator body can be manufactured in a two-plate tool without slippage and can be demolded without undercuts.

[0038] According to one embodiment, the demolding surfaces are substantially flat or at least partially substantially flat. This allows for demolding surfaces of simple design that can also be advantageously used for other purposes, in particular for engaging mechanical tools or engaging means of transport or retention. However, instead of a flat design of the demolding surfaces, it can be provided that the demolding surfaces are not flat, provided that the shape of the surface Petition 870250087153, dated 09 / 26 / 2025, pp. 53 / 82 12 / 31 demolding surface in the direction of sight towards the parting plane of the forming tool avoid recesses. For example, in another embodiment, the demolding surfaces may be curved and, in particular, formed from mutually parallel generatrices.

[0039] According to a later development, in the area of ​​the demolding surfaces, the wall thickness of the housing is reduced compared to other areas of the housing where it has a screw-shaped outer surface. Since the reduction in housing wall thickness is limited to the demolding surfaces, excessive irregularity in the housing wall thickness is avoided. At the same time, resource consumption for housing production can be limited, resulting in a lightweight and easily manufactured stator.

[0040] In another embodiment, with respect to a central plane of the stator, in which lies a longitudinal axis of the stator, the demolding surfaces are arranged on the outside of the housing on both sides of the central plane. The central plane may, in particular, correspond to a parting plane of a molding tool, such as an injection molding tool. In particular, in a further development, the demolding surfaces may be arranged adjacent to the central plane. In a further development, it may be provided, in particular, that the housing is provided with reinforcing ribs on the outside and that the demolding surfaces are arranged adjacent to at least one of the reinforcing ribs.

[0041] In a further development, two or more demolding surfaces are provided on the outside of the housing on both opposite longitudinal sides of the stator. Petition 870250087153, dated 09 / 26 / 2025, pp. 54 / 82 13 / 31

[0042] According to another embodiment, the demolding surfaces are designed and arranged so that the demolding surfaces, or at least some of them, that are usable - for handling the stator or the housing or both in the manufacture of the stator or - for handling the stator when mounting it on an eccentric helical pump rotor or - for such handling operations in combination. Demolding surfaces can thus be equipped with additional functions and serve as an assembly aid during stator installation in the pump and / or as a handling aid during production. In this case, the demolding surfaces may be particularly suitable or intended as contact surfaces for a handling tool or handling means or for an assembly tool. Handling during production can be automated, for example, with the use of a robot. In addition or alternatively, the demolding surfaces can also serve as an aid for manual assembly with or without tools or manual handling with or without handling equipment.

[0043] In particular, the inner lining is made of a thermoplastic elastomer or a thermoplastic polyurethane. This choice of material for the inner lining allows for more economical and sustainable stator production, in which, in particular, it is also possible to reduce the “product carbon footprint”. The thermoplastic elastomer or thermoplastic polyurethane, when combined with a thermoplastic housing, can also improve the recyclability of the stator.

[0044] In one embodiment, the carcass is formed with a polyamide or a polypropylene or a thermoplastic polyurethane.

[0045] According to further developments, it is expected Petition 870250087153, dated 09 / 26 / 2025, pp. 55 / 82 14 / 31 that the inner lining is made of a thermoplastic elastomer and the shell of polypropylene; or that the inner lining is made of a thermoplastic elastomer and the shell of polyamide; or that the inner lining is made of a thermoplastic polyurethane and the shell of polyamide; or that the inner lining is made of a soft thermoplastic polyurethane and the shell of rigid thermoplastic polyurethane.

[0046] Thus, a variety of exemplary material combinations are possible to create an economical and sustainable stator for an eccentric helical pump, which is adapted to a wide variety of applications, for example, with regard to the medium to be pumped and / or the resistance of the stator in contact with this medium. In addition, the above-mentioned material combinations for the casing and inner lining can significantly improve recyclability.

[0047] In an alternative embodiment of the invention, it can be provided that the inner lining is formed with a cross-linked elastomer and, in particular, that the carcass is formed with a polyamide. For example, when using an injection molding process, such as a two-component injection molding process or a two-stage injection molding process, it is possible to achieve that the inner lining is directly connected to the lining as an elastomer component, thus forming a direct bond without the interposition of one or more adhesion-promoting layers. This, in turn, allows for a simplification of the manufacturing process, avoiding a large number of coating processing steps as well as complex coating preparation to ensure good adhesion.This also advantageously eliminates the need for coating agents for adhesion, allowing the stator body to be manufactured from a straightforward plastic compound. Petition 870250087153, dated 09 / 26 / 2025, pp. 56 / 82 15 / 31 rubber. This can be manufactured independently of the housing geometry, for example, even with a cylindrical housing. The direct plastic and rubber composite can be realized, in particular, using a suitable combination of thermoplastic material for the housing and elastomer for the inner lining, wherein a polyamide is particularly preferred for the housing. Such a design, in turn, allows for the production of a stator in a more economical and sustainable way.

[0048] In an embodiment of the fourth aspect, the stator may further comprise a support housing, wherein the housing is manufactured as a separate component and the internal component is accommodated in the housing, or the housing is connected to the inner lining to form a stator body. Preferably, the housing is formed from a thermoplastic material, wherein the housing is formed in particular from a polyamide or a polypropylene or a thermoplastic polyurethane.

[0049] In realizations of the fourth aspect, it can be provided that - that the inner lining or internal component is made of a thermoplastic elastomer and the housing of polypropylene; or that the inner lining or internal component is made of a thermoplastic elastomer and the housing of polyamide; or that the inner lining or internal component is made of thermoplastic polyurethane and the housing of polyamide; or that - that the inner lining or internal component is made of a soft thermoplastic polyurethane and the housing is made of a rigid thermoplastic polyurethane. Petition 870250087153, dated 09 / 26 / 2025, pp. 57 / 82 16 / 31

[0050] In a further development of the fourth aspect of the invention, the housing may have a screw-like outer surface, at least in sections, and the screw-like outer surface may be modified in regions, at least, by additional demolding surfaces.

[0051] The stators proposed according to the invention can be used, for example, as stators for construction materials, so that, instead, a variety of other applications of the stators proposed according to the invention for the most diverse means of transport, as well as the most diverse eccentric helical pumps and applications are also possible and useful. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The invention will be described in more detail with reference to exemplary embodiments shown in the accompanying drawings.

[0053] The accompanying drawings are included to provide a better understanding of this invention and are incorporated into and form part of this descriptive report. The drawings illustrate embodiments of this invention and, together with the description, serve to explain the principles of the invention. Other embodiments of this invention and many of the intended advantages thereof will be easily understood as they are better understood by reference to the detailed description that follows. The elements of the drawings are not necessarily drawn to the same scale. Equal reference numbers designate similar parts.

[0054] Figure 1 shows an eccentric helical pump according to an embodiment in a schematically simplified side view;

[0055] Figure 2 shows a stator for the eccentric helical pump of Figure 1 according to the embodiment in a side view; Petition 870250087153, dated 09 / 26 / 2025, pp. 58 / 82 17 / 31

[0056] Figure 3 shows the stator of Figure 2 in a cross-sectional view AA, as indicated in Figure 2;

[0057] Figure 4 shows the stator of Figure 2 in a longitudinal sectional view BB, as indicated in Figure 2;

[0058] Figure 5 shows the stator of Figure 2 in an additional DC cross-sectional view, as indicated in Figure 4;

[0059] Figure 6 shows the stator according to the embodiment of Figure 2 in a first perspective view;

[0060] Figure 7 shows a detail D of the perspective view in Figure 6;

[0061] Figure 8 shows another perspective view of the stator according to the embodiment of Figure 2;

[0062] Figure 9 shows a stator for an eccentric helical pump like that in Figure 1 according to another embodiment in a side view;

[0063] Figure 10 shows the stator of Figure 9 in a longitudinal sectional view FF, as indicated in Figure 9;

[0064] Figure 11 shows the stator of Figure 9 in a cross-sectional view EE, as indicated in Figure 9;

[0065] Figure 12 shows the stator of Figure 9 in an additional cross-sectional view GG, as indicated in Figure 10;

[0066] Figure 13 shows the stator of Figure 9 in a first perspective view; and

[0067] Figure 14 shows an additional perspective view of the stator in Figure 9.

[0068] In the figures, similar reference numbers designate similar or functionally similar components, unless otherwise indicated. All directional designations, such as top, bottom, left, right, above, below, horizontal, Petition 870250087153, dated 09 / 26 / 2025, pp. 59 / 82 18 / 31 vertical, rear, front and similar terms are used for explanatory purposes only and are not intended to limit embodiments to the specific arrangements shown in the drawings. DETAILED DESCRIPTION OF THE INVENTION

[0069] Figure 1 shows an eccentric helical pump 1 in a schematically simplified side view. The eccentric helical pump 1 has a stator 3, which in the illustrated embodiment is coupled to a housing 6 on the feed line side. As indicated schematically by arrow 64, the housing 6 mediates the supply of a pumped medium to an inlet side of the stator 3. On the outlet side, the medium to be pumped is discharged in a transport direction indicated in Figure 1 by an arrow 66. However, it is understood that the eccentric helical pump 1 of Figure 1 is shown as an example and that the stator 3, which is described in more detail below, and its variants can be used analogously in other types of eccentric helical pumps 1.

[0070] The stator 3 is an elongated component with a longitudinal direction of the stator L. Along the L direction, the stator 3 has a passage 13 with a helically wound inner surface, not shown in detail in Figure 1. A rotor 4 with a helically wound outer surface is disposed in the passage 13. During the operation of the eccentric helical pump 1, the rotor 4 can rotate eccentrically in the stator 3 passage 13. A drive 10, comprising, for example, an electric motor, is used to drive the rotor 4.

[0071] A stator 3 according to one embodiment, which can be used in the eccentric helical pump 1 of figure 1, is illustrated in figures 2 to 8.

[0072] The stator 3 is formed with a stator body 15. The stator body 15 is in the shape of a tube and has a tubular casing of Petition 870250087153, dated 09 / 26 / 2025, pages 60 / 82 19 / 31 support 19, which is internally provided with an elastic inner lining 21. While the housing 19 has a mechanical support function and is made of a relatively rigid material, the inner lining 21 is made of a material with elastomer-like properties. Along the longitudinal direction L of the stator, the stator body 15 is provided with passage 13, which accommodates the rotor 4. A screw-shaped wound inner surface 91 of the inner lining 21 surrounds passage 13, interacts with the rotor 4 during operation, and is designated in Figures 3 to 5. The inner surface 91 is wound in a manner similar to a double-threaded or helical screw in the embodiment shown in Figures 2 to 8.

[0073] In the embodiment of Figures 2-8, the carcass 19 and the inner lining 21 are each made of a thermoplastic material and are firmly connected to each other directly, without the mediation of a specially applied intermediate layer to improve adhesion. Here, the thermoplastic material of the inner lining 21 is a thermoplastic elastomer, abbreviated TPE, or a thermoplastic polyurethane, abbreviated TPU, while the thermoplastic material of the carcass 19 is in particular a polyamide, abbreviated PA, or a polypropylene, abbreviated PP, or a thermoplastic polyurethane (TPU). By forming the supporting carcass 19 from a thermoplastic plastic material and providing a thermoplastic elastomer or thermoplastic polyurethane for the relatively soft inner lining 21, a firm and reliable adhesion of the carcass 19 and the inner lining 21 is obtained.

[0074] For example, in variants of the embodiment of figures 2-8, the following material combinations are provided for the housing 19 and the inner sheath 21 of the stator body 15: - the casing 19 is made of PP, the inner lining 21 of TPE; or - the casing 19 is made of PA, the inner lining 21 of TPE; or - the casing 19 is made of PA, the inner lining 21 of TPU; or Petition 870250087153, dated 09 / 26 / 2025, pp. 61 / 82 20 / 31 - The casing 19 is made of TPU, the inner lining 21 is also made of TPU.

[0075] In this case, through proper adjustment of the thermoplastics, the casing material 19 is designed to be relatively rigid and hard, while the inner lining material 21 is designed to be relatively soft and elastically flexible. In this way, with proper rotor sizing 4, the rotor 4 can form a sealing line with the inner surface 91 of the inner lining 21 around the transport chambers that form between the inner surface 91 and the rotor 4, through which the eccentric helical pump 1 can accumulate and maintain pressure. Due to its relatively rigid and stiff design, the casing 19 can fulfill its function of mechanical support for the inner lining 21 and allow for pressure stability.

[0076] In one of the exemplary variants mentioned above of the exemplary embodiment, the inner lining 21 is made of a soft thermoplastic polyurethane, and the housing 19 is made of a rigid thermoplastic polyurethane. Thus, such a stator 3 can be considered to be made of a single material, in this variant, TPU. Such a stator 3 can be easily cleaned after its service life, i.e., if the wear of the stator 3 exceeds a tolerable level, it can be recycled as a whole and, for example, shredded and processed into reusable thermoplastic granules. The other combinations of thermoplastic materials mentioned above can also be advantageous in terms of recyclability.

[0077] The inner lining 21 has an inner surface 91 on its inner side and is connected to the housing 19 on its inner side by a substantially screw-like connecting surface 28, similar to the inner surface 91, see Figures 3 and 4. Figures 35 further illustrate that the inner lining 21 has a substantially uniform wall thickness t21, therefore at least in large Petition 870250087153, dated 09 / 26 / 2025, pages 62 / 82 21 / 31 constant part, which is indicated schematically in the figures.

[0078] The housing 19 also has a screw-shaped outer surface 31 on its outer part, which in the illustrated embodiment is again double-threaded. The outer surface 31 essentially follows the connecting surface 28 and the inner surface 91 in parallel. In this way, the housing 19 is also designed with a wall thickness t19 that is essentially uniform and largely constant over large parts of the housing 19. This saves material and therefore resources and, like the uniform wall thickness t21 of the inner lining 21, contributes to good manufacturability.

[0079] Figures 2 and 6 to 8 illustrate the outer surface 31 in various views. The outer surface 31 is divided into several partial surfaces formed as screw-shaped surface pieces, some of which are designated 32, 33, 34, 35. Partial surface 32, viewed in longitudinal section, is a peak surface, partial surface 33 a first inclined and descending flank, partial surface 34 a valley surface, and partial surface 35 a second inclined and ascending flank of one of the threads of the outer contour of the stator body 15. One or both regions of the front end of the stator body 15 may be provided with connection or termination geometries, for example, in the form of stepped cylindrical end sections 16 and / or 17, see Figures 2, 6 and 8, whose outer surfaces are not part of the screw-shaped outer surface 31.

[0080] The outer surface 31, which is designed as a double-threaded screw surface, is modified in a plurality of partial areas by the introduction of surface sections 36 that deviate from the screw surface shape in the embodiment shown in the figures.

[0081] To manufacture stator 3, stator body 15 is manufactured Petition 870250087153, dated 09 / 26 / 2025, pp. 63 / 82 22 / 31 in a two-component injection molding process or in a molding process of at least two stages, which in particular includes two injection molding stages performed separately.

[0082] A two-component injection molding process for the production of the stator body 15 can be advantageously and economically carried out in a two-plate non-slip mold, for example, as a transfer process. The two-plate mold has, for example, two cavities, a first one for molding the inner lining 21 and a second one for molding the housing 19. After injection molding of the inner lining 21, it can be transferred from the first to the second cavity and overmolded with the intended material to form the housing 19, as described above. In a variant of the exemplary embodiment, it can be foreseen that, in a two-component injection molding process, the housing 19 is first injection molded, followed by the inner lining 21, with which the housing 19 is then molded.The use of a two-component injection molding process facilitates obtaining a good and reliable connection between the housing 19 and the inner lining 21.

[0083] Although the material intended for the production of the inner lining 21 has elastic flexibility as described above, a fairly rigid and firm mechanical behavior is desired for the housing 19. To prevent the screw-like outer surface 31, together with the rigid properties of the housing material 19, from hindering the movement of the tool plates of a simple two-plate non-slip tool due to recesses, such recesses, seen in the direction of the central plane M, are eliminated by the surface sections 36. The central plane M forms the parting plane of the forming tool. Thus, the surface sections 36 serve Petition 870250087153, dated 09 / 26 / 2025, pp. 64 / 82 23 / 31 as demolding surfaces, which allows the use of a simple tool to manufacture the housing 19, thus contributing to the reduction of manufacturing costs.

[0084] The wall thickness t19 of the housing 19 is reduced in the area of ​​the demolding surfaces 36 compared to other areas of the housing 19 where it has an unmodified screw-like outer surface 31. This is illustrated by way of example and schematically simplified in Figure 3, in cross-section AA. For example, in the area of ​​the demolding surfaces, the wall thickness t19 can be reduced to approximately 50% of the wall thickness of the housing 19 in unmodified screw-like outer surface areas 31.

[0085] The representation of wall thicknesses t21 and t19 in the figures is intended to illustrate where the actual wall thickness in axially normal cross-sections and in the axially parallel longitudinal section can be distorted due to the shapes of the screw surface.

[0086] To remove the recesses, which would prevent a simple separation of the forming tool, the demolding surfaces 36 – see Figs. 2, 3, 6-8 – are arranged on the outside of the housing 19 on both sides of the central plane M relative to the central plane M of the stator 3, in which the longitudinal axis L of the stator also lies, and each of them is provided adjacent to the central plane M. Here, two or more demolding surfaces 36 are provided on the outside of the housing 19 on two opposite longitudinal sides 45 and 46 of the stator 3. In particular, for each passage of the unmodified screw surface, on the basis of which the outer surface 31 is formed, through the central and separation plane M, a demolding surface 36 is provided on each side of the central plane M.

[0087] The demolding surfaces 36 can, for example, be Petition 870250087153, dated 09 / 26 / 2025, pages 65 / 82 24 / 31 formed with a rounding or curvature, or be substantially flat. In the embodiment of Figures 2 to 8, see, for example, Figures 6 to 8, the demolding surfaces 36 exhibit a slight curvature, but are formed from parallel generatrices perpendicular to the central plane M. Different configurations, flat or non-flat, of the demolding surfaces 36 are conceivable, provided they are suitable to avoid the recess near the central plane M.

[0088] The demolding surfaces 36 on both longitudinal sides 45 and 46 are also designed and arranged so that the demolding surfaces 36 or at least some of them can be used to handle the stator 3 or the stator body 15 or the housing 19 or both during the manufacture of the stator 3 and / or to handle the stator 3 during its assembly on the rotor 4.For example, the demolding surfaces 36 or some of them can facilitate the removal of the finished stator body 15 from the molding tool after injection molding of the housing 19.

[0089] For example, the demolding surfaces 36 can serve as engagement surfaces for an assembly tool or handling tool or means. In Figure 3, a tool or means 55 for assembly or handling is shown schematically and by way of example only. The demolding surfaces 36 can thus, for example, be well suited for automatically removing the finished injection-molded stator body 15 from the molding tool, for example, using a robot and a gripper as handling means 55. Furthermore, the demolding surfaces 36 can simplify the screwing of the stator 3 onto the rotor 4 at the customer's site, manually or using the assembly tool 55. A flat or at least partially flat design of the demolding surfaces 36 may be convenient for their use for assembly and / or handling as described, although this is not mandatory and surfaces Petition 870250087153, dated 09 / 26 / 2025, pp. 66 / 82 25 / 31 demolding 36 with different shapes, for example, slightly curved, can also be equally convenient to facilitate assembly and / or handling.

[0090] Although it is preferable to provide the demolding surfaces 36 as explained above to allow simple and economical production, in another variant of the embodiment described above with reference to Figures 2 to 8, the demolding surfaces 36 may be omitted and a more complex forming tool may be used.

[0091] In a further variant of the embodiment described above with reference to Figures 2 to 8, the stator body 15 may be manufactured in a two-stage casting process instead of a two-component injection molding process. In this case, the housing 19 is first manufactured separately from the selected material by injection molding and the finished housings 19 are subsequently injected with the inner lining 21, the inner lining 21 then being formed into the housing 19 by injection molding from the selected thermoplastic material, in particular TPE or TPU. Alternatively, in another variant of the embodiment, the inner lining 21 may first be manufactured separately by injection molding from the selected thermoplastic material, in particular TPE or TPU, and the finished inner linings 21 may subsequently be supplied with the housing 19 in a separate injection molding operation.

[0092] In the above embodiments, the housing 19 preferably forms a direct connection with the inner lining 21, in which a specially applied adhesion promoter layer between the housing 19 and the inner lining 21 is not required.

[0093] In other variants of the explained concretization form Petition 870250087153, dated 09 / 26 / 2025, pp. 67 / 82 26 / 31 above with reference to Figures 1-8, it can be foreseen that the inner lining 21, instead of being permanently and adhesively connected to the housing 19, is detachably disposed within a housing. For this purpose, an inner component 21 is manufactured, designed as described above for the inner lining 21, but used as a separate component. The material used to form the inner component is a thermoplastic elastomer or a thermoplastic polyurethane, from which the inner component is manufactured by means of an injection molding process. The resulting inner component is then housed as a separate part in a supporting housing without adhesive connection to it, the housing being made of a thermoplastic material, as described above, but also of a metal. For example, such a housing in this variant can be geometrically designed essentially as described in Figures 1 to 8.It can be anticipated that, in this variant, the casing can be opened or disassembled to insert the internal component made of TPE or TPU into the casing.

[0094] In another embodiment of the invention, it can be provided that the housing 19 is formed of a thermoplastic, preferably a relatively hard plastic material, as in the embodiments explained above, while the inner lining 21 is formed of a cross-linked elastomer, unlike the embodiments above. For the housing 19, a suitable polyamide can be selected as the thermoplastic material, for example, a polyamide available under the name VESTAMID® from Evonik Industries. The inner lining 21 is therefore formed of a rubber material, for example, a synthetic rubber. In this embodiment, the housing 19 is first injection molded from the thermoplastic material selected for it, and then the inner lining 21 is introduced into the housing 19 by injection molding of the elastomer. In this way, the inner lining 21 is formed during injection and can adhere to the housing 19 during cross-linking. Petition 870250087153, dated 09 / 26 / 2025, pages 68 / 82 27 / 31 or elastomer vulcanization. Thus, in this embodiment of the invention, the stator body is also manufactured using a two-component injection molding process or a two-stage molding process. The composition of the thermoplastic material of the housing 19 is selected so that the inner lining 21 forms a good bond with the support housing 19, so that a direct plastic-rubber bond can be achieved and a separately applied adhesion promoter layer can be omitted.

[0095] In the case of the embodiment described above with a stator body 15 formed from a direct plastic-rubber composite, the geometry of the housing 19 and the inner lining 21 can be designed as described above with reference to Figures 1-8, therefore analogous to the embodiment with a thermoplastic inner lining 21, for example, made of TPE or TPU. In variants, however, in the case of the direct plastic-rubber composite, it can be provided that the thermoplastic sheath 19 is formed as a substantially cylindrical tube with a cylindrical connecting surface to the inner lining. In this case, the wall thickness of the elastomeric inner lining varies.

[0096] Figures 9 to 14 show a stator 103 according to another embodiment. Except for the differences described below, stator 103 is designed like stator 3 illustrated in Figures 2 to 8 and can be used in an exemplary eccentric helical pump 1, as illustrated in Figure 1, essentially analogously to stator 3. Elements and characteristics of stator 103 that correspond to those of stator 3 are provided with reference numbers that are formed from the reference numbers of the characteristics of stator 3 and adding 100 to them.

[0097] Stator 103 differs in particular from stator 3 because a housing 119 of stator 103, formed of a thermoplastic material, Petition 870250087153, dated 09 / 26 / 2025, pp. 69 / 82 28 / 31, made of a polyamide, polypropylene, or rigid TPU, is provided with external reinforcing ribs 178, 179, 180, and 181, which extend substantially parallel to the longitudinal axis L of the stator in the stator body 115 and therefore in the stator 103. The reinforcing ribs 178-181 stiffen the stator 103 against bending about a transverse axis and increase its resistance against mechanical forces along the longitudinal axis of the stator L.

[0098] Reinforcing ribs 178-181 are manufactured in one piece with the housing 119 during the manufacture of the housing 119, in particular by means of injection molding over an inner lining 121 or, for example, during the injection molding of the housing 119 before the injection molding of the same with the inner lining 121, and are therefore formed from the same thermoplastic material as the housing 119.

[0099] The reinforcing rib 181 is additionally formed with a radially extending recess 185, in particular a round blind hole, which can be used for fastening or connection purposes, for example, by means of a screw. The recess 185 is surrounded by a hollow cylindrical enlargement of the rib 181, which is also laterally stiffened in a direction transverse to a main extension direction of the reinforcing rib 181 by additional transverse ribs 182, in order to be able to divert any load inputs at the location of the recess 185 to the housing 119.

[00100] The four reinforcing ribs 178-181 are arranged in the cross-section of the stator 103 at intervals of substantially 90 degrees around the longitudinal axis L of the stator and extend radially outward.

[00101] Although four reinforcing ribs 178-181 are shown for the example in Figures 9-14, it is understood that more or fewer reinforcing ribs may be provided in variants of this form of Petition 870250087153, dated 09 / 26 / 2025, pp. 70 / 82 29 / 31 implementation. For example, only two reinforcing ribs arranged approximately 180 degrees opposite each other could be provided, or more than four reinforcing ribs could be provided, such as six or eight, which are arranged in particular evenly distributed over the circumference of the stator.

[00102] The inner lining 121 of the stator 103 according to the embodiment of Figures 9-14 is injection molded from a thermoplastic material with elastomer-like properties, preferably a TPE or a TPU.

[00103] In the embodiment of Figures 9-14, the central plane M, which coincides with a parting plane of a molding tool, in particular an injection molding tool, for a stator body 115 formed with the housing 119 and the inner sheath 121, is centrally located within each of the reinforcing ribs 180 and 178 arranged 180 degrees opposite each other, see Figures 13, 9 and 11.

[00104] The demolding surfaces 136 are arranged, except for the rib areas 180, 178, on an outer surface 131 of the housing 119 in a manner analogous to the demolding surfaces 36, in order to eliminate recesses in the direction of sight towards the central plane and the parting plane M. Except for the demolding surfaces 136, the reinforcing rib areas 178-182 and the recess 185, the outer surface 131, analogous to the embodiment of Figure 2-8, is essentially designed as a screw surface and, in Figure 9-14, again as a double-threaded screw surface. The screw surface on which the outer surface 131 is based is therefore modified by both the ribs 178-182 and the demolding surfaces 136.

[00105] The cross-sectional views in Figures 10 and 11 also make it clear that the wall thickness t121 of the housing 121, as in the form of Petition 870250087153, dated 09 / 26 / 2025, pp. 71 / 82 30 / 31 embodiment of Figures 2 to 8, is essentially constant, which improves the manufacturability of the inner lining 121, in particular of TPE or TPU, and that the wall thickness t119 in the region of the demolding surfaces 136 is reduced compared to other regions of the housing 119, in which its outer surface 131 is designed as a screw surface, essentially analogous to that described above for the wall thickness t19.

[00106] The stator 103 can be modified into variants thereof, as described above for variants of stator 3, and can, in addition, in another embodiment, alternatively be formed with a direct plastic-rubber compound, as also described above for a variant of stator 3.

[00107] Although the invention has been fully described above with reference to preferred embodiments, it is not limited to them but can be modified in many ways. LIST OF REFERENCE NUMBERS Eccentric helical pump, 103 Stator Rotor Carcass Actuation, 113 Passage (Stator) 15, 115 Stator body 16, 116 Final section (stator body) 17, 117 Final section (stator body) 19, 119 Carcass 21, 121 Internal lining or internal component 28, 128 Connection surface 31, 131 External surface (casing) Petition 870250087153, dated 09 / 26 / 2025, pp. 72 / 82 31 / 31 32, 132 Part of the outer surface (casing) 33, 133 Part of the outer surface (casing) 34, 134 Part of the outer surface (casing) 35, 135 Part of the outer surface (casing) 36, 136 Mold release surface 45, 145 First long side (stator) 46, 146 Second long side (stator) Handling or assembly tool Progress of the transported material Transportation direction 178, 179 Reinforcing rib 180, 181 Reinforcing rib 182 Transverse rib 185 Recess 91, 191 Internal surface (stator) t19, t119 Wall thickness (shell) t21, t121 Wall thickness (inner lining) L Longitudinal axis of the stator (stator) M Central plane (stator) Petition 870250087153, dated 09 / 26 / 2025, pp. 73 / 82

Claims

1 / 5 CLAIMS 1. Stator (3; 103) for an eccentric helical pump (1), characterized in that it comprises a stator body (15; 115) having a support housing (19; 119) and an elastic inner lining (21; 121) of which the housing (19; 119) is provided, wherein the housing (19; 119) and the inner lining (21; 121) are each formed of a thermoplastic material.

2. Stator for eccentric helical pump, according to claim 1, characterized in that the stator body (15; 115) is manufactured in a two-component injection molding process.

3. Stator (3; 103) for an eccentric helical pump (1), with a stator body (15; 115) having a support housing (19; 119) and an elastic inner lining (21; 121) of which the housing (19; 119) is provided, characterized in that the housing (19; 119) is made of a thermoplastic material, the inner lining (21; 121) is made of a material with elastomer-like properties and the stator body (15; 115) is manufactured in a two-component injection molding process or in a molding process of at least two stages.

4. Stator for eccentric helical pump, according to any of the preceding claims, characterized in that the housing (19; 119) forms a direct connection with the inner lining (21; 121).

5. Stator for an eccentric helical pump, according to any of the preceding claims, characterized in that the inner lining (21; 121) is formed with a substantially uniform wall thickness (t21; t121).

6. Stator for an eccentric helical pump, according to any of the preceding claims, characterized by Petition 870250087153, dated 09 / 26 / 2025, page 74 / 82 2 / 5 the fact that the housing (19; 119) is internally connected to the inner lining (21; 121) on a connecting surface (28; 128) that is at least partially designed as a screw surface, in particular as a double-threaded screw surface.

7. Stator for an eccentric helical pump, according to any of the preceding claims, characterized in that the housing (19; 119) has, at least in sections, an external surface resembling a screw (31; 131), in particular an external surface resembling a double-threaded screw (31; 131).

8. Stator for an eccentric helical pump, according to claim 7, characterized in that the screw-shaped outer surface (31; 131) is modified in regions at least by additional demolding surfaces (36; 136).

9. Stator (3; 103) for an eccentric helical pump, with a stator body (15; 115) having a casing (19; 119) and an elastic inner lining (21; 121) with which the casing (19; 119) is provided internally, characterized in that the casing (19; 119) has, at least in sections, an external screw-like surface (31; 131) on the outside, which is modified in regions at least by additional demolding surfaces (36; 136).

10. Stator for an eccentric helical pump, according to any one of claims 8 or 9, characterized in that the demolding surfaces (36; 136) are each substantially flat or at least partially substantially flat or that the demolding surfaces (36; 136) are each curved and, in particular, are formed from mutually parallel generatrices.

11. Stator for an eccentric helical pump, according to any one of claims 8 to 10, characterized in that Petition 870250087153, dated 09 / 26 / 2025, page 75 / 82 3 / 5 that in the region of the demolding surfaces (36; 136) a wall thickness (t19; t119) of the casing (19; 119) is reduced compared with other regions of the casing (19; 119) in which it has the screw-shaped outer surface (31; 131).

12. Stator for an eccentric helical pump, according to any one of claims 8 to 11, characterized in that, with respect to a central plane (M) of the stator (3; 103), on which a longitudinal axis of the stator (L) thereof lies, the demolding surfaces (36; 136) are disposed on the outside of the casing (19; 119) on both sides of the central plane (M) and, in particular, that the demolding surfaces (36) are disposed adjacent to the central plane (M) or the casing (119) is provided on the outside with reinforcing ribs (178-181) and the demolding surfaces (136) are disposed adjacent to at least one of the reinforcing ribs (178, 180).

13. Stator for an eccentric helical pump, according to any one of claims 8 to 12, characterized in that two or more demolding surfaces (36; 136) are provided on the outside of the housing (19; 119) on both opposite longitudinal sides (45, 46; 145, 146) of the stator (3; 103).

14. Stator for an eccentric helical pump, according to any one of claims 8 to 13, characterized in that the demolding surfaces (36; 136) are designed and arranged in such a way that the demolding surfaces (36; 136) or at least some of them can be used to handle the stator (3; 103) or the housing (19; 119) or both during the manufacture of the stator (3; 103) or to handle the stator (3; 103) during its assembly in a rotor (4) of the eccentric helical pump (1) or for such handling operations in combination, in particular are suitable or provided as engagement surfaces for a handling tool (55) Petition 870250087153, dated 26 / 09 / 2025, p. 76 / 82 4 / 5 or an assembly tool (55).

15. Stator for eccentric helical pump, according to any of the preceding claims, characterized in that the inner lining (21; 121) is made of a thermoplastic elastomer or a thermoplastic polyurethane.

16. Stator for eccentric helical pump, according to any of the preceding claims, characterized in that the housing (19; 119) is made of a polyamide or a polypropylene or a thermoplastic polyurethane.

17. Stator for eccentric helical pump, according to any of the preceding claims, characterized in that the inner lining (21; 121) is made of a thermoplastic elastomer and the housing (19; 119) is made of polypropylene; or that the inner lining (21; 121) is made of a thermoplastic elastomer and the housing (19; 119) is made of polyamide; or that the inner lining (21; 121) is made of thermoplastic polyurethane and the housing (19; 119) is made of polyamide; or that the inner lining (21; 121) is made of soft thermoplastic polyurethane and the housing (19; 119) is made of rigid thermoplastic polyurethane.

18. Stator for an eccentric helical pump, according to claim 4 or any of claims 5 to 14 in conjunction with claim 4, characterized in that the inner lining (21; 121) is made of a cross-linked elastomer and in particular that the housing (19; 119) is made of a polyamide.

19. Eccentric helical pump (1) with a rotor (4) and a stator (3; 103), as defined in any of the preceding claims, characterized in that the stator (3; 103) is designed to cooperate with the rotor (4) and accommodates the rotor (4) at least in sections.

20. Method for manufacturing a stator (3; 103) for an eccentric helical pump (1), in particular a stator (3; 103), as defined in any of claims 1 to 18, characterized in that a stator body (15; 115) of the stator (3; 103) is formed with a housing (19; 119) made of a thermoplastic material and the housing (19; 119) is provided with an inner lining (21; 121) made of a material with elastomer-like properties, wherein the stator body (15; 115) is manufactured in a two-component injection molding process or in a molding process of at least two stages. Petition 870250087153, dated 09 / 26 / 2025, pp. 78 / 82

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