Stator for a pump and method for manufacturing a stator for a pump

Abstract

To provide a stator for a pump improved over the prior art.SOLUTION: A stator for a pump, in particular for a rotary lobe pump or an eccentric screw pump, comprises a base body, which surrounds a pump chamber for a rotor assembly of the pump. The base body includes a support body and a running body. The running body forms a running surface for at least partial contact with the rotor assembly of the pump. The support body and the running body have a common material. A material density of the material of the support body and a material density of the material of the running body are adjusted to be different from one another. The material densities adjusted to be different achieve different elasticity and / or hardness of the material in the support body and the running body. The invention further relates to a method for producing such a stator.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a stator for a pump, particularly for a rotary lobe pump or an eccentric screw pump. The stator according to the present invention comprises a base body that surrounds a pump chamber for a rotor assembly in the pump, and includes a support and a running body that forms a running surface for at least partially contacting the rotor assembly of the pump. Furthermore, the present invention relates to a method for manufacturing a stator for a pump, and a stator for a pump manufactured by such a method.

Background Art

[0002] For example, known stators for eccentric screw pumps are provided with a coating that is partially formed of an elastomer, for example an elastomer, in order to ensure good elastic properties for the rotor operating within the stator during the operation of the pump. Alternatively, solid stators designed with metals or the like are known, and such solid stators have good wear properties during operation, but require high manufacturing precision, have a relatively low pump capacity, or are not completely sealed, for example.

[0003] Regarding the cross-section and / or linear expansion of the elastic material in such a stator, the corresponding rigidity, elasticity, and / or hardness within the stator are the same respectively, and depend only on, for example, the thickness of the selected elastomer and / or specific properties.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem of the present invention is to improve the prior art.

Means for Solving the Problems

[0005] This problem is solved by a stator for a pump, in particular for a rotary lobe pump or an eccentric screw pump, the stator comprising a base, the base enclosing a pump chamber for a rotor assembly in the pump, and including a support and a running body that forms a running surface for at least partially contacting the rotor assembly of the pump, the support and the running body having a common material, the material density of the material in the support and the material density of the material in the running body being adjusted to be different from each other, and thus different elastic and / or hardness are achieved in the material in the support and the running body by the adjusted material densities.

[0006] In this stator design, common materials can be used for the entire stator or for a large portion of it, and nevertheless, by achieving a structural distinction between the running gear and the support, the running gear and the support each have different properties that are important during pump operation.

[0007] This allows the running body to be endowed with properties such as specific wear resistance, and the support structure to be endowed with properties such as high elasticity and resilience against mechanical loads.

[0008] The following explains related terminology.

[0009] A "pump" is a technical device that transports fluids by motion, particularly the relative motion between mechanical parts. In particular, the pump in the context of this invention is a so-called positive displacement pump. Such positive displacement pumps transport fluids by local displacement of the fluid and are designed, for example, as rotary lobe pumps or eccentric screw pumps.

[0010] The term "stator" refers to the fixed part of a pump, to which, for example, the rotor is movably positioned. Such a stator is designed to act in precise conformity with the rotor in a pump, such as a rotary lobe pump, or, for example, in an eccentric screw pump, to ensure elastic contact of the stator with the rotor or rotor assembly during the rotational or eccentric rotational motion of the rotor. Together, the stator and rotor, through their interaction, dynamically move the volume within the pump, thereby fulfilling the role of a "pump," that is, a device for moving fluids, such as a device for pressurizing liquids.

[0011] The term "substrate" refers to the entire mechanical structure of the stator, which provides the structural integrity and corresponding functional aspects of the stator. Such a stator substrate, for example, completely or partially encloses the "pump chamber" when the stator is located within a pump. The pump chamber functions to house a rotor assembly, such as a rotor or a plurality of rotors, in which case the rotor may be the eccentric screw shaft of an eccentric screw pump. Similarly, the rotor or corresponding rotor assembly may refer to the gears of a gear pump, the rotary piston of a rotary lobe pump, or an equivalent technical device in a pump of a corresponding design. The core idea of ​​the present invention in this context is to manufacture at least one of two components, namely the stator and / or one or more corresponding rotors, from a common material and different material densities, thereby obtaining different technical properties. This can be achieved, for example, by a suitable manufacturing method.

[0012] In this context, “support” refers, for example, to a support structure or part of a substrate that substantially mechanically supports forces and functions to absorb deformation, for example, whereas “running body” is specifically designed to act on the rotor assembly and to provide a “running surface” to the rotor. For this purpose, it is of particular importance that the running body and the provided running surface have, for example, greater hardness than the support, or have, for example, better wear characteristics or improved or adapted sliding characteristics to the rotor.

[0013] In this context, “common material” specifically refers to a common substrate or common starting material on which both the stator support and the running body are formed. As the common material, for example, a specific group or type of elastomer may be selected, or a specific metal such as special steel may be selected. As the elastomer, for example, TPE, i.e., thermoplastic elastomer, may be used. Such TPE has the elastic properties of an elastomer, and nevertheless, in contrast to conventional, for example, vulcanized elastomers, it is at least partially softened or meltable by the action of heat. Such TPE is often recyclable and therefore sustainable. It should be noted that the support and / or running body are formed from a common starting material and have the same or equivalent chemical properties after the manufacturing process, but differ in macroscopic or microscopic material density. This difference in material density does not mean a distinction that deviates from the “common material.”

[0014] In this context, the "material density" of each sub-component of the substrate refers to the arrangement of material components in a given volume to achieve different specific gravities and / or different material proportions; therefore, material density is, for example, g / cm³. 3 This can represent not only the weight density but also, for example, the structural density in vol.-%. This structural density can also be achieved, for example, by the non-uniform distribution of material and defects within a given volume.

[0015] In this context, "different adjustments" means that the material density of the material in the support is selected to be lower or higher than, for example, the material density of the material in the running gear, i.e., the running gear has less porosity and / or a greater specific gravity than the support.

[0016] "Elasticity" in this manufactured material refers to the property of absorbing elastic deformation, for example, providing large elongation at break and / or large energy absorption capacity, in which case the material will not be permanently damaged. "Hardness" in this context refers to the material's resistance to local deformation, for example, the material's resistance to mechanical wear due to compression and / or surface damage. In this case, "hard" materials are more wear-resistant than "soft" materials. In the case of elastomers, rebound elasticity is particularly considered as an additional or alternative evaluation criterion, which represents the material's ability to recover from deformation to its original shape after being loaded. This property is especially important when the rotor moves within the stator, because the stator must return as quickly and completely as possible to maintain its sealing performance.

[0017] In order to design the running gear to be particularly wear-resistant to the rotor, the material density of the running gear is greater than that of the support, and therefore the running gear has less elasticity and / or greater hardness and / or adapted rebound elasticity than the support.

[0018] In one embodiment, the support comprises a first support portion, a second support portion, a third support portion, and / or further support portions, wherein the material density of the material in each support portion is adjusted to be different from that of the other support portions, and thus different material densities are achieved, for example, in the material of each support portion compared to that of the other support portions, in particular, the support portions are arranged substantially radially in layers around the pump chamber.

[0019] This design allows for, for example, a gradual mechanical change in the support structure, in which case the boundaries between each support portion may be fluid, and thus, for example, the elastic spectrum and / or hardness spectrum can be achieved, particularly radially with respect to the pump body. However, the corresponding support portions can also be selected as layers, parts, or regions of the support. Such “support portions” are different parts, regions, or sub-regions of the support structure that are geometrically assigned.

[0020] In this case, the adapted material density can also be selected gradually or in stages along the longitudinal axis of the rotor in the eccentric screw pump, thereby counteracting the increase in internal pressure in the pump chamber due to the design principle of the eccentric screw pump. For this purpose, for example, the hardness of the stator can be selected to be lower on the inlet side of the eccentric screw pump where low pressure is applied, and higher towards the outlet side of the eccentric screw pump, thereby counteracting the continuously increasing pressure along the conveying direction and ensuring a seal between the stator and the rotor.

[0021] In this context, "radial around the pump chamber" refers, for example, to the arrangement around the rotor shaft, i.e., the corresponding axis of rotation. It should be noted in this context that "radial" can never be interpreted mathematically precisely and includes technical deviations determined, for example, by the shape of the rotor or other boundary conditions. Therefore, in the case of a rotary lobe pump, the local "radial" arrangement around the pump chamber may also refer to the corresponding sub-region of the pump with respect to each rotating piston.

[0022] Each support and / or particularly each support portion has an internal structure, which has pores, cavities, and / or chambers, as well as webs, lamellae, and / or material bridges, and in particular, different elasticity, adapted spring action, and / or different hardness, different rebound elasticity are achieved in the material of the support and running body by macroscopic material density adjusted by the distribution of pores, cavities, and / or chambers, as well as webs, lamellae, and / or material bridges.

[0023] Such “internal structure” refers, for example, to the geometrically determined or undetermined arrangement of defects intentionally introduced into the material, in which case substantially circular defects, such as pores, geometrically larger “cavities,” or chambers, i.e., intentionally geometrically determined defects, can be introduced. In this case, the mechanical properties of the corresponding material regions, i.e., webs, lamellae, and / or material bridges, are determined by their configuration. In this context, “macroscopic material density” refers, for example, to the material density viewed over the entire support and / or entire support portion, in which case the local material density will inevitably differ, for example, by the high material density in the web and the low material density in the cavity, which can decrease to zero.

[0024] Thus, the stator can be locally provided with, for example, spring elements or elastic support elements.

[0025] In particular, in this case, the internal structure can be configured to be fluidly accessible by a pressurized fluid supply unit or a plurality of pressurized fluid supply units, and the introduction of pressurized fluid into the pores, cavities, and / or chambers of the internal structure through the pressurized fluid supply unit or a plurality of pressurized fluid supply units increases the pressure-inducing force acting on the running body, and / or the discharge of pressurized fluid from the pores, cavities, and / or chambers of the internal structure through the pressurized fluid supply unit or a plurality of pressurized fluid supply units decreases the pressure-inducing force acting on the running body.

[0026] Thereby, for example, the hardness and / or flexibility of the stator can be selectively or partially adapted as needed by adjusting the pressure and / or volume of the pressurized fluid within the internal structure. In particular, this enables the adaptation of the characteristics in the stator to be carried out also by pressure along the conveying direction, so that when the pressure in the pump increases along the conveying direction, the adapted reaction force of the stator against the rotor can also be adjusted.

[0027] The "pressure fluid supply" in this context is, for example, a valve, a pressure connection, or an opening, in particular including a check valve or a controllable valve, which enables the supply of a fluid, for example a gas or a liquid, referred to as "pressurized fluid". Thereby, it is possible to bring about an appropriate behavior of the stator with an appropriately adjusted pressure in the internal structure.

[0028] For this purpose, the "introduction", i.e., the supply of pressurized fluid to increase or maintain the pressure, or the "discharge", i.e., the release of pressurized fluid to decrease or maintain the pressure, is carried out, for example, in response to selectively applied deformations of the stator by the rotor.

[0029] In particular in this case, a control device for introducing and / or discharging pressurized fluid through the pressure fluid supply or the plurality of pressure fluid supplies is assigned to the pressure fluid supply or the plurality of pressure fluid supplies.

[0030] Thereby, the pressure and the pressurized fluid, and thus the appropriate mechanical behavior in the stator, can also be adjusted, for example partially, along the conveying direction.

[0031] In this case, the "control device" refers, for example, to an electronic control device and a valve block controlled by this electronic control device for controlling or adjusting the pressure in response to a pressure sensor.

[0032] In one embodiment, the support, and / or in particular each support part, and / or the running body is manufactured by a prototyping method for forming the material, in particular by an additive process and / or a sintering process.

[0033] In particular, in this case, the prototype method for forming the material can directly generate the corresponding material density distribution in the manufacturing of the stator, for example, by generating a local manufacturing density of the material in the substrate in the case of the addition method, and / or by generating different granular starting materials in the substrate in the case of the sintering method.

[0034] "Material formation method" refers to a process in which a material is formed together with a workpiece from a substrate, base mass, or, for example, powder or granules, particularly by physical action. In this case, for the reasons mentioned above, TPE granules can be used, for example. In this case, "addition method" refers to, for example, "3D printing method," i.e., thermoplastic coating method, laser sintering method, or equivalent process. "Sintering method" refers to a process usually carried out under pressure and high temperature, based on metal powder, in which the material is locally pressed and bonded from individual particles, but the starting material is not completely melted.

[0035] In this particular case, the common material includes additional materials, and the material density is further modified by varying proportions of the additional materials in the support, each support portion, and / or the running body.

[0036] "Further materials" can include, for example, fillers, abrasives, and / or other materials to locally affect the material properties. For example, ceramic powder can be combined with the running gear to combine high density with corresponding wear resistance. Similarly, sliding particles such as graphite particles or TPFE particles (the latter material TPFE is also known as Teflon) can be introduced to reduce sliding friction.

[0037] In one embodiment, the common materials include plastics, in particular elastomers, thermoplastic elastomers, thermosetting plastics, and / or thermoplastics, and / or metals, in particular steel, aluminum, and / or titanium.

[0038] In other embodiments, the problems of the present invention are solved by a method for manufacturing a stator for a pump, particularly as described in any one of the embodiments described above. In this case, the stator comprises a base including a support and a traveling body, the base encloses a pump chamber for a rotor in the pump, the traveling body forms a traveling surface for at least partially contacting the rotor of the pump, the base has different material densities from each other, and this method is - A step of introducing the material substrate into the manufacturing room so that the material substrate is present in the manufacturing room, - A step of processing a material substrate in a manufacturing chamber, wherein the material substrate is converted into a common material through processing, and the processing in the first manufacturing area for manufacturing the support and the processing in the second manufacturing chamber for manufacturing the running body are made different from each other, thereby adjusting the density of the material in the support to be different from the density of the material in the running body, Includes, Therefore, the stator is manufactured so that different elasticity and / or hardness are achieved in the support and running gear by adjusting the material density to be different.

[0039] In this context, “introduction” of material substrates into the manufacturing chamber means providing “material substrates,” i.e., starting filaments for 3D printing and / or sintered powders for sintering methods, into the manufacturing chamber, where the manufacturing chamber refers to, for example, a 3D printer, a sintering mold, or an equivalent assembly.

[0040] In this context, "processing" in the case of 3D printing refers to an action performed on the substrate, such as heating and applying a filament, or irradiating powder or granules with a laser, thereby converting the substrate into a common material, for example, by melting. Similarly, the processing in sintering is carried out by applying pressure and / or heat.

[0041] As a result, as described above, the stator is manufactured, in which case the support and the running gear, in particular, have different material densities.

[0042] In particular, the processing is carried out by prototyping methods, especially addition and / or sintering methods, to form the material. In this case, especially in the common manufacturing process, i.e., the manufacturing of the entire substrate, each manufacturing parameter is adapted so that different material densities are produced. For example, local pressure, laser action, temperature, or the geometric arrangement of the corresponding material regions can be adapted.

[0043] In a further embodiment, the problem of the present invention is solved by a stator for a pump manufactured by the method described above.

[0044] In this context, it should be noted that, in addition to the manufacture of the stator according to the present invention, the rotor of a pump is also equivalently included, for example, if different properties of the material on the rotor of a pump are advantageous for a special design of a pump similar to each embodiment of the illustrated stator.

[0045] In a further embodiment, the problem of the present invention is solved by a pump having a stator and / or rotor according to one of the embodiments described above, in particular a rotary lobe pump and / or an eccentric screw pump, and / or the stator and / or rotor is manufactured by the method described above.

[0046] The present invention will be described in detail below based on embodiments. [Brief explanation of the drawing]

[0047] [Figure 1] This is a schematic side cross-sectional view of a rotary lobe pump. [Figure 2] This is a schematic side cross-sectional view of an eccentric screw pump. [Figure 3] Figure 1 is a schematic cross-sectional view showing the stator of a rotary lobe pump. [Figure 4] Figure 2 is a schematic cross-sectional view showing the stator of an eccentric screw pump. [Modes for carrying out the invention]

[0048] The rotary lobe pump 101 comprises a housing 102 having two housing sections 103 and 104. The internal space 111 is divided by the stator 105 of housing section 103 and the stator 106 of housing section 104, within which rotary pistons 121 and 123 are rotatably positioned along their respective rotational directions 171 and 173. The rotary pistons 121 and 123 are positioned in opposite directions and function within the elliptical housing 102 to pressurize the liquid along the transport direction 181. The corresponding liquid is supplied to the inlet 161, pressurized by the rotary pistons 121 and 123 within the internal space 111, and discharged from the outlet 163.

[0049] The internal structure of stator 105 is the same as that of stator 106 and is shown as an example.

[0050] In this case, while each rotating piston 121, 123 is required to exhibit good wear behavior due to its hard surface, the basic structure of each stator is designed to be elastic, allowing for close contact between each rotating piston. This results in a rotary lobe pump with good sealing properties and, consequently, high efficiency.

[0051] The stator 105 includes a support layer 321 facing the housing portion 103, followed by a support structure 323 and a running layer 325 facing the rotating piston 121 in the direction of the rotating piston 121. The illustrated stator was manufactured by 3D printing, and by this method, the support layer 321 was manufactured to have medium density and medium elasticity. The support structure 323 has intentionally introduced free space 324, thereby obtaining a truss-like structure with high elasticity and enhanced resilience against deformation. In contrast, the running layer 325 is formed using additives to increase density and wear resistance, so the running side 363 facing the rotating piston 121 is designed to be wear-resistant, and the housing side 361 facing the housing portion 103 is elastically deformable. The structure of the stator can be made similar to the structure of the rotating piston, in which case the rotating piston is similar to the stator described above. Therefore, the surface of the rotating piston can also be constructed as an elastic structure similar to the structure of the stator 105, that is, an elastic structure manufactured by 3D printing, in which case the stator is made of, for example, special steel. This allows the rotating piston to have an elastic surface in the axial direction as well, thereby improving the sealing performance in the axial direction.

[0052] The eccentric screw pump 201 has a first housing portion 203 and a pump housing 204. A motor 231 is located outside the housing portion 203, and this motor 231 drives a shaft 235 via a transmission 233. The shaft 235 is morphologically tightly connected to the eccentric screw 237. Alternatively, the connection can be made by a coupling. The eccentric screw 237 is positioned within the pump housing 204 so as to rotate around a rotational direction 271 within an elastic stator 205. In this case, the eccentric screw 237 and stator 205 are configured to meander around their entire circumference, and therefore, as the eccentric screw 237 rotates, the liquid is pressurized from the internal space 211 in the housing portion 203 through the pump chamber 213 in the pump housing 204 along the transport direction 281. In this way, the liquid can be drawn in from the inlet 261 of the housing portion 203 and pressurized along the pump chamber 213 to the outlet 263.

[0053] The stator 205 (see Figure 4 for details) is designed with varying densities and structures across its volume, but is formed from a common material. In this case, the stator 205 is manufactured from an elastomer.

[0054] The stator 205 is provided with a projection 427 on the housing side 461 for fitting tightly into the pump housing 204, and in this case, a support layer 221 having a medium density is formed on the housing side. In the direction of the eccentric screw 237, a support structure 423 is arranged similarly to the support structure 323, and in this case, a free space 424 is also provided. Therefore, the support structure 423 is also formed in a truss shape. On the travel side 463, the layer 425 facing the eccentric screw 237 is designed to be high density and therefore has high wear resistance.

[0055] The stator 205 is manufactured by 3D printing, in which case different densities in each layer and structure are obtained by setting corresponding printing parameters. In the support structure 423 region, a truss-like structure is obtained by omitting material. The stator 205 can have chambers (not shown) separated from each other by the support structure 423 inside it, in which case, for example, a number of chambers are arranged along the transport direction 281 of the eccentric screw pump 201, and compressed air can be loaded into them while they are separated from each other by compressed air connections (not shown), thereby adjusting the hardness of the chambers. Thus, for example, the elastic behavior of the stator 205 can be freely adjusted over a wide range. For example, the hardness of the stator can be gradually increased, thereby adjusting it to respond to the increase in pressure in the eccentric screw pump 201 along the transport direction 281. [Explanation of symbols]

[0056] 101 Rotary lobe pump 102 Housing 103 Housing section 104 Housing section 105 Stator 106 stata 111 Interior space 121 rotation piston 123 rotational piston 161 Entrance 163 Exit 171 Direction of rotation 173 Direction of rotation 181 Conveying direction 201 Eccentric Screw Pump 203 Housing section 204 Pump Housing 205 Stator 211 Interior space 213 Pump Room 231 Motor 233 Transmission device 235 shaft 237 Eccentric Screw 261 Entrance 263 Exit 271 Direction of rotation 281 Conveying direction 321 Supporter layer 323 Support structure 324 Free Space 325 running layers 361 Housing side 363 Driving side 421 Support layer 423 Support structure 424 Free Space 425 running layers 427 Protrusion 461 Housing side 463 Driving side

Claims

1. A stator (105, 106, 205) for a pump (101, 201), comprising a base (321, 323, 325, 421, 423, 425, 427), wherein the base (321, 323, 325, 421, 423, 425, 427) surrounds a pump chamber (111, 213) for a rotor assembly (121, 123, 273) in the pump (101, 201), and includes a support (321, 323, 421, 423) and a traveling body (325, 425) that forms a traveling surface for at least partially contacting the rotor assembly of the pump (101, 201), The supports (321, 323, 421, 423) and the running bodies (325, 425) have a common material including the same material or an elastomer, and the porosity or density of the material in the supports (321, 323, 421, 423) and the porosity or density of the material in the running bodies (325, 425) are adjusted to be different from each other, and so that different elasticity and / or hardness are achieved in the material in the supports (321, 323, 421, 423) and the running bodies (325, 425). A stator characterized in that the support members (321, 323, 421, 423) include a first support member and a second support member, wherein the porosity or density of the material in each support member is adjusted to be different from that of the other support member, and the differently adjusted porosity or density of the material in each support member results in different elasticity and / or hardness being achieved in the material in each support member compared to the other support member, and the support members are arranged radially in layers around the pump chamber (111, 213).

2. A stator according to claim 1, characterized in that the material porosity or material density of the traveling body (325, 425) is greater than that of the support (321, 323, 421, 423).

3. A stator according to claim 1 or 2, wherein the support members (321, 323, 421, 423) and / or each support member portion has an internal structure (323, 324, 423, 424), and the internal structure (323, 324, 423, 424) has pores, cavities (324, 424), and / or chambers, as well as webs, lamellae (323, 424), and / or material bridges.

4. A stator according to claim 3, wherein the internal structure (323, 324, 423, 424) is configured to be fluidly accessible by a pressurized fluid supply unit or a plurality of pressurized fluid supply units, and the pressure-inducing force acting on the running body increases by introducing pressurized fluid into the pores, cavities, and / or chambers of the internal structure (323, 324, 423, 424) through the pressurized fluid supply unit or the plurality of pressurized fluid supply units, and / or the pressure-inducing force acting on the running body decreases by releasing pressurized fluid from the pores, cavities (324, 424), and / or chambers of the internal structure (323, 324, 423, 424) through the pressurized fluid supply unit or the plurality of pressurized fluid supply units.

5. A stator according to claim 4, characterized in that a control device for introducing and / or discharging the pressurized fluid through the pressurized fluid supply unit is assigned to the pressurized fluid supply unit or the plurality of pressurized fluid supply units.

6. A stator according to claim 1 or 2, characterized in that the support bodies (321, 323, 421, 423), and / or each of the support body portions, and / or the running bodies (325, 425) are manufactured by a prototyping method for forming materials.

7. A stator according to claim 1 or 2, characterized in that the common material includes further materials.

8. A stator according to claim 1 or 2, characterized in that the common material includes plastic and / or metal.

9. A method for manufacturing stators (105, 106, 205) for a pump (101, 201) according to claim 1 or 2, wherein the method is - A step of introducing the material substrate into the manufacturing room so that the material substrate is present in the manufacturing room, - A processing step of processing the material substrate in the manufacturing chamber, wherein the material substrate is converted into a common material by the processing, and the processing in the first manufacturing area for manufacturing the support (321, 323, 421, 423) and the processing in the second manufacturing chamber for manufacturing the traveling body (325, 425) are made different from each other, thereby adjusting the material porosity or material density in the support (321, 323, 421, 423) to be different from the material porosity or material density in the traveling body (325, 425), Includes, A method for manufacturing the stators (105, 106, 205) such that different elasticity and / or different hardness are achieved in the materials of the supports (321, 323, 421, 423) and the running bodies (325, 425) by adjusting the material porosity or material density to be different.

10. A method according to claim 9, characterized in that the process includes a method for forming a prototype of a material.

11. Stators (105, 106, 205) for the pump (101, 201) according to claim 1 or 2, manufactured by the method described in claim 9.

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