Method and mold for manufacturing an impeller

Abstract

A method for manufacturing an impeller is provided. The method comprises providing a mold comprising a core and a fiber element arranged on the core, wherein the core has a vacuum line network inside, the vacuum line network comprising a plurality of branched and interconnected vacuum lines in fluid communication with a main vacuum line; and feeding a matrix material into a space defined at least by the core by generating a negative pressure in the vacuum line network. Also provided is a core having a vacuum line network inside, the vacuum line network comprising a plurality of branched and interconnected vacuum lines, and a mold comprising the core.

Description

Technical Field

[0001] This disclosure generally relates to methods for manufacturing composite material impellers. In particular, but not exclusively, this disclosure relates to vacuum-assisted methods for manufacturing composite material impellers and molds that can be used in said methods. Background Technology

[0002] This section provides useful background information, but does not acknowledge that any techniques described herein represent prior art.

[0003] The advantages of composite impellers include, for example, their durability and light weight compared to metal impellers. Traditionally, composite impellers are manufactured by separately producing the blades and other impeller components, then assembling and connecting them together. However, the joints or seams between the assembled components create weak points in the structure. Furthermore, these methods are labor-intensive and time-consuming.

[0004] Traditional methods for manufacturing composite impellers typically require casting molds or sealing molds. In the production of small batches or even single impellers, creating casting molds for each impeller model is both time-consuming and resource-intensive.

[0005] Therefore, an improved method is needed to manufacture high-quality composite impellers. Summary of the Invention

[0006] The appended claims define the scope of protection. Any examples and technical descriptions of devices, products, and / or methods not included in the scope of the claims in the specification and / or drawings are not presented as embodiments of the invention, but rather as examples to aid in understanding the invention.

[0007] The objective is to provide an improved method for manufacturing high-quality composite impellers, or at least an alternative to existing technologies. In particular, the objective is to provide an improved method for manufacturing high-quality large composite impellers.

[0008] According to a first exemplary aspect, a method for manufacturing an impeller is provided, the method comprising: Provide molds, including: The core, wherein the core contains a vacuum tube network, the vacuum tube network comprising multiple branching and interconnected vacuum tubes in fluid communication with the main vacuum tube, and Fiber elements arranged on the core; and By generating negative pressure in the vacuum pipeline network, the matrix material is supplied to the space defined at least by the core.

[0009] In some implementations, multiple branched and interconnected vacuum lines include branched vacuum lines at different heights within the core.

[0010] In some embodiments, the core is at least partially formed of more than one layer having a corresponding thickness, and multiple branching and interconnected vacuum tube routes are formed by cavities in each layer. In some embodiments, the layers are stacked on top of each other.

[0011] In some implementations, the vacuum tubing network has multiple openings on the surface of the core.

[0012] In some implementations, the matrix material is supplied without applying pressure higher than atmospheric pressure.

[0013] In some implementations, the mold is a non-sealed mold.

[0014] In some embodiments, the matrix material is supplied to the space defined at least by the core via one or more feed lines located at least partially within the core. In some embodiments, the matrix material is supplied to the space defined at least by the core via a network of feed lines comprising a plurality of branching and interconnected feed lines arranged within the core.

[0015] In some embodiments, the diameter of one or more feed lines located at least partially within the core is larger than the diameter of a plurality of branched and interconnected vacuum lines within the core. In some embodiments, the diameter of the plurality of branched and interconnected feed lines within the core is larger than the diameter of the plurality of branched and interconnected vacuum lines within the core.

[0016] In some embodiments, providing a mold includes: Provide cores, and Fiber elements are laid on the core.

[0017] In some embodiments, the method includes curing the matrix material after it has been supplied to the mold, preferably by heating.

[0018] In some embodiments, the method includes removing the mold after supplying and optionally curing the base material. In some embodiments, the method includes removing the core after supplying and optionally curing the base material, preferably by machining. In some embodiments, core removal is performed without melting the core. In some embodiments, the core is a breakable core. Core removal may include breaking the core (into smaller fragments). The core may be a disposable core, i.e., it is used or can be used to manufacture an impeller.

[0019] In some embodiments, the core is a machinable core, preferably a machinable core formed of a polymer, and more preferably a core with a density of at least 30 kg / m³. 3The polymer foam is formed into a machinable core, wherein the polymer foam is preferably selected from one or more of the following: epoxy resin, phenolic resin, polypropylene, polyurethane, polyvinyl chloride (PVC), acrylonitrile-butadiene-styrene copolymer (ABS) and / or cellulose acetate.

[0020] In some implementations, the fibrous element is formed of carbon fiber.

[0021] In some embodiments, the matrix material comprises one or more thermosetting polymers, preferably selected from one or more of the following: epoxy resins, phenolic polymers, polyesters, vinyl esters, amines, furan resins, polyimide (PI), bismaleimide (BMI), cyanate esters (CE), phthalonitrile and / or benzoxazine.

[0022] According to a second exemplary aspect, a method for manufacturing an impeller is provided, the method comprising: Provide a mold, the mold comprising The core, wherein the core contains a vacuum tube network, the vacuum tube network comprising multiple branching and interconnected vacuum tubes that are in fluid communication with the main vacuum tube, and Prepreg fiber elements arranged on the core; and A negative pressure is generated in the vacuum tubing network to press (at least some) of the prepreg fiber elements onto the core.

[0023] According to a third exemplary aspect, a core is provided, the core including a vacuum tube network, the vacuum tube network including multiple branched and interconnected vacuum tubes.

[0024] In some implementations, multiple branched and interconnected vacuum lines include branched vacuum lines at different heights within the core.

[0025] In some embodiments, the core is formed at least in part by more than one layer having a corresponding thickness, and multiple interconnected branch vacuum tubes are formed by cavities in the layers.

[0026] In some implementations, the vacuum tubing network has multiple openings on the surface of the core.

[0027] In some embodiments, the core includes one or more feed lines at least partially disposed within the core. In some embodiments, the core includes a feed line network comprising a plurality of branching and interconnected feed lines disposed within the core.

[0028] In some embodiments, the diameter of one or more feed lines, at least partially arranged within the core, is larger than the diameter of a plurality of branched and interconnected vacuum lines within the core. In some embodiments, the diameter of the plurality of branched and interconnected feed lines within the core is larger than the diameter of the plurality of branched and interconnected vacuum lines within the core.

[0029] According to another exemplary aspect, a mold for manufacturing an impeller is provided, the mold including a core according to a third exemplary aspect.

[0030] According to yet another exemplary aspect, a method for manufacturing an impeller by vacuum-assisted resin transfer molding (VARTM) is provided, the method comprising manufacturing the impeller in a single piece and / or a single resin curing step without using a housing and / or sealing mold.

[0031] The foregoing has described various non-limiting exemplary aspects and implementations. The foregoing implementations are merely illustrative of selected aspects or steps that may be used in different implementations. Some implementations may be presented with reference only to certain exemplary aspects. It should be understood that corresponding implementations may also be applied to other exemplary aspects. Attached Figure Description

[0032] Some exemplary embodiments will be described with reference to the accompanying drawings, in which: Figure 1 An example of an impeller is shown schematically; Figure 2 The core and its internal vacuum tubing network are schematically illustrated according to an exemplary embodiment. Figure 3 An assembly mold according to an exemplary embodiment is schematically shown; and Figure 4 A flowchart of a method according to an exemplary embodiment is shown. Detailed Implementation

[0033] In the following description, the same reference numerals denote the same elements or steps.

[0034] As used herein, composite material or composite material preferably refers to fiber-reinforced composite material comprising fibers and matrix materials or substantially composed of fibers and matrix materials. In particular, it relates to fiber-reinforced polymer (FRP) composite materials, and preferably carbon fiber reinforced polymer (CFRP) composite materials.

[0035] As used herein, fluid can refer to liquid or gas, or a combination thereof. In the context of this disclosure, fluid may contain small or trace amounts of solids, such as solid particles, typically as impurities.

[0036] In the context of this disclosure, an impeller eye refers to an opening or empty space, typically located in the central region of the impeller, used to mount the impeller onto, for example, a spindle or shaft.

[0037] An impeller can be defined as a driven rotor used to increase fluid pressure and / or flow rate. Typically, fluid flow in an impeller is axial inflow and radial outflow. Impellers can be used, for example, in pumps and / or compressors, particularly to generate suction in pumps or compressors.

[0038] Impellers can sometimes be classified into open impellers, semi-closed impellers, and closed impellers based on their structure. A closed impeller typically includes a back wall, a front wall, and blades positioned around the impeller inlet. The blades are arranged between the back and front walls, ensuring that both walls are in contact with the blades. A semi-closed impeller, in addition to the blades arranged around the impeller inlet, usually includes a back wall but not a front wall. The blades are typically arranged on the back wall and protrude or extend from it. An open impeller typically includes blades arranged around the impeller inlet but excludes neither a back wall nor a front wall.

[0039] Figure 1 A non-limiting example of a closed impeller 100 is illustrated schematically. Those skilled in the art will understand that the size and design of a particular impeller can vary, for example, depending on its intended use. For instance, the number and shape of the blades can vary. Figure 1 The impeller includes a rear wall 110 and a front wall 120, and a plurality of blades 130 arranged between the rear wall 110 and the front wall 120. A gap is provided between each pair of adjacent blades 130. An impeller inlet 140 for mounting the impeller to a spindle or shaft is provided in the central region of the impeller 100. Fastening holes 150 for fastening devices are typically provided in the rear wall 110 to facilitate fastening the impeller 100, for example, when the impeller is mounted on a spindle or shaft.

[0040] This article provides a method for manufacturing an impeller, the method comprising: Provide a mold, the mold includes The core, wherein the core contains a vacuum tube network, the vacuum tube network comprising multiple branching and interconnected vacuum tubes that are in fluid communication with the main vacuum tube, and Fiber elements arranged on the core; and By generating negative pressure in a vacuum pipeline network, the matrix material is supplied to a space at least defined by the core.

[0041] The vacuum network within the core, including branched and interconnected vacuum channels, enables improved transport of the matrix material. For example, the transport of the matrix material may be more reliable and faster, and / or the matrix material may be more uniformly distributed.

[0042] In some embodiments, the matrix material is supplied without applying pressure higher than atmospheric pressure.

[0043] In some embodiments, the method is vacuum-assisted resin transfer molding (VARTM). In some embodiments, the negative pressure is a vacuum or partial vacuum drawn in by one or more vacuum sources (e.g., vacuum pumps) via a main vacuum line through a network of vacuum lines within the core. In some embodiments, the main vacuum line is in fluid communication with a vacuum source. In some embodiments, more than one main vacuum line is in fluid communication with a single vacuum source. In some embodiments, the resulting negative pressure is in the range of -0.80 to -0.99 bar(g). This typically corresponds to a range of 0.01 to 0.2 bar(a).

[0044] In some embodiments, the mold reproduces a predetermined shape of the impeller being manufactured. In some embodiments, the diameter of the impeller being manufactured is in the range of 100 mm to 3500 mm, 150 mm to 3500 mm, 200 mm to 3500 mm, or 300 mm to 3000 mm, for example, from about 1500 mm to about 2000 mm. This method is well-suited for manufacturing large impellers with a diameter of about 1500 mm or larger. In some embodiments, the manufactured impeller has a fiber content of at least 50 wt%, and optionally up to 70 wt%, based on the total weight of the fiber and matrix material (in the impeller). The total weight of the fiber and matrix material is referred to herein as the sum of the fiber weight and the matrix material weight (in the impeller).

[0045] In some embodiments, the method is a method for manufacturing centrifugal impellers (centrifugal fans, centrifugal blowers). In particular, the method can be a method for manufacturing composite material centrifugal impellers. Centrifugal impellers are typically configured to pump, convey, and / or compress gases (e.g., air or hydrogen (H2)). The centrifugal impeller can be a centrifugal impeller used in turbomachinery.

[0046] In some embodiments, the mold is a non-sealed mold. In some embodiments, the method is performed without the use of a casting mold. The vacuum piping network inside the core allows the method to be performed without a sealed mold and / or a casting mold. However, a sealed mold and / or a casting mold may be used if desired, although not required.

[0047] In some embodiments, the mold includes a base plate and / or a top plate, with a core disposed between the base plate and the top plate and optionally fixed before the substrate material is supplied. The base plate may be configured to form the rear wall 110 of the impeller being manufactured, typically the outer surface of the rear wall 110 (excluding the surface from which the blades extend). Similarly, the top plate may be configured to form the front wall 120 of the impeller being manufactured, typically the outer surface of the front wall (excluding the surface from which the blades extend). In some embodiments, the base plate and / or the top plate are aluminum sheets.

[0048] In some embodiments, the space where the substrate material is supplied is defined by the core and other components of the mold. In some embodiments, the space where the substrate material is supplied is defined by the core, base plate, and / or top plate. In some embodiments, the space where the substrate material is supplied is defined by the core.

[0049] In this method, the mold includes a core and fibrous elements disposed on the core. The empty space into which the matrix material is supplied is typically defined such that the matrix material will contact the fibrous elements laid on the core. The fibrous elements may be impregnated with the matrix material. The space into which the matrix material is supplied is typically defined by the core or by the core and one or more other components of the mold (e.g., a top plate and / or a base plate), such that when the matrix material is supplied to said space, the fibrous elements disposed on the core are impregnated with the matrix, and the fibrous elements and the matrix material together are formed or shaped by the core (optionally together with other components of the mold) to give the impeller being manufactured its appropriate shape.

[0050] In some embodiments, the matrix material substantially fills the space to which the matrix material is supplied, at least defined by the core. In some embodiments, the method includes impregnating fibrous elements disposed on the core by supplying the matrix material into the space defined at least by the core. The space to which the matrix material is supplied may be a continuous space, or it may comprise more than one space that is not fluidly connected to each other. Preferably, the space to which the matrix material is supplied may be a continuous space.

[0051] In some embodiments, the core may optionally form the mold together with the fiber elements. The fiber elements may be laid in the mold, and thereafter are considered to be included in the mold. The vacuum tubing network inside the core allows this method to be implemented using a mold that is substantially composed of the core.

[0052] In some embodiments, the core includes one or more core elements or is substantially composed of one or more core elements. As used herein, unless otherwise stated, the term "core" covers an external core outside the blades of an impeller being manufactured, one or more internal cores (at least partially) enclosed within a respective blade of an impeller being manufactured, or both. In some embodiments, the mold includes an internal core for each blade being manufactured.

[0053] In some embodiments, the core includes at least an outer core. In some embodiments, the core includes an outer core and one or more inner cores.

[0054] In some embodiments, the core includes at least an outer core that forms the gaps between adjacent blades of the impeller in the impeller being manufactured. The outer core may include more than one core element. For example, the outer core may include a core element that forms a central region of the impeller being manufactured and other core elements that form the gaps between adjacent blades of the impeller.

[0055] The outer core that forms the gap between adjacent blades of, for example, an impeller being manufactured can be a single core element, or it can be assembled from one or more core elements, particularly from one or more layers stacked on top of each other.

[0056] In some embodiments, the core includes one or more (internal) core elements around which the blades of the impeller being manufactured are formed. The internal core elements are typically retained within the blades of the finished impeller. The internal core or core elements may be made of the same or different material as the external core or core elements.

[0057] In embodiments where the core includes an internal core element, a separate internal core element may be provided for each blade. In some embodiments, each blade includes or encapsulates an internal core element.

[0058] The mold may include an outer core and an inner core, wherein the outer core may optionally be formed by one or more outer core elements and the inner core may optionally be formed by one or more inner core elements.

[0059] The core includes a vacuum piping network comprising multiple branching and interconnected vacuum pipes. This vacuum piping network can be located within an outer core, an inner core, or both. In some embodiments, the vacuum piping network includes branching and interconnected vacuum pipes located at different heights within the core. In some embodiments, the vacuum piping network is a three-dimensional vacuum piping network. In some embodiments, a main vacuum pipe is in fluid communication with one or more branching and interconnected vacuum pipes.

[0060] In some embodiments, the vacuum piping network provides suction or negative pressure at one or more locations within the space where the matrix material is supplied. In some embodiments, the negative pressure guides the matrix material, particularly guiding it into and within the space where it is supplied.

[0061] In some embodiments, the vacuum tubing network has multiple openings on the surface of the core. These openings may be located on the surface where the fiber elements are arranged, and / or on the surface defining the space into which the matrix material is supplied. In this method, a negative pressure can be generated above these openings. Providing negative pressure to the space into which the matrix material is supplied through multiple vacuum tubing network openings is advantageous because it effectively divides the space into several injection zones, even in embodiments where the space is supplied by only one matrix material feed line opening.

[0062] In some embodiments, the branches of the interconnected vacuum lines have corresponding openings on the core surface defining the space into which the matrix material is supplied and / or on the core surface where the fiber elements are arranged.

[0063] In some embodiments, the core includes one or more feed lines at least partially disposed within the core. In some embodiments, the core includes a network of feed lines comprising a plurality of branching and interconnected feed lines disposed within the core. The feed lines may have one or more openings within the space where the base material is supplied. In embodiments where the space where the base material is supplied includes more than one space that is not in fluid communication with each other, each such space includes at least one feed line opening.

[0064] In some embodiments, the diameter of one or more feed lines, at least partially arranged within the core, is larger than the diameter of a plurality of branched and interconnected vacuum lines within the core. In some embodiments, the diameter of the plurality of branched and interconnected feed lines within the core is larger than the diameter of the plurality of branched and interconnected vacuum lines within the core. Preferably, the diameters being compared are the diameters of the supply side and the vacuum side closest to the space where the matrix material is supplied. The diameter of the vacuum line network is not necessarily constant, but may increase as it moves within the vacuum line network from the space where the matrix material is supplied toward the main vacuum line and / or the vacuum source.

[0065] Figure 2A non-limiting example embodiment of the outer core 200 is shown. The core 200 may have an approximately disk-shaped form and a considerable thickness. The core 200 may include a plurality of slots 210 for receiving blades of an impeller being manufactured. The slots 210 may be formed such that the outer edges of the core 200 remain continuous, thereby holding the portions of the core 200 together. Inside the core 200, a vacuum conduit network is provided, the vacuum conduit network including a plurality of branched and interconnected vacuum conduits 220 in fluid communication with a main vacuum conduit 230. The plurality of branched and interconnected vacuum conduits 220 may be positioned such that each slot 210 for receiving blades of an impeller being manufactured has at least two branch vacuum conduits 220 arranged therein. The branch vacuum conduits 220 may be connected to or in fluid communication with an annular vacuum conduit 240 arranged within the core 200. The annular vacuum line 240 may be in fluid communication with one or more main vacuum lines 230, which extend from inside the core 200 to the outside of the core 200 and are adapted to be connected to a vacuum source (not shown). A vacuum line network may, for example, be formed by interconnecting multiple branch vacuum lines 220 via the annular vacuum line 240, which is in fluid communication with one or more main vacuum lines 230 adapted to be connected to a vacuum source.

[0066] In some embodiments, the feed line network is simpler than the vacuum line network. However, as detailed above, in some embodiments, a feed line network including branch feed lines may be provided within the core 200, which is similar to the vacuum line network but typically has a larger diameter.

[0067] For example, such as Figure 2 As shown in the exemplary embodiment, a plurality of main feed lines 250 may be provided extending from the outside of the core 200 to the inside of the core 200. Within the core 200, the main feed lines 250 may be connected to an annular feed line 260, which is in fluid communication with a curved feed line 270, which is arranged such that each curved feed line has an opening leading to a slot 210 configured to receive blades of an impeller being manufactured.

[0068] Vacuum piping networks and optional feed piping networks are by no means limited to Figure 2 An exemplary embodiment. Although Figure 2Exemplary embodiments illustrate a number of, for example, branching and interconnected vacuum lines, main vacuum lines, main feed lines, slots configured to accommodate impeller blades, etc., but this disclosure is by no means limited to these, and other numbers of the aforementioned components or features may be present in other exemplary embodiments of the invention. Those skilled in the art will understand that, for example, the design and dimensions of the impeller to be manufactured can be taken into account when determining the number of such features. In some exemplary embodiments, the matrix material enters the space defined at least by the core from 5-10 different locations or openings.

[0069] In some embodiments, providing a mold includes forming or manufacturing a core.

[0070] In some embodiments, the core or core element is formed from one or more layers having their own thicknesses, and the plurality of branched and interconnected vacuum tube routes are formed from cavities in the layers.

[0071] In some embodiments, each core element includes a network of vacuum channels within it, the network comprising multiple branching and interconnected vacuum channels in fluid communication with a main vacuum channel. In some embodiments, each core element is formed of more than one layer having its own thickness, and the multiple branching and interconnected vacuum channels are formed in cavities within the layers.

[0072] Figure 3 An exemplary embodiment of the mold 300 is shown. Figure 3 In this design, mold 300 includes an outer core formed by multiple layers 310, each having its own thickness and stacked on top of each other. Multiple branching and interconnected vacuum lines (not shown) may be formed by cavities in at least some of the layers 310. Mold 300 may include a main vacuum line 230 for providing negative pressure and a main feed line 250 for supplying matrix material. The front wall 120 of the impeller being manufactured is arranged between the outer edge 320 and the central region 330 of the core.

[0073] In some embodiments, the core is at least partially formed of one or more layers, each having its own thickness. Some layers may include cavities on their surfaces, such as machined cavities, which form branching vacuum channels once another layer is stacked upon them. This other layer may include holes penetrating the other layer, positioned to create fluid connections or pathways between branching vacuum channels formed by cavities in different layers. In other words, branching can be formed by branching cavities in one or more layers upon which another layer is stacked, such as a layer providing fluid connections between layers having branching cavities. The branching vacuum channels may be in fluid communication with, for example, annular vacuum channels, and connections between branching vacuum channels in different layers can be provided by such (annular) vacuum channels.

[0074] In some exemplary embodiments, the core may include four or more (e.g., five or more) layers stacked on top of each other, and multiple branched and interconnected vacuum tubes are routed to form cavities in the layers.

[0075] In some embodiments, the core is at least partially formed using 3D printing. A computer model of the desired vacuum piping network and / or feed piping network within the core can be created, and then the core (or a portion thereof) is 3D printed based on that computer model.

[0076] In some embodiments, providing the mold includes: Provide cores, and Fiber elements are laid on the core.

[0077] In some embodiments, providing the mold includes providing a substrate, arranging a core on the substrate, laying fiber elements on the core, providing a top plate on top of the core with the fiber elements laid, and optionally securing the core between the substrate and the top plate. Optionally, some fiber elements may be provided on the substrate before arranging the core on the substrate.

[0078] In some embodiments, providing a mold includes placing (laying) a dried fibrous element on a core, for example as a preform of a predetermined arrangement.

[0079] This method can manufacture the impeller itself, or manufacture an impeller directly mounted on a shaft or mandrel. In some embodiments, the impeller is manufactured without, for example, mounting on a shaft or mandrel, before the supply of matrix material, optional curing, and / or optional removal of the core are performed. A finished or near-finished impeller can then be installed. The supply of matrix material can be stopped (or optionally paused) when the space to which it has been supplied is substantially filled. The vacuum conduit network within the core, particularly its branch vacuum conduits, can be sized to allow matrix material to seep out while preventing a large amount of matrix material from entering the vacuum conduit network. In some embodiments, the vacuum conduits of the vacuum conduit network, particularly the branches of the interconnecting vacuum conduits, are sized to allow gas (e.g., air) to pass through while preventing (large) flow of matrix material within the vacuum conduit network. In some embodiments, when this method is performed, the feed lines or feed network primarily comprise matrix material, while the vacuum conduit network primarily comprises gas, such as air.

[0080] In some embodiments, the method includes curing the matrix material, preferably by heating, after the matrix material has been supplied to the mold. In some embodiments, curing is carried out in an oven or autoclave.

[0081] In some embodiments, the mold is placed in a vacuum bag before the matrix material is fed into the mold. The mold may remain in the vacuum bag during the matrix material feeding and optionally during curing. In some embodiments, the mold is placed in the vacuum bag before curing. The vacuum bag may be removed after the matrix material feeding is complete and / or after optional curing is complete.

[0082] In some embodiments, the method includes removing the mold after the supply of the base material and optional curing. In some embodiments, the method includes, preferably, removing the core by machining after the supply of the base material and optional curing. The core may be a disposable core, i.e., it is used or can be used to manufacture an impeller.

[0083] In some embodiments, the core is a removable, breakable, and / or destructible core. Particularly in the case of an external core, the core can be removed after the base material is supplied and optionally cured. Removing the core may include breaking it into smaller fragments.

[0084] In some embodiments, the method includes removing the outer core (while retaining the inner core within the blade, where applicable). The impeller under manufacture is typically produced by machining the core and / or mold. Alternatively, finishing steps and / or treatments may be applied to produce a finished impeller. In this document, removing the core and / or removing the mold is understood to encompass embodiments where a small or very small amount of core material may remain on the impeller surface.

[0085] In some embodiments, the method includes removing the mold from the vacuum bag and removing the mold to obtain the impeller.

[0086] In some embodiments, the core is a machinable core. Compared to, for example, a fusible core (such as a wax core), a machinable core allows for more precise and / or more reliable formation of a vacuum piping network and, optionally, a feed piping network within the core. Examples of machinable core materials include, but are not limited to, polymers, wood, and / or ceramics.

[0087] In some embodiments, the machinable core is formed from a polymer. Examples of such polymers include, but are not limited to, epoxy resins, phenolic resins, polypropylene, polyurethane, polyvinyl chloride (PVC), acrylonitrile-butadiene-styrene copolymer (ABS), cellulose acetate, polyethylene (PE), polypropylene (PP), and / or polyamide (PA).

[0088] In some embodiments, the core is a machinable core formed from polymer foam. The density of the polymer foam can be at least 30 kg / m³. 3 Or at least 60 kg / m 3 Or at least 80 kg / m 3And preferably up to 1000 kg / m 3 In some embodiments, the core is made of material with a density of 30 kg / m³. 3 Up to 160 kg / m 3 Machinable cores formed from polymer foams within the specified range. Such polymer foams may be composed of one or more of epoxy resin, phenolic resin, polypropylene, polyurethane, polyvinyl chloride (PVC), acrylonitrile-butadiene-styrene copolymer (ABS), and / or cellulose acetate.

[0089] In particular, in embodiments where the vacuum piping network (and optional feed piping network) within the core is formed by machining, the core material may be a polymer foam as described above.

[0090] In particular, in embodiments where the core element is formed by 3D printing, the core material may be selected from one or more of polyethylene (PE), polypropylene (PP), and / or polyamide (PA).

[0091] In some embodiments, the fiber elements are fabric elements, meaning they comprise a large number of interwoven fibers (of a certain length), such as fibers woven, knitted, sewn, and / or twisted together. In some embodiments, the fiber elements are formed from unidirectional fibers, for example, forming unidirectional tapes or the like. In some embodiments, the fibers of the fiber elements have a linear shape. Fiber elements may consist essentially of fibers and typically have a predetermined size and type.

[0092] In some embodiments, the fiber element is formed of carbon fibers. In some embodiments, the fiber element is a preform. As used herein, a preform refers to a fiber element formed of a large number of interwoven (e.g., braided) fibers and having a specific (typically predetermined) size. Preforms can be obtained, for example, by cutting.

[0093] Fiber elements can also be provided as prepregs. In this document, prepreg refers to fiber elements impregnated with a matrix material prior to layup, i.e., before the fiber elements are arranged in the mold and / or onto the core, particularly fiber elements as described above. The matrix material of the prepreg can be, for example, as described below.

[0094] Therefore, this paper provides a method for manufacturing an impeller, the method comprising: Provide a mold, the mold includes A core, wherein the core includes within it a network of vacuum lines comprising multiple branching and interconnected vacuum lines in fluid communication with a main vacuum line; and Prepreg fiber elements arranged on the core; and A negative pressure is generated in the vacuum tubing network to press (at least some) of the prepreg fiber elements onto the core.

[0095] When the fiber element is a prepreg, there is no need to supply matrix material separately because the prepreg already includes it. The core of this disclosure includes a network of vacuum channels within it, and a negative pressure is generated in the vacuum channel network, which can be used in the prepreg process to compress the prepreg towards the core and / or conform the prepreg to the shape of the core. In some embodiments where the fiber element is a prepreg, the method is performed without supplying matrix material separately to at least the space defined by the core. In addition to the supply of matrix material, the method for making the fiber element a prepreg can be the method described herein.

[0096] As those skilled in the art will understand, the matrix material is in a fluid or liquid state when supplied to the mold. In some embodiments, the matrix material is a resin.

[0097] The matrix material may be selected from one or more thermosetting polymer resins and / or one or more thermoplastic polymer resins. The thermosetting polymer resin is preferably selected from one or more of the following: epoxy resin, phenolic polymer, polyester, vinyl ester, amine, furan resin, polyimide (PI), bismaleimide (BMI), cyanate ester (CE), phthalonitrile, and / or benzoxazine; the thermoplastic polymer resin is preferably selected from one or more of the following: polyphenylene sulfide (PPS), polyamide (PA), polymethyl methacrylate (PMMA), liquid crystal polymer... Poly(LCP), polyoxymethylene (POM), polyamide-imide (PAI), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyaryletheretherketone (PAEK), polyethylene terephthalate (PET), polycarbonate (PC), polyethylene (PE), polyetherimide (PEI), polyethersulfone (PES), polyphthalamide (PPA), polyvinyl chloride (PVC), polyurethane (PU), polypropylene (PP), polystyrene (PS), polyphenylene ether (PPO), and / or polyimide (PI).

[0098] In some embodiments, the matrix material comprises one or more thermosetting polymer resins or is substantially composed of one or more thermosetting polymer resins, preferably selected from one or more of the following: epoxy resins, phenolic polymers, polyesters, vinyl esters, amines, furan resins, polyimide (PI), bismaleimide (BMI), cyanate esters (CE), phthalonitrile and / or benzoxazine.

[0099] In some embodiments, the matrix material comprises one or more one-component or two-component epoxy resins, vinyl esters and / or polyester resins, or is substantially composed of one or more one-component or two-component epoxy resins, vinyl esters and / or polyester resins.

[0100] In some embodiments, the matrix material may include a small amount of solid particles, which may be used, for example, as an additive to reinforce or protect certain components of the impeller being manufactured.

[0101] In some embodiments, the method includes providing a 3D-printed metal part or element having a shape conforming to a portion of the impeller surface, and placing the formed metal part in a mold between a core and a fibrous element disposed on the core. The placement of the metal element can be performed before the substrate material is supplied. This metal element associated with a portion of the impeller surface can protect that portion of the impeller surface from erosion and / or corrosion typically caused by the working fluid. In some embodiments, the metal element is made of titanium and / or aluminum, preferably titanium.

[0102] In some embodiments, the 3D-printed metal element has a shape that mates with or conforms to a portion of the impeller surface, such that the shape of the 3D-printed metal sheet provides shape locking between the metal element and the impeller surface. This shape locking improves the fixation of the metal element to the impeller. 3D printing can provide a predetermined shape for the metal element with extremely high precision.

[0103] In some embodiments, the formed 3D-printed metal part or element includes spikes or protrusions on its inner surface, i.e., on the surface facing the impeller. The spikes improve the fixation of the formed metal element to the impeller by penetrating the fibrous element and / or the matrix material.

[0104] In some embodiments, the shaped metal element is positioned on the blade (edge) of the impeller.

[0105] Figure 4 A flowchart of a method according to an example embodiment is shown. In step 410, a mold including a core is provided. The core is preferably a core as described above. In a second step 420, fiber elements are arranged on the core, and in a third step 430, a matrix material is supplied to a space defined at least by the core. The supply of the matrix material can be achieved by creating a (partial) vacuum or negative pressure in a network of vacuum channels within the core, as described above. Preferably, no external (above atmospheric pressure) pressure is applied to the supply side.

[0106] In some embodiments, a overflow step is performed after the supply of the matrix material. In the overflow step, excess matrix material is removed from the space in which it was supplied. In some embodiments, the method includes curing the matrix material after the supply of the matrix material and optionally after overflow, preferably by heating, for example, heating to about 100°C or higher.

[0107] In some embodiments, after curing, the core is removed by machining to obtain the impeller. In some embodiments, the method includes machining the impeller as a finishing step to obtain its predetermined dimensions.

[0108] This document also provides a core comprising a vacuum tubing network including multiple branching and interconnected vacuum tubing. The core may be a core in conjunction with the method described herein. This document also provides the use of the core in the manufacture of composite materials, particularly in the manufacture of fiber-reinforced composite materials. In some embodiments, the use includes generating or providing negative pressure within the vacuum tubing network of the core.

[0109] This article also provides a mold for manufacturing an impeller, the mold comprising a core as defined above.

[0110] This article provides a method for manufacturing composite materials, including providing a mold comprising a core having a vacuum network therein as described above, fiber elements disposed on the core, and a matrix material located within the mold; and Negative pressure is provided in the vacuum tubing network to compress or move the fiber elements and / or matrix material toward the core.

[0111] Without limiting the scope and / or interpretation of the claims, certain technical effects and / or advantages of one or more exemplary embodiments disclosed herein are set forth below. One advantage is that impellers, even those with complex blade structures, can be integrally molded, for example, in a single supply and curing cycle of the matrix material, without the need for subsequent attachment or joining of impeller components. Integral impellers are mechanically stronger and / or have improved structural integrity compared to impellers with subsequently attached or joined components. Furthermore, the number of process steps in impeller manufacturing can be reduced. A technical effect is a high fiber content (the percentage of fiber weight based on the total weight of fibers and matrix material in the impeller). The vacuum piping network and the negative pressure generated therethrough can improve the matrix material distribution and / or achieve a denser structure. The vacuum piping network and the negative pressure generated therethrough contribute to high-quality, reliable production. This method offers a higher manufacturing success rate compared to prior art methods. The improved matrix distribution contributes to the high fiber content. Another advantage is that casting molds or sealing molds are not necessarily required. This allows for flexible impeller production, even for single-piece impellers. Another advantage is the ability to manufacture large single objects using vacuum-assisted resin transfer molding (VARTM) or similar methods.

[0112] Various embodiments have been presented. It should be understood that the words “comprising,” “including,” and “containing” are used in this document as open-ended expressions and are not intended to indicate exclusivity.

[0113] The foregoing description, through non-limiting examples of specific implementations and embodiments, provides a complete and informative description of the best mode of carrying out the invention as currently contemplated by the inventors. However, it will be apparent to those skilled in the art that the invention is not limited to the details of the embodiments presented above, but can be implemented in other embodiments using equivalent means or different combinations of embodiments without departing from the characteristics of the invention.

[0114] Furthermore, certain features of the disclosed exemplary embodiments may be used advantageously without corresponding use of other features. Therefore, the above description should be considered merely as an illustration of the principles of the invention and not as a limitation thereof. Consequently, the scope of the invention is limited only by the appended claims.

Claims

1. A method for manufacturing an impeller, the method comprising: A mold is provided, the mold comprising: A core, wherein the core internally includes a vacuum tubing network, the vacuum tubing network comprising multiple branching and interconnected vacuum tubing in fluid communication with a main vacuum tubing; and Fiber elements arranged on the core; and By generating negative pressure in the vacuum pipeline network, the matrix material is supplied to the space defined at least by the core.

2. The method according to claim 1, wherein, The multiple branched and interconnected vacuum lines include branched vacuum lines at different heights within the core.

3. The method according to claim 1 or 2, wherein, At least a portion of the core is formed of more than one layer having a corresponding thickness, and the plurality of branched and interconnected vacuum tube routes are formed by cavities in the layers.

4. The method according to any one of the preceding claims, wherein, The vacuum tubing network has multiple openings on the surface of the core.

5. The method according to any one of the preceding claims, wherein, The matrix material is supplied to a space defined at least by the core via a feed line network, the feed line network comprising a plurality of branched and interconnected feed lines arranged within the core.

6. The method according to claim 5, wherein, The diameter of the multiple branched and interconnected feed lines within the core is larger than the diameter of the multiple branched and interconnected vacuum lines within the core.

7. The method according to any one of the preceding claims, wherein, The method includes removing the core after the substrate material is supplied and optionally cured, preferably by machining.

8. The method according to any one of the preceding claims, wherein, The core is a machinable core, preferably a machinable core formed from one or more polymers, more preferably a core with a density of at least 30 kg / m³. 3 The polymer foam is formed into a machinable core, wherein the polymer foam is preferably selected from one or more of epoxy resin, phenolic resin, polypropylene, polyurethane, polyvinyl chloride (PVC), acrylonitrile-butadiene-styrene copolymer (ABS) and / or cellulose acetate.

9. The method according to any one of the preceding claims, wherein, The fiber element is carbon fiber.

10. A method for manufacturing an impeller, the method comprising: A mold is provided, the mold comprising: A core, wherein the core internally includes a vacuum tubing network, the vacuum tubing network comprising multiple branching and interconnected vacuum tubing in fluid communication with a main vacuum tubing; and Prepreg fiber elements arranged on the core; and A negative pressure is generated in the vacuum tubing network to press the prepreg fiber elements onto the core.

11. A core, the core including a vacuum tube network, the vacuum tube network including a plurality of branched and interconnected vacuum tubes.

12. The core according to claim 11, wherein, The multiple branched and interconnected vacuum lines include branched vacuum lines at different heights within the core.

13. The core according to claim 11 or 12, wherein, The core is formed at least in part by more than one layer having a corresponding thickness, and a plurality of interconnected branch vacuum tubes are formed by cavities in the layers.

14. The core according to any one of claims 11-13, wherein, The vacuum tubing network has multiple openings on the surface of the core.

15. The core according to any one of claims 11-14, wherein, The core includes multiple interconnected branched feed lines arranged within the core.

16. The core according to claim 15, wherein, The diameter of the multiple branched and interconnected feed lines within the core is larger than the diameter of the multiple branched and interconnected vacuum lines within the core.

17. A mold for manufacturing an impeller, the mold comprising a core according to any one of claims 11-16.

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