Bionic wear-resistant hub structure and centrifugal pump impeller

Abstract

This invention discloses a biomimetic wear-resistant hub structure and a centrifugal pump impeller, relating to the field of fluid machinery anti-silt erosion technology. The biomimetic wear-resistant hub structure is based on a fractal Z-shaped structure designed biomimeticly to mimic the multi-layered structure of scales on the surface of a desert lizard, and is arranged on the hub body in the easily worn areas adjacent to the suction inlet of each blade. Each fractal Z-shaped structure utilizes rigid support components such as a primary contact crown surface and a primary contact saddle to provide primary support, and utilizes a primary energy dissipation truss composed of multiple secondary Z-shaped structural units to achieve stepwise energy dissipation. Through this rigid-flexible coupled multi-scale fractal structure, multi-scale vortices can be induced in the flow field, altering the trajectory of sediment particles, reducing impact kinetic energy, and optimizing the impact mode, thus synergistically improving the hub's wear resistance from a solid-liquid two-phase mechanical perspective. This invention has a clear structure, strong manufacturability, and can significantly reduce the wear rate of the hub under sandy water flow conditions, extending the service life of the equipment.

Description

Technical Field

[0001] This invention relates to the field of anti-erosion technology for fluid machinery, and particularly to a biomimetic anti-wear hub structure and centrifugal pump impeller suitable for centrifugal pump impellers in fluid media containing silt. Background Technology

[0002] As the core working component of rotating machinery, the impeller rotates at high speed during operation. The hub, as the structural core of the impeller, bears complex loads. Under conditions of sediment-laden water flow, the hub surface faces severe silt abrasion, especially in the area near the inlet of the blade suction surface, where wear is particularly pronounced, often leading to material perforation failure. When operating conditions (especially high-flow-rate conditions) deviate from the design point or the inlet pressure is insufficient, cavitation is also prone to occur in this area, resulting in combined wear and cavitation damage, significantly reducing the service life and operational reliability of the impeller and equipment.

[0003] Current research on wear-resistant technologies largely focuses on blade profile optimization or surface coatings, with relatively little research on wear-resistant structural design for the hub itself. With the development of bionics, the excellent wear-resistant properties of biological surfaces have attracted widespread attention. However, the flow structure at the hub-blade interface is complex, with large velocity gradients and well-developed vortices. Sediment particles easily accumulate and repeatedly impact in localized areas. Directly applying ordinary bionic textures or single-scale surface structures to this region is insufficient to meet the long-term wear resistance requirements under sediment-laden water flow conditions.

[0004] Therefore, it is necessary to propose a biomimetic wear-resistant structure suitable for the locally wear-prone areas of the hub to improve the operational reliability of centrifugal pump impellers in sandy water flow. Summary of the Invention

[0005] The purpose of this invention is to provide a biomimetic wear-resistant hub structure and centrifugal pump impeller capable of operating in silt-containing fluid media. Based on the multi-layered wear-resistant characteristics of the scales on the surface of a desert lizard, it employs a biomimetic design of a rigid-flexible coupled fractal Z-shaped structure, which is positioned on the hub body in a wear-prone area adjacent to the suction inlet of the blades. This structure withstands the main particle impacts through rigid support components such as the primary contact crown and primary contact saddle, and dissipates the impact energy stepwise through a primary energy dissipation truss composed of multiple secondary Z-shaped structural units. Simultaneously, it induces local multi-scale vortices to alter the trajectory and impact mode of silt particles, thereby reducing localized hub wear and addressing the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a biomimetic wear-resistant wheel hub structure, including a wheel hub body and a fractal Z-shaped structure disposed on the surface of the wheel hub body. The wheel hub body has a wear-prone protection area adjacent to the inlet of the blade suction surface, and the fractal Z-shaped structure is disposed in the wear-prone protection area. The fractal Z-shaped structure includes a primary contact crown surface, a primary contact base saddle, and a primary energy dissipation truss. The primary contact crown surface and the primary contact base saddle are spaced apart. The primary energy dissipation truss is connected between the end of the primary contact crown surface and the beginning of the primary contact base saddle. The primary contact crown surface, the primary contact base saddle, and the primary energy dissipation truss together constitute a primary Z-shaped structural unit. The primary energy dissipation truss is composed of n secondary Z-shaped structural units connected in series in a tail-to-tail manner, where n is an integer greater than 1. Both the primary contact crown surface and the primary contact base saddle are rigid support parts, while the primary energy dissipation truss is a flexible energy dissipation part, so that the fractal Z-shaped structure forms a multi-scale wear-resistant structure with rigid-flexible coupling.

[0007] Preferably, the n secondary Z-shaped structural units constituting the primary energy dissipation truss have the same or similar Z-shaped topology and are arranged continuously along the extension direction of the primary energy dissipation truss. Each of the two-dimensional Z-shaped structural units includes a two-dimensional contact crown surface, a two-dimensional contact base saddle, and a two-dimensional energy dissipation truss. The secondary contact base saddle and the secondary contact crown surface are spaced apart, and the secondary energy dissipation truss is connected between the end of the secondary contact crown surface and the beginning of the secondary contact base saddle; Between any two adjacent secondary Z-shaped structural units, the end of the secondary contact saddle of the secondary Z-shaped structural unit closest to the starting end is connected to the starting end of the secondary contact crown surface of the next adjacent secondary Z-shaped structural unit.

[0008] Preferably, in any one of the first-level Z-shaped structural units: The first secondary Z-shaped structural unit located at the starting end of the primary energy dissipation truss has its secondary contact crown surface connected to the end of the primary contact crown surface, and the extension direction of the secondary contact crown surface and the primary contact crown surface form an angle β; the value of β ranges from 20° to 60°. The nth secondary Z-shaped structural unit located at the end of the primary energy dissipation truss has its secondary contact base saddle end connected to the starting end of the primary contact base saddle.

[0009] Preferably, in any of the first-stage Z-shaped structural units: the first-stage contact crown surface and the first-stage contact base saddle are parallel to each other, and the extension planes of the first-stage contact crown surface and the first-stage contact base saddle both form an acute angle α with the surface of the wheel hub body; the value of α ranges from 10° to 30°. In any of the secondary Z-shaped structural units: the secondary contact crown surface and the secondary contact base saddle are parallel to each other.

[0010] Preferably, the design length of the first-stage energy dissipation truss along its length direction is... L In each of the secondary Z-shaped structural units, the length of the secondary energy dissipation truss is... L / n The lengths of the secondary contact crown surface and the secondary contact base saddle are both L / (2n) .

[0011] Preferably, in any one of the first-level Z-shaped structural units: The first secondary Z-shaped structural unit located at the starting end of the primary energy dissipation truss has its starting end of the secondary energy dissipation truss coinciding with the starting end of the primary energy dissipation truss. The nth secondary Z-shaped structural unit located at the end of the primary energy dissipation truss has its secondary energy dissipation truss end coinciding with the end of the primary energy dissipation truss.

[0012] Preferably, the secondary Z-shaped structural unit has topological similarity to the primary Z-shaped structural unit, and the overall size of the secondary Z-shaped structural unit is 1 / 5 to 1 / 20 of that of the primary Z-shaped structural unit.

[0013] Preferably, in any of the two-stage Z-shaped structural units, the design length of the two-stage energy dissipation truss along its length direction is... l The representative particle size of the sediment particles in the sand-laden water flow under the designed operating conditions of the hub body is: d , d Median particle size d 50 or the particle size corresponding to the peak value of the particle size distribution; l and d The ratio range is 5≤ l / d ≤50.

[0014] Preferably, both the primary contact crown surface and the primary contact base saddle are made of materials with high elastic modulus and high wear resistance; each of the secondary Z-shaped structural units is made of materials with high fatigue strength and high toughness.

[0015] The present invention also proposes a centrifugal pump impeller, comprising the biomimetic wear-resistant hub structure described in any one of the above claims and a plurality of blades, wherein the plurality of blades are arranged at circumferential intervals along the hub body and connected to the hub body; the area of ​​the suction surface inlet of each blade adjacent to the hub body is the wear-prone protection zone, and each wear-prone protection zone is provided with the fractal Z-shaped structure.

[0016] The present invention achieves the following technical effects compared to the prior art: The biomimetic wear-resistant hub structure proposed in this invention features a rational structural design. Based on the multi-layered structure of scales on the surface of a desert lizard, a fractal Z-shaped structure is biomimeticly designed and arranged on the hub body in the easily worn areas adjacent to the suction inlet of each blade. Multiple fractal Z-shaped structures are arranged circumferentially along the hub body. Each fractal Z-shaped structure utilizes rigid support components such as a primary contact crown and a primary contact saddle to provide primary support. Energy is dissipated step-by-step using a primary energy dissipation truss composed of multiple secondary Z-shaped structural units. Through this rigid-flexible coupled multi-scale fractal structure, multi-scale vortices can be induced in the flow field, altering the trajectory of sediment particles, reducing impact kinetic energy, and optimizing the impact mode. This synergistic improvement in the hub's wear resistance from both solid-liquid two-phase mechanical perspectives makes it suitable for high-speed rotating mechanical impellers in sediment-containing fluid media.

[0017] The fractal Z-shaped structure of the present invention uses multiple secondary Z-shaped structural units as micro-refinements of the primary energy dissipation truss, and arranges them through specific angles α and β. This multi-level fractal complex structure can more efficiently match the impact energy spectrum of sediment particles, and achieve a synergistic anti-wear effect.

[0018] The present invention has a clear structure and strong manufacturability, and can significantly reduce the wear rate of wheel hubs under sandy water conditions, thus extending the service life of the equipment.

[0019] The biomimetic wear-resistant hub structure described above can be applied to centrifugal pump impellers to provide wear protection. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall assembly structure of the biomimetic wear-resistant hub structure and blades disclosed in an embodiment of the present invention; Figure 2 for Figure 1 The main view; Figure 3 This is a schematic diagram of the radial cross-section of the wheel hub body disclosed in an embodiment of the present invention; Figure 4 This is a perspective view of the radial cross-sectional structure of the impeller disclosed in an embodiment of the present invention; Figure 5 This is a schematic diagram of the axial cross-section of the impeller disclosed in an embodiment of the present invention; Figure 6 for Figure 5 A three-dimensional view of the mid-section structure; Figure 7 This is a schematic diagram of the fractal Z-shaped structure disclosed in an embodiment of the present invention; Figure 8 for Figure 7 Schematic diagram of the secondary Z-shaped structural unit; Figure 9 This is a schematic diagram showing the markings of some parameters in the fractal Z-shaped structure disclosed in an embodiment of the present invention; Figure 10 This is a schematic diagram showing the markings of some parameters in the fractal Z-shaped structure disclosed in an embodiment of the present invention; Figure 11 This is a diagram showing the distribution of mud and sand wear on the conventional hub of a water pump impeller. Figure 12 The diagram shows the wear distribution of mud and sand on the impeller of a water pump using the biomimetic wear-resistant hub structure of this invention.

[0022] Figure 13 This is a schematic diagram comparing the mechanism of the influence of a conventional wheel hub and the biomimetic wear-resistant wheel hub structure of this invention on the impact path of mud and sand particles.

[0023] In the figure, the attached reference numerals are: 1-Centrifugal pump impeller; 2-Wheel hub body; 3- Fractal Z-shaped structure; 31- Primary Z-shaped structural unit; 311- Primary energy dissipation girder; 312- Primary contact crown surface; 313- Primary contact saddle; 32- Secondary Z-shaped structural unit; 321- Secondary energy dissipation girder; 322- Secondary contact crown surface; 323- Secondary contact saddle; 4-Leaf. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] One objective of this invention is to provide a biomimetic wear-resistant wheel hub structure that can operate in a silt-containing fluid medium. Based on the multi-layered structure of scales on the surface of a desert lizard, a fractal Z-shaped structure is designed. Rigid support components such as the primary contact crown and primary contact saddle provide the main support. The primary energy dissipation truss, composed of multiple secondary Z-shaped structural units, achieves energy dissipation at each stage. This induces unique multi-scale vortices in the flow field, effectively changing the impact mode of silt particles and significantly reducing the wear rate from a mechanical perspective, thus solving the problem of easy wear in existing wheel hub structures.

[0026] Another objective of this invention is to provide a centrifugal pump impeller incorporating the above-mentioned biomimetic wear-resistant hub structure, in order to solve the problem of easy wear of existing hub structures.

[0027] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] This embodiment proposes a centrifugal pump impeller 1, which includes a biomimetic wear-resistant hub structure and multiple blades 4. The biomimetic wear-resistant hub structure includes a hub body 2 and a fractal Z-shaped structure 3 disposed on the surface of the hub body 2. The multiple blades 4 are arranged at intervals along the circumference of the hub body 2 and are connected to the hub body 2; the fractal Z-shaped structure 3 is disposed in the region of the suction surface inlet of each blade 4 adjacent to the hub body 2, see [reference]. Figure 1 and Figure 2 Each of the six blades 4 has a fractal Z-shaped structure 3 corresponding to its suction surface inlet. The fractal Z-shaped structure 3 employs a special configuration design, comprising a primary Z-shaped structural unit 31 and a secondary Z-shaped structural unit 32. The energy dissipation truss of the primary Z-shaped structural unit 31 is continuously arrayed from head to tail by several secondary Z-shaped structural units 32, forming a fractal structure. The contact crown and contact saddle of the primary Z-shaped structural unit 31 are distributed on both sides of its energy dissipation truss. Each secondary Z-shaped structural unit 32 includes its own contact crown, energy dissipation truss, and contact saddle. For distinction, the energy dissipation truss, contact crown, and contact saddle of the primary Z-shaped structural unit 31 are defined as primary energy dissipation truss 311, primary contact crown 312, and primary contact saddle 313, respectively, while the energy dissipation truss, contact crown, and contact saddle of the secondary Z-shaped structural unit 32 are defined as secondary energy dissipation truss 321, secondary contact crown 322, and secondary contact saddle 323, respectively. Both the primary contact crown surface 312 and the primary contact base saddle 313 adopt rigid structures as rigid support parts, while the primary energy dissipation truss 311, which is composed of an array of secondary Z-shaped structural units 32, is a flexible energy dissipation part.

[0029] The fractal Z-shaped structure 3 is positioned between the leading edge of blade 4 and 30% of the chord length, without extending to the outer periphery of the hub. This placement is based on locations with severe wear and cavitation damage. The fractal Z-shaped structure 3 extends along the curvature or flow direction of blade 4, with its width extending along the spanwise direction of the inter-blade flow channel. This makes the Z-shaped geometry approximately perpendicular to the incoming flow direction, thus inducing multi-scale vortices. Furthermore, this approximately perpendicular orientation also helps disperse the impact energy of particles carried by the water flow. Each fractal Z-shaped structure 3 extends along the flow direction, with its width extending along the spanwise direction of the inter-blade flow channel. The two tips of each secondary Z-shaped unit, one facing downstream and the other upstream, create an effect similar to a compressed spring, dissipating the impact energy of sediment.

[0030] In this invention, "first-level contact crown surface 312" refers to the surface of the fractal Z-shaped structure 3 located on the side where the particles mainly flow or on the side that first bears the impact of the particles. It is mainly used to bear the direct impact of the mud and sand particles and provide rigid support. "First-level contact base saddle 313" refers to the support surface of the fractal Z-shaped structure 3 located downstream of the first-level contact crown surface 312 or close to the hub body 2. It is mainly used to transfer the load to the hub body 2 and maintain structural stability. "First-level energy dissipation truss 311" refers to the intermediate connecting structure connecting the first-level contact crown surface 312 and the first-level contact base saddle 313. It achieves energy dissipation through bending, torsion or local deformation by arranging multiple secondary Z-shaped structural units 32 in series.

[0031] "Secondary contact crown 322," "secondary contact base saddle 323," and "secondary energy dissipation truss 321" are respectively the local structures in the secondary Z-shaped structural unit 32 corresponding to the functions of the primary contact crown 312, primary contact base saddle 313, and primary energy dissipation truss 311. The fractal Z-shaped structure 3 does not require strict self-similarity in a mathematical sense, but rather refers to the similarity between the primary Z-shaped structural unit 31 and the secondary Z-shaped structural unit 32 in terms of Z-shaped topological configuration and load transfer path. "Topological configuration" refers to the connection relationships and spatial structural characteristics of an object that remain unchanged under continuous deformation (such as tension and bending, but excluding tearing or adhesion). This is a well-known definition among those skilled in the art and will not be elaborated upon here.

[0032] This invention is inspired by the multi-layered structure of the scales on the surface of a desert lizard. This structure effectively resists impacts from particles of varying sizes and directions across a wide velocity range in a windy and sandy environment, exhibiting excellent wear resistance. Through biomimetic analysis of the multi-directional cross-sectional morphology of the lizard scales, it was found that they are composed of basic Z-shaped structural units continuously distributed along the body surface, exhibiting multi-scale characteristics. Based on this, this invention proposes the aforementioned multi-level, multi-scale, rigid-flexible coupled Z-shaped biomimetic structure (i.e., fractal Z-shaped structure 3) arranged at the junction of the hub body 2 and the suction surface inlet of the blade 4.

[0033] In the biomimetic wear-resistant hub structure, the energy dissipation girder of the primary Z-shaped structural unit 31 is composed of multiple secondary Z-shaped structural units 32 connected end-to-end, making the overall energy dissipation girder of the primary Z-shaped structural unit 31 composed of multi-level Z-shaped units. The scale distribution of the multi-level Z-shaped units is determined based on the impact energy spectrum of the sediment particles to be resisted. The rigid part of the primary Z-shaped structural unit 31 is used to resist the impact of large-diameter, high-kinetic-energy particles, while the flexible part of the secondary Z-shaped unit 32 is used to dissipate the impact energy of small-diameter, low-kinetic-energy particles and induce the generation of a vortex flow field.

[0034] In some feasible implementations, refer to Figures 7-10 The primary contact crown surface 312 of the primary Z-shaped structural unit 31 is parallel to the primary contact base saddle 313, and the extended planes of the two form an acute angle α with the surface of the hub body 2. The value of α can be 10°~30°, specifically 10°, 15°, 20°, 25° or 30°.

[0035] In some feasible implementations, in each primary Z-shaped structural unit 31: The first secondary Z-shaped structural unit 32, located at the starting end of the primary energy dissipation truss 311, has its secondary contact crown 322 connected to the end of the primary contact crown 312; and the extension directions of the secondary contact crown 322 and the primary contact crown 312 form an angle β. The value of β can range from 20° to 60°, specifically 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, or 60°. The last secondary Z-shaped structural unit 32, located at the end of the primary energy dissipation truss 311, has its secondary contact saddle 323 connected at its end to the starting end of the primary contact saddle 313; and the extension directions of the secondary contact saddle 323 and the primary contact saddle 313 form an angle β. The value of β can range from 20° to 60°, specifically 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, or 60°.

[0036] The aforementioned range of the included angle β can balance the turning characteristics and smooth connection of the secondary Z-shaped structural unit 32; if β is too small, the turning is not obvious and the energy dissipation effect is weakened; if β is too large, the turning is too abrupt and local stress concentration is easily generated. Therefore, this range of included angle β is conducive to ensuring structural continuity and impact energy dissipation effect.

[0037] By setting α and β in synergy, the angle of attack of the fractal Z-shaped structure 3 relative to the hub surface and the direction of incoming flow can be adjusted, thereby changing the local impact angle and impact path of the sediment particles.

[0038] In some feasible implementations, in the primary energy dissipation truss 311 of the primary Z-shaped structural unit 31: between any two adjacent secondary Z-shaped structural units 32, the end of the secondary contact base saddle 323 of the secondary Z-shaped structural unit 32 near the starting end is connected to the starting end of the secondary contact crown surface 322 of the next adjacent secondary Z-shaped structural unit 32, and several secondary Z-shaped structural units 32 are connected in series to form the complete energy dissipation truss of the primary Z-shaped structural unit 31.

[0039] In some feasible implementations, the energy dissipation truss of the first-level Z-shaped structural unit 31 is composed of n identical or similar second-level Z-shaped structural units 32 connected end-to-end in sequence, where n is an integer greater than 1. Wherein, if the design length of the first-level energy dissipation truss 311 along its length direction is... L Then the length of the secondary energy dissipation truss 321 of each secondary Z-shaped structural unit 32 is L / n That is, the design length of the primary energy dissipation truss 311 is equal to the sum of the lengths of the secondary energy dissipation trusses 321 of each secondary Z-shaped structural unit 32. Furthermore, it is preferred that in each secondary Z-shaped structural unit 32, the lengths of the secondary contact crown surface 322 and the secondary contact base saddle 323 are both... L / (2n) .like Figures 7-9 As shown, this is n Schematic diagram of the structure when =4.

[0040] In some feasible implementations, it is preferable that the secondary contact crown surface 322 and the secondary contact base saddle 323 in each secondary Z-shaped structural unit 32 are parallel to each other.

[0041] In some feasible implementations, the secondary Z-shaped structural unit 32 has the same or similar Z-shaped topology as the primary Z-shaped structural unit 31. When the two have similar Z-shaped topology, the overall size of the secondary Z-shaped structural unit 32 is 1 / 5 to 1 / 20 of that of the primary Z-shaped structural unit 31.

[0042] In some feasible implementations, the characteristic dimensions of the secondary Z-shaped structural unit 32 are based on the representative particle size in the hub working environment. d Determined. The representative particle size. d The median particle size of sediment particles in sand-laden water flow under the operating conditions can be designed for the hub body 2. d 50 can also be the particle size corresponding to the peak value of the particle size distribution. The energy dissipation stringer length of the secondary Z-shaped structural unit 32. l With the representative particle size d The ratio range satisfies 5≤ l / d ≤50. Through this proportional relationship, the secondary Z-shaped structural unit 32 can be matched with the main sediment particle size, thereby improving the dissipation efficiency of particle impact energy.

[0043] In some feasible implementations, the rigid support portion of the fractal Z-shaped structure 3, namely the primary contact crown surface 312 and the primary contact base saddle 313 of the primary Z-shaped structural unit 31, is made of, but is not limited to, metallic materials, hard alloy materials or wear-resistant composite materials, such as tungsten carbide composite materials, high-chromium cast iron or stainless steel-based wear-resistant composite materials.

[0044] In some feasible implementations, the secondary Z-shaped structural unit 32 can be made of polyurethane elastomer, rubber-based composite material, flexible metal material or tough composite material.

[0045] In some feasible implementations, each secondary Z-shaped structural unit 32 is a single-piece structure. The primary energy dissipation truss 311 of the primary Z-shaped structural unit 31 can also be a single-piece structure, for example, by 3D printing.

[0046] In some feasible implementations, multi-material 3D printing technology can be used to integrally mold the entire fractal Z-shaped structure 3, which not only achieves the distinction between rigid and flexible parts, but also ensures the integral reliability of the fractal Z-shaped structure 3.

[0047] In some feasible implementations, in addition to the aforementioned integral molding process, a split manufacturing and assembly process can also be used to manufacture the fractal Z-shaped structure 3. That is, the primary contact crown surface 312, the primary contact base saddle 313, and the primary energy dissipation truss 311 are manufactured separately and then assembled to form the primary Z-shaped structural unit 31. Specifically, the primary contact crown surface 312 and the primary contact base saddle 313, which are the rigid parts, can be first formed by precision casting, and then the primary energy dissipation truss 311, which is the flexible part, can be formed by secondary injection molding or insert molding processes. The connection methods between the first and second ends of the primary energy dissipation truss 311 and the primary contact crown surface 312 and the primary contact base saddle 313 include, but are not limited to, welding, bonding, and bolt fixing, which can be achieved using existing technologies.

[0048] During installation, the fractal Z-shaped structure 3 can be installed as an integral bushing on the surface of the hub body 2, or connected to the hub body 2 through welding or bonding processes. The fractal Z-shaped structure 3 is preferably arranged on the hub body 2 in the area adjacent to the suction surface inlet of the blade 4. This area is where particle impact and localized wear are concentrated after sand-laden water enters the impeller passage. For impellers with multiple blades 4, one or more fractal Z-shaped structures 3 can be set in the hub area corresponding to the suction surface inlet of each blade 4, ultimately forming a biomimetic wear-resistant hub structure.

[0049] The working principle of the above-mentioned biomimetic wear-resistant wheel hub structure is as follows: The external load first acts on the first-level contact crown surface 312 of the first-level Z-shaped structural unit 31, and then is transmitted and dissipated step by step through the first-level energy dissipation truss 311 composed of flexible second-level Z-shaped structural units 32. The energy dissipation is achieved through the following synergistic mechanism: the first-level contact crown surface 312 and the first-level contact base saddle 313 provide a rigid support foundation. At the same time, the first-level energy dissipation truss 311, based on the flexible design of the second-level Z-shaped structural unit 32, absorbs and dissipates the impact energy through its overall bending and torsional deformation, thus achieving large deformation energy dissipation.

[0050] Furthermore, the fractal Z-shaped structure 3 also possesses a fluid anti-wear mechanism: the biomimetic Z-shaped structural units (i.e., the first-level energy dissipation truss 311) continuously distributed across multiple scales in the fractal Z-shaped structure 3 can induce the fluid to form a multi-scale vortex structure in wear-prone areas. This vortex structure reduces wear in three synergistic ways: ① altering the particle trajectory to reduce direct impact and static accumulation of particles on the hub surface; ② reducing the impact kinetic energy of particles; ③ optimizing the particle impact angle to transform large-angle direct impacts into tangential rolling contact.

[0051] The fractal Z-shaped structure 3 of this invention, installed on the hub body 2, provides stable support through the rigid primary contact crown surface 312 and primary contact saddle 313 in the primary Z-shaped structural unit 31, and achieves gradual energy dissipation through the flexible secondary Z-shaped structural unit array, thus forming a multi-scale fractal structure with rigid-flexible coupling. This fractal structure can induce multi-scale vortices in the flow field, change the trajectory of sediment particles, reduce impact kinetic energy and optimize impact mode, and synergistically improve the wear resistance of the hub from the solid-liquid two-phase mechanical level. It is suitable for high-speed rotating mechanical impellers in sediment-containing fluid media.

[0052] For a centrifugal pump impeller hub (diameter 0.78m) using the biomimetic wear-resistant hub structure of this invention, the design length of the first-stage energy dissipation girder 311 in the first-stage Z-shaped structural unit 31 is... L The number of secondary Z-shaped structural units 32 in the primary energy dissipation truss 311 is 3.5mm. n The design length of the secondary energy dissipation truss 321 in each secondary Z-shaped structural unit 32 is equal to 10. l 0.35mm ( L / n The aforementioned α angle is approximately 23°, and the aforementioned β angle is approximately 50°. At a sand content of 5 kg / m³... 3 Under operating conditions, fluid dynamics simulation and wear analysis were used, and the results showed (compared to) Figure 11 and Figure 12 The centrifugal pump impeller using the biomimetic wear-resistant hub structure of the present invention has a significantly reduced wear area and a wear rate that can be reduced by 50%.

[0053] In summary, the fractal Z-shaped structure 3 of the present invention consists of a primary contact crown surface 312, a primary contact base saddle 313, and a primary energy dissipation truss 311 composed of multiple secondary Z-shaped structural units 32. In sediment-laden water flow, on the one hand, it withstands particle impact through rigid support and dissipates particle impact energy through multi-level structural deformation; on the other hand, it induces multi-scale vortices to change the particle motion mode, thereby significantly improving the wear resistance of the hub. Unlike existing wear-resistant structures, the present invention uses multiple secondary Z-shaped structural units 32 as micro-refinements of the primary energy dissipation truss 311, and arranges them through specific angles α and β. This multi-level fractal complex structure can more efficiently match the impact energy spectrum of sediment particles, achieving a synergistic wear resistance effect.

[0054] This invention has a clear structure and strong manufacturability, and can significantly reduce the wear rate of wheel hubs under sandy water flow conditions, thus extending the service life of the equipment. Comparative tests have verified the results; see the conclusions below. Figure 13 : Figure 13 As shown in the middle left figure (a), the surface of an ordinary wheel hub is smooth. Mud and sand particles directly impact the wear-prone area between the wheel hub body and the suction surface inlet of each blade. The trajectory of particles near the wall is relatively straight, and the local wear of the wheel hub is stronger. Figure 13 As shown in Figure (b) on the right, the biomimetic wear-resistant hub of the present invention has a fractal Z-shaped structure 3 between the hub body and the suction surface inlet of each blade. The fractal Z-shaped structure 3 dissipates the impact energy of the mud and sand particles through multi-stage deformation and induces local vortices to change the near-wall motion trajectory of the particles. After the trajectory is changed, some particles deviate from the hub and some rub against the hub at a low angle to form rolling or sliding, and the local wear of the hub is significantly reduced.

[0055] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0056] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A biomimetic wear-resistant wheel hub structure, characterized in that, The wheel hub includes a hub body and a fractal Z-shaped structure disposed on the surface of the hub body. The hub body has a wear-prone protection area adjacent to the inlet of the blade suction surface, and the fractal Z-shaped structure is disposed in the wear-prone protection area. The fractal Z-shaped structure includes a primary contact crown surface, a primary contact base saddle, and a primary energy dissipation truss. The primary contact crown surface and the primary contact base saddle are spaced apart. The primary energy dissipation truss is connected between the end of the primary contact crown surface and the beginning of the primary contact base saddle. The primary contact crown surface, the primary contact base saddle, and the primary energy dissipation truss together constitute a primary Z-shaped structural unit. The primary energy dissipation truss is composed of n secondary Z-shaped structural units connected in series in a tail-to-tail manner, where n is an integer greater than 1. Both the primary contact crown surface and the primary contact base saddle are rigid support components, while the primary energy dissipation truss is a flexible energy dissipation component.

2. The biomimetic wear-resistant wheel hub structure according to claim 1, characterized in that, The n secondary Z-shaped structural units constituting the primary energy dissipation truss have the same or similar Z-shaped topology and are arranged continuously along the extension direction of the primary energy dissipation truss. Each of the two-dimensional Z-shaped structural units includes a two-dimensional contact crown surface, a two-dimensional contact base saddle, and a two-dimensional energy dissipation truss. The secondary contact base saddle and the secondary contact crown surface are spaced apart, and the secondary energy dissipation truss is connected between the end of the secondary contact crown surface and the beginning of the secondary contact base saddle; Between any two adjacent secondary Z-shaped structural units, the end of the secondary contact saddle of the secondary Z-shaped structural unit closest to the starting end is connected to the starting end of the secondary contact crown surface of the next adjacent secondary Z-shaped structural unit.

3. The biomimetic wear-resistant wheel hub structure according to claim 2, characterized in that, In any of the first-order Z-shaped structural units described above: The first secondary Z-shaped structural unit located at the starting end of the primary energy dissipation truss has its secondary contact crown surface connected to the end of the primary contact crown surface, and the extension direction of the secondary contact crown surface and the primary contact crown surface form an angle β; the value of β ranges from 20° to 60°. The nth secondary Z-shaped structural unit located at the end of the primary energy dissipation truss has its secondary contact base saddle end connected to the starting end of the primary contact base saddle.

4. The biomimetic wear-resistant wheel hub structure according to claim 2 or 3, characterized in that, In any of the first-level Z-shaped structural units: the first-level contact crown surface and the first-level contact base saddle are parallel to each other, and the extension planes of the first-level contact crown surface and the first-level contact base saddle are both at an acute angle α to the surface of the wheel hub body; the value of α ranges from 10° to 30°. In any of the secondary Z-shaped structural units: the secondary contact crown surface and the secondary contact base saddle are parallel to each other.

5. The biomimetic wear-resistant wheel hub structure according to claim 2 or 3, characterized in that, The design length of the first-stage energy dissipation truss along its length direction is: L In each of the secondary Z-shaped structural units, the length of the secondary energy dissipation truss is... L / n The lengths of the secondary contact crown surface and the secondary contact base saddle are both L / (2n) .

6. The biomimetic wear-resistant wheel hub structure according to claim 2 or 3, characterized in that, In any of the first-order Z-shaped structural units described above: The first secondary Z-shaped structural unit located at the starting end of the primary energy dissipation truss has its starting end of the secondary energy dissipation truss coinciding with the starting end of the primary energy dissipation truss. The nth secondary Z-shaped structural unit located at the end of the primary energy dissipation truss has its secondary energy dissipation truss end coinciding with the end of the primary energy dissipation truss.

7. The biomimetic wear-resistant wheel hub structure according to claim 2 or 3, characterized in that, The secondary Z-shaped structural unit has topological similarity to the primary Z-shaped structural unit, and the overall size of the secondary Z-shaped structural unit is 1 / 5 to 1 / 20 of that of the primary Z-shaped structural unit.

8. The biomimetic wear-resistant wheel hub structure according to claim 2 or 3, characterized in that, In any of the two-dimensional Z-shaped structural units, the design length of the two-dimensional energy dissipation truss along its length direction is: l The representative particle size of the sediment particles in the sand-laden water flow under the designed operating conditions of the hub body is: d , d Median particle size d 50 or the particle size corresponding to the peak value of the particle size distribution; l and d The ratio range is 5≤ l / d ≤50.

9. The biomimetic wear-resistant wheel hub structure according to any one of claims 1-3, characterized in that, Both the primary contact crown surface and the primary contact base saddle are made of materials with high elastic modulus and high wear resistance; each of the secondary Z-shaped structural units is made of materials with high fatigue strength and high toughness.

10. A centrifugal pump impeller, characterized in that, The device includes the biomimetic wear-resistant hub structure as described in any one of claims 1 to 9 and a plurality of blades, wherein the plurality of blades are arranged at circumferential intervals along the hub body and are connected to the hub body; the area adjacent to the hub body at the suction surface inlet of each blade is the wear-prone protection area, and each wear-prone protection area is provided with the fractal Z-shaped structure.

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