Combined locking nut structure and pump

Abstract

The utility model discloses a combined locking nut structure and a pump, the combined locking nut structure is used for preventing a hub mounted on a shaft body from loosening, the combined locking nut structure comprises an inner nut and an outer nut, the inner surface of the inner nut is provided with a first inner thread, one end of the inner nut abuts against the hub, and the outer surface of the inner nut is provided with a first outer thread; a second internal thread matched with the first external thread is arranged on the inner surface of the outer nut; a first matching part is arranged at the end, away from the hub, of the inner nut, a second matching part is arranged at the end, away from the hub, of the outer nut, the second matching part and the first matching part are matched to form an anti-loosening mechanism, and after the combined locking nut structure is assembled, the second matching part applies inward radial pressure to the first matching part. On the premise that the axial installation space is not increased, reliable fixing of the hub can be achieved through the anti-loosening design of the combined locking nut structure, irreversible damage to the shaft body is avoided, meanwhile, the equipment maintenance convenience is improved, and the overall service life is prolonged.

Description

Technical Field

[0001] This utility model relates to a combination locking nut structure and pump for preventing loosening, and particularly to a combination locking nut structure and pump for fixing and preventing loosening of the shaft and hub. Background Technology

[0002] In the petrochemical industry's production processes, the BB2 two-stage pump is a critical fluid transport device, and its operational stability directly affects the continuity and safety of production. The secondary impeller of this type of pump generally adopts a tapered shaft bore fit structure. The tapered shaft bore fit is widely used in impeller assembly due to its high centering accuracy and strong load-bearing capacity.

[0003] However, impellers using tapered shaft bore fittings require extremely high reliability in terms of fixing and anti-loosening methods. If the fixing and anti-loosening measures are inadequate, the impeller is prone to loosening during high-speed operation, directly leading to abnormal equipment operation, and even causing equipment failure and production safety issues.

[0004] Currently, the industry's methods for fixing impellers with tapered shaft holes are relatively simple. Usually, a single nut is used to lock and position the impeller, and the anti-loosening effect is enhanced by drilling anti-rotation pin holes on the shaft or directly pressing the anti-rotation pins against the threaded surface of the shaft to prevent relative rotation or axial movement of the impeller during operation.

[0005] The aforementioned traditional anti-loosening methods have several drawbacks: Firstly, during the assembly of the anti-rotation pins, the machining of the pin holes causes irreversible mechanical damage to the shaft itself, compromising its structural integrity. The direct contact between the pin and the shaft threads also causes irreversible mechanical damage to the threads, thus reducing the shaft's load-bearing capacity and service life. Secondly, during equipment maintenance, when the user needs to replace the secondary impeller, the new impeller's tapered hole size is limited by machining precision, resulting in a certain error. This causes a deviation between the axial positioning of the new impeller and the original impeller, rendering the anti-rotation pin holes originally drilled to fit the old impeller unusable. In this case, new anti-rotation pin holes need to be drilled on the shaft to accommodate the new impeller's positioning. This further exacerbates the damage to the shaft, continuously reducing its strength and service life, and posing a potential threat to the long-term stable operation of the equipment.

[0006] In summary, for impellers using tapered shaft hole fittings, there is an urgent need to propose a novel combined locking nut structure to meet their high reliability requirements for fixing and preventing loosening.

[0007] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Utility Model Content

[0008] In order to overcome the above-mentioned defects of the prior art, the present invention provides a combined locking nut structure and a pump, which can reliably fix the hub through the anti-loosening design of the combined locking nut structure without increasing the axial installation space, avoid irreversible damage to the shaft, and improve the convenience of equipment maintenance and the overall service life.

[0009] The specific technical solution of this utility model embodiment is as follows:

[0010] A combined locking nut structure is provided to prevent a wheel hub mounted on a shaft from loosening. The combined locking nut structure includes an inner nut and an outer nut. The inner surface of the inner nut has a first internal thread for engaging with the threaded shaft. One end of the inner nut abuts against the wheel hub. The outer surface of the inner nut has a first external thread for engaging with the outer nut. The inner surface of the outer nut has a second internal thread for engaging with the first external thread of the inner nut. The inner nut has a first mating portion at the end facing away from the wheel hub. The outer diameter of the mating part gradually decreases as the distance from the hub increases, so that the first mating part forms a wedge-shaped surface with a first cone angle on the outer surface of the inner nut. The outer nut is provided with a second mating part at the end away from the hub. The inner diameter of the second mating part gradually decreases as the distance from the hub increases, so that the inner surface of the second mating part forms a wedge-shaped surface with a second cone angle. The second mating part and the first mating part cooperate to form an anti-loosening mechanism. When the combined locking nut structure is assembled, the second mating part applies an inward radial pressure to the first mating part.

[0011] In a preferred embodiment, the second cone angle is greater than or equal to the first cone angle; after the combined locking nut structure is assembled, the second mating part applies an inward radial pressure and an axial pressure toward the hub to the first mating part.

[0012] In a preferred embodiment, the first cone angle is between 15° and 30°.

[0013] In a preferred embodiment, the second mating part is provided with a fastening hole that penetrates the side wall of the outer nut, and the combined locking nut structure further includes a fastener, which is installed in the fastening hole and abuts against the first mating part.

[0014] In a preferred embodiment, the axial direction of the fastening hole is perpendicular to the wedge-shaped surface of the first mating part. When the combined locking nut structure is assembled, the fastener applies an inward radial pressure to the first mating part and an axial pressure toward the hub.

[0015] In a preferred embodiment, there are multiple fastening holes, which are evenly spaced along the circumference of the outer nut, and the number of fasteners matches the number of fastening holes.

[0016] In a preferred embodiment, the inner nut is provided with a locking groove at the first mating part position. The locking groove extends axially from the end of the inner nut away from the hub and close to the hub side, and passes through the first mating part in the radial direction, so that the first mating part forms a cantilever structure, which facilitates deformation under the radial pressure of the second mating part.

[0017] In a preferred embodiment, the width of the locking groove is between 0.6 mm and 3 mm.

[0018] In a preferred embodiment, the outer surface of the inner nut is provided with a first disassembly portion, and / or the outer surface of the outer nut is provided with a second disassembly portion.

[0019] A pump comprising: any of the above-described combined locking nut structures; a hub, the hub being an impeller; a shaft having a tapered section; the impeller having a tapered hole adapted to fit the shaft, the impeller being sleeved on the tapered shaft of the shaft, and the smaller end of the tapered hole of the impeller being axially limited by the combined locking nut structure mounted on the shaft.

[0020] The technical solution of this utility model has the following significant beneficial effects:

[0021] The combined locking nut structure provided in this application embodiment adopts a double-layer structure with an inner nut and an outer nut superimposed and engaged. The inner nut serves as the basic component for impeller fixing, with its first internal thread directly engaging with the shaft thread, and its end abutting against the hub to achieve axial restraint. The first external thread on its outer surface engages with the second internal thread of the outer nut, forming a double-layer threaded connection. The inner nut has a first mating portion away from the impeller end, and the corresponding end of the outer nut has a second mating portion. When the outer nut is tightened, the second mating portion applies at least radial pressure to the first mating portion, forming an anti-loosening structure.

[0022] The double-layer structure, featuring an inner and outer nut, provides more stable support than a single nut without increasing axial space, thus solving the problem of weak vibration resistance in traditional single-nut systems. The pressure transmission between the first and second mating parts overcomes the limitations of traditional methods relying solely on thread friction for anti-loosening. By applying additional radial pressure, the fit between the inner nut's first internal thread and the shaft thread is significantly improved, enhancing anti-loosening reliability compared to existing technologies. The direct contact between the inner nut and the impeller avoids the need for pin hole machining on the shaft, fundamentally eliminating the risk of shaft structural damage and greatly extending shaft lifespan. Overall, the combined locking nut structure is simple, easy to disassemble, and facilitates convenient equipment maintenance. Attached Figure Description

[0023] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, under the guidance of this invention, can select various possible shapes and proportions to implement this invention according to specific circumstances.

[0024] Figure 1 This is a diagram showing the relative position of a combined locking nut structure installed on the shaft and the impeller in an embodiment of this utility model.

[0025] Figure 2 This is a schematic diagram of a combined locking nut structure according to an embodiment of the present utility model;

[0026] Figure 3 This is a schematic diagram of the inner nut of a combined locking nut structure according to an embodiment of the present utility model;

[0027] Figure 4 This is a schematic diagram of the outer nut of a combined locking nut structure according to an embodiment of the present utility model;

[0028] Figure 5 This is a schematic diagram illustrating the fit of a combined locking nut structure according to an embodiment of the present invention.

[0029] The reference numerals in the above figures are as follows:

[0030] 100. Shaft body;

[0031] 200. Impeller;

[0032] 300. Combined locking nut structure;

[0033] 310. Inner nut;

[0034] 311. First internal thread;

[0035] 312. First external thread;

[0036] 313. First disassembly section;

[0037] 314. Locking groove;

[0038] 315. First Coordination Department;

[0039] 320. External nut;

[0040] 321. Fastening hole;

[0041] 322. Second internal thread;

[0042] 323. Second disassembly section;

[0043] 325. Second Coordination Unit;

[0044] 330. Fasteners. Detailed Implementation

[0045] The details of this utility model can be more clearly understood by referring to the accompanying drawings and the description of specific embodiments. However, the specific embodiments of this utility model described herein are for illustrative purposes only and should not be construed as limiting the utility model in any way. Under the teachings of this utility model, those skilled in the art can conceive of any possible modifications based on this utility model, and these should all be considered to fall within the scope of this utility model.

[0046] To address the problems of severe shaft damage, poor anti-loosening reliability, and weak maintenance adaptability in existing tapered shaft hole impeller fixing methods, this utility model provides a combined locking nut structure and pump. Without increasing the axial installation space, the anti-loosening design of the combined locking nut structure achieves reliable hub fixing, avoids irreversible shaft damage, and improves equipment maintenance convenience and overall service life.

[0047] Please refer to the following for comprehensive information. Figures 1 to 4 This application specification provides a combined locking nut structure 300 to prevent a hub mounted on a shaft 100 from loosening. Specifically, the hub can be an impeller 200. Of course, the hub can also be other shaft-mounted rotating bodies. In this application embodiment, the impeller 200 is mainly used as an example for illustration. Other forms of shaft-mounted rotating bodies can be simply replaced with the impeller 200, and will not be described in detail here.

[0048] The combined locking nut structure 300 may include: an inner nut 310 and an outer nut 320. The inner surface of the inner nut 310 is provided with a first internal thread 311, which is used to thread into the shaft 100. One end of the inner nut 310 abuts against the impeller 200. The outer surface of the inner nut 310 is provided with a first external thread 312 for engaging with the outer nut 320. The inner surface of the outer nut 320 is provided with a second internal thread 322 for engaging with the first external thread 312 of the inner nut 310. The inner nut 310 has a first mating part 315 at the end opposite to the impeller 200, and the outer nut 320 has a second mating part 325 at the end opposite to the impeller 200. The second mating part 325 and the first mating part 315 cooperate to form an anti-loosening mechanism. When the combined locking nut structure is assembled, the second mating part 325 applies an inward radial pressure to the first mating part 315.

[0049] The combined locking nut structure 300 provided in this application embodiment adopts a double-layer structure with an inner nut 310 and an outer nut 320 superimposed and engaged, wherein, as Figure 2 and Figure 3 As shown, the inner nut 310 serves as the basic component for fixing the impeller 200. Its inner surface has a first internal thread 311 that directly engages with the shaft 100 thread, and its end abuts against the impeller 200 to achieve axial positioning. The outer surface has a first external thread 312 that engages with the second internal thread 322 of the outer nut 320, forming a double-threaded connection. The inner nut 310 has a first mating part 315 at the end facing away from the impeller 200, such as... Figure 4 As shown, the outer nut 320 has a second mating part 325 at the corresponding end. When the outer nut 320 is tightened, the second mating part 325 applies radial pressure to the first mating part 315 to form an anti-loosening structure.

[0050] Because of the double-layer structure of the inner nut 310 and the outer nut 320, the axial space is not increased, and the double-layer threaded engagement forms a more stable support than a single nut, solving the problem of weak vibration resistance of traditional single nuts. The pressure transmission between the first mating part 315 and the second mating part 325 breaks through the limitation of traditional anti-loosening relying solely on thread friction. By applying additional radial pressure, the fit between the first internal thread 311 of the inner nut 310 and the thread of the shaft 100 is significantly improved, and the anti-loosening reliability is improved compared with the existing technology. The positioning method of the inner nut 310 directly abutting against the impeller 200 avoids the need to machine pin holes in the shaft 100, fundamentally eliminating the risk of structural damage to the shaft 100 and greatly extending the service life of the shaft 100. Overall, the combined locking nut structure 300 has a simple structure and is easy to disassemble, which helps to ensure the convenience of equipment maintenance.

[0051] In one embodiment, the outer diameter of the first mating part 315 gradually decreases as the distance from the impeller 200 increases, so that the first mating part 315 forms a wedge-shaped surface with a first cone angle on the outer surface of the inner nut 310; the inner diameter of the second mating part 325 gradually decreases as the distance from the impeller 200 increases, so that the inner surface of the second mating part 325 forms a wedge-shaped surface with a second cone angle, the second cone angle being greater than or equal to the first cone angle; when the combined locking nut structure is assembled, the second mating part 325 applies an inward radial pressure and an axial pressure toward the impeller 200 to the first mating part 315.

[0052] In this embodiment, the first mating part 315 and the second mating part 325 can specifically be a wedge-shaped surface structure with a cone angle. The wedge-shaped surface formed by the reduced diameter section can efficiently convert the torque when the outer nut 320 is tightened into axial pressure and radial pressure. The axial pressure directly pushes the inner nut 310 to press against the impeller 200 side, and the radial pressure causes the inner nut 310 to undergo slight contraction deformation, further strengthening the meshing depth between the first internal thread 311 and the thread of the shaft 100, thus solving the defect of traditional nuts that only axially press and have insufficient thread fit.

[0053] The second cone angle is greater than or equal to the first cone angle, which is used to ensure that the wedge-shaped surface of the outer nut 320 can fit the wedge-shaped surface of the inner nut 310, making the pressure transmission more uniform and improving the long-term stability of the structure. In addition, the wedge-shaped surface mating structure has self-tightening characteristics. The vibration generated by the pump body operation will cause the outer nut 320 to tighten further rather than loosen, which completely solves the problem of easy failure of traditional anti-loosening structures due to vibration.

[0054] Specifically, the first cone angle is between 15° and 30°.

[0055] Considering the limited axial space for the installation of this combination locking nut structure, if the first cone angle is too small, for example, less than 15°, the threads of the inner nut 310 and the outer nut 320 will not be able to be arranged properly, or the number of threads will be too small, resulting in unreliable tightening of the inner and outer nuts.

[0056] If the second cone angle is too large, for example, greater than 30°, when tightening the outer nut 320, the cone surface of the inner nut 310 away from the impeller 200 will not easily undergo elastic deformation, which will cause the inner nut 310 to fail to reliably fit tightly with the shaft 100.

[0057] In one embodiment, the second mating part 325 is provided with a fastening hole 321 that passes through the side wall of the outer nut 320. The combined locking nut structure 300 also includes a fastener 330, which is installed in the fastening hole 321, and the end of the fastener 330 abuts against the first mating part 315.

[0058] In this embodiment, to further enhance the anti-loosening effect, the outer nut 320 is provided with a fastening hole 321 and a matching fastener 330. The end of the fastener 330 abuts against the first mating part 315, forming a triple fixation of threaded engagement + wedge surface pressure + fastener 330 tightening, which greatly improves the reliability compared to the traditional single anti-loosening structure. The fastener 330 avoids the damage to the shaft 100 caused by the traditional pin. It acts on the mating part of the inner nut 310 rather than the shaft 100. When replacing the impeller 200, only the fastener 330 needs to be removed, without any machining of the shaft 100. The threaded engagement between the fastener 330 and the fastening hole 321 facilitates individual disassembly and maintenance. If the fastener 330 is worn, it can be directly replaced without scrapping the entire nut structure, reducing maintenance costs.

[0059] Furthermore, the axial direction of the fastening hole 321 is perpendicular to the wedge-shaped surface of the first mating part 315, and the fastener 330 can apply inward radial pressure and axial pressure toward the impeller 200 to the first mating part 315.

[0060] When the axial direction of the fastening hole 321 is perpendicular to the wedge-shaped surface of the first mating part 315, it helps to maximize pressure transmission. Specifically, the pressure in this vertical direction can be decomposed into a normal pressure that fits against the wedge-shaped surface, so that the pressure is fully applied to the first mating part 315 of the inner nut 310, avoiding component force loss. This achieves a better anti-loosening effect than a non-vertical design. Vertical tightening can simultaneously enhance the shrinkage deformation and axial clamping effect of the inner nut 310, making the meshing of the first internal thread 311 and the thread of the shaft 100 tighter, reducing vibration wear caused by thread clearance. This angle design makes the force direction of the fastener 330 have a certain angle with the centrifugal force generated by the pump body operation, avoiding the influence of centrifugal force on the stability of the fastener 330 and ensuring that it will not loosen during long-term use.

[0061] like Figure 5 As shown, the axial direction θ of the fastening hole 321 can also form a certain angle with the wedge-shaped surface of the first mating part 315. The axial direction θ of the fastening hole 321 can be located within the upper left 90° range formed by the vertical plane Y and the horizontal plane X. When the axial direction θ of the fastening hole 321 is located between the direction perpendicular to the wedge-shaped surface of the first mating part 315 and the horizontal plane X, the pressure applied by the fastener 330 can be more decomposed into axial pressure applied to the first mating part 315 towards the impeller 200, thereby achieving a more relaxed effect in the axial direction.

[0062] Specifically, there are multiple fastening holes 321, which are evenly spaced along the circumference of the outer nut 320, and the number of fasteners 330 is matched with the number of fastening holes 321.

[0063] In this embodiment, when the fastening holes 321 and fasteners 330 are evenly distributed along the circumference of the outer nut 320, the radial pressure on the mating part of the inner nut 310 is evenly distributed in a ring, preventing deformation or cracking of the inner nut 310 due to excessive local pressure, thus extending the nut's service life. Specifically, the number of fastening holes 321 can be 2-4, for example, 3. The number of fasteners 330 can also be 3. The configuration of multiple fasteners 330 forms a redundancy against loosening; even if one fastener 330 fails, the remaining fasteners 330 can still maintain a basic anti-loosening effect, reducing the risk of sudden failure.

[0064] Specifically, the fastener 330 can be a screw, and the fastening hole 321 can be a threaded hole. Of course, the specific forms of the fastener 330 and the fastening hole 321 are not limited to those described above. Those skilled in the art, inspired by the technical essence of this application, may make other modifications, but as long as their functions and effects are the same as or similar to those of this application, they should all be covered within the scope of protection of this application.

[0065] In one embodiment, the inner nut 310 is provided with a locking groove 314 at the first mating part 315, and the locking groove 314 extends axially from the end of the inner nut 310 away from the impeller 200 towards the side close to the impeller 200.

[0066] In this embodiment, by opening a locking groove 314 at one end and extending through the wall thickness of the inner nut 310 in the first mating portion 315, the structural rigidity of the inner nut 310 at the first mating portion 315 can be reduced. This allows the inner nut 310 to undergo controllable slight contraction deformation along the locking groove 314 when pressure is applied by the outer nut 320. This deformation better matches the profile of the thread on the shaft 100, and the elastic stress generated by the deformation further strengthens the friction between the threads, forming a combined effect of rigid fixation and elastic pre-tightening, thus improving the long-term effectiveness of anti-loosening. In addition, the axial length of the locking groove 314 is less than the length of the first mating portion 315, which avoids overall deformation of the inner nut 310, thus affecting the stability of its contact with the impeller 200.

[0067] The width of the locking groove 314 is between 0.6 mm and 3 mm.

[0068] When the width of the locking groove 314 is less than 0.6 mm, its deformation capacity is insufficient, and the threads cannot be fully engaged. When the groove width is greater than 3 mm, the structural strength of the mating part of the inner nut 310 will be significantly reduced. However, when the width of the locking groove 314 is between 0.6 and 3 mm, it matches the conventional wall thickness of the inner nut 310, ensuring the deformation requirements while maintaining the load-bearing capacity of the inner nut 310, thus meeting the axial load requirements of the BB2 two-stage pump impeller 200. Furthermore, when the width of the locking groove 314 is between 0.6 mm and 3 mm, specifically around 1 mm, existing conventional machining methods (such as wire cutting) can be used to efficiently, conveniently, and cost-effectively machine the locking groove 314.

[0069] In one embodiment, the outer surface of the inner nut 310 is provided with a first disassembly portion 313, and / or the outer surface of the outer nut 320 is provided with a second disassembly portion 323.

[0070] In this embodiment, the outer surface of the inner nut 310 may be provided with a first disassembly portion 313, which may specifically be a groove provided along the axial direction on the outer surface of the inner nut 310. The outer surface of the outer nut 320 may be provided with a second disassembly portion 323, which may specifically be a groove provided along the axial direction on the outer surface of the outer nut 320. By providing the above-mentioned grooves, operators can quickly complete tightening or disassembly using standard tools, improving maintenance efficiency; at the same time, it can avoid scratches on the outer surface of the nut caused by traditional wrench clamping, protecting the nut's precision; in addition, the inner and outer nuts 320 are each provided with disassembly portions, which can be operated independently. For example, when replacing the outer nut 320, it is not necessary to disassemble the inner nut 310 and the impeller 200, further improving maintenance flexibility and reducing downtime.

[0071] There can be multiple first disassembly parts 313, which can be evenly distributed along the circumference of the inner nut 310. This allows operators to quickly engage the appropriate disassembly part without precisely aligning the wrench within the confined space inside the pump body, accommodating different operating angles. At the same time, the evenly distributed grooves can distribute the force of the hook wrench to multiple points on the circumference of the inner nut 310, preventing groove deformation caused by excessive torque at a single point of force application. This further protects the structural integrity of the nut, and can effectively improve operational safety and nut lifespan, especially when large torque is required for tightening or disassembly.

[0072] There can be multiple second disassembly parts 323, and the multiple second disassembly parts 323 can be evenly distributed along the circumference of the outer nut 320. The technical effect of the multiple second disassembly parts 323 can refer to the technical effect of the multiple first disassembly parts 313 mentioned above, and will not be repeated here.

[0073] This application also provides a pump, the pump comprising: the combined locking nut structure 300 described in any of the above embodiments; a shaft 100, the shaft 100 being a tapered shaft; an impeller 200, the impeller 200 having a tapered hole adapted to the shaft 100, the impeller 200 being sleeved on the shaft 100, and one side of the impeller 200 being axially limited by the combined locking nut structure 300 mounted on the shaft 100.

[0074] Overall, the pump provided in this application embodiment has an adaptive structure consisting of a conical shaft 100, a conical impeller 200, and a combination locking nut. This significantly improves the positioning accuracy of the impeller 200, reduces eccentric vibration during operation, and lowers pump noise. The combination locking nut prevents damage to the shaft 100, extending the service life of the pump's core components (shaft 100 and impeller 200) and reducing equipment failure rate. This structure is more adaptable to machining errors in the conical hole of the impeller 200, and no adjustment to the shaft 100 structure is required when installing a new impeller 200, shortening equipment maintenance time. It is particularly suitable for the continuous production needs of the petrochemical industry. The overall structural reliability improves the pump's operating efficiency and prevents efficiency loss due to impeller 200 loosening.

[0075] In a specific application scenario, taking the BB2 two-stage pump as an example, the pump shaft 100 is a tapered shaft with a predetermined taper, for example, a taper of 1:10. The impeller 200 is a secondary impeller 200, and the middle of the impeller 200 has a tapered hole with a taper that matches the shaft 100, for example, the tapered section is also 1:10. The combined locking nut structure 300 adopts a through-shaft design and is installed on the threaded section of the shaft 100. The end of the inner nut 310 abuts against the side of the impeller 200, and the outer nut 320 is screwed onto the outside of the inner nut 310. The fastener 330 tightens the first mating part 315 of the inner nut 310 through the fastening hole 321.

[0076] The combined locking nut structure 300 provided in this application embodiment, for the application scenario of installing the middle section of the BB2 two-stage pump shaft, has the following technical effects: First, addressing the core pain point of limited space in the middle section of the pump shaft, this structure, through the integrated layout of the inner nut 310-outer nut 320 stacked and the through-shaft design, strictly controls the axial length to within 45mm and the radial thickness on one side not exceeding 25mm, perfectly adapting to the narrow installation space of the middle section of the shaft and avoiding interference with the pump body housing and other surrounding components; Second, due to the closed structure, the existing technology can only be applied to the shaft end, completely failing to meet the usage requirements of fixing the middle section of the shaft of this product; Furthermore, under the strict space constraints, this structure still retains the complete anti-loosening system of double-layer thread + wedge surface + fastener 330, without sacrificing anti-loosening performance due to space compression, achieving the dual goals of small space + high reliability, filling the technical gap of fixing the conical shaft hole impeller 200 in the middle section of the pump shaft, making the structural design of the BB2 two-stage pump more flexible, without needing to additionally expand the internal space of the pump body to adapt to the locking structure, thus reducing the overall manufacturing cost of the pump body.

[0077] All articles and references disclosed herein, including patent applications and publications, are incorporated herein by reference for various purposes. The term “substantially constitutes…” used to describe a combination should include the identified element, component, part, or step, as well as other elements, components, parts, or steps that do not substantially affect the essential novelty of the combination. The use of the terms “comprising” or “including” to describe combinations of elements, components, parts, or steps herein also contemplates embodiments substantially constituted by such elements, components, parts, or steps. The use of the term “may” herein is intended to indicate that any described attribute “may” include is optional. Multiple elements, components, parts, or steps can be provided by a single integrated element, component, part, or step. Alternatively, a single integrated element, component, part, or step can be divided into multiple separate elements, components, parts, or steps. The disclosure of “a” or “an” used to describe an element, component, part, or step does not imply exclusion of other elements, components, parts, or steps.

[0078] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.

Claims

1. A combined locking nut structure for preventing a hub mounted on a shaft from loosening, characterized in that, The combined locking nut structure includes: an inner nut and an outer nut. The inner surface of the inner nut is provided with a first internal thread, which is used to engage with the shaft thread. One end of the inner nut abuts against the hub, and the outer surface of the inner nut is provided with a first external thread for engaging with the outer nut. The inner surface of the outer nut is provided with a second internal thread for engaging with the first external thread of the inner nut; The inner nut has a first mating part at the end opposite to the hub. The outer diameter of the first mating part gradually decreases as the distance from the hub increases, so that the first mating part forms a wedge-shaped surface with a first cone angle on the outer surface of the inner nut. The outer nut has a second mating part at the end opposite to the hub. The inner diameter of the second mating part gradually decreases as the distance from the hub increases, so that the inner surface of the second mating part forms a wedge-shaped surface with a second cone angle. The second mating part and the first mating part cooperate to form an anti-loosening mechanism. When the combined locking nut structure is assembled, the second mating part applies an inward radial pressure to the first mating part.

2. The combined locking nut structure according to claim 1, characterized in that, The second cone angle is greater than or equal to the first cone angle; After the combined locking nut structure is assembled, the second mating part applies an inward radial pressure and an axial pressure toward the hub to the first mating part.

3. The combined locking nut structure according to claim 2, characterized in that, The first cone angle is between 15° and 30°.

4. The combined locking nut structure according to claim 2, characterized in that, The second mating part is provided with a fastening hole that passes through the side wall of the outer nut. The combined locking nut structure also includes a fastener, which is installed in the fastening hole and abuts against the first mating part.

5. The combined locking nut structure according to claim 4, characterized in that, The axial direction of the fastening hole is perpendicular to the wedge-shaped surface of the first mating part. When the combined locking nut structure is assembled, the fastener applies inward radial pressure and axial pressure toward the hub to the first mating part.

6. The combined locking nut structure according to claim 4, characterized in that, The number of fastening holes is multiple, and the multiple fastening holes are evenly distributed along the circumference of the outer nut. The number of fasteners is adapted to the number of fastening holes.

7. The combined locking nut structure according to claim 1, characterized in that, The inner nut has a locking groove at the first mating part. The locking groove extends axially from the end of the inner nut away from the hub and passes through the first mating part in the radial direction, so that the first mating part forms a cantilever structure, which facilitates deformation under the radial pressure of the second mating part.

8. The combined locking nut structure according to claim 7, characterized in that, The width of the locking groove is between 0.6 mm and 3 mm.

9. The combined locking nut structure according to claim 1, characterized in that, The outer surface of the inner nut is provided with a first disassembly portion, and / or the outer surface of the outer nut is provided with a second disassembly portion.

10. A pump, characterized in that, The pump includes: The combined locking nut structure as described in any one of claims 1 to 9; The hub is an impeller; A shaft having a tapered section; The impeller is provided with a tapered hole for fitting with the shaft body. The impeller is sleeved on the tapered shaft of the shaft body. The small end of the tapered hole of the impeller is axially limited by a locking nut structure installed on the shaft body.

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