Water inlet ball valve ball structure

Abstract

The utility model relates to ball valve technical field, and disclose water inlet ball valve ball structure, solved the problem in the background art, including the ball main part, axle end connecting part, seat ring and back muscle board, axle end connecting part and seat ring adopt taper surface cooperation structure, the taper surface has continuous transition curved surface, seat ring and back muscle board junction adopt arc transition structure, the utility model discloses the ball structure of improvement, from the weldability, greatly reduces the welding area, reduces the quantity of stress concentration, also makes nondestructive testing more convenient, from foundry, simple structure also improves the foundry workability, and the mould production is also facilitated a lot, therefore, the new structure has very big promotion space.

Description

Technical Field

[0001] This utility model belongs to the field of ball valve technology, specifically the ball structure of an inlet ball valve. Background Technology

[0002] The inlet ball valve is installed on the pressure steel pipe at the inlet section of the volute casing. Its main function is to cut off the water flow and ensure the safety of the generator unit when the turbine malfunctions. Applications include gravity-fed hydropower, pumped-storage hydropower, and pipeline water transport. These applications typically involve high water head, large diameter, and high pressure. The ball, as the most critical component of the ball valve, directly affects the valve's lifespan and can even jeopardize the safety of the entire unit. To improve the stress distribution on the ball and considering various application scenarios, this patent proposes a unique solution from a structural perspective.

[0003] The conventional structure of ball valve balls often uses a multi-rib connection between the shaft end and the seat ring. This structure suffers from significant stress concentration due to the large torsional force during frequent opening and closing and the large axial force transmitted during closing, making dimensional control difficult during manufacturing. The connection between the seat ring and the back rib plate is also problematic in terms of manufacturability, often resulting in a difficult-to-smooth transition and an unattractive appearance. While a grid-like structure is commonly used for the back rib plate to ensure the rigidity of the ball, it is overly complex and inconvenient for casting or welding. Therefore, a new inlet ball valve structure is proposed. Utility Model Content

[0004] To solve the above problems, this utility model provides the following technical solution: a ball structure for an inlet ball valve, including a ball body, a shaft end connecting part, a seat ring, and a back rib plate. The shaft end connecting part and the seat ring adopt a conical surface mating structure, and the conical surface has a continuous transition curved surface. The connection between the seat ring and the back rib plate adopts an arc transition structure.

[0005] Furthermore, the radius of curvature of the back rib is proportional to the outer diameter of the seat ring by 0.8-1.2 times, and the radius of the transition arc is not less than 1 / 3 of the thickness of the seat ring; the thickness of the back rib decreases in a gradient along the radial direction, with the maximum thickness area located at the seat ring connection, and its thickness value is 0.6-0.8 times the thickness of the seat ring.

[0006] Furthermore, the thickness gradient of the back rib plate decreases at an angle of 3°-5°, and the thickness decreases by 5-8mm for every 100mm of radial extension.

[0007] Furthermore, the cone angle of the conical mating structure is 70°-80°, and the axial projection length of the conical surface is not less than 1.2 times the journal diameter.

[0008] Compared with the prior art, the beneficial effects of this utility model are:

[0009] In terms of weldability, this invention significantly reduces the number of welding areas and stress concentrations in the improved spherical structure, making non-destructive testing more convenient. In terms of castability, the simple structure also improves the casting process and makes mold making much easier. Therefore, the new structure has great potential for improvement. Attached Figure Description

[0010] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0011] Figure 1 This is a schematic diagram of the structure of a ball valve ball in the prior art;

[0012] Figure 2 This is a three-dimensional structural diagram of the entire utility model;

[0013] Figure 3 This is a schematic diagram of static analysis using existing technology;

[0014] Figure 4 This is a schematic diagram of the static analysis of this utility model;

[0015] In the diagram: 1. Main body of the sphere; 2. Shaft end connection; 3. Seat ring; 4. Back rib plate. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0017] Depend on Figure 2 As shown, this utility model includes a sphere body 1, a shaft end connecting part 2, a seat ring 3, and a back stiffener 4. The shaft end connecting part 2 and the seat ring 3 adopt a conical surface mating structure, and the conical surface has a continuous transition curved surface; the connection between the seat ring 3 and the back stiffener 4 adopts an arc transition structure.

[0018] The radius of curvature of the back stiffener 4 is proportional to the outer diameter of the seat ring 3 by 0.8-1.2 times, and the radius of the transition arc is not less than 1 / 3 of the seat ring thickness. The thickness of the back stiffener 4 decreases radially, with the maximum thickness area located at the connection of the seat ring 3, where the thickness is 0.6-0.8 times the seat ring thickness. The spherical stiffener is concentrically designed with the seat ring, allowing the load to be naturally distributed along the curved surface, reducing bending stress. The curvature ratio range (0.8-1.2 times) ensures the geometric matching between the stiffener and the seat ring, while avoiding manufacturing difficulties due to excessive curvature or weakening the support strength due to insufficient curvature. The arc transition eliminates the sharp corners at traditional right-angle connections, smooths the stress transmission path, and prevents fatigue crack initiation. The minimum radius limit (≥1 / 3 of the seat ring thickness) ensures that the transition area has sufficient cross-sectional area to withstand alternating loads and extends service life.

[0019] The thickness gradient of the back stiffener 4 decreases at an angle of 3°-5°, with a decrease of 5-8mm every 100mm along the radial direction. The 3°-5° decrease angle controls the smoothness of the thickness change and avoids stress concentration caused by abrupt changes. The rate of decrease of 5-8mm every 100mm matches the filling capacity of the casting / welding process, taking into account both structural strength and manufacturing feasibility, and reducing the difficulty of the process.

[0020] The cone angle of the conical mating structure is 70°-80°, and the axial projection length of the cone surface is not less than 1.2 times the journal diameter. The cone angle of 70°-80° optimizes the decomposition ratio of axial force and radial force, ensuring that the axial thrust is effectively converted into the clamping force of the seat ring when the valve is closed. The axial projection length is ≥1.2 times the journal diameter, ensuring that the contact area of ​​the cone surface is large enough to prevent local overpressure deformation.

[0021] For ease of comparison, finite element analysis was performed on the existing technical structure and the structure in the embodiment of this utility model, and the comparison results are as follows: Figure 3 , Figure 4 Analyze the overall force situation of the sphere. Figure 3 Stress concentration is very obvious in the middle, and Figure 4 The stress value is significantly reduced; data analysis shows that the improved stress is less than half of the previous value, the stress distribution is more uniform, and the structure is more rational.

[0022] In terms of weldability, the improved spherical structure greatly reduces the number of welding areas and stress concentrations, making non-destructive testing more convenient. In terms of castability, the simple structure also improves the casting process and makes mold making much easier. Therefore, the new structure has great potential for improvement.

[0023] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0024] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A water inlet ball valve ball structure, comprising a ball body (1), a shaft end connecting part (2), a seat ring (3) and a back rib plate (4), characterized in that: The shaft end connecting part (2) and the seat ring (3) adopt a taper surface matching structure, the taper surface has a continuous transition curved surface; the connecting part of the seat ring (3) and the back rib plate (4) adopts a circular arc transition structure.

2. The water inlet ball valve ball structure according to claim 1, characterized in that: The curvature radius of the back rib plate (4) and the outer diameter of the seat ring (3) have a proportional relationship of 0.8-1.2 times, the transition circular arc radius is not less than 1 / 3 of the thickness of the seat ring; the thickness of the back rib plate (4) decreases along the radial direction, the maximum thickness area is located at the connecting part of the seat ring (3), and the thickness value is 0.6-0.8 times of the thickness of the seat ring.

3. The water inlet ball valve ball structure according to claim 2, wherein: The thickness gradient decreasing angle of the back rib plate (4) is 3-5 degrees, and the thickness decreases by 5-8 mm along the radial direction every 100 mm.

4. The water inlet ball valve ball structure according to claim 3, wherein: The taper angle of the taper surface matching structure is 70-80 degrees, and the axial projection length of the taper surface is not less than 1.2 times of the diameter of the shaft neck.

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