A valve stem connection structure for a valve plug of a propeller regulating valve

Abstract

The application relates to the technical field of regulating valves, and provides a valve core valve rod connecting structure for a shaft flow type regulating valve, which comprises a valve rod, a valve core, a first nut and a second nut; the valve core is provided with a mounting through hole, one end of the valve rod penetrates through the mounting through hole, so that the valve core is sleeved on the valve rod; one end of the valve rod penetrating through the mounting through hole is provided with an external thread, the first nut is screwed on the external thread section of one end of the valve rod, so that the valve core is fixed on the valve rod; the external thread section of one end of the valve rod is also screwed with the second nut, and the second nut is located on the side, away from the valve core, of the first nut and abuts against the first nut. The valve core is fixed on the valve rod by using two nuts, the risk of loosening of the valve core is greatly reduced, and the working reliability of the regulating valve is improved.

Description

Technical Field

[0001] This application relates to the field of control valve technology, and in particular to a valve core and valve stem connection structure for an axial flow control valve. Background Technology

[0002] A regulating valve, also known as a control valve, is a final control element in the field of industrial automation process control. It receives control signals from the regulating control unit and uses power to change process parameters such as flow rate, pressure, temperature, and liquid level of the medium.

[0003] In actual use, existing control valves, due to harsh operating conditions such as high pressure differentials and multiphase media, share a common characteristic: the large pressure difference across the valve core and the complex composition of the medium result in significant impact at the valve core-stem connection. Furthermore, the impact force varies across different parts of the connection, causing uneven and unstable stress on the valve core and stem. This leads to severe vibration of the valve core, resulting in localized severe erosion and loosening or even detachment of the valve core-stem connection due to intense vibration. Additionally, for axial flow control valves used in gas transmission and distribution systems, the flow velocity at the valve core is very high. The medium at the valve core can erode the nut securing the valve core and the exposed valve stem, causing damage over time. This can lead to loosening of the nut and pose a safety hazard. Utility Model Content

[0004] To address the aforementioned problems, this application provides a valve core and stem connection structure for an axial flow control valve. The structure is ingeniously designed and simple in construction. This application utilizes two nuts to fix the valve core to the valve stem, significantly reducing the risk of valve core loosening and improving the operational reliability of the control valve. The technical solution adopted in this application is as follows:

[0005] A valve core and valve stem connection structure for an axial flow regulating valve includes: a valve stem, a valve core, a first nut, and a second nut; the valve core has a mounting through hole, and one end of the valve stem passes through the mounting through hole so that the valve core is sleeved on the valve stem; one end of the valve stem passing through the mounting through hole has an external thread, and the first nut is screwed onto the external thread section of one end of the valve stem so that the valve core is fixed to the valve stem; the second nut is also screwed onto the external thread section of one end of the valve stem, and the second nut is located on the side of the first nut away from the valve core and abuts against the first nut.

[0006] By using two nuts to secure the valve core to the valve stem, the risk of valve core loosening is greatly reduced, improving the operational reliability of the control valve. The second nut also protects the first nut, reducing gas erosion and lowering the risk of damage or loosening of the first nut.

[0007] In some embodiments, a washer is installed on the external threaded section at one end of the valve stem, and the washer is sandwiched between the valve core and the first nut. By adding the washer, the stability of the connection between the valve core and the valve stem is further improved on the basis of double nuts.

[0008] In some embodiments, the washer is an anti-loosening washer. The anti-loosening washer consists of two washers with radially textured outer surfaces and helical toothed inner surfaces. During installation, the large toothed surfaces (helical toothed surfaces) of the two washers are aligned, and the small toothed surfaces (radially textured surfaces) of the two washers respectively contact the first nut and the valve core. The anti-loosening washer achieves locking by generating lifting tension through the relative misalignment of the helical toothed surfaces. The working principle of the anti-loosening washer: After assembly, the helical toothed surfaces of the two washers are aligned, and the outer radially textured surfaces of the two washers are engaged with the contact surfaces of the first nut and the valve core. When the connection between the valve core and the valve stem is subjected to vibration, causing the nut to loosen, only the relative misalignment between the inner helical toothed surfaces of the two washers in the anti-loosening washer is allowed, generating lifting tension, thereby achieving a 100% locking effect. Compared to traditional single-layer washers that rely on friction for anti-loosening, the anti-loosening washer has more reliable anti-loosening performance.

[0009] In some embodiments, the second nut is a cap nut. By using a cap nut, the end of the valve stem is located inside the cap nut, which protects the end of the valve stem from gas erosion, reducing the risk of damage to the valve stem end and its external threads. Furthermore, the cap nut protects the first nut, reducing gas erosion and lowering the risk of damage or loosening of the first nut.

[0010] In some embodiments, the second nut has a skirt portion that is annularly closed around the axis of the second nut, and the first nut is covered within the receiving space formed by the skirt portion.

[0011] By providing a skirt, the first nut is enclosed within the space formed by the skirt. The skirt provides excellent protection for the first nut, preventing gas from directly impacting it and thus avoiding loosening.

[0012] In some embodiments, the end of the second nut furthest from the first nut has a spherical structure.

[0013] By setting the end of the second nut away from the first nut to a spherical structure, the spherical structure guides the gas flow, which can reduce the scouring effect of the gas and reduce the risk of the first and second nuts loosening.

[0014] In some embodiments, the second nut undergoes a QPQ process. QPQ (Quench-Polish-Quench) is an abbreviation for a salt bath composite treatment technology that involves quenching, polishing, and quenching. After this treatment, a dense compound layer and oxide film are formed on the metal surface, resulting in high wear resistance, corrosion resistance, and fatigue resistance. The second nut, after QPQ treatment, has a very high surface hardness, effectively preventing damage caused by gas impacts.

[0015] The valve core and stem connection structure for an axial flow control valve provided in this application has at least one of the following beneficial effects:

[0016] 1. This application provides a valve core and stem connection structure for an axial flow control valve. By using two nuts to fix the valve core to the valve stem, the risk of valve core loosening is greatly reduced, thus improving the operational reliability of the control valve. The second nut protects the first nut, reducing gas erosion of the first nut and lowering the risk of damage or loosening.

[0017] 2. The valve core and valve stem connection structure for an axial flow control valve provided in this application further improves the stability of the connection between the valve core and valve stem by setting a washer, based on the double nut.

[0018] 3. This application provides a valve core and stem connection structure for an axial flow regulating valve. The selected washer is an anti-loosening washer, consisting of two washers with radially textured outer surfaces and helical toothed inner surfaces. During installation, the large toothed surfaces (helical toothed surfaces) of the two washers should face each other, and the small toothed surfaces (radially textured surfaces) of the two washers should contact the first nut and the valve core respectively. The anti-loosening washer achieves locking by generating lifting tension through the relative misalignment of the helical toothed surfaces. The working principle of the anti-loosening washer: After assembly, the helical toothed surfaces of the two washers face each other, and the outer radially textured surfaces of the two washers are engaged with the contact surfaces of the first nut and the valve core respectively. When the connection between the valve core and the valve stem is subjected to vibration, causing the nut to loosen, only the relative misalignment between the inner helical toothed surfaces of the two washers in the anti-loosening washer is allowed, generating lifting tension, thereby achieving a 100% locking effect. Compared to traditional single-layer washers that rely on friction to prevent loosening, anti-loosening washers offer more reliable anti-loosening performance.

[0019] 4. This application provides a valve core and stem connection structure for an axial flow control valve. By employing a cap nut, the end of the valve stem is located inside the cap nut. The cap nut protects the end of the valve stem, preventing gas from eroding it and reducing the risk of damage to the valve stem end and its external threads. Furthermore, the cap nut protects the first nut, reducing gas erosion and lowering the risk of damage or loosening of the first nut.

[0020] 5. The valve core and valve stem connection structure for an axial flow regulating valve provided in this application, by setting a skirt, the first nut is covered in the receiving space formed by the skirt. The skirt plays a good protective role for the first nut, preventing gas from directly eroding the first nut and avoiding the first nut from loosening.

[0021] 6. The valve core and valve stem connection structure for an axial flow regulating valve provided in this application is configured as a spherical structure at the end of the second nut away from the first nut. The spherical structure guides the gas flow, which can reduce the scouring effect of the gas and reduce the risk of the first nut and the second nut becoming loose.

[0022] 7. This application provides a valve core and stem connection structure for an axial flow control valve. QPQ (Quench-Polish-Quench) is an abbreviation for "quenching-polishing-quenching" salt bath composite treatment technology. After the workpiece is treated with this technology, a dense compound layer and oxide film are formed on the metal surface, which has high wear resistance, corrosion resistance, and fatigue resistance. After the second nut is treated with the QPQ process, the surface hardness is very high, which can effectively prevent damage caused by gas impact. Attached Figure Description

[0023] The preferred embodiments will be described below in a clear and easy-to-understand manner, with reference to the accompanying drawings, to further explain the above-mentioned characteristics, technical features, advantages, and implementation methods of a valve core and valve stem connection structure for an axial flow control valve:

[0024] Figure 1 This is a schematic diagram of the overall structure of the valve core and valve stem connection structure of this application.

[0025] Explanation of icon numbers:

[0026] Valve stem 1, tapered section 11, valve core 2, first nut 3, second nut 4, skirt 41, receiving space 411, spherical structure 42, washer 5. Detailed Implementation

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the specific implementation methods of this application will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without creative effort.

[0028] To keep the drawings concise, each drawing only schematically shows the parts relevant to this application, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of the components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0029] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0030] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0031] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0032] refer to Figure 1 This application provides a valve core and valve stem connection structure for an axial flow regulating valve, comprising: a valve stem 1, a valve core 2, a first nut 3, and a second nut 4; the valve core 2 is provided with a mounting through hole, and one end of the valve stem 1 passes through the mounting through hole so that the valve core 2 is sleeved on the valve stem 1; the end of the valve stem 1 passing through the mounting through hole is provided with an external thread, and the first nut 3 is screwed onto the external thread section at one end of the valve stem 1 so that the valve core 2 is fixed on the valve stem 1; a second nut 4 is also screwed onto the external thread section at one end of the valve stem 1, and the second nut 4 is located on the side of the first nut 3 away from the valve core 2 and abuts against the first nut 3.

[0033] Specifically, in one embodiment, the valve stem 1 can be as follows: Figure 1 As shown, the valve stem 1 includes a tapered section 11. The mounting through-hole on the valve core 2 is a tapered hole adapted to the tapered section 11, through which the valve core 2 fits onto the tapered section 11 of the valve stem 1. The first nut 3 and the second nut 4 are screwed onto the end of the valve stem 1 to limit the axial displacement of the valve core 2 and prevent it from detaching from the end of the valve stem 1. The valve stem 1 body and the valve stem 1 end are connected via the tapered section 11. This reduces or avoids stress concentration at the connection between the valve stem 1 body and the valve stem 1 end, lowering the risk of damage at this connection and improving the overall reliability of the valve stem 1.

[0034] In another specific embodiment, unlike the previous embodiment which used a tapered section 11, the tapered section 11 of the valve stem 1 is replaced by a stepped shaft. The valve stem 1 body is a large-diameter section, while the valve stem 1 end is a small-diameter section. The mounting through hole of the valve core 2 is adapted to the small-diameter section, and the valve core 2 is fitted onto the small-diameter section, with the valve core 2 abutting against the shoulder of the stepped shaft. The first nut 3 and the second nut 4 are screwed onto the small-diameter section to limit the axial displacement of the valve core 2 and prevent the valve core 2 from falling off the end of the valve stem 1.

[0035] Understandably, by using two nuts to fix the valve core 2 to the valve stem 1, the risk of the valve core 2 loosening is greatly reduced, thus improving the operational reliability of the regulating valve. The second nut 4 protects the first nut 3, reducing the erosion of the first nut 3 by gas and lowering the risk of damage or loosening of the first nut 3.

[0036] refer to Figure 1 In one embodiment, a washer 5 is installed on the external threaded section at one end of the valve stem 1, and the washer 5 is sandwiched between the valve core 2 and the first nut 3. By setting the washer 5, the stability of the connection between the valve core 2 and the valve stem 1 is further improved on the basis of double nuts.

[0037] Specifically, washer 5 can be a traditional single-layer washer that relies on friction to prevent loosening, or it can be an anti-loosening washer with superior anti-loosening performance. Preferred anti-loosening washers consist of two washers with radially textured outer surfaces and helical toothed inner surfaces. During installation, the large toothed surfaces (helical toothed surfaces) of the two washers should face each other, and the small toothed surfaces (radially textured surfaces) of the two washers should contact the first nut 3 and the valve core 2 respectively. This anti-loosening washer achieves locking by generating lifting tension through the relative misalignment of the helical toothed surfaces. The working principle of the anti-loosening washer: After assembly, the helical toothed surfaces of the two washers face each other, and the outer radially textured surfaces of the two washers are engaged with the contact surfaces of the first nut 3 and the valve core 2 respectively. When the connection between the valve core 2 and the valve stem 1 is subjected to vibration, causing the nut to loosen, only the relative misalignment between the inner helical toothed surfaces of the two washers in the anti-loosening washer is allowed, generating lifting tension, thereby achieving a 100% locking effect. Compared to traditional single-layer washers that rely on friction to prevent loosening, anti-loosening washers offer more reliable anti-loosening performance. Since anti-loosening washers are existing technology, their specific structure will not be elaborated upon here.

[0038] refer to Figure 1In one embodiment, the second nut 4 is a cap nut. By using a cap nut, the end of the valve stem 1 is located inside the cap nut, which protects the end of the valve stem 1, preventing gas from eroding the end of the valve stem 1 and reducing the risk of damage to the end of the valve stem 1 and its external threads. Furthermore, the cap nut protects the first nut 3, reducing gas erosion of the first nut 3 and lowering the risk of damage and loosening of the first nut 3.

[0039] Further, refer to Figure 1 In one embodiment, the cap nut (second nut 4) has a skirt portion 41, which is arranged in a closed loop around the axis of the cap nut. The first nut 3 is covered within the receiving space 411 formed by the skirt portion 41. By providing the skirt portion 41, the first nut 3 is covered within the receiving space 411, which provides good protection for the first nut 3, preventing gas from directly impacting it and avoiding loosening.

[0040] refer to Figure 1 In one embodiment, the end of the cap nut (second nut 4) away from the first nut 3 is a spherical structure 42. By setting the end of the second nut 4 away from the first nut 3 as a spherical structure 42, the spherical structure 42 guides the gas flow, reduces the scouring effect of the gas, and lowers the risk of the first nut 3 and the second nut 4 becoming loose.

[0041] In one embodiment, the cap nut (second nut 4) undergoes QPQ processing. QPQ (Quench-Polish-Quench) is an abbreviation for "quench-polish-quench" salt bath composite treatment technology. After the workpiece undergoes this technology, a dense compound layer and oxide film are formed on the metal surface, which combines high wear resistance, corrosion resistance, and fatigue resistance. After the second nut 4 undergoes QPQ processing, the surface hardness is very high, with a Vickers hardness of up to 1000, which can effectively prevent damage caused by gas impact.

[0042] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of this application. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A valve core and stem connection structure for an axial flow control valve, characterized in that, include: The valve stem, valve core, first nut, and second nut are provided. The valve core has a mounting through hole, and one end of the valve stem passes through the mounting through hole so that the valve core is sleeved on the valve stem. The end of the valve stem passing through the mounting through hole has an external thread, and the first nut is screwed onto the external thread section of the valve stem to fix the valve core to the valve stem. The second nut is also screwed onto the external thread section of the valve stem, and the second nut is located on the side of the first nut away from the valve core and abuts against the first nut.

2. The valve core and stem connection structure for an axial flow regulating valve according to claim 1, characterized in that, A washer is installed on the external thread section at one end of the valve stem, and the washer is sandwiched between the valve core and the first nut.

3. The valve core and stem connection structure for an axial flow regulating valve according to claim 2, characterized in that, The washer is an anti-loosening washer.

4. A valve core and stem connection structure for an axial flow regulating valve according to any one of claims 1-3, characterized in that, The second nut is a cap nut.

5. The valve core and stem connection structure for an axial flow regulating valve according to claim 4, characterized in that, The second nut has a skirt portion, which is arranged in a closed loop around the axis of the second nut, and the first nut is covered in the receiving space formed by the skirt portion.

6. The valve core and stem connection structure for an axial flow regulating valve according to claim 5, characterized in that, The end of the second nut furthest from the first nut has a spherical structure.

7. A valve core and stem connection structure for an axial flow regulating valve according to claim 5 or 6, characterized in that, The second nut is processed using the QPQ process.

8. The valve core and stem connection structure for an axial flow regulating valve according to claim 4, characterized in that, The side of the second nut furthest from the first nut has a spherical structure.

9. The valve core and stem connection structure for an axial flow regulating valve according to claim 8, characterized in that, The second nut is processed using the QPQ process.

10. The valve core and stem connection structure for an axial flow regulating valve according to claim 4, characterized in that, The second nut is processed using the QPQ process.

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