Easy-to-open eccentric butterfly valve

Abstract

This invention provides an easy-to-open eccentric butterfly valve, comprising an actuator; a valve stem with a connecting sleeve between the valve stem and the actuator for connecting the output end of the actuator to the valve stem; and a rectangular external spline passing through the valve stem, the external spline including a first spline tooth tip, a first spline sidewall, and a second spline sidewall, at least one of the first and second spline sidewalls being inclined. This invention achieves surface contact transmission by setting the inclined spline sidewall, significantly improving torque transmission efficiency, reducing stress concentration and wear, and simultaneously reducing the torque required for valve opening and closing, thus improving valve accuracy. Therefore, it can reduce the configuration requirements of the actuator and lower the valve's production cost.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, and in particular to an eccentric butterfly valve that is easy to open. Background Technology

[0002] Eccentric butterfly valves have advantages such as advanced structure, reliable sealing, long service life, and low cost. They are widely used to control fluids with large flow rates, medium to low pressure differentials, and strict leakage control requirements. They are economical and practical automatic control valves that combine both regulation and shut-off functions.

[0003] With the continuous development of industry, the requirements for eccentric butterfly valves are also constantly increasing. While meeting conventional functions, triple eccentric butterfly valves are now required to have higher sealing performance, accurate adjustment precision, and low torque, in order to further reduce the cost of butterfly valves and minimize installation space. In existing technology, eccentric butterfly valves mainly achieve valve opening and closing by having an actuator drive the valve stem to rotate, which in turn drives the valve plate to rotate. The output end of the actuator and the valve stem are usually connected by a rectangular spline to transmit torque. When an eccentric butterfly valve opens under the force of the medium, it needs to overcome the force of the medium to open the valve. Therefore, eccentric butterfly valves are usually equipped with actuators with high output power, increasing the production cost for enterprises. Utility Model Content

[0004] This utility model provides an eccentric butterfly valve that is easy to open, in order to solve the technical problem of excessive cost of the actuator of the eccentric butterfly valve.

[0005] This utility model provides an easy-to-open eccentric butterfly valve, which includes: Executive agency; A valve stem is provided with a connecting sleeve between the valve stem and the actuator, the connecting sleeve being used to connect the output end of the actuator and the valve stem; A rectangular external spline is disposed on the valve stem and is used to connect with the connecting sleeve. The rectangular external spline includes a first spline tooth tip, a first spline sidewall, and a second spline sidewall, at least one of the first spline sidewall and the second spline sidewall being inclined.

[0006] In one embodiment of the present invention, the rectangular external spline includes an external spline tooth groove, and the inclination direction of the first spline sidewall and / or the second spline sidewall is inclined along the external spline tooth groove toward the tip of the first spline tooth.

[0007] In one embodiment of the present invention, the connecting sleeve has a first connecting part and a second connecting part, the second connecting part being used to connect to the output end of the actuator, and the first connecting part being connected to the valve stem via the rectangular external spline.

[0008] In one embodiment of the present invention, the first connecting portion is provided with a rectangular inner spline for cooperating with the rectangular outer spline, and the rectangular inner spline is used to transmit the torque of the connecting sleeve to the rectangular outer spline.

[0009] In one embodiment of the present invention, the rectangular inner spline includes a second spline tooth tip, a third spline sidewall, and a fourth spline sidewall. The third spline sidewall can be used to mate with the first spline sidewall, and the fourth spline sidewall can be used to mate with the second spline sidewall.

[0010] In one embodiment of this utility model, when the third spline sidewall cooperates with the first spline sidewall to transmit torque to open the valve, and the fourth spline sidewall cooperates with the second spline sidewall to transmit torque to close the valve, the first spline sidewall and the third spline sidewall are inclined, and the inclination angle of the third spline sidewall is the same as that of the first spline sidewall. The third spline sidewall drives the first spline sidewall to transmit torque through surface contact.

[0011] In one embodiment of the present invention, the inclination angle of the first spline sidewall and / or the second spline sidewall is 15°-25°.

[0012] In one embodiment of the present invention, the first connecting part is provided with a plurality of locking screws in the circumferential direction, and the locking screws penetrate into the first connecting part radially and abut against the external spline groove.

[0013] In one embodiment of the present invention, the output end of the actuator is detachably connected to the second connecting part.

[0014] The beneficial effects of this utility model are as follows: The eccentric butterfly valve proposed in this utility model is easy to open. By setting the inclined spline sidewall, it achieves surface contact transmission, which significantly improves the torque transmission efficiency, reduces stress concentration and wear, and reduces the torque required for valve opening and closing. Therefore, it can reduce the configuration requirements of the actuator and reduce the production cost of the valve. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0016] In the attached diagram: Figure 1 A schematic diagram provided for one embodiment of this utility model; Figure 2This is an enlarged view of point A provided in one embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the fit between a rectangular external spline and a rectangular internal spline in one embodiment of the present invention. Figure 4 This is an enlarged view of point B provided in one embodiment of this utility model; Figure 5 This is a schematic diagram of a rectangular external spline provided in one embodiment of the present invention.

[0017] The attached figures are labeled as follows: Actuator 1, connecting sleeve 2, first connecting part 201, second connecting part 202, rectangular inner spline 203, third spline sidewall 2031, fourth spline sidewall 2032, second spline tooth tip 3033, valve stem 3, rectangular outer spline 301, first spline sidewall 3011, second spline sidewall 3012, first spline tooth tip 3013, outer spline tooth groove 3014, locking screw 4. Detailed Implementation

[0018] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0019] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0020] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present invention.

[0021] like Figures 1-5 As shown, this utility model provides an eccentric butterfly valve that is easy to open.

[0022] In an exemplary embodiment, the easily operable eccentric butterfly valve includes an actuator 1, a valve stem 3, and a connecting sleeve 2. The connecting sleeve 2 is disposed between the actuator 1 and the valve stem 3, and is used to connect the output end of the actuator 1 and the valve stem 3. A rectangular external spline 301 is disposed on the outer peripheral surface of the valve stem 3, and the rectangular external spline 301 is integrally formed with the valve stem. The rectangular external spline 301 includes a first spline tooth tip 3013, a first spline sidewall 3011, and a second spline sidewall 3012, wherein at least one of the first spline sidewall 3011 and the second spline sidewall 3012 is inclined.

[0023] In this embodiment, by optimizing the structural design of the rectangular external spline 301, a more efficient torque transmission path is established between the actuator 1 and the valve stem 3. Specifically, the inclined spline sidewall changes the traditional line contact force transmission mode of the rectangular spline, allowing the output torque of the actuator 1 to be transmitted more evenly to the valve stem 3 through the inclined contact surface during valve opening. This reduces the stress intensity per unit area and increases the stress area of ​​the internal and external splines when transmitting torque, effectively reducing the power required by the actuator 1 while ensuring the reliability of torque transmission. Therefore, when using the structure of this application to open and close the valve, the power requirement is reduced through structural optimization, thereby reducing the cost of the actuator 1.

[0024] For example, in this embodiment, due to the special structure of the eccentric butterfly valve, when the valve opens counterclockwise under the force of the medium, it is necessary to overcome the force of the medium to open the valve; when it closes clockwise, the force of the medium pushes the valve to close. Therefore, the opening torque of the butterfly valve in the flow-closing direction is usually greater than the closing torque. Therefore, in this application, the spline sidewall used to open the valve is set as an inclined surface, and the other spline sidewall is perpendicular to the radial direction of the valve stem 3. In another embodiment, both spline sidewalls are inclined, so that the cross-section of a single key of the rectangular outer spline 301 is trapezoidal, thereby increasing the contact area of ​​the inner and outer splines when opening and closing.

[0025] For example, the rectangular external spline 301 includes an external spline groove 3014, and the inclination direction of the first spline sidewall 3011 and / or the second spline sidewall 3012 is inclined along the external spline groove 3014 towards the first spline tooth tip 3013. Specifically, the angle range of the first spline sidewall 3011 and / or the second spline sidewall 3012 has been verified by finite element analysis to balance the effect of increasing the contact area and structural strength. In a specific embodiment, the inclined sidewall can be a straight inclined surface, and its processing technology is compatible with existing spline milling technology; in another embodiment, the spline sidewall can also be a micro-arc inclined surface, which can increase the contact area of ​​the inner and outer splines when transmitting torque.

[0026] In an exemplary embodiment, the connecting sleeve 2 has a first connecting part 201 and a second connecting part 202. The second connecting part 202 is used to connect to the output end of the actuator 1. The connection method is a detachable connection. Specifically, the first connecting part 201 is connected to the valve stem 3 through a rectangular external spline 301.

[0027] In this embodiment, the connection between the actuator 1 and the valve stem 3 is decomposed into two independent functional units by the connecting sleeve 2. The second connecting part 202 realizes the torque transmission at the output end of the actuator 1, so that the entire connecting sleeve 2 receives the torque transmitted by the actuator 1, ensuring the stability of the power transmission reference plane; the first connecting part 201 utilizes the mechanical interlocking characteristics of the rectangular spline to ensure the accuracy of torque transmission while also enabling the valve stem and the connecting sleeve to be freely disassembled axially.

[0028] For example, the output end of the actuator 1 is connected to the second connection part 202 via a flat key to transmit torque.

[0029] For example, the second connecting part 202 and the output end of the actuator 1 can also be connected by a flange, and bolts are provided to achieve axial locking.

[0030] For example, the second connection 202 and the output end of the actuator 1 can also be connected by a thread.

[0031] In an exemplary embodiment, the first connecting portion 201 is provided with a rectangular inner spline 203 for cooperating with the rectangular outer spline 301. The rectangular inner spline 203 is used to transmit the torque of the connecting sleeve 2 to the rectangular outer spline 301.

[0032] In this embodiment, a reliable torque transmission between the connecting sleeve 2 and the valve stem 3 is achieved by providing a rectangular inner spline 203 that mates with the rectangular outer spline 301 in the first connecting part 201. Specifically, when the actuator 1 generates torque, the torque is first transmitted to the connecting sleeve 2, and then transmitted to the valve stem 3 through the meshing action of the rectangular inner spline 203 and the rectangular outer spline 301. This makes the torque transmission path more direct and avoids the slippage that may occur when directly transmitting torque. In this embodiment, due to the use of a rectangular spline structure, the size of the connecting parts can be reduced when transmitting the same torque, thereby reducing material costs. At the same time, the self-centering characteristic of the spline connection simplifies the assembly process and improves production efficiency.

[0033] For example, the third spline sidewall 2031 is used to mate with the first spline sidewall 3011 of the rectangular outer spline 301 to transmit torque, and the fourth spline sidewall 2032 is used to mate with the second spline sidewall 3012 of the rectangular outer spline 301 to transmit torque. The second spline tooth tip 3033 corresponds to and matches the outer spline tooth groove 3014 of the rectangular outer spline 301. In a specific embodiment, the tooth profile parameters of the rectangular inner spline 203 can be completely matched with those of the rectangular outer spline 301 to ensure tight meshing. Specifically, the tooth groove width of the rectangular inner spline 203 can maintain a 0.05-0.15mm fit clearance with the tooth thickness of the rectangular outer spline 301, ensuring assembly efficiency while ensuring the contact area when transmitting torque. In another embodiment, the tooth height of the rectangular inner spline 203 can be slightly larger than the tooth height of the rectangular outer spline 301 to ensure effective meshing even after long-term wear.

[0034] It is worth noting that in this embodiment, the third spline sidewall 2031 and the fourth spline sidewall 2032 can adopt a symmetrical or asymmetrical inclined design, and the second spline tooth tip 3033 can be designed as a plane or a slightly convex arc surface to adapt to the geometry of the outer spline tooth groove 3014.

[0035] It should also be noted that in this embodiment, when the transmission torque opens the valve, the third spline sidewall 2031 engages with the first spline sidewall 3011; when the transmission torque closes the valve, the fourth spline sidewall 2032 engages with the second spline sidewall 3012. Therefore, in accordance with the torque transmission part when the valve is open, the first spline sidewall 3011 and the third spline sidewall 2031 are inclined, and the inclination angle of the third spline sidewall 2031 is the same as the inclination angle of the first spline sidewall 3011, so that when the third spline sidewall 2031 drives the first spline sidewall 3011, the two can be fully engaged, thereby achieving torque transmission through surface contact. The fourth spline sidewall 2032 and the second spline sidewall 3012 remain unchanged, or are also inclined, but since the force required when the valve is closed is small, the inclination angle of the second spline sidewall and the fourth spline sidewall can be smaller than the inclination angle of the first spline sidewall 3011.

[0036] In one exemplary embodiment, such as Figure 5 As shown, the inclination angle of the first spline sidewall 3011 and / or the second spline sidewall 3012 is α, and the range of α is 15°-25°.

[0037] In this embodiment, by limiting the inclination angle of the spline sidewall to the range of 15°-25°, the problems of torque transmission efficiency and valve operating performance are effectively solved. This ensures that the spline forms a sufficient contact area when transmitting torque while maintaining low frictional resistance. Therefore, in this embodiment, the valve operating torque is significantly reduced while ensuring reliable torque transmission, allowing the actuator 1 to be a lower-power model, thereby reducing production costs. Furthermore, the selection of the 15°-25° range also considers the feasibility of the processing technology, enabling mass production while maintaining accuracy.

[0038] For example, in this embodiment, the tilt angles of the first spline sidewall 3011 and the third spline sidewall 2031 are set to 18°, 20° or 22°.

[0039] In an exemplary embodiment, the first connecting portion 201 is provided with a plurality of locking screws 4 in the circumferential direction. The locking screws 4 penetrate the first connecting portion 201 radially and abut against the external spline groove 3014.

[0040] In this embodiment, the circumferentially distributed locking screws 4 generate radial mechanical locking force, which acts directly on the key parts of the spline drive's tooth grooves. When the actuator 1 transmits torque, the rigid contact between the screws and the tooth grooves effectively suppresses radial displacement and circumferential fretting of the spline pair, eliminating the gap accumulation that may occur in traditional spline connections under high-frequency alternating loads. Specifically, the static friction force generated by the screw preload and the pressure on the spline meshing surface form a dual anti-loosening mechanism, which can improve the anti-loosening ability between the connecting sleeve 2 and the spline. This reduces the transmission delay caused by the gap between the inner and outer splines, ensuring the positioning accuracy and transmission reliability of the valve opening and closing action.

[0041] For example, in this embodiment, the locking screw 4 can be a hex socket head cap screw or a countersunk screw, with 2-5 screws evenly distributed circumferentially. The screw insertion depth must ensure that its end makes effective contact with the tooth groove, and the contact surface can be machined into a flat surface or an arc surface to match the tooth groove profile.

[0042] In summary, this utility model achieves surface contact transmission by setting an inclined spline sidewall, which significantly improves torque transmission efficiency, reduces stress concentration and wear, and at the same time reduces the torque required for valve opening and closing, improving valve accuracy. Therefore, it can reduce the configuration requirements of actuator 1 and reduce valve production costs.

[0043] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. An eccentric butterfly valve that is easy to open, characterized in that, include: Executive agency; A valve stem is provided with a connecting sleeve between the valve stem and the actuator, the connecting sleeve being used to connect the output end of the actuator and the valve stem; A rectangular external spline is disposed on the valve stem and is used to connect with the connecting sleeve. The rectangular external spline includes a first spline tooth tip, a first spline sidewall, and a second spline sidewall, at least one of the first spline sidewall and the second spline sidewall being inclined.

2. The easy-to-open eccentric butterfly valve according to claim 1, characterized in that: The rectangular external spline includes an external spline tooth groove, and the inclination direction of the first spline sidewall and / or the second spline sidewall is inclined along the external spline tooth groove toward the tip of the first spline tooth.

3. The easy-to-open eccentric butterfly valve according to claim 2, characterized in that: The connecting sleeve has a first connecting part and a second connecting part. The second connecting part is used to connect to the output end of the actuator, and the first connecting part is connected to the valve stem through the rectangular external spline.

4. The easy-to-open eccentric butterfly valve according to claim 3, characterized in that: The first connecting part is provided with a rectangular inner spline for cooperating with the rectangular outer spline, and the rectangular inner spline is used to transmit the torque of the connecting sleeve to the rectangular outer spline.

5. The easy-to-open eccentric butterfly valve according to claim 1, characterized in that: The rectangular inner spline includes a second spline tooth tip, a third spline sidewall, and a fourth spline sidewall. The third spline sidewall can be used to mate with the first spline sidewall, and the fourth spline sidewall can be used to mate with the second spline sidewall.

6. The easy-to-open eccentric butterfly valve according to claim 5, characterized in that: When the third spline sidewall cooperates with the first spline sidewall to transmit torque to open the valve, and the fourth spline sidewall cooperates with the second spline sidewall to transmit torque to close the valve, the first spline sidewall and the third spline sidewall are inclined, and the inclination angle of the third spline sidewall is the same as that of the first spline sidewall. The third spline sidewall drives the first spline sidewall to transmit torque through surface contact.

7. The easy-to-open eccentric butterfly valve according to claim 1, characterized in that: The inclination angle of the first spline sidewall and / or the second spline sidewall is 15°-25°.

8. The easy-to-open eccentric butterfly valve according to claim 3, characterized in that: The first connecting part is provided with a plurality of locking screws in the circumferential direction. The locking screws penetrate the first connecting part radially and abut against the external spline groove.

9. The easy-to-open eccentric butterfly valve according to claim 1, characterized in that: The output end of the actuator is detachably connected to the second connecting part.

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