Valve positioner

Abstract

The utility model provides a valve positioner, and belongs to the technical field of explosion suppression of valve positioners. The valve positioner comprises a shell and a feedback shaft assembly, the feedback shaft assembly comprises a bearing mechanism, a first main shaft and a second main shaft, the first main shaft and the second main shaft can be kept static relatively, the first main shaft and the second main shaft are configured to be of independent forming structures respectively, the bearing mechanism is connected with the shell, and the second main shaft is connected to the bearing mechanism. The first main shaft is provided with a feedback part protruding out of the first main shaft in the radial direction, the feedback part is used for feeding back the position of the feedback shaft assembly, and the end, deviating from the first main shaft in the axial direction, of the second main shaft is connected with an actuator matched with the valve positioner so that the feedback part can feed back the position of the actuator. According to the valve positioner, the production cost of the valve positioner can be reduced, and the explosion-proof performance of the valve positioner can be improved.

Description

A valve positioner Technical Field

[0001] This utility model relates to the field of explosion-proof technology for valve positioners, and in particular to a valve positioner. Background Technology

[0002] Valve positioners are key components in valve control. Together with valves and actuators, they form a basic controllable unit in a production pipeline. Valve positioners control the actuator's stroke to regulate valve opening and adjust the flow rate of media within the pipeline. With advancements in valve positioner technology, intelligent valve positioners have become market leaders due to their lower maintenance costs and superior interactive performance. During the operation of the actuator paired with the valve positioner, the valve positioner's feedback shaft assembly connects to the actuator to provide feedback on the actuator's actual position.

[0003] Among related technologies, the feedback shaft assembly has a high cost and insufficient explosion-proof performance. Summary of the Invention

[0004] This invention provides a valve positioner, the purpose of which is to reduce the cost of the feedback shaft assembly and improve the explosion-proof performance of the valve positioner.

[0005] To achieve the above objectives, this utility model provides a valve positioner, comprising:

[0006] shell;

[0007] The feedback shaft assembly includes a bearing mechanism, a first main shaft, and a second main shaft. The first main shaft is capable of remaining relatively stationary with respect to the second main shaft. The first and second main shafts are each configured as independently formed structures. The bearing mechanism is connected to the housing, and the second main shaft is connected to the bearing mechanism. The first main shaft has a feedback portion that protrudes radially from the first main shaft. The feedback portion is used to provide feedback on the position of the feedback shaft assembly. One end of the second main shaft, axially opposite to the first main shaft, is connected to an actuator that matches the valve positioner, so that the feedback portion can provide feedback on the position of the actuator.

[0008] In one embodiment, the feedback shaft assembly further includes a rotating sleeve disposed within the housing, and the first main shaft is connected to the rotating sleeve, the first main shaft being rotatable relative to the rotating sleeve.

[0009] In one embodiment, the feedback shaft assembly further includes a bushing through which the first spindle passes, the bushing being configured to restrict axial movement of the first spindle.

[0010] In one embodiment, the valve positioner further includes an eddy current circuit board, which is disposed opposite to the feedback unit along the radial direction of the first main shaft. When the first main shaft rotates, the feedback unit enables the eddy current circuit board to generate an induced current.

[0011] In one embodiment, the surface where the feedback unit intersects with the first spindle is called the feedback surface. The feedback surface is inclined to the radial direction of the first spindle. When the first spindle rotates, the feedback surface can induce a current in the eddy current circuit board.

[0012] In one embodiment, the first spindle is radially connected to the second spindle pin.

[0013] In one embodiment, the first spindle has a groove on the side axially close to the second spindle, and the side of the second spindle axially close to the first spindle is located within the groove.

[0014] In one embodiment, the bearing mechanism has an explosion-proof external thread, and the housing has an explosion-proof internal thread, so that the bearing mechanism and the housing are connected by the explosion-proof thread.

[0015] In one embodiment, the feedback axis assembly includes a pointer disposed on the side of the second spindle axially opposite to the first spindle, the pointer being configured to indicate the position of the second spindle.

[0016] In one embodiment, the feedback axis assembly includes an indicator block disposed on the side of the first spindle axially opposite to the second spindle, the indicator block being configured to indicate the position of the first spindle.

[0017] The above-mentioned solution of this utility model has the following beneficial effects:

[0018] In this embodiment, the feedback shaft assembly includes a first spindle and a second spindle, both of which are shorter than the length of a single main shaft. The shorter first and second spindles have lower machining difficulty and precision requirements, resulting in lower machining costs. Furthermore, during the assembly of the feedback shaft assembly with the housing, the first spindle primarily serves to provide feedback on the actual position of the actuator, eliminating the need for a corresponding bearing seat for stability. This eliminates the need for the feedback portion protruding radially from the first spindle to be inserted into the bearing mechanism, reducing the inner diameter of the bearing mechanism and thus saving space within the housing. The second spindle can be configured as a shaft member without protruding surfaces, allowing for a tighter fit between the second spindle and the bearing mechanism. This reduces cavities within the bearing mechanism, minimizing potential explosion sites within the valve positioner and improving its explosion-proof performance. Additionally, splitting a single main shaft into a first and second spindle reduces the difficulty of installing the feedback shaft assembly into the housing.

[0019] Other beneficial effects of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0020] Figure 1 is a schematic diagram of the valve positioner in one embodiment of the present invention from a certain perspective.

[0021] Figure 2 is a top view of the valve positioner in one embodiment of the present invention. The upper cover of the valve positioner is not shown in the figure.

[0022] Figure 3 is a schematic diagram of the cross-sectional structure at point AA in Figure 2;

[0023] Figure 4 is an enlarged schematic diagram of the structure at point B in Figure 3.

[0024] [Explanation of Labels in the Attached Images]

[0025] 1. Housing; 2. Feedback shaft assembly; 21. Bearing mechanism; 22. First spindle; 221. Feedback section; 2211. Feedback surface; 222. Groove; 23. Second spindle; 24. Rotating sleeve; 25. Bushing; 26. Pointer; 27. Indicator block; 3. Eddy current circuit board. Detailed Implementation

[0026] To make the technical problems, solutions, and advantages of this utility model clearer, a detailed description will be provided below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0027] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a locking connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0029] In related technologies, the feedback shaft assembly of a valve positioner is typically a continuous spindle. The spindle is relatively long, and its machining is difficult and requires high precision, resulting in high manufacturing costs. Furthermore, the spindle of the feedback shaft assembly usually has a radially protruding portion. This means that during the assembly of the entire spindle and the bearing mechanism, the inner diameter of the bearing mechanism needs to be much larger than the outer diameter of the spindle to accommodate the protruding portion. This wastes considerable space within the valve positioner's housing. The large gap between the bearing mechanism and the entire spindle provides a potential site for explosions within the valve positioner, which is detrimental to its explosion-proof capabilities.

[0030] In view of this, please refer to Figures 1 and 2. An embodiment of this utility model provides a valve positioner. Figures 1 and 2 respectively show the structure of the valve positioner of this application from different perspectives. The valve positioner of this application can be a common valve positioner, an explosion-proof valve positioner, or an intelligent explosion-proof valve positioner. Explosion-proof valve positioners are typically installed on production pipelines carrying flammable and explosive gases. By driving an actuator matched with the valve positioner, the opening of the valve stem is controlled, thereby regulating the flow rate of flammable and explosive gases in the production pipeline. Intelligent explosion-proof valve positioners may generate flames or sparks. Therefore, the intelligent explosion-proof valve positioner itself needs to have a good ability to prevent the internal flame from spreading to the outside flammable and explosive gases, in order to reduce the possibility of the internal flame igniting the flammable and explosive gases and improve the safety of production pipelines carrying flammable and explosive gases.

[0031] Figure 3 is a cross-sectional view of section AA in Figure 2, showing the relative positional relationship between the feedback shaft assembly 2 and the housing 1 in one embodiment. Specifically, the valve positioner includes the housing 1 and the feedback shaft assembly 2. The housing 1 can be made of a material with certain strength and rigidity, such as metal. The feedback shaft assembly 2 includes a bearing mechanism 21, a first main shaft 22, and a second main shaft 23. The bearing mechanism 21, the first main shaft 22, and the second main shaft 23 can all be made of materials with certain strength and rigidity, such as metal. The first main shaft 22 can remain relatively stationary with respect to the second main shaft 23. The first main shaft 22 and the second main shaft 23 are configured as independently formed structures, meaning that the first main shaft 22 and the second main shaft 23 can be independent shaft components. The bearing mechanism 21 is connected to the housing 1. For example, the bearing mechanism 21 can be disposed inside the housing 1. The housing 1 can include a base and a top cover, and the bearing mechanism 21 is connected to the base of the housing 1. The second spindle 23 is connected to the bearing mechanism 21. For example, the second spindle 23 can be inserted into the bearing mechanism 21. The bearing mechanism 21 can support the rotation of the second spindle 23, reduce the coefficient of friction of the second spindle 23 during rotation, and ensure the rotational accuracy of the second spindle 23 to a certain extent. The first spindle 22 has a feedback part 221 that protrudes radially from the first spindle 22. The feedback part 221 is used to provide feedback on the position of the feedback shaft assembly 2 of this application, so that the feedback shaft assembly 2 can provide feedback on the actual opening degree of the valve. The end of the second spindle 23 that is axially opposite to the first spindle 22 is connected to the actuator that matches the valve positioner, so that the feedback part 221 can provide feedback on the position of the actuator, and thus provide feedback on the actual opening degree of the valve.

[0032] For example, during the process of the valve positioner driving the actuator to move, the second spindle 23 connected to the actuator can also move synchronously, thereby driving the feedback part 221 of the first spindle 22 to move, so that the movement amplitude of the feedback part 221 can reflect the actual movement amplitude of the actuator, and thus reflect the actual opening degree of the valve.

[0033] In this embodiment, the feedback shaft assembly 2 includes a first spindle 22 and a second spindle 23, such that the lengths of both the first spindle 22 and the second spindle 23 are less than the length of a single spindle. The shorter first spindle 22 and the second spindle 23 have lower processing difficulty and accuracy requirements, resulting in lower processing costs. Furthermore, during the assembly of the feedback shaft assembly 2 with the housing 1, the first spindle 22 is mainly used to provide feedback on the actual position of the actuator, eliminating the need for a corresponding bearing seat for stabilization. This eliminates the need for the feedback portion 221, which protrudes radially from the first spindle 22, to be inserted into the bearing mechanism 21. This reduces the inner diameter of the bearing mechanism 21, thereby saving space within the housing 1. The second spindle 23 can be configured as a shaft member without protruding surfaces, allowing it to fit more tightly into the bearing mechanism 21. This reduces the cavity within the bearing mechanism 21, minimizing potential explosion sites within the valve positioner and improving its explosion-proof performance. Furthermore, splitting a single spindle into a first spindle 22 and a second spindle 23 reduces the difficulty of installing the feedback shaft assembly 2 into the housing 1.

[0034] In one embodiment, referring to Figures 3 and 4, the feedback shaft assembly 2 further includes a rotating sleeve 24. The rotating sleeve 24 can be made of a material with certain strength and rigidity, such as metal. The rotating sleeve 24 is disposed inside the outer casing 1, and the rotating sleeve 24 remains relatively stationary with respect to the outer casing 1. The first main shaft 22 is connected to the rotating sleeve 24. For example, the first main shaft 22 can be inserted into the rotating sleeve 24. The first main shaft 22 can rotate relative to the rotating sleeve 24. The feedback part 221 of the first main shaft 22 can be completely located inside the rotating sleeve 24. The sidewall of the feedback part 221 of the first main shaft 22 can be fitted against the inner wall of the rotating sleeve 24 as shown in Figure 3, so as to limit the rotation of the first main shaft 22 inside the rotating sleeve 24, which is beneficial to improving the stability of the first main shaft 22 during rotation. The side of the rotating sleeve 24 closest to the actuator can be connected to the bearing mechanism 21. During the installation of the feedback shaft assembly 2 onto the housing 1, the first main shaft 22 can be installed on the rotating sleeve 24 first, and then the whole assembly can be connected to the second main shaft 23 and the bearing mechanism 21 respectively. This ensures that the installation of the first main shaft 22 on the rotating sleeve 24 and the installation of the second main shaft 23 on the bearing mechanism 21 do not affect each other, making the installation relatively simple and convenient.

[0035] It is understood that the feedback shaft assembly 2 is not limited to including the rotating sleeve 24.

[0036] In one embodiment, referring to FIG4, the feedback shaft assembly 2 further includes a bushing 25. The bushing 25 can be made of a material with a certain degree of elasticity, such as rubber. The first spindle 22 passes through the bushing 25, and the bushing 25 is configured to restrict the axial movement of the first spindle 22 to reduce the axial vibration of the first spindle 22. Exemplarily, referring to FIG4, the bushing 25 can contact the rotating sleeve 24 and the first spindle 22 on both sides along the axial direction of the first spindle 22, respectively, so that the bushing 25 can compensate for the assembly gap between the first spindle 22 and the rotating sleeve 24. The bushing 25 has a certain degree of elasticity, which is beneficial to reducing the axial vibration of the first spindle 22.

[0037] It is understood that the feedback shaft assembly 2 is not limited to including bushing 25.

[0038] In one embodiment, referring to Figures 3 and 4, the valve positioner further includes an eddy current circuit board 3. The eddy current circuit board 3 is arranged radially opposite to the feedback unit 221 along the first main shaft 22. For example, as shown in Figure 3, the eddy current circuit board 3 can be located on the side of the rotating sleeve 24 that is radially away from the first main shaft 22. The eddy current circuit board 3 can be connected to the outer shell 1 or to the rotating sleeve 24. When the first main shaft 22 rotates, the feedback unit 221 can cause the eddy current circuit board 3 to generate an induced current. That is, when the first main shaft 22 rotates, the feedback unit 221 also rotates, causing the relative position between the feedback unit 221 and the eddy current circuit board 3 to change, so that different induced current signals are generated on the eddy current circuit board 3. The different induced current signals on the eddy current circuit board 3 correspond one-to-one with the different positions of the feedback unit 221. Therefore, the relative position of the feedback shaft assembly 2 can be determined based on the induced current signals, and thus the actual opening degree of the valve can be determined.

[0039] In this embodiment, the rotation angle of the feedback unit 221 can be converted into a corresponding induced current by the eddy current circuit board 3, and the actual opening degree of the valve can be further fed back, so that the internal structure of the valve positioner is relatively simple, based on the feedback shaft assembly 2 being able to feed back the actual opening degree of the valve.

[0040] In one embodiment, referring to Figures 3 and 4, the surface where the feedback unit 221 intersects with the first main shaft 22 is the feedback surface 2211. As shown in Figure 4, the feedback surface 2211 is inclined to the radial direction of the first main shaft 22, that is, the feedback surface 2211 is not perpendicular to the first main shaft 22. The angle between the feedback surface 2211 and the axial direction of the first main shaft 22 is an acute angle (or an obtuse angle). When the first main shaft 22 rotates, the feedback surface 2211 can induce current in the eddy current circuit board 3. That is, when the first main shaft 22 rotates, the feedback surface 2211 also rotates, causing the relative position between the feedback surface 2211 and the eddy current circuit board 3 to change, so that different induced current signals are generated on the eddy current circuit board 3. The different induced current signals on the eddy current circuit board 3 correspond one-to-one with the different positions of the feedback surface 2211. Therefore, the relative position of the feedback shaft assembly 2 can be determined based on the induced current signal, and thus the actual opening degree of the valve can be determined.

[0041] For example, referring to Figure 4, the number of feedback surfaces 2211 can be two, with the two feedback surfaces 2211 located on opposite sides of the feedback section 221 along the axial direction of the first main shaft 22. The number of feedback surfaces 2211 can also be one, with one feedback surface 2211 located on one side of the feedback section 221 along the axial direction of the first main shaft 22.

[0042] In this embodiment, the surface where the feedback part 221 intersects with the first main shaft 22 is the feedback surface 2211. That is, the feedback surface 2211 is located on one side of the feedback part 221 along the axial direction of the first main shaft 22. The feedback surface 2211 is inclined to the radial direction of the first main shaft 22, so that the relative position change between the feedback part 221 and the eddy current circuit board 3 can be reflected only in the relative position change between the feedback surface 2211 and the eddy current circuit board 3. This allows the distance between the side of the feedback part 221 and the eddy current circuit board 3 to remain unchanged, so that the side of the feedback part 221 can fit better with the inner wall of the rotating sleeve 24, which is beneficial to improving the rotational stability of the first main shaft 22.

[0043] In one embodiment, the first spindle 22 is connected to the second spindle 23 radially by a pin, making the connection between the first spindle 22 and the second spindle 23 axially more convenient and achieving higher positioning accuracy. For example, both the end of the first spindle 22 near the second spindle 23 and the end of the second spindle 23 near the first spindle 22 have pin holes along their own radial direction. Pins are inserted into the pin holes of the first spindle 22 and the second spindle 23 respectively, thereby connecting the first spindle 22 and the second spindle 23 by a pin.

[0044] It is understood that the first spindle 22 is not limited to a pin connection with the second spindle 23 along the axial direction. For example, the first spindle 22 may also be bolted to the second spindle 23 along the axial direction.

[0045] In one embodiment, referring to Figures 3 and 4, the first spindle 22 has a groove 222 on the side axially close to the second spindle 23, and the side of the second spindle 23 axially close to the first spindle 22 is located in the groove 222. On the one hand, this can reduce the sum of the axial lengths of the first spindle 22 and the second spindle 23, which is beneficial to reducing the size of the valve positioning. On the other hand, the fact that the side of the second spindle 23 axially close to the first spindle 22 is located in the groove 222 makes the connection between the first spindle 22 and the second spindle 23 more stable, thereby reducing the possibility of connection failure between the first spindle 22 and the second spindle 23.

[0046] It is understood that the end of the first spindle 22 axially close to the second spindle 23 is not limited to having a groove 222. Exemplarily, the end of the first spindle 22 axially close to the second spindle 23 can be directly connected to the second spindle 23.

[0047] In one embodiment, referring to Figure 3, the bearing mechanism 21 has an explosion-proof external thread, and the housing 1 has an explosion-proof internal thread, so that the bearing mechanism 21 and the housing 1 are connected by the explosion-proof thread. For example, it can be a standard explosion-proof thread connection. The specifications of the explosion-proof thread can be: a nominal diameter of 27 mm, a pitch of 2 mm, and 10 turns. The explosion-proof thread connection between the bearing mechanism 21 and the housing 1 reduces the possibility of flame inside the valve positioner propagating to the outside through the assembly gap between the bearing mechanism 21 and the housing 1, which helps to improve the explosion-proof performance of the valve positioner.

[0048] For example, the bearing mechanism 21 may include a bearing housing and a bearing, the bearing being disposed within the bearing housing, the second spindle 23 being inserted into the bearing, and the bearing housing having an explosion-proof external thread so that the bearing mechanism 21 is connected to the housing 1 via the explosion-proof thread.

[0049] In one embodiment, referring to Figures 1 and 3, the feedback shaft assembly 2 includes a pointer 26, which can be configured as a component with an indicative arrow. The pointer 26 is located on the side of the second main shaft 23 that is axially opposite to the first main shaft 22. The pointer 26 is configured to indicate the position of the second main shaft 23, so that the valve positioner commissioning personnel can more intuitively observe the rotation angle of the second main shaft 23, which is beneficial to improving the convenience of commissioning personnel in commissioning the valve positioner.

[0050] It is understood that the feedback axis component 2 is not limited to including pointer 26.

[0051] In one embodiment, referring to Figures 2 and 3, the feedback shaft assembly 2 includes an indicator block 27. The indicator block 27 is disposed on the side of the first main shaft 22 that is axially opposite to the second main shaft 23, and is configured to indicate the position of the first main shaft 22. It should be noted that the first main shaft 22 is typically disposed axially on the side of the second main shaft 23 near the upper cover of the housing 1, and the user can usually directly observe the first main shaft 22 through the at least partially transparent upper cover. The indicator block 27 being disposed on the side of the first main shaft 22 that is axially opposite to the second main shaft 23 allows the user to more intuitively observe the rotation angle of the first main shaft 22, which improves the convenience of using the valve positioner of this application.

[0052] It is understood that the feedback axis assembly 2 is not limited to including the indicator block 27.

[0053] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A valve positioner, characterized in that, include: shell; The feedback shaft assembly includes a bearing mechanism, a first main shaft, and a second main shaft. The first main shaft is capable of remaining relatively stationary with respect to the second main shaft. The first and second main shafts are each configured as independently formed structures. The bearing mechanism is connected to the housing, and the second main shaft is connected to the bearing mechanism. The first main shaft has a feedback portion that protrudes radially from the first main shaft. The feedback portion is used to provide feedback on the position of the feedback shaft assembly. One end of the second main shaft, axially opposite to the first main shaft, is connected to an actuator that matches the valve positioner, so that the feedback portion can provide feedback on the position of the actuator.

2. The valve positioner according to claim 1, characterized in that, The feedback shaft assembly also includes a rotating sleeve disposed inside the housing, and the first main shaft is connected to the rotating sleeve, and the first main shaft is rotatable relative to the rotating sleeve.

3. The valve positioner according to claim 2, characterized in that, The feedback shaft assembly also includes a bushing through which the first spindle passes, the bushing being configured to restrict axial movement of the first spindle.

4. The valve positioner according to claim 1, characterized in that, The valve positioner also includes an eddy current circuit board, which is arranged radially relative to the feedback unit along the first main shaft. When the first main shaft rotates, the feedback unit enables the eddy current circuit board to generate an induced current.

5. The valve positioner according to claim 4, characterized in that, The surface where the feedback unit intersects with the first spindle is called the feedback surface. The feedback surface is inclined to the radial direction of the first spindle. When the first spindle rotates, the feedback surface can induce a current in the eddy current circuit board.

6. The valve positioner according to claim 1, characterized in that, The first spindle is radially connected to the second spindle pin.

7. The valve positioner according to claim 1, characterized in that, The first spindle has a groove on the side axially close to the second spindle, and the side axially close to the first spindle is located within the groove.

8. The valve positioner according to claim 1, characterized in that, The bearing mechanism has an explosion-proof external thread, and the housing has an explosion-proof internal thread, so that the bearing mechanism and the housing are connected by the explosion-proof thread.

9. The valve positioner according to claim 1, characterized in that, The feedback axis assembly includes a pointer disposed on the side of the second spindle axially opposite to the first spindle, the pointer being configured to indicate the position of the second spindle.

10. The valve positioner according to claim 1, characterized in that, The feedback axis assembly includes an indicator block disposed on the side of the first spindle axially opposite to the second spindle, and the indicator block is configured to indicate the position of the first spindle.

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