Valve position sensor connecting structure for valve positioner

Abstract

A valve position sensor connecting structure for a valve positioner comprises an installation supporting seat, a feedback shaft and a sliding resistance sensor which are fixed to a bottom shell of the valve positioner, the installation supporting seat is used for being fixed to the bottom shell of the valve positioner, and an insertion hole penetrating through the upper surface and the lower surface of the installation supporting seat is formed in the installation supporting seat; the feedback shaft is inserted into the insertion hole and can rotate relative to the installation supporting seat, the feedback shaft is in limiting fit with the installation supporting seat in the axial direction of the feedback shaft, the bottom of the feedback shaft is located on the outer side of the insertion hole and forms a transmission part used for being connected with an external feedback connecting piece, and a limiting groove extending in the axial direction of the feedback shaft is formed in the upper surface of the feedback shaft; a rotating shaft of the sliding resistance sensor is inserted into the limiting groove, the lower portion of the rotating shaft is fixedly connected and elastically matched with the inner wall of the limiting groove, and the rotating shaft of the sliding resistance sensor synchronously rotates along with the feedback shaft.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, and in particular to a valve position sensor connection structure for a valve positioner. Background Technology

[0002] A valve positioner is an automated device used to precisely control the opening of a valve. It is typically used in conjunction with pneumatic, electric, or electro-hydraulic valve actuators to adjust the valve position in real time, ensuring the valve opening matches the set value and enabling precise regulation of process parameters such as fluid flow, pressure, and temperature. The valve position sensor is one of the core components of the valve positioner. It detects the actual position of the valve in real time, converting the valve's mechanical displacement signal into an electrical or digital signal, which is then fed back to the control system to form a closed-loop control, ensuring precise matching between the valve opening and the set value. Valve position sensors in valve positioners mainly include two types: sliding resistance sensors and magnetoresistive Hall effect sensors. For sliding resistance sensors, during operation, the pneumatic actuator drives the feedback shaft to rotate via a feedback connector, which in turn drives the sliding resistance sensor to rotate. The valve positioner's control module collects the signal from the sliding resistance sensor to obtain the actual valve position, thereby achieving precise valve control.

[0003] Currently, valve position sensors on the market are mainly connected to the feedback shaft via direct connection, gear drive, or hollow shaft. When using a direct connection, the rotating shaft of the sliding resistance sensor is lengthened to serve as the feedback shaft for the valve positioner and connect to the feedback connector. When using a gear drive, a first gear is mounted on the rotating shaft of the sliding resistance sensor, and a second gear is mounted on the feedback shaft. The meshing of the first and second gears rotates the feedback shaft, driving the sensor to rotate. When using a hollow shaft, the internal shaft of the sliding resistance sensor is hollow, and a rotating shaft of a mechanical device passes through the sensor's shaft to directly couple the two. Of these three connection structures, the extended rotating shaft of the direct-connect sliding resistance sensor is a non-standard component, requiring customization from the manufacturer. This results in a high unit price, minimum order quantity requirements, a large inventory cost, and incompatibility with existing valve positioner feedback connectors, thus lacking versatility. For gear-driven sliding resistance sensors, gear meshing clearance will cause control hysteresis, and the radial force of gear meshing will cause gear jamming, tooth skipping, or slippage. Their mechanical structure is relatively complex, and wear will lead to a short product lifespan. For hollow shaft sliding resistance sensors, in environments with strong vibration and impact, their internal structure will be damaged, such as brush displacement, leading to increased measurement errors or sensor failure. Utility Model Content

[0004] Therefore, it is necessary to address the above-mentioned shortcomings by providing a valve position sensor connection structure for valve positioners that is compatible with existing valve positioner feedback connectors, can solve problems such as tooth skipping and slippage caused by gear transmission, has a long service life, and provides reliable detection.

[0005] A valve position sensor connection structure for a valve positioner includes:

[0006] Mounting support base is used to fix it on the bottom shell of the valve positioner. The mounting support base has insertion holes that penetrate its upper and lower surfaces.

[0007] A feedback shaft, inserted into a socket and rotatable relative to a mounting support, is axially positioned within the mounting support. The bottom of the feedback shaft is located outside the socket and forms a transmission section for connection to an external feedback connector. A axially extending groove is formed on the upper surface of the feedback shaft.

[0008] The sliding resistance sensor has a rotating shaft inserted into a limiting groove. The lower part of the rotating shaft is fixedly connected to the inner wall of the limiting groove and elastically engaged. The rotating shaft of the sliding resistance sensor rotates synchronously with the feedback shaft.

[0009] In one embodiment, the upper surface of the mounting support is provided with a slot communicating with the insertion hole, and the bottom surface of the slot and the part communicating with the insertion hole form a step; the valve position sensor connection structure also includes an adapter sleeve, which is inserted into the slot and fixedly connected to the inner wall of the slot. The adapter sleeve is provided with a mounting hole penetrating its upper and lower surfaces. The rotating shaft of the sliding resistance sensor rotates through the mounting hole and is inserted into the limiting groove. The circumferential side of the rotating shaft is provided with a fixing part fixedly connected to the inner wall of the mounting hole. The top of the feedback shaft is located in the slot and forms a limiting part that limits and cooperates with the bottom surface of the slot and the lower surface of the adapter sleeve.

[0010] In one embodiment, the valve position sensor connection structure further includes a connector, which includes an annular spring. The inner diameter of the annular spring gradually decreases and then gradually increases along its axial direction. The annular spring has a plurality of adjustment holes evenly distributed along its circumference on its annular side. Each adjustment hole extends along the axial direction of the annular spring. A first elastic connecting ring extending along its axial direction is formed at the top of the annular spring, and a second elastic connecting ring extending along its axial direction is formed at the bottom of the annular spring. The outer walls of the first and second elastic connecting rings abut against the inner wall of the limiting groove, and the inner wall of the annular spring elastically abuts against the outer wall of the rotating shaft.

[0011] In one embodiment, the upper inner wall of the slot is provided with a first internal thread, the annular side of the adapter sleeve is provided with a first external thread, and the top of the adapter sleeve protrudes radially to form a limiting platform. When the adapter sleeve is inserted into the slot, the first external thread and the first internal thread are threadedly engaged, and the lower surface of the limiting platform abuts against the edge of the slot opening. The inner wall of the mounting hole is provided with a second internal thread, and the annular side of the fixing part is provided with a second external thread. When the rotating shaft passes through the mounting hole, the second external thread and the second internal thread are threadedly engaged.

[0012] In one embodiment, the feedback shaft includes a shaft body inserted into a socket and a limiting head located in a slot and fixed to the top of the shaft body. The limiting groove penetrates the upper surface of the limiting head, and the lower part of the shaft body forms the transmission part. The diameter of the limiting head is larger than the inner diameter of the socket and forms the limiting part. The valve position sensor connection structure also includes a first washer, a second washer, and a third washer housed in the slot and stacked sequentially from top to bottom on the shaft body. The upper surface of the first washer abuts against the lower surface of the limiting head, and the lower surface of the third washer abuts against the bottom surface of the slot. The first washer and the third washer are both flat washers, and the second washer is a corrugated washer.

[0013] In one embodiment, the limiting groove is a stepped groove, including a large diameter portion and a small diameter portion located below and communicating with the large diameter portion. The outer contour shape of the lower part of the rotating shaft is adapted to the inner contour shape of the limiting groove, and the lower part of the rotating shaft is a flat block or sheet structure. The valve position sensor connection structure also includes a U-shaped spring piece sleeved and fixed to the lower part of the rotating shaft. When the rotating shaft is inserted into the small diameter portion of the limiting groove, the U-shaped spring piece elastically abuts against the inner wall of the small diameter portion of the limiting groove.

[0014] In one embodiment, a shoulder is formed on the outer side of the feedback shaft. A fourth washer and a fifth washer are sequentially provided from top to bottom between the shoulder and the upper surface of the mounting support. Both the fourth and fifth washers are sleeved on the feedback shaft. The lower surface of the fifth washer abuts against the upper surface of the mounting support, and the upper surface of the fifth washer elastically abuts against the lower surface of the fourth washer. The upper surface of the fourth washer elastically abuts against the shoulder. The fourth washer is a corrugated washer, and the fifth washer is a flat washer.

[0015] In one embodiment, the lower surface of the mounting support is provided with a slot coaxial with and communicating with the insertion hole. The shaft of the feedback shaft is provided with a first sealing groove above the slot and an annular groove below the slot. A first sealing ring that elastically abuts against the inner wall of the insertion hole is embedded in the first sealing groove. A retaining ring is embedded in the annular groove and protrudes from the annular groove. A sixth washer is also provided between the top surface of the slot and the annular groove. The sixth washer is sleeved on the shaft of the feedback shaft, and the upper surface of the sixth washer abuts against the top surface of the slot, and the lower surface of the sixth washer abuts against the upper surface of the retaining ring.

[0016] In one embodiment, the lower ring side of the mounting support protrudes outward to form an annular mounting disc, and the annular mounting disc is provided with a plurality of countersunk holes spaced apart through its upper and lower surfaces; or the annular mounting disc is integrally formed with the bottom shell of the valve positioner.

[0017] In one embodiment, a second sealing groove is provided on the annular side of the lower part of the mounting support, and a second sealing ring is embedded in the second sealing groove.

[0018] The valve position sensor connection structure for valve positioners according to this invention uses a sliding resistance sensor's rotating shaft to be fixedly connected to the feedback shaft with a flexible fit. This achieves a direct connection between the sliding resistance sensor and the feedback shaft without needing to lengthen the rotating shaft, making it compatible with existing valve positioner feedback connectors. This improves the versatility of the valve position sensor connection structure and expands its application range. Eliminating the gear transmission method solves the problems of control backlash caused by gear meshing clearance, and gear jamming, skipping, or slippage caused by radial force during gear meshing. Its simple structure reduces component wear and extends service life. The flexible fit between the rotating shaft and the feedback shaft buffers radial and axial impact forces, avoiding or reducing damage to the sensor's internal structure and ensuring detection accuracy and reliability. Attached Figure Description

[0019] Figure 1 This is a cross-sectional view of the valve position sensor connection structure in one embodiment of the present invention;

[0020] Figure 2 This is an exploded structural diagram of the valve position sensor connection structure in one embodiment of the present invention;

[0021] Figure 3 This is an exploded view of the valve position sensor connection structure within the valve positioner in another embodiment of the present invention;

[0022] Figure 4 for Figure 3 The cross-sectional view of the valve position sensor connection structure after installation inside the valve positioner in the embodiment shown;

[0023] Figure 5 for Figure 4 A partially enlarged structural diagram of part A in the illustrated embodiment. Detailed Implementation

[0024] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0025] Please combine Figure 1 and Figure 2 This utility model discloses a valve position sensor connection structure for a valve positioner. The structure includes a mounting support 100, a feedback shaft 300, and a sliding resistance sensor 400. The mounting support 100 is fixed to the bottom shell of the valve positioner and has insertion holes 110 extending through its upper and lower surfaces. The feedback shaft 300 is inserted into the insertion hole 110 and can rotate relative to the mounting support 100. The feedback shaft 300 is also axially positioned within the mounting support 100, thus limiting its position while simultaneously rotating the rotating shaft 410 of the sliding resistance sensor 400, preventing it from detaching from the mounting support 100. The bottom of the feedback shaft 300 is located outside the insertion hole 110 and forms a transmission part for connection with an external feedback connector. The upper surface of the feedback shaft 300 has a limiting groove 310 extending axially. The rotating shaft 410 of the sliding resistance sensor 400 is inserted into the limiting groove 310. The lower part of the rotating shaft 410 is fixedly connected to and elastically engaged with the inner wall of the limiting groove 310, and the rotating shaft 410 of the sliding resistance sensor 400 rotates synchronously with the feedback shaft 300. In this embodiment, the lower part of the feedback shaft 300 is connected to the feedback connector, and the upper part of the feedback shaft 300 is limited and engaged with the mounting support 100 and elastically engaged with the rotating shaft 410 of the sliding resistance sensor 400. Thus, when the pneumatic actuator operates, it drives the feedback shaft 300 to rotate via the feedback connector, which in turn drives the rotating shaft 410 of the sliding resistance sensor 400 to rotate, thereby enabling the sliding resistance sensor 400 to send an electrical signal to the control module of the valve positioner.

[0026] The mounting support 100 is used to support the feedback shaft 300 and the sliding resistance sensor 400, thereby enabling the positioning of each component within the valve positioner. The mounting support 100 can be fixed to the bottom shell of the valve positioner by welding or screw connection. In this embodiment, the annular side of the lower part of the mounting support 100 protrudes outward to form an annular mounting plate 130. The lower surface of the annular mounting plate 130 is flush with the lower surface of the mounting support 100. The annular mounting plate 130 has multiple countersunk holes 140 spaced apart, penetrating its upper and lower surfaces. By inserting multiple screws through each countersunk hole 140 and into the bottom shell of the valve positioner, the mounting support 100 can be fixed to the bottom shell of the valve positioner. In another embodiment, the annular mounting plate 130 and the bottom shell of the valve positioner are integrally formed.

[0027] Please combine further Figure 1-2 In one embodiment, the upper surface of the mounting support 100 is provided with a slot 120 communicating with the insertion hole 110. The bottom surface of the slot 120 and the part communicating with the insertion hole 110 form a step. It can also be understood that the insertion hole 110 and the slot 120 together form a two-stage stepped hole penetrating the upper and lower surfaces of the mounting support 100. The slot 120 is the large-diameter part of the two-stage stepped hole, and the insertion hole 110 is the small-diameter part of the two-stage stepped hole. The valve position sensor connection structure also includes an adapter sleeve 200. The adapter sleeve 200 is inserted into the slot 120 and fixedly connected to the inner wall of the slot 120. The adapter sleeve 200 is provided with a mounting hole 210 penetrating its upper and lower surfaces. The adapter sleeve 200 is used to provide a connection part between the sliding resistance sensor 400 and the mounting support 100, so as to realize the installation of the sliding resistance sensor 400 on the mounting support 100 and avoid relative displacement between the sliding resistance sensor 400 and the mounting support 100. The rotating shaft 410 of the sliding resistance sensor 400 rotatably passes through the mounting hole 210 and is inserted into the limiting groove 310. A fixing part is provided on the circumferential side of the rotating shaft 410, which is fixedly connected to the inner wall of the mounting hole 210. This fixing part limits the axial position of the rotating shaft 410 along the rotating shaft. Thus, while limiting the axial position of the rotating shaft 410 by connecting the fixing part to the inner wall of the mounting hole 210, it ensures that the rotating shaft 410 can rotate under the drive of the feedback shaft. The top of the feedback shaft 300 is located within the slot 120 and forms a limiting part that limits and cooperates with the bottom surface of the slot 120 and the lower surface of the adapter sleeve 200.

[0028] In this embodiment, the adapter sleeve 200 is fixedly connected to the inner wall of the slot 120 to fix the sliding resistance sensor 400 on the mounting support 100. In one embodiment, the outer ring side of the adapter sleeve 200 is tightly fitted to the inner wall of the slot 120. In another embodiment, the outer ring side of the adapter sleeve 200 is welded to the inner wall of the slot 120. In yet another embodiment, the outer ring side of the adapter sleeve 200 is bonded to the inner wall of the slot 120. Preferably, the outer ring side of the adapter sleeve 200 is threadedly connected to the inner wall of the slot 120. Specifically, the upper inner wall of the slot 120 is provided with a first internal thread 121, the ring side of the adapter sleeve 200 is provided with a first external thread 220, and the top of the adapter sleeve 200 protrudes radially to form a limiting platform 230. When the adapter sleeve 200 is inserted into the slot 120, the first external thread 220 and the first internal thread 121 are threadedly engaged, and the lower surface of the limiting platform 230 abuts against the edge of the slot opening of the slot 120. Thus, with the first internal thread 121 and the first external thread 220 threadedly engaged, the maximum insertion depth of the adapter sleeve 200 in the slot 120 is limited by the contact between the limiting platform 230 and the edge of the slot 120, thereby preventing damage to the feedback shaft 300 caused by the lower part of the adapter sleeve 200 pressing against it. Furthermore, in this embodiment, at least a pair of limiting planes 240 are symmetrically arranged on the outer ring surface of the limiting platform 230 of the adapter sleeve 200. These limiting planes 240 provide a gripping portion for the adapter sleeve 200, so that when the adapter sleeve 200 is assembled with the mounting support 100, by gripping the symmetrical limiting planes 240 on the adapter sleeve 200 and rotating the adapter sleeve 200, the first external thread 220 and the first internal thread 121 can be threadedly engaged, reducing the installation difficulty of the adapter sleeve 200.

[0029] The rotating shaft 410 of the sliding resistance sensor 400 rotates with the feedback shaft 300 to collect the action signal of the pneumatic actuator. In one embodiment, the annular side of the fixing part is tightly fitted to the inner wall of the mounting hole 210. In another embodiment, the annular side of the fixing part is welded to the inner wall of the mounting hole 210. In yet another embodiment, the annular side of the fixing part is bonded to the inner wall of the mounting hole 210. Preferably, the annular side of the fixing part is threaded to the inner wall of the mounting hole 210. Specifically, the inner wall of the mounting hole 210 is provided with a second internal thread 211, and the annular side of the fixing part is provided with a second external thread 420. When the rotating shaft 410 passes through the mounting hole 210, the second external thread 420 and the second internal thread 211 are threadedly engaged. Thus, by simply inserting the rotating shaft 410 into the mounting hole 210 and tightening the fixing part to the inner wall of the mounting hole 210, the limiting engagement between the rotating shaft 410 and the adapter sleeve 200 can be achieved.

[0030] In this embodiment, the helical direction of the first external thread 220 is opposite to that of the second external thread 420, so that during the process of tightening the adapter sleeve 200 with the fixing part and rotating the adapter sleeve 200 relative to the mounting support 100 to lock it, the sliding resistance sensor 400 can rotate synchronously with the adapter sleeve 200, so as to avoid the problem of the fixing part of the sliding resistance sensor 400 loosening relative to the adapter sleeve 200 when the adapter sleeve 200 is tightened with the mounting support 100, thereby causing the sliding resistance sensor 400 to fall off the adapter sleeve 200.

[0031] In order to achieve the limiting fit between the feedback shaft 300 and the mounting support 100, in this embodiment, the feedback shaft 300 includes a shaft body 320 inserted into the insertion hole 110, a limiting head 330 located in the slot 120 and fixed to the top of the shaft body 320, a limiting groove 310 penetrating the upper surface of the limiting head 330, a transmission part formed at the lower part of the shaft body 320, and the diameter of the limiting head 330 is larger than the inner diameter of the insertion hole 110 and forms a limiting part. Furthermore, the valve position sensor connection structure also includes a first washer 500, a second washer 600, and a third washer 700, which are housed in the slot 120 and stacked sequentially from top to bottom on the shaft 320. The upper surface of the first washer 500 abuts against the lower surface of the limiting head 330, and the lower surface of the third washer 700 abuts against the bottom surface of the slot 120. Both the first washer 500 and the third washer 700 are flat washers, while the second washer 600 is a corrugated washer. The upper surface of the second washer 600 elastically abuts against the lower surface of the first washer 500, and the lower surface of the second washer 600 elastically abuts against the upper surface of the third washer 700.

[0032] To achieve synchronous rotation of the rotating shaft 410 with the feedback shaft 300 and to provide shock absorption protection for the rotating shaft 410, in this embodiment, the valve position sensor connection structure further includes a connector 900. The connector 900 includes an annular spring 910, the inner diameter of which gradually decreases and then gradually increases along its axial direction. The annular spring 910 has multiple adjustment holes 920 evenly distributed along its circumference on its annular side. Each adjustment hole 920 extends along the axial direction of the annular spring 910. A first elastic connecting ring 930 extending along its axial direction is formed at the top of the annular spring 910, and a second elastic connecting ring 940 extending along its axial direction is formed at the bottom of the annular spring 910. The outer walls of the first elastic connecting ring 930 and the second elastic connecting ring 940 abut against the inner wall of the limiting groove 310, and the inner wall of the annular spring 910 elastically abuts against the outer wall of the rotating shaft 410. It can also be understood that the annular spring 910 has a waist-drum shaped structure, which can be obtained by bending the middle of the annular side of the cylindrical spring towards its axis. Preferably, in this embodiment, the minimum inner diameter of the annular spring 910 is smaller than the diameter of the lower part of the rotating shaft 410. Thus, when the lower part of the rotating shaft 410 is inserted into the annular spring 910, the middle of the inner wall of the annular spring 910 will press the rotating shaft 410, thereby achieving radial limiting of the rotating shaft 410. In this case, since the first elastic connecting ring 930 at the top of the annular spring 910 and the second elastic connecting ring 940 at the bottom abut against the inner wall of the limiting groove 310, the rotating shaft 410 and the feedback shaft 300 can be fixedly connected through the connector 900, so that the two can rotate synchronously. At the same time, the elastic abutment of the annular spring 910 against the rotating shaft 410 can buffer the axial and radial impacts on the rotating shaft 410, reduce damage to the internal structure of the sensor, such as brush displacement and wear of the resistive element, ensure measurement accuracy, avoid sensor failure, and improve the service life of the sensor. By opening an adjustment hole 920 on the annular spring 910, the elastic coefficient of the annular spring 910 can be changed, its elastic performance can be improved, and thus the damping effect of the annular spring 910 on the rotating shaft 410 can be improved.

[0033] Please combine Figure 3-5In another embodiment, the limiting groove 310 is a stepped groove, including a large-diameter portion and a small-diameter portion located below and communicating with the large-diameter portion. The outer contour shape of the lower part of the rotating shaft 410 is adapted to the inner contour shape of the limiting groove 310, and the lower part of the rotating shaft 410 is a flat block or sheet structure. The valve position sensor connection structure also includes a U-shaped spring piece 950 sleeved and fixed to the lower part of the rotating shaft 410. When the rotating shaft 410 is inserted into the small-diameter portion of the limiting groove 310, the U-shaped spring piece 950 elastically abuts against the inner wall of the small-diameter portion of the limiting groove 310. In this embodiment, the adapter sleeve is eliminated, the lower part of the rotating shaft 410 is a flat structure, and the U-shaped spring piece 950 is a U-shaped retaining spring fixed on the flat structure. In other embodiments, a flat connecting component is sleeved on the lower part of the rotating shaft 410 to fix the U-shaped spring piece 950 on the flat connecting component. By attaching a U-shaped spring piece 950 to the bottom of the rotating shaft 410, and by elastically abutting the U-shaped spring piece 950 against the inner wall of the limiting groove 310, the radial limiting of the rotating shaft 410 can be achieved. Thus, when the feedback shaft 300 rotates, the feedback shaft 300 will drive the rotating shaft 410 to rotate synchronously via the U-shaped spring piece 950. At the same time, the elastic abutting between the U-shaped spring piece 950 and the inner wall of the limiting groove 310 achieves shock absorption protection for the rotating shaft 410.

[0034] The outer surface of the feedback shaft 300 forms a shoulder 301. A fourth washer 960 and a fifth washer 970 are sequentially arranged from top to bottom between the shoulder 301 and the upper surface of the mounting support 100. Both the fourth washer 960 and the fifth washer 970 are fitted onto the feedback shaft 300. The lower surface of the fifth washer 970 abuts against the upper surface of the mounting support 100 (the edge of the top opening of the insertion hole), and the upper surface of the fifth washer 970 elastically abuts against the lower surface of the fourth washer 960. The upper surface of the fourth washer 960 elastically abuts against the shoulder 301. The fourth washer 960 is a corrugated washer, and the fifth washer 970 is a flat washer. Thus, the cooperation of the fourth washer 960 and the fifth washer 970 limits the movement of the feedback shaft 300, preventing it from wobbling relative to the mounting support 100.

[0035] Furthermore, in this embodiment, a copper sleeve 980 is inserted into the insertion hole 110 of the mounting support 100. The outer ring surface of the copper sleeve 980 abuts against the inner side of the insertion hole 110. The feedback shaft 300 passes through the copper sleeve 980 and rotates with the inner wall of the copper sleeve 980. The top of the copper sleeve 980 is provided with a limiting ring 981 that abuts against the edge of the top opening of the insertion hole 110. When a fourth washer 960 and a fifth washer 970 are provided, the lower surface of the fifth washer 970 abuts against the upper surface of the limiting ring 981. By providing the copper sleeve 980, the feedback shaft 300 can be protected, and the feedback shaft 300 can be adapted to the insertion hole size of the insertion hole 110 of the mounting support 100.

[0036] The lower surface of the mounting support 100 is provided with a slot 150 that is coaxial with and connected to the insertion hole 110. The shaft body 320 of the feedback shaft 300 is provided with a first sealing groove 340 above the slot 150 and an annular groove 350 below the slot 150. The first sealing groove 340 is fitted with a first sealing ring 360 that elastically abuts against the inner wall of the insertion hole 110 or the inner wall of the copper sleeve 980. The annular groove 350 is fitted with a retaining ring 370 that protrudes from the annular groove 350. A sixth washer 800 is also provided between the top surface of the slot 150 and the annular groove 350. The sixth washer 800 is fitted onto the shaft body 320 of the feedback shaft 300, and the upper surface of the sixth washer 800 abuts against the top surface of the slot 150 or the bottom surface of the copper sleeve 980, and the lower surface of the sixth washer 800 abuts against the upper surface of the retaining ring 370. In this embodiment, by setting a first washer 500, a second washer 600, and a third washer 700 between the limiting head 330 and the bottom surface of the slot 120, a limiting connection is achieved between the top of the feedback shaft 300 and the mounting support 100. By setting a sixth washer 800 between the retaining ring 370 and the top surface of the retaining groove 150, a limiting connection is achieved between the bottom of the feedback shaft 300 and the mounting support 100. Thus, through the combined action of the limiting head 330, the retaining ring 370, and the various washers, the feedback shaft 300 is limited to prevent it from wobbling relative to the mounting support 100 along its axial direction. By creating a first sealing groove 340 on the feedback shaft 300 and embedding a first sealing ring 360 within the first sealing groove 340, external oil contaminants can be prevented from entering the slot 120 through the bottom of the insertion hole 110, thus preventing contamination of the connection between the rotating shaft 410 and the feedback shaft 300.

[0037] Furthermore, a second sealing groove 160 is provided on the annular side of the lower part of the mounting support 100, and a second sealing ring 170 is embedded in the second sealing groove 160. Preferably, the lower edge of the groove opening of the second sealing groove 160 is flush with the upper surface of the annular mounting plate 130. When the mounting support 100 is installed with the bottom shell of the valve positioner, the second sealing ring 170 is used to elastically abut against the other components inside the bottom shell to achieve sealing protection for the entire valve position sensor connection structure.

[0038] This section uses a valve position sensor connection structure with an adapter sleeve as an example to illustrate its assembly process. During the assembly of the valve position sensor connection structure, firstly, the adapter sleeve 200 is screwed onto the fixed part outside the rotating shaft 410 of the sliding resistance sensor 400. Then, the connector 900 is pressed into the feedback shaft 300 (during the pressing process, the first elastic connecting ring 930 and the second elastic connecting ring 940 deform so that after entering the limiting groove 310, they can abut against the inner wall of the limiting groove 310). The first sealing ring 360 is then fitted into the first sealing groove 340 of the feedback shaft 300. A special tooling is used to ensure that the center position of the sliding resistance sensor 400 is consistent with the flat position on the feedback shaft 300. Finally, the rotating shaft 410 of the sliding resistance sensor 400 is inserted into the connector 900. First washer 500, second washer 600, and third washer 700 are sequentially fitted onto the feedback shaft 300. Then, the assembled components are placed into the mounting support 100, and the adapter sleeve 200 is tightened. Sixth washer 800 and retaining ring 370 are sequentially installed at the lower part of the feedback shaft 300. Second sealing ring 170 is installed on the outside of the mounting support 100. The assembly is now complete and ready for storage. During sensor installation, the assembled valve position sensor connection structure is fixed to the bottom housing of the valve positioner using four countersunk screws passing through the four countersunk holes 140 on the mounting support 100. The sensor signal is connected to the valve positioner mainboard (control module) via a cable or crimped terminal block.

[0039] The valve position sensor connection structure for a valve positioner according to this invention uses a sliding resistance sensor 400 with a rotating shaft 410 and a feedback shaft 300 that are fixedly connected and elastically fitted. This direct connection between the sliding resistance sensor 400 and the feedback shaft 300 eliminates the need to lengthen the rotating shaft 410, making it compatible with existing valve positioner feedback connectors. This improves the versatility of the valve position sensor connection structure and expands its application range. Eliminating the gear transmission method solves the problems of control backlash caused by gear meshing clearance, and gear jamming, skipping, or slippage caused by radial force during gear meshing. Its simple structure reduces wear on components and extends service life. The elastic fit between the rotating shaft 410 and the feedback shaft 300 buffers radial and axial impact forces, avoiding or reducing damage to the internal structure of the sensor and ensuring the accuracy and reliability of the detection.

[0040] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0041] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A valve position sensor connection structure for a valve positioner, characterized by, The valve position sensor connecting structure comprises: a mounting support fixed on a bottom shell of a valve positioner, the mounting support being provided with a through hole penetrating through upper and lower surfaces thereof; a feedback shaft inserted into the through hole and rotatable relative to the mounting support, the feedback shaft being limited in position along an axial direction thereof relative to the mounting support, a bottom of the feedback shaft being located outside the through hole and forming a transmission part for connecting with an external feedback connecting member, an upper surface of the feedback shaft being provided with a limiting groove extending along the axial direction thereof; and a sliding resistance sensor, a rotating shaft of the sliding resistance sensor being inserted into the limiting groove, a lower part of the rotating shaft being fixedly connected with an inner wall of the limiting groove in an elastic manner, and the rotating shaft of the sliding resistance sensor being synchronously rotatable with the feedback shaft.

2. The valve position sensor connection structure according to claim 1, characterized by An insertion slot is provided on an upper surface of the mounting support and communicates with the through hole, a bottom surface of the insertion slot and a communicating part of the through hole forming a step; the valve position sensor connecting structure further comprises an adapter sleeve, the adapter sleeve being inserted into the insertion slot and fixedly connected with an inner wall of the insertion slot, the adapter sleeve being provided with a mounting hole penetrating through upper and lower surfaces thereof, the rotating shaft of the sliding resistance sensor being rotatable through the mounting hole and inserted into the limiting groove, a ring side of the rotating shaft being provided with a fixed part fixedly connected with an inner wall of the mounting hole, a top of the feedback shaft being located in the insertion slot and forming a limiting part limited in position relative to a bottom surface of the insertion slot and a lower surface of the adapter sleeve.

3. The valve position sensor connection structure according to claim 2, characterized by The valve position sensor connecting structure further comprises a connector, the connector comprising a ring-shaped elastic sheet, an inner diameter of the ring-shaped elastic sheet gradually decreasing and then gradually increasing along an axial direction thereof, a ring side surface of the ring-shaped elastic sheet being provided with a plurality of adjusting holes uniformly distributed along a circumferential direction thereof, each adjusting hole extending along the axial direction of the ring-shaped elastic sheet, a top of the ring-shaped elastic sheet forming a first elastic connecting ring extending along the axial direction thereof, and a bottom of the ring-shaped elastic sheet forming a second elastic connecting ring extending along the axial direction thereof; outer walls of the first and second elastic connecting rings abutting against an inner wall of the limiting groove, and an inner wall of the ring-shaped elastic sheet elastically abutting against an outer wall of the rotating shaft.

4. The valve position sensor connection structure according to claim 2, characterized by An upper inner thread is provided on an inner wall of an upper part of the insertion slot, a ring side surface of the adapter sleeve is provided with a first outer thread, a top of the adapter sleeve is protruded along a radial direction thereof to form a limiting step, when the adapter sleeve is inserted into the insertion slot, the first outer thread is threadedly connected with the first inner thread, and a lower surface of the limiting step abuts against an edge of a slot opening of the insertion slot; an inner wall of the mounting hole is provided with a second inner thread, a ring side surface of the fixed part is provided with a second outer thread, when the rotating shaft passes through the mounting hole, the second outer thread is threadedly connected with the second inner thread.

5. The valve position sensor connection structure according to claim 2, characterized by The feedback shaft comprises a shaft body inserted into the through hole, a limiting head fixedly connected with a top of the shaft body and located in the insertion slot, the limiting groove penetrating through an upper surface of the limiting head, a lower part of the shaft body forming the transmission part, a diameter of the limiting head being greater than an inner diameter of the through hole and forming the limiting part; the valve position sensor connecting structure further comprises a first gasket, a second gasket and a third gasket sequentially stacked from top to bottom and sleeved on the shaft body, an upper surface of the first gasket abutting against a lower surface of the limiting head, a lower surface of the third gasket abutting against a bottom surface of the insertion slot, and the first and third gaskets being flat gaskets, and the second gasket being a corrugated gasket.

6. The valve position sensor connection structure according to claim 1, characterized by The limiting groove is a stepped groove, comprising a large-diameter part and a small-diameter part below the large-diameter part and communicating with the large-diameter part, the outer contour shape of the lower part of the rotating shaft is adapted to the inner contour shape of the limiting groove, and the lower part of the rotating shaft is a flat block or a sheet structure; the valve position sensor connecting structure further comprises a U-shaped spring sheet sleeved and fixed on the lower part of the rotating shaft, and when the rotating shaft is inserted into the small-diameter part of the limiting groove, the U-shaped spring sheet elastically abuts against the inner wall of the small-diameter part of the limiting groove.

7. The valve position sensor connection structure according to claim 6, characterized by The outer side surface of the feedback shaft forms a shaft shoulder part, and a fourth gasket and a fifth gasket are sequentially arranged from top to bottom between the shaft shoulder part and the upper surface of the mounting support seat, both the fourth gasket and the fifth gasket are sleeved on the feedback shaft, the lower surface of the fifth gasket abuts against the upper surface of the mounting support seat, the upper surface of the fifth gasket elastically abuts against the lower surface of the fourth gasket, the upper surface of the fourth gasket elastically abuts against the shaft shoulder part, the fourth gasket is a corrugated gasket, and the fifth gasket is a flat gasket.

8. The valve position sensor connection structure according to any one of claims 1 to 7, characterized by The lower surface of the mounting support seat is provided with a clamping groove coaxial with and communicating with the insertion hole, the shaft body of the feedback shaft is provided with a first sealing groove above the clamping groove and an annular groove below the clamping groove, the first sealing groove is embedded with a first sealing ring elastically abutting against the inner wall of the insertion hole, and the annular groove is embedded with a clamping ring protruding from the annular groove, and a sixth gasket is further arranged between the top surface of the clamping groove and the annular groove, the sixth gasket is sleeved on the shaft body of the feedback shaft, the upper surface of the sixth gasket abuts against the top surface of the clamping groove, and the lower surface of the sixth gasket abuts against the upper surface of the clamping ring.

9. The valve position sensor connection structure according to claim 8, characterized by The ring side surface of the lower part of the mounting support seat protrudes outward to form an annular mounting disc, and a plurality of through holes are arranged on the annular mounting disc and spaced apart from each other; or the annular mounting disc is integrally formed with the bottom shell of the valve positioner.

10. The valve position sensor connection structure according to claim 8, characterized by The ring side surface of the lower part of the mounting support seat is provided with a second sealing groove, and the second sealing groove is embedded with a second sealing ring.

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