Transmission mechanism of circular valve

Abstract

The utility model discloses a transmission mechanism of a circular valve, which comprises a transmission strip, and the transmission strip synchronously drives a plurality of gears to enable a plurality of valve rods of the circular valve to rotate at the same time to adjust flow; the transmission mechanism further comprises a plurality of gear sets and a plurality of parallel axial driving shafts, the gear sets are arranged on the outer side of the valve body and located between the driving shafts and the valve rods, the gear sets drive the corresponding valve rods, and the gear sets are driven by the corresponding driving shafts. A driving wheel is fixed on the driving shaft, and the driving wheel is meshed with the transmission strip and is synchronously driven by the transmission strip; furthermore, the design of a bevel gear set, the design of a synchronous belt, an output shaft with a sliding pair and a torque sensor are adopted. Compared with an existing transmission mechanism of a circular valve with valve rods distributed in a fan shape, the transmission mechanism is easier to maintain while the transmission precision is guaranteed; compared with a transmission mechanism of an existing round valve with parallel valve rods, the transmission mechanism is smaller in occupied space.

Description

Technical Field

[0001] This invention relates to the field of industrial and civil fluid control, and specifically to a transmission mechanism for a circular valve. Background Technology

[0002] In industrial and civil fluid control applications, circular valves, often in butterfly form, can be categorized into single-stem or multi-stem types. In certain flow fields, excessive eddies and uneven static pressure distribution increase the additional torque exerted on a single stem by the fluid during operation, leading to severe bushing wear and valve vane deformation under certain conditions. Multi-stem butterfly valves allow for thinner valve bodies and superior pressure resistance. More importantly, they enable a more even distribution of flow clearance, making them suitable for high-precision fluid regulation applications, such as fan inlet airflow regulation and variable air volume valves.

[0003] Multi-stem circular valves can be categorized by stem shape into parallel or fan-shaped distributions. A circular valve with parallel stem distribution, such as the design in CN 214578911 U, has the drawback of a large space-consuming transmission mechanism; furthermore, in multi-leaf designs, the different sizes of the valve leaves make standardized production difficult.

[0004] The multiple valve blades of a sector-shaped damper have the same shape and are distributed radially. The transmission components of a sector-shaped damper can be of various types. For example, the sector-shaped regulating valve with bevel gear transmission disclosed in PCT WO2008 / 147023A2 has the problem that the transmission mechanism is located inside the valve body, resulting in stress concentration on the gears, making them prone to wear and inconvenient for maintenance. Another example is the sector-shaped damper disclosed in CN 211501049 U, which uses a connecting rod transmission located outside the circular valve body. Due to the use of a sliding pin design, the adjustment accuracy of the transmission mechanism is relatively low under circular design conditions.

[0005] In some engineering applications, there is a need for a better transmission mechanism for multi-stem circular valves that can ensure sufficient transmission accuracy while being easy to maintain, occupy little space, and be easy to manufacture. Summary of the Invention

[0006] This invention designs a transmission mechanism for a circular valve, which can be used in circular valves in industrial and civil fluid control fields.

[0007] The technical solution adopted is:

[0008] The system includes a transmission bar that synchronously drives multiple gears to rotate multiple valve stems of the circular valve simultaneously to regulate flow. The transmission mechanism also includes multiple gear sets and multiple parallel axial drive shafts. The gear sets are located outside the valve body and between the drive shafts and valve stems. The gear sets drive the corresponding valve stems and are driven by the corresponding drive shafts. Drive wheels are fixed on the drive shafts and mesh with the transmission bar for synchronous transmission.

[0009] Furthermore, the gear set is used to transmit torque and change the direction of torque.

[0010] Furthermore, each of the gear sets includes a pair of bevel gears that mesh with each other to form a 90-degree axial angle.

[0011] Furthermore, one drive wheel in the transmission mechanism is used for active transmission.

[0012] Furthermore, the gear set in the transmission mechanism includes an output shaft, and the output shaft and valve stem are connected by a sliding pair.

[0013] Furthermore, the transmission bar in the transmission mechanism is an arc-shaped rack.

[0014] Furthermore, the transmission bar in the transmission mechanism is a synchronous belt.

[0015] Furthermore, the core wire of the synchronous belt in the transmission mechanism is a steel wire.

[0016] Furthermore, the working surface of the synchronous belt in the transmission mechanism is a circular arc tooth.

[0017] Furthermore, at least one drive shaft in the transmission mechanism is equipped with a torque sensor.

[0018] Compared to the existing transmission mechanism of circular valves with fan-shaped valve stem distribution, the above design ensures transmission accuracy while being easier to maintain; it also occupies less space compared to the existing transmission mechanism of circular valves with parallel valve stem distribution.

[0019] Furthermore, the transmission mechanism includes at least one mounting module; the mounting module includes the gear set, related fixing brackets, and is pre-manufactured; this design improves manufacturing efficiency and manufacturing precision. Attached Figure Description

[0020] Figure 1 Example of a multi-stem circular air valve

[0021] Figure 2 Example of a bevel gear installation diagram for a multi-stem circular air valve.

[0022] Figure 3 Example of a multi-stem circular water valve

[0023] Figure 4 Example of an arc-shaped rack and pinion drive

[0024] Figure 5 Example 1 of synchronous belt drive

[0025] Figure 6 Example 2 of synchronous belt drive

[0026] Figure 7 Example of installing modules Detailed Implementation

[0027] The technical solutions in the embodiments of this application will be described in detail below with reference to the accompanying drawings. This invention is designed for circular valve bodies, referring to valve bodies with a circular, elliptical, or similar elliptical cross-section. For elliptical or similar elliptical cross-sections, the axial direction refers to the direction formed by the center points of the cross-section. In actual manufacturing, this invention still applies to cases of local deformation of the cross-section.

[0028] Figure 1 As an example of a multi-stem circular valve, the multi-leaf circular valve has 30 stems, each stem 9 equipped with a valve blade 10. An internal valve partition plate 12 is also provided, fixed to the valve body and securing the central limiting block 11. Both ends of the valve stem are respectively limited by the limiting block 11 and the valve body 8. The portion of the valve stem passing through the valve body 8 can utilize a sliding bearing. In practical engineering, this reduces the number of valve stems, increasing practicality and economy under different operating conditions.

[0029] The example shows 6 damper partitions. In actual engineering, more damper partitions can be added so that the two sides of a single valve stem are damper partitions. When a single valve leaf is closed, the damper partitions on both sides form a sealing boundary. The damper partitions can be further designed by using a reasonable contour or lining the damper partitions with materials such as rubber, so that a seal is formed when the valve leaf is closed.

[0030] Figure 2 This is a schematic diagram of bevel gear installation for a multi-stem circular valve. In the diagram, 30 first bevel gears are distributed and installed on the corresponding valve stems 9. In actual engineering, the number of bevel gears is reduced accordingly based on the number of valve stems.

[0031] Figure 3 This is an example of a multi-stem circular water valve, which employs a design with multiple butterfly valve vanes. The valve body 8 and valve seat 20 are integral components, with the valve seat's sealing surface layer overlaid with a corrosion-resistant alloy material. The valve seat has six mutually separated flow chambers, each equipped with a corresponding valve stem 9 and valve vane 10. Rotation of the valve stem 9 drives the valve vane fixed thereon for adjustment. The inner wall sealing surface of each flow chamber of the valve seat 20 has a streamlined design, and the corresponding valve vane adopts the same profile. Individual valve vanes and valve stems are connected by tapered pins for easy installation, and the valve stem has a bushing and O-ring at the point where it passes through the valve body.

[0032] A limit block 11 is provided at the center of the valve seat for limiting the position of a single valve stem. The limit block 11 can be prefabricated by machining the shaft positioning hole, and then welding the limit block into the valve seat. When the valve stem is limited in the limit block, bushings, O-rings, or other technical measures can be used. The valve stem is on the outside of the valve body, and the transmission design can be carried out using any of the following methods, which has good precision and practicality.

[0033] The multi-stem circular water valve design described above offers numerous advantages over traditional butterfly valves. Existing large-diameter valves employ a single valve plate structure, which can lead to valve body deformation in practical applications, affecting the valve plate's sealing and operation. Furthermore, under certain operating conditions, the valve stem experiences excessive thrust when closed in large-diameter valves, causing wear on the bushing, resulting in leakage and reduced coaxiality between the valve stem and actuator, leading to serious malfunctions. By employing appropriate valve plate shapes and manufacturing processes, these problems can be significantly improved with the multi-stem circular water valve. The multi-plate design reduces the driving torque of a single valve stem, improving operational reliability. For large-diameter valves, increasing the axial width of the valve seat allows for a substantial reduction in the seat thickness between valve plates, further reducing fluid resistance and enhancing structural reliability.

[0034] The valve seat of the aforementioned multi-stem circular water valve can be designed in a variety of non-metallic materials, and its sealing surface shape can be optimized. Various methods can be used to fix it to the valve body.

[0035] This invention relates to Figure 1 The stem of the multi-leaf circular valve in the example is designed with a gear set. Figure 4 As shown, each of the four valve stems 9 has a gear set at its outer end. Each gear set is driven by a driven shaft 6 parallel to the axial direction. The driven shaft 6 is driven by an arc-shaped rack 401 via a driven wheel fixed thereon. Each gear set includes a first bevel gear 1 fixed to the valve stem 9 and a second bevel gear 2 fixed to the driven shaft. The two bevel gears mesh to form a 90-degree axial angle. A portion of the valve body surface near the outer end of the valve stem 9 can be machined into a flat-mounted sliding bearing, and multiple arc-shaped dust covers can be installed to protect the bevel gear sets. In this invention, the gear set refers to multiple gears between a single drive shaft and a single valve stem 9, which mesh with each other to transmit torque and change the direction of torque. In actual engineering, different gear set designs can be used to achieve different transmission ratios. The outer end of the valve stem refers to the end of the valve stem closest to the valve body 8.

[0036] The first bevel gear 1 and the second bevel gear 2 can be involute bevel gears, made of POM or nylon. For high torque applications, metal can be used.

[0037] In the example, the bevel gears in each gear set all adopt a 1 module, 15-tooth design. In actual engineering, different numbers of teeth can be used to achieve different transmission ratios. By using different transmission ratios, control accuracy can be optimized and service life can be improved.

[0038] In this example, a single gear set converts axial gear rotation into radial valve stem rotation. The second bevel gear is fixed to the driven shaft 6, which meshes with the arc-shaped rack via the driven wheel 3. After the arc-shaped rack is partially restrained, it can be driven by a motor via a gear or connecting rod mechanism, thus generating rotation about the valve body axis, driving the rotation of all driven shafts, and achieving flow regulation. In this design, the external driving torque is distributed across the arc-shaped rack, resulting in superior stress distribution characteristics. The driven wheel in the diagram can be an involute spur gear.

[0039] Figure 4 This is only a partial illustration of the transmission of a circular valve. The entire transmission of the circular valve can be manufactured according to the illustration. A bracket can be added to the valve body, and a fixed radial or axial mounting plate can be added. Thrust bearings can be installed on the drive shaft and valve stem according to the illustration in the mounting module. An output shaft can be added so that the valve stem and the output shaft form a sliding pair connection.

[0040] The arc-shaped rack 401 can be designed as a segment of an arc to achieve flow regulation in a local area of ​​a circular valve.

[0041] The aforementioned arc-shaped rack 401 can be replaced by a synchronous belt 402 for more flexible design. Synchronous belt drive is a typical meshing transmission method, with a toothed working surface. Its transmission principle involves the sequential meshing of the pulley grooves with the convex teeth on the inner surface of the belt to transmit motion and power. There is no relative slippage between the belt and the pulley, thus enabling synchronous, slip-free movement between the driving and driven pulleys. Both the arc-shaped rack and the synchronous belt are components with partially arc-shaped sections and toothed working surfaces, and can be collectively referred to as transmission bars. The teeth in the transmission bar are used to transmit driving force and can adopt various tooth shapes, such as trapezoidal teeth.

[0042] The drive bar can also be designed using a chain and sprocket, with the sprocket as the drive wheel and the chain as the drive bar. The principle is as described above.

[0043] Figure 5 exist Figure 4 Based on the design changes, a partial schematic of the transmission part of the circular valve using a synchronous belt design is shown, which can be used to manufacture the overall transmission of the circular valve.

[0044] The example uses a 3M series arc-tooth synchronous pulley and synchronous belt with a 3mm pitch. Two smooth pulleys 5 with bearings are used as tensioners to adjust the tension of the synchronous belt 402. The tensioners 5 are fixed and adjusted by a radial mounting plate 13 and a locking nut 14. In actual engineering, a tensioning mechanism can be added to optimize the direction and wrap angle of the synchronous belt. The driven pulley 3 in the figure is an aluminum alloy arc-tooth pulley with flanges, and the smooth pulley 5 can be replaced with a smooth pulley with flanges. The synchronous belt 402 can be an arc-tooth synchronous belt with neoprene rubber on the back and teeth and glass fiber core, or a higher-precision synchronous belt with steel wire core. Other types of tooth shapes, such as trapezoidal, can also be used in actual engineering.

[0045] In the example, the drive shaft 7 acts as a shaft driven by an external torque, simultaneously driving the second bevel gear 2 fixed at the other end to adjust the corresponding valve stem. The drive wheel 4 is fixed to the drive shaft 7, and its rotation drives the driven wheel 3 for adjustment.

[0046] The arc-shaped rack or timing belt can be designed as one or more segments. Figure 6 The design demonstrates a localized transmission mechanism for a circular valve using a synchronous belt, which, in conjunction with an actuator, enables localized adjustment of the valve's opening. Figure 6 Design in Figure 5 Based on this, the length of the synchronous belt is changed so that it forms a loop around the four valve stems, allowing for independent opening adjustment of the four valve stems. In practical engineering, a tensioning mechanism can be added to optimize the direction and wrap angle of the synchronous belt. When using... Figure 5 During the design process, the position of the damper partition plate needs to be adjusted to form an effective closing boundary.

[0047] The gear rack and timing belt design described above can distribute the transmission torque, so that each driven wheel 3 only drives the corresponding valve stem, which is an advantage over the traditional sector valve transmission design. When the transmission ratio of each gear is optimized in the design, the driving force of the working teeth of the driven wheel can be further reduced and the adjustment accuracy can be improved. Figure 5 The driving shaft 7 also serves to drive the gears of the coaxial gear set; it and the driven shaft 6 can be collectively referred to as the drive shaft. Figure 5 The driving wheel in the valve body serves to drive the gears of the coaxial gear set, which, together with the driven wheel, can be referred to as the driving wheel. Furthermore, since the transmission mechanism is located outside the valve body, it is easy to maintain. Gear transmission offers higher transmission accuracy and is more advantageous than other transmission methods. Additionally, the gear set can be standardized during manufacturing, allowing the same model of gear set to be used in valves of different diameters, reducing labor costs in the manufacturing process. All of the above designs also have the advantage of occupying little space.

[0048] In practical applications, the drive pulley can be designed flexibly. For example, its function can be limited to driving the transmission bar, without directly driving the gears in the coaxial gear set. The drive shaft can be designed with a coupling, divided into two parts. The timing belt can be a double-sided toothed timing belt to increase the wrap angle of the timing pulley and reduce the number of tension pulleys; when using a double-sided toothed timing belt, adjacent valve stems can rotate in opposite directions, forming a reversible regulating valve.

[0049] Furthermore, when using synchronous belts, flexible transmission can greatly improve the efficiency of the manufacturing process. In mass valve manufacturing, automated welding and assembly can be adopted. In the manufacturing process, it is only necessary to ensure that the drive shafts are parallel to each other, without having to ensure that all valve stems are located on the same arc. For large-diameter valves, since valve deformation may affect the adjustment accuracy, the transmission mechanism can be flexibly installed on-site to achieve high-precision control. A single gear set, related driven shafts, driven wheels, and related fixed brackets can be prefabricated and fixed to form an installation module. In valve manufacturing, multiple installation modules only need to be positioned by welding or fastening. This simplifies the manufacturing process, increases manufacturing speed, reduces costs, and standardizes the installation modules.

[0050] like Figure 7 As shown in the figure, the installation module is as described above. Figure 5 The design is based on the existing design. The mounting plate in the mounting module is made of 2mm steel plate, and a first axial mounting plate 21 and a second axial mounting plate 22 are added. A radial mounting plate 13 is welded together to form a sturdy mounting module frame. 19 is the output shaft of the mounting module. The lower part of the output shaft 19 is a sliding joint interface with an internal square hole. After the corresponding valve stem 9 is shortened to a suitable length, the upper end is made into a square rod, which can be connected to the sliding joint interface, so that the valve stem is driven by the output shaft. The output shaft passes through the two perforated axial mounting plates, and passes through the thrust bearing 15, the washer 16, and the retaining ring 17 at the top. A sliding bearing or bushing is installed in the middle of the second axial mounting plate 22. A washer and retaining ring 17 are installed at the lower part of the second axial mounting plate where the output shaft passes through. The above design makes the first bevel gear limited by the second axial mounting plate. During operation, the axial thrust generated by it acts on the thrust bearing 15. The driven shaft connected to the second bevel gear adopts the same design. It is limited by a thrust bearing 15, a washer 16, and a retaining ring 17 at the point where it passes through the radial mounting plate 13; and by a sliding bearing 18 at the end. The corresponding parts of the output shaft and the drive shaft are provided with retaining ring grooves.

[0051] The above-mentioned installation module has a reliable design structure and can be mass-produced in a standardized manner. The advantage of the design also lies in the fact that the valve stem is connected by a sliding pair, so that the displacement of the valve stem during operation will not affect the meshing transmission of the bevel gear.

[0052] In some electric and pneumatic drive applications, the stalling of a single valve stem can cause mechanical failure. There are several solutions. For most air valves, the transmission torque is relatively small, and sufficient design margins can be used for the structural strength of a single gear set and the torsional strength of the drive shaft. Additionally, a torque sensor can be added to the drive shaft for added protection. For valves with high torque, a torque sensor can be added to at least one drive shaft. This torque sensor can communicate with the actuator, promptly stopping the external torque input when the drive shaft torque becomes excessive. This design reduces the need for excessive design margins in the driven shaft and gear set, improving economic efficiency.

[0053] For circular valves with parallel stem distribution, the above design is also applicable after the gear set is properly installed and positioned.

[0054] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this application. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A transmission mechanism for a circular valve, comprising a transmission bar, wherein the transmission bar synchronously drives multiple gears to simultaneously rotate multiple valve stems of the circular valve to regulate flow; characterized in that... The transmission mechanism also includes multiple gear sets and multiple parallel axial drive shafts. The gear sets are located outside the valve body and between the drive shafts and the valve stems. The gear sets drive the corresponding valve stems and are driven by the corresponding drive shafts. A drive wheel is fixed on the drive shaft, and the drive wheel meshes with the transmission bar and is synchronously driven by the transmission bar.

2. The transmission mechanism of the circular valve as described in claim 1, characterized in that... The gear set is used to transmit torque and change the direction of torque.

3. The transmission mechanism of the circular valve as described in claim 2, characterized in that... Each of the gear sets contains a pair of bevel gears that mesh with each other to form a 90-degree axial angle.

4. The transmission mechanism of the circular valve as described in claim 1, characterized in that... One of the drive wheels is used for active transmission.

5. The transmission mechanism of the circular valve as described in claim 1, characterized in that... The gear set includes an output shaft, and the output shaft and valve stem are connected by a sliding pair.

6. The transmission mechanism of the circular valve as described in claim 1, characterized in that... The transmission bar is an arc-shaped rack.

7. The transmission mechanism of the circular valve as described in claim 1, characterized in that... The transmission bar is a synchronous belt.

8. The transmission mechanism of the circular valve as described in claim 7, characterized in that... The core wire of the synchronous belt is a steel wire.

9. The transmission mechanism of the circular valve as described in claim 7, characterized in that... The working surface of the synchronous belt is a circular arc tooth.

10. The transmission mechanism of the circular valve as described in claim 1, characterized in that... At least one of the drive shafts is equipped with a torque sensor.

11. The transmission mechanism of the circular valve as described in claim 1, characterized in that... The transmission mechanism includes at least one mounting module; the mounting module includes the gear set, related fixing brackets, and is pre-manufactured.

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