Shaft sleeve and valve rod connecting shaft assembling structure of large-diameter butterfly valve

Abstract

The utility model relates to the technical field of butterfly valves, in particular to a shaft sleeve and valve rod connecting shaft assembling structure of a large-diameter butterfly valve, which adopts the technical scheme that the shaft sleeve and valve rod connecting shaft assembling structure comprises a valve body, a first mounting seat and a second mounting seat are mounted on the valve body, a butterfly plate is mounted on the valve body through a valve rod body, and the butterfly plate is detachably connected with the valve rod body through a positioning pin; a first communicating groove is formed in the first mounting base, a second step groove is formed in the first communicating groove, the cross section of the second step groove is of a rectangular structure, a first shaft sleeve is embedded in the second step groove, and the second step groove limits rotation of the first shaft sleeve; and a second communicating groove is formed in the second mounting base, a third step groove is formed in the second communicating groove, the cross section of the third step groove is of a rectangular structure, a second shaft sleeve is embedded in the third step groove, and the third step groove limits rotation of the second shaft sleeve. The utility model has the advantages that the shaft sleeve is assembled without rotation in the circumferential direction, the micrometric displacement is resisted and the stability is enhanced.

Description

Technical Field

[0001] The utility model relates to the technical field of butterfly valves, in particular to a shaft sleeve and valve stem coupling assembly structure of a large-caliber butterfly valve. Background Art

[0002] Butterfly valves, as key devices in the fluid control field, are widely used in municipal water supply and drainage, power systems, and industrial pipelines. They open and close pipelines by rotating the disc through the valve stem. Large-diameter butterfly valves, due to their large diameter and high pressure requirements, require the stem system to withstand greater torque and radial loads. Traditional structures typically feature mounting blocks on both sides of the valve body, with sleeves supporting the stem and transmitting the driving force.

[0003] In this type of design, the sleeve must ensure smooth rotation of the valve stem while also possessing excellent wear resistance and sealing properties, while also considering assembly stability and long-term operational reliability. However, the sleeve of existing large-diameter butterfly valves is prone to circumferential rotation or micro-displacement within the mounting groove, causing the valve stem's rotation center to shift and exacerbating eccentric wear on the sealing surface between the butterfly plate and the valve body. Furthermore, sleeve rotation causes the seal ring to rotate with it, leading to localized extrusion failure. Under alternating loads, assembly clearances are easily created due to micro-wear, which not only reduces transmission accuracy but also causes connectors to loosen due to vibration, significantly increasing maintenance frequency and the risk of failure.

[0004] Therefore, a shaft sleeve and valve stem coupling assembly structure of a large-diameter butterfly valve is proposed to solve the above problems. Utility Model Content

[0005] The purpose of the utility model is to provide a shaft sleeve and valve stem coupling assembly structure for a large-caliber butterfly valve, which has the advantages of circumferential non-rotational assembly of the shaft sleeve, resistance to micro-displacement and enhanced stability, and solves the problem of increased micro-wear and decreased transmission accuracy caused by circumferential rotation or micro-displacement of the existing shaft sleeve in the installation groove.

[0006] To achieve the above-mentioned object, the present invention provides the following technical solution: a shaft sleeve and valve stem coupling assembly structure for a large-caliber butterfly valve, comprising a valve body, a first mounting seat and a second mounting seat mounted on the valve body, a butterfly plate mounted on the valve body through a valve stem body, the butterfly plate being detachably connected to the valve stem body via a locating pin, a first communicating groove being defined in the first mounting seat, a second step groove being defined in the first communicating groove, the second step groove having a rectangular cross-section and embedded with a first shaft sleeve, the second step groove limiting the rotation of the first shaft sleeve;

[0007] A second connecting groove is formed in the second mounting seat, and a third step groove is formed in the second connecting groove. The third step groove has a rectangular cross section and is embedded with the second shaft sleeve. The third step groove limits the rotation of the second shaft sleeve.

[0008] The first shaft sleeve and the second shaft sleeve are both rotatably connected to the valve stem body.

[0009] Preferably, a connecting seat is provided on the valve body, and a hole for installing bolts is opened on the connecting seat.

[0010] In the design, the connecting seat realizes the rapid connection between the valve body and the external pipe flange by opening bolt installation holes. Its standardized interface design has high compatibility, and the use of multiple bolts evenly distributed circumferentially ensures the vibration stability of the valve body under high-pressure conditions.

[0011] Preferably, a fastening bolt is provided on the first mounting seat, a top cover is mounted on the first mounting seat via the fastening bolt, the fastening bolt passes through the top cover and is threadedly connected with a fastening nut, and a through hole is provided on the upper end surface of the top cover.

[0012] In the design, the top cover realizes the removable seal on the top of the first mounting seat through the locking cooperation of the fastening bolts and the fastening nuts. Its through-hole structure adopts a design that can be penetrated by the valve stem body, and has dynamic sealing compensation capability; the rigid clamping structure of the top cover further limits the axial displacement of the first sleeve to prevent micro-wear.

[0013] Preferably, a first step groove is opened in the first connecting groove above the second step groove, and the cross-section of the first step groove is an irregular shape; a gasket, a positioning ring and a first sealing ring are installed in the first step groove from top to bottom, and the gasket, positioning ring and first sealing ring are all rotatably connected to the valve stem body and are circumferentially limited by the first step groove.

[0014] In the design, the gasket, positioning ring and first sealing ring realize the layered sealing function through the stepped limit of the first step groove: the gasket adopts wear-resistant material to bear the axial load, the irregular cross-section of the positioning ring prevents circumferential rotation, and the elastic structure of the first sealing ring compensates for the thermal expansion of the valve stem body; the three work together to have anti-eccentric wear and self-aligning capabilities, significantly reducing the risk of sealing failure.

[0015] Preferably, a bottom cover is detachably mounted on the bottom of the second mounting seat by means of bolts, and a top block for tightening the second sleeve is provided on the bottom cover, and the top block and the bottom cover are integrally formed.

[0016] In the design, the bottom cover and the top block achieve axial fixation of the second sleeve through the pre-tightening force of the bolts, and the end face clamping structure of the top block can tighten the second sleeve; the detachable installation of the bottom cover facilitates the quick replacement of the second sealing ring during maintenance, reducing downtime.

[0017] Preferably, a fourth step groove is provided in the second communicating groove below the third step groove, and a second sealing ring is embedded in the fourth step groove.

[0018] In the design, the second sealing ring is embedded in the fourth step groove to achieve static sealing; the structure adopts a double-lip design with two-way blocking capability, wherein the upper lip prevents medium leakage, and the lower lip blocks external impurities from invading the valve stem rotating pair, thereby extending the bearing life.

[0019] Preferably, the valve stem body passes through the first communicating groove and the second communicating groove, and a shaft shoulder is provided on the top of the valve stem body. The shaft shoulder passes through the hole on the top cover and is integrally formed with a connecting key.

[0020] In the design, the one-piece structure of the shaft shoulder and the connecting key enhances the transmission rigidity of the valve stem body: the shaft shoulder is axially positioned through the through hole in the top cover, and the rectangular spline of the connecting key is designed to transmit the driving torque; the whole is forged with high-strength alloy, which has the ability to resist torsional deformation and prevent the butterfly plate from deflecting due to torque distortion.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] The utility model embeds a first shaft sleeve and a second shaft sleeve with a rectangular cross section into the second step groove of the first mounting seat and the third step groove of the second mounting seat respectively, and realizes circumferential zero rotation assembly of the shaft sleeves by utilizing the rigid constraint of the rectangular structure, thereby fundamentally eliminating micro-displacement of the shaft sleeves in the mounting grooves;

[0023] At the same time, the first and second sleeves form a rotating pair only with the valve stem body, ensuring the stability of the valve stem body's rotation center. This structure effectively solves the problems of increased micro-wear, reduced transmission accuracy, and uneven wear of the butterfly disc caused by rotation or micro-displacement of traditional sleeves, significantly improving the reliability and service life of large-diameter butterfly valves. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the main structure of the utility model;

[0025] Figure 2 This is another perspective structural diagram of the present invention;

[0026] Figure 3 This is a schematic diagram of the valve body connection structure of the utility model;

[0027] Figure 4 This is a schematic diagram of the cross-sectional connection structure of the valve body of the present utility model;

[0028] Figure 5 This is a schematic diagram of the cross-sectional structure of the valve body of the present utility model;

[0029] Figure 6 This is a schematic structural diagram of the valve stem body of the present utility model.

[0030] In the figure: 1. valve body; 11. connecting seat; 12. first mounting seat; 120. first communicating groove; 121. fastening bolt; 122. gasket; 123. positioning ring; 124. first sealing ring; 125. first step groove; 126. second step groove; 13. second mounting seat; 130. second communicating groove; 131. second sealing ring; 132. third step groove; 133. fourth step groove; 2. top cover; 21. fastening nut; 3. valve stem body; 31. shaft shoulder; 32. connecting key; 4. butterfly plate; 41. positioning pin; 5. bottom cover; 51. top block; 6. first shaft sleeve; 7. second shaft sleeve. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] Example 1: Figures 1 to 6 As shown, an embodiment of the present invention provides: a shaft sleeve and valve stem coupling assembly structure of a large-caliber butterfly valve, including a valve body 1, a first mounting seat 12 and a second mounting seat 13 are installed on the valve body 1, a butterfly plate 4 is installed on the valve body 1 through a valve stem body 3, and the butterfly plate 4 is detachably connected to the valve stem body 3 through a positioning pin 41, a first connecting groove 120 is defined in the first mounting seat 12, a second step groove 126 is defined in the first connecting groove 120, the second step groove 126 has a rectangular cross-section and is embedded with a first shaft sleeve 6, and the second step groove 126 limits the rotation of the first shaft sleeve 6;

[0033] A second connecting groove 130 is defined in the second mounting seat 13. A third step groove 132 is defined in the second connecting groove 130. The third step groove 132 has a rectangular cross section and is embedded with the second shaft sleeve 7. The third step groove 132 limits the rotation of the second shaft sleeve 7.

[0034] The first shaft sleeve 6 and the second shaft sleeve 7 are both rotatably connected to the valve stem body 3 .

[0035] Specifically, by respectively embedding the first shaft sleeve 6 and the second shaft sleeve 7 with rectangular cross-sections into the second step groove 126 of the first mounting seat 12 and the third step groove 132 of the second mounting seat 13, the circumferential zero rotation assembly of the shaft sleeves is achieved by utilizing the rigid constraint of the rectangular structure, thereby fundamentally eliminating the micro-displacement of the shaft sleeves in the mounting grooves;

[0036] At the same time, the first and second sleeves 6 and 7 form only a revolving pair with the valve stem body 3, ensuring the stability of the valve stem body 3's rotation center. This structure effectively solves the problems of increased micro-wear, decreased transmission accuracy, and eccentric wear of the butterfly disc 4 caused by rotation or micro-displacement of traditional sleeves, significantly improving the reliability and service life of large-diameter butterfly valves.

[0037] Example 2: Figure 3 、 Figure 4 and Figure 6 As shown, in this embodiment, a connecting seat 11 is integrally formed on the valve body 1. The connecting seat 11 is evenly provided with holes for installing bolts along the circumference of the valve body 1 to ensure uniform force when the valve body is connected to the pipeline flange and to prevent loosening of the connection under high-pressure conditions; fastening bolts 121 are circumferentially arranged on the top of the first mounting seat 12, and a rubber sealing gasket is sandwiched between the first mounting seat 12 and the top cover 2. After the fastening bolts 121 pass through the corresponding through holes on the top cover 2, they are threadedly connected with the fastening nuts 21 and pre-tightened, and static sealing between the top cover 2 and the first mounting seat 12 is achieved through the elastic deformation of the sealing gasket;

[0038] A first step groove 125 with an irregular cross section is provided in the first communicating groove 120 above the second step groove 126. A washer 122 made of polytetrafluoroethylene, a positioning ring 123 made of stainless steel, and a first sealing ring 124 made of nitrile rubber are installed in sequence from top to bottom in the first step groove 125. The washer 122 is used to bear the axial load of the valve stem body 3 to prevent the positioning ring 123 from being squeezed and deformed. The outer wall of the positioning ring 123 has a shape that matches the first step groove 125 and adopts an interference fit, which completely limits the circumferential rotation of the positioning ring 123. The first sealing ring 124 matches the cross-sectional size of the positioning ring 123. The washer 122, the positioning ring 123 and the first sealing ring 124 are all rotatably connected to the valve stem body 3, allowing the valve stem body 3 to rotate smoothly, and circumferential limitation is achieved by the shape of the first step groove 125.

[0039] The valve stem body 3 passes through the first connecting groove 120 and the second connecting groove 130, and a shaft shoulder 31 is integrally formed on the top. When the valve stem body 3 is installed in place, the shaft shoulder 31 abuts against the upper end surface of the top cover 2 to achieve axial positioning of the valve stem body 3; a connecting key 32 with a rectangular spline structure is integrally formed on the top of the shaft shoulder 31, which is used to transmit driving torque and avoid circumferential sliding between the valve stem body 3 and the driving device.

[0040] Example 3: Figure 2 and Figure 5As shown, in this embodiment, a bottom cover 5 is detachably mounted on the bottom of the second mounting seat 13 by bolts. A cylindrical top block 51 is integrally formed on the bottom cover 5. When the bottom cover 5 is installed in place, the upper end surface of the top block 51 is completely in contact with the bottom end surface of the second shaft sleeve 7. The axial tightening of the second shaft sleeve 7 is achieved by the pre-tightening force of the bolts to prevent axial displacement of the second shaft sleeve 7 when the valve stem body 3 rotates. An asbestos sealing gasket is sandwiched between the bottom cover 5 and the second mounting seat 13 to achieve static sealing between the bottom cover 5 and the second mounting seat 13.

[0041] The third step groove 132 is a rectangular structure whose cross section matches the outer wall of the second sleeve 7. The second sleeve 7 is embedded in the third step groove 132. The circumferential rotation of the second sleeve 7 is limited by the cooperation of the rectangular structure.

[0042] A fourth step groove 133 is provided in the second connecting groove 130 below the third step groove 132. A second sealing ring 131 made of fluororubber is embedded in the fourth step groove 133. The second sealing ring 131 is a double-lip sealing ring. The upper lip fits tightly against the outer wall of the second shaft sleeve 7, and the lower lip fits against the bottom of the fourth step groove 133 to achieve bidirectional sealing. The upper lip prevents the pipeline medium from leaking along the gap between the second shaft sleeve 7 and the second connecting groove 130, and the lower lip blocks external air, moisture and impurities from invading the valve stem rotating pair, thereby extending the service life of the second shaft sleeve 7.

[0043] When the present invention is used, the first sleeve 6 is inserted into the second stepped groove 126 of the first mounting seat 12, where its circumferential rotation is restricted by its rectangular cross-section. Simultaneously, the second sleeve 7 is inserted into the third stepped groove 132 of the second mounting seat 13, also providing rotational restraint. The first sealing ring 124, the positioning ring 123, and the washer 122 are then sequentially installed into the first stepped groove 125. These three elements fit over the outer ring of the valve stem body 3, and their irregular profiles restrict circumferential deflection. Simultaneously, the second sealing ring 131, with its double-lip design, is inserted into the fourth stepped groove 133 to achieve a static seal.

[0044] Pre-connect the butterfly plate 4 to the valve stem body 3 via the locating pin 41 to maintain fine-tuning alignment. Then, insert the valve stem body 3 through the first and second connecting grooves 120 and 130 to form a revolving pair. After adjusting the butterfly plate 4 to the center of the valve body 1 cavity, lock the locating pin 41 to achieve a rigid connection. Use the top block 51 of the bottom cover 5 to press against the bottom of the second sleeve 7 and tighten with bolts. Simultaneously, install the top cover 2 and tighten the seal assembly with the fastening bolts 121 and fastening nuts 21.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed within the present invention. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A shaft sleeve and valve stem coupling assembly structure for a large-caliber butterfly valve, comprising a valve body (1), a first mounting seat (12) and a second mounting seat (13) being mounted on the valve body (1), a butterfly plate (4) being mounted on the valve body (1) via a valve stem body (3), the butterfly plate (4) being detachably connected to the valve stem body (3) via a locating pin (41), and characterized in that: A first connecting groove (120) is provided in the first mounting seat (12), a second step groove (126) is provided in the first connecting groove (120), the second step groove (126) has a rectangular cross-section and is embedded with the first shaft sleeve (6), and the second step groove (126) limits the rotation of the first shaft sleeve (6); A second connecting groove (130) is provided in the second mounting seat (13), a third step groove (132) is provided in the second connecting groove (130), the third step groove (132) has a rectangular cross-section and is embedded with a second shaft sleeve (7), and the third step groove (132) limits the rotation of the second shaft sleeve (7); The first shaft sleeve (6) and the second shaft sleeve (7) are both rotatably connected to the valve stem body (3).

2. The shaft sleeve and valve stem coupling assembly structure of a large-caliber butterfly valve according to claim 1 is characterized in that: A connecting seat (11) is provided on the valve body (1), and a hole for installing a bolt is opened on the connecting seat (11).

3. The shaft sleeve and valve stem coupling assembly structure of a large-caliber butterfly valve according to claim 1 is characterized in that: A fastening bolt (121) is provided on the first mounting seat (12), and a top cover (2) is mounted on the first mounting seat (12) via the fastening bolt (121). The fastening bolt (121) passes through the top cover (2) and is threadedly connected to a fastening nut (21). A through hole is provided on the upper end surface of the top cover (2).

4. The shaft sleeve and valve stem coupling assembly structure of a large-caliber butterfly valve according to claim 1 is characterized in that: A first step groove (125) is provided in the first connecting groove (120) above the second step groove (126), and the cross section of the first step groove (125) is irregular in shape; a gasket (122), a positioning ring (123) and a first sealing ring (124) are installed in the first step groove (125) from top to bottom, and the gasket (122), the positioning ring (123) and the first sealing ring (124) are all rotatably connected to the valve stem body (3) and are circumferentially limited by the first step groove (125).

5. The shaft sleeve and valve stem coupling assembly structure of a large-caliber butterfly valve according to claim 1 is characterized in that: A bottom cover (5) is detachably mounted on the bottom of the second mounting seat (13) via bolts. The bottom cover (5) is provided with a top block (51) for tightening the second shaft sleeve (7). The top block (51) and the bottom cover (5) are integrally formed.

6. The shaft sleeve and valve stem coupling assembly structure of a large-caliber butterfly valve according to claim 1, characterized in that: A fourth step groove (133) is provided in the second connecting groove (130) below the third step groove (132), and a second sealing ring (131) is embedded and installed in the fourth step groove (133).

7. The shaft sleeve and valve stem coupling assembly structure of a large-caliber butterfly valve according to claim 1, characterized in that: The valve stem body (3) passes through the first connecting groove (120) and the second connecting groove (130), and a shaft shoulder (31) is provided on the top of the valve stem body (3). The shaft shoulder (31) passes through the hole on the top cover (2) and is integrally formed with a connecting key (32).

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