Flat gate valve with anti-blocking trapezoidal thread lubricating structure

Abstract

The present application discloses a flat gate valve with anti-blocking trapezoidal thread lubricating structure, comprising a valve body, a valve seat, a valve rod, a gate, a valve rod nut and a hand wheel, the gate is located in the valve body, the valve seat is located in the valve body, the valve rod nut is arranged on the top of the valve seat, the top of the valve rod penetrates through the valve rod nut and is threadedly connected with the valve rod nut, the hand wheel is connected with the valve rod nut, the outer part of the valve rod nut is sleeved with a fixing piece, the fixing piece is provided with an oil injection nozzle and a first through hole, the oil injection nozzle is assembled in the first through hole, and the oil injection nozzle can inject lubricating medium to the threaded connection part of the valve rod and the valve rod nut through the first through hole. After the flat gate valve is used for a period of time, only the lubricating medium needs to be injected to the threaded engagement part of the valve rod and the valve rod nut through the oil injection nozzle, so that the smoothness between the valve rod and the valve rod nut can be ensured, and the situation that the hand wheel is not sensitive to rotation can be avoided.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and more specifically, to a flat gate valve with an anti-jamming trapezoidal thread lubrication structure. Background Technology

[0002] Gate valves, as a commonly used type of shut-off valve, allow for unobstructed flow of the medium and minimize pressure loss when fully open. They are typically suitable for applications where frequent opening and closing is not required and the valve needs to remain fully open or closed. The opening and closing of a gate valve is achieved through the threaded engagement of the valve stem and valve stem nut. Turning the handwheel rotates the valve stem nut, which in turn drives the valve stem to move the gate up and down, thus opening and closing the valve.

[0003] In practical use, the problem of handwheel rotation being insensitive often occurs. The main reason is that maintaining a fully open or fully closed state for a long time leads to poor lubrication of the trapezoidal thread of the valve stem nut, especially in gate valves with exposed valve stems. The valve stem nut of traditional gate valves is usually installed inside the support box, and its surface lubrication is easily neglected during routine maintenance. Maintaining one operating condition for a long time causes the trapezoidal thread to lack lubrication, resulting in increased operating resistance and difficulty in handwheel rotation.

[0004] Common repair methods for this problem are as follows: 1. Disassemble the handwheel, bracket, and valve stem nut in sequence; 2. Thoroughly clean the trapezoidal threaded area of ​​the valve stem and valve stem nut; 3. Apply special grease evenly to the thread surface; 4. Reinstall all components to restore the structural integrity.

[0005] As can be seen from the above maintenance steps, once maintenance is required, not only is it necessary to shut off the water supply, but also to completely disassemble and reassemble the gate valve. The process is complicated. How to maintain lubrication between the valve stem and the valve stem nut while the gate valve is maintained under a certain working condition for a long time is the technical problem that this application aims to solve. Summary of the Invention

[0006] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. The summary section of this invention is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0007] To at least partially solve the above problems, the present invention provides a flat gate valve with an anti-jamming trapezoidal thread lubrication structure, comprising: a valve body, a valve seat, a valve stem, a gate, a valve stem nut, and a handwheel. The gate is located within the valve body and disposed at the bottom of the valve stem. The valve seat is located within the valve body and disposed on both sides of the gate. The valve stem nut is disposed at the top of the valve seat. The top of the valve stem passes through the valve stem nut and is threadedly connected to the valve stem nut. The handwheel is connected to the valve stem nut. A fixing member is sleeved on the outside of the valve stem nut. The fixing member is provided with an oil injection nozzle and a first through hole. The oil injection nozzle is assembled in the first through hole, and the oil injection nozzle can inject lubricating medium into the threaded connection between the valve stem and the valve stem nut through the first through hole.

[0008] Preferably, the valve seat is provided with a bracket, the bracket is provided with a second through hole for accommodating the valve stem, the second through hole and the valve stem are located on the same central axis, the bottom of the bracket is connected to the valve body, the fixing member is provided at the top of the bracket, the valve stem passes through the valve body through the bracket and the fixing member, and the valve stem nut is provided on the bracket.

[0009] Preferably, the valve stem nut is provided with a planar thrust bearing, and the valve stem nut is connected to the bracket and / or the fixing member through the planar thrust bearing.

[0010] Preferably, the number of planar thrust bearings is two.

[0011] Preferably, the top of the bracket is provided with a mounting groove, the valve stem nut is located in the mounting groove, the outer wall of the valve stem nut is provided with a limiting ring, two planar thrust bearings are respectively located on the upper and lower sides of the limiting ring, the lower planar thrust bearing is connected to the bottom of the mounting groove, the fixing member is located at the opening of the mounting groove, the upper planar thrust bearing is connected to the bottom of the fixing member, and the fixing member is movably connected to the valve stem nut.

[0012] Preferably, the valve stem nut has a lubricating oil groove located between the external thread of the valve stem and the internal thread of the valve stem nut.

[0013] Preferably, the inner wall surface of the internal thread of the valve stem nut is tapered.

[0014] Preferably, the inner wall surface of the valve stem nut has a second distance between the uppermost inner wall surface and the outer wall surface of the valve stem's outer thread, and the inner wall surface of the lowermost inner wall surface has a third distance between the outer wall surface of the valve stem's outer thread.

[0015] Preferably, the second distance is greater than the third distance.

[0016] Preferably, the third distance is greater than zero.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: With the above structural design, after a period of use, the flat gate valve only needs to inject lubricating medium into the threaded engagement of the valve stem and valve stem nut through the oil injection nozzle to ensure smooth operation between the valve stem and valve stem nut and avoid the situation where the handwheel is not rotating smoothly.

[0018] The flat gate valve with an anti-jamming trapezoidal thread lubrication structure described in this invention, other advantages, objectives and features of this invention will be partly apparent from the following description, and partly understood by those skilled in the art through study and practice of this invention. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the left view of the flat gate valve with an anti-jamming trapezoidal thread lubrication structure according to the present invention.

[0020] Figure 2 This is a schematic diagram of the front view of the flat gate valve with an anti-jamming trapezoidal thread lubrication structure according to the present invention.

[0021] Figure 3 This is a schematic diagram of a second embodiment of the fastener.

[0022] Figure 4 for Figure 3 A schematic diagram of the external thread of the valve stem and the internal thread of the valve stem nut.

[0023] Figure 5 This is a schematic diagram showing the angle between the inner wall of the valve stem nut's internal thread and the vertical direction.

[0024] Figure 6 This is a diagram comparing the second and third distances.

[0025] In the figure: 1 Valve body, 2 Valve seat, 3 Valve stem, 4 Gate, 5 Valve stem nut, 51 Limiting ring, 6 Handwheel, 7 Fixing component, 71 First through hole, 8 Oil nozzle, 9 Bracket, 91 Second through hole, 92 Mounting groove, 10 Planar thrust bearing. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, so that those skilled in the art can implement it based on the description.

[0027] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0028] like Figures 1-6 As shown, the present invention provides a flat gate valve with an anti-jamming trapezoidal thread lubrication structure, comprising: a valve body 1, a valve seat 2, a valve stem 3, a gate 4, a valve stem nut 5, and a handwheel 6. The gate 4 is located inside the valve body 1 and is disposed at the bottom of the valve stem 3. The valve seat 2 is located inside the valve body 1 and is disposed on both sides of the gate 4. The valve stem nut 5 is disposed at the top of the valve seat 2. The top of the valve stem 3 passes through the valve stem nut 5 and is threadedly connected to the valve stem nut 5. The handwheel 6 is connected to the valve stem nut 5. The valve body 1, valve seat 2, valve stem 3, gate 4, and handwheel 6 are all commercially available products or existing technologies. The difference from existing technologies is that the valve stem nut 5 is externally fitted with a fixing member 7, which is used to fix the valve stem nut 5. The fixing member 7 is provided with an oil injection nozzle 8 and a first through hole 71. The oil injection nozzle 8 is assembled in the first through hole 71. The oil injection nozzle 8 can inject lubricating medium into the threaded connection between the valve stem 3 and the valve stem nut 5 through the first through hole 71. The lubricating medium can be liquid lubricating oil or solid grease.

[0029] Normally, the opening of the first through hole 71 inside the fixing member 7 is located at the top of the valve stem nut 5, and the lubricating medium can lubricate the threads between the valve stem 3 and the valve stem nut 5 during the up and down movement of the valve stem.

[0030] With the above structural design, after the flat gate valve has been used for a period of time, it is only necessary to inject lubricating medium into the threaded engagement of the valve stem 3 and the valve stem nut 5 through the oil injection nozzle 8 to ensure smooth operation between the valve stem 3 and the valve stem nut 5 and avoid the situation where the handwheel 6 is not rotating smoothly.

[0031] Furthermore, a bracket 9 is provided on the valve seat 2, and the bracket 9 has a second through hole 91 for accommodating the valve stem 3. The second through hole 91 and the valve stem 3 are located on the same central axis. The bottom of the bracket 9 is connected to the valve body 1, and the fixing member 7 is provided on the top of the bracket 9. Figures 1-3 As shown, the valve stem 3 passes through the valve body 1, the bracket 9, and the fixing member 7, and the valve stem nut 5 is disposed on the bracket 9.

[0032] A planar thrust bearing 10 is provided on the valve stem nut 5, and the valve stem nut 5 is connected to the bracket 9 and / or the fixing member 7 through the planar thrust bearing 10.

[0033] Preferably, the number of planar thrust bearings 10 is two.

[0034] by Figure 1 and Figure 2 The gate valve shown is a first embodiment. In this embodiment, the rotation axis of the handwheel 6 is perpendicular to the rotation axis of the valve stem nut 5, and the handwheel 6 and the valve stem nut 5 are connected by a bevel gear set for transmission. Figure 1 As shown, a first bevel gear is installed on the rotating shaft of the handwheel 6, and a second bevel gear is installed on the outer wall of the valve stem nut 5. Both the first and second bevel gears are located inside the fixing member 7, and the first bevel gear meshes with the second bevel gear. The rotating shaft of the handwheel 6 is assembled onto the fixing member 7 via bearings and other structures. Two planar thrust bearings 10 are located, one below the limiting retaining ring 51 of the valve stem nut 5, and the other at the top of the valve stem nut 5. Figure 1 and Figure 2 As shown, the valve stem nut 5 is assembled in the fixing part 7 by two planar thrust bearings 10, so that the valve stem nut 5 can rotate, while its position can be limited in the axial direction to prevent it from moving with the valve stem 3.

[0035] In this embodiment, since the rotation axis of the handwheel 6 is perpendicular to the rotation axis of the valve stem nut 5, the fixing member 7 can be used as a fixing device for the handwheel 6 and the valve stem nut 5.

[0036] In the first embodiment, the rotation axis of the handwheel 6 is perpendicular to the rotation axis of the valve stem nut 5. In this embodiment, we use the alignment of the rotation axis of the handwheel 6 and the rotation axis of the valve stem nut 5 as the second embodiment. Figure 3 As shown, Figure 3 Only a portion of the structure of the valve stem 3, a portion of the structure of the bracket 9, the valve stem nut 5, the two planar thrust bearings 10, and the fixing component 7 are shown.

[0037] In this embodiment, the top of the bracket 9 is provided with a mounting groove 92, and the opening of the second through hole 91 is located on the inner bottom surface of the mounting groove 92, such as... Figure 3 As shown, the valve stem nut 5 is located in the mounting groove 92. A limiting ring 51 is provided on the outer wall of the valve stem nut 5. Two planar thrust bearings 10 are located on the upper and lower sides of the limiting ring 51, respectively. The lower planar thrust bearing 10 is connected to the bottom of the mounting groove 92. The fixing member 7 has a T-shaped cross-section and is located at the opening of the mounting groove 92. The top of the fixing member 7 is secured to the top of the bracket 9 and covers the opening of the mounting groove. The bottom of the fixing member 7 is inserted into the mounting groove. The upper planar thrust bearing 10 is connected to the bottom of the fixing member 7. The fixing member 7 encapsulates the valve stem nut 5 within the mounting groove. The top of the valve stem nut penetrates the fixing member 7 and extends to the outside of the fixing member 7. The fixing member 7 is movably connected to the valve stem nut 5, allowing the valve stem nut 5 to rotate relative to the fixing member 7. A handwheel 6 is fitted on the portion of the valve stem nut 5 extending to the outside of the fixing member 7. Figure 3(Not shown in the image), the handwheel 6 can also be directly mounted on top of the valve stem 3.

[0038] In the aforementioned embodiments, we mentioned that lubricating medium can be injected into the threaded connection between the valve stem 3 and the valve stem nut 5 through the grease nipple 8 to prevent jamming when rotating the handwheel 6. However, in actual applications, the injected lubricating medium can only accumulate near the first through hole. Once the valve stem 3 and the valve stem nut 5 rust, a long waiting time is required for the lubricating medium to penetrate them. To improve the lubrication effect of the lubricating medium, we have further optimized the design of the valve stem nut 5.

[0039] In this embodiment, the valve stem nut 5 has a lubricating oil groove located between the external thread of the valve stem 3 and the internal thread of the valve stem nut 5. The inner wall of the internal thread of the valve stem nut 5 is tapered, wider at the top and narrower at the bottom. The inner diameter R of the uppermost internal thread (i.e., the inner diameter of the inner wall at the uppermost end of the internal thread) is larger than the inner diameter r of the lowermost internal thread (i.e., the inner diameter of the inner wall at the lowermost end of the internal thread). The inner wall has an angle α with the vertical direction. Figure 5 As shown, preferably, the included angle α is no greater than 3°.

[0040] In order to accommodate the tapered design with a larger diameter at the bottom and a smaller diameter at the top of the inner wall, and without affecting the rotation of the valve stem 3, the inner diameter r of the inner wall surface of the lowest internal thread should not be less than the outer diameter of the external thread of the valve stem 3.

[0041] Furthermore, the inner wall surface of the valve stem nut 5, located at its uppermost point, has a second distance from the outer wall surface of the valve stem 3's outer thread, and the inner wall surface located at its lowermost point has a third distance from the outer wall surface of the valve stem 3's outer thread, as shown below. Figure 6 As shown.

[0042] Furthermore, the second distance is greater than the third distance.

[0043] Preferably, the third distance is greater than zero, thereby avoiding blind spots that the lubricating medium cannot cover.

[0044] Through the above structural design, a lubricating oil groove is formed between the outer wall of the external thread of the valve stem 3 and the inner wall of the internal thread of the valve stem nut 5, and the flow area of ​​the lubricating oil groove gradually decreases from top to bottom. Figure 4 and Figure 6As shown, because of the pre-reserved lubricating oil groove, when the high-pressure lubricating medium is injected into the grease nipple 8, the lubricating medium can spread throughout the lubricating oil groove, thereby enabling the lubricating medium to effectively penetrate into the mating surface of the external thread of the valve stem 3 and the internal thread of the valve stem nut 5. This prevents the lubricating medium from concentrating near the first through hole and failing to penetrate into the bottom of the valve stem nut 5. At the same time, by setting the lubricating oil groove, the lubricating medium can be stored, ensuring that there is always lubricating medium between the valve stem 3 and the valve stem nut 5, thus preventing the valve stem 3 from running out of oil due to maintaining the same working condition for a long time.

[0045] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0046] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. Other modifications can be easily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A flat gate valve with an anti-jamming trapezoidal thread lubrication structure, including: The valve body (1), valve seat (2), valve stem (3), gate (4), valve stem nut (5), and handwheel (6) are provided. The gate (4) is located inside the valve body (1) and is disposed at the bottom of the valve stem (3). The valve seat (2) is located inside the valve body (1) and is disposed on both sides of the gate (4). The valve stem nut (5) is disposed at the top of the valve seat (2). The top of the valve stem (3) passes through the valve stem nut (5) and is threadedly connected to the valve stem nut (5). The handwheel (6) is connected to the valve stem nut (5). The valve stem nut (5) is characterized in that a fixing member (7) is sleeved on the outside of the valve stem nut (5). The fixing member (7) is provided with an oil injection nozzle (8) and a first through hole (71). The oil injection nozzle (8) is assembled in the first through hole (71). The oil injection nozzle (8) can inject lubricating medium into the threaded connection between the valve stem (3) and the valve stem nut (5) through the first through hole (71). The valve seat (2) is provided with a bracket (9), and the bracket (9) is provided with a second through hole (91) for accommodating the valve stem (3). The second through hole (91) and the valve stem (3) are located on the same central axis. The bottom of the bracket (9) is connected to the valve body (1). The fixing member (7) is provided on the top of the bracket (9). The valve stem (3) passes through the valve body (1) through the bracket (9) and the fixing member (7). The valve stem nut (5) is provided on the bracket (9). A planar thrust bearing (10) is provided on the valve stem nut (5), and the valve stem nut (5) is connected to the bracket (9) and / or the fixing member (7) through the planar thrust bearing (10). The bracket (9) has a mounting groove (92) at its top. The valve stem nut (5) is located in the mounting groove (92). The outer wall of the valve stem nut (5) is provided with a limiting ring (51). Two planar thrust bearings (10) are located on the upper and lower sides of the limiting ring (51), respectively. The lower planar thrust bearing (10) is connected to the bottom of the mounting groove (92). The fixing member (7) is located at the opening of the mounting groove (92). The upper planar thrust bearing (10) is connected to the bottom of the fixing member (7). The fixing member (7) is movably connected to the valve stem nut (5).

2. The flat gate valve with an anti-jamming trapezoidal thread lubrication structure according to claim 1, characterized in that, The number of planar thrust bearings (10) is two.

3. The flat gate valve with an anti-jamming trapezoidal thread lubrication structure according to claim 1, characterized in that, The valve stem nut (5) has a lubricating oil groove located between the external thread of the valve stem (3) and the internal thread of the valve stem nut (5).

4. The flat gate valve with an anti-jamming trapezoidal thread lubrication structure according to claim 3, characterized in that, The inner wall of the internal thread of the valve stem nut (5) is tapered.

5. The flat gate valve with an anti-jamming trapezoidal thread lubrication structure according to claim 4, characterized in that, The inner thread of the valve stem nut (5) has a second distance between the uppermost inner wall surface and the outer wall surface of the outer thread of the valve stem (3), and the lowermost inner wall surface has a third distance between the outer wall surface of the outer thread of the valve stem (3).

6. The flat gate valve with an anti-jamming trapezoidal thread lubrication structure according to claim 5, characterized in that, The second distance is greater than the third distance.

7. The flat gate valve with an anti-jamming trapezoidal thread lubrication structure according to claim 5, characterized in that, The third distance is greater than zero.

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