Valve rod fixing device

Abstract

The utility model discloses a valve rod fixing device, and relates to the field of valves. The two supports are oppositely arranged, one ends of the two supports are fixedly connected to the side wall of the valve body, and the other ends of the two supports jointly form an annular bearing cavity coaxial with the valve rod. One end of the connecting shaft extends into the annular bearing cavity and is in rigid axial constraint connection with the top of the valve rod; an axial bearing is arranged between the inner side wall of the annular bearing cavity and the outer side wall of the connecting shaft, and the axial end face of the axial bearing abuts against the corresponding support and the axial bearing face of the connecting shaft. The sealing cover assembly is installed at the axial opening of the annular bearing cavity, and a sealing cavity is formed by the sealing cover assembly, the outer wall of the connecting shaft and the side wall of the annular bearing cavity. The axial bearing is located in the sealed chamber. The connecting shaft and the valve rod form rigid axial constraint connection, so that the valve rod and the connecting shaft are tightly attached without relative displacement, the axial acting force generated by a medium under the high-pressure working condition is counteracted, the valve rod is prevented from making contact with the valve body due to stress deviation, and the axial stability of the valve rod is improved.

Description

Technical Field

[0001] The present application relates to the field of valve technology, and in particular to a valve stem fixing device. Background Art

[0002] In high-pressure valve applications (especially ball valves and split-stem plug valves), the axial stability of the valve stem directly determines the reliability of the valve.

[0003] Existing technologies generally employ an axially non-fixed valve stem design, which allows for slight axial displacement of the valve stem. To mitigate the impact of the medium's thrust, friction-reducing pads are typically added to the blowout-proof step on the valve stem, attempting to suppress the opening and closing torque by reducing the friction coefficient. However, this structure inherently only provides passive friction reduction and cannot completely offset the enormous axial thrust generated by the high-pressure medium. Under high-pressure operating conditions, excessive axial force will cause the friction-reducing pad to fail, triggering a sharp increase in the valve's opening and closing torque, resulting in crushing, straining, or even jamming of the valve stem, seriously threatening the safe operation of the system. Utility Model Content

[0004] The embodiments of the present application solve the technical problems raised in the background art by providing a valve stem fixing device.

[0005] An embodiment of the present application provides a valve stem fixing device, including a connecting shaft, a sealing cover assembly and two brackets; the two brackets are arranged opposite to each other, one end of each of which is fixedly connected to the side wall of the valve body, and the other end thereof jointly forms an annular bearing cavity coaxial with the valve stem; one end of the connecting shaft extends into the annular bearing cavity and forms a rigid axial constraint connection with the top of the valve stem; an axial bearing is provided between the inner side wall of the annular bearing cavity and the outer side wall of the connecting shaft, and the axial end faces of the axial bearing respectively abut against the corresponding bracket and the axial bearing surface of the connecting shaft; the sealing cover assembly is installed at the axial opening of the annular bearing cavity, and forms a sealed chamber with the outer wall of the connecting shaft and the side wall of the annular bearing cavity; the axial bearing is located in the sealed chamber.

[0006] In one possible implementation, the sealing cover assembly includes a bearing sealing plate and a bearing sealing cover; the bearing sealing plate is detachably connected to the first axial end face of the corresponding bracket, and a first sealing ring is provided between its inner side wall and the outer wall of the connecting shaft; the bearing sealing cover is detachably connected to the second axial end face of the corresponding bracket, and a second sealing ring is provided between its inner side wall and the outer wall of the connecting shaft; a third sealing ring is provided between the bearing sealing plate and the first axial end face of the corresponding bracket; a fourth sealing ring is provided between the bearing sealing cover and the second axial end face of the corresponding bracket.

[0007] In a possible implementation, the axial bearing is a thrust ball bearing or a thrust roller bearing; wherein the outer ring of the axial bearing is interference fit with the inner wall of the annular bearing cavity, and the inner ring is interference fit with the outer wall of the connecting shaft.

[0008] In a possible implementation, a cavity wall of the sealed cavity is provided with a grease injection nozzle for injecting grease into the sealed cavity.

[0009] In a possible implementation, a pressure relief valve is provided on the wall of the sealed chamber to balance the internal pressure of the sealed chamber.

[0010] In a possible implementation, a transmission head with a regular polygonal cross section is provided on the top of the valve stem; a slot corresponding to the transmission head is provided on the bottom of the connecting shaft; and the transmission head is axially plugged and fixed in the slot.

[0011] In one possible implementation, the inner side wall of the bearing seal plate is provided with an annular sealing groove, and the outer wall of the connecting shaft is provided with a corresponding radial boss; the first sealing ring is located in the annular sealing groove and forms a radial seal with the side wall of the radial boss.

[0012] One or more technical solutions provided in the embodiments of this application have at least the following technical effects:

[0013] The valve stem fixing device provided in the embodiment of the present application includes a connecting shaft, a sealing cover assembly and two brackets. The valve stem fixing device of the present application forms a rigid axial constraint connection with the valve stem through the connecting shaft, so that the valve stem and the connecting shaft are tightly fitted and there is no relative displacement, thereby offsetting the axial force generated by the medium under high-pressure working conditions, preventing the valve stem from contacting the valve body due to force offset, and thus completely offsetting the friction torque generated when the anti-blowout step of the valve stem contacts the valve body, directly reducing the valve opening and closing torque, improving the axial stability of the valve stem, and reducing performance degradation caused by mechanical wear; at the same time, the axial bearing is installed in a sealed chamber composed of the connecting shaft, the annular bearing cavity and the sealing cover assembly, and after being filled with grease, an independent lubrication environment is formed, which effectively isolates external impurities, provides anti-rust lubrication protection for the axial bearing, extends its service life, ensures long-term stable operation under high-pressure and high-load conditions, improves the reliability of the entire device, and achieves the comprehensive technical effects of reducing the valve opening and closing torque, improving the valve stem stability and extending the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments of the present application. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0015] Figure 1 A schematic structural diagram of the valve stem fixing device provided in an embodiment of the present application.

[0016] Icons: 1-connecting shaft; 2-sealing cover assembly; 21-bearing sealing plate; 22-bearing cover; 23-first sealing ring; 24-second sealing ring; 25-third sealing ring; 26-fourth sealing ring; 3-bracket; 4-axial bearing; 5-valve stem; 6-valve body; 7-transmission head. DETAILED DESCRIPTION

[0017] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0018] In the description of the embodiments of the present application, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limitations on the present application. The terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a communication between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0019] The embodiment of the present application provides a valve stem fixing device, such as Figure 1As shown. The valve stem fixing device includes a connecting shaft 1, a sealing cover assembly 2 and two brackets 3. The two brackets 3 are arranged opposite to each other, one end of which is fixedly connected to the side wall of the valve body 6, and the other end thereof jointly forms an annular bearing cavity coaxial with the valve stem 5. One end of the connecting shaft 1 extends into the annular bearing cavity and forms a rigid axial constraint connection with the top of the valve stem 5. An axial bearing 4 is provided between the inner side wall of the annular bearing cavity and the outer side wall of the connecting shaft 1, and the axial end faces of the axial bearing 4 respectively abut against the corresponding bracket 3 and the axial bearing surface of the connecting shaft 1. The sealing cover assembly 2 is installed at the axial opening of the annular bearing cavity, and forms a sealed chamber with the outer wall of the connecting shaft 1 and the side wall of the annular bearing cavity. The axial bearing 4 is located in the sealed chamber.

[0020] It should be noted that the valve stem fixing device of the present application forms a rigid axial constraint connection with the valve stem 5 through the connecting shaft 1, so that the valve stem 5 and the connecting shaft 1 are tightly fitted and have no relative displacement, offsetting the axial force generated by the medium under high-pressure conditions, avoiding the valve stem 5 from contacting the valve body 6 due to force offset, and thus completely offsetting the friction torque generated when the valve stem 5 anti-blowout step contacts the valve body 6, directly reducing the valve opening and closing torque, improving the axial stability of the valve stem 5, and reducing performance degradation caused by mechanical wear; at the same time, the axial bearing 4 is installed in a sealed chamber composed of the connecting shaft 1, the annular bearing cavity and the sealing cover assembly 2, and an independent lubrication environment is formed after being filled with grease, which effectively isolates external impurities, provides anti-rust lubrication protection for the axial bearing 4, extends its service life, ensures long-term stable operation under high-pressure and high-load conditions, improves the reliability of the entire device, and achieves the comprehensive technical effects of reduced valve opening and closing torque, improved stability of the valve stem 5 and extended service life.

[0021] In the embodiment of the present application, the sealing cover assembly 2 includes a bearing sealing plate 21 and a bearing sealing cover 22. The bearing sealing plate 21 is detachably connected to the first axial end face of the corresponding bracket 3, and a first sealing ring 23 is provided between the inner side wall thereof and the outer wall of the connecting shaft 1. The bearing sealing cover 22 is detachably connected to the second axial end face of the corresponding bracket 3, and a second sealing ring 24 is provided between the inner side wall thereof and the outer wall of the connecting shaft 1. A third sealing ring 25 is provided between the bearing sealing plate 21 and the first axial end face of the corresponding bracket 3. A fourth sealing ring 26 is provided between the bearing sealing cover 22 and the second axial end face of the corresponding bracket 3.

[0022] In the embodiment of the present application, the axial bearing 4 is a thrust ball bearing or a thrust roller bearing. The outer ring of the axial bearing 4 has an interference fit with the inner wall of the annular bearing cavity, while the inner ring has an interference fit with the outer wall of the connecting shaft 1. The interference fit of the present application ensures a tight, gap-free connection between the axial bearing 4, the annular bearing cavity, and the connecting shaft 1, effectively transmitting axial loads and improving the load-bearing capacity and stability of the valve stem fixture. Furthermore, the high precision and low friction characteristics of the thrust ball bearing or thrust roller bearing further reduce energy loss and frictional heat during valve opening and closing, extending the service life of the axial bearing 4 and the entire device, and ensuring reliable operation of the high-pressure valve under complex operating conditions.

[0023] In the embodiment of the present application, the cavity wall of the sealed chamber is provided with a grease injection nozzle for injecting grease into the sealed chamber. Specifically, the present application can provide a grease injection nozzle on the top of the bearing sealing plate 21.

[0024] In the embodiment of the present application, a pressure relief valve is provided on the wall of the sealed chamber to balance the internal pressure of the sealed chamber.

[0025] It should be noted that the sealed chamber of the present application further optimizes its functionality and reliability. Specifically, a grease nipple is provided on the wall of the sealed chamber, and the grease nipple can be precisely positioned on the top of the bearing sealing plate 21 to facilitate the injection of grease into the sealed chamber. This design not only simplifies the grease injection process, but also improves maintenance efficiency. In addition, a pressure relief valve is added to the wall of the sealed chamber, which can balance the pressure in the sealed chamber to prevent damage to the axial bearing 4 and the sealed chamber due to excessive or low pressure, further ensuring the stable operation and safety of the sealed chamber under high pressure and high load conditions.

[0026] In the embodiment of the present application, a transmission head 7 having a regular polygonal cross section is provided on the top of the valve stem 5. A slot corresponding to the transmission head 7 is provided at the bottom of the connecting shaft 1. The transmission head 7 is axially plugged and fixed in the slot.

[0027] Specifically, the drive head 7 and the slot have an interference fit. A radial threaded hole is provided on the outer wall of the connecting shaft 1, penetrating the sidewall of the connecting shaft 1 and extending into the slot. Once the drive head 7 is fully pressed into the slot, a set screw is threaded through the radial threaded hole, with its end pressing against (or inserting into) a pre-set pin hole in the sidewall of the drive head 7, preventing it from axially withdrawing.

[0028] It should be noted that the matching structure of the regular polygonal transmission head 7 and the slot not only ensures a stable axial connection between the valve stem 5 and the connecting shaft 1, preventing axial displacement of the valve stem 5, but also realizes synchronous rotation of the two during torque transmission through circumferential constraints, avoiding energy loss and mechanical wear caused by relative sliding, improving the accuracy and reliability of valve opening and closing operations, and at the same time extending the service life of the valve stem 5 and the connecting shaft 1, ensuring the efficient and stable operation of the high-pressure valve under complex working conditions.

[0029] In the embodiment of the present application, an annular sealing groove is provided on the inner sidewall of the bearing sealing plate 21, and a corresponding radial convex shoulder is provided on the outer wall of the connecting shaft 1. The first sealing ring 23 is located in the annular sealing groove and forms a radial seal with the sidewall of the radial convex shoulder.

[0030] It should be noted that the precise fit between the annular sealing groove and the radial boss enables the first sealing ring 23 to fit tightly against the side walls of the two, forming a reliable radial sealing structure, which effectively prevents the leakage of grease in the sealing chamber and the intrusion of external impurities and media, thereby ensuring the long-term stable operation of the axial bearing 4 in an independent lubrication environment and avoiding mechanical wear and performance degradation caused by sealing failure.

[0031] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0032] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A valve stem fixing device, characterized in that: It comprises a connecting shaft (1), a sealing cover assembly (2) and two brackets (3); The two brackets (3) are arranged opposite to each other, one end of each bracket is fixedly connected to the side wall of the valve body (6), and the other end of each bracket jointly forms an annular bearing cavity coaxial with the valve stem (5); One end of the connecting shaft (1) extends into the annular bearing cavity and forms a rigid axial constraint connection with the top of the valve stem (5); An axial bearing (4) is provided between the inner side wall of the annular bearing cavity and the outer side wall of the connecting shaft (1), and the axial end faces of the axial bearing (4) respectively abut against the corresponding axial bearing surfaces of the bracket (3) and the connecting shaft (1); The sealing cover assembly (2) is installed at the axial opening of the annular bearing cavity, and forms a sealing chamber with the outer wall of the connecting shaft (1) and the side wall of the annular bearing cavity; The axial bearing (4) is located in the sealed chamber.

2. The valve stem fixing device according to claim 1, characterized in that: The sealing cover assembly (2) comprises a bearing sealing plate (21) and a bearing sealing cover (22); The bearing sealing plate (21) is detachably connected to the first axial end surface of the corresponding bracket (3), and a first sealing ring (23) is provided between the inner side wall thereof and the outer wall of the connecting shaft (1); The bearing cover (22) is detachably connected to the corresponding second axial end face of the bracket (3), and a second sealing ring (24) is provided between the inner side wall thereof and the outer wall of the connecting shaft (1); A third sealing ring (25) is provided on the first axial end surface of the bearing sealing plate (21) and the corresponding bracket (3); A fourth sealing ring (26) is provided on the second axial end surface of the bearing cover (22) and the corresponding bracket (3).

3. The valve stem fixing device according to claim 1, characterized in that: The axial bearing (4) is a thrust ball bearing or a thrust roller bearing; wherein the outer ring of the axial bearing (4) is interference fit with the inner wall of the annular bearing cavity, and the inner ring is interference fit with the outer wall of the connecting shaft (1).

4. The valve stem fixing device according to claim 1, characterized in that: The cavity wall of the sealed cavity is provided with a grease injection nozzle for injecting grease into the sealed cavity.

5. The valve stem fixing device according to claim 1, characterized in that: The cavity wall of the sealed cavity is provided with a pressure relief valve for balancing the internal pressure of the sealed cavity.

6. The valve stem fixing device according to claim 1, characterized in that: A transmission head (7) having a regular polygonal cross section is provided on the top of the valve stem (5); The bottom of the connecting shaft (1) is provided with a slot corresponding to the transmission head (7); The transmission head (7) is axially plugged and fixed in the slot.

7. The valve stem fixing device according to claim 2, characterized in that: The inner side wall of the bearing sealing plate (21) is provided with an annular sealing groove, and the outer wall of the connecting shaft (1) is provided with a corresponding radial shoulder; The first sealing ring (23) is located in the annular sealing groove and forms a radial seal with the side wall of the radial shoulder.

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