Valve with valve rod padding evenly stressed

Abstract

The utility model belongs to the technical field of valves, and particularly relates to a valve with valve rod padding evenly stressed, which comprises a valve body, a valve rod, a stuffing box, combined padding, an elastic piece and a material pressing piece, the valve rod is arranged on the valve body, and the stuffing box is arranged on the valve body and located outside the valve rod. The combined packing is arranged in the packing box; the elastic piece is arranged at the bottom of the combined filler; the material pressing piece is arranged on the valve body and used for pressing the combined packing downwards. Compared with the prior art, the valve rod packing in the valve can be pressed in two directions, so that the whole valve rod packing is stressed uniformly, the sealing performance of the valve rod packing is improved, and the service life of the valve rod packing is prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of valves, and particularly relates to a valve with uniformly stressed valve stem packing. Background Art

[0002] Valve stem packing, also known as sealing packing or packing material, is used to fill the gap between the valve stem of a valve and the stuffing box (or stuffing gland) to prevent fluid from leaking from the inside of the valve to the external environment; such packing is crucial for ensuring the normal operation of the valve and maintaining the safety of the system.

[0003] The existing valve stem packing adopts a structure of pressing multiple layers of formed packing from the top. Since the longitudinal pressing force and the radial sealing force of the packing decrease along the depth direction of the stuffing box, it leads to an uneven distribution where the upper part of the packing is subjected to too much force and is prone to wear, while the lower part is subjected to too little force and the sealing is not tight. Therefore, it is necessary to improve the existing valve stem packing structure. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a valve with uniformly stressed valve stem packing for the above-mentioned existing technical problems. In this valve, the valve stem packing can be pressed in two directions, making the overall force on the valve stem packing uniform, improving the sealing performance of the valve stem packing and extending the service life of the valve stem packing.

[0005] In view of this, the utility model provides a valve with uniformly stressed valve stem packing, including:

[0006] A valve body, on which a valve stem is provided, and a stuffing box is provided outside the valve stem on the valve body;

[0007] A combined packing, which is arranged in the stuffing box;

[0008] An elastic member, which is arranged at the bottom of the combined packing;

[0009] A pressing member, which is arranged on the valve body and is used to press the combined packing in the stuffing box.

[0010] In this technical solution, after installing the valve stem and the valve body, first place the elastic member into the stuffing box, then place the combined packing into the stuffing box, and then press the combined packing in the stuffing box through the pressing member. While the pressing member presses the combined packing, the combined packing squeezes the elastic member, and the elastic member will apply an upward pressing force to the bottom of the combined packing, making the forces on the combined packing at different depths relatively uniform, balancing the frictional forces between the combined packing, the valve stem and the stuffing box, and also reducing the pressing force of the pressing member.

[0011] In the above technical solution, further, the pressure member includes an abutting ring and a pressure ring. The lower end of the abutting ring extends into the stuffing box and contacts the top of the combined packing. The pressure ring is arranged on the side of the abutting ring away from the valve body, and the distance between the pressure ring and the valve body is adjustable.

[0012] In the above technical solution, further, a threaded hole is provided on the surface of the valve body near the pressure ring. A screw rod is rotatably connected to the pressure ring. One end of the screw rod is threadedly connected to the threaded hole, and a disc spring is sleeved outside the screw rod.

[0013] In the above technical solution, further, a connecting column is provided on the surface of the valve body near the pressure ring. A connecting through groove is provided on the pressure ring. A plurality of slot holes are arranged at intervals along the length direction of the connecting column. The longitudinal section of the slot hole is wedge-shaped. A movable wedge-shaped seat is provided on the pressure ring. When the wedge-shaped seat is inserted into the slot hole, the pressure ring is pushed towards the valve body.

[0014] In the above technical solution, further, the combined packing includes two groups of packings distributed at intervals along the axial direction of the valve stem. A metal spacer ring is provided between the two groups of packings. An oil injection hole is provided on the valve body. A through hole is provided on the metal spacer ring, and the through hole conducts the oil injection hole and the valve stem.

[0015] In the above technical solution, further, a sealing ring is provided on the metal spacer ring.

[0016] In the above technical solution, further, a packing gasket is provided at the bottom of the combined packing, and an elastic member is provided between the packing gasket and the bottom surface of the stuffing box.

[0017] In the above technical solution, further, the elastic member is a corrugated spring.

[0018] The beneficial effects of the present utility model are:

[0019] 1. By arranging an elastic member at the bottom of the combined packing, while pressing the combined packing from the top, the elastic member will provide an upward pressing force to the combined packing at the bottom of the stuffing box. In this way, the sealing performance at the bottom of the combined packing can be enhanced, and the friction between the combined packing and the valve stem and the stuffing box can be balanced, reducing the wear of the combined packing during use and prolonging the service life of the valve stem packing.

[0020] 2. By designing the pressure member into an abutting ring and a pressure ring, and realizing the adjustment of the distance between the pressure ring and the valve body through the cooperation of the screw rod and the threaded hole, and sleeving a disc spring outside the screw rod. In this way, when pressing the combined packing, the disc spring is in a compressed state. When part of the combined packing is worn, the pressing force and sealing performance of the combined packing can be automatically compensated by the elastic force of the disc spring and the elastic member, prolonging the service life of the combined packing.

[0021] 3. By designing the adjustment of the spacing between the pressure ring and the valve body as the cooperation of the connecting column, the connecting through groove, multiple slots, and the wedge-shaped seat, only by controlling the depth of the wedge-shaped seat inserted into the corresponding slot, the pressing force of the combined packing can be finely adjusted, and the cooperation between the wedge-shaped seat and the slot is not easily invalidated after long-term use, with a long service life.

[0022] 4. By designing the combined packing into two groups of packings distributed at intervals along the axial direction of the valve stem, a metal spacer ring is arranged between the two groups of packings, through holes are opened on the spacer ring, an oil injection hole is opened on the valve body, and the oil injection hole is communicated with the valve stem through the through holes. In this way, lubricating oil can be injected into the outer wall of the valve stem through the oil injection hole when needed, avoiding the valve stem from rusting and failing, and prolonging the service life of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 It is a three-dimensional structural schematic diagram of the present invention.

[0025] Figure 2 It is a first structural schematic diagram of the valve stem packing in the present invention.

[0026] Figure 3 For Figure 2 the partial enlarged schematic diagram at A in

[0027] Figure 4 It is a structural schematic diagram of the wave spring in the present invention.

[0028] Figure 5 It is a force analysis schematic diagram of the valve stem packing in the present invention and the valve stem packing in the prior art.

[0029] Figure 6 It is a second structural schematic diagram of the valve stem packing in the present invention.

[0030] The marks in the figure are shown as:

[0031] 1. Valve body; 2. Valve stem; 3. Stuffing box; 4. Combined packing; 401. Braided packing; 402. Molded packing; 5. Wave spring; 6. Contact ring; 7. Pressure ring; 8. Threaded hole; 9. Screw; 10. Belleville spring; 11. Connecting column; 12. Connecting through groove; 13. Slot; 14. Wedge-shaped seat; 15. Metal spacer ring; 1501. Through hole; 16. Oil injection hole; 17. Sealing ring; 18. Packing pad; Specific embodiments

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the protection scope of the present utility model.

[0033] In the description of the present utility model, it should be noted that the terms used here are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. For the convenience of description, the dimensions of the various parts shown in the drawings are not drawn according to the actual proportional relationship. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the said technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0034] Embodiment 1

[0035] This embodiment provides a valve with uniform force on the packing of the valve stem 2, including: a valve body 1, a valve stem 2, a stuffing box 3, a combined packing 4, an elastic member, and a pressing member.

[0036] Please refer to Figure 1 , the valve body 1 is a valve product in the prior art. A valve stem 2 is provided on the valve body 1, and the valve is opened and closed by the rotation of the valve stem 2. A stuffing box 3 is provided outside the valve stem 2 on the valve body 1, and the stuffing box 3 is an annular groove;

[0037] The combined packing 4 is arranged in the stuffing box 3. In this embodiment, the combined packing 4 can be selected from braided packing 401 or molded packing 402, as well as a combination of the two. The braided packing 401 is a sealing material formed by braiding fibers or wires into a specific structure, which has good adaptability and a relatively simple installation process. The molded packing 402 is a sealing material pre-manufactured according to specific shapes and dimensions. Compared with the braided packing 401, the molded packing 402 is more convenient and fast to install and can provide a more consistent sealing effect;

[0038] Please refer to Figure 2, a packing pad 18 is provided at the bottom of the combined packing 4. The packing pad 18 is made of rigid material, and the elastic member is arranged between the packing pad 18 and the bottom surface of the stuffing box 3. In this embodiment, the elastic member is selected as the wave spring 5, and the structure of the wave spring 5 is as Figure 4 shown. The characteristic of the wave spring 5 is that it has a wavy or serrated outer shape, can provide a large elastic force in a small space, and compared with the traditional helical spring, the wave spring 5 can achieve a more compact design and higher load capacity;

[0039] The pressing member is arranged on the valve body 1 to press the combined packing 4 tightly in the stuffing box 3. For details, please refer to Figure 2 , the pressing member includes an abutting ring 6 and a pressing ring 7. The lower end of the abutting ring 6 extends into the stuffing box 3 and contacts the top of the combined packing 4. The pressing ring 7 is arranged on the side of the abutting ring 6 away from the valve body 1, and the distance between the pressing ring 7 and the valve body 1 is adjustable. After the pressing ring 7 contacts the top of the abutting ring 6, when the pressing ring 7 is adjusted towards the valve body 1, it can push the abutting ring 6 downward to tightly press the combined packing 4;

[0040] In this embodiment, a threaded hole 8 is provided on the surface of the valve body 1 near the pressing ring 7. A screw rod 9 is rotatably connected to the pressing ring 7. One end of the screw rod 9 is threadedly connected to the threaded hole 8. A disc spring 10 is sleeved outside the screw rod 9. The disc spring 10 is a disc-shaped spring with a conical cross-section, which can provide a large elastic force in a small space and can withstand a high load. The two ends of the disc spring 10 can be respectively connected to the fixed end of the screw rod 9 and the pressing ring 7, or respectively connected to the pressing ring 7 and the valve body 1. In this embodiment, by rotating the screw rod 9, the distance between the pressing ring 7 and the valve body 1 can be adjusted, so as to tightly press and loosen the abutting ring 6;

[0041] Please refer to Figure 1 , in this embodiment, one screw rod 9, one threaded hole 8 and a set of disc springs 10 form a set of adjusting structures. A plurality of sets of adjusting structures are arranged at intervals along the circumferential direction on the pressing ring 7, so that the forces at each position are relatively uniform after the combined packing 4 is tightly pressed.

[0042] In this embodiment, after the valve stem 2 and the valve body 1 are installed, first place the elastic member into the stuffing box 3, then place the combined packing 4 into the stuffing box 3, and then use the pressing member to tightly press the combined packing 4 in the stuffing box 3. While the pressing member tightly presses the combined packing 4, the combined packing 4 squeezes the elastic member, and the elastic member will apply an upward pressing force to the bottom of the combined packing 4, which can enhance the sealing performance at the bottom of the combined packing 4 and can also balance the friction between the combined packing 4 and the valve stem 2 and the stuffing box 3; Please refer to Figure 5, through the setting of this embodiment, compared with directly installing and pressing the combined packing 4 in the prior art, the axial pressing forces received by the top and bottom of the combined packing 4 are relatively balanced, and the radial sealing forces received by the top and bottom of the combined packing 4 are also relatively balanced. In this way, the wear during the use of the combined packing 4 can be reduced, and the service life of the packing of the valve stem 2 can be extended. In addition, when part of the combined packing 4 is worn, the pressing force and sealing performance of the combined packing 4 can be automatically compensated by the elastic forces of the disc spring 10 and the elastic member, and the service life of the combined packing 4 can be extended.

[0043] Embodiment 2

[0044] This embodiment provides a valve with uniformly stressed packing for the valve stem 2. The difference from Embodiment 1 is that the adjustment method of the distance between the packing pressing ring 7 and the valve body 1 in this embodiment is different;

[0045] In this embodiment, please refer to Figure 6 , on the surface of the valve body 1 near the packing pressing ring 7, a connecting column 11 is provided. A connecting through groove 12 is formed on the packing pressing ring 7. A plurality of slot grooves 13 are spaced along the length direction on the connecting column 11. The longitudinal section of the slot groove 13 is wedge-shaped. A movable wedge-shaped seat 14 is provided on the packing pressing ring 7. When the wedge-shaped seat 14 is inserted into the slot groove 13, the packing pressing ring 7 is pushed towards the valve body 1;

[0046] Compared with Embodiment 1, in Embodiment 1, the screw 9 and the threaded hole 8 are connected by threads. After long-term static state or thread wear, the threaded connection will fail, which may make it difficult to disassemble between the screw 9 and the threaded hole 8. In this embodiment, through the cooperation of the plurality of slot grooves 13 and the wedge-shaped seat 14, after the connecting column 11 passes through the connecting through groove 12, the end with a smaller cross-sectional area of the wedge-shaped seat 14 is inserted into the corresponding slot groove 13, and the wedge-shaped seat 14 is continuously pushed into the slot groove 13. During this process, the packing pressing ring 7 is pushed towards the valve body 1 to realize the extrusion and abutment of the abutting ring 6 and the combined packing 4;

[0047] In this embodiment, the contact surface between the wedge-shaped seat 14 and the slot groove 13 is rough, which can prevent the wedge-shaped seat 14 from accidentally coming out of the slot groove 13. In addition, a disc spring 10 or a traditional helical spring can be sleeved outside the connecting column 11. During the process of the wedge-shaped seat 14 being inserted into the slot groove 13, the disc spring 10 or the helical spring can be compressed, so that the pressing force and sealing performance of the combined packing 4 can be automatically compensated by the elastic forces of the disc spring 10 or the helical spring and the elastic member.

[0048] In addition, in this embodiment, by only controlling the depth of the wedge-shaped seat 14 inserted into the corresponding slot groove 13, the pressing force of the combined packing 4 can be finely adjusted, and the cooperation between the wedge-shaped seat 14 and the slot groove 13 is not easy to fail after long-term use, and the service life is long.

[0049] Embodiment 3

[0050] This embodiment provides a valve with uniform force on the packing of the valve stem 2. In addition to the technical solutions of the above embodiment, it also has the following technical features;

[0051] In this embodiment, please refer to Figure 2 , the combined packing 4 includes two groups of packings distributed at intervals along the axial direction of the valve stem 2. A metal spacer ring 15 is provided between the two groups of packings. An oil injection hole 16 is provided on the valve body 1. A through hole 1501 is provided on the metal spacer ring 15. The through hole 1501 conducts the oil injection hole 16 and the valve stem 2;

[0052] In this embodiment, lubricating oil can be injected into the outer wall of the valve stem 2 through the oil injection hole 16 when needed, to avoid the valve stem 2 from rusting and failing, and to extend the service life of the valve;

[0053] One end port of the oil injection hole 16 away from the through hole 1501 is connected through a sealing joint. When it is not necessary to inject lubricating oil into the valve stem 2, the sealing joint can seal the oil injection hole 16 to ensure the sealing performance of the valve. When oil injection is required, the oil injection device is connected to the sealing joint, and lubricating oil is injected into the outer wall of the valve stem 2 through the passage formed by the oil injection hole 16 and the through hole 1501;

[0054] In this embodiment, a sealing ring 17 is provided on the metal spacer ring 15, which further ensures the sealing performance of the valve stem 2 and optimizes the force state of the packing.

[0055] The embodiments of the present utility model have been described above in conjunction with the accompanying drawings. Without conflict, the embodiments and the features in the embodiments in this application can be combined with each other. This application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of this application, those of ordinary skill in the art can also make many forms without departing from the purpose of this application and the scope protected by the claims, and all belong to the protection scope of this application.

Claims

1. A valve with uniformly stressed valve stem packing, comprising: A valve body (1) provided with a valve stem (2) thereon, and a stuffing box (3) is provided outside the valve stem (2) on the valve body (1); It is characterized in that it further comprises: A combined packing (4) provided in the stuffing box (3); An elastic member provided at the bottom of the combined packing (4); A pressure piece provided on the valve body (1) for pressing the combined packing (4) tightly in the stuffing box (3).

2. The valve with uniform force on the valve stem packing according to claim 1, wherein: The pressure piece includes a contact ring (6) and a pressure ring (7). The lower end of the contact ring (6) extends into the stuffing box (3) to contact the top of the combined packing (4). The pressure ring (7) is provided on the side of the contact ring (6) away from the valve body (1), and the distance between the pressure ring (7) and the valve body (1) is adjustable.

3. The valve with uniform force on the valve stem packing according to claim 2, characterized in that: A threaded hole (8) is provided on the surface of the valve body (1) near the pressure ring (7). A screw rod (9) is rotatably connected to the pressure ring (7). One end of the screw rod (9) is threadedly connected to the threaded hole (8), and a disc spring (10) is sleeved outside the screw rod (9).

4. A valve with uniform stress on the valve stem packing according to claim 2, characterized in that: A connecting column (11) is provided on the surface of the valve body (1) near the pressure ring (7). A connecting through groove (12) is provided on the pressure ring (7). A plurality of slots (13) are provided at intervals along the length direction on the connecting column (11). The longitudinal section of the slot (13) is wedge-shaped. A movable wedge-shaped seat (14) is provided on the pressure ring (7). When the wedge-shaped seat (14) is inserted into the slot (13), the pressure ring (7) is pushed towards the valve body (1).

5. A valve with uniformly stressed valve stem packing according to claim 3 or 4, characterized in that: The combined packing (4) includes two groups of packings distributed at intervals along the axial direction of the valve stem (2). A metal spacer ring (15) is provided between the two groups of packings. An oil injection hole (16) is provided on the valve body (1). A through hole (1501) is provided on the metal spacer ring (15). The through hole (1501) conducts the oil injection hole (16) and the valve stem (2).

6. The valve with uniform force on the valve stem packing according to claim 5, characterized in that: A sealing ring (17) is provided on the metal spacer ring (15).

7. A valve with uniformly stressed valve stem packing according to claim 1, characterized in that: A packing pad (18) is provided at the bottom of the combined packing (4). The elastic member is provided between the packing pad (18) and the bottom surface of the stuffing box (3).

8. A valve with uniformly stressed valve stem packing according to claim 7, characterized in that: The elastic member is a corrugated spring (5).

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