Flat gate valve capable of reducing torque

Abstract

The utility model belongs to the field of gate valves, and particularly relates to a flat gate valve capable of reducing torque, which comprises a valve body, a gate plate, a valve rod, a valve cover, a support, a valve rod nut and a nut gland, the valve rod nut is in threaded connection outside the valve rod and axially limited between the support and the nut gland, and the upper end face of the valve rod nut is in ball end face fit with the nut gland. And / or the lower end face of the valve rod nut is in spherical end face fit with the bracket. The flat end face matching of the upper end and / or the lower end of the valve rod nut is improved into the ball end face matching, so that the contact area of the valve rod nut is reduced, the friction force during rotation of the valve rod nut is further reduced, and the torque during opening and closing of the gate valve can be reduced.

Description

Technical Field

[0001] The utility model belongs to the field of gate valves, and particularly relates to a flat gate valve with reduced torque. Background Art

[0002] At present, the structure of a common flat gate valve is as Figure 1 shown, including a valve body 1, a gate plate 2, a valve stem 3, a valve cover 4, a bracket 5, a valve stem nut 6, a nut gland 7, 8. The valve stem nut 6 is threadedly connected to the outside of the valve stem 3 and axially limited between the bracket 5 and the nut gland 7. 8 is sleeved outside the valve stem nut 6 and is in circumferential linkage cooperation with the valve stem nut 6. When 8 rotates, it drives the valve stem nut 6 to rotate, thereby realizing the axial up and down movement of the valve stem 3. As Figure 2 、 Figure 3 shown, the upper and lower end faces of the valve stem nut 6 are in flat end face cooperation with the bracket 5 and the nut gland 7 respectively. The contact area is large and the friction force is large. At present, in order to reduce the influence of the friction force of the rotation of the valve stem nut 6. In addition, in order to avoid the problem that the friction force increases due to corrosion of the contact part, the common treatment methods and corresponding problems are as follows: 1. The contacting flat end faces are blackened, but they are prone to rust after a long time; 2. Antirust oil is applied on the contacting flat end faces, but the shelf life is short. Content of the Utility Model

[0003] The purpose of the utility model is to overcome the defects and deficiencies existing in the prior art, and provide a flat gate valve with reduced torque.

[0004] The technical solution adopted by the utility model is as follows: A flat gate valve with reduced torque, including a valve body, a gate plate, a valve stem, a valve cover, a bracket, a valve stem nut, and a nut gland. The valve stem nut is threadedly connected to the outside of the valve stem and axially limited between the bracket and the nut gland. A spherical end face fit is formed between the upper end face of the valve stem nut and the nut gland, and / or a spherical end face fit is formed between the lower end face of the valve stem nut and the bracket.

[0005] A spherical surface is formed by the convexity of the upper end face of the valve stem nut, and the corresponding mating surface of the nut gland is a flat surface; a spherical surface is formed by the convexity of the lower end face of the valve stem nut, and the corresponding mating surface of the bracket is a flat surface.

[0006] A first hard alloy surfacing layer is formed on the flat surface corresponding to the upper end face of the valve stem nut of the nut gland.

[0007] A second hard alloy surfacing layer is formed on the flat surface corresponding to the lower end face of the valve stem nut of the bracket.

[0008] The valve stem includes a driving section, a sealing section, and a connecting section connected in sequence. The driving section is provided with an external thread, and the valve stem nut is in threaded connection and cooperation with the driving section. The sealing section is in sealing cooperation with the valve cover, and the connecting section is located between the valve cover and the valve body to be connected to the gate plate.

[0009] The outer diameter D of the sealing section is greater than the outer diameter d of the driving section.

[0010] The sealing section is of a hollow structure.

[0011] The valve stem is composed of three rod bodies connected by welding.

[0012] The sealing structure between the sealing section and the valve cover includes a packing, a Y-shaped sealing ring, and a sealing ring stacked in sequence from bottom to top.

[0013] The beneficial effects of the present utility model are as follows: The present utility model improves the flat end face cooperation at the upper end and / or the lower end of the valve stem nut to a spherical end face cooperation, thereby reducing the contact area of the valve stem nut and further reducing the friction force when the valve stem nut rotates. Therefore, the torque during the opening and closing of the gate valve can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, obtaining other drawings based on these drawings still belongs to the scope of the present utility model.

[0015] Figure 1 is the structure of a flat gate valve in the prior art;

[0016] Figure 2 is Figure 1 the enlarged schematic view of part A in

[0017] Figure 3 is the schematic structural view of the flat gate valve in an open state according to an embodiment of the present utility model;

[0018] Figure 4 is the schematic view of the valve stem nut mating structure according to an embodiment of the present utility model;

[0019] Figure 5 is Figure 4 the enlarged schematic view of part A in

[0020] Figure 6 is the schematic structural view of the flat gate valve in a closed state according to an embodiment of the present utility model;

[0021] Figure 7 isFigure 6 Schematic enlarged view of part A

[0022] In the figure, valve body - 1, gate - 2, valve stem - 3, driving section - 3A, sealing section - 3B, connecting section - 3C, valve cover - 4, bracket - 5, second hard alloy surfacing layer - 501, valve stem nut - 6, upper end face of nut - 601, lower end face of nut - 602, nut gland - 7, first hard alloy surfacing layer - 701, packing - 8, Y - type sealing ring - 9, sealing ring - 10. Specific implementation mode

[0023] To make the purpose, technical solution and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0024] It should be noted that all the expressions using "first" and "second" in the embodiments of the present utility model are for distinguishing two entities or parameters with the same name but different, so "first" and "second" are only for the convenience of expression and should not be understood as a limitation to the embodiments of the present utility model. This will not be elaborated one by one in the subsequent embodiments.

[0025] The direction and position terms mentioned in the present utility model, such as up, down, front, back, left, right, inside, outside, top, bottom, side, etc., are only with reference to the direction or position of the accompanying drawings. Therefore, the direction and position terms used are for explaining and understanding the present utility model, rather than a limitation to the protection scope of the present utility model.

[0026] As Figures 3 - 7 shown, a flat gate valve for reducing torque includes a valve body 1, a gate 2, a valve stem 3, a valve cover 4, a bracket 5, a valve stem nut 6, and a nut gland 7. The valve body 1 is connected to the valve cover 4 to form a valve cavity. The gate 2 is located in the valve cavity. The valve stem 3 passes through the valve cover 4 and is in sealing cooperation with the valve cover 4. The bracket 5 is connected above the valve cover 4. As Figure 4 shown, the valve stem nut 6 is threadedly connected to the outside of the valve stem 3 and axially limited between the bracket 5 and the nut gland 7. A spherical end face fit is formed between the upper end face of the valve stem nut 6 and the nut gland 7, and / or a spherical end face fit is formed between the lower end face of the valve stem nut 6 and the bracket 5. The spherical end face fit means that one end face is spherical, and the other mating end face can be a plane, a concave spherical surface or other special shapes. Compared with the flat end face fit, the contact area can be greatly reduced, thereby further reducing the friction when the valve stem nut rotates. Therefore, the torque during the opening and closing of the gate valve can be reduced.

[0027] Specifically, as Figure 5 shown, the upper end face 601 of the nut of the valve stem nut 6 protrudes to form a spherical surface, and the corresponding mating surface of the nut gland 7 is a plane; the lower end face 602 of the nut of the valve stem nut 6 protrudes to form a spherical surface, and the corresponding mating surface of the bracket 5 is a plane.

[0028] Furthermore, a first hard alloy surfacing layer 701 is formed on the plane of the nut gland 7 that cooperates with the upper end surface of the valve stem nut 6, and a second hard alloy surfacing layer 501 is formed on the plane of the bracket 5 that cooperates with the lower end surface of the valve stem nut 6. Through hard alloy surfacing, the friction caused by rust is avoided, and the increase in friction caused by rust is further avoided.

[0029] Furthermore, the valve stem 3 includes a driving section 3A, a sealing section 3B, and a connecting section 3C connected in sequence. The driving section 3A is provided with an external thread, and the valve stem nut 6 is in threaded connection and cooperation with the driving section 3A. The sealing section 3B is in sealing cooperation with the valve cover 4, and the connecting section 3C is located between the valve cover 4 and the valve body 1 to be connected to the gate plate 2. The valve stem 3 of this embodiment has a stepped diameter structure, and the outer diameter D of the sealing section 3B is larger than the outer diameter d of the driving section 3A. Compared with the prior art, the outer diameter of the sealing section 3B in this embodiment is increased, so that the stress cross-section of the valve stem is increased, and the thrust of the medium pushing the valve stem outwards is used to offset the friction between the gate plate and the valve seat, achieving a light effect when opening; and the slenderness ratio of the valve stem is reduced, making the processing technology of the valve stem better;

[0030] Furthermore, the sealing section 3B is a hollow structure, which makes the anti-torsion effect of the valve stem better and reduces the weight of the valve stem.

[0031] Furthermore, the valve stem 3 is composed of three rod bodies welded together, and the hollow cylindrical part is welded to both ends to form a hollow sealing section 3B.

[0032] Furthermore, as Figure 7 shown, the sealing structure between the sealing section 3B and the valve cover 4 includes a packing 8, a Y-shaped sealing ring 9, and a sealing ring 10 stacked in sequence from bottom to top.

[0033] The above-disclosed are only the preferred embodiments of the present invention. Of course, the scope of the rights of the present invention cannot be limited by this. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A flat gate valve for reducing torque, comprising a valve body (1), a gate (2), a valve stem (3), a valve cover (4), a bracket (5), a valve stem nut (6), and a nut gland (7). The valve stem nut (6) is threadedly connected to the outside of the valve stem (3) and axially limited between the bracket (5) and the nut gland (7), and is characterized in that: A spherical end face fit is formed between the upper end face of the valve stem nut (6) and the nut gland (7), and / or a spherical end face fit is formed between the lower end face of the valve stem nut (6) and the bracket (5).

2. The reduced-torque flat gate valve according to claim 1, wherein: The upper end face (601) of the nut of the valve stem nut (6) protrudes to form a spherical surface, and the corresponding mating surface of the nut gland (7) is a flat surface; the lower end face (602) of the nut of the valve stem nut (6) protrudes to form a spherical surface, and the corresponding mating surface of the bracket (5) is a flat surface.

3. The reduced-torque parallel slide valve according to claim 2, wherein: A first hard alloy surfacing layer (701) is formed on the flat surface of the nut gland (7) corresponding to the upper end face of the valve stem nut (6).

4. The reduced-torque parallel slide valve according to claim 2, wherein: A second hard alloy surfacing layer (501) is formed on the flat surface of the bracket (5) corresponding to the lower end face of the valve stem nut (6).

5. The torque-reducing flat gate valve according to claim 1, wherein: The valve stem (3) includes a driving section (3A), a sealing section (3B), and a connecting section (3C) connected in sequence. The driving section (3A) is provided with an external thread, the valve stem nut (6) is in threaded connection with the driving section (3A), the sealing section (3B) is in sealing cooperation with the valve cover (4), and the connecting section (3C) is located between the valve cover (4) and the valve body (1) to be connected to the gate plate (2).

6. The reduced-torque parallel slide valve according to claim 5, wherein: The outer diameter D of the sealing section (3B) is greater than the outer diameter d of the driving section (3A).

7. The reduced-torque flat gate valve according to claim 6, wherein: The sealing section (3B) is a hollow structure.

8. The reduced-torque parallel slide valve according to claim 7, wherein: The valve stem (3) is composed of three rod bodies welded together.

9. The torque-reducing flat gate valve according to claim 5, wherein: The sealing structure between the sealing section (3B) and the valve cover (4) includes a packing (8), a Y-shaped sealing ring (9), and a sealing ring (10) stacked in sequence from bottom to top.

Images