Seal mechanism, valve, and rotary joint

Abstract

The sealing mechanism (10) of the present invention comprises: a shaft portion (21) having a shaft portion (24); a large diameter portion (25) having a diameter greater than that of the shaft portion (24); and a round cover portion (26) disposed at one end of the large diameter portion (25) and the circumferential surface of the shaft portion (24); a spring portion (22) disposed at the other end of the large diameter portion (25); an elastic body (23) being placed on a recess (first recess (27)) formed on the circumferential surface of the large diameter portion (25); and an outer cylinder portion (30) covering the shaft portion (21), the spring portion (22) and the elastic body (23), having a tapered portion (31) formed along the curved surface of the round cover portion (26), and contacting at least the large diameter portion (25) and the round cover portion (26) of the shaft portion (21).

Description

Technical Field

[0001] This invention relates to sealing mechanisms, valves, and rotary joints. Prior Technology

[0002] To date, various valves are known for controlling the flow of fluids in piping systems. For example, Japanese Utility Model Publication No. JPH01116287U discloses a ball valve that opens and closes by rotating the valve body with the operation of a handle, and discloses a stem sealing device particularly suitable for ball valves. Summary of the Invention

[0003] In the ball valve described in Japanese patent number JPH01116287U (Jizenpei 01-116287), a large space is filled with various components, thus increasing the number of parts. Furthermore, since the sealing function is expected to be achieved through the elastic deformation of the gasket material, elastic deformation must be considered in the design, complicating the design of manufacturing tolerances.

[0004] The present invention was developed in view of the above-mentioned problems, and its purpose is to provide a sealing mechanism, valve and rotary joint that can achieve sealing function through a simple structure.

[0005] [Methods used to solve problems] The sealing mechanism of the present invention comprises: The shaft portion includes: a shaft portion; a large-diameter portion having a diameter larger than that of the aforementioned shaft portion; and a round cover portion provided at one end of the aforementioned large-diameter portion and on the circumference of the aforementioned shaft portion. The spring portion is located at the other end of the aforementioned large-diameter portion; The elastomer is placed on the recess formed on the circumferential surface of the aforementioned large-diameter portion; and The outer cylinder portion covers the aforementioned shaft portion, the aforementioned spring portion, and the aforementioned elastic body, and has a tapered portion formed along the curved surface of the aforementioned round cover portion, and is in contact with at least the aforementioned large-diameter portion of the aforementioned shaft portion and the aforementioned round cover portion.

[0006] In the sealing mechanism of the present invention, The conical angle of the aforementioned conical part can be an angle of 30° or more but less than 180°.

[0007] The sealing mechanism of this invention may include: The bearing is mounted on the aforementioned spring portion; and The fixing component is used to fix the aforementioned bearing.

[0008] In the sealing mechanism of the present invention, The aforementioned elastomer can be an O-ring.

[0009] In the sealing mechanism of the present invention, The other end face of the aforementioned large-diameter portion may extend radially relative to the long axis of the aforementioned shaft portion.

[0010] In the sealing mechanism of the present invention, The inner circumferential surface of the aforementioned outer cylinder can contact the aforementioned elastomer.

[0011] The valve system of the present invention includes the aforementioned sealing mechanism.

[0012] The rotary joint of the present invention is equipped with the aforementioned sealing mechanism. Simple Explanation of the Diagram

[0013] Figure 1 is a schematic diagram of the valve structure of this embodiment. Figure 2 shows a modified example of this embodiment and a schematic diagram of the configuration of a rotary joint having the sealing mechanism of this embodiment. Implementation

[0014] The sealing mechanism 10 and valve 1 of this embodiment will now be described with reference to the drawings. Figures 1 and 2 are diagrams showing the sealing mechanism 10 and valve 1 of this embodiment. Figure 1 is a schematic diagram showing the configuration of valve 1 of this embodiment. Figure 2 is a modified example of this embodiment, and a schematic diagram showing the configuration of the rotary joint 100 equipped with the sealing mechanism 10 of this embodiment.

[0015] First, the sealing mechanism 10 of this embodiment will be described. As shown in Figure 1, the sealing mechanism 10 of this embodiment includes a valve stem 20 and an outer cylinder portion 30. The valve stem 20 includes a shaft portion 21. The outer cylinder portion 30 covers the valve stem 20. In this specification, a ball valve is used as an example valve 1 for description.

[0016] The valve stem 20 has a shaft portion 21, a spring portion 22 that applies a spring force to the ball 70, and an elastic body 23 installed on the circumferential surface of the shaft portion 21. The ball 70 is rotated by rotating about the axis of the valve stem 20.

[0017] The shaft portion 21 includes: a shaft portion 24, which is a rod-shaped or cylindrical base shaft with a long axis; a large-diameter portion 25, which has a diameter greater than that of the shaft portion 24 and constitutes part of the shaft portion 24; and a hemispherical cover portion 26, which is disposed from one end of the large-diameter portion 25 toward the circumference of the shaft portion 24.

[0018] The shaft 24 is a rod-shaped or cylindrical metal component. One end of the shaft 24 is connected to the ball 70, and power is transmitted to the ball 70 through rotational motion. The other end of the shaft 24 is connected to the handle 40, and the shaft 24 is rotated by rotating the handle 40 clockwise or counterclockwise.

[0019] The large-diameter portion 25 is the portion where the shaft portion 24 is enlarged, and it occupies a continuous range within the shaft portion 24. Within the shaft portion 24, the large-diameter portion 25 is provided from the center of the shaft portion 24 toward one end. The diameter of the large-diameter portion 25 can be set to a range of 1.5 to 2.5 times the diameter of the shaft portion 24. When the diameter of the large-diameter portion 25 is less than 1.5 times the diameter of the shaft portion 24, the hemispherical portion of the dome portion 26 becomes smaller, thus reducing its practicality from a manufacturing tolerance perspective. Furthermore, when the diameter of the large-diameter portion 25 exceeds 2.5 times the diameter of the shaft portion 24, the dimensions at the time of product manufacturing may become excessively large. Additionally, to ensure the shaft functions properly, the length ratio of the large-diameter portion 25 to the shaft portion 24 along its major axis can be set to a range of 1:3 to 1:10.

[0020] Furthermore, a first recess 27 is formed on the circumferential surface of the large-diameter portion 25. The first recess 27 is a recess formed along the circumferential direction of the circumferential surface of the large-diameter portion 25, and it is formed in an endless shape. From the viewpoint of not diminishing the function of the elastomer 23 housed therein, the ratio of the depth to the width of the first recess 27 can be set to a range of 1:1.1 or more and 1:3 or less.

[0021] The dome portion 26 is a hemispherical portion extending from one end of the large-diameter portion 25 toward the circumference of the shaft portion 24. The central axes of the dome portion 26 and the shaft portion 24 overlap. Furthermore, the dimensions of the hemispherical surface of the dome portion 26 vary according to the curvature corresponding to the dimensions of the shaft portion 24 and the large-diameter portion 25.

[0022] The spring portion 22 is a mechanical element disposed at the other end of the large-diameter portion 25. It may be, for example, a member mounted on the other end face of the large-diameter portion 25, or one or more members that can apply a springing force to the other end via a member mounted on the other end face of the large-diameter portion 25, and may be a member that can apply a springing force to the outer cylinder portion 30. For example, a leaf spring can be used as the spring portion 22. Furthermore, the length of the spring portion 22 disposed at the other end of the large-diameter portion 25 perpendicular to the springing direction is less than or equal to the radial length of the other end face of the large-diameter portion 25. When using one spring portion 22, it is arranged along the circumferential surface of the other end of the large-diameter portion 25 to evenly spring towards the outer cylinder portion 30. When using multiple spring portions 22, they are evenly spaced apart on the circumferential surface of the other end of the large-diameter portion 25 to evenly spring towards the outer cylinder portion 30.

[0023] In the configuration where the outer cylinder 30 covers the valve stem 20, the spring 22 applies a certain spring force toward the contact position between the round cover 26 and the conical part 31.

[0024] The other end face of the large-diameter portion 25 is configured to extend radially relative to the long axis of the shaft portion 21. In other words, the surface direction of the other end face of the large-diameter portion 25 is perpendicular to the spring-pushing direction.

[0025] Furthermore, a bearing 50 is mounted on the spring portion 22. For example, a ball bearing is used for the bearing 50. The bearing 50 is mounted on the other end face of the large-diameter portion 25. Additionally, the surfaces opposite to the mounting surfaces of the spring portion 22 and the bearing 50 are provided with a fixing member 60 to fix the bearing 50 within the valve stem 20, thereby restricting the movement of the spring portion 22 and the bearing 50 in the springing direction.

[0026] The fixing member 60 is fixed to the circumferential surface of the outer cylinder portion 30, restricting the movement of the member disposed at the other end of the large-diameter portion 25 in the spring-push direction. Furthermore, the fixing member 60 maintains the spring-push force from the spring portion 22 on the contact area between the dome portion 26 and the tapered portion 31, both when the shaft portion 21 is stationary and before and after rotation. For example, a C-ring is used for the fixing member 60. A rod-shaped member 61 with a long axis is disposed near the fixing member 60.

[0027] The rod-shaped member 61 has a rod-shaped portion 62 extending perpendicularly to the long axis of the shaft portion 21. One end of the rod-shaped portion 62 is connected to the circumferential surface of the shaft portion 21, and the other end of the rod-shaped portion 62 is provided with a locking member 64. The locking member 64 is slidably fitted into a second recess 63 formed on the inner circumferential surface of the outer cylinder portion 30.

[0028] The elastomer 23 is placed in the first recess 27 formed on the circumferential surface of the large-diameter portion 25. For example, the elastomer 23 is one or more rubber materials. When using one elastomer 23, an O-ring is used to fit into the first recess 27. When using multiple elastomers 23, the elastomers 23 have a spherical or cuboid shape and are arranged to fill the first recess 27 without gaps to ensure a sealing function. Furthermore, the diameter of the elastomer 23 is longer than the depth of the first recess 27. In this way, a sealing function can be effectively achieved. Furthermore, from the viewpoint of not diminishing the sealing function of the housed elastomer 23, the ratio of the diameter of the elastomer 23 to the width of the first recess 27 can be set to a range of 1:1.1 or more and 1:5 or less.

[0029] The outer cylinder portion 30 is a metal component that covers the valve stem 20. The outer cylinder portion 30 covers the shaft portion 21, the spring portion 22, and the elastic body 23. Furthermore, the outer cylinder portion 30 has a tapered portion 31 formed along the curved surface of the dome portion 26. Furthermore, the outer cylinder portion 30 is in contact with at least the large-diameter portion 25 of the shaft portion 21 and the dome portion 26. Furthermore, as described above, a second recess 63 is formed on the inner circumferential surface of the outer cylinder portion 30 for engagement with the aforementioned engaging member 64 located at the other end of the rod-shaped portion 62. The width of the second recess 63 is greater than or equal to the diameter of the engaging member 64. Furthermore, the second recess 63 formed on the inner circumferential surface of the outer cylinder portion 30 is formed continuously in a ring shape on the inner circumferential surface of the outer cylinder portion 30.

[0030] Here, as described above, the diameter of the elastomer 23 is a length greater than or equal to the depth of the first recess 27. Therefore, in the configuration where the outer cylinder 30 covers the valve stem 20, the inner circumferential surface of the outer cylinder 30 is in contact with the elastomer 23.

[0031] In the configuration where the outer cylinder 30 covers the valve stem 20, the conical portion 31 is the part of the outer cylinder 30 that faces the hemispherical curved portion of the dome 26, and it is formed in a conical shape. Since the conical portion 31 is formed in a conical shape and the dome 26 is hemispherical, a part of the conical portion 31 contacts a part of the hemispherical curved portion of the dome 26, thereby making the two in line contact.

[0032] The taper angle (θ) of the tapered portion 31 is preferably 20° or more but not more than 180°. From the viewpoint of achieving the sealing function and avoiding the obstruction of smooth rotation due to the excessive tightness of the components when the shaft portion 21 rotates, it is preferable to have a taper angle of 30° or more but not more than 180°.

[0033] Next, the valve 1 having the sealing mechanism 10 of this embodiment will be described. As shown in FIG1, the valve 1 of this embodiment includes: the sealing mechanism 10 described above; a ball 70 having a hole and connected to the valve stem 20; and a ball seat 71 that holds the ball 70.

[0034] The ball 70 is connected to the valve stem 20 and is a spherical member with a through hole. The valve stem 20 is connected to the surface of the ball 70 in a direction perpendicular to the opening direction of the through hole formed by the ball 70.

[0035] The ball seat 71 is a ring-shaped component made of elastic material, which clamps the ball 70 with appropriate clamping force.

[0036] In the valve 1 of this embodiment using a ball valve, a floating structure or a pivot structure may be appropriately used as the means of supporting the ball 70, depending on the circumstances.

[0037] Next, the operation of valve 1 will be explained.

[0038] First, the outer cylinder 30 covers the valve stem 20, and one end of the shaft 21 is connected to the ball 70. The other end of the shaft 21 (shaft 24) is connected to the handle 40.

[0039] At this time, when fluid can flow through the through hole of the ball 70 (i.e., when valve 1 is open) and when fluid cannot flow through the through hole of the ball 70 (i.e., when valve 1 is closed), the round cap portion 26 and the conical portion 31 of the outer cylinder portion 30 are in metal-to-metal contact (line contact). At this time, even if a foreign object passes through the metal-to-metal contact portion, further movement of the foreign object can be prevented at the contact position between the elastic body 23 and the outer cylinder portion 30.

[0040] When fluid cannot flow through the through hole of the ball 70 (i.e., when valve 1 is completely closed) and when fluid can flow through the through hole of the ball 70 (i.e., when valve 1 is open), even if the handle part 40 is rotated, the spring force is applied from the spring part 22 to the outer cylinder part 30, so the sealing function of the contact position between the conical part 31 and the round cover part 26 can be stably maintained.

[0041] At the same time, the elastic deformation of the elastic body 23 placed on the first recess 27 formed on the circumferential surface of the large diameter portion 25 also achieves the sealing function of the contact position between the elastic body 23 and the outer cylinder portion 30.

[0042] Furthermore, even if the handle 40 is rotated repeatedly, the fluid can still be properly controlled while maintaining the sealing function.

[0043] The sealing mechanism 10 of this embodiment, configured as described above, includes: a shaft portion 21 having a shaft portion 24; a large-diameter portion 25 having a diameter larger than that of the shaft portion 24; a dome portion 26 disposed at one end of the large-diameter portion 25 and on the circumferential surface of the shaft portion 24; a spring portion 22 disposed at the other end of the large-diameter portion 25; an elastic body 23 placed on a first recess 27 formed on the circumferential surface of the large-diameter portion 25; and an outer cylinder portion covering the shaft portion 21, the spring portion 22, and the elastic body 23, having a tapered portion 31 formed along the curved surface of the dome portion 26, and contacting at least the large-diameter portion 25 of the shaft portion 21 and the dome portion 26. More specifically, in the prior art, since a larger space is filled with various components, the number of parts increases. Furthermore, since the sealing function is expected to be achieved through the elastic deformation of the gasket material, elastic deformation needs to be considered in the design, making the design of manufacturing tolerances more complex. In contrast, the sealing mechanism 10 of this embodiment, by having the above-described configuration, concentrates the spring force at the contact position between the round cover portion 26 and the conical portion 31, and makes the spring force from the spring portion 22 continuously act, thereby performing the sealing function. Therefore, the sealing function caused by the shape of the sealing mechanism 10 can be performed, and the sealing function can be performed more efficiently without considering the elasticity of the components.

[0044] Furthermore, in the sealing mechanism 10 of this embodiment, as described above, the taper angle of the tapered portion 31 can be an angle of 30° or more but less than 180°. In this case, a sealing function can be achieved, while preventing the shaft portion 21 from rotating due to excessive tight engagement between the components, which would hinder smooth rotation.

[0045] Furthermore, in the sealing mechanism 10 of this embodiment, as described above, a bearing 50 mounted on the spring portion 22 and a fixing member 60 for fixing the bearing 50 can be included. In this case, the fixed state of the shaft portion 21 can be ensured, while a certain amount of spring force can be efficiently and continuously transmitted to the round cover portion 26 and the conical portion 31.

[0046] Furthermore, in the sealing mechanism 10 of this embodiment, as described above, the elastomer 23 can be an O-ring. In this case, the elastomer 23 can be effectively used in the first recess 27 formed in the large-diameter portion 25.

[0047] Furthermore, in the sealing mechanism 10 of this embodiment, as described above, the other end face of the large-diameter portion 25 can extend radially relative to the long axis of the shaft portion 21. In this case, the surface direction of the other end face of the large-diameter portion 25 becomes perpendicular to the spring-thrust direction, thus the spring-thrust force can be transmitted to the dome portion 26 and the conical portion 31 more efficiently.

[0048] Furthermore, in the sealing mechanism 10 of this embodiment, as described above, the inner circumferential surface of the outer cylinder portion 30 can contact the elastomer 23. In this case, even at the contact position between the elastomer 23 and the outer cylinder portion 30 near the dome portion 26 and the conical portion 31, the sealing function can be achieved, thereby achieving the sealing function more efficiently.

[0049] Furthermore, the valve 1 in this embodiment is equipped with the aforementioned sealing mechanism 10. In this case, the valve 1 can achieve a sealing function using the aforementioned sealing mechanism 10.

[0050] Here, the sealing mechanism 10 of this embodiment is not limited to the above-described form and can be modified in various ways.

[0051] This embodiment is illustrated using the example of the sealing mechanism 10 being applied to the valve 1, but its application is not limited to this. For example, the sealing mechanism 10 can also be applied to the rotary joint 100.

[0052] The rotary joint 100 is equipped with a sealing mechanism 10. As shown in FIG2, the sealing mechanism 10 applied to the rotary joint 100 uses a coil spring as the spring part 22. Furthermore, one end of the spring part 22 (on the side of the dome part 26) is mounted on a component (bearing 50) mounted on the other end face of the large diameter part 25, and a spring force can be applied to the other end via the bearing 50. In addition, a bearing 50 is also mounted on the other end of the spring part 22. In this way, the spring part 22 is clamped by the two bearings 50.

[0053] Furthermore, this embodiment is illustrated using the example of the sealing mechanism 10 being applied to a ball valve and a rotary joint 100. However, if the sealing mechanism 10 can be applied, it can also be applied to other valve mechanisms and joints.

[0054] 1: Valve 10: Sealing mechanism 20: Valve stem 21: Shaft section 22: Spring section 23: Elastomers 24: Shaft 25:Large diameter part 26: Round cap 27: First concave part 30:Outer cylinder part 31: Conical part 40: handle part 50: Bearing 60: Fixed components 61: Rod-shaped component 62: Rod-shaped part 63:Second recess 64: Engaging components 70: Sphere 71: Ball seat 100: Rotary joint

Claims

1. A sealing mechanism comprising: a shaft portion having: a shaft portion; a large-diameter portion having a diameter larger than that of the shaft portion; and a dome portion disposed at one end of the large-diameter portion and on the circumferential surface of the shaft portion; a spring portion disposed at the other end of the large-diameter portion; an elastic body disposed on a recess formed on the circumferential surface of the large-diameter portion; and an outer cylinder portion covering the shaft portion, the spring portion, and the elastic body, having a tapered portion formed along the curved surface of the dome portion, and contacting at least the large-diameter portion and the dome portion of the shaft portion, thereby achieving a sealing function through the line contact between the tapered portion and the dome portion, and achieving an additional sealing function between the elastic body and the outer cylinder portion, thereby preventing further movement of foreign matter at the contact position between the elastic body and the outer cylinder portion even if foreign matter passes through the line contact portion.

2. The sealing mechanism as described in claim 1, wherein, The aforementioned conical angle is an angle of 30° or more but less than 180°.

3. The sealing mechanism as described in claim 1 comprises: a bearing mounted on the aforementioned spring portion; and a fixing member for fixing the aforementioned bearing.

4. The sealing mechanism as described in claim 1, wherein, The aforementioned elastic system O-ring.

5. The sealing mechanism as described in claim 1, wherein, The other end face of the aforementioned large-diameter portion extends radially relative to the long axis of the aforementioned shaft portion.

6. The sealing mechanism as described in claim 1, wherein, The inner circumferential surface of the aforementioned outer cylinder is in contact with the aforementioned elastomer.

7. A valve having the sealing mechanism described in claim 1.

8. A rotary joint having the sealing mechanism described in claim 1.

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