Seal mechanisms, valves, and rotary joints

Abstract

To provide a seal mechanism, a valve and a rotary joint that are capable of exhibiting a sealing function with a simple configuration.SOLUTION: A seal mechanism 10 is provided with: a shaft 21 having an axial part 24, a large-diameter part 25 having a larger diameter than the axial part 24, and a circular lid 26 provided on one end of the large-diameter part 25 and a peripheral surface of the axial part 24; a spring 22 disposed at the other end of the large-diameter part 25; an elastic body 23 placed on a recess (first recess 27) formed on a peripheral surface of the large-diameter part 25; and an outer cylinder portion 30 that encloses the shaft 21, the spring 22, and the elastic body 23, has a tapered part 31 formed along a curved surface of the circular lid 26, and is in contact with at least the large-diameter part 25 and the circular lid 26 of the shaft 21.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a sealing mechanism, a valve, and a rotary joint.

Background Art

[0002] Conventionally, various valves for controlling the flow of fluid in piping have been known. For example, the technique of Patent Document 1 discloses a shaft sealing device that is particularly applicable to a ball valve that is opened and closed by the rotation of a valve body accompanying a handle operation.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the ball valve in Patent Document 1, since a relatively large space is filled with various members, the number of parts increases. Further, since it is expected to have a sealing function due to the elastic deformation of the packing material, a design considering elastic deformation is required, and the design of manufacturing tolerances also becomes complicated.

[0005] The present disclosure has been made in consideration of such points, and an object thereof is to provide a sealing mechanism, a valve, and a rotary joint that can exhibit a sealing function with a simple configuration.

Means for Solving the Problems

[0006] The sealing mechanism of the present disclosure is a shaft portion having a shaft portion, a large-diameter portion having a larger diameter than the shaft portion, and a lid portion provided on one end of the large-diameter portion and the circumferential surface of the shaft portion, a spring portion disposed at the other end of the large-diameter portion, and an elastic body placed in a recess formed on the circumferential surface of the large-diameter portion. The device comprises an outer cylinder portion that encloses the shaft portion, the spring portion, and the elastic body, and has a tapered portion formed along the curved surface of the dome portion, and at least the large diameter portion of the shaft portion and the outer cylinder portion that is in contact with the dome portion.

[0007] In the sealing mechanism of this disclosure, The taper angle of the tapered portion may be in the range of 30° or more and less than 180°.

[0008] In the sealing mechanism of this disclosure, A bearing placed on the spring portion, The system may also include a fixing member for fixing the bearing.

[0009] In the sealing mechanism of this disclosure, The elastic body may be an O-ring.

[0010] In the sealing mechanism of this disclosure, The other end face of the large-diameter portion may extend radially with respect to the longitudinal axis of the shaft portion.

[0011] In the sealing mechanism of this disclosure, The inner circumferential surface of the outer cylinder portion may be in contact with the elastic body.

[0012] The valves in this disclosure are The device is equipped with the aforementioned sealing mechanism.

[0013] The rotary joint of this disclosure is The device is equipped with the aforementioned sealing mechanism. [Effects of the Invention]

[0014] The sealing mechanism, valve, and rotary joint of this disclosure can provide a sealing function with a simple configuration. [Brief explanation of the drawing]

[0015] [Figure 1]It is a schematic diagram showing the configuration of the valve according to this embodiment. [Figure 2] It is a diagram showing a modification according to this embodiment, and is a schematic diagram showing the configuration of a rotary joint provided with the seal mechanism according to this embodiment.

Embodiments for Carrying out the Invention

[0016] Hereinafter, the seal mechanism 10 and the valve 1 according to this embodiment will be described by way of example and reference to the drawings. FIGS. 1 and 2 are diagrams showing the seal mechanism 10 and the valve 1 according to this embodiment. Among these, FIG. 1 is a schematic diagram showing the configuration of the valve 1 according to this embodiment. FIG. 2 is a diagram showing a modification according to this embodiment, and is a schematic diagram showing the configuration of a rotary joint 100 provided with the seal mechanism 10 according to this embodiment.

[0017] First, the seal mechanism 10 according to this embodiment will be described. As shown in FIG. 1, the seal mechanism 10 according to this embodiment includes a stem 20 including a shaft portion 21 and an outer cylinder portion 30 that encloses the stem 20. In this specification, a ball valve is exemplified and described as the valve 1.

[0018] The stem 20 includes a shaft portion 21, a spring portion 22 that biases the ball 70, and an elastic body 23 attached to the peripheral surface of the shaft portion 21, and is a member that rotates the ball 70 by rotating about the axis.

[0019] The shaft portion 21 has a shaft portion 24 that is a rod-shaped or cylindrical base shaft having a longitudinal axis, a large-diameter portion 25 that has a larger diameter than the shaft portion 24 and constitutes a part of the shaft portion 24, and a hemispherical dome portion 26 provided from one end of the large-diameter portion 25 toward the peripheral surface of the shaft portion 24.

[0020] The shaft portion 24 is a rod-shaped or cylindrical metal component. One end of the shaft portion 24 is connected to a ball 70, and power is transmitted to the ball 70 by rotational motion. The other end of the shaft portion 24 is connected to a handle portion 40, and the shaft portion 24 is rotated by rotating the handle portion 40 in the forward or reverse direction.

[0021] The large-diameter portion 25 is the enlarged part of the shaft portion 24 and occupies a continuous area on the shaft portion 24. On the shaft portion 24, the large-diameter portion 25 is located from the center of the shaft portion 24 toward one end. The diameter of the large-diameter portion 25 can be in the range of 1.5 times or more and 2.5 times or less the diameter of the shaft portion 24. If 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 relatively small, which reduces its practicality from the standpoint of manufacturing tolerances when commercializing the product. Also, if the diameter of the large-diameter portion 25 exceeds 2.5 times the diameter of the shaft portion 24, the size may become excessively large when commercializing the product. Furthermore, the ratio of the length in the longitudinal axis direction of the large-diameter portion 25 and the shaft portion 24 can be in the range of 1:3 to 1:10 in order to ensure its function as a shaft.

[0022] Furthermore, a first recess 27 is formed on the circumferential surface of the large-diameter portion 25. The first recess 27 is a depression formed in the circumferential direction on the circumferential surface of the large-diameter portion 25 and is formed endlessly. The ratio of the depth to the width of the first recess 27 can be in the range of 1:1.1 to 1:3, from the viewpoint of not attenuating the function of the contained elastic body 23.

[0023] The dome portion 26 is a hemispherical portion provided from one end of the large-diameter portion 25 toward the circumferential surface of the shaft portion 24. The central axes of the dome portion 26 and the shaft portion 24 overlap. Furthermore, the size of the hemispherical surface of the dome portion 26 is changed by a curvature corresponding to the sizes of the shaft portion 24 and the large-diameter portion 25.

[0024] The spring portion 22 is a mechanical element positioned at the other end of the large-diameter portion 25. For example, it is one or more members that can bias the other end via a member placed on the other end face of the large-diameter portion 25 or a member placed on the other end face of the large-diameter portion 25, and is a member that can bias the outer cylinder portion 30. For example, a leaf spring is used as the spring portion 22. The length of the spring portion 22 positioned at the other end of the large-diameter portion 25 in the direction perpendicular to the biasing 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, the spring portion 22 is positioned along the circumferential surface of the other end of the large-diameter portion 25 in order to bias evenly toward the outer cylinder portion 30. When using multiple spring portions 22, the spring portions 22 are positioned at equal intervals on the circumferential surface of the other end of the large-diameter portion 25 in order to bias evenly toward the outer cylinder portion 30.

[0025] In the configuration in which the stem 20 is enclosed within the outer cylinder portion 30, the spring portion 22 exerts a constant biasing force toward the contact point between the cap portion 26 and the tapered portion 31.

[0026] The other end face of the large-diameter portion 25 extends radially with respect to the longitudinal 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 biasing direction.

[0027] Furthermore, a bearing 50 is mounted on the spring portion 22. For example, a ball bearing is used as the bearing 50. The bearing 50 is mounted on the other end face of the large diameter portion 25. In addition, on the opposite side of the mounting surface of the spring portion 22 and the bearing 50, a fixing member 60 is provided to fix the bearing 50 inside the stem 20 in order to restrict the movement of the spring portion 22 and the bearing 50 in the biasing direction.

[0028] The fixing member 60 is fixed to the circumferential surface of the outer cylinder portion 30 and is a member that restricts the movement of the member positioned at the other end of the large-diameter portion 25 in the biasing direction. In addition, the fixing member 60 is a member that maintains the biasing force from the spring portion 22 on the contact points of the cap 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 can be used as the fixing member 60. A rod-shaped member 61 having a longitudinal axis is positioned near the fixing member 60.

[0029] The rod-shaped member 61 has a rod-shaped portion 62 that extends perpendicularly to the longitudinal 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.

[0030] The elastic body 23 is a component placed in the first recess 27 formed on the circumferential surface of the large-diameter portion 25. For example, the elastic body 23 is one or more rubber materials. When one elastic body 23 is used, an O-ring is used and fitted into the first recess 27. When multiple elastic bodies 23 are used, the elastic bodies 23 have a spherical or rectangular parallelepiped shape and are arranged and filled into the first recess 27 without gaps to ensure a sealing function. In addition, the diameter of the elastic body 23 is longer than or equal to the depth of the first recess 27. This allows for an effective sealing function. Furthermore, the ratio of the diameter of the elastic body 23 to the width of the first recess 27 can be in the range of 1:1.1 to 1:5, from the viewpoint of not attenuating the sealing function provided by the contained elastic body 23.

[0031] The outer cylinder portion 30 is a metal member that encloses the stem 20. The outer cylinder portion 30 encloses the shaft portion 21, the spring portion 22, and the elastic body 23. The outer cylinder portion 30 also has a tapered portion 31 formed along the curved surface of the cap portion 26. The outer cylinder portion 30 is in contact with at least the large diameter portion 25 of the shaft portion 21 and the cap portion 26. Furthermore, as described above, a second recess 63 is formed on the inner circumferential surface of the outer cylinder portion 30 into which the locking member 64 provided at the other end of the rod-shaped portion 62 is fitted. The width of the second recess 63 is greater than or equal to the diameter of the locking 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.

[0032] As described above, the diameter of the elastic body 23 is greater than or equal to the depth of the first recess 27. Therefore, in the configuration in which the stem 20 is enclosed by the outer cylinder portion 30, the inner circumferential surface of the outer cylinder portion 30 is in contact with the elastic body 23.

[0033] The tapered portion 31 is a part of the outer cylinder 30 that is positioned opposite the hemispherical curved portion of the dome portion 26 in the configuration in which the stem 20 is enclosed by the outer cylinder 30, and is formed in a tapered shape. Because the tapered portion 31 is formed in a tapered shape and the dome portion 26 is hemispherical, a part of the tapered portion 31 contacts a part of the hemispherical curved portion of the dome portion 26, so that the two are in line contact.

[0034] The taper angle (θ) of the tapered portion 31 is preferably 20° or more and less than 180°, and more preferably 30° or more and less than 180° from the viewpoint of providing a sealing function while avoiding the prevention of smooth rotation due to the interlocking of components when the shaft portion 21 rotates.

[0035] Next, a valve 1 equipped with the sealing mechanism 10 according to this embodiment will be described. As shown in Figure 1, the valve 1 according to this embodiment comprises the sealing mechanism 10 described above, a ball 70 with a hole formed therein and to which the stem 20 is connected, and a ball seat 71 that sandwiches the ball 70.

[0036] The ball 70 is a spherical member to which the stem 20 is connected, and has a through hole formed therein. The stem 20 is connected to the surface of the ball 70 in a direction perpendicular to the opening direction of the through hole formed in the ball 70.

[0037] The ball seat 71 is a ring-shaped member that clamps the ball 70 with an appropriate amount of tension, and is formed of an elastic material.

[0038] In this embodiment of valve 1, which uses a ball valve, a floating structure or a trunnion structure is used as appropriate depending on the situation to support the ball 70.

[0039] Next, we will explain the operation of valve 1 when it is in use.

[0040] First, the stem 20 is enclosed in the outer cylinder 30, and one end of the shaft 21 is connected to the ball 70. The other end of the shaft 21 (axis 24) is connected to the handle 40.

[0041] At this time, when the fluid can move through the through hole of the ball 70 (i.e., when the valve 1 is open) and when the fluid cannot move through the through hole of the ball 70 (i.e., when the valve 1 is closed), the round cover portion 26 and the tapered portion 31 of the outer cylinder portion 30 are in metallic contact (line contact). At this time, even if foreign matter passes through the metallic contact portion, further movement of the foreign matter can be prevented at the contact point between the elastic body 23 and the outer cylinder portion 30.

[0042] In both the state where fluid cannot pass through the through-hole of the ball 70 (i.e., when the valve 1 is fully open) and the state where fluid can pass through the through-hole of the ball 70 (i.e., when the valve 1 is open), the rotation of the handle portion 40 also exerts a biasing force from the spring portion 22 to the outer cylinder portion 30, thus maintaining a constant sealing function at the contact point between the tapered portion 31 and the round cap portion 26.

[0043] At the same time, the elastic deformation of the elastic body 23, which is placed in the first recess 27 formed on the circumferential surface of the large-diameter portion 25, provides a sealing function at the contact point between the elastic body 23 and the outer cylinder portion 30.

[0044] Furthermore, even if the handle portion 40 is rotated repeatedly, the sealing function can be maintained while appropriately controlling the fluid.

[0045] The sealing mechanism 10 according to this embodiment, having the above configuration, comprises a shaft portion 21 having a shaft portion 24, a large-diameter portion 25 with a larger diameter than the shaft portion 24, and a cap portion 26 provided 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 30 that encloses the shaft portion 21, the spring portion 22, and the elastic body 23, has a tapered portion 31 formed along the curved surface of the cap portion 26, and contacts at least the large-diameter portion 25 and the cap portion 26 of the shaft portion 21. To explain in more detail, in the prior art, a relatively large space is filled with various members, resulting in a large number of parts. Also, since the sealing function is expected to be due to the elastic deformation of the packing material, a design that takes elastic deformation into consideration is necessary, and the design of manufacturing tolerances becomes complex. In contrast, the sealing mechanism 10 of this embodiment, by having the above configuration, concentrates the biasing force at the contact point between the rounded cap portion 26 and the tapered portion 31, and continuously applies the biasing force from the spring portion 22 to exert a sealing function. Therefore, the sealing function can be exerted due to the shape of the sealing mechanism 10, and the sealing function can be exerted more efficiently without considering the elasticity of the members.

[0046] Furthermore, in the sealing mechanism 10 of this embodiment, as described above, the taper angle of the tapered portion 31 may be in the range of 30° to less than 180°. In this case, while maintaining the sealing function, it is possible to avoid the prevention of smooth rotation due to the members interlocking when the shaft portion 21 rotates.

[0047] Furthermore, the sealing mechanism 10 of this embodiment may also include a bearing 50 mounted on the spring portion 22 and a fixing member 60 for fixing the bearing 50, as described above. In this case, a constant biasing force can be efficiently transmitted to the cap portion 26 and the tapered portion 31 while ensuring that the shaft portion 21 remains fixed.

[0048] Furthermore, in the sealing mechanism 10 of this embodiment, as described above, the elastic body 23 may be an O-ring. In this case, the elastic body 23 can be effectively applied to the first recess 27 formed in the large-diameter portion 25.

[0049] Furthermore, in the sealing mechanism 10 of this embodiment, as described above, the other end face of the large-diameter portion 25 may extend radially with respect to the longitudinal axis of the shaft portion 21. In this case, the surface direction of the other end face of the large-diameter portion 25 is perpendicular to the biasing direction, so the biasing force can be transmitted more efficiently to the dome portion 26 and the tapered portion 31.

[0050] Furthermore, in the sealing mechanism 10 of this embodiment, as described above, the inner circumferential surface of the outer cylinder portion 30 may be in contact with the elastic body 23. In this case, the sealing function can be exerted even at the contact points between the elastic body 23 and the outer cylinder portion 30 near the cap portion 26 and the tapered portion 31, allowing the sealing function to be exerted more effectively.

[0051] Furthermore, the valve 1 according to this embodiment includes the sealing mechanism 10 described above. In this case, a valve 1 that performs a sealing function by the sealing mechanism 10 described above can be realized.

[0052] Furthermore, the sealing mechanism 10 according to this embodiment is not limited to the above-described configuration, and various modifications can be made.

[0053] In this embodiment, the example described shows the seal mechanism 10 applied to the valve 1, but it is not limited to this configuration. For example, the seal mechanism 10 may be applied to the rotary joint 100.

[0054] The rotary joint 100 is equipped with a sealing mechanism 10. As shown in Figure 2, in the sealing mechanism 10 applied to the rotary joint 100, a spring is used as the spring portion 22. One end of the spring portion 22 (the side facing the rounded cap portion 26) is mounted on a member (bearing 50) that is placed on the other end face of the large-diameter portion 25, and can be biased to the other end via the bearing 50. The other end of the spring portion 22 is also mounted on a bearing 50. As a result, the spring portion 22 is sandwiched between the two bearings 50.

[0055] Furthermore, although this embodiment has described an example in which the sealing mechanism 10 is applied to a ball valve and a rotary joint 100, the sealing mechanism 10 can also be applied to other valve mechanisms and joints as long as it can be applied to them. [Explanation of Symbols]

[0056] 1: Valve 10: Seal mechanism 20: Stem 21: Shaft section 22: Spring part 23: Elastic body 24: Shaft 25: Large diameter section 26: Dome 27: First recess 30: Outer cylinder part 31: Tapered section 40: Handle section 50: Bearings 60: Fixing member 61: Rod-shaped member 62: Rod-shaped part 63: Second recess 64: Locking member 70: Ball 71: Ball Sheet 100: Rotary joint

Claims

1. A shaft portion having a shank portion, a larger diameter portion having a larger diameter than the shank portion, and a rounded cap portion provided at one end of the larger diameter portion and on the circumferential surface of the shank portion, A spring portion is positioned at the other end of the large-diameter portion, An elastic body placed in a recess formed on the circumferential surface of the large-diameter portion, It comprises the shaft portion, the spring portion, and the elastic body, and has a tapered portion formed along the curved surface of the dome portion, and includes at least the large diameter portion of the shaft portion and an outer cylindrical portion that contacts the dome portion, The tapered portion and the cap portion provide a sealing function through line contact, and an additional sealing function is provided between the elastic body and the outer cylinder portion. As a result, even if foreign matter passes through the line contact portion, further movement of the foreign matter can be prevented at the contact point between the elastic body and the outer cylinder portion. Seal mechanism.

2. In the shaft portion, the recess is located between the cap portion and the location where the spring portion is arranged. The sealing mechanism according to claim 1.

3. The bearing placed on the spring portion, The system comprises a fixing member for fixing the bearing, The sealing mechanism according to claim 1.

4. The elastic body is an O-ring. The sealing mechanism according to claim 1.

5. The other end face of the large-diameter portion extends radially with respect to the longitudinal axis of the shaft portion. The sealing mechanism according to claim 1.

6. The inner circumferential surface of the outer cylinder portion is in contact with the elastic body. The sealing mechanism according to claim 1.

7. A sealing mechanism according to any one of claims 1 to 6, valve.

8. A sealing mechanism according to any one of claims 1 to 6, Rotary joint.

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