The present disclosure relates to a technique for reducing gas leakage through a rotating shaft.
The following Patent Document 1 discloses a shaft sealing device that inhibits gas leakage by providing a surface contact between a member provided to a shaft and a member provided in a side at an exhaust pipe.
Patent Document 1: Japanese Patent No. 5345708
However, the aforementioned shaft sealing device brings the members in contact with each other by the surface contact, which results in difficulty to provide an even contact between the members and thereby to reduce gas leakage.
In one aspect of the present disclosure, it is desirable to surely enable the shaft sealing device to reduce gas leakage that occurs through the rotating shaft.
The shaft sealing device according to one aspect of the present disclosure comprises a flow passage pipe, a rotating portion, a valve, a shaft seal, and a flow passage seal.
The flow passage pipe comprises a gas flow passage therein, and a through hole that communicates the flow passage with an exterior of the flow passage. The rotating portion is inserted into and held in the through hole, and rotates about a rotation axis that is preset. The valve opens and closes at least one portion of the flow passage in accordance with rotation of the rotating portion. The shaft seal is arranged along an outer circumference of the rotating portion and protrudes therefrom. The flow passage seal is arranged between the flow passage pipe and the rotating portion and surrounds the rotating portion to have a linear contact with respect to the shaft seal.
The shaft sealing device as mentioned above provides the linear contact between the shaft seal and the flow passage seal, enabling the shaft seal and the flow passage seal to easily, more evenly come in contact with each other, than in the case of providing a surface contact therebetween. Thus, the shaft sealing device enables reduction in gas leakage from the flow passage to the exterior of the flow passage.
In addition, the shaft sealing device according to one aspect of the present disclosure may comprise a biasing member that is configured to bias the shaft seal against the flow passage seal.
The shaft sealing device as mentioned above enables biasing of the shaft seal against the flow passage seal, thereby enabling increase in contact pressure between the shaft seal and the flow passage seal. Thus, the shaft sealing device enables reduction in the gas leakage from the flow passage seal to the exterior of the flow passage.
In the shaft sealing device according to one aspect of the present disclosure, the biasing member may bias the shaft seal against the flow passage seal and hold the valve in a preset position.
The shaft sealing device as mentioned above enables the biasing member to function to bias the shaft seal against the flow passage seal and to hold the valve in the preset position, thereby requiring less space in comparison with providing the biasing member for every function.
In the shaft sealing device according to one aspect of the present disclosure, when a virtual plane of the shaft sealing device crosses the shaft sealing device along the rotation axis, one of the shaft seal and the flow passage seal may be configured to form a straight line in a contact portion between the shaft seal and the flow passage seal, whereas the other of the shaft seal and the flow passage seal may be configured to form a curved line in the contact portion between the shaft seal and the flow passage seal.
The shaft sealing device as mentioned above ensures that the shaft seal and the flow passage seal enable the linear contact with each other.
In the shaft sealing device according to one aspect of the present disclosure, when the virtual plane of the shaft sealing device crosses the shaft sealing device along the rotation axis, the contact portion in the shaft seal and the contact portion in the flow passage seal may be configured to form respective curved lines.
The shaft sealing device as mentioned above ensures that the shaft seal and the flow passage seal enables the linear contact with each other.
In the shaft sealing device according to one aspect of the present disclosure, when the virtual plane of the shaft sealing device crosses the shaft sealing device along the rotation axis, the shaft seal and the flow passage seal may comprise contact portions that are positioned in opposing sides across the rotating portion. The shaft seal may bear in respective contact portions respective forces that direct toward the rotation axis or respective forces that direct oppositely with respect to the rotation axis.
The shaft sealing device as mentioned above can function to hold the rotating portion in the fixed position, which enables the flow passage seal to function as a shaft bearing for holding the rotating portion.
1 . . . shaft sealing device, 2 . . . flow passage pipe, 3 . . . gas flow passage, 4 . . . through hole, 6 . . . valve seat, 10 . . . valve, 12 . . . valve body, 14 . . . rotating portion, 14A . . . leading end, 14B, 14C, 14D, 14E . . . shaft seal, 14F . . . protrusion, 16 . . . first hollow cylindrical portion, 16B, 16C, 16D, 16E . . . flow passage seal, 17 . . . contact portion, 18 . . . second hollow cylindrical portion, 20 . . . valve opening and closing mechanism, 22 . . . engaged member, 22A . . . locking hole, 24 . . . biasing member, 26 . . . holding portion.
Hereinafter, an example embodiment of the present disclosure will be described with reference to the drawings.
[1-1. Configuration]
A shaft sealing device 1 shown in
As shown in
As shown in
The valve body 12 opens and closes at least one portion of the gas flow passage 3 and displaces itself in accordance with rotation of the rotating portion 14. The valve body 12 is displaced between a valve closed position where the valve body 12 is in contact with a valve seat 6 that is arranged inside the flow passage pipe 2 and a valve opened position where the valve body 12 is located away from the valve seat 6. In
The rotating portion 14 is a solid cylindrical member that is inserted into and held in the through hole 4, and rotates about a preset rotation axis 21.
As shown in
As shown in
The second hollow cylindrical portion 18 functions as a shaft bearing that rotatably holds the rotating portion 14. Accordingly, as shown in
The blocking member 32 blocks one end of the second hollow cylindrical portion 18 that is opposite to the first hollow cylindrical portion 16. Specifically, the blocking member 32 has the outer diameter that substantially corresponds to the inner diameter of the second hollow cylindrical portion 18, and is fixed to the second hollow cylindrical portion 18 with at least a portion of the blocking member 32 being inserted into the second hollow cylindrical portion 18.
The shaft support 34 is arranged along an outer circumference of the rotating portion 14 and configured as a known shaft bearing that rotatably supports the rotating portion 14. The shaft support 34 can comprise any configurations such as a known bearing and the like.
The shaft seat 36 is fixed to the blocking member 32 and coaxially arranged with the rotation axis 21 of the rotating portion 14. The shaft seat 36 includes, for example, a metal material that is polished to reduce friction and is in contact with an end in the rotating portion 14 that is closer to the blocking member 32 to thereby inhibits the rotating portion 14 from moving toward the blocking member 32. In a configuration where the shaft sealing device 1 comprises a biasing member 24, since the rotating portion 14 is biased in a direction departing from the blocking member 32, the shaft seat 36 may not be included. On the other hand, in a configuration where the shaft sealing device 1 does not comprise the biasing member 24, there is an increasing possibility that the rotating portion 14 may move in any directions along the rotation axis 21. Thus, it is desirable to provide the shaft seat 36.
The flow passage pipe 2 is configured to position the through hole 4 to enable rotation of the rotating portion 14 externally of the flow passage pipe 2. Consequently, this requires an effort to reduce the gas, which flows through the flow passage pipe 2, to leak through a gap between the first hollow cylindrical portion 16 and the rotating portion 14. According to the present embodiment, as shown in
The flow passage seal 16B is arranged in the flow passage pipe 2 and surrounds the rotating portion 14 to have a linear contact with the shaft seal 14B at a contact portion 17. The contact portion 17 refers to a contact portion between the flow passage seal 16B and the shaft seal 14B. The contact portion 17 is configured to have a circular or an oval shape.
As shown in
As shown in
As shown in
The engaged member 22 includes a locking hole 22A formed therein. The locking hole 22A receives a leading end 14A of the rotating portion 14, which is a valve stem, and locks the leading end 14A. The engaged member 22 is rotated by a driving device, such as a motor, a thermal actuator, and the like, that is arranged outside the flow passage pipe 2 to thereby rotate the rotating portion 14 and operate the valve body 12.
The holding portion 26 includes a metal material and holds an end of the biasing member 24 on the valve 10-side to inhibit displacement of the valve 10-side end of the biasing member 24.
The biasing member 24 is configured, for example, as a torsion coil spring. In the valve 10-side end, the biasing member 24 is held in the holding portion 26, whereas in the opposite end, the biasing member 24 is coupled to the engaged member 22. Further, the end of the biasing member 24, which is coupled to the engaged member 22, is displaced in accordance with the rotation of the engaged member 22. According to such configuration, when the valve body 12 is displaced from a preset position, the biasing member 24 biases the valve body 12 to return to the preset position.
Consequently, the biasing member 24 acts to hold the valve body 12 of the valve 10 in the preset position. Note that the preset position refers to, for example, an opened position of the valve body 12, a closed position of the valve body 12, and the like. Particularly, in the present embodiment, the biasing member 24 is attached so as to bias the valve body 12 in a valve closing direction of the valve body 12.
As shown in
[1-2. Effect]
According to the first embodiment detailed above, the following effect can be obtained.
(1a) The aforementioned shaft sealing device 1 comprises the flow passage pipe 2, the rotating portion 14, the valve 10, the shaft seal 14B, and the flow passage seal 16B.
The flow passage pipe 2 forms the gas flow passage 3 therein for gas and provides the through hole 4 that communicates the interior of the gas flow passage 3 with the exterior of the flow passage 3. The rotating portion 14 is inserted into and held in the through hole 4, and rotates about the preset rotation axis 21. The valve 10 opens and closes the at least one portion of the gas flow passage 3 in accordance with the rotation of the rotating portion 14. The shaft seal 14B is arranged along the outer circumference of the rotating portion 14 and protrudes therefrom. The flow passage seal 16B is arranged between the flow passage pipe 2 and the rotating portion 14, and surrounds the rotating portion 14 to have the linear contact with respect to the shaft seal 14B.
The shaft sealing device 1 as mentioned above provides the linear contact between the shaft seal 14B and the flow passage seal 16B, thereby enabling the shaft seal 14B and the flow passage seal 16B to easily, more evenly come in contact with each other, than in the case of providing a surface contact therebetween. Thus, the shaft sealing device 1 enables reduction in gas leakage from the gas flow passage 3 to the exterior of the gas flow passage 3. In addition, since the shaft sealing device 1 provides the linear contact between the shaft seal 14B and the flow passage seal 16B, this enables reduction in fractional resistance occurred in displacement of the valve 10, in comparison with the case of providing a surface contact therebetween.
(1b) The aforementioned shaft sealing device 1 comprises the biasing member 24 that is configured to bias the shaft seal 14B against the flow passage seal 16B.
The shaft sealing device 1 as mentioned above enables biasing of the shaft seal 14B against the flow passage seal 16B, thereby enabling increase in contact pressure between the shaft seal 14B and the flow passage seal 16B. Thus, the shaft sealing device 1 enables reduction in the gas leakage from the gas flow passage 3 to the exterior of the gas flow passage 3.
(1c) In the aforementioned shaft sealing device 1, the biasing member 24 biases the shaft seal 14B against the flow passage seal 16B and holds the valve 10 in the preset position.
The shaft sealing device 1 as mentioned above enables the biasing member 24 to function to bias the shaft seal 14B against the flow passage seal 16B and to hold the valve 10 in the preset position, thereby requiring less space in comparison with the case of providing the biasing member 24 for every function. In addition, the shaft sealing device 1 also enables reduction in the number of parts, which results in cost reduction, in comparison with the case of providing the biasing member 24 for every function.
(1d) In the aforementioned shaft sealing device 1, when the virtual plane of the shaft sealing device 1 crosses thereof along the rotation axis 21, one of the shaft seal 14B and the flow passage seal 16B is configured to form a straight line in the contact portion 17 between the shaft seal 14B and the flow passage seal 16B, whereas the other of the shaft seal 14B and the flow passage seal 16B is configured to form a curved line in the contact portion 17 between the shaft seal 14B and the flow passage seal 16B.
The shaft sealing device 1 as mentioned above provides, as viewed in a section, a point contact between the straight line and the curved line, thereby ensuring that the shaft seal 14B and the flow passage seal 16B enable the linear contact with each other.
(1e) In the aforementioned shaft sealing device 1, when the virtual plane of the shaft sealing device 1 crosses thereof along the rotation axis 21, the shaft seal 14B and the flow passage seal 16B comprise contact portions that are positioned in the opposing sides across the rotating portion 14. The shaft seal 14B bears in the respective contact portions respective forces that direct toward the rotation axis 21 or respective forces that direct oppositely with respect to the rotation axis 21.
The shaft sealing device 1 as mentioned above can function to hold the rotating portion 14 in the fixed position. Accordingly, this enables the flow passage seal 16B to function as the shaft bearing for holding the rotating portion 14.
Accordingly, while the embodiments of the present disclosure have been described, the present disclosure is not limited to the above-described embodiments and can be implemented in various modifications.
(2a) According to the aforementioned embodiments, when the appropriately selected virtual plane of the shaft sealing device crosses thereof along the rotation axis 21 of the rotating portion 14, the shaft seal 14B is configured to form the linear contact portion in the shaft seal 14B with the flow passage seal 16B, whereas the flow passage seal 16B is configured to form the curved contact portion in the flow passage seal 16B with the shaft seal 14B. However, the configurations of the shaft seal and the flow passage seal are not limited hereto. For example, as shown in
(2b) According to the aforementioned embodiment, when the virtual plane of the shaft sealing device 1 crosses thereof along the rotation axis 21 of the rotating portion 14, the shaft seal 14B is configured to bear in the respective contact portions 17 the respective forces that direct oppositely with respect to the rotation axis 21 of the rotating portion 14. However, the shaft seal 14B may be configured to bear in the respective contact portions 17 respective forces that direct toward the rotation axis 21.
That is, as shown in
(2c) Further, the flow passage seal and the shaft seal 14B can have appropriately selected respective configurations that can surround the rotating portion 14 to have the linear contact with each other. For example, as shown in
(2d) According to the aforementioned embodiment, the flow passage pipe 2 is configured to flow the exhaust gas therethrough. However, the flow passage pipe 2 may be configured to flow gas other than the exhaust gas therethrough.
The same effect as the effect of (1a) can be obtained according to the aforementioned (2a) to (2d).
(2e) Functions of one element of the aforementioned embodiment may be distributed to plurality of elements. Functions of a plurality of elements may be integrated into one element. Part of the configurations of the above-described embodiments may be omitted. At least part of the configurations of the above-described embodiments may be added to or replaced with the configurations of the other above-described embodiments. Any embodiment included in the technical ideas defined by the language of the claims is an embodiment of the present disclosure.
(2f) The present disclosure can be realized in various modes other than the aforementioned shaft sealing device, such as a system comprising the shaft sealing device as a component, a shaft sealing method, and the like.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2016/054336 | 2/15/2016 | WO | 00 |