Shaft seal device

Abstract

Reduces vibrations in rotating machinery. [Solution] A gas bearing 2 is provided to support the rotating shaft 3 so that it can rotate relative to the case C. The gas bearing 2 supports the rotating shaft 3 from the outside in the radial direction R and is positioned at a distance in the axial direction L from the rotation drive source Rs which are connected to the axial base end L1 of the rotating shaft 3 from the mechanical seal 1.

Description

Technical Field

[0001] The present invention relates to a shaft sealing device including a case and a mechanical seal that penetrates into the case and seals around a rotating shaft extending along the axial direction.

Background Art

[0002] Conventionally, shaft sealing devices that seal around a rotating shaft have been used for rotating equipment such as blowers and compressors (see, for example, Patent Document 1). This makes it possible to suppress fluid leakage.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such rotating equipment, vibration due to the rotation of the rotating shaft is inevitable. However, since this vibration may affect the performance of the rotating equipment, it is preferably reduced as much as possible.

[0005] In view of the above situation, a shaft sealing device that can easily reduce the vibration of rotating equipment is desired.

Means for Solving the Problems

[0006] A shaft sealing device including a case and a mechanical seal that penetrates into the case and seals around a rotating shaft extending along the axial direction, a gas bearing is provided to support the rotating shaft so as to be relatively rotatable with respect to the case, The gas bearing supports the rotating shaft from the radially outer side and is positioned at a distance in the axial direction from the rotational drive source, which is connected to the rotating shaft at the axial base end side of the mechanical seal.

[0007] The rotating shaft, an essential element of rotating machinery, is connected to a rotational drive source and rotates by obtaining driving force from this source. When the rotating shaft rotates, some vibration inevitably occurs. With this configuration, since a gas bearing that allows for non-contact support is used to support the rotating shaft, the rotating shaft can be supported with low friction, resulting in a high vibration suppression effect. Furthermore, the vibration generated when the rotating shaft rotates tends to be greater at points further axially away from the axial base end where the rotating shaft is connected by the rotational drive source. With this configuration, since such a gas bearing supports the rotating shaft at a position axially away from the rotational drive source connected to the rotating shaft at the axial base end, it is possible to support the tip end of the rotating shaft where vibrations tend to be greater, and a high vibration suppression effect can be obtained. As described above, this configuration makes it possible to realize a shaft sealing device that can easily reduce vibrations in rotating machinery.

[0008] Further features and advantages of the technology relating to this disclosure will become clearer from the following description of exemplary and non-limiting embodiments, with reference to the drawings. [Brief explanation of the drawing]

[0009] [Figure 1] Cross-sectional view showing the shaft seal device [Figure 2] Cross-sectional view showing gas flow [Figure 3] Cross-sectional view showing a shaft seal device according to another embodiment. [Figure 4] Cross-sectional view showing a shaft seal device according to another embodiment. [Modes for carrying out the invention]

[0010] Shaft seal devices are used in rotating machinery such as blowers and compressors, and their purpose is to seal the area around the rotating shaft to suppress fluid leakage. Embodiments of shaft seal devices will be described below with reference to the drawings.

[0011] In the following, the "axial direction L," "radial direction R," and "circumferential direction" are defined with respect to the axis Ax of the rotation axis 3. Furthermore, one side of the axial direction L is defined as the "axial base end side L1," and the other side as the "axial tip end side L2."

[0012] As shown in Figure 1, the shaft seal device 100 is used in rotating machinery M. Examples of rotating machinery M include blowers and compressors.

[0013] The shaft sealing device 100 comprises a case C and a mechanical seal 1 that penetrates the case C and seals the area around the rotating shaft 3 which extends along the axial direction L.

[0014] Case C is formed in a cylindrical shape. In this embodiment, Case C is constructed by arranging and connecting a plurality of annular members in the axial direction L. However, the case C is not limited to this configuration and may be constructed as a single piece.

[0015] The rotating shaft 3 penetrates the case C at its axial tip end L2 and is connected to the rotational drive source Rs at its axial base end L1. That is, the axial tip end L2 of the rotating shaft 3 is located inside the case C. The axial base end L1 of the rotating shaft 3 is connected and supported by the rotational drive source Rs. Examples of the rotational drive source Rs include electric motors and engines.

[0016] In this embodiment, the rotating shaft 3 comprises a shaft body 30, a sleeve 31 positioned radially R outward from the shaft body 30, and an adapter 32 positioned radially R outward from the sleeve 31.

[0017] The shaft body 30 and the sleeve 31 are connected radially in the R direction via an O-ring 99. Furthermore, the shaft body 30 and the sleeve 31 are fixed to each other by fasteners 97 positioned along the radial direction R. This configuration allows the shaft body 30 and the sleeve 31 to rotate as a single unit.

[0018] The sleeve 31 and the adapter 32 are connected radially in the R direction via an O-ring 98. In this embodiment, a portion of the axial direction L of the sleeve 31 constitutes a flange portion 310 that extends radially in the R direction. The flange portion 310 includes a first opposing wall portion 311 having a surface facing the axial base end side L1, and a second opposing wall portion 312 having a surface facing the axial tip end side L2. In this embodiment, the adapter 32 is positioned to abut against the second opposing wall portion 312 from the axial tip end side L2. On the other hand, an annular retaining plate 320 is positioned on the axial tip end side L2 of the adapter 32. The retaining plate 320 abuts against both the adapter 32 and the sleeve 31 from the axial tip end side L2 and is fastened to the sleeve 31 by bolts. Thus, the axial base end side L1 of the adapter 32 abuts against the first opposing wall portion 311, and the axial tip end side L2 of the adapter 32 abuts against the retaining plate 320.

[0019] In this embodiment, the mechanical seal 1 comprises a rotating ring 12 attached to a rotating shaft 3 and a stationary ring 11 attached to a case C, and is configured to form a sealing surface S by supplying gas between the rotating ring 12 and the stationary ring 11 in the axial direction L. A gas supply source Gs for supplying gas to the sealing surface S is provided outside the case C. In other words, the mechanical seal 1 according to this embodiment is a so-called static pressure type mechanical seal 1, and forms a sealing surface S with a layer of gas supplied from the gas supply source Gs, sealing the space between the rotating ring 12 and the stationary ring 11 without contact. Examples of gas supplied from the gas supply source Gs include inert gases such as nitrogen and compressed air.

[0020] In the present embodiment, the rotating ring 12 is disposed on the outer periphery of the sleeve 31 on the rotating shaft 3. The rotating ring 12 abuts against the above-described first opposing wall portion 311 from the proximal end side L1 in the axial direction. The rotating ring 12 is a mating ring whose position in the axial direction L is fixed. On the surface of the rotating ring 12 facing the proximal end side L1 in the axial direction, a seal end face 12a extending annularly around the axis Ax is formed. The seal end face 12a is finished to a highly accurate flat surface such that the surface roughness is not more than a predetermined set value. For example, by forming the seal end face 12a with a film formed by ceramic spraying, the durability against contact with the fixed ring 11 can be improved.

[0021] In the present embodiment, the fixed ring 11 is disposed on the inner periphery of the case C. The surface of the fixed ring 11 facing the distal end side L2 in the axial direction and the surface of the rotating ring 12 facing the proximal end side L1 in the axial direction face each other in the axial direction L. The fixed ring 11 is a seal ring and is configured to be operable in the axial direction L by being urged by an urging member 11a. Examples of the urging member 11a include a spring and a bellows.

[0022] A gas introduction passage 5 is provided from the gas supply source Gs to the supply target location. In the present embodiment, the gas introduction passage 5 includes a first introduction passage 51 for supplying gas to the seal surface S. The first introduction passage 51 is provided so as to communicate the case C and the fixed ring 11 and opens at the seal surface S. The gas supplied to the seal surface S collides with the seal end face 12a of the rotating ring 12 described above and branches and flows out from the seal end face 12a into a storage space 40 (described later) and an atmospheric side space 41. By this action, a seal surface S composed of a gas layer is formed between the rotating ring 12 and the fixed ring 11 in a non-contact state.

[0023] As described above, the rotating shaft 3 penetrates the case C at its distal end side and is connected to a rotation drive source Rs at its proximal end side. And fluid leakage is suppressed by a mechanical seal 1 provided inside the case C.

[0024] Here, as shown in Figure 1, a gas bearing 2 is provided to support the rotating shaft 3 so that it can rotate relative to the case C. In this embodiment, the gas bearing 2 is configured as a so-called hydrostatic gas bearing 2 that supports the rotating shaft 3 using gas supplied from the outside.

[0025] Thus, since a non-contact gas bearing 2 is used to support the rotating shaft 3, the rotating shaft 3 can be supported with low friction, thereby enhancing the vibration suppression effect. Furthermore, since a hydrostatic type gas bearing 2 is used, a stable and thick lubricating film can be formed compared to a hydrodynamic type, and an even greater vibration suppression effect can be expected.

[0026] The gas bearing 2 supports the rotating shaft 3 from the outside in the radial direction R, and is positioned at a distance L in the axial direction from the rotational drive source Rs, which is connected to the rotating shaft 3 at the axial base end side of the mechanical seal 1. In this embodiment, the gas bearing 2 is positioned L2 on the axial tip side of the mechanical seal 1.

[0027] The vibrations generated when the rotating shaft 3 rotates tend to be greater at the axial tip side L2 than at the axial base side L1 where the rotating shaft 3 is connected by the rotation drive source Rs. With the above configuration, since the gas bearing 2 supports the rotating shaft 3 at the axial tip side L2 rather than where the mechanical seal 1 is located, it can support the tip portion of the rotating shaft 3 where vibrations tend to be greater, and a high vibration suppression effect can be obtained.

[0028] In this embodiment, the gas bearing 2 is positioned radially outward from the adapter 32 in the direction R, and is configured to support the shaft body 30 via the adapter 32 and the sleeve 31. Although the gas bearing 2 supports the object with low friction, deterioration due to wear is unavoidable. With this configuration, since the gas bearing 2 directly supports the adapter 32 rather than the shaft body 30, the effects of deterioration due to wear are borne by the adapter 32. Therefore, during maintenance, there is less need to perform the extensive work of replacing the shaft body 30, and it is possible to do so by replacing only the adapter 32, thereby improving maintainability.

[0029] In this embodiment, the gas bearing 2 is positioned in the axial direction L relative to the case C by a snap ring 20. The snap ring 20 is attached to the inner circumferential surface of the case C and is provided to protrude radially R inward from the inner circumferential surface of the case C. The protruding portion of the snap ring 20 abuts against the gas bearing 2 in the axial direction L. This positions the gas bearing 2 in the axial direction L.

[0030] By using a snap ring 20 to position the gas bearing 2, the design flexibility of the axial dimension of the gas bearing 2 is improved. That is, since the snap ring 20 can be attached to the case C relatively easily, the mounting position of the snap ring 20 on the case C can be flexibly set. Therefore, it becomes possible to design the axial dimension of the gas bearing 2, which is positioned by the snap ring 20, with a high degree of freedom. Considering the interaction with other members inside the case C, the axial dimension of the gas bearing 2 can be designed to be shorter, or conversely, the axial dimension of the gas bearing 2 can be designed to be longer. When the axial dimension of the gas bearing 2 is designed to be longer, the support range in which the rotating shaft 3 can be supported by the gas bearing 2 can be extended in the axial direction L, and the vibration suppression effect of the rotating shaft 3 can be enhanced.

[0031] In this embodiment, the gas supplied to the sealing surface S and the gas supplied to the gas bearing 2 are supplied from the same gas supply source Gs. This simplifies the structure compared to supplying gas separately to the sealing surface S and the gas bearing 2, and allows for efficient use of the gas generated from the gas supply source Gs, thereby making it easier to reduce costs.

[0032] In the above description, the gas introduction passage 5 includes a first introduction passage 51 for supplying gas to the sealing surface S. However, in this embodiment, the gas introduction passage 5 further includes a second introduction passage 52 for supplying gas to the gas bearing 2. The second introduction passage 52 is provided to connect the case C and the gas bearing 2 and opens on the inner circumferential surface of the gas bearing 2 in the radial direction R. In this example, the second introduction passage 52 is provided at multiple locations in the gas bearing 2 so as to penetrate the gas bearing 2 in the radial direction R. The multiple through holes constituting the second introduction passage 52 provided in the gas bearing 2 are arranged at equal intervals along the axial direction L and the circumferential direction. This makes it easier to supply gas evenly over the entire inner circumferential surface of the gas bearing 2 and to stabilize the support of the rotating shaft 3. Therefore, it is easier to obtain a vibration suppression effect on the rotating shaft 3.

[0033] As shown in Figure 2, an atmospheric space 41 is formed on the axial base end L1 side of the sealing surface S. A layer of gas supplied from the gas supply source Gs is formed on the sealing surface S, thereby suppressing fluid leakage.

[0034] Inside the case C, at the axial end L2 of the gas bearing 2, an internal space 42 enclosed by the case C is provided. A layer of gas supplied from the gas supply source Gs is formed on the inner circumferential surface of the gas bearing 2, thereby supporting the rotating shaft 3 without contact.

[0035] Inside the case C, a storage space 40 is provided between the mechanical seal 1 (sealing surface S) and the gas bearing 2 in the axial direction L, where the gas supplied to the sealing surface S and the gas supplied to the gas bearing 2 mix and store.

[0036] In this configuration, the gas supplied to the sealing surface S collides with the sealing end surface 12a of the rotating ring 12, and from this sealing end surface 12a, it branches into the storage space 40 and the atmospheric space 41. Similarly, the gas supplied to the gas bearing 2 flows into the inner circumferential surface of the gas bearing 2, and from this inner circumferential surface, it branches into the storage space 40 and the machine-side space 42. In other words, gas flows into the storage space 40 from both the sealing surface S and the gas bearing 2. Therefore, the pressure in the storage space 40 tends to increase easily.

[0037] In this embodiment, a flow path 6 is provided to guide the gas stored in the storage space 40 to the outside of the storage space 40. The flow path 6 is provided to communicate with both the storage space 40 and the outside of the storage space 40. This makes it possible to release the gas stored in the storage space 40 to the outside of the storage space 40 and to reduce the pressure in the storage space 40.

[0038] In this embodiment, the flow path 6 includes a path formed in the sleeve 31 (rotating shaft 3). The flow path 6 includes a radial flow path 61 that opens into the storage space 40 and extends in the radial direction R, and an axial flow path 63 that communicates with the radial flow path 61 and extends along the axial direction L toward the axial tip side L2. The radial flow path 61 and the axial flow path 63 are in communication via a connection port 62.

[0039] The gas stored in the storage space 40 flows into the radial flow path 61 from its inlet 61a, flows inward in the radial direction R, and flows into the axial flow path 63 via the connection port 62. The gas flowing in the axial flow path 63 toward the axial end L2 is released into the machine interior space 42 from the outlet 63b of the axial flow path 63. As a result, a gas flow toward the axial end L2 is generated near the outlet 63b of the axial flow path 63.

[0040] In this embodiment, the outlet 63b of the axial flow path 63 is located at the same position in the axial direction L as the end E2 of the axial tip side L2 of the gas bearing 2, or at the axial tip side L2 itself. As described above, a gas flow toward the axial tip side L2 is generated near the outlet 63b of the axial flow path 63. Therefore, if dust generated by friction or the like inside the case C is present in the internal space 42, the dust will scatter toward the axial tip side L2, away from the gas bearing 2. As a result, dust will not be scattered onto the gas bearing 2, and the gas bearing 2 and its surroundings will be kept in a clean environment.

[0041] Furthermore, as described above, the gas supplied to the gas bearing 2 flows into the inner circumferential surface of the gas bearing 2, and from this inner circumferential surface it branches into the storage space 40 and the machine-side space 42. The gas that branches into this machine-side space 42 also generates a gas flow from the gas bearing 2 toward the axial end L2. Therefore, in this respect as well, dust in the machine-side space 42 is prevented from scattering onto the gas bearing 2.

[0042] In this embodiment, the flow path 6 includes a discharge flow path 64 that connects the internal space 42 with the outside of the case C. The inlet 64a of the discharge flow path 64 opens into the internal space 42, and the discharge flow path 64 is configured to discharge the gas in the internal space 42 to the outside of the case C. In the illustrated example, the discharge flow path 64 is formed to extend along the radial direction R.

[0043] In this embodiment, the inlet 64a of the discharge channel 64 is located axially towards the tip L2 than the outlet 63b of the axial channel 63. This allows the gas flowing from the outlet 63b of the axial channel 63 to the inlet 64a of the discharge channel 64 to flow toward the axial tip L2. As described above, the outlet 63b of the axial channel 63 is located at the same position in the axial direction L as the end E2 of the axial tip L2 of the gas bearing 2, or toward the axial tip L2. With this configuration, the gas flowing into the internal space 42 from the outlet 63b of the axial channel 63 is more likely to flow toward the inlet 64a of the discharge channel 64 without heading toward the gas bearing 2. Therefore, dust in the internal space 42 can be properly discharged from the discharge channel 64 without heading toward the gas bearing 2.

[0044] [Other Embodiments] Next, other embodiments will be described.

[0045] (1) In the above embodiment, an example was described in which the gas bearing 2 is positioned in the axial direction L relative to the case C by a snap ring 20. However, the embodiment is not limited to this example. As shown in Figure 3, the gas bearing 2 may be positioned in the axial direction L by a part of the case C.

[0046] (2) In the above embodiment, an example was described in which the flow path 6 that guides the gas stored in the storage space 40 to the outside of the storage space 40 includes a radial flow path 61 and an axial flow path 63 formed in the sleeve 31 (rotating shaft 3). However, the embodiment is not limited to this example. As shown in Figure 4, the flow path 6 may be provided to open on the inner and outer sides of the case C so as to directly discharge the gas from the storage space 40 to the outside of the case C.

[0047] (3) In the above embodiment, an example was described in which the gas bearing 2 is located axially towards the tip L2 of the mechanical seal 1. However, the embodiment is not limited to this example. The gas bearing 2 may be located axially towards the base L1 of the mechanical seal 1.

[0048] (4) In the above embodiment, an example was described in which the discharge channel 64 opens into the internal space 42 and extends along the radial direction R. However, the invention is not limited to such an example. The discharge channel 64 only needs to open into the internal space 42 and connect to the outside of the case C, and the shape of the discharge channel 64 can be determined arbitrarily (it does not have to extend along the radial direction R).

[0049] (5) In the above embodiments, an example in which the mechanical seal 1 is of the static pressure type has been described. However, the invention is not limited to such an example. The mechanical seal 1 may also be of the dynamic pressure type.

[0050] (6) In the above embodiment, an example was described in which the gas supplied to the sealing surface S and the gas supplied to the gas bearing 2 are supplied from the same gas supply source Gs. However, the invention is not limited to this example. The sealing surface S and the gas bearing 2 may be configured to be supplied with gas from different gas supply sources Gs.

[0051] (7) In the above embodiment, an example was described in which the flow path 6 includes a radial flow path 61 extending in the radial direction R. However, the embodiment is not limited to this example. In order to achieve the effect of preventing dust from scattering to the gas bearing 2, the flow path 6 only needs to include an axial flow path 63 that extends along the axial direction L toward the axial tip side L2. In other words, the flow path 6 does not need to include a radial flow path 61.

[0052] (8) The configurations disclosed in the embodiments described above can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. With regard to other configurations, the embodiments disclosed herein are merely illustrative in all respects. Therefore, various modifications can be made as appropriate without departing from the spirit of this disclosure.

[0053] [Summary of this embodiment] The following is a summary of this embodiment.

[0054] A shaft sealing device comprising a case and a mechanical seal that penetrates the case and seals the area around a rotating shaft that extends axially, A gas bearing is provided to support the rotating shaft so that it can rotate relative to the case. The gas bearing supports the rotating shaft from the radially outer side and is positioned at a distance in the axial direction from the rotational drive source, which is connected to the rotating shaft at the axial base end side of the mechanical seal.

[0055] The rotating shaft, an essential element of rotating machinery, is connected to a rotational drive source and rotates by obtaining driving force from this source. When the rotating shaft rotates, some vibration inevitably occurs. With this configuration, since a gas bearing that allows for non-contact support is used to support the rotating shaft, the rotating shaft can be supported with low friction, resulting in a high vibration suppression effect. Furthermore, the vibration generated when the rotating shaft rotates tends to be greater at points further axially away from the axial base end where the rotating shaft is connected by the rotational drive source. With this configuration, since such a gas bearing supports the rotating shaft at a position axially away from the rotational drive source connected to the rotating shaft at the axial base end, it is possible to support the tip end of the rotating shaft where vibrations tend to be greater, and a high vibration suppression effect can be obtained. As described above, this configuration makes it possible to realize a shaft sealing device that can easily reduce vibrations in rotating machinery.

[0056] The mechanical seal comprises a rotating ring attached to the rotating shaft and a stationary ring attached to the case, and is configured to form a sealing surface by supplying gas between the rotating ring and the stationary ring in the axial direction. It is preferable that the gas supplied to the sealing surface and the gas supplied to the gas bearing are supplied from the same gas supply source.

[0057] The mechanical seal in this configuration is a so-called static-type mechanical seal, forming a sealing surface with a layer of gas supplied from a gas source, thereby enabling non-contact sealing between the rotating ring and the stationary ring. Furthermore, by adjusting the amount of gas supplied to the sealing surface, the pressure on the sealing surface can be kept constant, thereby suppressing pressure variations on the sealing surface and contributing to vibration suppression. The gas supply to both the sealing surface and the gas bearing is provided by the same gas supply source. This simplifies the structure and allows for efficient use of the gas generated from the gas supply source, ultimately making it easier to reduce costs.

[0058] A storage space is provided inside the case, between the mechanical seal and the gas bearing in the axial direction, where the gas supplied to the seal surface and the gas supplied to the gas bearing mix and store. It is preferable that a channel is provided to guide the gas stored in the storage space to the outside of the storage space.

[0059] Gas supplied to the sealing surface then exits through the sealing surface and flows into the storage space. Similarly, gas supplied to the gas bearing then exits through the gas bearing and flows into the storage space. For this reason, the pressure in the storage space, where gas is collected from multiple locations, tends to rise, and if the pressure in the storage space becomes too high compared to the space outside the machine, it can affect the sealing surface and the gas bearing. However, with this configuration, a flow path is provided to guide the gas stored in the storage space to the outside of the storage space. By releasing the gas to the outside of the storage space, the rise in pressure in the storage space can be suppressed, and backflow of gas can be prevented.

[0060] The flow path includes an axial flow path that extends along the axial direction toward the axial tip side, It is preferable that the outlet of the axial flow path is located at the same position in the axial direction as the axial end of the gas bearing, or on the axial end side.

[0061] According to this configuration, an axial flow path can be used to form a gas flow that moves toward the axial end. The gas moving toward the axial end in the axial flow path is then discharged toward the axial end from the outlet of the axial flow path at the same position as the gas bearing in the axial direction, or further toward the axial end. With this configuration, a gas flow toward the axial end is generated at a position further toward the axial end than the gas bearing. In other words, a gas flow that moves away from the gas bearing can be generated. As a result, for example, dust generated by friction inside the case cannot be scattered onto the gas bearing, and the gas bearing and the environment around it can be kept clean. [Industrial applicability]

[0062] The technology relating to this disclosure can be used in a shaft sealing device comprising a case and a mechanical seal that seals around a rotating shaft that penetrates the case and extends along the axial direction. [Explanation of Symbols]

[0063] 100: Shaft sealing device 1: Mechanical seal S: sealing surface 11: Fixed ring 12: Rotating Ring 2: Gas bearings 3: Rotation axis 6: Flow path 63: Axial flow path 63b: Outlet of axial flow path 40: Storage space C: Case Rs: Rotary drive source Gs: Gas supply source L: Axial direction L1: Axial proximal side L2: Axial tip side R: Radial direction

Claims

1. A shaft sealing device comprising a case and a mechanical seal that penetrates the case and seals the area around a rotating shaft that extends axially, A gas bearing is provided to support the rotating shaft so that it can rotate relative to the case. The gas bearing is a shaft sealing device that supports the rotating shaft from the radially outer side and is positioned at a distance in the axial direction from the rotational drive source which is connected to the rotating shaft at the axial base end side of the mechanical seal.

2. The mechanical seal comprises a rotating ring attached to the rotating shaft and a stationary ring attached to the case, and is configured to form a sealing surface by supplying gas between the rotating ring and the stationary ring in the axial direction. The shaft sealing device according to claim 1, wherein the gas supplied to the sealing surface and the gas supplied to the gas bearing are supplied from the same gas supply source.

3. A storage space is provided inside the case, between the mechanical seal and the gas bearing in the axial direction, where the gas supplied to the seal surface and the gas supplied to the gas bearing mix and store. The shaft sealing device according to claim 2, further comprising a channel for guiding the gas stored in the storage space to the outside of the storage space.

4. The flow path includes an axial flow path that extends along the axial direction toward the axial tip side, The shaft sealing device according to claim 3, wherein the outlet of the axial flow path is located at the same position in the axial direction as the axial end of the gas bearing, or is located on the axial end side.

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