Seal structure for pressurized container, cooling treatment apparatus, multi-chamber heat treatment apparatus, pressure regulating method, and operating method

This shaft seal structure has at a fitting portion between a container wall of a pressurized container in which high pressure gas is enclosed and a rotating shaft that passes through the container wall: O-rings that are disposed at least two locations in the axial direction of the rotating shaft; and grease that is pressurized.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a 35 U.S.C. §371 National Phase conversion of PCT/JP2006/307359, filed Apr. 6, 2006. The PCT International Application was published in the Japanese language.

TECHNICAL FIELD

The present invention relates to a seal structure, a cooling treatment apparatus, a multi-chamber heat treatment apparatus, a pressure regulating method, and an operating method.

BACKGROUND ART

A heat treating apparatus that performs so-called tempering by heating and cooling a metal member that is a treatment object conventionally performs cooling treatment by placing the treatment object that has been heat treated midway in a flow path of a cooling gas that circulates in a heat treating furnace.

Specifically, the treatment object is placed in a cooling chamber that is formed within the heat treating furnace, and by supplying a coolant gas to this cooling chamber and rotating a fan, the coolant gas is circulated (refer to Patent Document 1).

In this kind of heat treating apparatus, since a pressurized coolant gas is used, the cooling chamber is constituted by a pressurized container. For this reason, the motor that rotates the fan is arranged inside of the pressurized container that serves as the cooling chamber.

However, a motor that can be used inside of a pressurized container is costly due to its special features, so using a moderately priced general-purpose motor has been desired. In the case of using a general-purpose motor, in order to transmit the rotation of the general-purpose motor that is arranged outside of the pressurized container, it is necessary to pass the output shaft of the general-purpose motor or the rotating shaft that is connected thereto through the container wall of the pressurized container and arrange a shaft seal structure between the output shaft or rotating shaft and the container wall. A magnetic seal, for example, has been proposed as the shaft seal structure that can be used in the container wall of the pressurized container.

However, since the interior of the pressurized container that serves as the cooling chamber is raised to a pressure of, for example, 30 atm (3.0 MPa), the problem arises of not being able to readily seal the container with the magnetic seal.

The present invention was achieved in view of the above circumstances, and has as its object to provide a shaft seal structure that is capable of being suitably applied to a rotating shaft that passes through a container wall of a pressurized container, a cooling treatment apparatus that is provided with this shaft seal structure, a multi-chamber heat treatment apparatus, a pressure regulating method, and an operating method.

DISCLOSURE OF THE INVENTION

The shaft seal structure according to the present invention is characterized by providing at a fitting portion between a container wall of a pressurized container in which high pressure gas is enclosed and a rotating shaft that passes through the container wall O-rings that are disposed at least two locations in the axial direction of the rotating shaft; and grease that is pressurized to approximately the same pressure as the pressure of the high pressure gas in a space that is formed by the rotating shaft, the container wall, and the O-rings.

Also, it is characterized by having a grease pressure measuring portion that measures changes in the pressure of the grease that is filled in the space, and a gas leakage detecting portion that detects leaks of the high pressure gas from the pressurized container based on the measurement result of the grease pressure measuring portion.

A cooling treatment apparatus according to the present invention that disposes a treatment object that has been subjected to heat treatment in a pressurized container and cools the treatment object by supplying high pressure gas in the pressurized container and circulating it with a fan, characterized by providing, at a fitting portion between a rotating shaft that passes through the container wall of the pressurized container to transmit torque to the fan and the container wall, a shaft seal structure comprising O-rings that are disposed at least two locations in the axial direction of the rotating shaft; and grease that is pressurized to approximately the same pressure as the pressure of the high pressure gas in a space that is formed by the rotating shaft, the container wall, and the O-rings.

Also, it is characterized by the shaft seal structure having a grease pressure measuring portion that measures changes in the pressure of the grease that is filled in the space, and a gas leakage detecting portion that detects leaks of the high pressure gas from the pressurized container based on the measurement result of the grease pressure measuring portion.

Also, it is characterized by having an acceleration mechanism that causes the fan to rotate at a higher rotational frequency than the rotating axis.

A multi-chamber heat-treatment apparatus that has a heating chamber that performs heat treatment on a treatment object and a cooling chamber that performs cooling treatment on the treatment object that has been subjected to heat treatment in the heating chamber, characterized by using the abovementioned cooling treatment apparatus as the cooling chamber.

A pressure regulating method according to the present invention is characterized by, in the abovementioned shaft seal structure, pressurizing the grease to a first set pressure and maintaining that state, and pressurizing the grease to the first set pressure again when the pressure of the grease has fallen to a second set pressure.

An operating method according to the present invention is characterized by, in the abovementioned cooling treatment apparatus, pressurizing the grease to a first set pressure and maintaining that state, and stopping the cooling treatment operation when the pressure of the grease has fallen from a second set pressure to a third set pressure in a predetermined time.

EFFECT OF THE INVENTION

With the shaft seal structure according to the present invention, it is possible to apply a shaft seal structure whose structure is simple and moderately priced and having high reliability to a rotating shaft that passes through the container wall of a pressurized container. Also, since changes in the filling pressure of the grease that is filled at a predetermined pressure between the plurality of O-rings that constitute the shaft seal structure are detected, it is possible to detect that the sealed state by the shaft seal structure has become unmaintainable.

With the cooling treatment apparatus according to the present invention, since a shaft seal structure whose structure is simple and moderately priced and having high reliability is applied to a rotation shaft that transmits rotation to a fan that is disposed in the cooling container and passes through the container wall of a pressurized container, it is possible to use a moderately priced general-purpose motor as the motor for driving the rotating shaft. Also, it is possible to detect that the sealed state by the shaft seal structure that is applied to the rotation shaft has become unmaintainable. Also, it is possible to rotate the fan at the desired rotational frequency even when the predetermined rotational frequency of the rotating shaft is low.

With the multi-chamber heat-treatment apparatus according to the present invention, it is possible to reliably perform cooling treatment of a treatment object X and possible to obtain a moderately priced apparatus.

With the pressure regulating method according to the present invention, even when the pressure of the grease that is filled at the first set pressure falls to a second set pressure in the abovementioned shaft seal structure, since the grease is pressurized again, it is possible to prevent a leakage of high-pressure gas due to the sealed state by the shaft seal structure becoming umaintainable.

With the operating method according to the present invention, even when it is determined that the sealed state by the shaft seal structure has become unmaintainable in the abovementioned cooling treatment apparatus, it is possible to restrict damage to the shaft seal structure to a minimum.

DESCRIPTION OF REFERENCE NUMERALS

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinbelow, preferred embodiments of the present invention shall be described with reference to the appended drawings.

FIG. 1is a schematic cross-sectional view of the overall structure of a multi-chamber heat treatment apparatus1according to the present embodiment.

The multi-chamber heat treatment apparatus1is a multi-chamber-type heat treatment apparatus that is provided with a cooling chamber2that cools a treatment object X and a heating chamber3that heats the treatment object X, and additionally has an intermediate chamber4that is arranged between the cooling chamber2and the heating chamber3.

The cooling chamber2is set to have an approximately cylindrical shape, and is set so that the central axis of this cylindrical shape is horizontally oriented. A clutch-type door5that moves horizontally in the axial direction of the cooling chamber2is provided on one side of the cooling chamber2(the right side inFIG. 1), and a clamp-type vacuum-shield door6that opens and closes vertically is provided on the other side (the left side inFIG. 1). Note that the entity that includes the cooling chamber2and a cooling fan motor20and the like described below is called a cooling treatment apparatus2a.

The inside space of the multi-chamber heat treatment apparatus1enters a sealed state of being shut off from the outside in the state of the door5being closed. A wind path chamber7with a substantially parallelepiped shape that is long in the central axis direction of the cooling chamber2is installed inside of this cooling chamber2, and gas flow guide plates8a,8bthat adjust the flow path direction of the coolant gas in the cooling chamber2are respectively provided at the top and bottom of the wind path chamber7. Also, the interior of the cooling chamber2outside of the wind path chamber7is vertically divided by a partition plate not illustrated.

A side surface portion7aof one side of the wind path chamber7(the right side inFIG. 1) that corresponds to the lengthwise direction of the wind path chamber7is open, while a side surface portion7bof the other side (the left side inFIG. 1) is fixed to the vacuum shield door6and formed to be freely detachable with a main body7cof the wind path chamber7.

Lattice-shaped flow regulating plates9a,9bthat regulate and pass the coolant gas are respectively provided at the upper wall portion and lower wall portion of the wind path chamber7. Also, a transfer table11for transporting a tray10that carries the treatment object X in the axial direction of the cooling chamber2is installed inside of the wind path chamber7, and a plurality of free rollers12are provided in the transfer table11to rotate freely in the transport direction of the tray10I Also, the tray10is formed for example in a lattice shape so that the coolant gas is capable of passing through.

The door5is formed in a hollow shape, and the interior is equipped with a heat exchanger15, a cooling fan16, and dampers17a,17b. The heat exchanger15cools the coolant gas by performing heat exchange between water and the coolant gas, and is arranged inside of a heat-exchanger storing chamber18that is disposed within the door5. The cooling fan16serves to adjust the flow quantity of the coolant gas which has passed a gas passage port19afrom the inside of the heat exchanger15, and is disposed between the heat exchanger15and the inner surface of the door5, that is, so as to be removed in the horizontal direction from the side surface of the treatment object X that is placed in the cooling chamber2. This cooling fan16is driven by a cooling fan motor20that is arranged so as to project from the door5.

The dampers17a,17bdetermine the blowing direction (cooling wind direction) of the coolant gas with respect to the treatment object X under the control of a cooling control portion that is not illustrated, and selectively close gas passage ports19a,19b,19c,19dthat are formed at the upper side of the heat-exchanger storing chamber18. Note that the interior of the door5outside of the heat-exchanger storing chamber18is vertically divided by a partition plate not illustrated.

The heating chamber3is set to have an approximate cylindrical shape with water-cooled double walls, with water interposed between the inner wall and the outer wall, and is disposed facing the cooling chamber2. Also, a conveying rod22for conveying the treatment object N by conveying the tray10on which the treatment object X is placed inside of the multi-chamber heat treatment apparatus1is disposed inside of a conveying rod housing chamber21that is coupled to the heating chamber3.

A heating container23that is set to a substantially parallelepiped shape is provided inside of the heating chamber3. A heat insulation door24(heat chamber door) that opens and closes vertically is installed on one side of the heating container23(the side that faces the cooling chamber2), and a conveying rod door25that serves and the entrance/exit of the conveying rod22is provided at the other side. This conveying rod door25is opened and closed in the vertical direction by a raising-lowering mechanism26that is installed so that it projects from the outer wall of the heat chamber3.

A transfer table28that has a plurality of free rollers27for moving the tray10on which the treatment object X is placed in the axial direction of the heating chamber3is installed inside of the heating chamber23, and this transfer table28is arranged on the extended line of the transfer table11that is installed inside of the wind path chamber7. Note that the conveying rod door25, the transfer table28, and the tray10are designed to have heat insulating properties similarly to the heat insulation door24. Also, a plurality of heaters29for heating the treatment object X are provided above and below the treatment object X so that the entire treatment object X is uniformly heated.

The intermediated chamber4is set to be hollow with a substantially rectangular shape, and is disposed between the cooling chamber2and the heating chamber3. At the upper portion thereof are disposed a raising-lowering mechanism55athat consists of a hoist for raising and lowering the vacuum shield door6and a heat insulation door raising-lowering portion55bfor raising and lowering the heat insulation door24.

A pressure reducing apparatus that is not illustrated is installed on the outside of the cooling chamber2, the heating chamber3, and the intermediate chamber4. This pressure reducing apparatus evacuates the interior of the cooling chamber2and the heating chamber3, and is connected to the cooling chamber2and the heating chamber3, respectively. Also, a coolant gas supply apparatus that is not illustrated is also provided on the outside of the cooling chamber2, the heating chamber3, and the intermediate chamber4. This coolant gas supply apparatus supplies coolant gas to the inside of the cooling chamber2at a predetermined pressure based on a coolant gas control signal that is input from the cooling control portion. Note that during maintenance work on the multi-chamber heat treatment apparatus1, since coolant gas may be supplied to the heating chamber3and the intermediate chamber4that are external to the cooling chamber2, the coolant gas supply apparatus is also connected to the intermediate chamber4.

The cooling control portion controls the cooling treatment in the cooling chamber2based on a temperature signal that is input from a temperature measurement portion32, that is, the temperature of the treatment object X. Also, it outputs a motor driving signal via a cooling fan inverter not illustrated to the cooling fan motor20.

Next, the constitution of the shaft seal structure120that is provided in the door5shall be described.

FIG. 2is a cross-sectional view showing the constitution of the shaft seal structure120according to the present embodiment.FIG. 3is a magnified cross-sectional view of the shaft seal structure120.

A transmission mechanism100for transmitting rotation of the output shaft20aof the cooling fan motor20to the cooling fan16is provided between the cooling fan16that is disposed in the cooling chamber2and the cooling fan motor20that is disposed outside of the cooling chamber2.

The transmission mechanism100is constituted from a pair of gears101,102that are provided outside of the cooling chamber2, a pair of gears103,104that are provided inside of the cooling chamber2, and a rotating shaft108that passes through the door5. The gear101has 80 teeth, and is coupled to the output shaft20aof the cooling fan motor20. The gear102has 40 teeth and is connected to one end of a rotating shaft108upon meshing with the gear101. The gear103has 80 teeth, and is coupled to the other end of the rotating shaft108. The gear104has 25 teeth and is connected to a rotating shaft16aof the cooling fan16upon meshing with the gear103. With such a constitution, when the output shaft20aof the cooling fan motor20is rotated at 100 rpm, the cooling fan16rotates at 640 rpm.

The rotating shaft108is inserted in a through hole112of a bush110that has a flange111on one end, and in addition this bush110is fitted in a through hole5athat is formed in the door5. The rotating shaft108is supported by the bush110via the bearings121,122that are provided at both ends of the through hole112of the bush110. An O-ring115is disposed on the flange111of the bush110, and so the flange111is sealed by the O-ring115as a result of the flange111abutting the outer surface of the door5.

Then, the shaft seal structure120is disposed in the cylindrical gap that is formed between the rotating shaft108and the bush110. The shaft seal structure120is constituted from two O-rings123,124that are disposed in a gap between the rotating shaft108and the bush110and the grease R that is filled between the two O-rings123,124.

In the case of rotating the output shaft20aat a rotational frequency of 100 rpm, the rotational frequency of the rotating shaft108is 200 rpm. When the rotational frequency of the rotating shaft108is 200 rpm or less, sufficient sealing is possible with the O-rings123,124. In this way, by disposing the transmission mechanism100on the inside of the door5(interior of the cooling chamber2), it is possible to keep the rotational frequency of the rotating shaft108that passes through the door5low while rotating the cooling fan motor20at a desired rotational frequency.

Thereby, it is possible to apply the shaft seal structure120with a structure that is simple, moderately priced, and highly reliable as a shaft seal structure that is provided between the door5and the rotating shaft108. Also, since the cooling fan motor20is disposed outside of the door5(outside of the cooling chamber2), it is possible to use a moderately priced general-purpose motor instead of a specialized motor for use inside of the pressurized container as the cooling fan motor20. Accordingly, it is possible to keep down the manufacturing cost of the multi-chamber heat treatment apparatus1.

The grease R is filled at a predetermined pressure from the flange111side of the bush110into a space S that is enclosed by the two O-rings123,124within a gap that is formed between the rotating shaft108and the bush110. That is, two grooves for disposing the two O-rings123,124and a grease supply hole113that connects to the flange111side from between these two grooves is formed on the inner surface of the through hole112of the bush110.

An inert gas supplying portion150that is capable of pushing the grease R at a predetermined pressure with inert gas is coupled to the flange111side of the grease supply hole113. The inert gas supplying portion150consists of a pressure source151, a pressure sensor152, an electromagnetic valve153, and a pressure controller154. The pressure source151is capable of supplying inert gas at the same pressure as the set pressure of the cooling chamber2. The pressure sensor152indirectly measures the filling pressure of the grease R that is filled into the space S by measuring the pressure of the inert gas that has been supplied to the grease supply hole113. The electromagnetic valve153is a valve that performs supplying and cutting off of inert gas to the grease supply hole113from the pressure source151. The pressure controller154controls the electromagnetic valve153based on the measurement result of the pressure sensor152.

Next, the operation of the multi-chamber heat treatment apparatus1constituted in this manner shall be described.

First, a treatment object that is placed on the tray10is placed on the transfer table11inside of the wind path chamber7in the state of the door5being separated from the cooling chamber2. Then, the door is abutted against the cooling chamber2, and the cooling chamber2is closed. The cooling chamber2, the heating chamber3and the intermediate chamber4are evacuated by driving of a pressure reducing apparatus57.

Then, the raising-lowering mechanism26, the raising-lowering mechanism55a, and the heat insulation door raising-lowering portion55bare driven, whereby the conveying rod door25, the vacuum shield door6, and the heat insulation door24are opened. Here, the tray10is engaged and pulled by the distal end portion of the conveying rod22, whereby the treatment object X is transported from the transfer table11that is inside of the wind path chamber7onto the transfer table28in the heating chamber23.

Then, the raising-lowering mechanism26and the heat insulation door raising-lowering portion once again55bare driven, whereby the conveying rod door25and the heat insulation door24are closed. Note that at this time, the raising-lowering mechanism55ais not driven, and so the vacuum shield door6is maintained in an opened state. In this state, the treatment object X is heated to a predetermined temperature by the heater29.

When the heating of the treatment object X is completed, the conveying rod door25and the heat insulation door24are opened, and the treatment object X is again transported to the transfer table11in the wind path chamber7by the conveying rod22. Then, when then treatment object X has been transported to the transfer table11in the wind path chamber7, the vacuum shield door6is hermetically sealed.

Then, the coolant gas is supplied to the cooling chamber2by a coolant gas supply apparatus (not shown). This coolant gas is circulated in the cooling chamber2by the cooling fan16, whereby the treatment object X is cooled. At this time, by changing the gas passage ports19ato19dthat each close at a predetermined time by the dampers17aand17b, the direction in which the coolant gas flows is changed, and thereby the coolant gas is blown all over the treatment object X, so that the treatment object X is uniformly cooled.

Here, the operation of the shaft seal structure120shall be described.

FIG. 4shows changes in the filling pressure of the grease R of the shaft seal structure120.

The coolant gas that is supplied from the coolant gas supply apparatus to the cooling chamber2is raised to a pressure of approximately 30 atm (3.0 MPa). By pressurizing the coolant gas, it is possible to cool the treatment object X in a short time.

Even when the interior of the cooling chamber2has been pressurized to approximately 30 atm, the shaft seal structure120is capable of withstanding the difference in pressure with the outside of the cooling chamber2at a high probability. Specifically, by setting the dimension of the gap in the radial direction of the space S in a predetermined range in accordance with the hardness of the Wrings123,124, it is possible to suppress projection of the Wrings123,124from the grooves that are formed in the inner surface of the through hole112of the bush110without using a backup ring (for example, refer to JIS-B-2406).

However, in the case of no longer being able to maintain the sealed state with the shaft seal structure120, the coolant gas in the cooling chamber2leaks to outside from the gap in which the O-rings123,124are disposed, that is, the space between the rotating shaft108and the bush110. As a result, there is a high possibility that the cooling process of the treatment object X may be incomplete.

Therefore, it is detected in the following manner whether or not the sealed state by the shaft seal structure120can no longer be maintained.

First, simultaneously with or prior to the pressurization of the coolant gas, an inert gas is supplied from the pressure source151to the grease supply hole113under the control of the pressure controller154. Thereby, the grease R is raised to the same pressure as the inside of the cooling chamber2or a slightly higher pressure (for example, 31 atm (3.1 MPa), with this pressure called a first set pressure). Thereby, since the pressure of the cooling chamber2and the space S become approximately the same, or the pressure of the space S becomes higher than the cooling chamber2, leakage of the coolant gas is more reliably prevented.

Next, by operating the electromagnetic valve153to shut off the supply of inert gas from the pressure source151to the grease supply hole113, the state of the grease R being pressurized is maintained.

As shown inFIG. 4, even in the case where the coolant gas in the cooling chamber2is normally enclosed by the shaft seal structure120, the filling pressure of the grease R of the shaft seal structure120falls gradually (refer to line L1). This is because the grease R gradually leaks from the space S to the outside of the O-rings123,124, that is, to the inside or the outside of the cooling chamber2. The filling pressure of the grease R of the shaft seal structure120is detected by the pressure sensor152as described above.

If the pressure sensor152detects that the filling pressure of the grease R is approximately the same as the pressure in the cooling chamber2or has dropped to a slightly lower pressure (this pressure being called a second set pressure), the pressure controller154operates the electromagnetic valve153to resupply inert gas from the pressure source151to the grease supply hole113. Thereby, the filling pressure of the grease R is again pressurized to 31 atm. By repeating this process, leakage of the coolant gas to outside of the cooling chamber2due to the enclosure state by the shaft seal structure120not being maintainable is prevented while the process of cooling the treatment object X in the cooling chamber2is performed. Note that when the second set pressure is detected by the pressure sensor152, an alarm or the like may be issued.

If the processing object X is cooled to a predetermined temperature, the door5will be detached from the cooling chamber2, and the processing object X will be brought outside.

On the other hand, regardless of the abovementioned response, in the case of the enclosure state by the shaft seal structure120becoming unmaintainable and the coolant gas of the cooling chamber2leaking to outside through the space S, the filling pressure of the grease R of the shaft seal structure120rapidly falls (refer to line L2).

If the filling pressure of the grease R of the shaft seal structure120falls to a pressure that is sufficiently lower than the pressure in the cooling chamber2(with this pressure being called a third set pressure) in for example a short span of time of about 1 second, the process of cooling the treatment object X is stopped. Specifically, the coolant gas that is filled inside of the coolant chamber2is released from a safety valve not illustrated that is provided in the cooling chamber2. Also, a measure is performed such as stopping driving of the cooling fan motor20. In addition, the pressurization of the grease R of the shaft sealing configuration120by the inert gas supplying portion150is stopped, and so becomes atmospheric pressure.

Thereby, even when the enclosure state by the shaft seal structure120has become unmaintainable, since the cooling fan motor20(output shaft20a) is stopped at an early stage, it is possible to prevent the two O-rings123,124of the shaft seal structure120from cracking or being severed.

Accordingly, reuse of the shaft seal structure120is possible without disassembling and repairing. Note that when the reason for not being able to maintain the enclosure state by the shaft seal structure120is due to breakage of the two O-rings123,124, the O-rings123,124are replaced.

FIG. 5shows a transmission mechanism200and a shaft seal structure220.FIG. 6is an enlarged cross-sectional view of the shaft seal structure220.

The shaft seal structure220that is a variation of the shaft seal structure120is constituted from three O-rings123,124,125on the rotating shaft108and grease R that is filled between the three O-rings123,124,125. The grease R that is filled between the O-rings123,124among the O-rings123,124,125is filled at a predetermined pressure from the flange111side of the bush110via the grease supply hole113. That is, the inert gas supplying portion150is coupled to the grease supply hole113. Note that the filling pressure of the grease R that is filled between the O-rings124,125is filled at the same pressure as the outside atmosphere. In this way, the shaft seal structure220may be provided with three or more O-rings. In the case of providing three or more O-rings, the grease R that is set to the first set pressure is filled between the two O-rings123,124that are closest to the cooling chamber2. Note that the grease R that is set to the first set pressure may also be filled between the O-rings124,125.

The transmission mechanism200that is a variation of the transmission mechanism100is constituted from a pair of gears101,102that are provided outside of the cooling chamber2, a pair of gears103,104,105that are provided inside of the cooling chamber2, and a rotating shaft108that passes through the door5. In this way, it is possible to make changes as required to the configuration of the transmission mechanism200such as the size and required rotational frequency of the cooling fan16, or the specifications of the cooling fan motor20. However, the rotational frequency of the rotating shaft108needs to be 200 rpm or less. This is in order to enable use of O-rings123,124,125as the shaft seal structure120,220.

Note that it is possible to use an engine instead of the cooling fan motor20. In the case of using an engine, it is preferred to operate the engine prior to the process of cooling treatment object X in order to obtain a stable output (rotation). For example, by running the motor from 30 seconds prior to starting the process of cooling treatment object X, stabilized output is obtained at the time of the cooling process.

Also, instead of the case of coupling the inert gas supplying portion150to the shaft seal structure120,220, by coupling a pipe of the same pressure that is connected to the cooling chamber2to the shaft seal structure120,220, the grease R that is disposed between the O-rings may be filled at a predetermined pressure.

Also, the shaft seal structure120,220is not limited to the case of being disposed at the door5of the cooling chamber2. Provided it is a rotating shaft that passes through container wall of a pressurized container, it may be any kind of container, In this case, by coupling the inert gas supplying portion150to the shaft seal structure120,220, there is no need to detect the filling pressure of the grease R that is disposed between the plurality of O-rings.

INDUSTRIAL APPLICABILITY

The shaft seal structure of the present invention can be applied to a fitting portion between a container wall of a pressurized container in which high-pressure gas is enclosed and a fitting portion with a rotating shaft that passes through this container wall.