JP2002061750A - Noncontact sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a noncontact sealing device that can prevent leakage of lubricating oil for a bearing on a rotary shaft and an external fluid intrusion, and can provide a continuously constant sealing effect via a simple structure. SOLUTION: The noncontact sealing device 1 comprises a seat ring 10 secured to a rotary shaft 2, and a housing 20 disposed on the rotary shaft 2 via a bearing 3, and has a movable ring 30 mounted on the housing 20 in opposition to the seat ring 10, with the result that the space between the opposite surfaces is a seal clearance h making a hydrostatic gas bearing mechanism M formed by a gas film. The movable ring 30 is displaceable in the direction of the seal clearance h, so that even if a phenomenon occurs to affect the seal clearance h, the movable rang 30 can be displaced to keep the seal clearance h constant and thus maintain a constant sealing effect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a non-contact sealing device, and more particularly to a non-contact sealing device using a rotating shaft end face in a machine tool, a general machine, a chemical facility machine, or the like.

[0002]

2. Description of the Related Art A seal in a rotary shaft device is used for the purpose of preventing a lubricant for a bearing inside a rotary shaft from leaking to the outside, preventing intrusion of fluid from the outside of the rotary shaft, and the like. Further, it is also used when a plurality of fluids such as cutting oil and lubricating oil and chemicals and lubricating oil are disliked to be mixed. In these cases, a contact type member (contact seal) such as an O-ring is interposed between the housing and the rotating shaft to isolate two different fluids. There is no problem if the rotation of the rotating shaft is slow, but for example, pumps, machine tools (spindles of grinding machines)
When severe operating conditions such as high-speed rotation and rotation at high temperature are required, as in the case of the above, the contact type member such as the O-ring and the rotating shaft are in contact with each other, so that the generation of frictional heat and contact Problems such as abrasion of the seal material, durability of the contact seal material, drive loss, and the like occur.

[0003] In order to solve the above-mentioned problem, a technique for sealing in a non-contact manner has been proposed. As a method of keeping the seal gap constant by a non-contact seal using a rotating shaft end face, for example, there is a non-contact type shaft sealing device disclosed in Japanese Utility Model Laid-Open Publication No. 1-144571. This non-contact type shaft sealing device has a driven ring for the housing, a seat ring fixed to the shaft side and a seal end face for holding a delicate seal gap,
When the driven ring deviates from a predetermined position, the back pressure acting behind the driven ring is adjusted to keep the small sealing gap constant.

[0004]

However, in the non-contact type shaft sealing device disclosed in the above publication, a pressure sensor for detecting a seal gap, and a driven ring is driven by a signal from the pressure sensor to keep the seal gap constant. Since a control device including a control valve or the like is required, there is a problem that the device becomes expensive and the device itself becomes large.

An object of the present invention is to provide a non-contact sealing device which can prevent leakage of lubricating oil for bearings of a rotating shaft and intrusion of fluid from the outside, and can always obtain a constant sealing effect with a simple structure. Is to provide.

It is another object of the present invention to provide a non-contact seal device which can be separately recovered without leakage of lubricating oil for bearings of a rotating shaft or mixing of fluid from outside.

[0007]

According to the first aspect of the present invention,
A seat ring fixed to a rotating shaft; and a housing containing a bearing for rotatably supporting the rotating shaft. A movable ring provided in the housing and the seat ring face each other and a seal gap is provided therebetween. In the non-contact seal device, a gas film is supplied to the seal gap between the seat ring and the movable ring by a supply gas supplied from the housing side and supplied through an air supply hole and an ejection port of the movable ring. A non-contact seal device, wherein the movable ring is movable toward and away from the seal gap so as to keep the seal gap constant, and is movable. It is.

In the present invention, since the movable ring which can constitute the hydrostatic air bearing can be displaced by the action of the slide fitting portion, the external force or the thermal expansion of the member affects the seal gap. Occurs, the movable ring is displaced in the seal gap direction, and the seal gap is kept constant. As a result, the gas film characteristics of the seal gap can be kept constant, and a constant sealing effect can be maintained. Also, the facing surface between the seat ring and the movable ring is a static pressure gas bearing that forms a gas film,
Non-contact improves rotational accuracy, durability and driving efficiency. In addition, since a gas film is always formed in the seal gap, high sealing is achieved in a wide range from stationary to high-speed rotation. The effect can be obtained. In addition, the non-contact seal device of the present invention has a simple structure including the seat ring and the movable ring, and therefore can be a low-cost device. The present invention is also suitable for cutting agents, chemicals (highly volatile substances, fluids that easily generate crystals), toxic gases, seawater and lubricants, and even under severe operating conditions, Since the gap between the opposed surfaces is kept constant and a certain sealing effect can be expected, it is effective for a wide range of machinery having a rotating shaft.

In the present invention described above, the supply gas is preferably compressed air supplied from an air supply source, but is not limited to this, and another gas may be used. The size of the seal gap is not limited, and may be any size as long as a gas film can be easily formed in the seal gap. further,
The guide ring is preferably formed of an elastic body.

According to a second aspect of the present invention, in the non-contact seal device according to the first aspect, an annular supply groove having the ejection port is provided on an opposing surface of the movable ring, and inside and outside the supply groove. An annular recovery groove which is concentric with the supply groove and has a recovery hole is formed, the inner recovery groove is capable of recovering lubricating oil and the like from the rotating shaft side, and the outer recovery groove is The present invention is characterized in that an intruding fluid from the outside can be collected.

According to the present invention, inner and outer annular recovery grooves are provided on the surface of the movable ring on the side where the static pressure gas bearing is formed. Since it is recovered from each recovery groove together with the gas discharged from the seal gap, it is reliably recovered from each recovery hole without mixing. Therefore,
The collected fluid such as lubricating oil can be reused just by removing dust and the like by using a filter or the like, so that the lubricating oil and the like can be recycled, and the cost can be reduced.

In the present invention, the inner recovery groove is formed as much as possible on the rotating shaft side, and the outer recovery groove is formed as far as possible so that the static pressure gas bearing can be formed reliably. Preferably, at least one recovery hole in each recovery groove may be provided.

According to a third aspect of the present invention, in the non-contact seal device according to the second aspect, the supply pressure of the supply gas includes a pressure of the lubricating oil on the rotation shaft side and a pressure of the gas outside the housing. And a constant value within a predetermined range determined by the following. According to the present invention, since the sealing gap between the seat ring and the movable ring is always kept constant, a constant sealing effect can be always obtained.

According to a fourth aspect of the present invention, there is provided the non-contact sealing device according to any one of the first to third aspects,
The displacement of the movable ring is performed by the action of a slide fitting portion between the movable ring and the housing. The slide fitting portion includes at least one set of guide rings provided on an inner periphery and an outer periphery of the movable ring. The guide ring is characterized by being formed of an elastic body.

According to the present invention, the movable ring is slid while the gap between the movable ring and the housing portion of the housing accommodating the movable ring is securely sealed. In the present invention described above, the guide ring only needs to be formed of an elastic body, and for example, an O-ring formed of plastic, a metal bellow, or the like can be used.

According to a fifth aspect of the present invention, there is provided a non-contact sealing device according to any one of the first to fourth aspects,
The supply gas is compressed air supplied from an air supply source. According to the present invention, a simple device can be used and handling is easy.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a non-contact sealing device 1 according to a first embodiment of the present invention includes a seat ring 10 fixed to one end of a rotating shaft 2, a housing 20 containing a bearing 3, and a housing 20. Seat ring 1
The movable ring 30 includes a movable ring 30 provided at the end on the zero side and slidable by the slide fitting portion 25, and air supply means 40 for supplying air from the movable ring 30 to the seat ring 10.

The seat ring 10 is formed of a ring-shaped member having a predetermined thickness, and a collar 4 is mounted on the rotating shaft 2 between the seat ring 10 and the bearing 3. The housing 20 is formed of a pipe-like member, and has a thick end portion 2 at one end.
0A, a rectangular groove 20B having a predetermined width and a predetermined depth.
Are formed in an annular shape. The movable ring 30 has a main body 30A inserted into the rectangular groove 20B of the housing 20 so as to be slidable in the axial direction through a slide fitting portion 25, and a main body 30A provided at an end of the main body 30A on the seat ring 10 side. It is formed by a part 30A and a ring part 30B provided integrally.

The air supply means 40 comprises an air passage 47 and an air supply source 41 for supplying the air to the air passage 47. And is provided over. That is, an air supply passage 42 is formed in the housing 20 so as to communicate with the square groove 20B from the outer periphery of the thick portion 20A at the front end thereof, and air of a predetermined pressure is supplied to the air supply passage 42 through the air supply passage 42. The air supply source 41 to be supplied is connected. The air supply passage 42 communicates with an air chamber 43 defined between the rectangular groove 20B and the end of the main body 30A of the movable ring 30, and an air supply hole 44 opened along the axis of the main body 30A. As shown in FIG. 2, the air supply hole 44 is connected to the ring portion 30 through three fluid outlets 45 arranged at equal intervals.
B communicates with an annular air supply groove 46 formed in B.

Here, the ring portion 30B of the movable ring 30
A gap h of a predetermined dimension is formed between the end face of the seat ring 10 on the side of the seat ring 10 and the end face of the seat ring 10 facing the end face. An air film is formed by the compressed air
Thus, the static pressure gas bearing mechanism M is configured.

That is, the compressed air sent from the air supply source 41 passes through the air supply passage 42 of the housing 20 and is supplied to the air chamber 43.
From the air chamber 43, the air supply hole 44, the fluid ejection port 45,
The air flows in the order of the air supply grooves 46 and the compressed air is supplied into the gap h between the opposed surfaces to form an air film. Thus, the static pressure gas bearing mechanism M is configured. For this reason,
Since the high-pressure air is filled in the opposing surface gap h, it is possible to prevent leakage of the bearing lubricating oil inside the rotary shaft 2 and intrusion of intrusion fluid from outside the housing 20.

The slide fitting portion 25 is capable of displacing the movable ring 30 in a direction (thrust direction) in which the movable ring 30 approaches and separates from the seat ring 10 so that the opposed surface gap h is kept constant. It is configured to be. That is, guide ring grooves are formed on the inner circumference and the outer circumference of the main body 30A of the movable ring 30, respectively.
Guide grooves 26 and 27 are mounted in these grooves, respectively. The guide ring 26 is formed of, for example, an elastic body such as plastic, and is provided in close contact with the outer periphery of the main body 30A and the outer periphery of the rectangular groove 20B. The guide ring 27 is provided on the inner periphery of the main body 30A. And square groove 20B
And is provided in close contact with the inner periphery of the.

Next, the principle of the slide fitting portion 25 will be described with reference to FIGS. The movable ring 30 is as shown in FIG. 1, and the pressure distribution in the air chamber 43 and the gap h between the facing surfaces is indicated by arrows. The illustrated pressure is evenly distributed in a ring shape, and the pressure distribution obtained by integrating the pressure distribution in a ring shape is the force acting on the movable ring 30: F1,
F2. Force generated by pressure in air chamber 43: F1
The movable ring 30 is held at a position where the force F2 generated by the pressure of the opposing surface gap h is in an equilibrium state, and a predetermined opposing surface gap at that time is defined as h. The pressure in the air chamber 43 is always constant.

Here, the characteristics of the hydrostatic air bearing will be described. Bearing clearance and bearing load capacity are in a unique relationship,
As the bearing gap increases, the bearing load capacity decreases. Conversely, as the bearing gap decreases, the bearing load capacity increases. In addition, the bearing gap corresponds to the facing surface gap, and the load capacity corresponds to the force F2.

For example, assume that only the seat ring 10 expands from the equilibrium state in FIG. 3 due to thermal expansion as shown in FIG. As a result, the facing surface gap becomes smaller as h-Δh, and the pressure distribution in the gap becomes larger as P2 + ΔP, so that the generated force is also F2 + ΔF and larger than the force F1 generated by the pressure in the air chamber 43 (F1 <F2 + ΔF). . As a result, the movable ring 30 is displaced relative to the seat ring 10 in the direction away from the seat ring 10 (FIG. 5), and is displaced until an equilibrium state where F1 = F2 is established, and a predetermined opposed surface gap h is obtained. When the gap between the facing surfaces is large, the opposite is true.

Accordingly, the forces F1 and F2 are maintained in an equilibrium state by the action of the slide fitting portion 25, so that the pressure distribution and the opposing surface gap, which are the characteristics of the air film, are also kept constant. The surface sealing effect does not change. Note that the force (bearing load capacity) generated by the pressure in the facing surface gap is set in advance so as to be larger than the force generated by the pressure in the air chamber 43.

According to the first embodiment of the present invention described above, the following effects can be obtained. Movable ring 3 that can constitute static pressure air bearing M
0 is guided by the guide rings 26 and 27 constituting the slide fitting portion 25 and can be displaced with respect to the gap between the opposing surfaces. Therefore, a phenomenon occurs that affects the seal gap due to external force or thermal expansion of the member. Also, the movable ring 30 is displaced in the direction of the facing surface gap, and the facing surface gap is kept constant. As a result, the gas film characteristics of the gap between the facing surfaces can be kept constant,
Thereby, a certain sealing effect can be maintained.

The facing surface between the seat ring 10 and the movable ring 30 is a static pressure gas bearing M forming a gas film, and is non-contact, so that rotational accuracy, durability and driving efficiency are improved. Can be.

Since a gas film is always formed in the gap between the facing surfaces, a high sealing effect can be obtained in a wide range from a stationary state to a high-speed rotation. Since the non-contact sealing device 1 has a simple structure including the seat ring 10, the movable ring 30, and the air supply means 40 including the air supply source 41, the device can be a low-cost device.

In the annular air supply groove 46, since the fluid ejection ports 45 for ejecting air are evenly arranged at three places, the compressed air supplied from the air supply source 41 is ejected in a well-balanced manner. A well-balanced air film can be formed.

Next, a second embodiment of the present invention will be described with reference to FIGS.
An embodiment will be described. In this embodiment, the first
The same reference numerals are given to the same structure and the same use members as those of the embodiment, and the detailed description is omitted or simplified. The non-contact seal device 71 of the second embodiment is a fluid recovery device that recovers leakage of bearing lubricating oil and intrusion fluid that enters from outside the housing 20 over the housing 20 and the movable ring 30 in addition to the air supply means 40. A means 50 is provided.

The fluid collecting means 50 includes a lubricating oil collecting means 50.
A and invading fluid recovery means 50B. The lubricating oil collecting means 50A collects and collects the leakage of the lubricating oil from the rotating shaft 2 side. An annular lubricator for collecting the leaked lubricating oil is provided near the inner periphery of the ring portion 30B of the movable ring 130. An oil collecting groove 51 is formed, and the lubricating oil collecting groove 51 is provided with, for example, one lubricating oil collecting hole 52. The lubricating oil collecting hole 52 communicates with an L-shaped cross-section connecting hole 53 formed in the main body 30 </ b> A of the movable ring 130.
It communicates with a lubricating oil exhaust hole 54 opened from OB to the outer periphery. And here, the lubricating oil collecting groove 5
1. The lubricating oil collecting means 50A includes a lubricating oil collecting hole 52, a connecting hole 53, and a lubricating oil exhaust hole 54.

As described above, the intruding fluid collecting means 50B collects the intruding fluid which intrudes from outside the housing 20, and collects the intruding fluid which intrudes from the outside near the outer periphery of the ring portion 30B. An annular intruding fluid recovery groove 55 to be recovered is formed. In the intruding fluid recovery groove 55, for example, one intruding fluid recovery hole 56 is formed. The intruding fluid recovery hole 56 communicates with a connection hole 57 having an L-shaped cross section formed in the main body 30A of the movable ring 130,
The connection hole 57 communicates with an intrusion fluid exhaust hole 58 formed from the rectangular groove 20B of the housing 20 over the outer periphery. And here, the invading fluid recovery groove 55,
The intruding fluid collecting means 50B includes the intruding fluid collecting hole 56, the connecting hole 57, and the intruding fluid exhaust hole 58.

Therefore, for example, the fluid entering from the outside of the rotary shaft 2 is collected in the intruding fluid collecting groove 55 together with the air exhausted from the facing surface gap h, from which the intruding fluid collecting hole 56 and the connecting hole are formed. 57, and are collected in the order of the intruding fluid exhaust hole 58. Further, leakage of the lubricating oil entering from the inside of the rotary shaft 2 is collected in the order of the lubricating oil collecting groove 51, the lubricating oil collecting hole 52, the connecting hole 53, and the lubricating oil exhaust hole 54.

Since the air film is uniformly formed over the entire circumference in the opposing surface gap h between the lubricating oil collecting groove 51 and the intruding fluid collecting groove 55, the annular lubricating oil collecting groove 51 and the intruding fluid collecting groove 55 are formed. The lubricating oil and the intruding fluid cannot enter through the groove 55. As a result, the two fluids, the lubricating oil and the intruding fluid, do not mix.

In the second embodiment, the slide fitting portion 1 which enables the movable ring 130 to slide.
Reference numeral 25 denotes three sets of guide rings 26 and 27 mounted on the inner and outer circumferences of the main body 30A of the movable ring 30 at equal intervals in the thrust direction. Guide ring 26,
27 is provided in close contact with the outer periphery of the main body 30A and the outer periphery of the square groove 20B, and the guide ring 27 is provided in close contact with the inner periphery of the main body 30A and the inner periphery of the square groove 20B. I have.

Therefore, the outer periphery of the main body 30A and the square groove 2
The gap between the outer circumference of the slide chamber 0B and the slide chamber 6
It is divided into two. A gap between the inner circumference of the main body 30A and the inner circumference of the rectangular groove 20B is partitioned into a slide chamber 63 and a slide chamber 64. Even when the movable ring 30 slides, the connection hole 53 on the lubricating oil side is in the slide chamber 61 and the connection hole 57 on the intruding fluid side is in the slide chamber 6.
2, each fits inside.

In the second embodiment, the following effects can be obtained in addition to the same effects as above. An annular lubricating oil recovery groove 51 is formed near the inner periphery of the static pressure gas bearing surface of the movable ring 30, and an intruding fluid recovery groove 55 is formed near the outer periphery. Fluid such as lubricating oil is collected by the lubricating oil collecting groove 51, and the intruding fluid that enters from outside is collected by the intruding fluid collecting groove 5.
Collected by 5 Therefore, the fluids entering from inside and outside of the bearing are surely collected separately without mixing. Then, the collected fluid can be reused simply by removing dust and the like by using a filter or the like (not shown), thereby reducing costs.

The guide rings 26 and 27 are arranged at substantially equal intervals in the thrust direction. In particular, two slide chambers 61 partitioned by the guide ring 26 are provided with a connecting hole 53, a lubricating oil exhaust hole 54, and a connecting hole 57. And the intrusion fluid exhaust hole 58
Are connected. Therefore, even if the movable ring 30 slides and the connecting hole 53 and the lubricating oil exhaust hole 54 are slightly displaced, the lubricating oil and the intruding fluid flow from the connecting hole 53 and the like into the lubricating oil exhaust hole 54 via the slide chamber 61. Therefore, they can be collected smoothly regardless of the sliding of the movable ring 30.

The present invention is not limited to the above embodiments, but may be modified as follows as long as the object of the present invention can be achieved. That is, although the fluid ejection port 45 in each of the embodiments is formed as a throttle of a general hydrostatic bearing, it is not limited to this. For example, a self-contained throttle that acts as a throttle on a virtual cylindrical surface formed by the air supply hole and the bearing gap, an orifice throttle that performs the function of the air supply hole throttle by the resistance of the orifice, and the function of the air supply hole throttle by the resistance of the capillary tube , A diaphragm using a porous material having air permeability on the bearing surface, and a surface diaphragm having a very shallow groove connected to the air supply hole on the bearing surface. Good.

In each of the above embodiments, the fluid ejection port 4
5 is three, but the number is not limited to this, and the number may be two or more. Further, the pressure supplied to the air chamber 43,
Although the pressure supplied to the static pressure gas bearing M is supplied from the same air supply source 41, the pressure is not limited to this and may be supplied separately.

In each of the above embodiments, the air supply source 4
Although the air film is formed by the compressed air supplied from 1, a gas other than air may be used. In each of the above embodiments, one lubricating oil collecting hole 52 is formed in the lubricating oil collecting groove 51, and one intruding fluid collecting hole 56 is formed in the intruding fluid collecting groove 55. Recovery hole 5
The numbers 2, 56 need not necessarily be one, for example, 2
One or three may be provided, and the number of the collecting grooves themselves may be increased. By doing so, the recovery effect is further ensured.

Further, in the lubricating oil recovery and the intruding fluid recovery of each of the above embodiments, a method of positively recovering the lubricating oil by connecting, for example, a vacuum pump to the lubricating oil exhaust hole 54 and the intruding fluid exhaust hole 58 may be adopted. By doing so, the recovery effect is further ensured.

[0044]

As described above, according to the non-contact seal device of the present invention, since the movable ring which can constitute the hydrostatic air bearing M can be displaced by being guided by the guide ring, external force and heat of the member can be reduced. Even if a phenomenon that affects the seal gap due to expansion or the like occurs, the movable ring is displaced in the seal gap direction, and the seal gap is kept constant. As a result, the gas film properties of the seal gap can be kept constant,
A constant sealing effect can be maintained. In addition, the facing surface between the seat ring and the movable ring is a static pressure gas bearing that forms a gas film, and is non-contact, so that rotation accuracy, durability and driving efficiency are improved, and furthermore, a seal gap is provided. Since a gas film is always formed on the substrate, a high sealing effect can be obtained in a wide range from a stationary state to a high-speed rotation. In addition, the non-contact seal device of the present invention has a simple structure including the seat ring and the movable ring, and therefore can be a low-cost device.

In addition, inner and outer annular recovery grooves are provided on the surface of the movable ring on the side where the static pressure gas bearing is formed, and fluids having different characteristics entering from inside and outside of the rotating shaft are discharged from the seal gap. The gas is collected from each of the collecting grooves together with the gas, so that the gas is surely collected from each of the collecting holes without mixing. Therefore, the collected fluid such as lubricating oil can be reused just by removing dust and the like by using a filter or the like, and the lubricating oil and the like can be recycled, thereby reducing costs.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a non-contact sealing device according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a view showing the principle of a slide fitting portion of the embodiment.

FIG. 4 shows the principle of the slide fitting portion of the embodiment, and is a view when the seat ring side is expanded.

FIG. 5 is a view showing a principle of a slide fitting portion of the embodiment, and showing a state where a housing slides.

FIG. 6 is a longitudinal sectional view showing a non-contact sealing device according to a second embodiment of the present invention.

FIG. 7 is a sectional view taken along line VII-VII in FIG. 6;

FIG. 8 is a sectional view taken along line VIII-VIII in FIG. 7;

[Explanation of symbols]

 1,71 Non-contact sealing device 2 Rotary shaft 10 Seat ring 20 Housing 25 Slide fitting portion 26,27 Guide ring 30 Movable ring 40 Air supply means 43 Air chamber 45 Fluid ejection port 46 Air supply groove 50 Fluid recovery means 51 Lubricating oil Recovery groove 55 Infiltration fluid recovery groove M Hydrostatic bearing mechanism

Claims (5)

[Claims] 1. A seat ring fixed to a rotating shaft, and a housing containing a bearing for rotatably supporting the rotating shaft are provided, and a movable ring provided in the housing and the seat ring face each other. And a non-contact seal device that forms a seal gap therebetween, wherein the air is supplied from the housing side and supplied through an air supply hole and an ejection port of the movable ring, and the gap between the seat ring and the movable ring is formed. A static pressure gas bearing that forms a gas film in a seal gap is configured, wherein the movable ring is movable toward and away from the seal gap so as to keep the seal gap constant, and is movable. Non-contact sealing device. 2. The non-contact sealing device according to claim 1, wherein an annular supply groove having the ejection port is formed on an opposing surface of the movable ring, and the supply groove is formed inside and outside the supply groove. An annular recovery groove having a core circle and a recovery hole is formed, and the inner recovery groove is capable of recovering lubricating oil and the like from the rotating shaft side, and the outer recovery groove is capable of receiving intrusion fluid from the outside. A non-contact sealing device characterized by being recoverable. 3. The non-contact seal device according to claim 2, wherein a supply pressure of the supply gas is within a predetermined range determined by a pressure of the lubricating oil on the rotation shaft side and a pressure of a gas outside the housing. A non-contact sealing device characterized by a constant value of 4. The non-contact seal device according to claim 1, wherein the movable ring is displaced by an action of a slide fitting portion between the movable ring and the housing. The non-contact sealing device is characterized in that the mating portion includes at least one pair of guide rings provided on the inner and outer circumferences of the movable ring, and the guide ring is formed of an elastic body. 5. The non-contact sealing device according to claim 1, wherein the supply gas is compressed air supplied from an air supply source.