JP2006242204A - Sealing device with garter spring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing device with a garter spring having stable sealing performance and longer life while preventing the opening of a seal portion due to so-called stick slip and actualizing stable sealing even when sealed fluid pressure is changed. <P>SOLUTION: The sealing device with the garter spring comprises a seal body 1 and the ring garter spring 2 mounted at the back face position of the seal portion 4 of the seal body 1. Part of the outer diameter face of the garter spring 2 is covered with a covering elastic member 8 formed of a material different from that of the seal body 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a seal device with a garter spring such as a lip seal used for a shaft seal portion of various devices.

  As shown in the following Patent Document 1 and the like, a lip seal is generally a seal body (rubber material) that plays the role of the seal, and a garter attached to the back of the lip portion (seal part) in the seal body. It consists of two members, a spring. Nitrile rubber, fluorine rubber, or the like is used as the rubber material constituting the seal body. Many garter springs are made of materials such as spring steel, stainless steel, and hastelloy.

  A garter spring is a helical coil spring that has a circular shape with both ends connected. In order to maintain the radial clamping force between the lip (seal part) of the lip seal and the shaft, a circumferential tension is applied. It is used in the state given.

  With conventional lip seals, the sliding contact portion between the shaft and the tip of the lip is in an extreme state of frictional wear under high pressure and / or high speed high load conditions. The temperature rises and so-called stick slip occurs.

  This stick slip is caused by softening and seizure of the rubber material due to a high load and high temperature state of the lip tip sliding contact surface. When this stick-slip phenomenon occurs, the lubrication state at the tip of the lip reaches an extremely poor environment due to discontinuous adhesion and breakage of the sliding contact surface.

  At this time, in the conventional lip seal, the garter spring has a direction along the axis of the rotation shaft (X direction) and a radial direction of the rotation shaft (Y direction) in the spring groove formed on the back surface of the lip portion. Then, a peristaltic motion occurs in the longitudinal direction of the garter spring, that is, in the circumferential direction (Z direction) of the rotating shaft. That is, the garter spring starts a zigzag movement in the X and Y directions, and the garter spring moves in the Z direction while swinging in the spring groove.

  At this time, the sliding contact surface at the tip of the lip is instantaneously separated from the rotation shaft surface (opening) to induce a phenomenon that the liquid to be sealed leaks from the opening surface. As described above, it is presumed that one of the causes of leakage is that the garter spring is oscillated when stick slip occurs in the lip seal, and at this time, the sealing surface opens and leads to leakage.

  The general idea of designing lip seal garter springs is that permanent deformation is unavoidable with rubber alone, so metal springs are assisted, thereby reducing the reduction in tightening allowance. Therefore, in general, the garter spring is simply used in a state where it is fitted in the spring groove, and there is no measure for limiting the behavior of the garter spring.

  Therefore, in the conventional device configuration in which the garter spring is simply fitted in the spring groove, when the extreme state where the stick slip occurs is reached, the lip tip sliding contact boundary surface is always unstable. Indicates.

  Further, the conventional method has a problem that the garter spring swings in the X and Y directions and moves greatly in the Z direction, so that the seal surface is always unstable and causes leakage. .

Furthermore, in a normal lip seal, when the pressure of the object to be sealed increases, the shaft clamping force increases accordingly, increasing the load applied to the seal surface, increasing the heat generated by sliding, hardening the lip tip, and firing. Adverse effects such as damage to the rotating shaft due to the sticking start to appear, and there is a problem that the life of the seal is reduced.
JP-A-11-230362

  The present invention has been made in view of such a situation, and can prevent the opening of the seal portion due to so-called stick slip, and achieves a stable seal even when the sealed fluid pressure fluctuates. An object of the present invention is to provide a sealing device with a garter spring capable of extending the life.

In order to achieve the above object, a sealing device according to the present invention comprises:
A seal device with a garter spring having a seal body and a ring-shaped garter spring attached to a back surface position of a seal portion in the seal body,
A part of the outer diameter surface of the garter spring is covered with a covering elastic member made of a material different from that of the seal body.

  In the present invention, by covering a part of the outer periphery of the garter spring with the covering elastic member, the movement of a part of the garter spring is restricted, and the other part is freely movable. For this reason, according to the present invention, the garter spring can adjust the shaft tightening pressure and maintain an appropriate tightening allowance, and further make the most of the utility of the garter spring configured as a sealing component. it can.

  That is, the covering elastic member in the garter spring acts to restrain the longitudinal movement (Z direction) of the garter spring. In addition, since the entire circumference of the garter spring is not covered with the covering elastic member, it is generated and transmitted to the tip of the lip with respect to the movement in the direction (X and Y directions) perpendicular to the longitudinal direction of the garter spring. The degree of freedom to absorb the minute vibrations.

  In the present invention, since only a part of the outer periphery is covered with the covering elastic member, the position of the garter spring is fixed as the core of the seal body on a macro scale while absorbing vibration on a micro scale. Will be.

As a result, according to the present invention, the following effects can be obtained.
The garter spring with the covering elastic member improves the functionality as a sealing device, and it is possible to suppress the opening on the sliding surface of the seal portion due to the stick slip. Further, by making it difficult for the opening on the sliding surface of the seal portion to occur, the sealing performance can be stabilized and a longer life can be expected.

  In addition, the elastic member for covering of the garter spring primarily catches the pressure fluctuation by buffering the fluctuation of the sealed object pressure, and secondarily transmits the pressure fluctuation to the seal sliding surface (lip sliding surface). Therefore, it becomes a binding force lip seal which is insensitive to pressure fluctuation, and the sealing performance is stabilized.

  As the material of the covering elastic member in the present invention, it is preferable to use a rubber-like elastic substance having a large elongation characteristic and a high tensile strength. As the elongation characteristic, the elongation defined by JIS (K6251) is preferably 100% or more, more preferably 300% or more, and particularly preferably 600% or more.

  Preferably, the garter spring is fitted in a spring groove formed at the back surface position of the seal portion in the seal body so that a part of the outer circumference of the garter spring is embedded and the rest is exposed. The outer diameter surface of the garter spring exposed from the spring groove is covered with the covering elastic member.

  In a conventional sealing device with a garter spring, generally, a part of the outer diameter surface of the garter spring is exposed from the sealing member on the sealed body side of the garter spring, and the remaining portion is fitted in the spring groove of the sealing member. Are combined. In the present invention, the garter spring corrosion resistance can be maintained by a relatively inexpensive and easy method by forming the covering elastic member on the exposed portion of the outer periphery of the garter spring.

  In the conventional method, as a countermeasure against corrosion of the garter spring against the corrosive sealing liquid, (i) a method using a corrosion-resistant metal material (Hastelloy, stainless steel, etc.) and (ii) covering the surface of the garter spring with a rubber or plastic tube Etc. are used. However, in these methods, the method (i) tends to be high in cost, and in the method (ii), there is a problem that the corrosive liquid enters from the joint of the tube and promotes corrosion. is there. The present invention eliminates these drawbacks.

  Preferably, an outer diameter surface of the garter spring exposed from the spring groove is covered with the covering elastic member, and the seal body and the garter spring are integrated with the covering elastic member.

  In this case, the stability of the seal dimensions can be ensured by joining and integrating the seal body and the garter spring with a covering elastic member while fixing the inner diameter of the seal body on a liner having a seal ring size of a predetermined dimension in advance. Is secured.

  Preferably, 1/2 to 1/4 of the entire circumference of the outer diameter surface of the garter spring is covered with the covering elastic member in whole or in part. Even if the covering ratio is too small or too large, the effect of the present invention tends to be reduced.

  Preferably, it is covered with the covering elastic member continuously or intermittently along the axial direction of the garter spring. In the present invention, it is preferable that the elastic member for covering is continuously covered along the axial direction of the garter spring, but the effect of the present invention can be obtained even if it is formed somewhat intermittently.

  Preferably, the thickness of the covering elastic member is in the range of 0.5 to 3 mm. If this thickness is too thin or too thick, the effects of the present invention tend to be small.

  As for the film thickness and area when the elastic body for coating covers the garter spring, as a result of various investigations, it is suitable for performing control with two-sidedness of restraint and release with respect to the movement in the X, Y and Z directions. As the physical properties, it is necessary to have a flexible and stretchable film. Therefore, the film thickness should be 0.5 to 3 mm and the coating area should be 1/2 to 1/4 of the outer surface of the garter spring. This is due to the conclusion that

  According to the present invention, it is possible to prevent the opening of the seal portion due to so-called stick slip, and it is possible to achieve a stable seal even when the sealed fluid pressure fluctuates, and to achieve a stable seal and a long life. A sealing device with a garter spring can be provided.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 is a perspective view of an essential part of a lip seal device according to an embodiment of the present invention.
FIG. 2 is a perspective view of a main part of the sealing device shown in FIG.
FIG. 3 is a perspective view of a garter spring,
4 is a perspective view of a main part of the garter spring shown in FIG.
FIG. 5 is a perspective view of an essential part of a garter spring with an elastic member for covering,
FIG. 6 is a front view of a garter spring with a covering elastic member,
FIG. 7 is a schematic sectional view of a test apparatus showing the effect of the sealing device according to the embodiment of the present invention,
8 to 12 are graphs showing the sealing characteristics of the sealing devices according to Examples and Comparative Examples of the present invention.

  As shown in FIG. 1, a lip seal device 10 according to an embodiment of the present invention has a seal body 1 that has a ring shape as a whole. The seal body 1 includes a ring-shaped base end portion 1a attached to a casing and the like, a support portion 1c having a bent cross section integrally formed on the inner peripheral side of the base end portion 1a, and an inner periphery of the support portion 1c. And a ring-shaped seal lip 1b integrally formed on the side. On the inner periphery of the seal lip portion 1b, a lip tip (seal portion) 4 having a sharp inner peripheral tip in the cross section is formed. The lip tip 4 slides with respect to the outer periphery of the rotating shaft 16 as shown in FIG.

  A spring groove 3 for fitting the garter spring 2 is formed along the longitudinal direction of the seal lip portion 1b on the back side (outer peripheral side) of the lip tip of the seal lip portion 1b. The seal body 1 including the base end portion 1a, the support portion 1c, and the seal lip portion 1b is integrally formed with a rubber material such as nitrile rubber or fluoro rubber, or a synthetic resin.

  As shown in FIGS. 1 and 2, a garter spring 2 is fitted inside the spring groove 3 so that the upper end of the spring groove 3 is exposed. The garter spring 2 is made of, for example, a metal such as spring steel, stainless steel, or hastelloy. As shown in FIG. 3, the garter spring 2 is connected in a ring shape as a whole.

  As shown in FIG. 4, the wire diameter d1 of the garter spring 2 is not particularly limited, but is, for example, about 0.8 to 1.4 mm. Further, the outer diameter Do of the garter spring 2 is substantially the same as the inner diameter of the spring groove 3 shown in FIG. 2, for example, about 4.0 to 7.0 mm. The inner diameter Di of the garter spring 2 is a value obtained by subtracting twice the wire diameter d1 from the outer diameter Do.

  In the present embodiment, as shown in FIGS. 1 and 2, the exposed portion of the garter spring 2 fitted in the spring groove 3 from the spring groove 3 is covered with the covering elastic member 8. Yes. The covering elastic member 8 not only covers a part of the entire circumference of the garter spring 2 but also integrally covers the front edge portion 5 and the rear edge portion 6 formed on both sides of the spring groove 3. . In FIG. 2, the Z direction is the longitudinal direction (circumferential direction) of the garter spring 2, and the X direction perpendicular thereto is the axial direction of the rotating shaft 16 shown in FIG. The direction is the radial direction of the rotating shaft 16.

  5 and 6, the range θ covered by the covering elastic body 8 with respect to the outer periphery of the garter spring 2 is substantially the same as the range of the opening of the spring groove 3 shown in FIG. On the other hand, it is preferably ½ to ¼. In this embodiment, a partial range θ on the outer periphery of the garter spring 2 is continuously covered with the covering elastic body 8 along the longitudinal direction Z of the garter spring 2.

  The covering elastic body 8 is made of a rubber material different from the material constituting the seal body 1, and is preferably made of a rubber material superior in flexibility to the material constituting the seal body 1. For example, when the elongation of the material constituting the seal body 1 (specified in JIS K6251) is 100 to 150%, the elongation of the covering elastic body 8 is about 1 to 4 times larger, preferably 100% or more. More preferably, it is 300% or more, and particularly preferably 600% or more.

  The thickness with which the covering elastic body 8 covers a part of the outer peripheral surface of the garter spring 2 is not particularly limited, but is preferably in the range of 0.5 to 3 mm. The covering elastic body 8 may enter from the outer peripheral surface of the garter spring 2 to the inner peripheral surface to cover the garter spring 2.

  Although it does not specifically limit as a method for covering a part of outer peripheral surface of the garter spring 2 with the coating | coated elastic body 8, For example, the adhesion system and the baking system are illustrated. In the bonding method, as shown in FIGS. 1 and 2, after the garter spring 2 is fitted into the spring groove 3, a curable adhesive is applied to the outer peripheral surface of the garter spring 2 exposed from the spring groove 3. Apply and then dry and cure the adhesive. As a result, the portion where the garter spring 2 is exposed to the spring groove 3 can be completely covered with the covering elastic body 8 made of the hardened adhesive.

  Examples of the curable adhesive include room temperature curable adhesive, two-component mixed adhesive, ultraviolet curable adhesive, and thermosetting adhesive, but are not particularly limited. The material of the adhesive is selected after it is cured and is more flexible than the seal body 1 and has a large elongation characteristic. Further, as the adhesive constituting the covering elastic body 8, it is preferable to select a material having good adhesiveness for both the garter spring (metal) 2 and the seal body (rubber) 1.

  In the baking method, for example, an unvulcanized rubber-like elastic sheet for covering rubber is separately prepared, and this sheet covers a predetermined range θ along the entire circumference of the garter spring 2 along the longitudinal direction, and this is baked on the garter spring 2. A covering elastic body 8 is formed to cover a part of the garter spring 2. If the baking process is before fitting the garter spring 2 to the spring groove 3, the covering elastic body 8 adheres only to the garter spring 2, but the garter spring 2 is fitted to the spring groove 3. It is preferable that the seal main body 1 is integrated and baked later. This is because the portion where the garter spring 2 is exposed to the spring groove 3 can be completely covered with the covering elastic body 8. The method for selecting the material of the rubber-like elastic sheet in the baking method is the same as in the bonding method.

  In the lip seal device 10 according to the present embodiment, the garter spring 2 partially covered with the covering elastic member 8 restrains the peristaltic motion of the garter spring 2 due to stick slip. Further, since the portion of the garter spring 2 that contacts the spring groove 3 is not constrained, the degree of freedom that can follow the vibration of the lip tip 4 is given, but the significant movement is limited. As a result, the functionality as the sealing device 10 is improved, and the opening at the sliding contact surface of the lip tip 4 due to a stick slip can be suppressed. Further, by making it difficult for the opening on the sliding surface to occur, the sealing performance can be stabilized and a longer life can be expected.

  Moreover, in this embodiment, it has the effect which suppresses the increase in a shaft clamping force low with respect to the increase in the pressure of the to-be-sealed body 7. FIG. This prevents the covering elastic body 8 and the upper surface portion of the garter spring 2 from joining, and the elastic body 8 is filled in the upper gap of the garter spring 2, thereby preventing the garter spring 2 from trying to shrink, This is because a reverse force that counteracts the increase in the sealed body pressure is generated, and the increase in the tightening force on the shaft is gradually reduced.

  That is, in the present embodiment, the pressure fluctuation of the sealed body 7 does not immediately act on the sliding contact surface of the lip tip 4, but the pressure fluctuation is primarily captured by the covering elastic member 8 and is buffered. Then, the pressure that is gradually reduced is transmitted to the slidable contact surface of the lip tip 4. For this reason, it becomes a binding force lip seal which is insensitive to fluctuations in pressure, and the sealing performance is stabilized.

  Further, in the present embodiment, by forming the covering elastic member 8 on the portion exposed on the outer periphery of the garter spring 2 with respect to the spring groove 3, the garter spring corrosion resistance can be improved by a relatively inexpensive and easy method. Can be maintained.

  Furthermore, in this embodiment, the outer diameter surface of the garter spring 2 exposed from the spring groove 3 is covered with the covering elastic member 8, and the seal body 1 and the garter spring 2 are covered with the covering elastic member. 8 is integrated. For this reason, the seal body 1 and the garter spring 2 are joined and integrated by the covering elastic member 8 while fixing the inner diameter of the seal body 1 on a liner (not shown) of a seal ring size of a predetermined dimension in advance. The stability of the seal dimension (inner diameter of the lip tip 4) is ensured.

The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.
For example, the seal device with a garter spring according to the present invention is not limited to the specific structure of the lip seal device 10 of the illustrated embodiment, and can be applied to other lip seal devices or other seal devices.

Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples.
Example 1

  A seal body 1 and a garter spring 2 having the shapes shown in FIGS. 1 and 2 were prepared, and the surfaces of the garter spring 2 and the seal body 1 were washed with a solvent to remove dirt, oil, and the like. Next, the garter spring 2 was fitted into the spring groove 3 of the seal body 1 and placed on a liner having a predetermined dimension corresponding to the seal shaft diameter.

  In this state, as shown in FIG. 2, a room temperature curable silicone rubber system solution is applied to the surface of the garter spring 2 exposed from the spring groove 3, the front edge portion 5 and the rear edge portion 6 with a smooth surface. It was applied at a thickness of 0.5 to 3 mm. Thereafter, the seal body 1 was left for a predetermined time, and after the adhesive film was dried and solidified, the seal body 1 was removed from the liner.

  There are various types of room temperature curing type silicone rubber system materials, and the properties are 50 to 600% elongation, tensile strength is about 1 to 3 MPa, and the operating temperature range is −50 to + 250 ° C., and the rubber elasticity is not lost. The material is known.

  The following evaluation tests were conducted in order to compare and investigate the sealing stability of the conventional garter spring sealing method, the garter spring method with an elastic material for coating, and the coating area and coating properties (elongation) of the elastic coating for coating. It was. The thickness of the covering elastic coating was 1 to 1.5 mm. The test apparatus is shown in FIG.

As shown in FIG. 7, an air source, a filter, a regulator, and a flow control valve are provided in a seal chamber 17 between the tester bearing side lip seal device 9 and the test lip seal device 10 held in a seal casing 12 of the test device. Initially set air was allowed to flow through the air supply pipe 18 from a pneumatic control unit 19 equipped with these (not shown). The initial set pressure in the pneumatic control unit 19 was 40 × 10 ⁻⁴ MPa. The pressure in the seal chamber 17 was measured with a pressure sensor through the vent pipe 20. Bearing oil 21 was sealed at a pressure of 0.09 to 0.12 MPa on the front side of the tester bearing side lip seal device 9. In FIG. 7, reference numeral 22 denotes the atmosphere, reference numeral 11 denotes a rotary testing machine bearing flange, reference numeral 13 denotes a casing retainer, and reference numeral 16 denotes a rotating shaft.
Test conditions

The test was performed under completely unlubricated conditions, with no air supply for 30 minutes from the start of the test, and rotated at a shaft speed of 270 rpm. After 30 minutes, 40 × 10 ⁻⁴ MPa (0.004 Mpa) of pressurized air was flowed into the seal chamber 17, and the number of pressure drops within 2 hours and the sliding heat generation temperature of the lip tip 4. Were measured for comparative evaluation.

  A thermocouple wire for temperature measurement was embedded at a location 2 mm outside the sliding contact surface of the lip tip 4 of the lip seal device 10 for test, and the sliding heat generation temperature was measured.

Other conditions were as follows.
(1) Liner diameter (outer diameter of rotating shaft 16); φ355mm,
(2) Lip inner diameter: φ348mm,
(3) Outer diameter Do of garter spring 2: φ4 mm, wire diameter d1: 0.8 mm,
(4) The peripheral speed of the rotating shaft 16; 5.0 m / s (270 rpm),
(5) Shaft eccentricity; TIR 0.5mm,
(6) Casing eccentricity; TIR 0.1 mm or less,
(7) Air pressure: 0.004 MPa (however, 30 minutes after the start of the rotation test)
(8) Seal chamber: Completely dry.
Test 1

  Test 1 corresponds to the conventional method, and the covering elastic body 8 shown in FIGS. 1 and 2 was not formed at all. FIG. 8 shows a change curve diagram of the seal chamber pressure and the lip tip temperature in Test 1. FIG.

Table 1 shows numerical values obtained by reading the number of times of pressure drop in the seal chamber, the maximum temperature at the tip of the lip, and the arrival time thereof from the graph of Test 1 shown in FIG. In addition, the reading of the number of times of pressure reduction in the seal chamber was counted as one when the pressure dropped in a range of 10 × 10 ⁻⁴ MPa (0.001 Mpa) or more.

As shown in FIG. 8 and Table 1, the maximum temperature of the lip tip is high and the time to reach the maximum temperature is short. The number of seal pressure drops was also high. It was also confirmed that stick-slip occurred frequently and the garter spring moved significantly (moving about 45 mm). Further, the thermocouple wire embedded in the lip surface was broken in about 90 minutes due to vibration.
Test 2

  In Test 2, the garter spring was coated all around with a room temperature curable silicone rubber adhesive a having an elongation after curing of 600% as an adhesive, and the garter spring was joined to the spring groove all around. The lip seal device was assembled and the same test as in Test 1 was performed. The results are shown in Table 1 and FIG.

A material with large elongation is used as the elastic body for the coating layer, but since the garter spring 2 is fixed on the entire surface, all the movements in the X, Y, and Z directions are sealed. Low but found to be the second worst after Test 1 when compared to other comparative samples.
Test 3

  In Test 3, the adhesive layer a having an elongation of 600% was used as a film characteristic after curing to cover a range θ of 1/3 of the entire circumference of the garter spring 2, and the film after curing was a spring groove. A test similar to the test 1 was performed using a lip seal device in which the front edge portion 5 and the rear edge portion 3 of 3 were also integrally covered. The results are shown in Table 1 and FIG.

As shown in Table 1 and FIG. 10, in Test 3, unlike Tests 1 and 2, it was confirmed that the maximum lip temperature was low and the number of seal pressure drops was low. This is probably because the peristaltic movement in the Z direction is hindered, but the fine vibrations in the X and Y directions are absorbed.
Test 4

  In Test 4, the adhesive film b having a stretch of 300% was used as a film characteristic after curing, and the range θ of 1/3 of the entire circumference of the garter spring 2 was covered. A test similar to the test 1 was performed using a lip seal device in which the front edge portion 5 and the rear edge portion 3 of 3 were also integrally covered. The results are shown in Table 1 and FIG.

As shown in Table 1 and FIG. 11, in Test 4, unlike Tests 1 and 2, it was confirmed that the maximum lip temperature was low and the number of seal pressure drops was also low. This is probably because the peristaltic movement in the Z direction is hindered, but the fine vibrations in the X and Y directions are absorbed. However, Test 4 is slightly inferior to Test 3.
Test 5

  In Test 5, the adhesive c having an elongation of 80% was used as a film characteristic after curing, and the range θ of 1/3 of the entire circumference of the garter spring 2 was covered. A test similar to the test 1 was performed using a lip seal device in which the front edge portion 5 and the rear edge portion 3 of 3 were also integrally covered. The results are shown in Table 1 and FIG.

As shown in Table 1 and FIG. 12, it was confirmed that both the maximum lip temperature and the number of seal pressure drops were not good in Test 2 in the film-attached garter spring.
Evaluation

  From these data, it can be seen that the film area covering the garter spring, the bonding method and the film characteristics of the film have a large effect on the lip seal, and by using these in combination, a stable sealing performance is ensured. I think.

  Further, a garter spring-embedded integrated lip in which a garter spring is embedded in a spring groove at the time of rubber molding is known. However, as in Test 2, this completely deprives the degree of freedom of the spring. It is expected that the pressure drop is larger than that of the first embodiment.

  The present invention is capable of preventing the opening of the seal portion due to so-called stick-slip, and also achieves a stable seal even when the sealed fluid pressure fluctuates, thereby achieving a stable seal and a long life. It can be applied to a sealing device or the like.

FIG. 1 is a perspective view of an essential part of a lip seal device according to an embodiment of the present invention. FIG. 2 is a perspective view of a main part of the sealing device shown in FIG. FIG. 3 is a perspective view of the garter spring. 4 is a perspective view of a main part of the garter spring shown in FIG. FIG. 5 is a perspective view of a main part of a garter spring with a covering elastic member. FIG. 6 is a front view of a garter spring with a covering elastic member. FIG. 7 is a schematic cross-sectional view of a test apparatus showing the effect of the sealing apparatus according to the embodiment of the present invention. FIG. 8 is a graph showing the sealing characteristics of the sealing device according to the comparative example of the present invention. FIG. 9 is a graph showing the sealing characteristics of the sealing device according to the comparative example of the present invention. FIG. 10 is a graph showing the sealing characteristics of the sealing device according to the example of the present invention. FIG. 11 is a graph showing the sealing characteristics of the sealing device according to the example of the present invention. FIG. 12 is a graph showing the sealing characteristics of the sealing device according to the comparative example of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Seal main body 2 ... Garter spring 3 ... Spring groove 4 ... Lip tip 5 ... Front edge part 6 ... Rear edge part 7 ... Sealed body 8 ... Covering elastic body 9 ... Test machine bearing side lip seal device 10 ... Lip seal Apparatus 11 ... Flange tester bearing side flange 12 ... Seal casing 13 ... Casing retainer 16 ... Rotating shaft 17 ... Seal chamber 18 ... Air supply pipe 19 ... Air pressure control unit 20 ... Pressure sensor vent pipe 21 ... Bearing oil 22 ... Air

Claims (5)

A seal device with a garter spring having a seal body and a ring-shaped garter spring attached to a back surface position of a seal portion in the seal body,
A part of the outer diameter surface of the garter spring is covered with a covering elastic member made of a material different from that of the seal body.   In the spring groove formed at the back surface position of the seal portion in the seal body, the garter spring is fitted so that a part of the entire circumference of the outer diameter surface is embedded and the rest is exposed, The sealing device according to claim 1, wherein an outer diameter surface of the garter spring exposed from the spring groove is covered with the covering elastic member.   The seal according to claim 1 or 2, wherein 1/2 to 1/4 of the entire circumference of the outer diameter surface of the garter spring is entirely or partially covered with the covering elastic member. apparatus.   The sealing device according to claim 1, wherein the sealing device is covered with the covering elastic member continuously or intermittently along an axial direction of the garter spring. The sealing device according to any one of claims 1 to 4, wherein a thickness of the covering elastic member is in a range of 0.5 to 3 mm.

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