JP6594217B2 - Shaft seal device - Google Patents

Description

  In the present invention, an in-machine mechanical seal and an atmosphere-side mechanical seal are disposed between a rotating shaft and a seal housing through which a shaft passes, and an in-machine area and an atmosphere area are formed between both mechanical seals. And a shaft seal device in which the in-machine region is a corrosive fluid region, and the seal fluid region is a non-corrosive fluid region having a higher pressure than the in-machine region.

  For example, in the shaft seal device disclosed in Patent Document 1 or Patent Document 2, an in-machine mechanical seal and an atmosphere-side mechanical seal are disposed between the rotary shaft and a seal housing through which the rotary shaft penetrates. When the fluid in the in-machine region (sealed fluid) is a corrosive fluid, it is configured to shield the region and the atmospheric region through a sealing fluid region formed between both mechanical seals. By supplying the fluid region with a sealing fluid that is a non-corrosive fluid at a higher pressure than the in-machine region (and the atmospheric region), that is, by keeping the sealing fluid region at a higher pressure than the in-machine region, It is intended to prevent leakage.

  Thus, in the in-machine mechanical seal in such a shaft seal device, as shown in FIG. 1 of Patent Document 1 or FIG. 2 of Patent Document 2, one of the rotary shaft and the seal housing through which this shaft passes is fixed on the fixed side O. A fixed sealing ring fitted and fixed via a ring, a movable sealing ring fitted and held on the other side of the rotary shaft and the seal housing via a movable side O-ring so as to be movable in the axial direction, and this into a fixed sealing ring And a spring member that presses and urges, so as to shield and seal the in-machine region that is a corrosive fluid region and the seal fluid region that is a higher pressure non-corrosive fluid region by the relative rotation action of both seal rings. The fixed-side O-ring is an O-ring loading space having a constant radial width formed between opposed circumferential surfaces of a fixed sealing ring and a rotary shaft or a seal housing which is a fixing member for fitting and fixing the fixed sealing ring. To, and is loaded in a state of being restricted by the locking portion formed of pressed and moved to the fixed member by the high-pressure sealing fluid. That is, in the in-machine mechanical seal of the shaft seal device shown in FIG. 1 of Patent Document 1, the rotary shaft as a fixing member is configured to include a shaft body and a sealing ring holder fixed to the shaft body. In addition, the inner peripheral portion of the fixed seal ring is fitted to the seal ring holder, and the fixed-side O-ring is sealed in the O-ring loading space having a constant radial width formed between the opposed peripheral surfaces of the fitting portion. It is loaded in a state in which the pressing movement due to the pressure is blocked by the locking portion formed in the sealing ring holding portion, and the fitting portion between the rotating shaft and the fixed sealing ring is sealed (secondary seal). Further, in the in-machine mechanical seal of the shaft seal device shown in FIG. 2 of Patent Document 2, the outer peripheral portion of the fixed sealing ring is fitted to the seal housing which is a fixing member, and the opposite peripheral surface of the fitting portion is fitted. The fixed O-ring is fixed to the seal housing by loading the fixed-side O-ring into the formed O-ring loading space with a constant radial width in a state where the pressing movement due to the pressure of the seal fluid is blocked by the locking portion formed on the seal housing. The fitting part with the seal ring is sealed (secondary seal).

JP 2011-007239 A JP 2011-099532 A JP 2003-185030 A

  However, in any in-machine mechanical seal of any shaft seal device, when the fluid in the low pressure region (sealed fluid) is a corrosive fluid, the stationary O-ring is fixed by the sealing fluid at a higher pressure than the fluid to be sealed. Although it is pressed against the locking part formed on the surface, it is always in contact with the corrosive fluid. May decrease.

  When the fluid to be sealed is a fluid that swells the O-ring, as disclosed in Patent Document 3, the cross-section substantially V made of corrosion-resistant plastic such as polytetrafluoroethylene is used instead of the fixed-side O-ring. A letter-shaped annular seal member (consisting of a main body portion and an inner lip portion and an outer lip portion that extend in an inclined manner in the inner and outer circumferential directions and elastically press against the opposing circumferential surface, and is generally called a V-ring. However, even if such a V-ring is in contact with a corrosive fluid over a long period of time, it does not cause corrosion damage like an O-ring. Therefore, the sealing function is low compared to the O-ring and lacks reliability. The fixed sealing ring and the fixing member (fitting shaft or seal housing) for fitting and fixing the sealing ring It is hard to say that those that can sufficiently seal (secondary seal) between.

  The present invention has been made in view of the above points, and a shaft capable of exhibiting a good shaft sealing function over a long period of time without causing corrosion damage to the stationary O-ring of the in-machine mechanical seal that contacts the corrosive fluid. The object is to provide a sealing device.

  In the present invention, an in-machine mechanical seal and an atmosphere-side mechanical seal are disposed between a rotating shaft and a seal housing through which a shaft passes, and an in-machine area and an atmosphere area are formed between both mechanical seals. The shaft sealing device is configured so as to be shield-sealed through the seal, and the in-machine region is a corrosive fluid region and the seal fluid region is a non-corrosive fluid region having a higher pressure than the in-machine region. Therefore, in particular, the in-machine mechanical seal is fitted and fixed to one of the rotating shaft and the seal housing via a fixed O-ring and the movable shaft O to the other of the rotating shaft and the seal housing via a movable O-ring. A movable sealing ring fitted and held so as to be movable in the axial direction and a spring member that presses and urges the sealing ring to the fixed sealing ring are provided. The fixed-side O-ring is formed between opposed peripheral surfaces of a fixed sealing ring and a rotary shaft or a seal housing which is a fixing member for fitting and fixing the fixed sealing O-ring. The O-ring loading space having a constant radial width is loaded in a state in which the pressing movement due to the pressure in the sealing fluid region is regulated by a locking portion formed on the stationary member, and the stationary-side O-ring is loaded into the O-ring loading space. An inner peripheral lip portion and an outer peripheral lip portion which are arranged between the main body portion and the locking portion and extend in an inclined manner toward the inner and outer peripheral directions toward the main body portion and the fixed-side O-ring and elastically press against the opposing peripheral surface. It is proposed that an annular seal member made of corrosion resistant plastic made of

  In such a shaft seal device, the annular seal member is arranged in the O-ring loading space between the fixed-side O-ring and the locking portion, and the annular seal member is arranged in parallel with the inner and outer peripheral lip portions facing the fixed-side O-ring. A plurality can be loaded in a state. Moreover, it is preferable to use the thing made from a polytetrafluoroethylene as said cyclic | annular sealing member.

  In the shaft seal device of the present invention, the fixed side O-ring of the in-machine mechanical seal is blocked from contact with the corrosive fluid in the in-machine region by the annular seal member made of corrosion-resistant plastic. Will not be corroded by contact with corrosive fluids. In addition, the sealing force by the inner and outer peripheral lip portions of the annular seal member is increased by the fixed side O-ring biting between the inner and outer peripheral lip portions due to the pressure in the sealing fluid region higher than the in-machine region. The contact between the ring and the corrosive fluid is reliably blocked by the annular seal member, and the sealing function by the fixed-side O-ring is satisfactorily exhibited over a long period. Therefore, according to the shaft seal device of the present invention, even when the sealed fluid is a corrosive fluid, a good shaft seal function can be exhibited over a long period of time.

FIG. 1 is a cross-sectional view showing an example of a shaft seal device according to the present invention. FIG. 2 is a cross-sectional view corresponding to FIG. FIG. 3 is an enlarged detailed view showing the main part of FIG. FIG. 4 is a cross-sectional view showing an essential part of FIG. FIG. 5 is a cross-sectional view of a main part corresponding to FIG. 3 showing a modification of the shaft seal device according to the present invention. FIG. 6 is a cross-sectional view of the main part showing another modification of the shaft seal device according to the present invention.

  The form for implementing this invention is demonstrated concretely based on FIGS. 1-4. 1 is a cross-sectional view showing an example of a shaft seal device according to the present invention, FIG. 2 is a cross-sectional view corresponding to FIG. 1 showing a cross-section different from FIG. 1, and FIG. 3 is an enlarged view of the main part of FIG. FIG. 4 is a cross-sectional view showing a main part of FIG.

  The shaft seal device shown in FIGS. 1 and 2 is mounted on a rotary device such as a pump or a stirrer that handles a corrosive fluid (for example, ethylbenzene, styrene, etc.). An in-machine mechanical seal 3 and an atmosphere-side mechanical seal 4 are arranged between the seal housing 2 and the mechanical seal 3 so that an in-machine area A that is a corrosive fluid area and an atmospheric area B that is an out-of-machine area. , 4 is a double seal configured to be shield-sealed through a seal fluid region C which is a non-corrosive fluid region. In the following description, front and rear mean the left and right in FIGS.

  As shown in FIGS. 1 and 2, the seal housing 2 includes a main body portion 2a provided in the housing of the rotating device and an annular flange portion 2b attached to an end portion (front end portion) on the atmosphere region side. The inner peripheral portions of both portions 2a and 2b are circular, and the rotating shaft 1 penetrates concentrically. As shown in FIGS. 1 and 2, the rotary shaft 1 includes a shaft main body 1 a and a sleeve 1 b that is positioned in the seal housing 2 and fixedly inserted therethrough.

  As shown in FIGS. 1 and 2, the in-machine mechanical seal 3 includes a fixed sealing ring 6 fitted and fixed to the seal housing 2 via a fixed O-ring 5 and a rotary shaft 1 via a movable O-ring 7. A movable seal ring 8 fitted and held so as to be movable in the axial direction (movable in the front-rear direction) and a spring member 9 (see FIG. 2) for pressing and urging the ring to the fixed seal ring 6 are provided. This is an end surface contact type mechanical seal configured to shield and seal the in-machine region A and the seal region C by the relative rotational sliding contact action of the sealed end surfaces 6a and 8a which are the opposed end surfaces of 6 and 8.

  As shown in FIG. 3, the fixed sealing ring 6 is connected to a sealing end surface forming portion 6b having a tip end surface (front end surface) formed as a sealing end surface 6a which is a smooth annular plane orthogonal to the axis, and an intermediate portion 6c connected thereto. It is an annular body made of carbon composed of an O-ring holding portion 6d, and is loosely fitted to the sleeve 1b of the rotating shaft 1, so that the base end portion of the seal housing 2, that is, the base end portion (rear end portion) of the main body portion 2a. ) Is fitted and fixed via a fixed-side O-ring 5. The outer diameter of the intermediate portion 6c of the fixed seal ring 6 is set slightly smaller than the inner diameter of the base end portion of the main body portion 2a of the seal housing 2, and the outer diameter of the O-ring holding portion 6d is smaller than the outer diameter of the intermediate portion 6c. Between the opposing peripheral surfaces of the base end portion of the main body portion 2a of the seal housing 2 and the O-ring holding portion 6d of the fixed sealing ring 6, that is, the inner peripheral surface of the base end portion of the main body portion 2a of the seal housing 2. An annular O-ring loading space 10 having a constant radial width is formed between a certain housing-side sealing surface 2c and a sealing ring-side sealing surface 6e that is the outer peripheral surface of the O-ring holding portion 6d of the fixed sealing ring 6. Yes. As shown in FIG. 1, the fixed sealing ring 6 has a drive pin 2d protruding from the main body 2a of the seal housing 2 in a recess 6f formed at the base end (rear end) of the O-ring holding portion 6d. As a result, relative rotation with respect to the seal housing 2 is prevented.

  As shown in FIG. 3, the fixed-side O-ring 5 is loaded in the O-ring loading space 10 in a radially compressed state, and is elastically pressed against the housing-side seal surface 2c and the sealing ring-side seal surface 6e. By doing so, the fitting part of the seal housing 2 and the fixed sealing ring 6 is sealed (secondary seal).

  As shown in FIG. 3, the main body 2 a of the seal housing 2 is provided with an annular locking portion 2 e that protrudes into the base end portion (rear end portion) of the O-ring loading space 10. From the O-ring loading space 10 is regulated. That is, the fixed-side O-ring 5 enters the O-ring loading space 10 in a state in which the pressing movement (axial movement) in the in-machine area A (rearward) due to the pressure in the sealing fluid area C is restricted by the locking portion 2e. It is loaded.

  As shown in FIGS. 1 and 2, the movable seal ring 8 is arranged on the atmospheric region side (front side) with respect to the fixed seal ring 6, and can move in the axial direction through the movable side O-ring 7 to the sleeve 1 b of the rotary shaft 1. Is held fitted. The movable seal ring 8 is made of a metal that fits and fixes the seal ring body 8b made of a material harder than the constituent material of the fixed seal ring 6 (in this example, cemented carbide) and the front end (rear end). It is an annular body composed of a seal ring holder 8c (made of titanium in this example) and a drive collar 8d connected to the base end thereof, and the front end surface (rear end surface) of the seal ring main body 8b is orthogonal to the axis. The sealing end face 8a is a smooth annular plane that contacts the sealing end face 6a of the fixed sealing ring 6. The outer diameter of the sealing end face 8 a of the movable sealing ring 8 is larger than the outer diameter of the sealing end face 6 a of the fixed sealing ring 6, and the inner diameter of the sealing end face 8 a of the movable sealing ring 8 is larger than the inner diameter of the sealing end face 6 a of the fixed sealing ring 6. It is set small. Further, as shown in FIG. 1, the movable seal ring 8 is inserted and engaged with a drive pin 12 projecting from a drive collar 8d on a drive ring 11 which is disposed on the atmosphere region side (front side) and fitted and fixed to the sleeve 1b. By doing so, relative rotation with respect to the rotating shaft 1 is prevented while allowing axial movement within a predetermined range.

  As shown in FIGS. 1 and 2, the movable O-ring 7 is formed between the opposed peripheral surfaces of the base end portion (front end portion) of the seal ring holder 8 c of the movable seal ring 8 and the sleeve 1 b of the rotating shaft 1. The annular O-ring loading space 13 having a constant radial width is loaded, and the fitting portion between the movable sealing ring 8 and the rotary shaft 1 is sealed (secondary seal). The movable side O-ring 7 is movable in the axial direction within a range restricted by an annular step 8e formed on the inner peripheral middle portion of the seal ring holder 8c of the movable seal ring 8 and the drive collar 8d. The O-ring loading space 13 is loaded and pressed against the annular step 8e by the pressure in the seal fluid region C.

  The fixed O-ring 5 and the movable O-ring 7 are made of a corrosion-resistant elastic material such as fluoro rubber or Kalrez (registered trademark). In this example, both O-rings 5 and 7 are made of green, tweed and company. It is composed of Chemraz 505 manufactured by the company.

  As shown in FIGS. 1 and 2, the atmosphere-side mechanical seal 4 has the same structure as the machine-side mechanical seal 3, and is located on the atmosphere region side (front side) from the machine-side mechanical seal 3. And arranged in the opposite direction. That is, the atmosphere side mechanical seal 4 has a symmetrical structure with the in-machine mechanical seal 3 with the drive ring 11 interposed therebetween, and is a fixed sealing ring fitted and fixed to the flange portion 2b of the seal housing 2 via the O-ring 15. 16 and the movable seal ring 18 fitted and held so as to be movable in the axial direction (movable in the front-rear direction) via the O-ring 17 to the sleeve 1b of the rotary shaft 1 and a spring member for pressing and urging the movable seal ring 18 to the fixed seal ring 16 9, and is configured to shield and seal the air region B and the seal region C by the relative rotational sliding contact action of the sealed end surfaces 16 a and 18 a which are opposite end surfaces of the both seal rings 16 and 18. It is a mechanical seal. In this example, as shown in FIG. 2, the spring member 9 is constituted by a coil spring that passes through the drive ring 11 and is loaded between the movable sealing rings 8 and 18 of the two mechanical seals 3 and 4, and both the movable sealing members are sealed. A common biasing member that presses and biases the rings 8 and 18 to the fixed sealing rings 6 and 16 is used. Both O-rings 15 and 17 are made of fluororubber.

  In the seal housing 2, as shown in FIG. 1, the seal fluid supply channel 20 that supplies the seal fluid region C with the high-pressure seal fluid S from the in-machine region A and the seal fluid discharge that discharges the seal fluid S from the seal fluid region C are provided. A passage 21 is formed, and the sealing fluid S is circulated and supplied to the sealing fluid region C, and the sealing fluid region C is held at a higher pressure than the in-machine region A (and the atmospheric region B). As the sealing fluid S, a non-corrosive fluid that does not interfere with leakage into the in-machine region A and the atmospheric region B is used, and water is used in this example. As shown in FIG. 1, the flange portion 2b of the seal housing 2 opens to the base end side (front end side) of the stationary seal ring 16 of the atmosphere side mechanical seal 4 and is partitioned by the bush seal 22. 2, a quenching flow path 23 for supplying a quenching fluid Q (water in this example) to the atmospheric region portion is formed, and further, as shown in FIG. 2, a drain path for discharging drain D from the atmospheric region portion. 24 is formed.

  Thus, in the shaft seal device according to the present invention, even when the fluid in the in-machine region A (sealed fluid) is a corrosive fluid, the fixed side O-ring 5 of the in-machine mechanical seal 3 is corroded. In order to prevent this, the following measures are taken.

  That is, by loading the O-ring loading space 10 between the fixed-side O-ring 5 and the locking portion 2e and mounting the annular seal member 25 made of corrosion-resistant plastic, the fixed-side O-ring 5 is placed in the in-machine region A. It is devised not to contact the corrosive fluid.

  As shown in FIGS. 3 and 4, the annular seal member 25 extends in a slanting manner toward the inner and outer peripheral directions toward the main body portion 25 a and the fixed side O-ring 5, and the seal ring side seal surface 6 e and the housing side seal 2 c surface. This is an annular body having a substantially V-shaped cross section comprising an inner peripheral lip portion 25b and an outer peripheral lip portion 25c that are elastically pressed against each other, and has the same shape as the V-ring disclosed in Patent Document 3. In this example, polytetrafluoroethylene is used as a corrosion-resistant plastic that is a constituent material of the annular seal member 25.

  The annular seal member 25 is a state in which the inner and outer peripheral lip portions 25b and 25c are elastically deformed in a direction approaching each other as shown by a chain line from the natural state shown in the solid line in FIG. 4 (the state in which no radial load is applied). The O-ring loading space 10 is loaded. That is, as shown in FIG. 3, the annular seal member 25 has an inner peripheral lip portion 25 b that is elastically pressed against a seal ring side seal surface 6 e that is an outer peripheral surface of the O ring holding portion 6 d of the fixed seal ring 6 and has an outer periphery. In a state where the lip portion 25c is elastically pressed against the housing-side seal surface 2c which is the inner peripheral surface of the main body portion 2a of the seal housing 2, the main body portion 25a abuts on the locking portion 2e and the fixed-side O-ring 5 Is inserted into the O-ring loading space 10 in a state of slightly entering between the lip portions 25b and 25c.

  Thus, a pressing force in the direction of the annular seal member 25 acts on the fixed-side O-ring 5 by the pressure in the sealing fluid region C higher than the in-machine region A. The pressing-side force causes the fixed-side O-ring 5 to annularly seal. The gap between the two lip portions 25b and 25c of the member 25 is cut, whereby the space between the lip portions 25b and 25c of the annular seal member 25 is expanded in the radial direction. As a result, the pressing force of the inner peripheral lip portion 25b to the sealing ring side seal surface 6e and the pressing force of the outer peripheral lip portion 25c to the housing side seal surface 2c, that is, the sealing force by the inner and outer peripheral lip portions 25b and 25c are increased. become.

  Therefore, the sealing force by the annular seal member 25 itself is small as described at the beginning, that is, the pressure contact force to the seal surfaces 6e and 2c by the elastic force of the inner and outer peripheral lip portions 25b and 25c itself is small. However, since this pressure contact force (seal force) is increased by biting between the inner and outer peripheral lip portions 25b and 25c of the fixed side O-ring 5, an annular seal is formed between the fixed side O-ring 5 and the in-machine region A. It is securely sealed by the member 25, and the stationary O-ring 5 does not come into contact with the corrosive fluid that is the fluid in the in-machine region A. On the other hand, since the annular seal member 25 that contacts the corrosive fluid is made of a corrosion-resistant plastic (in this example, made of polytetrafluoroethylene), it is corroded even if it contacts the corrosive fluid for a long time. Never happen.

  As described above, the fixed-side O-ring 5 is blocked from contact with the corrosive fluid in the in-machine region A by the annular seal member 25 that is not corroded by contact with the corrosive fluid. Even when the fluid is a corrosive fluid, the fixed-side O-ring 5 is not corroded, and an appropriate sealing function (secondary sealing function) can be exhibited over a long period of time. Therefore, the shaft sealing function by the shaft sealing device is satisfactorily exhibited over a long period of time.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately improved and changed without departing from the basic principle of the present invention.

  For example, the number of the annular seal members 25 to be loaded in the O-ring loading space 10 is arbitrary, and a plurality of annular seal members are provided between the fixed-side O-ring 5 and the engaging portion 2e of the seal housing 2 as necessary. 25 can be loaded. When a plurality of annular seal members 25 are loaded in the O-ring loading space 10 as described above, as shown in FIG. 5, the inner and outer peripheral lip portions 25b and 25c are separated from the main body portion 25a. It arrange | positions so that it may parallel in the same attitude | position extended toward the fixed side O-ring 5. As shown in FIG. In this way, when the fixed-side O-ring 5 is pressed in the direction of the locking portion 2e by the pressure of the seal fluid region C, the all-annular seal member 25 is thereby pressed against the locking portion 2e. In the annular seal member 25 that contacts the fixed side O-ring 5, the fixed side O-ring 5 bites between the inner and outer peripheral lip portions 25b and 25c, and in each annular seal member 25 other than the annular seal member 25, When the main body 25a of the annular seal member 25 adjacent between the inner and outer peripheral lip portions 25b and 25c bites in, the sealed ring side seal surface 6e and the housing side seal surface 2c of the inner and outer peripheral lip portions 25b and 25c of the all annular seal member 25 are obtained. The pressure contact force is increased. Therefore, the sealing function by the annular seal member 25 is increased as the number of loaded members increases, and the contact between the fixed-side O-ring 5 and the corrosive fluid in the in-machine region A can be more reliably blocked.

  The annular seal member 25 can also be loaded into the O-ring loading space 13 of the movable O-ring 7 in the in-machine mechanical seal 3. That is, the annular seal member 25 is disposed between the movable side O-ring 7 and the annular step 8e of the movable seal ring 8 as shown in FIG. The ring 7 is loaded into the O-ring loading space 13 with the ring 7 biting between the inner and outer peripheral lip portions 25b and 25c. Even in this case, the sealing force by the inner and outer peripheral lip portions 25b and 25c of the annular seal member 25, that is, the inner and outer peripheral lips to the opposing peripheral surfaces of the holding body 8c of the movable sealing ring 8 and the sleeve 1b of the rotary shaft 1 The pressure contact force of the portions 25b and 25c is increased, so that the contact between the movable side O-ring 7 and the corrosive fluid in the in-machine region A can be blocked, and the movable side O-ring 7 is corroded by the contact with the corrosive fluid. Can be reliably prevented. Even in such a case, the number of the annular seal members 25 loaded in the O-ring loading space 13 is arbitrary.

  Further, the present invention is applied to a shaft seal device in which the fixing member for fitting and fixing the fixed sealing ring 6 in the in-machine mechanical seal 3 as described above is the seal housing 2, and as shown in Patent Document 1, A shaft seal device in which a fixed member for fitting and fixing a fixed seal ring in an inner mechanical seal is a rotating shaft, that is, a fixed seal ring and a seal housing in which the in-machine mechanical seal is fitted and fixed to the rotating shaft via a fixed-side O-ring. Further, the present invention can also be applied to a shaft seal device having a movable seal ring fitted and held so as to be movable in the axial direction through a movable O-ring.

DESCRIPTION OF SYMBOLS 1 Rotating shaft 1a Shaft main body 1b Sleeve 2 Seal housing 2a Main body 2b Flange 2c Housing side sealing surface 2d Drive pin 2e Locking part 3 Machine inner side mechanical seal 4 Atmospheric side mechanical seal 5 Fixed side O-ring 6 Fixed side sealing ring 6a Sealed end face 6b Sealed end face forming part 6c Intermediate part 6d O-ring holding part 6e Sealing ring side sealing face 6f Recessed part 7 Moving side O-ring 8 Movable sealing ring 8a Sealing end face 8b Sealing ring body 8c Holding body 8d Drive collar 9 Spring member 10 O Ring loading space 11 Drive ring 12 Drive pin 13 O ring loading space 15 O ring 16 Fixed seal ring 16a Sealed end face 17 O ring 18 Movable seal ring 18a Sealed end face 20 Seal fluid supply path 21 Seal fluid discharge path 22 Bush seal 23 Quenching Flow Path 24 Drain path 25 Annular seal member 25a Main body 25b Inner peripheral lip 25c Outer peripheral lip A Machine internal area (corrosive fluid area)
B Air region C Seal fluid region D Drain Q Quenching fluid S Seal fluid

Claims (2)

An in-machine mechanical seal and an atmosphere-side mechanical seal are arranged between the rotary shaft and the seal housing through which it passes, and the in-machine area and the atmosphere area are formed between both mechanical seals and shielded through the seal fluid area. In a shaft seal device configured to seal, wherein the in-machine region is a corrosive fluid region and the seal fluid region is a non-corrosive fluid region having a higher pressure than the in-machine region,
The in-machine mechanical seal is movable in the axial direction via a movable O-ring to the other of the rotary shaft and seal housing, and a fixed sealing ring fitted and fixed to one of the rotary shaft and seal housing via a fixed O-ring. A movable sealing ring fitted and held on the spring and a spring member that presses and urges the movable sealing ring toward the fixed sealing ring, so that the in-machine region and the sealing fluid region are shielded and sealed by the relative rotation action of both sealing rings. Configured,
The fixed-side O-ring is formed in a sealing fluid region in an O-ring loading space having a constant radial width formed between opposed peripheral surfaces of a fixed sealing ring and a rotary shaft or a seal housing which is a fixing member for fitting and fixing the fixed sealing ring. It is loaded in a state in which the pressing movement due to the pressure is regulated by a locking portion formed on the fixed member,
In the O-ring loading space, it is arranged between the fixed-side O-ring and the locking portion, and extends in an inward and outward direction toward the main body and the fixed-side O-ring so as to be elastic to the opposed peripheral surface. A shaft seal device, in which one annular seal member made of a corrosion-resistant plastic comprising an inner peripheral lip portion and an outer peripheral lip portion that are in pressure contact with each other is loaded. It said annular sealing member, characterized in der Rukoto made of polytetrafluoroethylene, shaft seal device according to claim 1.

Images