JP4954167B2 - Mechanical seal device for vertical shaft - Google Patents

Description

  The present invention relates to a vertical shaft mechanical seal device used for a shaft seal portion of equipment that requires cleaning and sterilization processing such as a stirrer for the pharmaceutical and food industries.

  A mechanical seal device is frequently used as a seal for rotating equipment, and an example of the rotating equipment is a stirrer that stirs fluid in a stirring tank. The stirrer includes a stirring tank, a stirring blade disposed in a lower portion of the stirring tank, and a vertical shaft (vertical rotating shaft) penetrating vertically through the bottom of the stirring tank for rotating the stirring blade. There are many things. A mechanical seal device is used as means for obtaining liquid tightness around the vertical axis. As this type of mechanical seal device, for example, one disclosed in Patent Document 1 is known.

  Mechanical seal devices are also used in the pharmaceutical and food industries, that is, in chemical and food agitators. In the fields of medicines and foods, from the viewpoint of hygiene, in many cases, aseptic processing is required for fluid agitation processing. In that case, in order to maintain the aseptic condition in the stirring tank, cleaning and sterilization are also required for the mechanical seal device.

  In a mechanical seal device having a seal portion in which a stationary seal ring and a rotary seal ring are pressed against each other in the axial direction, in order to clean and sterilize the contact surface of the seal portion, the stationary seal ring and the rotary seal ring are mutually connected. Although it is necessary to maintain it separated in the axial direction, the current mechanical seal device is not structured to do so. Therefore, conventional cleaning and sterilization of the mechanical seal device can only be performed by disassembling the mechanical seal device, which is very troublesome and troublesome.

  Therefore, as disclosed in Patent Document 2, by means called CIP (in-place cleaning) or SIP (in-place sterilization), that is, means for enabling cleaning and sterilization without disassembling the mechanical seal device. It has been proposed that the above-mentioned “troublesome and cumbersome” problem can be solved. That is, a sterile medium chamber is formed in a portion surrounding the mechanical seal portion, and the sterile medium chamber is sterilized with steam, or sterile water is introduced into the chamber to maintain a sterile state.

However, even if the technique according to Patent Document 2 is used, the contact surface of the seal portion is in a pressure contact state with a predetermined surface pressure, so that steam cannot reach the contact surface, and thus complete sterilization cannot be performed. This causes the same problem even when cleaning is performed instead of sterilization or in combination.
JP-A-7-103338 Japanese Patent Publication No. 6-098772

  An object of the present invention is to provide a vertical shaft mechanical seal device capable of performing reliable cleaning and sterilization on a seal portion in a mechanical seal, that is, a contact surface between a stationary seal ring and a rotary seal ring.

The invention according to claim 1 is a mechanical seal device for vertical shafts,
A rotary seal ring 4 that rotates integrally with a rotary shaft 1 having a vertical axis P;
A stationary seal ring 5 disposed below the rotary seal ring 4 in a state in which the seal housing 3 cannot rotate and is supported so as to be movable in the direction of the axis P of the rotary shaft 1;
A slide ring 6 that is a cylindrical member surrounding the rotating shaft 1 and is supported by the seal housing 3 so as to be reciprocally movable in a predetermined range in the vertical direction;
A coil spring for sealing 7 interposed between the slide ring 6 and the stationary sealing ring 5 in order to urge the stationary sealing ring 5 upward and press it against the rotary sealing ring 4;
A detaching coil spring 8 that urges the slide ring 6 downward to separate the stationary seal ring 5 from the rotary seal ring 4;
An air cylinder 9 for forcibly raising the slide ring 6 against the urging force of the detaching coil spring 8 so as to obtain a sealed state in which the stationary sealing ring 5 is pressed against the rotary sealing ring 4 by the sealing coil spring 7;
A liquid sealing mechanism 10 for supplying a cooling liquid to a sealing space 30 surrounded by the seal part S1 and the rotary shaft 1 when the stationary sealing ring 5 is pressed against the rotary sealing ring 4 and circulating the liquid while filling it; A first mechanical seal MS1, comprising:
And a second mechanical seal MS2 disposed below the first mechanical seal MS1,
The lower part of the slide ring 6 is formed into a shape having a large-diameter flange portion 6f spreading outward in the diameter and an annular piston portion 6p extending downward from the outer peripheral end of the large-diameter flange portion 6f,
An annular cylinder comprising the seal housing 3 and inner and outer sliding cylinder portions 24, 25 fitted to the inner and outer circumferences of the piston portion 6p, and an annular bottom wall portion 26 positioned below the piston portion 6p. Part 42 is formed,
An air supply / discharge passage 28 formed in the seal housing 3 for supplying and discharging air to and from the cylinder portion 42, the piston portion 6p, and a ring-shaped cylinder chamber cs surrounded by the cylinder portion 42 and the piston portion 6p. The air cylinder 9 is configured by
In order to promote the circulating action of the cooling liquid by the liquid sealing mechanism 10 in the slide ring 6 in the seal portion S1, the stationary seal ring 5 that protrudes upward from the slide ring 6 and surrounds the rotary shaft 1; Is equipped with a cylindrical damming portion 11 loosely fitted between,
The return path r of the coolant flowing down beyond the damming portion 11 is configured to include a space 34 formed below the large-diameter flange portion 6f in the seal housing 3. It is what.

  According to a second aspect of the present invention, in the vertical shaft mechanical seal device according to the first aspect of the present invention, the stationary seal ring is capable of maintaining a predetermined seal pressure by pressing the stationary seal ring 5 against the rotary seal ring 4. An auxiliary coil spring 13 for urging 5 downward is provided.

  According to a third aspect of the present invention, in the vertical shaft mechanical seal device according to the second aspect, the vertical movement amount of the slide ring 6 relative to the seal housing 3 between the seal coil spring 7 and the stationary seal ring 5. A cylindrical collar 12 supported by the slide ring 6 so as to be movable up and down by an amount e smaller than d is interposed, and a downward urging force by the auxiliary coil spring 13 is input to the collar 12. It is characterized by being.

According to a fourth aspect of the present invention, in the vertical shaft mechanical seal device according to any one of the first to third aspects, the damming portion 11 provided in the first mechanical seal MS1 has an upper end 11a. It is arranged to reach the seal portion S1 .

  According to the first aspect of the present invention, as will be described in detail in the section of the embodiment, the stationary seal ring is removed by releasing the air pressure of the air cylinder acting on the slide ring and moving it downward with the coil spring for removal. The seal can be opened by moving it downward and breaking the contact with the rotary seal ring. By making the seal open, it is possible to expose each contact surface of the rotary seal ring and the stationary seal ring forming the seal portion and perform clear cleaning and sterilization. Therefore, it is possible to sterilize the seal portion and its contact surface (sliding surface), which has been difficult until now, thereby increasing the reliability of the cleanliness of the device (stirring tank). As a result, it is possible to provide a vertical shaft mechanical seal device that can perform reliable cleaning and sterilization on the seal portion of the mechanical seal, that is, the contact surface between the stationary seal ring and the rotary seal ring.

  And since it is set as the tandem structure sealing apparatus which provides the 2nd mechanical seal under the 1st mechanical seal, the leak prevention from the rotating shaft circumference of a stirring tank can be performed completely, and more hygiene of chemicals, foods, etc. There is an advantage that it can sufficiently cope with severe fluids. Further, the piston portion for raising the slide ring with the air pressure is increased in diameter, so that a necessary pressure receiving area can be secured without difficulty and a good air cylinder operation is realized.

  Furthermore, as will be described in detail in the section of the embodiment, the function of a cylinder chamber that pushes the large-diameter flange portion upward is exerted by the pressure of the coolant existing in the space below the large-diameter flange portion. Therefore, there is also an advantage that the slide ring can be maintained at the sealing position even without air pressure acting on the piston portion. In other words, the first mechanical seal can be made to function by the liquid sealing mechanism, and the upward biasing of the slide ring by the air cylinder may be performed instantaneously at the start of the operation as the sealing device, and energy saving and rationalization are achieved. be able to.

  According to the second aspect of the present invention, since the auxiliary coil spring always urges the stationary sealing ring downward, it is possible to facilitate the downward movement of the stationary sealing ring when switched to the seal open state. It is possible to obtain the seal open state by the downward movement of 5 more reliably. In addition, the auxiliary coil spring can also exert a function of pressing and stabilizing the stationary sealing ring so as not to wobble during conveyance of the mechanical seal device.

  According to the invention of claim 3, the opening amount w of the seal portion accompanying the downward movement of the slide ring is a value obtained by subtracting the vertical movement amount e of the slide ring of the collar from the vertical movement amount d of the slide ring with respect to the seal housing. , W = de (see FIG. 2). As a result, the slide ring can be moved up and down with a sufficient stroke (movement amount d) so that the position can be clearly switched, while the opening amount (opening amount W) of the seal portion is a small dimension suitable for cleaning and sterilization. There is an advantage that it can be set.

  According to the invention of claim 4, the liquid sealing mechanism having the cylindrical damming portion whose upper end reaches the seal portion allows the cooling liquid to circulate vigorously through the sealing space portion, and at the top as the mechanism. A sufficient amount of coolant is also distributed to the seal portion (the seal portion of the first mechanical seal). Therefore, it is possible to sufficiently cool the seal portion located at the upper end portion of the apparatus, which is usually difficult to cool, while providing a cylindrical damming portion that is simple and almost free of cost, making it more rational and economical. A vertical mechanical seal device can be provided.

  Embodiments of a vertical shaft mechanical seal device according to the present invention will be described below with reference to the drawings. 1 is a cross-sectional view showing the structure of a vertical shaft mechanical seal device in a sealing action state, FIG. 2 is a cross-sectional view in an open state, FIG. 3 is an enlarged cross-sectional view of the first mechanical seal in FIG. It is sectional drawing which shows the mechanical seal apparatus for vertical shafts by.

[Example 1]
1 and 2 show a vertical shaft mechanical seal device A according to a first embodiment. This mechanical seal device A is configured to have a tandem structure in which a first mechanical seal MS1 and a second mechanical seal MS2 are arranged above and below a rotary shaft (vertical shaft) 1 having a vertical axis P. As an example, the mechanical seal device A is used for a stirrer (not shown), and the rotating shaft 1 is disposed vertically through a seal housing 3 connected to the lower end of the agitation tank 2, and its upper end. The part is equipped with a stirring blade (not shown).

  The seal housing 3 includes a mounting flange 3A that is bolted to the agitation tank 2, an upper flange 3B that is bolted to the upper side thereof, an intermediate flange 3C that is bolted to the lower side of the mounting flange 3A, and an intermediate flange 3C that is below the intermediate flange 3C. A lower end flange 3D that is bolted to the side, and an inner flange 3E that is disposed on the inner side of the intermediate flange 3C and on the upper side of the lower end flange 3D. The first mechanical seal MS1 is configured to extend over the mounting, upper end, middle, and inner flanges 3A to 3C, 3E and the rotating shaft 1, and the second mechanical seal MS2 extends to the lower end flange 3D and the rotating shaft 1. Configured.

  As shown in FIGS. 1 and 2, the first mechanical seal MS1 includes a first rotary seal ring 4, a first stationary seal ring 5, a slide ring 6, a seal coil spring 7, a release coil spring 8, and an air. The cylinder 9, the liquid sealing mechanism 10, the damming unit 11, the collar 12, and the auxiliary coil spring 13 are configured to directly seal the inside of the stirring tank (stirring can) 2. The first rotary seal ring 4 made of a material such as Sic is provided with a front end flange portion 14a of the first sleeve 14 that is externally fitted to the rotary shaft 1 in an integrally rotated state, and a front end flange portion 14a that is externally fitted to the rotary shaft 1. It is formed in an annular shape that is sandwiched between bolt-connected upper end flanges 15 and integrally rotates with the rotation shaft.

  The first stationary seal ring 5 made of a material such as Sic is fitted into the upper end flange 3B so as to be slidable up and down, and a working ring 16 is fitted and integrated at the lower end thereof. The working ring 16 made of a material such as titanium is relatively vertically movable to a cylindrical collar 12 positioned below the working ring 16 and is fitted non-rotatably by a pin 17 implanted in the collar 12. Yes. In other words, the first stationary seal ring 5 is disposed below the first rotary seal ring 4 in a state in which it cannot be rotated with respect to the seal housing 3 and is supported so as to be movable in the direction of the axis P of the rotary shaft 1. Has been. A disk 19 is externally mounted on the working ring 16 via a snap ring 18.

  The slide ring 6 is composed of a lower ring 6A that is fitted into the intermediate flange 3C so as to be movable up and down, and an upper ring 6B that is fitted onto the upper end boss 6a of the lower ring 6A. An installation hole 6b for dropping and arranging the sealing coil spring 7 is formed. A coil spring 7 for sealing is provided between the slide ring 6 and the stationary seal ring 5 and more specifically, the upper ring 6B and the collar 12 so as to urge the stationary seal ring 5 upward and press it against the rotary seal ring 4. It is interposed between the upper and lower sides.

  The upper ring 6B is formed with a stepped hole 21 for embedding and mounting an interlocking bolt 20 in an inverted direction that is screwed to the collar 12 so as to be relatively movable up and down. The stepped hole 21 includes a small hole portion 21a that allows the bolt body 20a to slide and a large hole portion 21b that loosely fits the bolt head 20b. With this configuration, the interlocking bolt 20, that is, the stationary sealing ring 5 is configured to be movable in the vertical direction (axial center P direction) with respect to the slide ring 6 by a distance e. Further, the sealing coil spring 7 and the interlocking bolt 20 are arranged at a plurality of locations around the axis P, and the installation holes 6b and the stepped holes 21 are also formed at the corresponding plurality of locations.

  The lower ring 6A, which is the lower part of the slide ring 6, has an annular shape that is wide on the outer diameter side following the lower end of the upper end boss portion 6a and that extends downward from the outer peripheral end of the large diameter flange portion 6f. It is formed in a shape having a piston portion 6p, and is sealed using upper and lower O-rings 22 and 23 with respect to the intermediate flange 3C. An annular cylinder comprising inner and outer sliding cylindrical wall portions 24 and 25 fitted to the inner and outer circumferences of the piston portion 6p and an annular bottom wall portion 26 positioned below the piston portion 6p in the seal housing 3 A portion 42 is formed. And by the cylinder part 42, piston part 6p, and the air supply / discharge path 28 formed in the seal housing 3 in order to supply and discharge air to the ring-shaped cylinder chamber cs surrounded by the cylinder part 42 and the piston part 6p. An air cylinder 9 is configured.

  An inner flange 3E having an inner sliding cylindrical wall portion 24 and an annular bottom wall portion 26 is equipped with an O-ring 27 for the piston portion 6p, and a neck portion O-ring 22 inserted and disposed in the intermediate flange 3C. Each of the large-diameter O-ring 23 placed in the piston portion 6p and the inner O-ring 27 placed in the inner sliding cylindrical wall portion 24 is made of PTFE (fluororesin) that can reduce sliding resistance. It is set as the structure which touches a sliding part via slipper ring 22a, 23a, 27a which consists of etc. The intermediate flange 3C is provided with a detaching coil spring 8 that acts on the upper surface of the large-diameter flange portion 6f, and has a function of downwardly biasing the slide ring 6 so as to separate the stationary seal ring 5 from the rotary seal ring 4. Is demonstrated.

  The air cylinder 9 forcibly raises the slide ring 6 against the urging force of the detaching coil spring 8 so as to obtain a sealed state in which the stationary sealing ring 5 is pressed against the rotary sealing ring 4 by the sealing coil spring 7. That is, when the air is supplied from the air supply / discharge passage 28, the piston portion 6p is lifted so that the cylinder chamber cs expands. Therefore, the slide ring 6 reaches a position where the large-diameter flange portion 6f contacts the contact surface 29 of the intermediate flange 3C. , And the stationary seal ring 5 is pressed and urged against the rotary seal ring 5 so as to form the first seal portion S1 (the state shown in FIGS. 1 and 3). It becomes possible.

  As shown in FIGS. 1 and 3, a plurality of auxiliary coil springs 13 acting to push the disk 19 downward are inserted and arranged in the upper end flange 3 </ b> B. This urges the stationary seal ring 5 downward together with the collar 12, and urges the stationary seal ring 5 downward while maintaining a predetermined sealing pressure by pressing the stationary seal ring 5 against the rotary seal ring 4. Means. That is, a cylindrical collar 12 supported on the slide ring 6 so as to be vertically movable between the seal coil spring 7 and the stationary seal ring 5 by an amount e smaller than the vertical movement amount d of the slide ring 6 relative to the seal housing 3. And a downward urging force by the auxiliary coil spring 13 is input to the collar 12 via the disk 19. The function of the auxiliary coil spring 13 is for ensuring the downward movement of the stationary seal ring 5 that lowers its own weight when the seal is open, which will be described later, and is not necessarily required.

  The liquid sealing mechanism 10 circulates while supplying the cooling liquid to the sealing space 30 surrounded by the first seal part S1 and the rotary shaft 1 by pressing the stationary seal ring 5 against the rotary seal ring 4 while being filled. The second seal portion S2 of the second mechanical seal MS2 is also cooled. That is, after the coolant supplied from the inlet passage 31 of the mounting flange 3A cools the first seal portion S1 of the first mechanical seal MS1, and then cools the second seal portion S2 of the second mechanical seal MS2, It is discharged out of the machine through an outlet passage 32 formed in the lower end flange 3D.

  The coolant flow path will be described in detail. The coolant entering from the inlet passage 31 enters the inside of the collar 12 through the peripheral portion of the upper ring 6B and is integrally formed on the upper portion of the upper ring 6B. Part (an example of "cylindrical damming part") 11 and the stationary sealing ring 5 move so as to compete to reach the sealing space 30 and the sealing part S is cooled from the inside. Cooled by. Furthermore, when the coolant that moves up reaches the top of the ring cylinder part 11, it now descends through the annular part between the ring cylinder part 11 and the first sleeve 14, and passes through the inner part of the inner flange 3E. The lower seal space 33 is reached and the second seal portion S2 is cooled from the outside. And the cooling liquid which descend | falls still reaches the exit path 32, and so on.

  The ring cylinder portion 11 protrudes upward from the slide ring 6 so as to promote the circulating action of the coolant by the liquid sealing mechanism 10 in the slide ring 6 in the first seal portion S1, and the rotary shaft 1 (first sleeve 14). It is loosely fitted between the stationary sealing ring 5 surrounding this, and the upper end 11a is disposed so as to reach the first seal portion S1. In the first embodiment, the upper end 11a of the damming portion is set to a position slightly higher than the first seal portion S1 in the sealing action state, more specifically to a position slightly higher than the contact surfaces 4a and 5a. Since the coolant supplied from the supply path 31 flows while filling the inside of the seal housing 3, the coolant exists in the seal space 30 even without the ring cylinder portion 11, but this portion is a flow pool and It is easily predicted that it will become stagnant. Therefore, in the present invention in which the ring cylinder portion 11 projecting upward is provided, the coolant circulates vigorously through the sealing space portion 30, and the first seal portion S1 positioned at the topmost portion as the mechanism is also provided. It is possible to cool and lubricate efficiently.

  The air cylinder 9 is used to move the slide ring 6 upward. When the coolant supplied from the inlet passage 31 fills the seal housing 3, the air cylinder 9 is moved by the fluid pressure (cooling fluid sealing pressure). The slide ring 6 can be maintained in the sealing position without being used. That is, the return path r of the coolant flowing down beyond the ring cylinder portion 11 is configured to include a space formed below the large-diameter flange portion 6 f in the seal housing 3, that is, a lower space portion 34. Therefore, the lower space portion 34 formed on the inner side of the inner flange 3E functions as a cylinder chamber that pushes the large-diameter flange portion 6f upward by the pressure of the coolant present in the inner space 3E. . Therefore, even if there is no air pressure acting on the piston portion 6p, the slide ring 6 can be maintained at the sealing action position where the slide ring 6 is raised.

  The second mechanical seal MS2 includes a second rotary seal ring 36 supported by the upper end pocket 35a of the second sleeve 35 that is fitted over the rotary shaft 1 and the first sleeve 14, and a second rotary seal ring 36 disposed below the second rotary seal ring 36. 2 stationary sealing ring 37, movable cylinder base 38 that receives and statically supports second stationary sealing ring 37, and biasing coil spring 39. The lower part of the movable barrel base 38 is fitted into the inward flange portion 3d at the lower end of the lower end flange 3D so as to be vertically slidable. The plurality of bolts 40 planted in the inward flange portion 3d allows the movable barrel base 38 to be The seal housing 3 is supported by the seal housing 3 so that it cannot rotate around the axis P and can reciprocate within a predetermined range in the direction of the axis P.

  Further, the second stationary seal ring 37 is pressed and urged in the upward direction by the urging forces of the plurality of urging coil springs 39 placed in the movable barrel base 38 and placed on the inward flange portion 3d. As a result, the second stationary seal ring 37 and the second rotary seal ring 36 are pressed against each other to form a second seal portion S2. Reference numeral 41 denotes a pin implanted in the second sleeve 35, which makes the relative rotation between the second rotary sealing ring 36 and the second sleeve 35 impossible.

  Next, the operation of the first mechanical seal MS1 will be described. When air is supplied from the air supply / exhaust passage 28, or when the coolant is supplied from the inlet passage 31 and the pressure of the coolant rises inside the seal housing 3, as shown in FIGS. The slide ring 6 is raised to the sealing action position, and the first mechanical seal MS1 is in a sealing action state in which the first stationary sealing ring 5 is pressed against the first rotary sealing ring 4, and the second mechanical seal MS1 is in a second mechanical state. The seal MS2 is also in a sealing action state in which the second seal portion S2 functions. With this tandem mechanical seal device (sealing pressurization type double seal) A, the stirring tank 2 can be well sealed around the rotary shaft 1.

  In this sealing action state, the height of the seal housing 3 is the structure in which the coolant is injected from the inlet passage 31 located in the middle of the upper and lower positions, but the first position located at the top of the mechanism due to the presence of the ring cylinder portion 11. The liquid sealing mechanism 10 is configured so that the one seal portion S1 can be sufficiently cooled and the slide ring 6 can be maintained at the raised sealing action position using the liquid pressure of the coolant.

  Then, when the air supply is stopped or the coolant supply is stopped, as shown in FIG. 2, the slide ring 6 and the large-diameter flange portion 6f abut against the upper surface of the inner flange 3E by the urging force of the coil spring 8 for separation. The first stationary sealing ring 5 is lowered and maintained at the open position determined in contact with it, and a gap of the vertical interval w is generated between the contact surfaces 4a and 5a, and the first seal portion S1 functions. It is switched to the seal open state that disappears. The opening amount w of the first seal portion S1 at this time is a value obtained by subtracting the vertical movement amount e of the collar 12 with respect to the slide ring 6 from the vertical movement amount d of the slide ring 6 with respect to the seal housing 3, that is, w = de. become. As a result, while the slide ring 6 is moved up and down with a sufficient stroke (movement amount d) so that the position can be clearly switched, the opening amount (opening amount e) of the first seal portion S1 is a little suitable for cleaning. The dimensions can be set. Also, the lower biasing force of the auxiliary coil spring 13 exerts a function of reliably pressing down the first stationary seal ring 5 that is placed on the collar 12 and not connected, and that will be lowered by its own weight.

  By making the seal open, each contact surface 4a, 5a of the first seal portion S1 can be exposed and cleaned clearly. For example, a steam condition of 121 ° C. or higher, which is a sterilization condition based on SIP ( By passing steam) for 20 minutes, it is possible to sterilize the mechanical seal portion without difficulty. Therefore, it is possible to sterilize the seal portion and its contact surface (sliding surface), which has been difficult until now, thereby increasing the reliability of the cleanliness of the device (stirring tank). Further, by forming the large-diameter flange portion 6f having a large diameter on the slide ring 6, the slide ring 6 is resisted against the urging force of the detaching coil spring 8 by the liquid pressure caused by the cooling liquid filled in the lower space portion 34. There is also an advantage that the sealing action state can be maintained by the operation of the liquid sealing mechanism 10.

  As an example of cleaning of the vertical shaft mechanical seal device A, after the operation of the stirrer whose rotation shaft 1 has stopped rotating, the coolant is stretched in the seal housing 3 or the coolant is removed and air is supplied from the air supply port 28. While being pressurized, the operation proceeds to the CIP (stationary cleaning) mode (CIP process) in the stirring tank 2. Thereafter, the supply of the coolant or / and air is stopped, the first seal portion S1 is opened, the seal is opened, and the mode shifts to the SIP (in-place sterilization) mode (SIP process). The above-mentioned steam (pure steam) is supplied into the agitation tank 2, and the steam passes through the contact surfaces 4a and 5a for sterilization and passes through the seal housing 3, that is, through the passage of the coolant, and then the outlet path 32. (Or from the inlet 31).

  As described above, the auxiliary coil spring 13 is for surely moving the first stationary seal ring 5 to the collar 12 so as to follow and move downward. However, the auxiliary coil spring 13 holds the first stationary seal ring 5 when the mechanical seal device is transported. It also has a stabilizing function.

[Another Example]
As shown in FIG. 4, the vertical shaft mechanical seal device A may include a first mechanical seal MS1 having a structure in which the three slipper rings 22a, 23a, and 27a are omitted.

Sectional drawing which shows the structure of the mechanical seal apparatus for vertical shafts by Example 1. Sectional drawing which shows the state which the seal part of the 1st mechanical seal opened in FIG. 1 is an enlarged cross-sectional view of the first mechanical seal portion in FIG. Sectional drawing which shows the mechanical seal apparatus for vertical shafts by another Example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating shaft 3 Seal housing 4 Rotating seal ring 5 Static seal ring 6 Slide ring 6f Large diameter flange part 6p Piston part 7 Sealing coil spring 8 Separation coil spring 9 Air cylinder 10 Liquid seal mechanism 11 Damping part 11a Upper end of damming part 12 Collar 13 Auxiliary coil spring 24 Inner sliding cylinder part 25 Outer sliding cylinder part 26 Annular bottom wall part 28 Air supply / discharge path 30 Sealing space part 34 Space formed below large diameter flange part (lower space part)
42 Cylinder part MS1 1st mechanical seal MS2 2nd mechanical seal P Vertical axis S1 Seal part cs Cylinder chamber d Vertical movement of slide ring e Vertical movement of color r Coolant return path

Claims (4)

A rotary seal ring that rotates integrally with a rotary shaft having a vertical axis;
A stationary seal ring disposed under the rotary seal ring in a state in which it is non-rotatable with respect to the seal housing and supported so as to be movable in the axial direction of the rotary shaft;
A slide member that surrounds the rotating shaft and is supported by the seal housing so as to be capable of reciprocating in a predetermined range in the vertical direction;
A coil spring for sealing interposed between upper and lower sides of the slide ring and the stationary sealing ring to raise and urge the stationary sealing ring against the rotary sealing ring;
A detaching coil spring that urges the slide ring downward to separate the stationary seal ring from the rotary seal ring;
An air cylinder that forcibly raises the slide ring against the urging force of the detaching coil spring to obtain a sealed state in which the stationary sealing ring is pressed against the rotary sealing ring by the sealing coil spring;
A liquid sealing mechanism that circulates while filling and supplying a cooling liquid to a seal space surrounded by the seal portion and the rotary shaft by pressing the stationary seal ring against the rotary seal ring. First mechanical seal,
And a second mechanical seal disposed below the first mechanical seal,
The lower part of the slide ring is formed into a shape having a large-diameter flange portion extending outward in the diameter and an annular piston portion extending downward from the outer peripheral end of the large-diameter flange portion,
In the seal housing, an annular cylinder portion is formed which includes inner and outer sliding cylindrical wall portions fitted to the inner and outer circumferences of the piston portion, and an annular bottom wall portion positioned below the piston portion,
The air cylinder includes the cylinder portion, the piston portion, and an air supply / discharge passage formed in the seal housing for supplying and discharging air to and from a ring-shaped cylinder chamber surrounded by the cylinder portion and the piston portion. Configured,
In order to promote the circulating action of the cooling liquid by the liquid sealing mechanism in the slide ring at the seal portion, the upper part protrudes upward from the slide ring and is loosely fitted between the rotary shaft and the stationary sealing ring surrounding it. Equipped with a cylindrical weir,
The vertical shaft mechanical seal device is configured such that a return path of the coolant flowing down beyond the damming portion includes a space formed below the large-diameter flange portion in the seal housing.
  2. The vertical shaft mechanical according to claim 1, further comprising an auxiliary coil spring for biasing the stationary sealing ring downward while allowing a predetermined sealing pressure to be maintained by pressing the stationary sealing ring against the rotating sealing ring. Sealing device.   A cylindrical collar supported by the slide ring is interposed between the coil spring for sealing and the stationary seal ring so that the slide ring can move up and down by an amount smaller than the amount of vertical movement of the slide ring relative to the seal housing. The vertical shaft mechanical seal device according to claim 2, wherein a downward biasing force by the auxiliary coil spring is input to the collar. The vertical shaft mechanical seal device according to any one of claims 1 to 3, wherein the damming portion provided in the first mechanical seal is disposed such that an upper end thereof reaches the seal portion .

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