JP6721448B2 - Mechanical seal device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical seal device that presses a stationary seal ring against a rotary seal ring by a ring-shaped packing to slide the ring, and more particularly to a mechanical seal device that can easily clean a sliding surface.

Patent Document 1 below discloses a mechanical seal device in which a ring-shaped packing is fitted and fixed in an annular groove provided on the outer peripheral surface of a stationary seal ring, and the stationary seal ring is pressed against a rotary seal ring to slide. I am doing it.

However, in the conventional mechanical seal device shown in Patent Document 1, the outer peripheral end of the packing is pressed into contact with the case body in a state of being in pressure contact, and the inner peripheral end of the packing is formed into an annular groove on the outer peripheral surface of the stationary sealing ring. It is fitted and fixed to.

Therefore, the slurry component is deposited or sandwiched between the fitting portion of the packing and the stationary seal ring. In particular, a sanitary device needs to clean the inside of the machine after use so that no residual liquid or residue remains.

JP, 2016-44761, A

The present invention has been made in view of such circumstances, and an object thereof is to provide a mechanical seal device in which the sliding surface can be easily cleaned.

In order to achieve the above object, the mechanical seal device according to the first aspect of the present invention is
A rotary seal ring fixed to the rotary shaft and rotating together with the rotary shaft;
A stationary sealing ring having a stationary sliding surface slidable with respect to the rotating sliding surface of the rotating sealing ring and supported by a housing;
A ring-shaped packing made of an elastic material, which is mounted between the housing and the stationary seal ring,
A mechanical seal device having:
The outer peripheral end of the packing is fixed by the housing,
An inner peripheral end portion of the packing is pressed against a part of an outer peripheral surface of the stationary sealing ring so as to be axially movable.
The outer peripheral surface of the stationary seal ring includes a first stopper surface for restricting axial movement of the inner peripheral end of the packing toward the stationary sliding surface, and an inner peripheral end of the packing. A second stopper surface for restricting axial movement toward the opposite side of the stationary sliding surface is provided.

In the mechanical seal device of the present invention, the inner peripheral end of the packing is pressed against the first stopper surface or the second stopper surface by the elastic force of the packing itself and the fluid pressure acting on the side surface of the packing. Under normal operating conditions, the inner peripheral end of the packing is not affected by the elastic force of the packing itself and the fluid pressure acting on the static sliding surface side of the packing rather than the fluid pressure acting on the static sliding surface side of the packing. When the pressure is set to be large, the stationary seal ring is pressed against the first stopper surface and presses the stationary seal ring toward the sliding surface of the rotary seal ring. Therefore, the stationary seal ring and the rotary seal ring slide on the sliding surface, the leakage of the sealed fluid is suppressed at that portion, and the sealing characteristics are improved.

When the mechanical seal device of the present invention is used for sanitary applications using food-grade slurry or the like, a cleaning liquid is allowed to flow instead of the sealing fluid after use to clean the inside of the device (including the container) to which the mechanical seal device is attached. To do. In such a case, since the pressure of the cleaning liquid introduced into the equipment is high, the inner peripheral edge of the packing has a fluid pressure that acts on the elastic force of the packing itself and on the side opposite to the static sliding surface of the packing. The fluid pressure acting on the side surface of the packing on the stationary sliding surface side is set to be larger, and the outer peripheral surface of the stationary sealing ring is axially moved away from the first stopper surface and comes into pressure contact with the second stopper surface.

That is, in the mechanical seal device of the present invention, the inner peripheral end portion of the packing pushes the second stopper surface based on the cleaning liquid pressure acting on the side surface of the packing on the stationary sliding surface side, and the force causes the stationary sealing ring to rotate and seal. It acts in the direction to separate it from the sliding surface of the ring. Therefore, the sliding surface between the stationary sealing ring and the rotating sealing ring opens, and the residue attached to the sliding surface can be easily washed. Further, since the cleaning liquid also enters the gap between the first stopper surface and the inner peripheral end of the packing, the residue that has entered the gap can be easily washed away. The fluid pressure acting on the inner side surface of the packing is preferably variable. That is, it is preferable that the fluid pressure is high during normal operation and low during washing.

Preferably, an annular groove is formed on the outer peripheral surface of the stationary seal ring,
The inner peripheral end portion of the packing enters the annular groove and is pressed against the bottom wall of the annular groove,
Both inner end walls in the axial direction of the annular groove respectively form the first stopper surface and the second stopper surface.

By forming the annular groove on the outer peripheral surface of the stationary seal ring, the first stopper surface and the second stopper surface can be formed at the same time.

Preferably, an axial gap is formed between at least one of the first stopper surface and the inner peripheral end of the packing, and between the second stopper surface and the inner peripheral end of the packing. There is.

With this configuration, the inner peripheral end of the packing can be moved in the axial direction between the first stopper surface and the second stopper surface.

Preferably, the packing has an inclined structure in which, when the rotary seal ring and the stationary seal ring are in contact with each other, the packing is inclined away from the rotary seal ring from the inner peripheral end toward the outer peripheral end, and the outer peripheral end is The housing is sandwiched and fixed from both sides in the axial direction.

With this configuration, it is difficult for the residue of the sealed fluid to enter the gap between the outer peripheral end of the packing and the housing. Even if the inner peripheral edge of the packing moves in the axial direction, the outer peripheral edge of the packing is clamped and fixed from both sides in the axial direction. A puddle is hard to form. Furthermore, when the stationary seal ring separates from the rotary seal ring, it becomes easier for fluid to enter the region at the boundary between the outer peripheral end of the packing and the housing, and the region is easily cleaned. In addition, since the member that restricts the movement of the packing is not arranged on the surface of the housing facing the inner side surface of the packing, the inner peripheral end of the packing is brought into pressure contact with the second stopper surface to rotate the stationary sealing ring into the rotary sealing ring. Can be easily moved in the direction away from the sliding surface. When the member that restricts the movement of the packing is arranged in the radial direction, there is a risk that the packing may come into contact with the restricting member when moving in the axial direction.

In order to achieve the above object, a mechanical seal device according to a second aspect of the present invention is
A first sealing device arranged on the proximal side with respect to the space in which the fluid to be sealed is arranged, and a second sealing device arranged on the distal side,
An intermediate chamber formed between the first sealing device and the second sealing device,
The first seal device is a mechanical seal device according to the first aspect of the present invention.

In the mechanical seal device according to the second aspect of the present invention, an intermediate chamber is formed between the first seal device and the second seal device, and the first seal device relates to the first aspect of the present invention. It is composed of a mechanical seal device. Therefore, the first sealing device of the mechanical sealing device according to the second aspect of the present invention has the same operational effect as the mechanical sealing device according to the first aspect of the present invention.

Particularly in the mechanical seal device according to the second aspect of the present invention, the fluid pressure of the intermediate chamber acts on the side surface of the packing opposite to the stationary sliding surface, and the pressure of the sealed fluid (cleaning liquid) is It acts on the static sliding surface side of the packing. Therefore, by lowering the fluid pressure in the intermediate chamber, it is easy to move the inner peripheral end of the packing based on the cleaning liquid pressure acting on the outer side surface of the packing when cleaning the inside of the equipment. Therefore, the inner peripheral end portion of the packing pushes the second stopper surface, and the force thereof tends to act in the direction of pulling the stationary seal ring away from the sliding surface of the rotary seal ring.

Further, in the mechanical seal device according to the second aspect of the present invention, by providing the intermediate chamber between the first sealing device and the second sealing device, the cleaning liquid can be discharged through the intermediate chamber when cleaning the inside of the device. It is possible.

FIG. 1 is a schematic sectional view of a mechanical seal device according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a main part of the mechanical seal device shown in FIG. FIG. 3 is an enlarged sectional view of an essential part showing a state in which the pressure of the mechanical seal device shown in FIG. 2 has changed. FIG. 4 is an enlarged sectional view of an essential part showing a state in which the pressure of the mechanical seal device shown in FIG. 3 has further changed.

Hereinafter, the present invention will be described based on the embodiments shown in the drawings.
A mechanical seal device according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a sectional view showing the configuration of the mechanical seal device 10. In FIG. 1, the left side is the in-flight IS side, and the right side is the out-of-flight OS side.

The mechanical seal device 10 is a cartridge-type seal device that is mounted in the shaft hole portion 3a of the housing body 3 through which the rotary shaft (shaft) 2 penetrates from the outside OS side. The housing body 3 is, for example, a part of a container or can for storing, stirring, dispersing or crushing foods, pharmaceuticals, chemicals, powders or the like, or a casing of other equipment (agitator, disperser, crusher). Used as. The mechanical seal device 10 is a mechanical seal device that is compatible with such sanitary applications. On the in-machine IS side of the rotary shaft 2, a stirring blade, a dispersion blade, a crushing blade, etc. (not shown) may be fixed.

The cover plate 6 is attached to the axial end surface 3b of the housing body 3, and the first seal case 11 and the second seal case 12 are attached to the outer side (outside OS side) of the cover plate 6. The cover plate 6, the first seal case 11, and the second seal case 12, which respectively form a part of the housing, are fixed to the end surface 3b by bolts in this order from the end surface 3b of the housing body 3 toward the outside OS side. There is. The cover plate 6, the first seal case 11 and the second seal case 12 form a cartridge type housing 8.

An O-ring groove 5 is formed on a mounting surface 6b of a cover plate 6 which is mounted on the end surface 3b of the housing body 3, and an O-ring 4 is mounted on the O-ring groove 5 so that the end surface 3b and the mounting surface 6b are connected to each other. The space between them is sealed.

In the present embodiment, the O-ring groove 5 is formed as close as possible to the inner peripheral wall surface of the shaft hole portion 3a, and the outer diameter of the inner diameter side wall surface of the O-ring groove 5 is the inner peripheral wall surface of the shaft hole portion 3a. The inner diameter may be the same as or slightly smaller than the inner diameter. However, the condition is that the O-ring 4 is pressed against the end face 3b to maintain the sealing property. With this configuration, in the present embodiment, even if the residue of the sealed fluid remains in the O-ring groove 5, the cleaning liquid described below can enter the O-ring groove 5 for cleaning. In the present embodiment, it is preferable to use the O-ring 4 larger than the size of the O-ring groove 5 than usual. Further, an O-ring 14 is attached between the first seal case 11 and the second seal case 12 to seal the gap between them.

In the present embodiment, the mechanical seal device 10 has a first mechanical seal 30 arranged on the in-machine IS side along the axial direction of the rotary shaft 2 and a second mechanical seal 50 arranged on the outside OS side. .. By disposing the first mechanical seal 30 and the second mechanical seal 50 inside the housing main body 3 and the cartridge type housing 8 along the axial direction of the rotary shaft 2, the cartridge type housing 8 An intermediate chamber 70 is formed inside.

The intermediate chamber 70 is formed between the first mechanical seal 30 and the second mechanical seal 50 inside the cartridge type housing 8 (on the inner peripheral side), and these mechanical seals 30 and 50 function properly. In the state, the space on the OS side outside the machine is sealed, and the space on the IS side inside the machine is also sealed.

The inside of the housing body 3 (the gap between the shaft hole portion 3a and the rotary shaft 2) is filled with the sealed fluid, and the first mechanical seal 30 suppresses the sealed fluid from entering the intermediate chamber 70. doing. The second mechanical seal 50 suppresses the cooling fluid existing inside the intermediate chamber 70 from leaking to the outside OS side.

In the present embodiment, the first seal case 11 is formed with a cooling fluid supply hole 71 that communicates with the intermediate chamber 70, and the cooling fluid is supplied to the inside of the intermediate chamber 70 from there. Further, the second seal case 12 is formed with a cooling fluid discharge hole 72 communicating with the intermediate chamber 70, from which the cooling fluid existing inside the intermediate chamber 70 is discharged from the intermediate chamber. ing.

On the inner peripheral side of the cartridge type housing 8, a sleeve 20 is fixed to the outer periphery of the rotary shaft 2 by a sleeve retainer 22 and is rotatable with the rotary shaft 2 around its axis. The sleeve retainer 22 and the sleeve 20 are fixed to the rotary shaft 2 with, for example, a set screw 24.

A pumping ring 80 is fixed to the outer peripheral surface of the sleeve 20 between the sleeve retainer 22 and the sleeve 20 which are axially arranged on the outer peripheral surface of the rotary shaft 2, and is rotatable with the rotary shaft 2. .. The pumping ring 80 has wings 82. An O-ring 86 is mounted between the inner peripheral surface of the pumping ring 80 and the outer peripheral surface of the sleeve 20 to seal the gap between them.

A plurality of oblique through holes 85, each having a suction port 83 and a discharge port 84, are intermittently formed in the wing portion 82 along the circumferential direction. The suction port 83 of the oblique through hole 85 faces the direction of the first mechanical seal 30 inside the intermediate chamber 70, and the discharge port 84 faces the direction of the second mechanical seal 50. Further, the discharge port 84 is located on the outer side in the radial direction than the suction port 83, and the rotation of the ring 80 causes the fluid taken in from the suction port 83 to be discharged from the discharge port 84, and inside the intermediate chamber 70. Face the second mechanical seal 50.

The fluid supplied from the cooling fluid supply hole 71 is directed to the inside of the intermediate chamber 70 located on the inner peripheral side of the first mechanical seal 30, cools the first mechanical seal 30, and then sucks the pumping ring 80. It is sucked into the mouth 83. The fluid discharged from the discharge port 84 of the pumping ring 80 goes to the outer peripheral portion of the second mechanical seal 50 inside the intermediate chamber 70, cools it, and then is discharged to the outside from the cooling fluid discharge hole 72. To be done.

The first mechanical seal 30 has a first rotary seal ring 31 and a first stationary seal ring 41. Similarly, the second mechanical seal 50 has a second rotary seal ring 51 and a second stationary seal ring 61. The material of these sealing rings 31, 41, 51, 61 is not particularly limited, but silicon carbide, carbon, ceramics, etc. are exemplified.

First, the second mechanical seal 50 will be described. The rotary seal ring 51 is fixed on the outside OS side of the pumping ring 80, and rotates together with the pumping ring 80. A notch is formed at the end of the rotary seal ring 51 on the in-flight IS side, and a knock pin 53 is fitted therein and a rotation stopper is formed on the ring 80 to which the knock pin 53 is fixed. There is. An O-ring 52 is attached between the ring 80 and the rotary seal ring 51 to seal the gap between them.

The stationary seal ring 61 has a stationary slide surface 61a that slides on a rotary slide surface 51a that is the axial outer side end surface of the rotary seal ring 51.

The stationary seal ring 61 is attached to the tip of the inner convex portion 12 a of the second seal case 12 via an O-ring 62. The O-ring 62 is elastically deformed between the tip of the inner convex portion 12a of the second seal case 12 and the outer peripheral surface of the stationary seal ring 61, and seals the gap between them, and the intermediate chamber 70 and the external OS are separated from each other. Cut off the space.

The stationary seal ring 61 is prevented from rotating with respect to the second seal case 12 by a knock pin 63 fixed to the inward convex portion 12 a of the second seal case 12. Furthermore, the elastic force of a plurality of coil-shaped compression springs 64 that are provided along the circumferential direction on the side wall surface of the intermediate chamber of the inner convex portion 12 a of the second seal case 12 acts on the stationary seal ring 61. Therefore, the sliding surface 61a of the stationary seal ring 61 is pressed against the sliding surface 51a of the rotary seal ring 51. The stationary seal ring 61 does not rotate with respect to the seal case 12, but is mounted movably in the axial direction.

Next, the first mechanical seal 30 will be described with reference to FIGS. 2 and 3. As described above, the first mechanical seal 30 has at least the first rotary seal ring 31 and the first rotary seal ring 41. The rotary seal ring 31 is fixed to the outer peripheral end of the flange-shaped convex portion 20a provided at the end on the in-machine IS side of the sleeve 20 via an O-ring 32, and rotates together with the sleeve 20 together with the rotary shaft 2. It is possible.

The O-ring 32 is attached between the rotary seal ring 31 and the sleeve 20 to seal the gap between them and to block communication between the in-flight IS and the intermediate chamber 70 from there. Further, a cutout is provided at the inner peripheral end of the rotary seal ring 31, and a knock pin 33 is fitted in the cutout. The knock pin 33 is fixed to the sleeve 20, prevents the rotary seal ring 31 from rotating with respect to the sleeve 20, and ensures that the rotary seal ring 31 rotates together with the sleeve 20 around the axis. A washer 28 and the like are fixed to the outer peripheral surface of the sleeve 20 to prevent the rotary seal ring 31 from moving axially toward the stationary seal ring 41.

A rotary sliding surface 31 a is formed on an end surface of the rotary seal ring 31 facing the stationary seal ring 41. The stationary sliding surface 41a of the stationary sealing ring 41 slides on the rotary sliding surface 31a. The rotary sliding surface 31a is relatively large in the radial direction, but the radial width d1 of the stationary sliding surface 31a is sufficiently smaller than that of the rotary sliding surface 31a. The stationary seal ring 41 has a tapered shape in which the width in the radial direction gradually narrows toward the stationary sliding surface 41a.

With this configuration, at the time of cleaning, which will be described later, it is easy to apply fluid pressure in the direction in which the stationary seal ring 41 is separated from the rotary seal ring 31, and the outer surface of the stationary seal ring 41 near the sliding surface 41a is cleaned with the cleaning liquid. Easy to wash. In addition, the residue of the sealed fluid attached to the rotary sliding surface 31a of the rotary seal ring 31 can easily flow.

A notch-shaped recess 44 is provided on the inner peripheral surface of the stationary seal ring 41, and a knock pin 45 is fitted therein. The knock pin 45 is fixed to the stepped concave surface 11c of the first seal case 11 and projects axially toward the concave portion 44 from there. By fitting the knock pin 45 into the recess 44, the stationary seal ring 41 is prevented from rotating with respect to the first seal case 11. However, the recess 44 has a sufficient length in the axial direction, and the tip of the knock pin 45 does not contact the inner wall of the recess 44. The stationary seal ring 41 is movable in the axial direction unless the end surface 41 b on the side opposite to the sliding surface abuts on the stepped concave surface 11 c of the first seal case 11.

In the present embodiment, the knock pin 33 provided on the rotary seal ring 31 and the knock pin 45 provided on the stationary seal ring 41 are both inside the intermediate chamber 70, and in the normal operation, the in-flight IS side. It does not come into contact with the fluid to be sealed. Therefore, it is possible to reduce the risk that the residue of the sealed fluid adheres to the periphery of these knock pins 33 and 45.

An annular groove 42 is formed on the outer peripheral surface of the stationary seal ring 41. The inner peripheral end portion 40b of the ring-shaped packing 40 is inserted into the annular groove 42 and is pressed against the bottom wall of the annular groove 42. The inner peripheral end portion 40b of the packing 40 is pressed against the bottom wall of the annular groove 42, which is a part of the outer peripheral surface of the stationary seal ring 41, so as to be movable in the axial direction. Both inner end walls of the annular groove 42 in the axial direction form a first stopper surface 42a and a second stopper surface 42b, respectively.

In the present embodiment, the ring-shaped packing 40 has an outer peripheral end portion 40a formed with an axial convex portion 40a1 protruding in the axial direction. The outer peripheral end 40a of the packing 40 formed with the axial convex portion 40a1 includes an inner convex portion 6a protruding further inward in the radial direction from the inner peripheral end of the cover plate 6, and a packing pressing surface of the first seal case 11. It is fixed by being sandwiched between it and 11b from both sides in the axial direction.

On the outer side of the packing pressing surface 11b in the radial direction, the seal case 11 is formed with an axial convex portion 11a that projects in the axial direction with respect to the packing pressing surface 11b. The axial protruding length of the axial convex portion 11a is smaller than the distance between the inward convex portion 6a and the packing pressing surface 11b, and the outer peripheral end 40a of the packing 40 has the inner convex portion 6a and the packing pressing surface. It is compressed from both sides in the axial direction and sandwiched between it and 11b.

The packing 40 includes an outer side surface (side surface facing the stationary sliding surface 41a) 40c facing the space on the IS side in the machine, and an inner side surface facing the space of the intermediate chamber 70 (side opposite to the outer side surface 40c). Side surface) 40d. The outer side surface 40c is inclined from the outer peripheral end portion 40a toward the inner peripheral end portion 40b so as to approach the stationary sliding surface 41a of the stationary sealing ring 41 in a tapered or stepwise manner. The inner side surface 40d is formed such that the distance w1 from the packing pressing surface 11b gradually increases from the outer peripheral end 40a toward the inner peripheral end 40b, or the predetermined distance w1 is maintained. There is.

Since the packing 40 comes into contact with the fluid to be sealed, it is preferably sanitary and is made of, for example, a rubber material such as perfluoroelastomer, EPDM, polyester elastomer or a synthetic resin. Further, a reinforcing material may be embedded inside the packing 40. Examples of the reinforcing material include a metal spring, a metal plate, and a resin plate.

The packing 40 configured as described above seals the gap between the housing 8 and the stationary seal ring 41, and the elastic force of the packing 40 itself acts on the stationary seal ring 41, so that the static seal ring 41 is sealed. It has a function of pressing the stationary sliding surface 41 a against the rotating sliding surface 31 a of the rotary sealing ring 31. When the sealed fluid is stored on the in-flight IS side, the fluid having a predetermined pressure is introduced into the intermediate chamber 70, and the pressure in the intermediate chamber 70 is higher than the pressure of the sealed fluid, the inner side surface 40d of the packing 40 is The static pressure of the packing 40 itself is added to the acting fluid pressure, and the stationary seal ring 41 is pressed toward the rotary seal ring 31.

In this state, as shown in FIG. 2, the outer side surface 40c located on the inner peripheral end 40b side of the packing 40 is pressed against the first stopper surface 42a of the annular groove 42. Therefore, an axial gap w3 is formed between the inner side surface 40d located at the inner peripheral end 40b and the second stopper surface 42b. The axial gap w3 may be a gap that allows fluid pressure to act inside the gap.

In the present embodiment, the gap w2 between the end surface 41b on the side opposite to the sliding surface of the stationary seal ring 41 and the stepped concave surface 11c is sufficiently larger than the axial gap w3, and the distance from the packing pressing surface 11b to the inner side surface 40d. It is smaller than the maximum value of w1. The stepped concave surface 11c may not be formed as long as the axial protrusion width of the axial convex portion 40a1 of the packing 40 can be made sufficiently large. That is, the packing pressing surface 11b may continue to the inner peripheral end of the seal case 11. In that case, the gap w2 is the width of the gap between the end surface 41b on the side opposite to the sliding surface of the stationary seal ring 41 and the packing pressing surface 11b.

In the mechanical seal device 10 of the present embodiment, in a normal operating state, as shown in FIG. 2, the inner peripheral end portion 40b of the packing 40 has a fluid force acting on the elastic force of the packing 40 itself and the inner side surface 40d of the packing 40. The pressure causes the first stopper surface 42a to come into pressure contact with the stationary sealing ring 41 to press it toward the sliding surface 31a of the rotary sealing ring 31. Therefore, the stationary seal ring 41 and the rotary seal ring 31 slide on the sliding surfaces 41a and 31a, and the leakage of the sealed fluid is suppressed at that portion, and the sealing characteristics are improved.

For example, when the mechanical seal device 10 is used for a sanitary application using a slurry for food or the like, a cleaning liquid is caused to flow after use to clean the inside IS of the device (including the container) to which the mechanical seal device 10 is attached. In such a case, the pressure fluid is not introduced into the intermediate chamber 70, and the pressure of the cleaning liquid introduced into the device internal IS is high, so that the pressure of the cleaning liquid acting on the outer side surface 40c of the packing 40 causes the packing 40 to move. As shown in FIG. 3, the inner peripheral end 40b axially moves the outer peripheral surface of the stationary seal ring 41 away from the first stopper surface 42a and comes into pressure contact with the second stopper surface 42b.

That is, the cleaning liquid pressure acting on the outer side surface 40c of the packing 40 becomes larger than the force obtained by adding the elastic force of the packing 40 itself to the fluid pressure acting on the inner side surface 40d of the packing 40, and the inner peripheral end portion 40b of the packing 40. Pushes the second stopper surface 42b. As shown in FIG. 4, the force acts on the stationary seal ring 41 in the direction of separating it from the sliding surface 31 a of the rotary seal ring 31. Therefore, the sliding surfaces 41a, 31a between the stationary sealing ring 41 and the rotating sealing ring 31 are opened, and the residue attached to the sliding surfaces 41a, 31a can be easily washed.

Further, since the cleaning liquid also enters the gap w4 between the first stopper surface 42a and the inner peripheral end portion 40b of the packing 40, the residue that has entered the gap w4 can be easily washed away. The width of the gap w4 shown in FIG. 3 is about the same as the width of the gap w3 shown in FIG. The gap w4 is a gap formed by the inner peripheral end portion 40b of the packing 40 moving on the bottom surface of the annular groove 42. Further, in the present embodiment, the fluid pressure acting on the inner side surface 40d of the packing 40 is caused by the fluid pressure introduced into the intermediate chamber 70, and is set to be high during normal operation and to be as low as atmospheric pressure during cleaning.

Further, the outer peripheral end 40a of the packing 40 is arranged on the opposite side of the inner peripheral end 40b from the rotary seal ring 31 side when the rotary seal ring 31 and the stationary seal ring 41 are in contact with each other, and the outer peripheral end 40a of the housing 8 Since the parts are fixed by being sandwiched from both sides in the axial direction, the packing 40 is deformed so as to cover the inner peripheral end part of the inward convex part 6a, and the residue of the sealed fluid is removed from the outer peripheral end part 40a of the packing 40. Difficult to enter the gap with the housing 8. Further, even if the inner peripheral end portion 40b of the packing 40 moves in the axial direction, since the outer peripheral end portion 40a of the packing 40 is clamped and fixed from both sides in the axial direction, the fixation does not weaken, The packing 40 covering the inner peripheral end of the inner convex portion 6a moves so as to be peeled from the inner peripheral end of the inner convex portion 6a, and a gap between the packing 40 and the inner peripheral end of the inner convex portion 6a. Is large, the residue is easily washed away.

Furthermore, since the outer peripheral end 40a of the packing 40 is sandwiched and fixed from both sides in the axial direction, the outer peripheral end 40a and the inner peripheral end 40b of the packing 40 are opposed to each other in opposite directions. An outer side surface 40c and an inner side surface 40d on which the fluid pressure acts are formed, and these can have substantially the same length in the radial direction. Therefore, the inner peripheral end portion 40b of the packing 40 can be easily moved toward the second stopper surface 42b by applying the pressure of the cleaning liquid to the outer side surface 40c without applying the pressure to the inner side surface 40d.

Further, since the packing 40 is sandwiched from both sides in the axial direction, no member for restricting the movement of the packing 40 is arranged on the packing pressing surface 11b of the housing 8 facing the inner side surface 40d of the packing 40. The inner peripheral end portion 40b of 40 can be brought into pressure contact with the second stopper surface 42b to easily move the stationary seal ring 41 in the direction away from the sliding surface 31a of the rotary seal ring 31.

Further, by forming the annular groove 42 on the outer peripheral surface of the stationary seal ring 41, the first stopper surface 42a and the second stopper surface 42b can be formed at the same time. It is preferable that the axial groove width of the annular groove 42 is slightly larger than the axial width of the inner peripheral end portion 40b of the packing 40 when the inner peripheral end portion 40b of the packing 40 is inserted into the annular groove 42. This is to allow the inner peripheral end portion 40b of the packing 40 to move in the axial direction inside the annular groove 42.

The outer diameter of the bottom wall of the annular groove 42 is preferably smaller than the inner diameter of the stationary sliding surface 41a. With such a configuration, the radial lengths of the outer side surface 40c and the inner side surface 40d can be increased. As a result, the elastic deformation of the inner peripheral end portion 40b of the packing 40 in the axial direction can be increased, and the area of the fluid pressure applied to the outer side surface 40c and the inner side surface 40d of the packing 40 can be increased.

Further, in the present embodiment, the pumping ring 80 having a pumping action is fixed to the rotary shaft 2 so that the fluid supplied to the intermediate chamber 70 flows in the intermediate chamber 70. By disposing the pumping ring 80 in the intermediate chamber 70, a flow of the cooling fluid can be formed in the intermediate chamber 70, and the cooling action of the first mechanical seal 30 and the second mechanical seal 50 is improved.

Further, in the present embodiment, the structure of the double mechanical seal device including the first mechanical seal 30 and the second mechanical seal 50 is adopted, and the sealing characteristics are further improved. Further, since the second rotary seal ring 51 is arranged closer to the intermediate chamber 70 than the second stationary seal ring 61 is, the structure of the mechanical seal device 10 can be simplified.

Further, in the present embodiment, the second rotary seal ring 51 is fixed to the pumping ring 80 and is configured to be rotatable together with the pumping ring 80, so that the configuration of the mechanical seal device 10 can be simplified. ..

Further, in the present embodiment, the radially inner side of the first mechanical seal 30 communicates with the intermediate chamber 70, and the radially outer side of the second mechanical seal 50 communicates with the intermediate chamber 70. With this configuration, the radially inner side of the first mechanical seal 30 to the radially outer side of the second mechanical seal 50 are communicated with each other by the intermediate chamber 70, and a cooling liquid or the like is circulated between them to cool them. Will be easier.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the present invention.

For example, the O-ring 4 exposed to the sealed fluid existing in the in-flight IS is preferably composed of sanitary-compatible perfluoroelastomer, EPDM, or the like. The cleaning liquid is not particularly limited, but may be clean water or water mixed with a cleaning agent.

Furthermore, the first stopper surface and the second stopper surface may be formed by other means instead of being formed on the groove inner end surface of the annular groove 42 of the stationary seal ring 41. For example, a pair of stopper members may be provided separately on the outer peripheral surface of the stationary seal ring 41 at predetermined axial intervals, and the first stopper surface and the second stopper surface may be formed on each stopper member.

Further, the second sealing device is not limited to the second mechanical seal 50, and may be another sealing device. Further, the mechanical seal device of the present invention does not necessarily require the second mechanical seal, and may be configured by only the first mechanical seal.

2...Rotary shaft
3... Housing body 3a... Shaft hole portion 3b... End surface 4... O-ring 5... O-ring groove 6... Cover plate (part of housing)
6a... Inner convex portion 8... Cartridge type housing (part of housing)
10...Mechanical seal device 11...First seal case (part of housing)
11a... Axial convex portion 11b... Packing pressing surface 11c... Stepped concave surface 12... Second seal case (part of housing)
14... O-ring 18... Bolt 20... Sleeve 22... Sleeve retainer 24... Knock pin 26... O-ring 30... First mechanical seal (first sealing device)
31... Rotating sealing ring 31a... Rotating sliding surface 32... O-ring 33... Knock pin 40... Packing 40a... Outer peripheral end 40a1... Axial convex portion 40b... Inner peripheral end 40c... Outer side 40d... Inner side 41... Static sealing Ring 41a... Stationary sliding surface 42... Annular groove 42a... First stopper surface 42b... Second stopper surface 44... Recess 45... Knock pin 50... Second mechanical seal (second sealing device)
51... Rotating sealing ring 51a... Rotating sliding surface 52... O ring 53... Knock pin 61... Stationary sealing ring 61a... Stationary sliding surface 62... O ring 63... Knock pin 64... Coil spring 70... Intermediate chamber 71... Cooling fluid supply Hole 72... Cooling fluid discharge hole 80... Pumping ring 82... Wing portion 83... Suction port 84... Exhaust port 85... Oblique through hole 86... O-ring IS... Machine inside OS... Machine outside

Claims (5)

A rotary seal ring fixed to the rotary shaft and rotating together with the rotary shaft;
A stationary sealing ring having a stationary sliding surface slidable with respect to the rotating sliding surface of the rotating sealing ring and supported by a housing;
A ring-shaped packing made of an elastic material, which is mounted between the housing and the stationary seal ring,
A mechanical seal device having:
The outer peripheral end of the packing is fixed by the housing,
An inner peripheral end portion of the packing is pressed against a part of an outer peripheral surface of the stationary sealing ring so as to be axially movable.
The outer peripheral surface of the stationary seal ring includes a first stopper surface for restricting axial movement of the inner peripheral end of the packing toward the stationary sliding surface, and an inner peripheral end of the packing. comprising a second stopper surface which restricts movement in the axial direction toward the opposite side of the stationary sliding surface tare is,
A mechanical seal device that will be fixed by being sandwiched from both sides in the axial direction by the outer peripheral edge portion of the packing is the housing. An annular groove is formed on the outer peripheral surface of the stationary seal ring,
The inner peripheral end portion of the packing enters the annular groove and is pressed against the bottom wall of the annular groove,
The mechanical seal device according to claim 1, wherein both inner end walls in the axial direction of the annular groove respectively constitute the first stopper surface and the second stopper surface. An axial gap is formed between at least one of the first stopper surface and the inner peripheral end of the packing and between the second stopper surface and the inner peripheral end of the packing. Item 3. The mechanical seal device according to Item 1 or 2. 4. The packing according to claim 1, wherein when the rotary seal ring and the stationary seal ring are in contact with each other, the packing has an inclined structure that separates from the rotary seal ring from an inner peripheral end portion toward an outer peripheral end portion. A mechanical seal device comprising the described mechanical seal device. A first sealing device arranged on the proximal side with respect to the space in which the fluid to be sealed is arranged, a second sealing device arranged on the distal side,
A mechanical seal device having an intermediate chamber formed between the first seal device and the second seal device,
The first sealing device is
A mechanical seal device comprising the mechanical seal device according to claim 1.