WO2013054610A1

WO2013054610A1 - Divided mechanical seal device

Info

Publication number: WO2013054610A1
Application number: PCT/JP2012/072411
Authority: WO
Inventors: 嘉博末藤
Original assignee: イーグル工業株式会社
Priority date: 2011-10-11
Filing date: 2012-09-04
Publication date: 2013-04-18
Also published as: JP5873502B2; JPWO2013054610A1

Abstract

A divided mechanical seal device, wherein: a seal cover (12) can be divided at a division surface (12c) substantially parallel to the shaft core of a rotating shaft (6); a string-shaped primary seal member (15) that prevents leakage of fluid from the division surface (12c) is attached to the division surface (12c) of the seal cover (12), such that at least part (15b) of the primary seal member (15) is exposed to the inner circumferential surface of the seal cover (12); a secondary seal member (35) extending in the circumferential direction is attached to a stationary-side seal ring (30); and the secondary seal member (35) is in contact, so as to be movable along the shaft direction of the rotating shaft (6), with the primary seal member (15) exposed to the inner circumferential surface of the seal cover (12).　

Description

Split type mechanical seal device

The present invention relates to a split-type mechanical seal device.

A mechanical seal device is known as a seal device that seals a gap between a rotating shaft and a casing in a rotating device. In order to attach a mechanical seal device that is not a split type to the rotating device, it is necessary to attach it from the shaft end of the rotating shaft. When other equipment is attached to the shaft end of the rotating shaft, it is necessary to attach the mechanical seal device after removing the equipment.

The split type mechanical seal device does not need to be attached from the end of the shaft because the seal ring is divided, and can be attached from the periphery of the rotating shaft. Easy maintenance.

As a split type mechanical seal device, for example, a device shown in Patent Document 1 shown below is known. In the split-type mechanical seal device, the seal ring can be split and the seal cover can also be split. In order to prevent leakage of the sealing fluid from the split surface of the seal cover, a string-like gasket is attached to the split surface of the seal cover as a primary seal member.

Further, in order to seal the gap between the seal cover and the stationary seal ring, an O-ring groove is formed at a corresponding portion of the seal cover to which the stationary seal ring is attached. A ring is attached so that the O-ring slides on the stationary seal ring. At the bottom of the O-ring groove, the O-ring and the gasket are in pressure contact to prevent leakage of the sealing fluid.

However, in the conventional split-type mechanical seal device, the O-ring attached to the O-ring groove of the seal cover slides on the stationary side sealing ring, and sealing fluid is sealed at that portion. Generally, the stationary-side sealing ring is made of a hard material such as metal, and the O-ring is made of rubber or synthetic resin. Therefore, the O-ring may be damaged as the O-ring slides on the stationary-side sealing ring. .

Also, the O-ring may be deformed by the pressure from the sealing fluid or the force acting during sliding, and the O-ring may enter the split surface of the stationary-side sealing ring, which may damage the O-ring.

Also, since the O-ring moves inside the O-ring groove due to the sliding movement of the sealing ring in the axial direction, especially when the sealing fluid is slurry, the slurry enters the O-ring groove and is fixed. The sealing performance of the is reduced.

Special Table 2003-53347

The present invention has been made in view of such a situation, and an object thereof is to provide a split-type mechanical seal device that is easy to maintain and that suppresses damage to a secondary seal member such as an O-ring and has excellent sealing characteristics. It is to be.

In order to achieve the above object, a split-type mechanical seal device according to the present invention includes:
A rotating side sealing ring attached to the rotating shaft and rotating together with the rotating shaft;
A stationary seal ring attached to the seal cover and sliding in contact with the rotary seal ring in the axial direction;
A split-type mechanical seal device that seals a sealed fluid between the rotary shaft and a seal cover that covers the rotary shaft,
The seal cover or the shaft collar member fixed to the rotating shaft can be divided by a dividing surface so that it can be attached from the periphery of the rotating shaft,
The split surface of the seal cover or the split surface of the shaft collar member has a string-like primary seal member for preventing fluid leakage from the split surface, and at least a part of the primary seal member of the seal cover. It is mounted so as to be exposed to the sealed fluid side,
Either one of the rotating side sealing ring and the stationary side sealing ring includes a secondary seal member extending in the circumferential direction and a bullet that presses the one sealing ring toward the other sealing ring. The firing means is attached,
The secondary seal member is in contact with a portion exposed to the sealed fluid side of the primary seal member.

In the split-type mechanical seal device according to the present invention, the secondary seal member that is attached to one seal ring that moves in the axial direction and slides with a member to which the seal ring is attached includes a rotary side seal ring and a stationary side seal ring. It is attached to either one and is in contact with the primary seal member exposed to the sealed fluid side of the seal cover or the shaft collar member. For this reason, the secondary seal member slides and moves on the primary seal member. For this reason, damage to the secondary seal member due to the secondary seal member sliding with the split surface of the seal cover or the shaft collar member can be suppressed.

In addition, since the contact between the secondary seal member and the primary seal member is performed only on the divided surface of the seal cover or the shaft collar member and not the entire circumference, the frictional force of the secondary seal member with respect to the primary seal member is small, and the secondary seal member The seal member can move smoothly in the axial direction with respect to the primary seal member.

Preferably, the elastic means presses the one sealing ring toward the other sealing ring via a secondary seal member.

By pressing the rotating side sealing ring or stationary side sealing ring through the secondary seal by the elastic means, the elastic side moves in the axial direction together with the rotating side sealing ring or stationary side sealing ring on which the secondary seal member is mounted. For this reason, the secondary seal member does not move in the axial direction relative to any seal ring on which the secondary seal member is mounted, and the structure in which the secondary seal member slides and moves on the primary seal member can be easily achieved. Can be realized.

In addition, since the secondary seal member does not move relative to the seal ring, the secondary seal member is prevented from entering and biting into the split surface of the seal ring, and this also suppresses damage to the secondary seal member. can do. Since damage to the secondary seal member can be suppressed, it is possible to prevent deterioration of the seal characteristics due to the secondary seal member and the primary seal member, and to improve the seal characteristics.

Furthermore, since the sealing ring is pressed through the secondary seal at the contact portion between the secondary sealing member and the primary sealing member, the secondary seal and the sealing ring can be used even when the sealing fluid is slurry or the like. Therefore, there is no possibility that the slurry enters the gap between the secondary seal and the sealing ring and adheres to it, and the axial movement of the secondary seal is prevented from being inhibited, and the deterioration of the sealing characteristics is small.

Preferably, an adapter is attached to the tip of the elastic means, and the secondary seal member is pressed in the axial direction via the adapter. By pressing the secondary seal in the axial direction via the adapter, the secondary seal member can be held between the secondary seal member and the seal ring so as not to move relative to the seal ring.

Preferably, the secondary seal member is mounted on a secondary seal mounting surface provided on the outer periphery of the stationary side sealing ring so as not to move relative to the stationary side sealing ring in the axial direction, The stationary side sealing ring is pressed in the axial direction toward the rotation side sealing ring. By pressing the secondary seal member toward the secondary seal mounting surface by means of elastic means such as a spring, the force is transmitted to the stationary seal ring, and the stationary seal ring is pressed toward the rotary seal ring. The sealing characteristics between these sealing rings are improved.

Also, by pressing the secondary seal member toward the secondary seal mounting surface by the elastic means, it becomes easy to mount the secondary seal member on the stationary seal ring so as not to move in the axial direction.

FIG. 1 is a schematic partial longitudinal sectional view of a split mechanical seal device according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of an essential part taken along line II-II shown in FIG. FIG. 3 is an exploded perspective view showing the interrelationship among the stationary side sealing ring, the primary seal, the secondary seal member, and the adapter shown in FIGS. 1 and 2. FIG. 4 is a schematic partial longitudinal sectional view of a split-type mechanical seal device according to another embodiment of the present invention.

First Embodiment Hereinafter, the present invention will be described based on the embodiments shown in the drawings.
As shown in FIG. 1, the split mechanical seal device 2 according to an embodiment of the present invention leaks from an internal gap 8 between a casing 4 and a rotary shaft 6 of a pump or other fluid machine to an external gap 10. An apparatus for sealing a fluid to be tried. This device 2 includes a seal cover 12 and a rotating side sealing ring 20 and a stationary side sealing ring 30 disposed therein as main components.

As shown in FIGS. 1 and 2, the seal cover 12 is composed of

cover halves

12a and 12b that can be divided into two by a dividing surface 12c substantially parallel to the axis of the rotary shaft 6. The

cover halves

12a and 12b are detachably abutted at the dividing surface 12c and are detachably connected by bolts 14. Note that “substantially parallel to the axis of the rotating shaft 6” means that it may be inclined with respect to the axis of the rotating shaft within a range that can be attached from the periphery of the rotating shaft (the same applies hereinafter). Is).

A gasket groove 13 is formed in the split surface 12c of the seal cover 12 along the axial direction with respect to each of the

cover halves

12a and 12b, and a string shape as a string-shaped primary seal member is formed therein. A gasket 15 is attached. In this embodiment, the cross-section of the string-like gasket 15 is preferably rectangular, and protrudes from the gasket groove 13 in a state where the split surface 12c is not joined, and is crushed in a state where the split surface is joined. The seal function is demonstrated. In addition, the cross-sectional shape of the string-like gasket 15 may be other than a rectangle, for example, a circle or other shapes.

The one joining end surface 12 d in the axial direction of the seal cover 12 is detachably attached to the end surface of the casing 4 by a bolt 16. An O-ring groove 17 formed along the circumferential direction is formed in a ring shape on the joining end surface 12d of the seal cover 12, and an O-ring 18 having a circular cross section is mounted therein. .

The O-ring 18 is cut at, for example, one place in the circumferential direction, and the O-ring 18 can be mounted in the O-ring groove 17 from the outer periphery of the rotating shaft 6. The cut surface of the O-ring 18 is formed obliquely with respect to the radius in the same manner as the cut surface 35c of the O-ring 35 shown in FIG. 3 described later, and the adhesiveness is improved by joining the cut surfaces to each other. ing.

As shown in FIG. 1, the O-ring 18 is crushed between the end face of the casing 4 and the joint end face of the seal cover 12, and attempts to leak radially outward from the internal gap 8 therebetween. Prevents leakage of sealing fluid. In addition, at the bottom of the O-ring groove 17, the O-ring groove 17 and the gasket groove 13 intersect at two circumferential positions, that is, the position of the split surface 12 c of the seal cover 12, and one first end of the gasket 15. The portion 15a and the O-ring 18 are in pressure contact with each other. Therefore, leakage of the sealing fluid that attempts to leak from the internal gap 8 to the outside through the dividing surface 12c is prevented at the position of the first end 15a of the gasket 15.

Rotation side sealing ring 20 and stationary side sealing ring 30 are arranged in the gap between seal cover 12 and rotating shaft 6 to constitute a mechanical seal. The rotation-side sealing ring 20 has a rotation sliding surface 21 that slides with respect to the stationary sliding surface 31 of the stationary-side sealing ring 30, and the axis of the rotation shaft 6 is the same as the stationary-side sealing ring 30 described later. And a structure that can be divided into two along a dividing plane substantially parallel to.

The rotation-side sealing ring 20 is detachably fixed to the rotation shaft 6 by the shaft collar 22 and the holder 40, and rotates together with the rotation shaft 6. As with the seal cover 12 shown in FIG. 2, the shaft collar 22 can be divided into two parts by a dividing surface substantially parallel to the axis of the rotating shaft 6, and the divided half can be separated by a bolt 24. It is connected. The inner peripheral portion of the shaft collar 22 is in close contact with the outer periphery of the rotating shaft 6 by tightening the bolt 24, and the shaft collar 22 is fixed to the rotating shaft 6 and rotates together with the rotating shaft 6.

The shaft collar 22 and the holder 40 are detachably connected by a ring 26 and a bolt 27, and the holder 40 is positioned on the outer periphery of the rotation side sealing ring 20, and between the holder 40 and the rotation side sealing ring 20, An O-ring 42 is attached to ensure a seal between them. The O-ring 42 is made of the same synthetic resin or rubber as the O-ring 18, and has a cut surface at one place in the circumferential direction, like the O-ring 18.

A concave groove 29 is formed on the inner peripheral side of the rotary seal ring 20 near the shaft collar located next to the holder 40 and the rotary seal ring 20 in the axial direction, and an O-ring 28 is attached thereto. The gap between the rotation side sealing ring 20 and the rotation shaft 6 is sealed. The O-ring 28 is also made of the same synthetic resin or rubber as the O-ring 18, and has a cut surface at one place in the circumferential direction like the O-ring 18.

As with the seal cover 12 shown in FIG. 2, the holder 40 can be divided into two parts by a dividing surface substantially parallel to the axis of the rotary shaft 6, and the divided halves can be separated by bolts 44. It is. By tightening the bolts 44 of the holder 40, the adhesion on the split surface of the two-split rotary side sealing ring 20 is also improved. In addition, the split halves of the rotation-side seal ring 20 use bolts for the seal ring 20 itself by tightening the holder 40 in the same manner as the split halves 30a and 30b of the stationary-side seal ring 30 described later. It adheres on the dividing surface without.

As shown in FIG. 1 and FIG. 2, the stationary-side sealing ring 30 can be divided into two

halves

30a and 30b at a dividing surface 30c substantially parallel to the axis of the rotary shaft 6, A holder 50 is disposed on the outer periphery. An O-ring 52 is attached between the holder 50 and the stationary-side sealing ring 30 to ensure a sealing property between them. The holder 50 is non-rotatable with respect to the seal cover 12 by the non-rotating pin 56, but is allowed to move in the axial direction.

By tightening the split halves of the holder 50 with the bolts 54, the adhesion on the split surface of the two-part stationary ring 30 is also improved. As shown in FIG. 3, the split halves 30a and 30b of the stationary-side sealing ring 30 are split without using bolts in the sealing ring 30 itself by tightening the holder 50 with the bolts 54 shown in FIG. The surface 30c is closely attached.

As shown in FIG. 3, an O-ring groove 32 having a semicircular cross section is formed along the circumferential direction on the outer peripheral surface of the stationary seal ring 30 close to the stationary sliding surface 31. An O-ring 52 shown in FIG. 1 is mounted in the O-ring groove 32 and seals between the O-ring groove 32 and the holder 50.

A secondary seal mounting surface 33, an adapter front end mounting surface 34, and an adapter rear end mounting surface 36 are formed in this order on the outer peripheral surface of the stationary seal ring 30 adjacent to the O-ring groove 32 in the axial direction. . An O-ring 35 is mounted on the secondary seal mounting surface 33. The O-ring 35 has a cutting surface 35c that is oblique to the radius at one place in the circumferential direction, and the string-shaped O-ring 35 is connected to the cutting surface 35c to form a ring-shaped O-ring. ing. The cut surface 35c is kept sealed only by joining without using an adhesive, but may be joined using an adhesive.

As shown in FIG. 1, the secondary seal mounting surface 33 has an arc shape (R of about ¼ of a circle) whose cross section matches the outer peripheral shape of the O-ring 35. The outer periphery of the O-ring 35 is the maximum outer diameter of the stationary seal ring 30 with the O-ring 35 mounted on the secondary seal mounting surface 33. It jumps out from the outer peripheral surface. The dimension of the outer periphery of the O-ring 35 protruding radially outward from the outer peripheral surface 38 having the maximum outer diameter of the stationary-side sealing ring 30 is not particularly limited, but with respect to the cross-sectional diameter d1 (see FIG. 3) 1 or less and preferably larger than the gap width c1 between the outer peripheral surface 38 of the stationary seal ring 30 and the inner peripheral surface of the seal cover 12 shown in FIG.

The O-ring 35 contacts the secondary seal mounting surface 33 and also contacts the cylindrical outer peripheral surface which is the adapter tip mounting surface 34. The adapter tip mounting surface 34 is also in contact with the inner peripheral surface of the tip of the adapter 63 so that the tip surface 63 a of the adapter 63 can contact the O-ring 35. As shown in FIG. 1, the tip surface 63 a of the adapter 63 is recessed in conformity with the outer peripheral surface shape of the O-ring 35, and comes into close contact with the O-ring 35.

The rear end portion 63b of the adapter 63 is formed with a large-diameter portion having a larger diameter than the tip portion and a small-diameter portion having a smaller inner diameter than the tip portion, and the inner peripheral surface of the small-diameter portion is the adapter shown in FIG. The rear end mounting surface 36 is mounted. Compared with the outer peripheral surface 38 having the maximum outer diameter of the stationary-side sealing ring 30, the outer diameter is smaller in the order of the adapter front end mounting surface 34 and the adapter rear end mounting surface 36.

The adapter 63 is made of, for example, a synthetic resin harder than the flexible O-ring 35 and the gasket 15, and is made of, for example, a fluororesin. As shown in FIG. 3, the adapter 63 has a cut surface 63c at one place in the circumferential direction, and the adapter 63 is opened at the cut surface 63c so that the stationary side sealing ring extends from the outer peripheral side of the rotating shaft 6 shown in FIG. It can be attached to 30 mounting surfaces 36. After being attached to the mounting surface 36 of the stationary seal ring 30, they are joined to each other at the cut surface 63c due to the elasticity of the adapter 63 itself. Note that the adapter 63 may be of a two-divided type similarly to the stationary side sealing ring 30.

The O-ring 35 and the gasket 15 are made of a material that is more flexible than the adapter 63. For example, the O-ring 35 is made of NBR, FKM, EPDM, FFKM, IIR, NR, etc., and the gasket 15 is made of NBR, It consists of FKM, EPDM, FFKM, IIR, NR, etc. The O-ring 35 and the gasket 15 can be made of different materials, but the O-ring 35 and the gasket 15 are preferably made of the same material.

One end of a plurality of springs 62 arranged in the circumferential direction is in contact with the rear end surface of the adapter 63 so as to press the adapter 63 in the O-ring 35 direction. The other end of the spring 62 is held by a retainer 60 as shown in FIG. Similar to the seal cover 12, the retainer 60 is configured by a half-divided body that can be divided into two parts, and is assembled so as to be divided by bolts 64. The retainer 60 is detachably attached to the outer end surface of the seal cover 12 by a bolt 66.

The spring force by the spring 62 attached to the retainer 60 is transmitted to the adapter 63, presses the O-ring 35, and presses the O-ring 35 against the secondary seal mounting surface 33. The pressing force is transmitted to the stationary side sealing ring 30, and the stationary sliding surface 31 of the stationary side sealing ring 30 is pressed against the rotational sliding surface 21 of the rotating side sealing ring 20.

That is, the stationary side sealing ring 30 is attached to the seal cover 12 together with the holder 50 and the O-ring 35 so as to be movable in the axial direction with respect to the seal cover 12. Moreover, in the present embodiment, the other second end 15b of the string-like gasket 15 provided on the dividing surface 12c of the seal cover 12 is at least within the movement range in the axial direction of the O-ring 35. It is exposed on the peripheral surface and is in pressure contact with a part of the outer peripheral surface of the O-ring 35.

Therefore, the O-ring 35 is slidable along the second end portion 15b of the gasket when moving in the axial direction together with the stationary-side sealing ring 30, and the sealing property between them is maintained. . Further, the outer peripheral portion of the O-ring 35 is in contact with the inner peripheral surface of the seal cover 12 except for the contact portion with the second end portion 15b of the gasket. Accordingly, it is possible to prevent leakage of the sealing fluid that leaks from the gap width c1 between the outer peripheral surface 38 of the stationary seal ring 30 and the inner peripheral surface of the seal cover 12 shown in FIG.

In FIG. 1,

reference numerals

68 and 70 denote a set plate and a set bolt, respectively, for aligning the axis of the stationary seal ring 30 with respect to the axis of the rotary shaft 6. After 2 is mounted around the axis of rotation 6, it is removed.

In this embodiment, the material of the rotation side sealing ring 20 and the stationary side sealing ring 30 is not particularly limited. For example, the rotation sealing ring 20 is composed of SiC, C, SiN, Al ₂ O ₃ , zirconia, or the like, and is stationary. The side sealing ring 20 is made of SiC, C, SiN, Al ₂ O ₃ , zirconia, or the like. These sealing rings 20 and 30 are made of a material harder than the O-ring 35.

In the split mechanical seal device 2 according to this embodiment, the O-ring 35 as a secondary seal member is mounted so as to move simultaneously in the axial direction with respect to the stationary-side seal ring 30, and the inner peripheral surface of the seal cover 12. The second end portion 15b of the gasket 15 exposed to is movably contacted along the axial direction of the rotary shaft 6. For this reason, the O-ring 35 slides and moves on the second end 15 b of the gasket 15 without moving relative to the stationary seal ring 30 in the axial direction. For this reason, damage to the O-ring 35 due to the O-ring 35 sliding on the stationary seal ring 30 can be suppressed.

Further, since the O-ring 35 does not move relative to the stationary seal ring 30, the O-ring 35 is prevented from entering and biting into the split surface 30c of the stationary seal ring 30, and in this respect as well, the O-ring 35 is prevented. Damage can be suppressed. Since damage to the O-ring 35 can be suppressed, deterioration of the sealing characteristics due to the O-ring and the gasket 15 can be prevented, and the sealing characteristics can be improved.

Since the contact between the O-ring 35 and the gasket 15 is performed only on the dividing surface 12c of the seal cover 12 and not the entire circumference, the frictional force of the O-ring 35 against the gasket 15 is small, and the O-ring 35 is Can move smoothly in the axial direction.

Further, since the relative position between the secondary seal and the sealing ring does not change at the contact portion between the O-ring 35 and the gasket 15, even when the sealing fluid is slurry, the slurry is not between the secondary seal and the sealing ring. There is no risk of entering and fixing into the gap, preventing the secondary seal from moving in the axial direction and preventing deterioration of the seal characteristics.

In addition, in the present embodiment, a ring-shaped adapter 63 is attached to the tip of the spring 62, and the O-ring 35 is pressed in the axial direction via the adapter 63. By pressing the O-ring 35 in the axial direction via the adapter 63, the O-ring 35 is held between the O-ring 35 and the stationary-side sealing ring 30 so as not to move relative to the sealing ring 30. Can do.

Second Embodiment A split-type mechanical seal device 102 according to another embodiment of the present invention shown in FIG. 4 is a modification of the embodiment shown in FIGS. An O-ring 235 as a seal member and a spring 62 are attached, and a gasket 215 as a primary seal member is attached to the split surface of the shaft collar 122. Although described in detail below, in FIG. 4, members common to the members shown in the embodiment shown in FIGS. 1 to 3 are given the same reference numerals, and a part of the description is omitted.

This device 102 includes a seal cover 12 and a rotation side sealing ring 120 and a stationary side sealing ring 130 disposed therein as main components. Also in this embodiment, the seal cover 12 is configured by

cover halves

12a and 12b (see FIG. 2) that can be divided into two by a dividing surface 12c substantially parallel to the axis of the rotating shaft 6.

A gasket groove 13 is formed in the split surface 12c of the seal cover 12 along the axial direction with respect to each of the cover halves, and a string-like string-like gasket 115 is mounted therein. The string-like gasket 115 is the same as the string-like gasket shown in FIGS.

At the bottom of the O-ring groove 17, the O-ring groove 17 and the gasket groove 13 intersect at two circumferential positions, that is, at the position of the split surface 12 c of the seal cover 12, and one first end 115 a of the gasket 115. And the O-ring 18 are in pressure contact with each other. Therefore, leakage of the sealing fluid that attempts to leak from the internal gap 8 to the outside through the dividing surface 12c is prevented at the position of the first end 115a of the gasket 115.

Rotation side sealing ring 120 and stationary side sealing ring 130 are arranged in the gap between seal cover 12 and rotating shaft 6 to constitute a mechanical seal. The rotation-side sealing ring 120 has a rotation sliding surface 121 that slides with respect to the stationary sliding surface 131 of the stationary-side sealing ring 130. And a structure that can be divided into two along a parallel dividing plane.

The rotation-side sealing ring 120 is detachably fixed to the rotation shaft 6 by the shaft collar 122 and rotates together with the rotation shaft 6. The shaft collar 122 can be divided into two by a split surface 122c substantially parallel to the axis of the rotary shaft 6, and the split halves are connected to each other by a bolt 124 so as to be separable. The inner peripheral portion of the uniaxial collar 22 is brought into close contact with the outer periphery of the rotating shaft 6 by tightening the bolt 24, and the shaft collar 122 is fixed to the rotating shaft 6 and rotates together with the rotating shaft 6.

The shaft collar 122 is equipped with a ring 126 and an O-ring 128 to seal the gap between the rotation-side sealing ring 120 and the rotation shaft 6. The O-ring 128 is also made of the same synthetic resin or rubber as the O-ring 18 and has a cut surface at one place in the circumferential direction like the O-ring 18 shown in FIG.

As with the stationary side sealing ring 30 shown in FIG. 1, the stationary side sealing ring 130 can be divided into two divided halves on a dividing surface substantially parallel to the axis of the rotary shaft 6, A holder 50 is arranged. An O-ring 52 is attached between the holder 50 and the stationary-side sealing ring 130 to ensure a sealing property between them.

On the outer peripheral surface of the stationary seal ring 130 close to the stationary sliding surface 131, an O-ring groove 32 having a semicircular cross section is formed along the circumferential direction. An O-ring 52 is mounted in the O-ring groove 32 and seals between the holder 50.

On the outer peripheral surface of the stationary seal ring 130, a seal mounting surface 133 and an adapter tip mounting surface 134 are formed in this order next to the O-ring groove 32 in the axial direction. An O-ring 135 is attached to the seal attachment surface 133. The O-ring 135 constitutes a ring-shaped O-ring by connecting the string-like O-ring at the cut surface.

The seal mounting surface 133 has an arc shape (R of about ¼ of a circle) whose cross section matches the outer peripheral shape of the O-ring 135, and has a gap between the seal ring 130 and the O-ring 135. Further, the outer periphery of the O-ring 135 protrudes from the outer peripheral surface of the maximum outer diameter of the stationary seal ring 130 with the O-ring 135 mounted on the seal mounting surface 133. . The dimension in which the outer periphery of the O-ring 135 protrudes outward in the radial direction from the outer peripheral surface 138 having the maximum outer diameter of the stationary seal ring 130 is the same as that of the O-ring 35 and the outer peripheral surface 38 in the embodiment shown in FIGS. Same as relationship.

In the present embodiment, the other second end 115 b of the string-like gasket 115 provided on the split surface 12 c of the seal cover 12 is exposed on the inner peripheral surface of the seal cover 12, and the outer peripheral surface of the O-ring 135. It comes to press-contact with a part of.

The O-ring 135 contacts the seal mounting surface 133 and also contacts the outer peripheral surface of the cylinder that is the adapter tip mounting surface 134. The adapter tip mounting surface 134 is also in contact with the inner peripheral surface of the tip of the adapter 163 so that the tip surface of the adapter 163 can contact the O-ring 135. Like the adapter 63 shown in FIGS. 1 to 3, the tip surface of the adapter 163 is recessed in conformity with the shape of the outer peripheral surface of the O-ring 135 and is in close contact with the O-ring 135.

The rear end of the adapter 163 is held by a retainer 160. Like the seal cover 12, the retainer 160 is configured by a half-divided body that can be divided into two parts, and is assembled so as to be divided by bolts. The retainer 160 is detachably attached to the outer end surface of the seal cover 12 by a bolt 166.

The adapter 163 has the same configuration as the adapter 63 shown in FIGS. The O-ring 135 and the gasket 115 are made of the same material as the O-ring 35 and the gasket 15 shown in FIGS.

An O-ring groove is formed along the circumferential direction on the outer peripheral surface of the rotary seal ring 120 close to the rotary sliding surface 121. An O-ring 42 is mounted in the O-ring groove and seals between the holder 40 and the O-ring groove.

A seal mounting surface 233 and an adapter tip mounting surface 234 are formed in this order on the outer peripheral surface of the rotation-side seal ring 120 adjacent to the O-ring groove in which the O-ring 42 is mounted in the axial direction. An O-ring 235 as a secondary seal member is attached to the seal attachment surface 233. The O-ring 235 constitutes a ring-shaped O-ring by connecting the string-like O-ring at the cut surface.

The seal mounting surface 233 has an arc shape (R of about ¼ of a circle) whose cross section matches the outer peripheral shape of the O-ring 235 and has a gap between the sealing ring 120 and the O-ring 235. In addition, the outer periphery of the O-ring 235 protrudes from the outer peripheral surface having the maximum outer diameter of the rotation-side seal ring 130 with the O-ring 235 mounted on the seal mounting surface 233. . The dimension in which the outer periphery of the O-ring 235 protrudes radially outward from the outer peripheral surface having the maximum outer diameter of the rotary seal ring 120 is the relationship between the O-ring 35 and the outer peripheral surface 38 in the embodiment shown in FIGS. Is the same.

The O-ring 235 contacts the seal mounting surface 233 and also contacts the outer peripheral surface of the cylinder that is the adapter tip mounting surface 234. The adapter tip mounting surface 234 is also in contact with the inner peripheral surface of the tip of the adapter 263 so that the tip surface of the adapter 263 can contact the O-ring 235. The tip surface of the adapter 263 is recessed in conformity with the outer peripheral surface shape of the O-ring 235 so as to be in close contact with the O-ring 235, like the adapter 63 shown in FIGS.

The adapter 263 has the same configuration as the adapter 63 shown in FIGS. The O-ring 235 and the gasket 215 are made of the same material as the O-ring 35 and the gasket 15 shown in FIGS.

One end of a plurality of springs 62 arranged in the circumferential direction is in contact with the rear end surface of the adapter 263 so as to press the adapter 263 in the O-ring 235 direction. The other end of the spring 262 is held by the shaft collar 122.

The spring force by the spring 62 attached to the shaft collar 122 is transmitted to the adapter 263, presses the O-ring 235, and presses the O-ring 235 against the secondary seal mounting surface 233. The pressing force is transmitted to the rotation-side sealing ring 120, and the stationary sliding surface 121 of the rotation-side sealing ring 120 is pressed against the rotation sliding surface 131 of the stationary-side sealing ring 130.

That is, the rotation-side sealing ring 120 is attached to the shaft collar 122 so as to be movable in the axial direction with respect to the shaft collar 122 together with the holder 40 and the O-ring 235. In addition, in the present embodiment, one first end 215a of the string-like gasket 215 provided on the split surface 112c of the shaft collar 122 abuts on the outer peripheral portion of the O-ring 128 on the split surface 112c. Sealing performance is ensured. The other second end 215 b of the gasket 215 is exposed to the inner peripheral surface of the shaft collar 122 at least within the axial movement range of the O-ring 235, and is pressed against a part of the outer peripheral surface of the O-ring 235. It is supposed to be.

Therefore, the O-ring 235 is slidable along the second end 215b of the gasket 215 when moving in the axial direction together with the rotation-side sealing ring 120, and maintains a sealing property between them. Yes. Further, the outer peripheral portion of the O-ring 235 is in contact with the inner peripheral surface of the shaft collar 122 except for the contact portion with the second end portion 215b of the gasket. Therefore, it is possible to prevent leakage of the sealing fluid that leaks to the outside from the gap width between the outer peripheral surface of the rotation-side sealing ring 120 and the inner peripheral surface of the shaft collar 122.

In the split mechanical seal device 2 according to the present embodiment, the O-ring 235 as a secondary seal member is mounted so as to move simultaneously in the axial direction with respect to the rotation-side seal ring 120, and the inner peripheral surface of the shaft collar 122. The second end portion 215b of the gasket 215 exposed to slidably contacts with the second shaft 215b along the axial direction of the rotary shaft 6. For this reason, the O-ring 235 slides and moves to the second end portion 215b of the gasket 215 without moving relative to the rotation-side sealing ring 120 in the axial direction. For this reason, damage to the O-ring 235 due to the O-ring 235 sliding on the rotation-side sealing ring 120 can be suppressed.

Further, since the O-ring 235 does not move relative to the rotation-side sealing ring 120, the O-ring 235 is prevented from entering and biting into the split surface of the rotation-side sealing ring 120. Damage can be suppressed. Since damage to the O-ring 235 can be suppressed, deterioration of the sealing characteristics due to the O-ring 235 and the gasket 215 can be prevented, and the sealing characteristics can be improved.

Since the contact between the O-ring 235 and the gasket 215 is performed only on the dividing surface 212 c of the shaft collar 122 and not the entire circumference, the frictional force of the O-ring 235 with respect to the gasket 215 is small, and the O-ring 235 is against the gasket 215. Can move smoothly in the axial direction.

Further, since the relative position between the secondary seal and the sealing ring does not change at the contact portion between the O-ring 235 and the gasket 215, even when the sealing fluid is a slurry or the like, the slurry does not move between the secondary seal and the sealing ring. There is no risk of entering and fixing into the gap, preventing the secondary seal from moving in the axial direction and preventing deterioration of the seal characteristics.

In addition, in the present embodiment, a ring-shaped adapter 263 is attached to the tip of the spring 62, and the O-ring 235 is pressed in the axial direction via the adapter 263. By pressing the O-ring 235 in the axial direction through the adapter 263, the O-ring 235 is held between the O-ring 235 and the rotation-side sealing ring 120 so as not to move relative to the sealing ring 120. Can do.

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

For example, in the embodiment described above, an O-ring as a secondary seal member is attached to the stationary seal ring 30, but an O-ring as a secondary seal may be attached to the rotary seal ring 20. Is possible.
In the above-described embodiment, the inside type mechanical seal device in which the sealing fluid exists on the outer peripheral side of the sealing rings 20 and 30 has been described. However, the outside type in which the sealing fluid exists on the inner peripheral side of the sealing rings 20 and 30 has been described. The present invention can also be applied to a mechanical seal device.
Further, in the above-described embodiment, the seal cover 12 and the housing 4 are constituted by different members, but the structure of the present invention can be applied to an apparatus in which these are integrated. In that case, the housing 4 also serves as a seal cover.

The split mechanical seal device of the present invention can be widely used as a seal device for sealing a gap between a rotating shaft and a casing in a rotating device such as a pump or a compressor.

2, 102 ... Split mechanical seal device 4 ... Casing 6 ... Rotating shaft 12 ...

Seal cover

15, 215 ... Gasket (primary seal member)
20, 120 ... rotation

side sealing ring

21, 121 ...

rotation sliding surface

22, 122 ...

shaft collar

30, 130 ... stationary

side sealing ring

31, 131 ... stationary sliding

surface

33, 233 ... secondary

seal mounting surface

35, 235 ... O-ring (secondary seal member)
40, 50 ... Holder 60 ... Retainer 62 ... Spring 63 ... Adapter

Claims

A rotating side sealing ring attached to the rotating shaft and rotating together with the rotating shaft;
A stationary seal ring attached to the seal cover and sliding in contact with the rotary seal ring in the axial direction;
A split-type mechanical seal device that seals a sealed fluid between the rotary shaft and a seal cover that covers the rotary shaft,
The seal cover or the shaft collar member fixed to the rotating shaft can be divided by a dividing surface so that it can be attached from the periphery of the rotating shaft,
The split surface of the seal cover or the split surface of the shaft collar member has a string-like primary seal member for preventing fluid leakage from the split surface, and at least a part of the primary seal member of the seal cover. It is mounted so as to be exposed to the sealed fluid side,
Either one of the rotating side sealing ring and the stationary side sealing ring includes a secondary seal member extending in the circumferential direction and a bullet that presses the one sealing ring toward the other sealing ring. The firing means is attached,
The split mechanical seal device, wherein the secondary seal member is in contact with a portion exposed to the sealed fluid side of the primary seal member.
2. The split mechanical seal device according to claim 1, wherein the elastic means presses the one sealing ring toward the other sealing ring via a secondary sealing member.
The split-type mechanical seal device according to claim 2, wherein an adapter is attached to a tip of the elastic means, and the secondary seal member is pressed in the axial direction via the adapter.
The secondary seal member is mounted on the secondary seal mounting surface provided on the outer periphery of the stationary side sealing ring so that it cannot move relative to the stationary side sealing ring in the axial direction.
The split mechanical seal device according to any one of claims 1 to 3, wherein the stationary seal ring is pressed in the axial direction toward the rotary seal ring.