JP6385347B2 - mechanical seal - Google Patents

Description

  The present invention relates to a mechanical seal, and in particular, to a mechanical seal used for a shaft sealing portion.

  A mechanical seal that seals around a rotation axis of a pump or the like is known. In the mechanical seal, sealing is performed by slidingly contacting a rotating ring on the rotating side fixed on the rotating shaft side and a non-rotating ring on the stationary side fixed on the stationary side of the pump body or the like.

  As such a mechanical seal, for example, a mechanical seal having a configuration described in Patent Document 1 is known.

Japanese Patent Laying-Open No. 2005-048818

  In the configuration of Patent Document 1, the set claw engagement body 13 having a function of supporting the movable sealing ring 40 is configured as an annular member. Therefore, the member that connects the movable sealing ring 40 to the seal case 3 is used. A certain set claw engaging body 13 is arranged so as to extend over the entire circumference of the rotating shaft on the air side surface.

On the other hand, the seal case 3 is formed with a notch for a bolt 15 used to attach the seal case 3 (case body 14) to the shaft seal casing 1 so as to extend radially inward. . For this reason, in the configuration in which the set claw engaging body 13 extends over the entire circumference as in Patent Document 1, the notch for the bolt 15 is formed so that the inner end is positioned radially outward from the set claw engaging body 13. Is done.
As a result, the attachment position of the seal case 3 to the pump main body or the like is a position radially outward from the engagement member 13 for the set claw, so that there is a problem that the radial dimension of the mechanical seal becomes large.

  This invention is made | formed in order to solve such a subject, and it aims at providing the mechanical seal which can make a radial dimension compact.

According to the present invention,
A mechanical seal that seals the periphery of the rotating shaft by sliding contact between a rotating ring fixed to the rotating shaft and a stationary ring connected to a main body through which the rotating shaft passes;
A cylindrical stationary side cover coupled to the body;
A cylindrical stationary spring retainer that houses a spring member that is coupled to the radially inner side of the stationary cover and presses and biases the stationary ring toward the rotating ring;
A plurality of retainer pressing members for fixing the stationary spring retainer to the stationary cover,
The plurality of retainer pressing members are arranged at positions separated in the circumferential direction.
A mechanical seal is provided.

  According to such a configuration, the stationary side spring retainer is fixed by the retainer pressing member at a position separated in the circumferential direction, so that a region that can be used for a bolt hole or the like on the surface of the stationary side spring retainer is widened. , Design flexibility is improved.

  Further, since the stationary spring retainer is fixed by the retainer pressing member at a position separated in the circumferential direction, it becomes possible to fix the stationary spring retainers having different shapes by the retainer pressing member having the same shape. As a result, for example, a retainer pressing member having the same shape is fixed to a stationary spring retainer in a so-called double seal type mechanical seal provided with two pairs of sliding surfaces, and a so-called inside shape having a pair of sliding surfaces. Alternatively, it can be used for fixing the stationary side spring retainer in the outside type single seal type mechanical seal. That is, the parts can be shared, and the manufacturing cost can be reduced.

According to another preferred embodiment of the invention,
The retainer pressing member is disposed at least at two positions opposed in the radial direction of the stationary spring retainer.

  According to such a configuration, the stationary spring retainer can be reliably fixed to the stationary cover by the retainer pressing member.

According to another preferred embodiment of the invention,
The retainer pressing member is fitted into a notch that opens in a radial direction formed at a circumferentially spaced position of the stationary spring retainer, and the stationary spring retainer is attached to the stationary cover. Are fixed.

  In such a configuration, a cylindrical stationary spring retainer that houses a spring member that presses and biases the stationary ring toward the rotating ring is fixed to the stationary cover by the retainer pressing member, and this retainer pressing member Is fitted into a notch extending in the radial direction of the stationary spring retainer.

  Therefore, fixing of the stationary spring retainer that accommodates the spring member and prevention of rotation of the stationary spring retainer are achieved by a single member called a retainer pressing member.

According to another preferred embodiment of the invention,
The retainer pressing member is a rectangular plate-shaped member,
The circumferential length of the notch is set to be approximately equal to the length of the plate-like retainer pressing member.

According to another preferred embodiment of the invention,
The length of the notch in the axial direction is set substantially equal to the thickness of the plate-like retainer pressing member.

According to such a configuration,
The axial movement of the stationary spring retainer can be restricted by fitting the retainer pressing member to the notch portion of the stationary spring retainer and fixing the stationary spring retainer to the stationary cover.

According to another preferred embodiment of the invention,
The mechanical seal is a self-air cooled mechanical seal.

  According to the present invention having such a configuration, a mechanical seal capable of reducing the size in the radial direction is provided.

It is sectional drawing of the state in which the mechanical seal of 1st Embodiment of this invention was attached to the rotating shaft. It is a front view of the principal part of a mechanical seal which shows the relation of the stationary side cover of a mechanical seal of a 1st embodiment, a retainer, and a retainer pressing member. It is a disassembled perspective view of the principal part of the mechanical seal of 1st Embodiment. It is sectional drawing of the state in which the mechanical seal of 2nd Embodiment of this invention was attached to the rotating shaft. It is a front view of the principal part of a mechanical seal which shows the relation of the stationary side cover of a mechanical seal of a 2nd embodiment, a retainer, and a retainer pressing member. It is sectional drawing of the state in which the mechanical seal of 3rd Embodiment of this invention was attached to the rotating shaft. It is sectional drawing of the state in which the mechanical seal of 4th Embodiment of this invention was attached to the rotating shaft.

  Hereinafter, a mechanical seal according to a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a state in which a mechanical seal 1 according to a first embodiment of the present invention is attached to a rotating shaft S.

  The mechanical seal 1 of the present embodiment is a seal that seals between a rotating shaft of a rotating device such as a pump having a rotating shaft and a casing wall of the rotating device that extends through the rotating shaft. This is a so-called double seal provided with a surface. In addition, the material of each component of the mechanical seal 1 is the same as or similar to the material of the component of the conventional mechanical seal.

  The mechanical seal 1 of this embodiment includes a substantially cylindrical stationary cover 2 that is connected and fixed to a casing wall (not shown) of a rotary device such as a pump having a rotation shaft S. An annular first stationary ring 6 is connected to the radially inner side of the stationary cover 2 via an O-ring 4 so as to be movable in the axial direction. The first stationary ring 6 is arranged so that the rotation axis S extends through the central space.

  A cylindrical sleeve 8 is fixed to the outer periphery of the rotation shaft S. An annular first rotating ring 12 is connected and fixed to the outer peripheral surface of the sleeve 8 via an O-ring 10. The annular tip surface 12 a of the first rotating ring 12 abuts on the annular tip surface 6 a of the first stationary ring 6, and the first sealing surface of the mechanical seal 1 is between the distal surface 6 a of the first stationary ring 6. (Sliding contact surface) is formed.

  An annular second rotating ring 14 is connected and fixed at a position on the axially outer side (that is, the atmosphere side) of the sleeve 8.

  On the other hand, an annular second stationary ring 16 is arranged at a position on the axially outer side (that is, the atmosphere side) of the first stationary ring 6 on the radially inner side of the stationary cover 2. The second stationary ring 16 is connected to the stationary side cover 2 via an annular spring retainer 18 and is disposed so that the rotation shaft S extends through the central space.

  The annular tip surface 14 a of the second rotating ring 14 abuts on the annular tip surface 16 a of the second stationary ring 16, and the second sealing surface of the mechanical seal 1 is between the tip surface 16 a of the second stationary ring 16. (Sliding contact surface) is formed.

  A pin P extending outward in the axial direction is attached to the spring retainer 18. This pin P is fitted into an axially extending hole formed in the second stationary ring 16 to prevent relative rotation of the second stationary ring 16 with respect to the spring retainer 18.

  As shown in FIG. 1, the spring retainer 18 is formed with a first spring recess 20 that opens inward in the axial direction (in-machine direction). A first coil spring 22 is accommodated in the first spring recess 20, and the first coil spring 22 rotates the first stationary ring 6 through the projection 24 formed at the end of the first stationary ring 6. It is energized in the direction of the ring 12.

  Further, the spring retainer 18 is formed with a second spring recess 26 that opens outward in the axial direction (atmospheric direction). A second coil spring 28 is accommodated in the second spring recess 26, and the second coil spring 28 connects the second stationary ring 16 to the second via a protruding member 30 formed on the distal end side of the second stationary ring 16. It is energized in the direction of the rotating ring 14.

  The spring retainer 18 is fixed to the stationary cover 2 by a plurality of (two) plate-like retainer pressing members 34 that are connected and fixed to the stationary cover 2 by screws 32.

  2 is a front view of the main part of the mechanical seal 1 showing the relationship between the stationary cover 2, the spring retainer 18, and the retainer pressing member 34. FIG. 3 is an exploded perspective view of the main part of the mechanical seal 1. FIG.

  In the mechanical seal 1, two cutout portions 36 that open radially outward are formed at positions spaced apart in the circumferential direction of the outer periphery of the spring retainer 18, specifically, at positions opposed to the diameter direction. ing. The dimensional shape of the notch 36 is such that the tip of the plate-like retainer pressing member 34 is fitted with almost no gap.

  As shown in FIG. 2, four ground bolt notches G are formed in the stationary cover 2 at an angular interval of 90 degrees so as to extend to the radially inward position. The notch 36 is formed at four ground bolt notches G and a position offset in the circumferential direction.

  As shown in FIGS. 1 to 3, each retainer pressing member 34 is connected to the stationary cover 2 by two screws 32 in a state where the tip portion is fitted in the notch 36. It is fixed. As a result, the spring retainer 18 is fixed to the stationary cover 2 in a state where movement in the circumferential direction and the axial direction (both inward and outward in the axial direction) is restricted by the two retainer pressing members 34. Is done.

  As described above, the notch portion 36 is offset in the circumferential direction from the notch G for the ground bolt, so that the retainer pressing member 34 fitted to the notch portion 36 interferes with the notch G for the ground bolt. Without this, the spring retainer 18 can be fixed to the stationary cover 2.

  The mechanical seal 1 of the present embodiment includes a first rotating ring 12 and a second rotating ring 14 that are fixed to the rotating shaft side, a first stationary ring 6 and a second stationary ring 6 that are fixed to the stationary side such as a pump body. The stationary rings 16 are in sliding contact with each other. Therefore, when the rotating shaft is rotating, a sliding torque in the rotating direction of the rotating shaft acts on the first stationary ring 6 and the second stationary ring 16 on the stationary side. This sliding torque is transmitted to the spring retainer 18.

  In the present embodiment, the distal end portion of each retainer pressing member 34 is connected and fixed to the stationary cover 2 by the two screws 32 in a state where the distal end portion is fitted in the notch 36 of the spring retainer 18. Since the spring retainer 18 is fixed to the stationary cover 2 in a state where movement in the circumferential direction and the axial direction is restricted by the retainer pressing member 34, the rotation by the sliding torque causes the retainer pressing member 34 to rotate. And the notch 36 are suppressed.

  Next, the mechanical seal 50 of 2nd Embodiment of this invention is demonstrated. FIG. 4 is a cross-sectional view similar to FIG. 1 showing a state in which the mechanical seal 50 of the second embodiment of the present invention is attached to the rotating shaft S.

  The mechanical seal 50 of the present embodiment is also a seal that seals between a rotating shaft of a rotating device such as a pump having a rotating shaft and a casing wall of the rotating device through which the rotating shaft extends. It differs from the mechanical seal 1 of 1st Embodiment by the point which is a pair of what is called a single seal. The mechanical seal 50 of the second embodiment is a so-called inside type mechanical seal that seals a fluid that leaks from the outer periphery to the inner periphery of the sliding surface.

  The mechanical seal 50 of this embodiment includes a substantially cylindrical stationary cover 52 that is connected and fixed to a casing wall (not shown) of a rotary device such as a pump having a rotation axis S. An annular stationary ring 56 is coupled to the radially inner side of the stationary cover 52 via an O-ring 54 so as to be movable in the axial direction. The stationary ring 56 is disposed so that the rotation axis S extends through the central space.

  A cylindrical sleeve 58 is fixed to the outer periphery of the rotation shaft S. An annular rotating ring 62 is connected and fixed to the outer peripheral surface of the sleeve 58 via an O-ring 60. The front end surface 62 a of the rotating ring 62 is configured to abut on the front end surface 56 a of the stationary ring 56 and to form a seal surface (sliding contact surface) of the mechanical seal 50 between the front end surface 56 a of the stationary ring 56. ing.

  An annular spring retainer 64 is disposed at the radially inner position of the stationary cover 52 and is connected and fixed to the stationary cover 52. The spring retainer 64 is formed with a spring recess 66 that opens in the axial direction toward the stationary ring 56. A coil spring 68 is accommodated in the spring recess 66, and the coil spring 68 urges the stationary ring 56 in the direction of the rotating ring 62 via a protrusion 70 formed at the end of the stationary ring 56.

  Further, similarly to the above embodiment, in the mechanical seal 50 of the present embodiment, the spring retainer 64 is provided by a plurality of (two) plate-like retainer pressing members 74 connected and fixed to the stationary cover 52 by screws 72. The stationary cover 52 is fixed.

  FIG. 5 is a front view of the main part of the mechanical seal 50 showing the relationship among the stationary cover 52, the spring retainer 64, and the retainer pressing member 74.

  As shown in FIG. 5, the two retainer pressing members 74 are held by the screws 72 in a state where the outer edge portion of the spring retainer 64 is sandwiched between the stationary cover 52 and the diametrically opposed positions. The stationary cover 52 is fixed from the outside direction (right direction in FIG. 4). As a result, the spring retainer 64 is fixed to the stationary cover 52 by the retainer pressing member 74.

  The two retainer pressing members 74 are disposed at the stationary cover 52 with four ground bolt notches G formed to extend to the radially inward position at an angular interval of 90 degrees, The position is separated (offset) in the direction. As a result, the retainer pressing member 74 can fix the spring retainer 64 to the stationary cover 52 without interfering with the ground bolt notch G.

  Next, a mechanical seal 80 according to a third embodiment of the present invention will be described. FIG. 6 is a cross-sectional view similar to FIGS. 1 and 4 showing a state in which the mechanical seal 80 according to the third embodiment of the present invention is attached to the rotating shaft S. FIG.

The mechanical seal 80 of this embodiment has a structure similar to the mechanical seal 50 of the second embodiment. The difference from the mechanical seal 50 is that the mechanical seal 50 is a so-called inside type mechanical seal, whereas the mechanical seal 80 seals a fluid that leaks from the inner periphery to the outer periphery of the sliding surface. This is a side-type mechanical seal.
Hereinafter, the mechanical seal 80 of the third embodiment will be described focusing on differences from the mechanical seal 50 of the second embodiment.

  The mechanical seal 80 of the present embodiment includes a substantially cylindrical stationary side cover 82 that is connected and fixed to a casing wall (not shown) of a rotary device such as a pump having a rotation axis S. An annular spring retainer 86 is arranged on the radially inner side of the stationary cover 82 via an O-ring 84. Furthermore, a stationary ring 90 is disposed on the radially inner side of the spring retainer 86 via an O-ring 88. The stationary ring 90 is arranged so that the rotation axis S extends through the central space.

  An annular body 92 is fixed to the outer periphery of the rotating shaft S on the outer side in the axial direction of the stationary ring 90 (outward in the machine direction). An annular rotating ring 94 is connected and fixed to the outside of the annular body 92 in the axial direction (outward in the machine direction).

  The stationary ring 90 is configured to be movable in the axial direction, is formed in the spring retainer 86, and is moved outwardly (to the right in FIG. 6) by a spring 92 housed in a recess opening toward the stationary ring 90. It is pressed.

  As a result, the distal end surface of the stationary ring 90 comes into contact with the distal end surface of the rotating ring 94, and a seal surface (sliding contact surface) of the mechanical seal 80 is formed between the distal end surface of the rotating ring 94.

  Also in the mechanical seal 80 of the present embodiment, the spring retainer 86 is supported by two plate-like retainer pressing members 96 that are connected and fixed to the stationary cover 82 by screws 98, similarly to the mechanical seal 50 of the second embodiment. The stationary cover 82 is fixed.

  The two retainer pressing members 96 are opposed to each other in the diametrical direction, with the outer edge of the spring retainer 86 held between the stationary cover 82 and the screw 98 from the outside direction (right side in FIG. 6). The stationary cover 82 is fixed. As a result, the spring retainer 86 is fixed to the stationary cover 82 by the retainer pressing member 96.

  The positions where the two retainer pressing members 96 are arranged are four ground bolt notches formed in the stationary cover 82 at an angular interval of 90 degrees and positions separated (offset) in the circumferential direction. ing. As a result, the retainer pressing member 96 can fix the spring retainer 86 to the stationary cover 82 without interfering with the ground bolt notch.

  Next, the mechanical seal 100 of 4th Embodiment of this invention is demonstrated. FIG. 7 is a cross-sectional view similar to FIGS. 1, 4, and 6, showing a state where the mechanical seal 100 of the fourth embodiment of the present invention is attached to the rotating shaft S.

The mechanical seal 100 of the present embodiment is self-air cooled, for example, as described in Japanese Patent Application Laid-Open No. 2010-32020, in which air flows into the interior due to rotation of the rotating shaft and the sliding surface is cooled by this air flow. A basic mechanical seal is used.
Hereinafter, a description will be given centering on points unique to the mechanical seal 100 of the present embodiment.

  The mechanical seal 100 includes a rotating ring 102 attached to the rotating shaft S so as to rotate together with the rotating shaft S, and a non-rotating stationary ring attached to a casing (not shown) side of a device such as a pump. 104. A configuration in which the front end surface of the rotating ring 102 and the front end surface of the stationary ring 104 are in sliding contact to form a seal surface, and the space between the inside of the casing (inside space) and the outside of the casing (outside space) is sealed. It has become.

  In the mechanical seal 100 of the present embodiment, the rotary ring 102 is located outside the machine (on the right side in FIG. 7) and exposed to the atmosphere such as the atmosphere outside the machine, and the stationary ring 104 is located inside the machine, It is configured to seal the fluid in the machine on the circumferential side.

  The rotating ring 102 is made of carbon or the like, and is connected to the rotating shaft S via a backup ring 106 made of aluminum or the like. A rotation stop is disposed between the rotating ring 102 and the backup ring 106 to prevent relative rotation between the rotating ring 102 and the backup ring 106.

  On the other hand, the stationary ring 104 is fixed to a casing cover 110 that is a casing side member via an annular spring retainer 108. The distal end surface of the stationary ring 104 is configured to be in sliding contact with the distal end surface of the rotating ring 102 to form a seal surface.

  In the mechanical seal 100 of this embodiment, a cover 112 is disposed at a predetermined interval radially outward of the rotary ring 102 and the backup ring 106, and a gap 114 is provided between the cover 112 and the rotary ring 102 and the backup ring 106. Is formed. The cover 112 is a bottomed cylindrical body having a bottom surface that is open at the center, and is disposed so that the bottom is located away from the backup ring 106 in the axially outward direction.

  A blower mechanism is incorporated in the bottom of the cover 112. When the cover 112 rotates integrally with the rotating ring 102 with the rotation of the rotating shaft S, the cover 112, the rotating ring 102, and the backup ring 106 are circulated by the blower mechanism as shown by the arrow F in FIG. Is further sucked into the gap 114 between them, and further sent to the seal surface between the tip surface of the stationary ring 104 and the tip surface of the rotating ring 102 to cool the seal surface.

  Also in the mechanical seal 100 of this embodiment, like the mechanical seals of the other embodiments described above, the annular spring retainer 108 is supported by two plate-like retainer pressing members 118 that are connected and fixed to the casing cover 110 by screws 116. The casing cover 110 is fixed.

  With the two retainer holding members 118 opposed to each other in the diametrical direction (a position separated in the circumferential direction), the outer edge of the spring retainer 108 is sandwiched between the casing cover 110 and the screw 116. It is fixed to the casing cover 110 from the direction (right side in FIG. 7). As a result, the spring retainer 108 is fixed to the casing cover 110 by the retainer pressing member 118.

  The positions at which the two retainer pressing members 118 are disposed are four ground bolt cutouts formed in the casing cover 110 at an angular interval of 90 degrees and positions offset in the circumferential direction. As a result, the retainer pressing member 118 can fix the spring retainer 108 to the casing cover 110 without interfering with the ground bolt notch.

  The present invention is not limited to the above-described embodiment, and various changes or modifications can be made within the scope of the matters described in the claims.

1: mechanical seal 2: stationary side cover 4: O-ring 6: first stationary ring 6a: tip surface 10 of first stationary ring 6: O-ring 12: first rotating ring 12a: tip surface 14 of first rotating ring 12 : Second rotating ring 16: second stationary ring 18: spring retainer 32: screw 34: retainer pressing member 36: notch

Claims (6)

A mechanical seal that seals the periphery of the rotating shaft by sliding contact between a rotating ring fixed to the rotating shaft and a stationary ring connected to a main body through which the rotating shaft passes;
A cylindrical stationary side cover coupled to the body;
A cylindrical stationary spring retainer that houses a spring member that is coupled to the radially inner side of the stationary cover and presses and biases the stationary ring toward the rotating ring;
A plurality of retainer pressing members for fixing the stationary spring retainer to the stationary cover,
The retainer pressing member is a rectangular plate-shaped member,
The plurality of retainer pressing members are arranged at positions separated in the circumferential direction,
A mechanical seal characterized by that. The retainer pressing member is disposed at least at two positions opposed in the radial direction of the stationary spring retainer.
The mechanical seal according to claim 1. The retainer pressing member is fitted into a notch that opens in a radial direction formed at a circumferentially spaced position of the stationary spring retainer, and the stationary spring retainer is attached to the stationary cover. Fixed
The mechanical seal according to claim 1 or 2. The circumferential length of the notch is set substantially equal to the length of the plate-like retainer pressing member,
The mechanical seal according to claim 3 . The length in the axial direction of the notch is set substantially equal to the thickness of the plate-like retainer pressing member,
The mechanical seal according to claim 3 or 4. The mechanical seal is a self-air cooled mechanical seal;
The mechanical seal according to any one of claims 1 to 5.

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