JP7080556B2 - mechanical seal - Google Patents

Description

The present invention relates to a mechanical seal that seals a shaft seal formed between a housing and a rotating shaft.

The conventional mechanical seal is attached to a shaft sealing portion formed between the housing and the shaft in a machine in which the shaft is inserted into the housing. The shaft is provided with a rotary-side sealing element having a rotary-sealing ring so as to rotate, and the housing is provided with a fixed-side sealing element having a fixed-sealing ring, and the rotary-sealing ring and the fixed-sealing ring are provided. The shaft sealing portion is sealed by sliding and.

Such a mechanical seal is provided with an urging member that urges the fixed seal ring toward the rotary seal ring side in order to maintain an appropriate sliding state between the rotary seal ring and the fixed seal ring. The fixed seal ring and the rotary seal ring are held in the proper positions in the axial direction, and the mechanical seal is placed between the fixed seal ring and the rotary seal ring while maintaining the proper urging force by the urging means. A so-called cartridge type mechanical seal provided with a set plate for temporarily fixing the fixed side sealing element and the rotating side sealing element is used for installation in (see, for example, Patent Document 1).

JP-A-2007-138965 (Page 7, Fig. 1)

However, in the case of a mechanical seal as in Patent Document 1, when the mechanical seal is installed in the shaft sealing portion, the rotating side sealing element is fixed to the housing and the rotating side sealing element is fixed to the shaft, and then the set plate is used. By removing the mechanical seal, the mechanical seal could be used. In this way, if the shaft rotates with the set plate forgotten to be removed, there is a risk that the mechanical seal will break down.

The present invention has been made focusing on such a problem, and an object of the present invention is to provide a mechanical seal whose installation work is easy.

In order to solve the above problems, the mechanical seal of the present invention is used.
A fixed-side sealing element having a fixed sealing ring, a rotating-side sealing element having a rotating sealing ring, an urging member that urges one of the fixed sealing ring and the rotating sealing ring toward the other, and the fixing. A cartridge-type mechanical seal provided with a set plate for temporarily fixing the side sealing element and the rotating side sealing element, and mounted on the shaft sealing portion.
The set plate is attached to one of the fixed side sealing element and the rotating side sealing element after the mechanical seal is installed in the shaft sealing portion, and the fixed side sealing element and the rotating side are attached to the set plate. The frictional force generated between the other sealing element and the set plate when the other sealing element and the set plate of the sealing elements are relatively rotationally slid becomes zero or reduced. It is characterized by being configured.
According to this feature, after the mechanical seal is installed in the shaft sealing portion, when the other sealing element and the set plate slide with the rotation of the rotating side sealing element, the space between the other sealing element and the set plate is reached. Since the generated frictional force becomes 0 or is reduced, the rotation of the rotating side sealing element is less likely to be affected, and the work of removing the set plate from one of the sealing elements after installing the mechanical seal in the shaft sealing portion can be omitted. ..

Further, the mechanical seal of the present invention is
A fixed-side sealing element having a fixed sealing ring, a rotating-side sealing element having a rotating sealing ring, an urging member that urges one of the fixed sealing ring and the rotating sealing ring toward the other, and the fixing. A cartridge-type mechanical seal provided with a set plate for temporarily fixing the side sealing element and the rotating side sealing element, and mounted on the shaft sealing portion.
The set plate is attached to one of the fixed-side sealing element and the rotating-side sealing element after the mechanical seal is installed in the shaft sealing portion, and at least the surface thereof is made of synthetic resin. It is characterized by being.
According to this feature, since the surface of the set plate is made of synthetic resin, the set plate is scraped due to wear when the other sealing element and the set plate slide with the rotation of the rotating side sealing element. Since the frictional force generated between the other sealing element and the set plate becomes 0 or is reduced, it is less likely to affect the rotation of the rotating side sealing element, and the set plate is placed on one side after the mechanical seal is installed on the shaft seal. The work of removing from the sealing element of the can be omitted.

The surface of the set plate is characterized by having a lower hardness than the other sealing element.
According to this feature, the set plate is easily scraped by sliding with the other sealing element.

The surface of the set plate is characterized by a smaller coefficient of friction than the other sealing element.
According to this feature, the set plate is slippery with respect to the other sealing element, so that it is less likely to affect the rotation of the rotating side sealing element.

The set plate is attached to the rotation-side sealing element, and is characterized by comprising a rotation-regulating means for restricting relative rotation between the set plate and the rotation-side sealing element.
According to this feature, since the set plate and the rotating side sealing element can be integrated by the rotation restricting means, the set plate and the fixed side sealing element can be suitably rotated and slid.

The rotation restricting means is characterized in that it is a groove portion in which the set plate is fitted and installed.
According to this feature, it is possible to prevent the set plate and the rotating side sealing element from rotating relatively with a simple structure.

The rotation-side sealing element is provided with the set plate, and the rotation-side sealing element is characterized by being provided with an inclination restricting member for restricting the tilting of the set plate.
According to this feature, since the tilting restricting member regulates the tilting of the set plate, the set plate can be brought into contact with the fixed side sealing element substantially evenly.

It is a front sectional view which shows the structure of the mechanical seal after being attached to the shaft seal part in Example 1. FIG. It is a front sectional view which shows the structure of the mechanical seal before being attached to the shaft seal part in Example 1. FIG. (A) is an enlarged view of the main part showing the state before the set plate and the case slide immediately after the mechanical seal is attached, and (b) is an enlarged view of the main part showing the state after the set plate and the case slide. Is. (A) is an enlarged view of a main part showing the state before the set plate and the case slide immediately after attaching the mechanical seal in Example 2, and (b) shows the state after the set plate and the case slide. It is an enlarged view of a main part. (A) is an enlarged view of a main part showing the state before the set plate and the case slide immediately after attaching the mechanical seal in Example 3, and (b) shows the state after the set plate and the case slide. It is an enlarged view of a main part. (A) is an enlarged view of a main part showing the state before the set plate and the case slide immediately after attaching the mechanical seal in Example 4, and (b) shows the state after the set plate and the case slide. It is an enlarged view of a main part.

A mode for carrying out the mechanical seal according to the present invention will be described below based on examples.

The mechanical seal according to the first embodiment will be described with reference to FIGS. 1 to 5. Hereinafter, the left side of the paper surface of FIG. 2 will be referred to as the left side of the mechanical seal, and the right side of the paper surface of FIG. 2 will be described as the right side of the mechanical seal.

As shown in FIG. 1, the mechanical seal 1 according to the present embodiment is used in the field of shaft sealing of automobiles, general industrial machines, etc., and is a rotation inserted through a housing 2 and a shaft hole 20 provided in the housing 2. It is attached to seal between the shaft 3 and the shaft (shaft sealing portion). The housing 2 is provided with a stepped shaft hole 20, and a female screw portion 21 is formed on the inner peripheral surface of the small diameter hole on the outside of the machine. The rotary shaft 3 is generally made of metal such as stainless steel, and when the device for sealing the shaft is a pump, an impeller (not shown) is attached to the inside of the machine.

As shown in FIG. 2, the mechanical seal 1 is mainly composed of a case 4, a fixed sealing ring 6, a sleeve 5, a color plate 7, a spring 8, and a rotary sealing ring 9. Before use, the case 4, the fixed sealing ring 6, the sleeve 5, the color plate 7, the spring 8, and the rotary sealing ring 9 are integrated into a cartridge type by the set plate 13. be. The mechanical seal 1 may have a fastening band 14 attached to the sleeve 5 before use.

The case 4 has an annular shape, and a shaft hole 40 through which the sleeve 5 is inserted is provided inside the case 4, and a dust seal 30 is arranged on the inner peripheral surface of the shaft hole 40 to allow foreign matter to enter between the case 4 and the sleeve 5. It regulates what you do. Further, in the case 4, a male screw portion 41 is formed on the outer peripheral surface on the left side. According to this, the case 4 can be fixed to the housing 2 by screwing the male screw portion 41 of the case 4 into the female screw portion 21 of the housing 2 described above (see FIG. 1). Therefore, not only can the case 4 be easily fixed to the housing 2 without using a fixing means such as a bolt separately, but also the mechanical seal 1 can be attached to the housing 2 with a uniform holding force in the circumferential direction. .. Further, after fixing the case 4 to the housing 2 by screwing the male screw portion 41 of the case 4 into the female screw portion 21 of the housing 2, these may be further fixed with bolts or the like. The case 4 is made of a metal such as a stainless steel material or an aluminum alloy.

Further, the case 4 is formed with a flange 42 extending to the outer periphery of the right end edge. According to this, when the case 4 is fixed to the housing 2, the end surface 45 on the housing 2 side of the flange 42 of the case 4 can be brought into contact with the right end surface 22 of the housing 2 (see FIG. 1). Due to this contact, when the case 4 is fixed to the housing 2, the case 4 and the housing 2 are aligned with each other, excessive force is not applied to the female screw portion 21 and the male screw portion 41, and the female screw portion 21 is prevented from exerting an excessive force. It is possible to prevent the male screw portion 41 from being deformed or damaged.

Further, in the case 4, an annular groove 43 is formed on the outer peripheral surface on the left side of the flange 42, and an O-ring 101 is mounted on the annular groove 43. According to this, when the case 4 is fixed to the housing 2, the O-ring 101 can be crimped to the inner peripheral surface of the housing 2 (see FIG. 1). Therefore, the gap between the inner peripheral surface of the housing 2 and the outer peripheral surface of the case 4 can be sealed by the O-ring 101.

Further, since the annular groove 43 is arranged so as to face the inner peripheral surface of the housing 2, the diameter of the flange 42 can be shortened to reduce the size and weight of the case 4. Further, since the case 4 is fixed to the housing 2 by the male screw portion 41 provided on the outer periphery thereof, the diameter dimension of the flange 42 can be shortened.

Further, in the case 4, a fixed sealing ring 6 is attached to the inner circumference on the left side side via an O-ring 102. The fixed sealing ring 6 is provided with a shaft hole 60 through which the sleeve 5 is inserted, and forms an annular shape. Further, the fixed sealing ring 6 is formed with a flange 61 extending to the outer periphery on the left side.

Further, the fixed sealing ring 6 is equipped with an O-ring 102 on the outer periphery of the reduced diameter portion on the right side of the flange 61. According to this, when the fixed sealing ring 6 is fixed to the case 4, the O-ring 102 can be crimped to the inner peripheral surface of the case 4. Therefore, the gap between the inner peripheral surface of the case 4 and the outer peripheral surface of the fixed sealing ring 6 can be sealed by the O-ring 102. The case 4 and the fixed sealing ring 6 constitute a fixed-side sealing element fixed to the housing 2 (see FIG. 1).

The fixed sealing ring 6 is made of SiC by a special conversion method (the carbon surface is partially made into SiC to reinforce the surface strength so that both the abrasion resistance of the SiC and the self-lubricating property of the carbon are combined). It is being manufactured. It may also be made of diamond-coated SiC.

The sleeve 5 is provided with a shaft hole 50 through which the rotating shaft 3 is inserted, and has a tubular shape. Further, an annular groove 57 is formed on the inner peripheral surface on the left side of the shaft hole 50 provided in the sleeve 5, and an O-ring 103 is mounted on the annular groove 57. According to this, when the rotary shaft 3 is inserted into the shaft hole 50 of the sleeve 5, the O-ring 103 can be crimped to the outer peripheral surface of the rotary shaft 3 (see FIG. 1). Therefore, the gap between the inner peripheral surface of the sleeve 5 and the outer peripheral surface of the rotating shaft 3 can be sealed by the O-ring 103.

The sleeve 5 is generally made of metal such as stainless steel, and is fixed to the rotating shaft 3 by a fastening band 14 to rotate together with the rotating shaft 3 (see FIG. 1).

An annular groove 51a is formed on the outer peripheral surface on the left side of the sleeve 5. A color plate 7 is mounted on the annular groove 51a. The color plate 7 is fixed so as not to move relative to the sleeve 5 in the axial direction and the circumferential direction.

Further, as is well known, a spring 8 is arranged in a compressed state between the color plate 7 and the rotary sealing ring 9. The spring 8 is arranged in a type that uses one spring larger than the shaft diameter of the sleeve 5, that is, a one-coil spring type. As the spring 8, in addition to the coil spring, a wave coil spring or the like may be used, or a multi-coil spring may be used.

Further, a guide member 10 is mounted on the right side of the annular groove 51a on the outer peripheral surface of the sleeve 5. The guide member 10 is fixed so as not to rotate in the circumferential direction by being welded to the outer peripheral surface of the sleeve 5. Further, the guide member 10 is composed of a ring-shaped mounting portion 10a and a plurality of L-shaped guide pieces 11 provided in the circumferential direction from the mounting portion 10a. The method of fixing the guide member 10 to the outer peripheral surface of the sleeve 5 is not limited to welding, and may be fixed by using uneven fitting.

Further, the guide piece 11 of the guide member 10 is inserted into a plurality of guide recesses 91 whose free ends are formed on the inner peripheral surface on the left side of the rotary sealing ring 9. The guide recess 91 extends in the axial direction and is formed so as to open to the left side. According to this, the guide piece 11 is inserted into the guide recess 91 to move the rotary sealing ring 9 relative to the sleeve 5 only in the axial direction, and to move the rotary sealing ring 9 to the sleeve 5. Lock so that it does not move relative to the circumferential direction. Therefore, the rotational force of the sleeve 5 is transmitted to the rotary sealing ring 9 by the guide piece 11, and the ring 9 rotates together with the sleeve 5. The sleeve 5 and the rotary sealing ring 9 constitute a rotary side sealing element fixed to the rotary shaft 3 (see FIG. 1).

The rotary sealing ring 9 has an annular shape, and a shaft hole 90 through which the sleeve 5 is inserted is provided inside the rotary sealing ring 9. Further, the rotary sealing ring 9 rotates together with the sleeve 5 in a state where the right side end surface is in contact with the left side end surface of the fixed sealing ring 6. The sliding surface S is formed by abutting the side end surface of the rotary sealing ring 9 and the side end surface of the fixed sealing ring 6. Further, the side end surface of the rotary sealing ring 9 is urged to the right side by an axial urging force applied from the spring 8, and is in close contact with the side end surface of the fixed sealing ring 6. According to this, it is possible to improve the followability of the side end surface of the rotary sealing ring 9 with respect to the side end surface of the fixed sealing ring 6. Therefore, the sealing property of the mechanical seal 1 on the sliding surface S can be improved.

Further, an O-ring 104 is attached to the inner peripheral surface on the left side of the rotary sealing ring 9. According to this, when the rotary sealing ring 9 is inserted through the sleeve 5, the O-ring 104 can be crimped to the outer peripheral surface of the sleeve 5. Therefore, the gap between the inner peripheral surface of the rotary sealing ring 9 and the outer peripheral surface of the sleeve 5 can be sealed by the O-ring 104.

Further, a holding plate 12 is press-fitted onto the rotary sealing ring 9 at a position on the left side of the mounting position of the O-ring 104 on the inner peripheral surface on the left side. The holding plate 12 restricts the movement of the O-ring 104 mounted on the inner peripheral surface of the rotary sealing ring 9 to the left side.

The rotary sealing ring 9 is made of SiC by a special conversion method (the carbon surface is partially made into SiC to reinforce the surface strength so that both the abrasion resistance of the SiC and the self-lubricating property of the carbon are combined). It is being manufactured. It may also be made of diamond-coated SiC.

An annular groove 53a having a substantially rectangular cross section recessed toward the inner diameter is formed on the outer peripheral surface on the right side of the sleeve 5. An annular set plate 13 having a rectangular cross section is fitted in the annular groove 53a. The set plate 13 is made of PTFE (polytetrafluoroethylene) (synthetic resin), and when mounted in the annular groove 53a, it is formed on the right peripheral edge of the shaft hole 40 of the case 4 and is concave in the axial direction. It abuts on the recess 44. According to this, each member inserted through the sleeve 5 can be integrally held between the color plate 7 on the left side and the set plate 13 on the right side while maintaining an appropriate urging force by the spring 8. Therefore, the mechanical seal 1 can be configured as a cartridge type. Further, a C-ring-shaped washer 15 made of a metal such as stainless steel is attached to the outer peripheral surface of the sleeve 5 on the opposite side of the set plate 13 from the case 4.

Further, slits 58, 58, 58, 58 (only one shown) extending in the axial direction are formed at the right end of the sleeve 5 so as to be evenly arranged at 90 degree intervals with respect to the circumferential direction. Further, an annular groove 53b is formed at the end of the sleeve 5 on the right side of the annular groove 53a, and the sleeve 5 is attached and tightened by attaching and tightening the fastening band 14 (tightening member) to the annular groove 53b. It can be fixed to the rotating shaft 3 (see FIG. 1).

The sleeve 5 is formed to have a diameter larger than the inner diameter of the set plate 13, and slits 58, 58, 58, 58 are formed on the right side. When attaching the set plate 13, the central hole of the set plate 13 is inserted into the sleeve 5 with the right side of the sleeve 5 reduced in diameter, and then the reduced diameter state of the sleeve 5 is released to form an annular shape of the sleeve 5. The set plate 13 can be fitted in the groove 53a. When the set plate 13 is fitted in the annular groove 53a, the set plate 13 becomes immovable relative to the sleeve 5 in the axial and circumferential directions.

The materials of the O-rings 101, 102, 103, 104 in this embodiment are fluorine rubber, nitrile rubber, H-NBR, EPDM, perfluoroelastomer, and the like.

Further, the material of the fixed sealing ring 6 and the rotary sealing ring 9 may be a cemented carbide material such as silicon carbide, tungsten carbide, carbon, or other ceramics.

To attach the mechanical seal 1 configured in a cartridge type to the shaft seal portion, insert the color plate 7 side of the mechanical seal 1 from the right side into the shaft hole 20 of the housing 2, and insert the male screw portion 41 of the case 4. If the sleeve 5 is screwed into the female screw portion 21 of the housing 2 and the sleeve 5 is fixed to the rotating shaft 3 by the fastening band 14, the mounting state shown in FIGS. 1 and 3A is obtained.

As shown in FIG. 3A, in the state immediately after the mechanical seal 1 is attached to the housing 2, the end surface 13a on the case 4 side of the set plate 13 is the end surface 46 (annular recess 44) on the right side of the case 4. The end surface 13b on the opposite side of the housing 2 of the set plate 13 is in contact with the washer 15.

As shown in FIG. 3B, when the rotary shaft 3 is rotationally driven, the sleeve 5 rotates the set plate 13 together with the rotary shaft 3, and the end surface 13a of the set plate 13 and the end surface 46 of the case 4 slide. Will come to do. Since the set plate 13 is made of PTFE, which is a synthetic resin, the end surface 13a of the set plate 13 is scraped by friction with the end surface 46 of the case 4, and the end surface 13a of the set plate 13 and the end surface 46 of the case 4 are formed. Separate. As a result, the frictional force generated between the case 4 and the set plate 13 becomes zero. That is, since the work of removing the set plate 13 from the sleeve 5 after installing the mechanical seal 1 in the shaft sealing portion can be omitted, the work of installing the mechanical seal 1 becomes extremely simple. In FIG. 3B, for convenience of explanation, the distance between the end surface 13a of the set plate 13 and the end surface 46 of the case 4 is shown to be larger than the actual size.

Further, the set plate 13 is made of PTFE, which is a synthetic resin, and the case 4 is made of a metal such as a stainless steel material or an aluminum alloy. That is, since the set plate 13 has a lower hardness than the case 4, the set plate 13 is easily scraped by sliding with the case 4, and the frictional force generated between the case 4 and the set plate 13 becomes 0 (set). It is possible to shorten the time required (until the end surface 13a of the plate 13 and the end surface 46 of the case 4 are separated from each other).

Further, since the set plate 13 is made of PTFE, which is a synthetic resin having a small coefficient of friction, the set plate 13 is slippery with respect to the case 4. According to this, it is possible to reduce the frictional force generated until the frictional force generated between the case 4 and the set plate 13 becomes zero. Further, when the frictional force generated between the case 4 and the set plate 13 becomes 0, and then the set plate 13 tilts toward the case 4 or thermally expands, the set plate 13 and the case 4 come into contact with each other. In addition, since the set plate 13 slides on the case 4 to release a large frictional resistance, it does not easily affect the rotation of the rotating shaft 3.

Further, the set plate 13 is attached so as not to be relatively movable in the axial direction and the circumferential direction with respect to the annular groove 53a of the sleeve 5. According to this, since the set plate 13 and the sleeve 5 are integrated, it is possible to prevent the set plate 13 and the sleeve 5 from rotating relatively. Specifically, it is possible to prevent a phenomenon in which only the sleeve 5 rotates while the set plate 13 stops rotating due to friction with the case 4, and the set plate 13 and the case 4 can be suitably rotated and slid. .. That is, the annular groove 53a functions as a rotation regulating means for regulating the relative rotation between the set plate 13 and the sleeve 5.

Further, a C-ring-shaped washer 15 made of a metal such as stainless steel is arranged on the opposite side (end surface 13b side) of the set plate 13 from the case 4. According to this, even if the set plate 13 tries to tilt to the opposite side of the case 4 due to sliding with the case 4, the washer 15 regulates the tilting, so that the end surface 13a of the set plate 13 is the end surface of the case 4. It can be brought into contact with the 46 substantially evenly. That is, the washer 15 functions as a tilting control member that regulates the tilting of the set plate 13.

Further, since the dust seal 30 is arranged between the case 4 and the sleeve 5, it is possible to prevent the wear debris scraped from the set plate 13 from entering the machine, and between the case 4 and the sleeve 5. It is possible to prevent the rotation of the rotating shaft 3 from being hindered by the entry of the wear debris.

In this embodiment, the set plate 13 is made of PTFE, but the set plate 13 is not limited to PTFE and may be freely changed as long as it can be scraped by sliding with the case 4. For example, the set plate may be made of a member having a high coefficient of friction and easily worn so that it can be scraped in a short time.

Further, for example, the end surface 46 of the case 4 may be configured to have a rough surface roughness by blasting or the like so that the set plate 13 can be scraped in a short time.

Further, in this embodiment, the entire set plate 13 is made of synthetic resin (PTFE), but the set plate 13 may be made of synthetic resin as long as the end surface 13a sliding with the case 4 is made of synthetic resin, for example, metal. It may be an insert-molded molded body.

Further, the end surface 13a of the set plate 13 is not limited to surface contact with the end surface 46 of the case 4, and for example, a plurality of protrusions that come into contact with the end surface of the case may be provided on the end surface of the set plate. .. According to this, since the contact area between the end face of the set plate and the end face of the case becomes small (point contact), the frictional force generated between the set plate and the case can be reduced, and the set plate and the case can be contacted with each other. The time required for the frictional force generated between them to be zero or reduced can be shortened.

Further, the set plate 13 may be attached in a state where the relative rotation with respect to the sleeve 5 is restricted by press-fitting and installing the set plate 13 with respect to the annular groove 53a. Further, the rotation regulating means for restricting the relative rotation between the set plate and the rotating side sealing element is not limited to the annular groove 53a, and for example, the set plate 13 and the washer 15 are bonded to each other by an adhesive or uneven fitting. By connecting, the set plate 13 and the sleeve 5 may be prevented from rotating relatively. In this case, the washer 15 can regulate the tilting of the set plate 13 and the relative rotation with the sleeve 5. Further, it is possible to prevent the set plate 13 from tilting toward the case 4.

Further, the set plate 13 has an annular shape, but the present invention is not limited to this, and may be, for example, a plurality of pieces scattered in the circumferential direction of the sleeve 5, or may have a shape such as a C ring. ..

Next, the mechanical seal according to the second embodiment will be described with reference to FIG. It should be noted that the description of the same configuration as that of the above embodiment and the overlapping configuration will be omitted. In FIG. 4B, for convenience of explanation, the distance between the end surface 13a of the set plate 131 and the end surface 31a of the plate 31 is shown to be larger than the actual size.

As shown in FIG. 4A, in the case 4, the annular recess 44'formed on the right peripheral edge of the shaft hole 40 is formed larger in the axial direction than the annular recess 44 of the first embodiment, and is annular. An annular plate 31 having a predetermined thickness is fixedly provided in the recess 44'. The plate 31 is made of PTFE. In other words, the plate 31 is a sliding member made of synthetic resin. Further, the set plate 131 is formed of a metal such as a stainless steel plate.

As shown in FIG. 4B, when the rotary shaft 3 is rotationally driven, the set plate 131 rotates together with the rotary shaft 3, and the end surface 131a of the set plate 131 and the end surface 31a of the plate 31 slide. Become. According to this, the end surface 31a of the plate 31 is scraped by friction with the end surface 13a of the set plate 13, the end surface 13a of the set plate 13 and the end surface 31a of the plate 31 are separated from each other, and between the case 4 and the set plate 13. The generated frictional force can be reduced to zero.

Further, since the plate 31 made of PTFE has a lower hardness than the set plate 131 formed of a metal such as a stainless steel plate, the plate 31 can be easily scraped by sliding with the set plate 13. In this way, the set plate fixed to one sealing element (sleeve 5) is not limited to being scraped, and the member constituting the other sealing element may be scraped.

Next, the mechanical seal according to the third embodiment will be described with reference to FIG. It should be noted that the description of the same configuration as that of the above embodiment and the overlapping configuration will be omitted. In FIG. 5B, for convenience of explanation, the distance between the end faces 13a and 13b of the set plate 13 and the inner peripheral end faces 13c and the annular groove 53a is shown in a larger size than the actual size.

As shown in FIG. 5A, the set plate 13 is fixed to the annular recess 44 of the case 4 by bolts 16, and the inner peripheral side edge of the set plate 13 is inserted into the annular groove 53a. ing.

As shown in FIG. 5B, when the rotary shaft 3 is rotationally driven, the sleeve 5 rotates together with the rotary shaft 3, and the end faces 13a and 13b of the set plate 13, the inner peripheral end faces 13c and the annular groove 53a slide. It will move. According to this, the end faces 13a, 13b and the inner peripheral end face 13c of the set plate 13 are scraped by the friction with the annular groove 53a, and the end faces 13a, 13b and the inner peripheral end face 13c of the set plate 13 and the annular groove 53a are separated from each other. The frictional force generated between the set plate 13 and the annular groove 53a can be reduced to zero. As described above, the set plate 13 is not limited to being fixed to the sleeve 5 (rotating side sealing element), but may be fixed to the case 4 (fixing side sealing element).

Next, the mechanical seal according to the fourth embodiment will be described with reference to FIG. It should be noted that the description of the same configuration as that of the above embodiment and the overlapping configuration will be omitted. In FIG. 6B, for convenience of explanation, the distance between the end faces 132a and 132b of the set plate 132 and the inner peripheral end faces 132c and the recess 32a of the plate 32 is shown in a larger size than the actual size.

As shown in FIG. 6A, the set plate 132 is fixed to the annular recess 44 of the case 4 by bolts 16. The set plate 132 is made of a metal such as a stainless steel plate. Further, the annular groove 53a'is formed larger than the annular groove 53a of Examples 1 to 3, and a recess 32a into which the inner peripheral end edge of the set plate 13 can be inserted is provided in the annular groove 53a'. The annular plate 32 to have is fixed. The plate 32 is made of PTFE. In other words, the plate 32 is a sliding member made of synthetic resin.

As shown in FIG. 6B, when the rotary shaft 3 is rotationally driven, the sleeve 5 rotates together with the rotary shaft 3, and the end faces 132a and 132b of the set plate 132, the inner peripheral end faces 132c, and the recess 32a of the plate 32. Will slide. According to this, the recess 32a of the plate 32 is scraped by friction with the end faces 132a, 132b of the set plate 132 and the inner peripheral end surface 132c, and the end faces 132a, 132b and the inner peripheral end face 132c of the set plate 132 and the recess 32a of the plate 32 are formed. Are separated from each other, and the frictional force generated between the set plate 132 and the plate 32 can be reduced to zero.

Although examples of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these examples, and any changes or additions that do not deviate from the gist of the present invention are included in the present invention. Will be.

For example, in the above embodiment, the set plate attached to one sealing element or a part of the other sealing element (rotating side sealing element or fixed side sealing element) in contact with the set plate is scraped by sliding to form a set plate. An example is shown in which the frictional force generated between the other sealing element is 0, but the present invention is not limited to this, and the set plate is scraped more than before use and between the set plate and the other sealing element than before use. The frictional force generated may be reduced. For example, the set plate may be scraped in a small amount so that the set plate and other sealing elements come into slight contact with each other during use.

Further, in the above embodiment, the embodiment in which the side end surface of the rotary sealing ring 9 is urged against the side end surface of the fixed sealing ring 6 by the spring 8 is brought into close contact with the side end surface of the fixed sealing ring 6, but the fixed sealing ring 6 is brought into close contact with the spring 8. The side end surface may be brought into close contact with the side end surface of the rotary sealing ring 9 by being urged.

1 Mechanical seal 2 Housing 3 Rotating shaft 4 Case (fixed side sealing element)
5 Sleeve (rotating side sealing element)
6 Fixed sealing ring 8 Spring (Ambushing means)
9 Rotating sealed ring 13 Set plate 15 Washer (tilt control member)
30 Dust seal 31, 32 Plate (sliding member)
44,44'annular recess 53a annular groove (rotation regulating means)
131, 132 Set plate S Sliding surface

Claims (12)

A fixed-side sealing element having a fixed sealing ring, a rotating-side sealing element having a rotating sealing ring, an urging member that urges one of the fixed sealing ring and the rotating sealing ring toward the other, and the fixing. A cartridge-type mechanical seal provided with a set plate for temporarily fixing the side sealing element and the rotating side sealing element, and mounted on the shaft sealing portion.
The set plate is attached to one of the fixed side sealing element and the rotating side sealing element after the mechanical seal is installed in the shaft sealing portion, and the fixed side sealing element and the rotating side are attached to the set plate. Of the sealing elements, the other sealing element and the set plate have a frictional force generated between the other sealing element and the set plate when the other sealing element and the set plate are relatively rotationally slid. A mechanical seal characterized in that the frictional force when rotationally sliding is relatively reduced as compared with the frictional force before moving. A fixed-side sealing element having a fixed sealing ring, a rotating-side sealing element having a rotating sealing ring, an urging member that urges one of the fixed sealing ring and the rotating sealing ring toward the other, and the fixing. A cartridge-type mechanical seal provided with a set plate for temporarily fixing the side sealing element and the rotating side sealing element, and mounted on the shaft sealing portion.
The set plate is attached to one of the fixed-side sealing element and the rotating-side sealing element after the mechanical seal is installed in the shaft sealing portion, and the surface of the set plate is fixed . A mechanical seal characterized by having a smaller coefficient of friction than the other sealing element of the side sealing element and the rotating side sealing element . A fixed-side sealing element having a fixed sealing ring, a rotating-side sealing element having a rotating sealing ring, an urging member that urges one of the fixed sealing ring and the rotating sealing ring toward the other, and the fixing. A cartridge-type mechanical seal having a side sealing element and a set plate attached to one of the rotating side sealing elements and attached to the shaft sealing portion.
The set plate is annular and
An annular groove recessed on the inner diameter side is formed on the outer peripheral surface of the rotating side sealing element.
The inner diameter side end of the set plate is arranged in the annular groove.
The surface of the set plate is a mechanical seal having a smaller coefficient of friction than the other sealing element of the fixed-side sealing element and the rotating-side sealing element . The mechanical seal according to any one of claims 1 to 3, wherein the surface of the set plate has a hardness lower than that of the other sealing element. A fixed-side sealing element having a fixed sealing ring, a rotating-side sealing element having a rotating sealing ring, an urging member that urges one of the fixed sealing ring and the rotating sealing ring toward the other, and the fixing. A cartridge-type mechanical seal having a side sealing element and a set plate attached to one of the rotating side sealing elements and attached to the shaft sealing portion.
The set plate is annular and
An annular groove recessed on the inner diameter side is formed on the outer peripheral surface of the rotating side sealing element.
The inner diameter side end of the set plate is arranged in the annular groove.
The other sealing element of the fixed-side sealing element and the rotating-side sealing element is provided with a sliding member arranged so as to face the set plate in at least one axial and radial direction. ,
The surface of the sliding member is a mechanical seal characterized by having a smaller coefficient of friction than the set plate. The other sealing element is provided with a sliding member arranged so as to face the set plate in at least one axial and radial direction.
The mechanical seal according to claim 1, 2 or 4, wherein the surface of the sliding member has a hardness lower than that of the set plate. A slit extending in the axial direction is formed at the end of the rotating side sealing element.
The mechanical seal according to any one of claims 3 to 6, wherein the diameter of the rotating side sealing element is formed to have a diameter larger than the inner diameter of the set plate. The mechanical seal according to claim 3, wherein a dust seal is provided between the fixed-side sealing element and the rotating-side sealing element. The set plate is attached to the rotating side sealing element and
The mechanical seal according to claim 3 or 5, wherein the set plate is fitted in the annular groove. 1. The mechanical seal according to any one of 9. The set plate is attached to the fixed side sealing element and
The mechanical seal according to any one of claims 1 to 8, wherein the set plate is fixed by bolts. The mechanical seal according to claim 1, wherein the surface of the set plate has a smaller coefficient of friction than the other sealing element.

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