Mechanical seal

Abstract

To provide a mechanical seal including a vibration control member which can stably apply elastic pressing force of an elastic member to sealing rings.SOLUTION: A mechanical seal 1 includes: a pair of sealing ring 5, 60 fixed to a stationary side element Q or a rotary side element R; biasing means 80 which biases the sealing ring 60 to the sealing ring 5; and a vibration control member 10 provided at the sealing ring 60 side. The vibration control member 10 includes: multiple claw-shaped pieces 11 supported by the rotary side element R in a cantilever manner; and an elastic member 15 disposed at a radial space between a tip 12 in the claw-shaped piece 11 and a holding member 8 holding the sealing ring 60.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a mechanical seal for sealing a rotating shaft. [Background technology]

[0002] Mechanical seals are used by being installed between the housing of a fluid equipment and a rotating shaft that passes through the housing. Specifically, mechanical seals have the function of preventing leakage of the sealed fluid by using the biasing force of a biasing means to bring the sliding surfaces of a stationary seal ring attached to the housing into sliding contact with the sliding surface of a rotating seal ring attached to the rotating shaft.

[0003] Some of these mechanical seals are known to be equipped with vibration-damping members to prevent squealing, which occurs when one of the stationary and rotating seal rings, which are held in a cantilevered position, slides radially relative to the other.

[0004] For example, a mechanical seal with a vibration-damping member as disclosed in Patent Document 1 includes a stationary seal ring fixed to a housing, a rotary seal ring fixed to a rotary shaft via a biasing means, and a vibration-damping member fixed to the rotary shaft. One end of the biasing means abuts against a stationary member fixed to the rotary shaft. The other end of the biasing means is held by a retaining member fitted onto the rotary seal ring. The vibration-damping member is composed of a vibration-damping body and an O-ring. The vibration-damping body is formed in a cylindrical shape with a bottom that has an annular bottom and is fitted onto the rotary shaft. The O-ring is disposed in an annular groove formed on the inner diameter side of the end of the vibration-damping body that faces the rotary seal ring.

[0005] This allows the O-ring to elastically deform when the cantilevered rotating seal ring attempts to move relative to the O-ring in the precession or radial direction. This allows the vibration-damping member to prevent excessive movement of the rotating seal ring and continue to hold the axis of the rotating seal ring in approximately the same position. As a result, the vibration-damping member can suppress squealing when the mechanical seal is in use. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2012-26509 A (pages 5 and 6, Figure 1) Summary of the Invention [Problem to be solved by the invention]

[0007] In the mechanical seal of Patent Document 1, the vibration-damping body of the vibration-damping member is configured to surround the rotary seal ring, so that it can be retrofitted to an existing mechanical seal.

[0008] However, the vibration-damping body of the vibration-damping member is configured to surround the rotary seal ring side along the circumferential direction. Therefore, when the vibration-damping member is fitted onto the rotary seal ring side, the O-ring is clamped between the vibration-damping body and the retainer. This can cause a portion of the O-ring to become twisted in the circumferential direction or to be subjected to axial shear force, potentially resulting in significant residual stress in the O-ring. Furthermore, because the vibration-damping body surrounds the rotary seal ring side, not only is it difficult to visually inspect the O-ring during assembly, but it is also difficult to adjust the O-ring position. These factors result in a problem of uneven pressure distribution of the elastic pressing force of the elastic member applied to the rotary seal ring side.

[0009] The present invention has been made in view of these problems, and has as its object to provide a mechanical seal equipped with a vibration-damping member that can stably apply the elastic pressing force of an elastic member to a seal ring. [Means for solving the problem]

[0010] In order to solve the above problems, the mechanical seal of the present invention comprises: A mechanical seal comprising a pair of seal rings fixed to a stationary element or a rotating element, a biasing means for biasing one of the pair of seal rings toward the other, and a vibration damping member provided on one of the seal rings, The vibration-damping member has a plurality of claw-shaped pieces supported in a cantilever manner on the stationary side element or the rotating side element, and an elastic member arranged radially between the tips of the claw-shaped pieces and one of the seal rings or a retaining member that holds the seal ring. According to this, each claw-shaped piece is supported as a cantilever, and its tip is allowed to move in the radial direction. Therefore, the vibration damping member makes it easy to position the elastic member in the desired shape and at the assembly position. This allows the vibration damping member to stably apply the elastic pressing force of the elastic member to one of the seal rings. Furthermore, the vibration damping member can efficiently dissipate heat through the gaps between the claw-shaped pieces.

[0011] The vibration-damping member may include a plurality of the claw-shaped pieces, each having a support base end. According to this, since the support base ends of the claw-shaped pieces are supported while being spaced apart in the circumferential direction, the vibration-damping member can easily form the elastic member into a desired shape.

[0012] The claw-shaped piece may have a groove for fitting the elastic member therein. This allows the elastic member to be held more stably.

[0013] The elastic member may have a curved cross section on the outer side of the groove. This allows the outer contact surface of the elastic member to have good sliding properties, so that one seal ring can smoothly follow the other seal ring.

[0014] The elastic member may be an endless ring. This allows the vibration-damping member to utilize the circumferential tension of the elastic member to damp the vibration of one of the seal rings. This allows the vibration-damping member to more stably apply the elastic pressing force of the elastic member to the one of the seal rings. Furthermore, the vibration-damping member makes it easier to dissipate heat from the elastic member exposed in the gaps between the claw-shaped pieces.

[0015] The claw-shaped piece may be formed in an arc shape so as to fit along the one seal ring or the retaining member. This increases the strength of the claw-shaped piece against radial forces from one of the seal rings or the retaining member, thereby enabling the vibration damping member to more stably apply the elastic pressing force of the elastic member to one of the seal rings.

[0016] The one seal ring may be fixed to the rotating element. In this way, the vibration damping member rotates to promote heat exchange with the surrounding fluid, thereby achieving a higher cooling effect.

[0017] The vibration-damping member may be supported by a fixed member that is urged by the urging means on the side opposite to the one seal ring and is fixed to the rotary shaft. With this, since the vibration-damping member is supported by the fixed member, the radial distance from the rotary shaft to the claw-shaped piece can be made short, and the axial dimension of the vibration-damping member can be made short. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view showing a mechanical seal according to a first embodiment of the present invention. [Figure 2] 1 is a view of the mechanical seal of the first embodiment as seen from the axial direction. [Figure 3] FIG. 3 is a perspective view of a claw-shaped piece in the vibration damping member of the first embodiment. [Figure 4] FIG. 2 is an enlarged view showing a main part of the mechanical seal of the first embodiment. [Figure 5] FIG. 10 is a view of a mechanical seal according to a second embodiment of the present invention as viewed from the axial direction. [Figure 6] FIG. 10 is a perspective view showing a part of a vibration-damping body in a vibration-damping member according to a second embodiment. [Figure 7] FIG. 10 is a view of a mechanical seal according to a third embodiment of the present invention as viewed from the axial direction. [Figure 8] FIG. 10 is an enlarged cross-sectional view showing another example of the elastic member. [Figure 9] FIG. 10 is an enlarged cross-sectional view showing yet another example of the elastic member. [Figure 10] FIG. 10 is an enlarged cross-sectional view showing another example of the arrangement of the elastic members. [Figure 11] FIG. 10 is an enlarged cross-sectional view showing yet another example of the arrangement of the elastic members. DETAILED DESCRIPTION OF THE INVENTION

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A mechanical seal according to the present invention will be described below with reference to the following examples. [Example]

[0020] A mechanical seal according to a first embodiment will be described with reference to Figures 1 to 4. In the following description, the left side of the paper in Figure 1 will be referred to as the left side, and the right side of the paper will be referred to as the right side.

[0021] As shown in Figure 1, the mechanical seal 1 of this embodiment is used in the field of shaft sealing for pumps, mixers, etc. The mechanical seal 1 is attached to provide a seal between a housing 2 and a rotating shaft 3.

[0022] The mechanical seal 1 is mainly composed of a stationary element Q fixed to a housing 2, a rotating element R fixed to a rotating shaft 3, and a vibration damping member 10.

[0023] The stationary element Q includes a case 4 and a stationary seal ring 5. The rotating element R includes a bellows 6 having a rotary seal ring 60, a clamp 7 as a fixing member, a retainer 8 as a holding member, a coil spring 80 as a biasing means, and a set ring 9. A vibration damping member 10 is provided on the rotating element R.

[0024] The stationary seal ring 5 is disposed between a case 4 fixed to the housing 2 in a non-rotating state and in a state where movement in the axial direction is restricted.

[0025] The bellows 6 is formed in a substantially cylindrical shape and includes, from the right side, a rotary seal ring 60, a bellows portion 61, and a base end portion 62.

[0026] The rotary seal ring 60 slides relative to the stationary seal ring 5. The stationary seal ring 5 and the rotary seal ring 60 are ceramic molded products that are low-friction members.

[0027] The stationary seal ring 5 and the rotating seal ring 60 are not limited to being made of ceramics, but may be made of SiC (hard material) and SiC (hard material) and a combination of SiC and carbon (soft material). Any sliding material used for mechanical seals can be used. Examples of SiC include sintered bodies using boron, aluminum, carbon, or other sintering aids, as well as materials consisting of two or more phases with different components and compositions, such as SiC with dispersed graphite particles, reaction-sintered SiC consisting of SiC and Si, SiC-TiC, and SiC-TiN. Examples of carbon include a mixture of carbonaceous and graphite materials, resin-molded carbon, and sintered carbon. In addition to the above sliding materials, metal materials, resin materials, surface-modified materials (coating materials), and composite materials can also be used.

[0028] The bellows portion 61 is formed in a bellows shape and is configured to be expandable and contractible in the axial direction. The base end portion 62 is configured in a cylindrical shape. The inner diameter of the base end portion 62 is approximately the same as the outer diameter of the rotating shaft 3. The bellows portion 61 and the base end portion 62 are molded metal or resin parts, and the bellows portion 61 is adhesively fixed to the rotary seal ring 60.

[0029] The bellows portion 61 may be fixed by any known fixing method other than adhesion, such as welding, shrink fitting, etc. The bellows portion 61 and the rotary seal ring 60 may be integrally molded from the same material, and the configuration of the bellows 6 may be changed as appropriate.

[0030] As shown in Figure 2, the clamp 7 is composed of a pair of split clamp pieces 70 and two bolts 71. The split clamp pieces 70 are formed in a semicircular arc shape. In Figure 2, the set ring 9 is shaded to clearly show the split clamp pieces 70.

[0031] The clamp 7 has a pair of split clamp pieces 70 fitted onto the base end 62 (see FIG. 1) of the bellows 6 and fastened together with two bolts 71, thereby crimping the base end 62 to the rotating shaft 3 and fixing it in a sealed state. Note that, although not shown in detail, by fastening the split clamp pieces 70 together, the clamp 7 is fixed to the set ring 9 in a state where its relative movement is restricted.

[0032] Further, the clamp 7 has an outer peripheral surface 7a with four equally spaced female screw holes 7b recessed on the inner diameter side and opening toward the outer diameter side.

[0033] Returning to Fig. 1, an annular adapter 72 that constitutes the rotating element R is fixed to the clamp 7. Preferably, the adapter 72 is made up of multiple pieces that are divided in the circumferential direction. A rotation prevention pin (not shown) is also fixed to the clamp 7.

[0034] The retainer 8 is formed in a cylindrical shape with a stepped inner diameter side. An outer peripheral surface 8a of the retainer 8 is provided substantially concentrically with the outer peripheral surface 7a of the clamp 7.

[0035] The inner diameter side of the right end of the retainer 8 is expanded so that the rotary seal ring 60 can be fitted inside. Furthermore, relative rotation between the retainer 8 and the rotary seal ring 60 is restricted by anti-rotation means. In this embodiment, the right end of the retainer 8 is formed with a notch that penetrates radially and opens to the right in the axial direction, and into this notch is inserted the head of an anti-rotation pin that is fixed to the rotary seal ring 60 and protrudes outward. Note that the configuration of the anti-rotation means may be modified as appropriate.

[0036] A plurality of recesses that are recessed in the axial direction and open toward the left are formed on the left end surface of the retainer 8. One end of the coil spring 80 is inserted into one of the recesses, and the coil spring 80 is disposed between the retainer 8 and the adapter 72 in an axially compressed state.

[0037] Furthermore, relative rotation between the clamp 7 and the retainer 8 is restricted by anti-rotation means. In this embodiment, one end of an anti-rotation pin (not shown) fixed to the clamp 7 is inserted into another recess in the retainer 8. The configuration of the anti-rotation means may be changed as appropriate.

[0038] As a result, the retainer 8 is allowed to move in the axial direction, and rotates together with the clamp 7 in response to the rotation of the rotary shaft 3. In addition, the rotary seal ring 60, which is biased by the coil spring 80, is kept in an appropriately tight contact with the stationary seal ring 5.

[0039] The set ring 9 is formed in a cylindrical shape. The set ring 9 is fixed to the rotating shaft 3 by a set screw 90 that is threaded into a female screw hole that penetrates the set ring 9 in the radial direction and is pressed against the rotating shaft 3. The set ring 9 restricts the clamp 7 from moving in the axial and rotational directions relative to the rotating shaft 3.

[0040] As shown in FIG. 2, the vibration damping member 10 is mainly composed of four claw-shaped pieces 11 and one O-ring 15 as an elastic member.

[0041] As shown in Fig. 2, the claw-shaped pieces 11 are rigid metal molded parts, and are formed into plates that are curved in an arc along the outer peripheral surface 7a of the clamp 7. As shown in Fig. 3, the claw-shaped pieces 11 are rectangular and extend in the axial direction. Note that the claw-shaped pieces 11 may be made of any rigid material that is not easily elastically deformed, and may also be made of resin molded parts.

[0042] 3 and 4, the claw-shaped piece 11 has, from the right side, a tip 12, a central portion 13, and a terminal end 14. The terminal end 14 serves as a support base end at which the claw-shaped piece 11 is cantilevered.

[0043] On the inner diameter side of the tip 12, a groove 12b is formed that is recessed from the inner peripheral surface 12a toward the outer diameter side, has a rectangular cross section that is open toward the inner diameter side, and is arc-shaped and extends along the circumferential direction. The groove 12b also penetrates the tip 12 in the circumferential direction.

[0044] A through hole 14b penetrating in the radial direction is formed in the circumferential center of the end 14. Furthermore, a counterbore 14c aligned with the through hole 14b is formed on the outer diameter side of the end 14.

[0045] Further, a flange 14d is formed at the left end of the terminal end 14 so as to protrude inward like a eaves.

[0046] 2, O-ring 15 has longitudinal ends 15a and 15b joined together to form a ring shape. Note that the O-ring may have its ends joined together at two or more locations, and this may be modified as appropriate.

[0047] Next, a method for assembling the vibration damping member 10 to the rotating element R will be described. First, referring to Figure 2, an endless annular O-ring is cut into a string shape, which is then wrapped around the retainer 8 at a predetermined axial position, and the ends 15a, 15b are engaged and joined to form the endless annular O-ring 15. In this way, the O-ring 15 can be easily fitted onto the retainer 8 and can also be retrofitted to the mechanical seal 1.

[0048] Next, as shown in Fig. 4, the end 14 of the claw-shaped piece 11 is fixed to the clamp 7. More specifically, first, the through hole 14b of the end 14 is aligned with the female screw hole 7b (see Fig. 2) of the clamp 7. At this time, the flange 14d of the end 14 is engaged with the clamp 7, thereby enabling alignment in the axial direction.

[0049] Next, the bolt 17 is screwed into the female threaded hole 7b with the washer 16 interposed therebetween. While the bolt 17 is being screwed in, if necessary, the position of the O-ring 15 is adjusted so that the O-ring 15 is fitted into the groove 12b at the tip 12.

[0050] Then, the bolt 17 is tightened to fasten the terminal end 14 and the clamp 7. At this time, the movement of the claw-shaped piece 11 is restricted by the flange 14d that is engaged with the clamp 7. This makes it easy to screw in the bolt 17. Furthermore, the O-ring 15, which had a circular cross section before assembly, receives a radial pressing force and becomes roughly stadium-shaped with straight inner and outer diameter sides.

[0051] Furthermore, inner peripheral surface 14a of end 14 is formed along outer peripheral surface 7a of clamp 7. As a result, inner peripheral surface 14a of end 14 is in face-to-face contact with outer peripheral surface 7a of clamp 7. Therefore, the assembly strength to clamp 7 is high.

[0052] The other claw-shaped pieces 11 are also fixed to the clamp 7 using the procedure described above. In addition, since each claw-shaped piece 11 is a separate piece, the position of the groove 12b at the tip 12 of each claw-shaped piece 11 and the O-ring 15 can be adjusted individually, and each claw-shaped piece 11 can be retrofitted to the mechanical seal 1.

[0053] Furthermore, the O-ring 15 and each of the claw-shaped pieces 11 can be attached separately. Therefore, when each of the claw-shaped pieces 11 is fastened to the clamp 7, only a force is applied from the claw-shaped piece 11 to the O-ring 15 in a substantially radial direction, so that the O-ring 15 is not subjected to torsion or axial shear force, making it easier to shape the O-ring 15 into the desired shape after fastening.

[0054] For this reason, compared to the configuration in which an elastic member is placed in a predetermined position while being clamped between the vibration-damping body and the retainer during assembly, as in Patent Document 1, the vibration-damping member 10 can prevent the O-ring 15 from being subjected to loads such as wear and twisting.

[0055] As described above, the O-ring 15 is disposed radially between the tip 12 of each claw-shaped piece 11 and the retainer 8, and the vibration damping member 10 can be assembled to the rotating element R. Note that the procedure for assembling the vibration damping member 10 to the rotating element R may be changed as appropriate.

[0056] For example, the claw-shaped piece 11 may be first supported and fixed to the clamp 7, and then the O-ring 15 may be inserted and placed in the groove 12b of the claw-shaped piece 11. In this case, it is preferable to place the O-ring 15 in a state where the claw-shaped piece 11 is temporarily fixed to the clamp 7, and then further tighten the bolt 17 to permanently fix the claw-shaped piece 11 to the clamp 7.

[0057] As described above, in the vibration damping member 10 of this embodiment, each of the claw-shaped pieces 11 is cantilevered by the clamp 7. Therefore, the tips 12 of the claw-shaped pieces 11 are allowed to move in the radial direction. As a result, even after the claw-shaped pieces 11 are fully fixed to the clamp 7, the O-ring 15 can be released from its twisted state and from being subjected to axial shear force, and can be returned to its intended shape at the assembled position. As a result, the vibration damping member 10 can stably apply the elastic pressing force of the O-ring 15 to the rotary seal ring 60.

[0058] As a result, the vibration damping member 10 allows the O-ring 15 to elastically deform appropriately in accordance with the precession and relative radial movement of the rotary seal ring 60, which is held in a cantilevered manner. As a result, the vibration damping member 10 can suppress excessive movement of the rotary seal ring 60 and continue to hold the axis of the rotary seal ring 60 in approximately the same position. In other words, the vibration damping member 10 can stably suppress squeal when the mechanical seal 1 is in use.

[0059] Furthermore, the vibration damping member 10 can efficiently dissipate heat generated by relative sliding between the stationary seal ring 5 and the rotary seal ring 60 through the gaps S1 between the claw-shaped pieces 11 (see FIG. 2).

[0060] Furthermore, the vibration damping member 10 has gaps S1 (see FIG. 2) formed between each of the claw-shaped pieces 11. By using the gaps S1, it is possible to access the O-ring 15 and the claw-shaped pieces 11 while visually checking the installation state of the O-ring 15, and to appropriately adjust the position of the O-ring 15 relative to the tip 12 of each claw-shaped piece 11, thereby adjusting the degree of crimping of the O-ring 15.

[0061] Furthermore, the ends 14 of the four claw-shaped pieces 11 are spaced apart in the circumferential direction and fixed to the clamp 7. This allows the vibration damping member 10 to adjust the force applied to the O-ring 15 in the approximately radial direction for each claw-shaped piece 11. Therefore, the vibration damping member 10 can easily shape the O-ring 15 into the desired shape.

[0062] Furthermore, because each claw-shaped piece 11 is a separate member, it can be easily fixed to the clamp 7. In a configuration in which the base end 62 of the bellows 6 is fastened by a pair of divided clamp pieces 70 as in this embodiment, differences in the external dimensions of the clamp 7 are likely to occur, and therefore, as will be described later, it is easier to fix to the clamp 7 than a vibration damper 118 having an annular terminal end 114.

[0063] Furthermore, the O-ring 15, which is an endless annular shape, can utilize its circumferential tension to damp vibration of the rotary seal ring 60. This allows the elastic pressing force of the O-ring 15 to be applied to the rotary seal ring 60 more stably.

[0064] In addition, the position of the O-ring 15 relative to the tip 12 of each claw-shaped piece 11 can be adjusted by, for example, directly gripping a portion of the O-ring 15 exposed in the gap S1 (see FIG. 2) between each claw-shaped piece 11. This makes it possible to omit or simplify adjustments using jigs or the like, making position adjustments easier.

[0065] Furthermore, a portion of the O-ring 15 is exposed in the gap S1 (see FIG. 2) between each of the claw-shaped pieces 11. This makes it easier to cool the O-ring 15. This allows the vibration damping member 10 to effectively prevent the O-ring 15 from deteriorating, melting, or the like due to high temperatures.

[0066] Furthermore, the rectangular claw-shaped piece 11 has a substantially constant width in the circumferential direction from the end 14 to the tip 12. As a result, when a radial force acts from the O-ring 15 on the tip 12 of the claw-shaped piece 11, the claw-shaped piece 11 is less likely to twist, and can receive the force in a distributed manner in the circumferential direction.

[0067] Furthermore, the tip 12 of the claw-shaped piece 11 is allowed to move in the radial direction, with the end 14 fixed to the clamp 7 as the base point. This makes it easier to ensure the allowable amount of movement compared to the claw-shaped piece 111 (see FIG. 6) of the vibration damper 118 described below.

[0068] Furthermore, the inner circumferential surface 12a of the tip 12 of the claw-shaped piece 11 is formed to be located slightly radially outward of the inner circumferential surface 14a of the end 14. Therefore, in the natural state of the mechanical seal 1, a gap S2 (see FIG. 4) is formed between the inner circumferential surface 12a of the tip 12 and the outer circumferential surface 8a of the retainer 8. By ensuring an allowance for elastic deformation of the O-ring 15 in this way, the claw-shaped piece 11 can stably apply the elastic pressing force of the O-ring 15 to the rotary seal ring 60. Note that as long as the gap S2 is formed, the outer diameter of the retainer may be smaller than the outer diameter of the clamp, and the configuration may be modified as appropriate.

[0069] Furthermore, through the gaps S1 (see FIG. 2) between the claw-shaped pieces 11 and the gaps S2 (see FIG. 4) between the tips 12 of the claw-shaped pieces 11 and the retainer 8, the portions of the O-ring 15 fitted into the grooves 12b can be accessed from both axial sides of the rotating shaft 3. This improves the accuracy of positioning the O-ring 15 relative to the tips 12 of the claw-shaped pieces 11.

[0070] Additionally, the O-ring 15 fitted into the groove 12b bulges outward from the groove 12b toward the retainer 8, forming a curved cross section. This improves the sliding properties of the contact surface of the O-ring 15 that contacts the retainer 8. This allows the rotating seal ring 60 to smoothly follow the stationary seal ring 5.

[0071] Furthermore, the claw-like pieces 11 are formed in an arc shape so as to follow the outer peripheral surface 8a of the retainer 8. This increases the strength of the claw-like pieces 11 against the radial forces received from the rotary seal ring 60 and the O-ring 15. This allows the elastic pressing force of the O-ring 15 to be applied to the rotary seal ring 60 more stably.

[0072] Furthermore, the inner peripheral surface 13a of the central portion 13 of the claw-shaped piece 11 is formed so as to be located radially outward of the inner peripheral surfaces 12a, 14a of the leading end 12 and trailing end 14. In addition, the central portion 13 is located radially outward of the gap between the clamp 7 and the retainer 8. This makes it difficult for the central portion 13 to come into contact with the clamp 7 and the retainer 8 even if their respective axes tilt relative to one another. This allows the elastic pressing force of the O-ring 15 to be stably and continuously applied to the rotary seal ring 60.

[0073] The circumferential dimension of the claw-shaped pieces 11 is equal to or less than twice the circumferential dimension of the gap S1 (see FIG. 2) between the claw-shaped pieces 11, i.e., the distance between adjacent claw-shaped pieces 11, 11. This allows the tips 12 of each claw-shaped piece 11 to move radially.

[0074] Furthermore, the vibration-damping member 10 not only improves visibility of the O-ring 15 and provides the working space necessary for adjusting the position of the O-ring 15, but also increases the efficiency of cooling the O-ring 15 that is exposed in the wide gaps S1 between each of the claw-shaped pieces 11.

[0075] Furthermore, the vibration damping member 10 fixed to the rotating element R rotates to promote heat exchange with the surrounding fluid, thereby achieving a higher cooling effect.

[0076] Furthermore, the vibration-damping member 10 is supported by the clamp 7. Therefore, the claw-shaped pieces 11 fixed to the clamp 7 have a shorter radial distance from the rotating shaft 3 to each claw-shaped piece 11, and the axial dimension of the vibration-damping member 10 can be made shorter, compared to a configuration in which the claw-shaped pieces 11 are fixed to the rotating shaft 3 and extend toward the rotary seal ring 60, passing further outwardly than the clamp 7.

[0077] As a result, the vibration damping member 10 not only reduces the centrifugal force acting on the cantilevered claw-shaped pieces 11 due to rotation, but also shortens the moment arm of the force acting radially from the rotary seal ring 60.

[0078] Furthermore, since the claw-shaped piece 11 fixed to the clamp 7 is separate from the set ring 9, compared to a configuration that combines the function of fixing itself to the rotating shaft 3 and fixing the bellows 6 to the rotating shaft 3, it is possible to easily adjust the degree of crimping of the O-ring 15 while reliably restricting the base end 62 of the bellows 6 from moving in the axial and rotational directions.

[0079] Furthermore, the O-ring 15 has a cross-sectional shape that is round at the portion located in the gap S1 between the claw-shaped pieces 11 (see FIG. 2), and a cross-sectional shape that is generally stadium-shaped at the portion pressed against the claw-shaped pieces 11, with these cross-sectional shapes arranged alternately. Therefore, even if the O-ring 15 attempts to move circumferentially relative to each claw-shaped piece 11, the portion located in the gap S1 is likely to be locked into the groove 12b of the claw-shaped piece 11. For this reason, compared to the configuration of Patent Document 1, in which the O-ring is pressed radially over substantially the entire circumference and has a generally uniform cross-sectional shape, the O-ring 15 of this embodiment is less likely to move circumferentially.

[0080] Although the claw-shaped piece 11 has been described as being fixed to the clamp 7 by tightening a bolt 17 with a washer 16 interposed therebetween, this is not limited to this, and the piece may be fixed to the clamp 7 by welding or adhesive, and the fixing means may be changed as appropriate.

[0081] The O-ring does not have to have engageable ends 15a, 15b. Even with this configuration, it can be fitted onto the end of the rotating shaft 3, moved to a predetermined position, and fitted onto the retainer 8. The subsequent procedures are the same as those described above. [Example]

[0082] Next, a mechanical seal according to a second embodiment will be described with reference to Figures 5 and 6. Note that a description of the same configuration as in the first embodiment will be omitted.

[0083] As shown in FIG. 5, the vibration damping member 110 in the mechanical seal 101 of the second embodiment is composed of a vibration damper 118 and an O-ring 115.

[0084] 5 and 6, the vibration damper 118 has a terminal end 114 as an annular support base end, and four equally spaced claw-shaped pieces 111. Each claw-shaped piece 111 has a central portion 13 extending axially from the terminal end 114, and a tip end 12 (see FIG. 6). The O-ring 115 is a continuous O-ring that does not have the end portions 15a and 15b of the first embodiment (see FIG. 5).

[0085] When assembling the vibration-damping member 110 to the rotating-side element R, first, an O-ring 115 is fitted into the groove 12b at the tip 12 of each claw-shaped piece 111. Next, the vibration-damping member 110 is fitted onto the end of the rotating shaft 3 and moved toward the rotary seal ring 60, and the end 114 is fitted onto the clamp 7.

[0086] At this time, each claw-shaped piece 111 is cantilevered by the end 114, and because its circumferential dimension is shorter than the circumferential dimension of the end 114, the tip 12 of the claw-shaped piece 111 is allowed to move radially from the end 114 side of the claw-shaped piece 111. This makes it less likely that the O-ring 115 will be twisted or subjected to axial shear force. Therefore, the O-ring 115 is more likely to be positioned in the desired shape at the assembly position.

[0087] Furthermore, even if a portion of the O-ring 115 becomes twisted in the circumferential direction or is subjected to axial shear force, the gap S11 between each claw-shaped piece 111 can be used to restore the twist, and the position of the O-ring 115 relative to the tip 12 of the claw-shaped piece 111 can be appropriately adjusted to eliminate the shear force.

[0088] Then, after the annular flange 114d is engaged with the clamp 7 to perform axial positioning, the vibration damping member 110 can be attached to the rotating element R by fastening it to the clamp 7 using a washer 16 and a bolt 17.

[0089] Although the vibration damper 118 is integrally formed with the annular terminal end 114 and four equally spaced claw-shaped pieces 111, it may also be configured with one claw-shaped piece 111 or multiple claw-shaped pieces 111, with multiple arc-shaped terminal ends that are longer in the circumferential direction than the claw-shaped piece 111, and this configuration may be changed as appropriate. In such a configuration, the terminal ends may be spaced apart in the circumferential direction. [Example]

[0090] Next, a mechanical seal according to a third embodiment will be described with reference to Fig. 7. Note that a description of the same configuration as in the first embodiment will be omitted.

[0091] The vibration damping member 210 in the mechanical seal 201 of the third embodiment is made up of four equally spaced claw pieces 11 (see FIG. 4) and four packings 215.

[0092] The packing 215 has a circular cross-sectional shape before assembly and is formed like a string extending in the circumferential direction. The packing 215 is fitted into the groove 12b at the tip 12 of the claw-shaped piece 11. It is preferable that the packing 215 be adhered to the groove 12b to prevent it from slipping out of the groove 12b.

[0093] Even with this configuration, the position of the packing 215 relative to the tip 12 of the claw-shaped piece 11 can be adjusted appropriately by utilizing the gap S1 between each of the claw-shaped pieces 11.

[0094] Furthermore, when the mechanical seal 1 is in its natural state, the vibration-damping member 210 can access the packing 215 through a gap S2 (see FIG. 4) formed between the tip 12 of the claw-shaped piece 11 and the retainer 8. Therefore, the groove may be configured so that both circumferential ends are closed to prevent the packing 215 from slipping out in the circumferential direction.

[0095] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention also includes modifications and additions that do not deviate from the gist of the present invention.

[0096] For example, in Examples 1 to 3, the vibration-damping member is described as being provided on the rotating element, but this is not limited to this. The vibration-damping member may be provided on the element on which the biasing member is arranged, and if the biasing member is arranged on the stationary element, the vibration-damping member may be provided on the stationary element.

[0097] In addition, in the above-described first to third embodiments, the vibration-damping member is described as being fixed to a clamp, but this is not limited thereto. The vibration-damping member may be fixed to a set ring, a sleeve inserted around the rotating shaft, or any other suitable rotating element. Furthermore, the vibration-damping member may be fixed to the rotating shaft. This also applies to the case where the biasing member is disposed on the stationary element, and the vibration-damping member may be fixed to one of the stationary elements or to the housing.

[0098] In addition, in the first to third embodiments, the vibration-damping member has been described as having a configuration in which the claw-shaped piece is fixed to a clamp, which is a fixed member, and an elastic member is disposed between the claw-shaped piece and a retainer, which is a holding member, but this is not limited thereto, and the claw-shaped piece may be supported and fixed to the holding member in a cantilevered state, and an elastic member may be disposed between the claw-shaped piece and the fixed member. This also applies to the case in which the biasing member is disposed on the stationary element.

[0099] Furthermore, if the vibration-damping member is configured to be directly fixed to the rotating shaft, it may also function as a set ring.

[0100] Furthermore, in the above-described Examples 1 to 3, the claw-shaped pieces are described as being arranged in four equal intervals, but this is not limited to this, and the position and number of the pieces may be changed as appropriate as long as multiple pieces are arranged in the circumferential direction.

[0101] Furthermore, in Examples 1 to 3, the radially viewed claw-shaped pieces were described as having a rectangular shape extending in the axial direction, but this is not limited to this, and the central axial portion may be curved toward the outer diameter side or the inner diameter side, or may be wavy, and the shape may be changed as appropriate.

[0102] Furthermore, in the above-described Examples 1 to 3, the axially viewed claw-shaped pieces were described as being curved along the retainer, but this is not limited to this and they may be flat or wavy, and their shape may be changed as appropriate.

[0103] In addition, in the first to third embodiments, the elastic member is configured to be pressed against the retainer, but this is not limiting and the elastic member may be pressed against the rotary seal ring. This also applies to the case where the biasing member is disposed on the stationary element.

[0104] Furthermore, in the above-described first to third embodiments, the elastic member has been described as being an O-ring or a packing having a round cross section, but is not limited to this. For example, it may be elastic member 315 having a rectangular cross section as shown in FIG. 8, or it may be elastic member 415 having a downward-pointing bullet shape in which the portion fitted into groove 12b is formed in a rectangular shape and the portion protruding outside the groove is formed in an arc shape as shown in FIG. 9, and the shape may be changed as appropriate.

[0105] Furthermore, in the first to third embodiments, the elastic member is described as being fitted into a groove at the tip of the claw-shaped piece, but this is not limited thereto, and as shown in Fig. 10, elastic member 515 may be fitted into groove 581 formed in retainer 508, and tip 512 of claw-shaped piece 511 may be flat, or as shown in Fig. 11, elastic member 615 may be sandwiched between flat tip 612 of claw-shaped piece 611 and retainer 8, and any other suitable configuration may be used as long as elastic member 615 is disposed radially between the tip of the claw-shaped piece and one of the seal rings or the retaining member for that seal ring. Note that elastic member 615 in Fig. 11 is preferably adhesively fixed to claw-shaped piece 611 or retainer 8.

[0106] Furthermore, the elastic member may be held in position by adhesion, or an elastic member with a U-shaped cross section may be attached and fixed to the tip of the claw-shaped piece, and the holding means for holding the elastic member may be changed as appropriate.

[0107] In addition, in the first to third embodiments, the rotary seal ring is described as being part of a bellows, but this is not limiting and the rotary seal ring may be a single seal ring without the bellows portion, etc. This also applies to the case where a vibration damping member is applied to a stationary seal ring.

[0108] Furthermore, in the above-described first to third embodiments, the biasing means is described as being a coil spring, but this is not limited to this, and the biasing means may also be a bellows, a coiled wave spring, or rubber, or any combination of these, or may be modified as appropriate. [Explanation of symbols]

[0109] 1 Mechanical seal 2. Housing 3 Rotation Axis 4 Cases (stationary element) 5 Stationary sealing ring 6 Bellows 7 Clamp (rotating element, fixed member) 8 Retainer (rotating element, holding member) 10. Vibration-damping member 11 Nail piece 12 Tip 12b Groove 14 End (support base end) 15 O-ring 60 Rotating seal ring 80 Coil spring (biasing means) 101 Mechanical seal 110 Vibration-damping member 111 Nail piece 114 End (support base end) 115 O-ring 118 Vibration damper 201 Mechanical seal 210 Vibration-damping member 215 Gasket 315,415,515,615 Elastic members 508 Retainer (rotating element, holding member) 581 Groove 511,611 Nail piece 512,612 tips Q Stationary element R Rotation side element S1, S11 gap

Claims

1. A mechanical seal comprising a pair of seal rings fixed to a stationary element or a rotating element, a biasing means for biasing one of the pair of seal rings toward the other, and a vibration damping member provided on one of the seal rings, the vibration-damping member has a plurality of claw-shaped pieces that are cantilevered on the stationary-side element or the rotating-side element, and an elastic member that is arranged radially between the tips of the claw-shaped pieces and the one seal ring or a retaining member that retains the seal ring, The claw-shaped pieces extend in the axial direction, are curved in an arc shape when viewed axially, and are rectangular when viewed radially. This is a mechanical seal.

2. 2. The mechanical seal according to claim 1, wherein the vibration-damping member comprises a plurality of the claw-shaped pieces, each having a support base end.

3. 2. The mechanical seal according to claim 1, wherein the claw-shaped piece has a groove for fitting the elastic member therein.

4. A mechanical seal as described in Claim 3, wherein the elastic member arranged radially between the tip of the claw-shaped piece and one of the sealing rings or a retaining member holding the sealing ring has a portion that has a curved cross section at a location that protrudes radially inward from the groove.

5. 2. The mechanical seal according to claim 1, wherein the elastic member is an endless annular member.

6. 2. The mechanical seal according to claim 1, wherein the claw-shaped piece is formed in an arc shape so as to follow the one of the seal rings or the retaining member.

7. 2. The mechanical seal according to claim 1, wherein the one seal ring is fixed to the rotating element.

8. 8. The mechanical seal according to claim 7, wherein the vibration-damping member is biased by the biasing means on a side opposite to the one seal ring and is supported by a fixed member fixed to the rotary shaft.

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