JP2018179093A - Mechanical seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cool contact portions of both sealing rings without the necessity of a supply source and the supply equipment of a cooling fluid.SOLUTION: A rotating sealing ring 6 arranged at a rotating shaft 4 comprises a main body part 9, and a sealing end face forming part 10 which protrudes from a tip face 9a of the main body part 9 with an outside diameter set smaller than that of the main body part. An external peripheral side fluid region L and an internal peripheral side fluid region H of contact portions 3b, 6a are blocked and sealed by the relative rotation of the contact portions 3b, 6a contacting with the sealing end face forming part 10 and a stationary sealing ring 3 arranged in a seal case 2. A cooling passage 16 penetrating an outlet part 16b which is opened in the vicinity of the sealing end face forming part 10 at a tip face 9b from an inlet part 16a which is opened at an external peripheral face 9a is formed at the main body part 9 of the rotating sealing ring 6, and a fluid in the external peripheral side fluid region L is discharged toward the contact portions 3b, 6a from the outlet part 16b of the cooling passage 16 accompanied by the rotation of the rotating sealing ring 6.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a mechanical seal used as a shaft sealing means of industrial equipment such as a stirrer.

  As a mechanical seal used as a shaft sealing means such as a stirrer, a contact portion between a stationary seal ring provided on a seal case and a rotary seal ring provided on a rotating shaft is relatively rotated, thereby the outer periphery of the contact portion. It is known to be configured to shield and seal the side fluid region and the inner circumferential fluid region.

  Thus, in such a mechanical seal, frictional heat is generated by the relative rotation of the contact portions of both sealing rings, and the frictional heat causes excessive contact heat, which causes the contact portion to be seized, abnormal wear or distortion, or the like. May cause troubles such as

  Therefore, in the conventional mechanical seal, as disclosed in Patent Document 1, a cooling fluid is supplied from the outside to the contact portion of both sealing rings, and the device is designed to cool the contact portion.

WO 2006/022378

  However, since the mechanical seal disclosed in Patent Document 1 requires a supply source and a supply facility of a cooling fluid, the equipment cost and the installation cost are incurred, and the maintenance cost such as the running cost is also high.

  An object of the present invention is to provide a mechanical seal capable of efficiently cooling the contact portion of both sealing rings without requiring such a supply source or supply facility of the cooling fluid. .

  In the present invention, in order to achieve the above object, a rotary sealing ring provided on a rotary shaft has a main body portion, and a sealed end face forming portion having a smaller diameter than the main body portion and projecting from a tip end surface of the main body portion The outer peripheral fluid region and the inner peripheral region of the contact portion are provided by relatively rotating the contact portion between the seal end face forming portion of the rotary seal ring and the stationary seal ring provided in the seal case. The cooling passage is configured to perform shielding sealing, and the cooling passage extends from the inlet opening in the outer peripheral surface to the outlet opening in the vicinity of the sealing end face forming portion in the tip end surface of the rotary sealing ring body. We propose a mechanical seal in which is formed.

  In such a mechanical seal, the main body of the rotary seal ring is provided with a cylindrical cover body which is close to the stationary seal ring and surrounds the outer peripheral area of the seal end face forming portion, or the seal case is Preferably, a cylindrical cover body is provided in proximity to the main body of the rotary sealing ring and surrounding the outer peripheral area of the sealing end face forming part. Furthermore, it is preferable that an annular recess be formed in an outer peripheral region of the contact portion on the tip end surface of the stationary sealing ring so as to face the outlet of the cooling passage.

  According to the mechanical seal of the present invention, the fluid in the outer peripheral fluid region of the contact portion of both seal rings is discharged from the outlet of the cooling passage toward the contact portion as the rotary seal ring rotates. The discharge fluid can effectively cool the contact portion without requiring a cooling fluid source or supply facility. In particular, by providing the cover body on the main body portion or the seal case of the rotary sealing ring and / or forming the annular recess on the distal end surface of the stationary sealing ring, the discharge fluid is contained in the cover body or Since the positive fluid is circulated in the annular recess, the heat exchange between the contact portion of the two seal rings and the discharge fluid is sufficiently performed to cool the contact portion more effectively.

It is a sectional view showing an example of a mechanical seal concerning the present invention. It is detail drawing which expands and shows the principal part of FIG. It is sectional drawing of the principal part which follows the AA of FIG. It is sectional drawing of the principal part of FIG. 2 which shows the modification of the mechanical seal which concerns on this invention. It is sectional drawing of the principal part of FIG. 2 which shows the other modification of the mechanical seal which concerns on this invention. It is sectional drawing of the principal part of FIG. 2 which shows the other modification of the mechanical seal which concerns on this invention. It is sectional drawing of the principal part of FIG. 2 which shows the other modification of the mechanical seal which concerns on this invention. It is sectional drawing of the principal part of FIG. 2 which shows the other modification of the mechanical seal which concerns on this invention.

  Hereinafter, an embodiment for carrying out the present invention will be specifically described based on the drawings.

  FIG. 1 is a cross-sectional view showing an example of a mechanical seal according to the present invention, FIG. 2 is a detailed view showing a main part of FIG. 1 in an enlarged manner, and FIG. 3 is a main part along line A-A in FIG. FIG.

  The mechanical seal shown in FIG. 1 is used as a shaft sealing means of a rotating device such as a stirrer, and is provided on an annular seal case 2 attached to the shaft sealing portion housing 1 of the rotating device and the seal case 2 The rotary shaft disposed between the stationary seal ring 3 and the spring retainer 5 and fixed to the stationary seal ring 3, the spring retainer 5 fixed to the rotary shaft 4 of the rotary device concentrically penetrating the seal case 2, and 4. A rotary seal ring 6 axially movably provided at 4 and an axial direction loaded between the spring retainer 5 and the rotary seal ring 6 to press and contact the rotary seal ring 6 to the stationary seal ring 3 And a spring member 7 for biasing.

  The mechanical seal rotates relative to each other while the stationary seal ring 3 and the rotary seal ring 6 are in contact with each other, so that the inner peripheral fluid region H of the seal end faces 3b and 6a as the contact portion of the two seal rings 3 and 6 It is configured to shield and seal with the side fluid region L. In this example, the mechanical seal is an outside type mechanical seal in which the inner peripheral fluid region H of the sealed end faces 3b and 6a of both sealing rings 3 and 6 is the in-machine region and the outer peripheral fluid region L is the air region. It is done.

  The rotary seal ring 6, as shown in FIG. 1, is an appropriate seal ring material selected according to sealing conditions such as the properties of the fluid in the inner peripheral side fluid region H (hereinafter also referred to as sealed fluid). It is made of a softer material (e.g., carbon etc.) than the stationary seal ring 3. The rotary seal ring 6 includes an annular main body 9, an annular sealing end face forming portion 10 coaxially projecting from the distal end surface 9 b of the main body 9 with the main body 9, and a base of the main body 9. It comprises an annular holding portion 11 concentrically connected to the main body portion 9 at the end face. The rotary seal ring 6 is movably held in the axial direction with respect to the rotary shaft 4 with the O-ring 12 interposed between the holding portion 11 and the rotary shaft 4.

  An annular end face forming portion 10 of the rotary sealing ring 6 has an outer diameter smaller than the outer diameter of the main body 9 and an inner diameter equal to the inner diameter of the main body 9 or larger than the inner diameter of the main body 9 Part of A sealed end face 6a formed at the tip of the sealed end face forming portion 10 is formed in a ring-shaped smooth plane whose entire surface is orthogonal to the axial direction.

  The outer diameter of the holding portion 11 of the rotary seal ring 6 is set to be equal to or smaller than the outer diameter of the main body portion 9, and the inner diameter is set to be larger than the inner diameter of the main body portion 9. It is an annular part. A holding ring 13 having a substantially L-shaped cross section is fitted in the holding portion 11.

  The holding ring 13 is an integral structure comprising a cylindrical portion 13 a fitted to the outer peripheral surface of the holding portion 11 of the rotary sealing ring 6 and an annular plate portion 13 b in contact with the base end of the holding portion 11. . The holding ring 13 prevents the relative rotation with respect to the rotary sealing ring 6 by engaging the drive pin 14a attached to the annular plate portion 13b with the engagement hole 11a formed at the base end of the holding portion 11 It is done.

  The stationary seal ring 3 is an annular body made of a material harder than the rotary seal ring 6 such as ceramics such as silicon carbide or cemented carbide as shown in FIG. It is fitted and fixed via O-rings 8 and 8. The distal end surface 3a of the stationary seal ring 3 is formed such that the outer diameter thereof is larger than the outer diameter of the sealed end surface 6a of the rotary seal ring 6, and the inner diameter thereof is formed smaller than the inner diameter of the sealed end surface 6a. The distal end surface 3a of the stationary seal ring 3 is formed in an annular smooth surface orthogonal to the axial direction. A seal end face 6a of the rotary seal ring 6 is in contact with the end face 3a, and a seal end face 3b having the same inner and outer diameters as the seal end face 6a is formed.

  The spring retainer 5 is inserted between the holding portion 11 of the rotary seal ring 6 and the rotary shaft 4 so as to protrude from the inner peripheral side of the annular portion 5a fixed to the rotary shaft 4 by the set screw 15 It is a cylindrical integral component comprising the cylindrical portion 5b. The O-ring 12 is loaded in an annular space surrounded by the holding portion 11 of the rotary seal ring 6, the rotary shaft 4 and the main body portion 9 of the rotary seal ring 6, and the cylindrical portion 5b of the spring retainer 5. In the annular portion 5a of the spring retainer 5, an insertion hole 5c is formed through which the drive pin 14b attached to the holding ring 13 is inserted. By inserting the drive pin 14b into the insertion hole 5c, relative rotation of the rotary seal ring 6 with respect to the rotary shaft 4 is prevented while permitting movement of the rotary seal ring 6 in the axial direction within a predetermined range.

  The spring member 7 is a plurality of coil springs (only one is shown in FIG. 1) loaded between the annular portion 5 a of the spring retainer 5 and the annular plate portion 13 b of the retaining ring 13. The sealing end face 6a of the rotary sealing ring 6 is brought into contact with the sealing end face 3b of the stationary sealing ring 3 by urging the rotary sealing ring 6 to press the stationary sealing ring 3 on the other hand.

  Thus, the main body 9 of the rotary seal ring 6 is formed with an inlet 16a opening at the outer peripheral surface 9a, and is opened from the inlet 16a to the vicinity of the sealing end face forming portion 10 at the distal end surface 9b. A plurality of cooling passages 16 penetrating to the outlet portion 16 b are formed at equal intervals in the circumferential direction of the main body portion 9.

  In each of the cooling passages 16, as shown in FIG. 2, the fluid F in the outer peripheral fluid region L flows into the cooling passage 16 from the inlet portion 16 a as the rotary seal ring 6 rotates, and the inside of the cooling passage 16 is discharged After moving toward the portion 16 b, the discharge is carried out from the outlet portion 16 b toward the sealed end faces 3 b, 6 a of the both seal rings 3, 6. In this example, the cooling passage 16 is a through hole having a circular cross section formed linearly so as to form the inclination angle shown in FIGS. 2 and 3. A circular inlet 16a and an outlet 16b are formed.

  That is, as shown in FIG. 2, each cooling passage 16 is formed such that the outlet portion 16b is inclined by a predetermined angle α in the inner circumferential direction of the rotary seal ring 6 with respect to the inlet portion 16a. As shown in the drawing, the inlet 16a is a plane passing through the center line of the rotary seal ring 6, and the inlet 16a is in the rotational direction of the rotary seal 6 (rotational direction of the rotary shaft 4) It is formed so as to have a tilt angle which is biased by a predetermined angle β. Here, α is preferably 5 ° or more and 45 ° or less. Further, β is preferably 10 ° or more and 75 ° or less, and more preferably 40 ° or more and 75 ° or less.

  In the mechanical seal configured as described above, when the rotary seal ring 6 rotates, the fluid (for example, air or water) F in the outer peripheral fluid region L is taken into the cooling passage 16 from the inlet portion 16a. Then, it is discharged from the outlet portion 16 b toward the sealing end faces 3 b and 6 a of the both seal rings 3 and 6. The sealed end faces 3b and 6a are cooled by contact with the fluid (hereinafter, also referred to as a discharged fluid F) discharged from the outlet 16b of the cooling passage 16 and cooled. As a result, the occurrence of troubles such as seizure due to frictional heat at the sealed end faces 3b and 6a, abnormal wear and generation of distortion, and the like can be prevented.

  Hereinafter, other embodiments will be described. Cooling of the sealed end faces 3b and 6a of the both seal rings 3 and 6 by the fluid F discharged from the outlet portion 16b of the cooling passage 16 is more effectively achieved, for example, by devising as shown in FIGS. It can be carried out.

  That is, as shown in FIG. 4, the seal of both sealing rings 3 and 6 is opposed to the outlet portion 16b of the cooling passage 16 at the end face 3a of the stationary sealing ring 6 and on the outer peripheral side of the sealing end face 3b. An annular recess 17 is formed to surround the outer peripheral area of the end faces 3b and 6a. By forming such an annular recess 17, the fluid F discharged from the outlet portion 16 b of the cooling passage 16 is, as shown in FIG. 4, the annular recess 17 from the sealing end faces 3 b and 6 a of both sealing rings 3 and 6. It enters inside and becomes a circulating flow toward the rotary seal ring 6, and the contact time between the discharge fluid F and the seal end faces 3b, 6a increases. As a result, heat exchange between the sealed end faces 3b, 6a and the discharge fluid F is performed better, and cooling of the sealed end faces 3b, 6a by the discharged fluid F is performed more effectively.

  The annular recess 17 has an inner circumferential surface 17a whose diameter gradually expands toward the opening (the rotary sealing ring 6 side) of the recess 17 and an outer circumferential surface 17b whose diameter gradually expands toward the opening of the annular recess 17 And the connecting surface connecting the inner peripheral surface 17a and the outer peripheral surface 17b, the flow of the discharge fluid F in the annular recess 17 is performed more smoothly.

  Further, as shown in FIG. 5, the main body 9 of the rotary seal ring 6 is a cylindrical cover that surrounds the outer peripheral region of the seal end face forming portion 10 of the rotary seal ring 6 in a state of being close to the stationary seal ring 3. A body 18 is provided. In this example, the cylindrical portion 13 a of the holding ring 13 is extended to the vicinity of the end face 3 a of the stationary sealing ring 3, and the extended portion is integrally formed with the cover 18. The cover 18 is formed with a through hole 18 a connecting the inlet portion 16 a of each cooling passage 16 and the outer peripheral fluid region L. The through hole 18 a is an opening for taking in the fluid in the outer peripheral fluid region L and flowing it toward the cooling passage 16.

  By providing such a cover body 18, the discharge fluid F from the outlet portion 16 b of the cooling passage 16 is discharged from the sealing end faces 3 b and 6 a of the both sealing rings 3 and 6 between the cover body 18 and the stationary sealing ring 3. The fluid positively flows into the gap 18b, and the discharge fluid F is circulated by repetition of this flow. From this, the contact between the discharged fluid F and the sealed end faces 3b and 6a is sufficiently performed, and the sealed end faces 3b and 6a are cooled more effectively. The cover body 18 is not an extension of the cylindrical portion 13 a of the holding ring 13, and may be attached to the main body 9 of the rotary seal ring 6 separately from this. In this case, the cover body 18 can be a two-piece structure configured to attach two semi-cylindrical members in a cylindrical shape to the main body 9 of the rotary seal ring 6.

  Further, as shown in FIG. 6, a cylindrical cover body surrounding the outer peripheral region of the seal end face forming portion 10 of the rotary seal ring 6 in the state close to the main body 9 of the rotary seal ring 6 in the seal case 2. 19 are attached via the fastening means. By providing such a cover body 19, as in the case where the cover body 18 is provided, the discharge fluid F from the outlet portion 16 b of the cooling passage 16 is the sealing end face 3 b of the both sealing rings 3, 6, 6a actively flows into the gap 19a between the cover body 19 and the main body 9 of the rotary seal ring 6, and the discharge fluid F is circulated by repeating this flow. From this, the contact between the discharged fluid F and the sealed end faces 3b and 6a is sufficiently performed, and the sealed end faces 3b and 6a are cooled more effectively. In addition, the cover body 19 can be made into the 2 part structure comprised so that two semi-cylindrical members could be made into cylindrical shape, and it could attach to the main-body part 9 of the rotary sealing ring 6.

  Furthermore, in the one shown in FIG. 7 or FIG. 8, the annular recess 17 and the cover body 18 or the cover body 19 are combined, and both sealing rings 3, 6 by the discharge fluid F from the outlet 16b of the cooling passage 16 are provided. Cooling of the sealed end faces 3b, 6a of the present invention is performed more effectively.

  That is, in the one shown in FIG. 7, both the seal rings 3 from the outlet portion 16 b by the cover body 18 projecting from the main body 9 of the rotary seal ring 6 and the annular recess 17 formed in the distal end surface 3 a of the stationary seal ring 3. , 6 are more strongly directed to the sealed end faces 3b, 6a, and cooling of the sealed end faces 3b, 6a by the discharged fluid F is extremely effectively performed.

  Further, in the one shown in FIG. 8, the sealing end face of both sealing rings 3 and 6 from the outlet portion 16 b by the cover body 19 protruding from the seal case 2 and the annular recess 17 formed in the tip surface 3 a of the stationary sealing ring 3. The flow of the discharge fluid F toward 3b and 6a is performed more strongly, and the cooling of the sealed end faces 3b and 6a by the discharge fluid F is performed extremely effectively.

  The configuration of the present invention is not limited to the above-described embodiments, and can be appropriately improved or changed without departing from the basic principle of the present invention.

  For example, in each of the above embodiments, the present invention is applied to an outside type mechanical seal in which the outer peripheral side fluid region L is an unsealed fluid region, and the fluid in the unsealed fluid region is a sealed end face of both sealing rings 3 and 6 The present invention is applied to an inside type mechanical seal in which the outer peripheral side fluid region of the sealed end faces 3b, 6a becomes a sealed fluid region (in-machine region), though it is used as the discharge fluid F which is a cooling fluid of 3b, 6a. It is also possible to use the sealed fluid (process fluid) as the discharge fluid F, which is a cooling fluid for the sealed end faces 3b and 6a, regardless of whether it is a gas or a liquid. Further, each cooling passage 16 is not limited to the above-described linear shape. For example, an opening is formed from the outer peripheral surface 9a of the main body 9 toward the rotary shaft 4 and an opening is formed from the distal end surface 9b of the main body 9 toward the retaining ring 13, and communication is made at the intersection of both openings. It is good also as what makes the broken line shape which it did. By doing so, the formation and processing of each cooling passage 16 can be easily performed.

Reference Signs List 2 seal case 3 static seal ring 3a tip end face 3b seal end face 4 rotary shaft 6 rotary seal ring 6a seal end face 9 main body 9a outer peripheral face 9b tip end face 10 seal end face forming portion 16 cooling passage 16a inlet portion 16b outlet portion 17 annular recess 18 Cover body 19 cover body F fluid H inner peripheral fluid region L outer peripheral fluid region

Claims (4)

The rotary seal ring provided on the rotary shaft comprises a main body portion, and a sealed end face forming portion smaller in diameter than the main body portion and projecting from the tip end surface of the main body portion,
The contact portion between the seal end face forming portion of the rotary seal ring and the stationary seal ring provided in the seal case is relatively rotated to shield and seal the outer peripheral fluid region and the inner peripheral region of the contact portion. Has been
A mechanical seal in which a cooling passage is formed in the main body of the rotary seal ring, from the inlet opening in the outer peripheral surface to the outlet opening in the vicinity of the sealed end face forming portion in the tip end surface.   The mechanical seal according to claim 1, wherein the main body portion of the rotary seal ring is provided with a cylindrical cover body adjacent to a stationary seal ring and surrounding an outer peripheral area of the seal end face forming portion.   The mechanical seal according to claim 1, wherein the seal case is provided with a cylindrical cover body adjacent to the main body of the rotary seal ring and surrounding an outer peripheral area of the seal end face forming portion.   The mechanical seal according to any one of claims 1 to 3, wherein an end of the stationary seal ring faces the outlet of the cooling passage, and an annular recess is formed in an outer peripheral region of the contact portion.

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