JP4137068B2 - mechanical seal - Google Patents

Description

The present invention relates to a mechanical seal sealed fluid is high-viscosity fluid, relates configured mechanical seal to provide a quench fluid, such as scan team in accordance with the sealing conditions of the properties such as the sealed fluid is there.

  A mechanical seal equipped as a shaft sealing means in a rotary device such as a pump or a mixer is generally a cylindrical seal case attached to a housing of the rotary device, a rotary seal ring fixed to the rotary shaft of the rotary device, A stationary seal ring that is held movably in the axial direction via an O-ring on the inner periphery of the seal case, and a spring retainer and a stationary seal ring provided in the seal case so as to press the stationary seal ring against the rotating seal ring And a sealed fluid region (in-machine region) and an inner peripheral side region, which are outer peripheral side regions of the relative rotational sliding contact portions, by the relative rotational sliding contact action of both sealing rings. (See, for example, Patent Document 1).

  Thus, in such a conventional mechanical seal, it is described in a quench fluid supply passage (for example, FIG. 1 of Patent Document 1 and paragraph number [0031]) opened at one place on the inner peripheral surface of the seal case. A conventional screw 53) is formed, and the non-sealing is secondary sealed between the sealed fluid region by the O-ring according to the sealing conditions such as the properties of the sealed fluid which is the fluid in the in-machine region to be sealed. By supplying quench fluid such as fresh water and steam to the spring area where the spring is arranged, which is the fluid region, the ambient temperature of the seal part (the relative rotational sliding contact part of both seal rings) is controlled. Things have been done.

For example, when the fluid to be sealed is a high-viscosity fluid, the high-viscosity fluid that has entered the O-ring loading portion, which is the secondary seal portion between the seal case and the stationary seal ring, solidifies and follows the stationary seal ring. However, in such a case, by supplying a high-temperature fluid such as steam as a quench fluid to the spring installation space, the ambient atmosphere temperature of the seal portion is maintained at a certain level or higher, The high-viscosity fluid is prevented from solidifying and the high-viscosity fluid leaking from the seal portion to the non-sealed fluid region is washed away by the quench fluid to prevent the high-viscosity fluid from solidifying and depositing on the seal portion .

JP2003-314703

However, only to supply the quench fluid from quench fluid supply passage between the spring disposing space, heating effect due to the quench fluid is insufficient, it is impossible to properly manage the ambient atmosphere temperature of the seal portion, a high viscosity there is a problem it is impossible to prevent caking phenomenon of the fluid effectively.

  The present invention provides a mechanical seal that does not cause such problems, can exhibit a good quenching function, and can manage the ambient temperature around the seal portion to an appropriate temperature according to the seal conditions. It is intended.

The present invention includes a cylindrical seal case attached to a housing of a rotary device such as a pump and a mixer, a rotary seal ring fixed to the rotary shaft of the rotary device, and an O-ring on the inner peripheral portion of the seal case. A stationary seal ring held movably in the axial direction, a spring loaded between a spring retainer provided in the seal case and the stationary seal ring to press the stationary seal ring against the rotary seal ring, and the O In order to supply a quench fluid as a high-temperature fluid to a non-sealed fluid region portion that is secondarily sealed between a sealed fluid region that is a high-viscosity fluid region by a ring and in which the spring is disposed In order to achieve the above object, in particular, the quench fluid supply passage is sealed in a mechanical seal including a quench fluid supply passage formed in the seal case. A quench fluid chamber extending along at least the position of the O-ring in the axial direction from the position where the O-ring is disposed to the position where the two seal rings are in contact or the vicinity thereof, and the quench fluid into the quench fluid chamber. It is proposed to comprise a quench fluid supply passage to be supplied and a quench fluid ejection passage for ejecting the quench fluid from the quench fluid chamber to the spring arrangement space. By configuring the intermediate portion of the quench fluid supply path in the quench fluid chamber described above, heat exchange between the quench fluid in the quench fluid chamber and the sealed fluid that is a high-viscosity fluid and the seal ring around the seal portion is effective. As compared with the case where only the quench fluid is supplied to the spring installation space, the ambient temperature around the seal portion by the quench fluid can be managed at an appropriate temperature according to the seal condition.

  Thus, in such a mechanical seal, a plurality of quench fluid ejection passages are radially formed so as to open at equal intervals in the circumferential direction on the inner peripheral surface portion of the seal case facing the spring installation space. It is preferable to provide it. That is, in this way, unlike the conventional mechanical seal, unlike the case where the quench fluid is supplied from the opening provided at one place on the inner peripheral surface of the seal case to the spring installation space, the spring Since the quench fluid is supplied (spouted) from the entire circumference of the arrangement space, that is, the quench fluid is showered in the spring arrangement space, the quench fluid is coupled with the presence of the quench fluid chamber described above. The temperature management by is performed more effectively.

  Further, a secondary seal member that seals between the seal case and the rotary shaft on the back side of the spring retainer is provided between the opposed peripheral surfaces of the seal case and the rotary shaft, and the secondary seal member and the spring are provided on the seal case. A quench fluid discharge passage communicating with the quench fluid discharge space formed between the retainer and the inner periphery of the spring retainer is formed between the opposed peripheral surfaces of the stationary seal ring and the rotary shaft, and both are sealed. A first baffle and a baffle formed by projecting a cylindrical baffle extending to a contact position of the ring or a position in the vicinity thereof so that quench fluid supplied to the spring installation space is formed between the baffle and the stationary seal ring It is preferable that the second flow passage formed between the rotary shaft and the rotating shaft sequentially flow and be discharged from the quench fluid discharge space to the quench fluid discharge passage. Arbitrariness.

According to the mechanical seal of the present invention, by providing the quench fluid chamber as described above the intermediate portion of the quench fluid supply passage formed in the seal case, it can not be provided a jacket for heating the housing of the rotating device Even in this case, the heat transfer efficiency by the quench fluid can be improved, and the temperature management of the seal portion and the surrounding atmosphere can be effectively performed. Further, the downstream portion of the quench fluid supply passage is constituted by a plurality of quench fluid ejection passages so that the quench fluid is showered in the spring installation space, and further between the stationary seal ring and the rotating shaft. By providing the first and second flow passages as described above, such temperature management can be performed more effectively.

  FIG. 1 is a longitudinal side view showing an example of a mechanical seal according to the present invention, FIG. 2 is an enlarged view of an essential part thereof, and FIG. 3 is a longitudinal front view taken along line III-III in FIG. In the following description, front and rear mean the left and right in FIG. 1 or FIG.

The mechanical seal shown in FIG. 1 includes a cylindrical seal case 2 attached to a housing 1 of a rotary device (pump, mixer, etc.), a rotary seal ring 4 fixed to a rotary shaft 3 of the rotary device, and a seal case 2. A stationary seal ring 6 held on the inner peripheral portion of the stationary seal ring 6 so as to be movable in the axial direction (front-rear direction) via an O-ring 5, and a stationary seal ring 6 to press the stationary seal ring 6 against the rotary seal ring 4. Between the seal case 2 and the rotary shaft 3, the spring 8 loaded between the spring retainer 7 provided in the seal case 2, the quench fluid supply path 9 and the quench fluid discharge path 10 formed in the seal case 2. And a quench fluid flow path 11 formed on the sealing ring surfaces 4a and 6a. The relative rotational sliding contact portions (seal portions) 4a, 6 To shield seal and B (outside the region of the rotating device) unsealed fluid region including A and inner circumferential side area (inboard region of the rotating device) the sealed fluid region that is a high-viscosity fluid region including the outer peripheral side region of the It is the end surface contact type mechanical seal comprised in this.

  As shown in FIG. 1, the seal case 2 is made of metal having a cylindrical structure in which the rotation shaft 3 is concentrically penetrated, and includes a cylindrical main body portion 12 attached to the rear end portion of the housing 1, and a main body. An appropriate number of cylindrical protrusions 13 projecting from the front end of the portion 12 and fitted to the inner peripheral portion of the rear end of the housing 1 together with the main body 12 in a state of abutting the rear end of the main body 12 And a cylindrical seal portion 15 attached to the housing 1 by bolts and nuts 14.

  As shown in FIG. 1, the rotary seal ring 4 has a sleeve 16 and a seal ring retainer on the rotary shaft 3 in a state where the seal end surface 4a as the rear end surface is located at a position corresponding to the front end portion of the protrusion 13 of the seal case 2. 17 is fixed. The sleeve 16 has a long cylindrical shape extending from the inside of the housing 1 to the outside of the seal case 2, and is inserted and fixed to the rotary shaft 3 through a fixed ring 18. The fixing ring 18 fixes the sleeve 16 to the rotating shaft 3 by fitting and fixing the rotating shaft 3 and the rear end portion of the sleeve 16 with screws 19 and 20 outside the seal case 2. The seal ring retainer 17 has a cylindrical shape whose front end is fitted and fixed to the front end of the sleeve 16, and the rotary seal ring 4 is fitted to the rear end via an O-ring 21 and a drive pin 22 so as not to be relatively rotatable. It is fixed.

  As shown in FIGS. 1 and 2, the stationary sealing ring 6 is opposed to the sealing end surface 4 a that is the rear end surface of the rotary sealing ring 4, and the axial direction (front-rear direction) via an O-ring 5 on the inner peripheral portion of the sealing case 2. ) Is movably fitted and held. The stationary sealing ring 6 includes a sealing ring main body 23 having a front end surface (front end surface) formed as a sealing end surface 6a which is a narrow annular surface, a cylindrical holding body 24 that fits and fixes the sealing ring main body 23 to the front end, An annular spring receiving body 26 is fitted to the rear end portion of the holding body 24 via a drive pin 25 so as not to be relatively rotatable, and the opposite periphery of the intermediate portion of the holding body 24 and the main body portion 12 of the seal case 2 By loading the O-ring 5 between the surfaces, the seal case 2 (main body portion 12) is held so as to be movable in the axial direction in a state of being secondarily sealed with the seal case 2. The O-ring 5 is engaged and held in an O-ring groove 12a formed in the inner peripheral portion of the main body 12 of the seal case 2. The stationary sealing ring 6 is allowed to move in the axial direction within a predetermined range by engaging a drive pin 27 projecting from the spring receiver 26 with an engagement hole 28 formed in the spring retainer 7 described later. In this state, relative rotation with respect to the seal case 2 is prevented.

  As shown in FIGS. 1 and 2, the spring retainer 7 is an annular body, and is in a state facing the rear end surface of the spring receiver 26 and a locking step portion 29 formed at the front end portion of the seal portion 15 of the seal case 2. In the abutted state, it is fitted and held in the main body 12 of the seal case 2 and is prevented from rotating relative to the seal case 2 by a drive pin 30 interposed between the locking step 29.

  As shown in FIGS. 1 and 2, the spring 8 is interposed between the spring receiver 27 of the stationary seal ring 6 and the spring retainer 7, and presses the stationary seal ring 6 against the rotary seal ring 4. is doing.

As shown in FIG. 1, the quench fluid supply path 9 is composed of a quench fluid chamber 31, a quench fluid supply passage 32, and a plurality of quench fluid ejection passages 33. A quench fluid 34, which is a high-temperature fluid such as steam, is supplied to the spring-sealed space B1 in which the spring 8 is disposed, which is the next sealed non-sealed fluid region B portion.

The quench fluid chamber 31 is an annular space along the inner peripheral surface of the seal case 2 as shown in FIGS. 1 and 2, and at least the position where the O-ring 5 is disposed in the axial direction (front-rear direction) (in this example, It extends from the position corresponding to the front end of the spring receiver 26) to the contact position of the sealing rings 4 and 6 or to a position in the vicinity thereof (in this example, the position in the vicinity of the rear of the seal portions 4a and 6a). The front surface of the quench fluid chamber 31 is closed at the rear end of the equipment housing 1. Further, the front end portion of the quench fluid chamber 31 is formed between the protruding portion 13 of the seal case 2 and the inner peripheral portion 35 of the device housing 1, and is provided by an O-ring 36 interposed between the both portions 13 and 35. It is sealed. In the quench fluid chamber 31, heat exchange between the quench fluid 34 supplied from the quench fluid supply passage 32 (described later) and the sealed fluids that are the high-viscosity fluids in both the sealing rings 4 and 6 is performed well. It has a sufficient volume.

  As shown in FIG. 1, the quench fluid supply passage 32 is formed in the main body portion 12 of the seal case 1 and extends from the outer peripheral portion of the main body portion 12 to the quench fluid chamber 31, and the quench fluid 34 is transferred to the quench fluid chamber. 31.

  As shown in FIGS. 1 to 3, each of the plurality of quench fluid ejection passages 33 has a narrow cross-section nozzle shape extending radially from the quench fluid chamber 31 toward the inner circumferential direction of the seal case 1. The seal case 1 (main body portion 12) facing the spring arrangement space B1 is opened at equal intervals in the circumferential direction on the inner peripheral surface portion. Therefore, the quench fluid 34 supplied to the quench fluid chamber 31 is ejected from the entire circumference of the plurality of quench fluid ejection passages 33..., That is, showered.

  As shown in FIGS. 1 and 2, the quench fluid discharge passage 10 has a main body of the seal case 2 so as to open to a quench fluid discharge space B2 which is an unsealed fluid region B portion on the back side (rear side) of the spring retainer 7. It is formed in the part 12. Between the opposed peripheral surfaces of the seal case 1 and the rotary shaft 2, a seal member 37 for secondary sealing between the seal case 1 and the rotary shaft 2 is provided on the back side (rear side) of the spring retainer 7. A quench fluid discharge space B <b> 2 is formed between the seal member 37 and the spring retainer 7. In this example, a segment seal is used as the seal member 37. As shown in FIG. 1, the segment seal 37 is composed of a pair of front and rear seal rings 38, 38 formed by binding a plurality of arc-shaped segments in a ring shape contacting the rotary shaft 3 with a garter spring 39. The seal ring 38 is loaded into an annular recess 40 formed in the inner peripheral portion of the main body 12 of the seal case 1, whereby the seal case 1 and the rotary shaft 3 are secondarily sealed.

  As shown in FIGS. 1 and 2, the quench fluid flow path 11 communicates the spring disposition space B 1 and the quench fluid discharge space B 2, and is formed between the opposed peripheral surfaces of the stationary seal ring 6 and the rotating shaft 3. This is a meandering passage composed of the first and second flow passages 11a and 11b. That is, a cylindrical baffle 41 that passes between the opposed peripheral surfaces of the stationary seal ring 6 and the rotary shaft 3 and extends to a contact position of the seal rings 4 and 6 or a position in the vicinity thereof is provided on the inner peripheral portion of the spring retainer 7. A first flow passage 11 a that protrudes integrally and communicates with the spring disposition space B 1 is formed between the baffle 41 and the stationary sealing ring 6, and the first flow passage 11 a is formed between the baffle 41 and the rotary shaft 3. A second flow passage 11b that communicates the flow passage 11a and the quench fluid discharge space B2 is formed.

  In the mechanical seal configured as described above, the quench fluid 34 is supplied from the quench fluid supply passage 32 to the quench fluid chamber 31, and is further ejected from the quench fluid ejection passage 33. Therefore, heat exchange between the quench fluid 34 temporarily staying in the quench fluid chamber 31 and the sealed fluid around the seal portions 4a and 6a and the seal rings 4 and 6 is effectively performed. In addition, the quench fluid 34 is ejected from the plurality of quench fluid ejection passages 33 to the spring arrangement space B1 over the entire circumference, that is, the quench fluid 34 is showered. In this way, quenching by the quench fluid 34 is more effectively performed than when the quench fluid is supplied from one place to the spring arrangement space.

  Further, the quench fluid 34 ejected into the spring disposition space B1 flows from the first flow passage 11a to the seal portions 4a and 6a along the inner peripheral surface of the stationary seal ring 6, and around the seal portions 4a and 6a. It reverses in the region, flows from the second flow passage 11b to the quench fluid discharge space B2, and is discharged from the quench fluid discharge passage 10. Accordingly, heat exchange between the stationary fluid ring 6 and the stationary seal ring 6 is favorably performed by the quench fluid 34 that passes through the first flow passage 11a, and the quench fluid 34 that reversely flows from the first flow passage 11a to the second flow passage 11b. Heat exchange or cleaning between this and the seal portions 4a and 6a is effectively performed.

For these reasons, the heating effect by the quench fluid 34 (when using a high-temperature fluid such as steam as the quench fluid 34 ) is satisfactorily exhibited, and the seal portions 4a and 6a and the ambient ambient temperature can be appropriately managed. , it is possible to effectively prevent caking phenomenon of high viscosity fluids. Therefore, a good mechanical seal function can be exhibited over a long period of time.

It is a vertical side view which shows an example of the mechanical seal which concerns on this invention. It is an enlarged view of the principal part of FIG. It is a longitudinal front view which follows the III-III line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing of rotating equipment 2 Seal case 3 Rotating shaft 4 Rotating sealing ring 4a Sealing end face of rotating sealing ring 5 O-ring 6 Static sealing ring 6a Sealing end face of stationary sealing ring 7 Spring retainer 8 Spring 9 Quench fluid supply path 10 Quench fluid discharge 10 Path 11 Quench fluid flow path 11a First flow path 11b Second flow path 31 Quench fluid chamber 32 Quench fluid supply path 33 Quench fluid ejection path 34 Quench fluid 37 Seal member (segment seal)
41 Baffle A Sealed fluid region B Non-sealed fluid region B1 Spring installation space B2 Quench fluid discharge space

Claims (1)

A cylindrical seal case (2) attached to the housing (1) of the rotary device, a rotary seal ring (4) fixed to the rotary shaft (3) of the rotary device, and an inner peripheral portion of the seal case (2) A stationary seal ring (6) held axially through an O-ring (5) and a sealing case (2 ) for pressing the stationary seal ring (6) against the rotary seal ring (4) . ) and spring retainer (7) provided on the spring (8) loaded between the stationary seal ring (6), is a high-viscosity fluid region by the O-ring (5) and the sealed fluid region (a) A non-sealed fluid region (B) that is secondarily sealed between the two and sealed to supply a quench fluid (34) that is a high-temperature fluid to a spring disposition space (B1) in which the spring (8) is disposed. quench fluid supply passage formed in the case (2) ( ) And, in the mechanical seal comprising a
Quench fluid supply channel (9), an annular space along the inner circumferential surface of the seal case (2), at least the installation position of the O-ring (5) in the axial direction of both seal rings (4,6) A quench fluid chamber (31) extending to the contact position or a position in the vicinity thereof, a quench fluid supply passage (32) for supplying the quench fluid (34) to the quench fluid chamber (31) , and a quench fluid (34) for the quench fluid chamber ( between spring disposing space from 31) and (plurality of quench fluid ejection passage for ejecting the B1) (33), Ri Tona,
The plurality of quench fluid ejection passages (33) are provided radially on the inner peripheral surface portion of the seal case (2) facing the spring installation space (B1) so as to open at equal intervals in the circumferential direction. And
Secondary seal for secondary sealing between the seal case (2) and the rotating shaft (3) between the opposing peripheral surfaces of the seal case (2) and the rotating shaft (3) on the back side of the spring retainer (7). In addition to providing the member (37), the quenching fluid discharge space (the non-sealed fluid region (B) portion formed between the secondary seal member (37) and the spring retainer (7) in the seal case (2) ( B2) is formed in the quench fluid discharge passage (10), and the inner periphery of the spring retainer (7) passes between the opposed peripheral surfaces of the stationary seal ring (6) and the rotating shaft (3). A cylindrical baffle (41) extending to the contact position of both seal rings (4, 6) or the vicinity thereof is projected, and the quench fluid (34) supplied to the spring arrangement space (B1) is baffled ( 41) and stationary sealing ring (6) The first fluid passage (11a) and the second fluid passage (11b) formed between the baffle (41) and the rotating shaft (3) sequentially flow to the quench fluid discharge space (B2) to the quench fluid discharge passage. (10) The mechanical seal characterized by being discharged to (10) .