JP7372831B2 - mechanical seal - Google Patents

Description

The present invention relates to a mechanical seal, and particularly to a cartridge-type mechanical seal that can be extremely easily installed in and removed from a rotating device.

In conventional cartridge-type mechanical seals, as disclosed in Patent Document 1, there is a stationary side sealing element consisting of a seal case and a stationary sealing ring attached thereto, and a rotating side sealing element consisting of a sleeve and a rotating sealing ring attached thereto. It consists of a side sealing element and a connecting means for temporarily connecting both sealing elements in the same form as the usage form, and is installed in a rotating equipment while both sealing elements are connected in the same form as the usage form by the connecting means. It is designed to be removed from rotating equipment.

Japanese Patent Application Publication No. 2005-048818

However, because the seal case is directly attached to the shaft seal casing of rotating equipment, even if the shaft diameters of the rotating shafts are the same, if the model or manufacturer is different, the seal case cannot be attached to the shaft seal casing. A situation occurs. Therefore, even if the sealing elements are prepared in a state in which they are connected in the same manner as in use by the connecting means, it is difficult to apply the sealing element to all rotating devices having the same shaft diameter.

That is, even if a cartridge-type mechanical seal is prepared that is easy to incorporate into and remove from a rotating device, it is necessary to replace the seal case. In this case, reassembly is required, and there is a risk that assembly errors may occur each time.

The present invention has been made in view of these points, and an object of the present invention is to provide a mechanical seal that can be applied to rotating equipment having the same rotating shaft diameter even if the model or manufacturer is different.

A mechanical seal that has solved this problem has a seal case that has an annular first case part and a cylindrical second case part that extends concentrically from the first case part and has a smaller diameter than the first case part. and a mounting plate having a through hole that fits into the second case part, the mounting plate fits the through hole into the second case part, and the first case part is connected to the shaft of the rotating device. It is attached to the shaft seal casing in a state where it comes into contact with the end face of the seal casing.

In a preferred embodiment of such a mechanical seal, an O-ring is interposed between the first case portion and the shaft seal portion casing. Further, an engagement bolt for preventing rotation of the stationary sealing ring is fitted into the second case part with its head positioned above the second case part, and is inserted into the through hole of the mounting plate. A notch is formed in which the head of the engagement bolt is engaged.

The mechanical seal according to the present invention can be applied to rotating equipment having the same rotating shaft diameter by simply replacing the mounting plate, even if the model or manufacturer is different.

1 is a sectional view showing an example of a mechanical seal according to the present invention. FIG. 3 is a sectional view of the mechanical seal showing a different cross section from FIG. 1 (the cross section is taken along line II-II in FIG. 3). 2 is a sectional view taken along line III-III in FIG. 1. FIG. FIG. 2 is a sectional view corresponding to FIG. 1 showing a state in which the mechanical seal is installed in a rotating device. FIG. 2 is a sectional view corresponding to FIG. 1 showing a modification of the mechanical seal according to the present invention. 5 is a sectional view corresponding to FIG. 2 of the mechanical seal, showing a different cross section from FIG. 5. FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A mode for carrying out the present invention will be specifically described based on the drawings.

As shown in FIGS. 1 and 2, a cartridge-type mechanical seal, which is an example of a mechanical seal, connects to a shaft seal casing 1 of a rotating device (process pump, blower, compressor, turbine, stirrer, etc.) and penetrates this. and the rotary shaft 2 that protrudes outside the device. The mechanical seal is of an end face contact type configured to partition between an in-machine fluid region A, which is an internal region of a rotating device, and an external atmospheric region B, which is an external region of the rotating device.

This cartridge type mechanical seal includes a rotating side sealing element 3 attached to a rotating shaft 2, a stationary side sealing element 5 attached to a shaft seal casing 1 by a mounting plate 4, and both sealing elements 3 and 5 of the mechanical seal. It is provided with a connecting means 6 for temporarily connecting it in the same configuration as the usage configuration (the configuration in the operating state shown in FIGS. 1 and 2). In this example, the fluid in the in-machine fluid region A (sealed fluid) is a positive pressure fluid.

As shown in FIGS. 1 and 2, the shaft seal casing 1 has a circular through hole 1a, and a rotating shaft 2 passes through the through hole 1a concentrically. From the shaft seal casing 1, bolts (two bolts) 7, 7 protrude parallel to the rotating shaft 2 from the end surface 1b on the side of the external atmospheric region B. The bolts 7, 7 are provided symmetrically with the through hole 1a in between.

As shown in FIGS. 1 and 2, the rotation-side sealing element 3 includes a sleeve 8 fitted onto the rotation shaft 2, a rotation seal ring 9 attached to the sleeve 8, a stopper ring 10, and the like.

The sleeve 8 is attached to the rotating shaft 2 with a thin-walled cylindrical base end 81 located on the outside atmospheric region B side and a thick-walled cylindrical tip end 82 located in the through hole 1a of the shaft seal casing 1. is mated to. The sleeve 8 is formed at the base end 81 of the sleeve 8 by screwing a plurality of first screws 10a (only one is shown) that are tightened into the sleeve 8 into a stopper ring 10 fitted to the base end 81. It is fixed to the rotating shaft 2 by screwing together a plurality of second screws 10b (only one is shown) that are tightened to the rotating shaft 2 through the through hole 83.

The rotary sealing ring 9 is fitted into the tip 82 of the sleeve 8, and is fixed to the tip 82 of the sleeve 8 via an O-ring 11a, a drive pin 11b, and a sheet material 11c.

As shown in FIGS. 1 and 2, the stationary side sealing element 5 includes a seal case 13, a stationary seal ring 14 held by the seal case 13, a spring 15, and the like.

The seal case 13 includes a first case part 131 in the shape of an annular plate having the largest diameter in the stationary side sealing element 5, and a second large case part 131 that extends concentrically from the middle part of the first case part 131 in the direction of the external atmospheric region B. The second case part 132 has a cylindrical shape and has a diameter of about 100 mm. A spring retainer 133 is fitted into the inner peripheral portion of the second case portion 132 in the seal case 13 .

The end surface of the first case portion 131 is an annular surface 131a that can be brought into close contact with the end surface 1b of the shaft seal casing 1, and an O-ring 16 is mounted on this annular surface 131a. The second case part 132 is integrally molded with the first case part 131. The outer diameter of the second case part 132 is the second largest diameter and is smaller than the outer diameter of the first case part 131, but it is smaller than the outer diameter of the other members constituting the seal case 13 and the spring retainer 133. It is large in comparison.

The O-ring holding part 134 extends along the inner peripheral surface of the first case part 131 and has a smaller diameter than the inner diameter of the second case part 132. The O-ring holding part 134 is formed integrally with the first case part 131, and includes a receiving surface 134a that slightly protrudes from the annular surface 131a of the first case part 131, and a movement prevention surface 134b extending inward from the base end thereof. has been done. The receiving surface 134a is in contact with the through hole 1a of the shaft seal casing 1. An annular convex portion 133a is integrally formed at an end of the spring retainer 133, which is located a little apart from the stopper ring 10.

The stationary sealing ring 14 includes a sealing ring holder 141 whose tip end (end on the in-machine fluid region A side) has a large diameter, and a sealing ring main body 142 attached to the tip of the sealing ring holder 141.

An intermediate portion of the seal ring holder 141 is held by an O-ring holding portion 134 of the seal case 13 via an O-ring 17 so as to be movable in the axial direction. A notch 141a is formed at the base end of the sealing ring holder 141. The engagement bolt 18 passes through the first case body 131 in the radial direction and is screwed into the second case body 132 through the notch 141a. The base end pin portion 181 of the engagement bolt 18 prevents relative rotation of the stationary seal ring 14 with respect to the seal case 13 by screwing into the notch portion 141a. The head (tip) 182 of the engagement bolt 18 is tightened in contact with the outer circumferential surface of the second case portion 132 . That is, the head 182 of the engagement bolt 18 protrudes radially outward from the outer peripheral surface of the second case portion 132.

The spring 15 is loaded between a spring retainer 133 and a spring receiving plate 19 held by a seal ring holder 141, and is axially moved in order to bring the seal ring main body 142 of the stationary seal ring 14 into contact with the rotating seal ring 9. is affiliated with. The spring receiving plate 19 is located at a step formed on the sealing ring holder 141 and is locked by the biasing force of the spring 15.

As shown in FIGS. 2 and 3, the connecting means 6 connects both sealing elements 3 and 5 in the same state as in use during storage, transportation, and installation of rotating equipment.

That is, the connecting means 6 includes an engaging body 61 having a concave portion that engages with an annular convex portion 133a formed on the spring retainer 133 and a convex portion that engages in the gap between the spring retainer 133 and the stopper ring 10; A bolt 62 is fixed to the stopper ring 10 from above. The connecting means 6 connects the stopper ring 10 and the spring retainer 133 (seal case 13).
Further, as shown in FIG. 3, the connecting means 6 are provided at three locations equally spaced in the circumferential direction.

The head 62a of the bolt 62 attached to the stopper ring 10 is set to be slightly higher than the outer diameter of the second case portion 132 of the seal case 13. Further, the outer diameter of the stopper ring 10 is smaller than the inner diameter of the second case part 132 of the seal case 13, and the head 62a of the bolt 62 is set smaller than the outer diameter of the first case part 131 of the seal case 13.

As shown in FIGS. 1 and 2, in the cartridge type mechanical seal, the seal case 13 of the stationary side sealing element 5 is attached to the shaft seal part casing 1 by the mounting plate 4.

The mounting plate 4 has a plate shape with a circular through hole 41 formed in the center, and a long hole 42 for passing the bolt 7 through each end. The through hole 41 is formed to match the outer diameter of the second case portion 132 of the seal case 13, and is set to a diameter that allows it to fit into the second case portion 132. Notches 43 and 44 are formed in the through hole 41 of the mounting plate 4. The notches 43 and 44 are the head 182 of the engagement bolt 18 that protrudes from the outer periphery of the second case portion 132 of the seal case 13, and each bolt of the connecting means 6 that protrudes from the outer periphery of the second case portion 132. 62 heads 62a pass through.

Therefore, according to the mounting plate 4, both sealing elements 3 and 5 are taken out from storage in a state connected by the connecting means 6, transported to the rotating equipment, and inserted into the rotating shaft 2 of the rotating equipment as shown in FIG. By doing so, it can be attached to the shaft seal casing 1 of a rotating device.

That is, as shown in FIG. 4, both sealing elements 3 and 5 are inserted into the rotating shaft 2. At this time, the second screw 10b of the stopper ring 10 is not tightened onto the rotating shaft 2, so that both sealing elements 3 and 5 can be easily inserted into the rotating shaft 2. At this time, an annular collar 21 corresponding to the thickness of the first case portion 131 of the seal case 13 is passed through each bolt 7. Then, the annular surface 131a of the first case portion 131 of the seal case 13 is brought into contact with the end surface 1b of the shaft seal portion casing 1. Then, the through hole 41 is inserted into the second case portion 132 of the seal case 13 with the O-ring 16 interposed between the end surface 1b and the annular surface 131a. Thereafter, the bolts 7 are inserted into each elongated hole 42, and the nuts 20 are screwed onto each bolt 7. As shown in FIGS. 1 and 2, by tightening each nut 20, the mounting plate 4 is fixed to the shaft seal casing 1 while being pressed against the first case portion 131. Further, the mounting plate 4 allows the notch 43 to engage the head 182 of the engagement bolt 18 by passing the head 62a of each bolt 62 of the connecting means 6 through the notch 44 and then rotating it by a predetermined angle. .

After the seal case 13 is attached to the shaft seal casing 1 by the attachment plate 4, the second screw 10b of the stopper ring 10 is finally tightened to fix the stopper ring 10 to the rotating shaft 2. At this time, the head 182 of the engagement bolt 8 is caught in the notch 42 of the mounting plate 4. Thereby, the stationary side sealing element 5 prevents relative rotation of the rotating equipment with respect to the shaft seal part casing 1.

In this way, according to the mounting plate 4, both sealing elements 3 and 5 remain connected by the connecting means 6 in the same state as in use, and the shaft sealing part casing 1 is moved through management, transportation, and insertion into the rotating shaft 2. Therefore, there is no need to change both the sealing elements 3 and 5 including the seal case 13.

Therefore, as long as the shaft diameter of the rotating shaft 2 is the same, even if the model or manufacturer is different, it can be used with any rotating equipment simply by changing the shape of the mounting plate 4 to fit the shaft seal casing 1. . Moreover, since there is no need to change the seal case 13, even if the model or manufacturer is different, as long as the shaft diameter of the rotating shaft 2 is the same, there is no need to change both sealing elements 3 and 5, and the seal case No assembly errors occur due to disassembly and reassembly due to changes in item 13.

FIGS. 5 and 6 show modified examples of the mechanical seal. As shown in FIG. 5, the mechanical seal of this modification is attached to the shaft seal part casing 1 not by a threaded bolt 7 but by a bolt 70 of a type that is screwed into the shaft seal case, such as a bolt with a socket or a hexagonal bolt. . Further, the collar 21 does not necessarily need to be provided. Note that the components other than the bolts 70 are the same as those shown in FIGS. 1 to 4, so the same reference numerals are given and explanations are omitted.

Furthermore, as shown in FIGS. 5 and 6, even if the through hole 1a of the shaft seal part casing 1 is large and the receiving surface 134a of the seal case 13 does not come into contact with the through hole 1a, there is no problem in terms of the sealing function. Does not occur.

Furthermore, as shown in FIG. 6, when the head 182 of the engagement bolt 18 does not protrude above the upper surface of the second case part 132 of the seal case 13 and is buried in the second case part 132, the attachment part 4 Relative rotation of the seal case 13 with respect to the shaft seal part casing 1 is prevented by the frictional engagement force between the first case part 131 and the second case part 132 of the seal case 13.

In this way, in the mechanical seal of the present invention, by preparing various mounting plates 4, when the shaft diameter of the rotating shaft 2 is the same, both sealing elements 3 and 5 can be used without changing. It can be applied to all rotating equipment of different models and manufacturers.

1 Shaft seal casing 4 Mounting plate 13 Seal case 14 Stationary seal ring 16 O-ring 18 Engagement bolt 41 Through hole 43 Notch 131 First case part 132 Second case part 182 Head

Claims (2)

a seal case having an annular first case part and a cylindrical second case part extending concentrically from the first case part and having a smaller diameter than the first case part;
a mounting plate having a through hole that fits into the second case part;
The mounting plate is attached to the shaft seal casing of the rotating device in a state where the through hole is fitted into the second case portion and the first case portion is in contact with an end surface of the shaft seal casing of the rotating device ;
An engagement bolt that prevents rotation of the stationary sealing ring is inserted into the second case part with its head positioned above the second case part, and the corresponding bolt is inserted into the through hole of the mounting plate. A mechanical seal that has a notch that locks the head of the engagement bolt . The mechanical seal according to claim 1, wherein an O-ring is interposed between the first case portion and the shaft seal portion casing.

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