JPH073096Y2 - Shaft seal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a mechanical seal and an oil disposed above the rotary shaft of a machine body such as a pump, particularly a rotary shaft vertically inserted into the machine body. The present invention relates to a shaft sealing device that seals a shaft.

[Conventional technology]

Conventionally, in this type of shaft seal device, as shown in FIG. 3, the axial circumference of the rotary shaft 3 vertically inserted through the machine body 1 is
Some have a structure in which a mechanical seal 4 and an oil seal 5 above it are axially sealed. The mechanical seal 4 is fitted to the inner diameter portion 2 of the machine body 1 via an O-ring 42 and the mating ring 41 is fitted to the rotary shaft 3 via the O-ring so as to be movable in the axial direction. A seal ring 46 slidably contacting with the rotary shaft 3, and a spring 45 that supports the collar 43 fixed to the rotating shaft 3 and presses the seal ring 46 toward the mating ring 41 via a spring restraining member 44. The sealant W is circulated and supplied to the lower space 1a. The sealant W or its vaporized gas that has leaked to the space 6 above the mechanical seal 4 is prevented from leaking to the atmosphere by the oil seal 5, and is recovered through the drain hole 7 provided in the machine body 1.

[Problems to be solved by the device]

However, in the conventional shaft seal device described above, when a solvent that corrodes rubber or the like is used as the sealant W, the sealant W leaks into the space 6 and stays in the lower portion thereof.
The vaporized gas may corrode the oil seal 5.

The present invention has been made in view of such a point, and its technical problem is to reliably prevent corrosion of the oil seal due to the sealant leaking from the mechanical seal.

[Means for Solving the Problems]

The above-mentioned conventional technical problems can be effectively solved by the present invention.

That is, the shaft sealing device according to the present invention is a shaft sealing device in which the shaft circumference of a rotary shaft that is vertically inserted through a machine body is sealed by a mechanical seal and an oil seal above it. A baffle sleeve having an upper end fixed to the inner diameter of the machine body and a lower end reaching the inner peripheral space of the sliding surface of the mechanical seal is arranged in the space between the oil seal and the space below the oil seal. From a side to an inner circumference of the baffle sleeve, and an air inlet for sending air to the first passage, and a second passage on the outer circumference of the baffle sleeve for the air bypassing the lower end of the baffle sleeve from the first passage. And an air discharge port for discharging air via the air passage. In this case, a breathable material having a number of continuous fine holes is provided at the lower end of the first passage communicating with the oil seal side. Door is preferable.

[Action]

The air sent from the air inlet opened in the aircraft is
After passing through the first passage on the inner circumference of the baffle sleeve to bypass the lower end of the baffle sleeve reaching the inner circumferential space of the sliding surface of the mechanical seal, and then passing through the second passage on the outer circumference of the baffle sleeve. It is discharged from the air outlet.
Therefore, the sealant and its vaporized gas leaking from the mechanical seal to the space between the oil seal and the upper oil seal and retained in the lower part of this space are generated in the second passage by the air from the first passage side. Since new air is constantly supplied to and intervenes in the first passage that is pushed to the side and communicates with the lower surface of the oil seal, the sealant and its vaporized gas reach the lower surface of the oil seal through the first passage. Never.

In addition, if a breathable material having a large number of continuous fine holes is provided on the lower surface of the first passage, the first breathable material has a function of squeezing air passing through the first passage to the second passage. Since a significant pressure difference is generated between the passage and the second passage, the sealant leaked from the mechanical seal or its vaporized gas is completely blocked from flowing into the first passage side.

〔Example〕

The present invention will be described below with reference to an embodiment shown in FIGS. 1 and 2. In the illustrated embodiment according to the present invention, the same parts as those of the conventional shaft sealing device shown in FIG.

That is, according to the present invention, as shown in FIG. 1, a space portion 6 between the mechanical seal 4 and the oil seal 5 on the upper side thereof is provided.
The upper end is fixed to the inner diameter 2 of the machine body 1, and the lower end 8a is attached to the mating ring 41 and the seal ring 46 of the mechanical seal 4.
A baffle sleeve 8 that reaches the inner peripheral space of the sliding surface 4a is disposed. The baffle sleeve 8 allows the baffle sleeve 8 from the lower end of the oil seal 5 to the space portion 6.
First passage 9 leading to the inner circumference of the baffle sleeve 8
Second passage between the outer periphery of the and the inner periphery of the mechanical seal 4
A detour passage consisting of 10 is formed. The airframe 1 has an air inlet 11 located between the upper end of the baffle sleeve 8 and the oil seal 5 and an air outlet 12 located between the upper end of the baffle sleeve 8 and the mechanical seal 4. There is.

That is, the air A sent from the air inlet 11 into the first passage 9 bypasses the lower end 8a of the baffle sleeve 8 which reaches the inner peripheral space of the sliding surface 4a of the mechanical seal 4,
The air is discharged from the air discharge port 12 through the second passage 10 on the outer circumference of the baffle sleeve 8. Therefore, as shown in FIG. 2, the sealant W circulated in the lower space 1a of the mechanical seal 4 leaks into the space 6 between the mechanical seal 4 and the oil seal 5 and accumulates in the lower part thereof. However, the leaked sealant W is generated by the air A sent into the first passage 9 and the baffle sleeve 8
Of the sealant W to the oil seal 5 side because new air A is constantly supplied to the first passage 9 that is pushed out from the lower end 8a of the sealant W toward the second passage 10 and communicates with the lower surface of the oil seal 5. Is effectively blocked. Further, since the vaporized gas of the leak sealant W is discharged from the air discharge port 12 together with the air A, it does not contact the lower surface of the oil seal 5. Therefore, even if the sealant W is a solvent that corrodes rubber, the oil seal 5 is not corroded.

Further, numeral 13 in the drawing is a first communicating with the oil seal 5 side.
Is a breathable material provided at the lower end of the passage 9 of, and is made of Pola Steflon (Teflon is a trade name) having a large number of continuous fine holes.
A differential pressure is generated between the first passage 9 and the second passage 10 to completely prevent the sealant W leaked from the mechanical seal 4 or its vaporized gas from flowing into the first passage side. It is something like this.

[Effect of device]

As is clear from the above description, according to the present invention, the sealant leaking from the mechanical seal to the space between the upper oil seal and the sealant accumulated under the space is a solvent that corrodes rubber. However, since it is pushed out from the oil seal side by the air that bypasses the lower end of the baffle sleeve and discharged, it is necessary to reliably prevent the leak sealant or its vaporized gas from reaching the bottom surface of the oil seal and corroding the oil seal. You can

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view of an essential part showing an embodiment of a shaft sealing device according to the present invention, and FIG. 2 is an enlarged sectional view of an essential part showing a discharge path of the vaporized sealant. FIG. 3 is a schematic cross-sectional view of a main part of a conventional shaft sealing device. 1 ... Machine body, 2 ... Inner diameter part, 3 ... Rotating shaft, 4 ... Mechanical seal 4a ... Sliding surface, 5 ... Oil seal, 6 ... Space part 8 ... Baffle sleeve, 8a ... Tip, 9 ... First passage 10 ... Second passage, 11 ... Air inlet, 12 ... Air outlet 13 ... Breathable material, A ... Air, W ... Sealant

Claims (2)

[Scope of utility model registration request] 1. A shaft sealing device in which a shaft of a rotary shaft vertically inserted into a machine body is sealed by a mechanical seal and an oil seal above the mechanical seal, and the shaft seal is provided between the mechanical seal and the oil seal. A baffle sleeve, the upper end of which is fixed to the inner diameter of the machine body and the lower end of which reaches the inner peripheral space of the sliding surface of the mechanical seal, is disposed in the space section of the machine body,
An air inlet for sending air to a first passage extending from the lower side of the oil seal to the inner circumference of the baffle sleeve, and the air bypassing the lower end of the baffle sleeve from the first passage to the outer circumference of the baffle sleeve. And an air outlet for discharging the air through the second passage of the shaft sealing device. 2. The shaft sealing device according to claim 1, wherein a breathable material having a large number of continuous fine holes is provided at a lower end portion of the first passage communicating with the oil seal side.