JPH0448376Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mechanical seal for sealing the rotating shaft portion of a machine body.

[Prior Art] Conventionally, as an example of this type of mechanical seal, as shown in FIG.
A seal ring 5, which is a rotary sliding ring supported by a retainer 4, is disposed, while a mating ring 6, which is a fixed sliding ring, is fixed to the housing 1 side of the machine body via an O-ring 7. The seal ring 5 is assembled to the mating ring 6 so as to be in sliding contact with the mating ring 6, and the seal ring 5 is backed up by a spring 9 through the collar 8 to bias it in the axial direction. While pressing the ring 6 side, sealing fluid W is injected into the space of the shaft sealing part between the seal ring 5 and the mating ring 6 from the flushing/cooling hole 10 provided in the housing 1 of the machine body, thereby, A device having a configuration for performing flushing is known.

[Problems to be solved by the invention] However, in such a conventional mechanical seal, the shaft sealing portion between the seal ring 5 and the mating ring 6 is removed from the flushing cooling hole 10 provided in the housing 1 of the machine body. By injecting sealing fluid W into the space, flushing is performed to control the heat generated by sliding of the shaft seal, so the heat transfer coefficient at that time is only 1000Kcal/m ² H・
As a result, the sliding surface becomes insufficiently cooled, causing cracks and blisters to occur on the sliding surface, making it easy to fail, which not only reduces sealing performance, but also withstands high P/V values. I had a problem that I couldn't do.

[Purpose of the invention] The present invention was made under the above circumstances, and its purpose is to reliably prevent failures due to heat on the sliding surface of the shaft seal, and improve sealing performance and durability. To provide a mechanical seal with improved performance.

[Means for solving the problems] In order to solve the above problems, the present invention has the following features:
A mechanical seal in which a fixed sliding ring is in sliding contact with a rotating sliding ring includes an evaporation space within the fixed sliding ring that reaches near the sliding surface and is led out to the outside, and an evaporation space inserted into the evaporation space. The structure includes a required number of coolant injection nozzles that open facing the sliding surface side end surface of the space.

[Function] That is, the present invention has the above-described configuration, so that the coolant injected from the coolant injection nozzle to the end face on the sliding surface side of the evaporation space inside the fixed sliding ring can be applied to both sliding contacts. The sliding heat generated on the sliding surface of the ring is consumed and evaporated as vaporization heat, and this sliding heat is released to the outside in the form of latent heat, so compared to the case where heat exchange is performed with the temperature of the cooling fluid itself. The cooling efficiency is extremely high, so failures due to heat on the sliding surface of the shaft seal can be reliably prevented, thereby improving sealing performance and durability.

[Example] The present invention will be described below with reference to an example shown in FIGS. 1 and 2. In the illustrated embodiment of the present invention, parts having the same structure as the conventional mechanical seal shown in FIG. 3 will be described using the same reference numerals.

In other words, the mechanical seal according to the present invention is
As shown in FIGS. 1 and 2, the mating ring 6 as a stationary sliding ring has an evaporation groove or hole that reaches near the sliding surface A of the sealing ring 5 as a rotating sliding ring. A space 61 is formed, and the coolant injection nozzle 21 is inserted into this evaporation space 61, and its tip 21a is opened facing the end face 61a of the evaporation space 61 located near the sliding surface A. The cooling liquid W, such as water or alcohol, is injected from the injection nozzle 21 onto the end surface 61a. The evaporation space 61 is connected to the coolant injection nozzle 2 via an external condensation section (not shown).
1 to constitute a coolant circulation supply mechanism 20.

According to the above configuration, the end surface 61 of the evaporation space 61
The coolant W that is injected and supplied to a immediately evaporates as the heat of sliding from the sliding surface A becomes heat of vaporization. In particular, in the case of a coolant W with a low boiling point such as alcohol, it evaporates actively with a boiling phenomenon. The steam transfers the sliding heat in the form of latent heat, is compressed in an external condensing section, radiates heat, liquefies, and returns to the coolant injection nozzle 21 again. This increases the heat transfer coefficient to 20000Kcal/
m ² H·C, greatly improving cooling efficiency and making it possible to sufficiently withstand high P·V values.

Note that the present invention is not limited to the above-described embodiments, and the depth and shape of the evaporation space 61 of the groove or hole formed in the mating ring 6, or the diameter, shape, and number of the coolant injection nozzles 21 may vary. Furthermore, the type of cooling liquid W, etc. are appropriately set according to the required cooling capacity.

In addition, it goes without saying that the present invention can be modified in various ways without departing from the gist of the invention.

[Effect of the invention] As is clear from the above explanation, according to the invention, the cooling liquid is evaporated at the end face on the sliding surface side of the evaporation space provided in the fixed sliding ring, and the heat of sliding is transferred to the cooling liquid. Since the heat of vaporization during evaporation is transferred to the outside and released, the temperature near the sliding surface does not rise above the boiling point of the coolant, and failures due to heat on the sliding surface in the shaft seal part are prevented. This has the excellent effect of being able to reliably prevent this, thereby improving sealing performance and durability.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of the main part showing an embodiment of the mechanical seal according to the present invention, and FIG. 2 is a sectional view of the main part of the cooling water circulation supply mechanism part in the fixed sliding ring, taken along the line shown in FIG. 1. , FIG. 3 is an explanatory diagram showing the cooling state of the cooling water circulation supply mechanism section, and FIG.
FIG. 1 is a schematic cross-sectional view of a main part of a conventional mechanical seal. 1... Body (housing), 2... Rotating shaft, 5
...Rotating sliding ring (seal ring), 6... Fixed sliding ring (mating ring), 61... Evaporation space,
20...Cooling water circulation supply mechanism, 21...Cooling liquid injection nozzle, A...Sliding surface, W...Cooling liquid.

Claims (1)

[Scope of utility model registration request] In a mechanical seal in which a fixed sliding contact ring is in sliding contact with a rotating sliding contact ring, an evaporation space that reaches the vicinity of the sliding surface and is led out to the outside is provided in the fixed sliding contact ring, and an evaporation space that is inserted into the evaporation space is and a required number of coolant injection nozzles that open facing the sliding surface side end face of the space.