JPS6037462A - Mechanical seal of double ring - Google Patents

Abstract

PURPOSE:To improve cooling efficiency and to facilitate extracting of a seal ring by forming a void portion for cooling with an assembly of inner and outer fixed rings. CONSTITUTION:Inner and outer fixed rings 12, 13 are pressed to each other by a setscrew 15, and fixed to a fixed ring presser 16 by a torque pin. Then inner and outer fixed rings 12, 13 L-shaped in section are directly cooled by cooling water flowing through a passage formed by a void portion of the fixed rings. The fixed ring presser 16 is pressed to a tank cover by a bolt 20. The presser is divided into two at its periphery, and of a flange type to be easily detached and attached. Accordingly, a cooling chamber can be disassembled and cleaned, which can prevent lowering of a cooling effect caused by fur or the like.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a mechanical seal suitable for sealing a rotating shaft, and particularly to a double-ring mechanical seal for a low-pressure, low-speed stirring tank, a centrifugal thin film evaporator, etc. It is related to.

[Background of the invention]

In the fixed ring of integral structure (fixed ring with two sliding motions) shown in Utility Model Publication No. 47-7550.

For lazoping processing, it is required that the two sliding movements be located on the same plane (flushness). This means that when re-lapping a product that has been used once, the two surfaces lose their flushness due to the difference in the degree of wear, requiring an excessive amount of lapping, and in extreme cases, it may become impossible to re-lamp. there were.

[Purpose of the invention]

An object of the present invention is to improve the lapping process, facilitate the removal of seal rings (rotating ring, fixed ring), and provide a double-ring mechanical seal having more advanced functions.

[Summary of the invention]

In the present invention, the fixed ring is composed of two rings, and the combined fixed ring forms a cooling cavity.

A rigid foot ring presser divided in the circumferential direction is attached to the tank lid.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, 1 is a shaft, 2 is a spring bearing set on the shaft, and an inner rotating ring 3 and an outer rotating ring 4 are inserted in parallel in the radial direction into this hollow space.

These rotating rings 3 and 4 have a built-in shaft sealing spring 5, and the repulsive force thereof prevents them from lifting up during rotation and sliding. The O-ring 6 is enclosed between the spring bearing 2 and the inner and outer rotating rings 3.4, and seals the sealant in the shaft sealing chamber.

Further, an O-ring 7 is inserted between the spring bearing 2 and the shaft l,
Seal the fluid in the tank. 12 is an internal fixing ring, 13 is an external fixing ring, 10 is a Q + J ring, and has an L-shaped cross section.
This prevents leakage from the dividing surface of the external fixing rings 12 and 13, and seals the cooling water flowing through the formed cavity. Reference numeral 9 denotes an O-ring inserted between the external fixing ring 13 and the tank lid to seal the fluid in the tank. However, spring holder 2. A shaft sealing chamber is formed by the inner and outer rotating rings 3.4, the inner and outer fixed rings 12 and 13, and the OIJ song and lO, and the sealant is sealed therein.

The O-ring 8 in FIG. 1 and the O-ring 11 in FIG. 2 are sealing O-rings provided at the openings of the inner fixed ring 12 that penetrate into the shaft sealing chamber and the cooling water chamber. The sealant inlet/outlet pipe 14 shown in FIG. 2 is welded and fixed to the outer fixing ring 13.

The rotation of the shaft 1 is transmitted to the spring bearing 2 by a set screw 17, and is transmitted to the inner and outer rotating rings 3.4 by a torque pin 18. The inner and outer fixing rings 1.2 and 13 are set screws 15 (
(FIG. 1) and is fixed to the fixing member 16 by a torque pin 19. The inner and outer fixed rings 12 and 13, which have an L-shaped cross section, are directly cooled by cooling water flowing through the hollow portions thereof.

The fixing pedestal 16 is screwed onto the tank lid using bolts, and the presser foot is divided into two circumferential parts and has a flange shape that can be easily attached and detached. Therefore, the inner and outer fixing rings 12
, 13 can be easily pulled out by removing the fixing mechanism, and there is no need to remove the tank lid, so the sliding surface of these seal rings can be easily inspected. Further, in one indirect cooling, it was impossible to clean the inside of the jacket, but in this embodiment, it is possible to disassemble and clean the cooling chamber, thereby making it possible to prevent deterioration of the cooling effect due to limescale, etc. Therefore, by using the semi-balanced outer rotating ring, it is possible to reduce the sliding surface pressure (P), which is inversely proportional to the increase in sliding speed (V).
), the Pv value, which is said to affect the performance of the cell, can be controlled within the Pv value.

They can be made equal in the outer rotation ring. In addition, by combining a fixed ring with two sliding surfaces into one ring corresponding to one sliding surface and forming a fixed ring by combining two rings, the amount of lapping of the sliding surface can be reduced to two surfaces. Compared to occasional processing, frost can be reduced, and re-wrapping after use can be performed using the same method as conventional mechanical seals, significantly reducing maintenance costs.

By creating a cavity in the combined cross section of the two seal rings and creating a structure that allows water to cool through it, cooling efficiency is significantly improved compared to indirect cooling methods using jackets, etc., and compared to the conventional double ring mechanical method. In seals, sealant was mainly supplied using a forced circulation method, but in this example, it is now possible to use a method in which sealant is pressurized and sealed using a fixed ring with a built-in direct cooling chamber, which greatly reduces operating costs. Can be reduced.

〔Effect of the invention〕

According to the present invention, the lazoping process and the extraction of the seal ring are facilitated, and there is an effect that the seal ring has a more advanced function as a mechanical seal.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of the mechanical seal according to the present invention, @2
The figure is a sectional view of the sealant inlet/outlet pipe and the portion where the torque pin is used.

Claims (1)

[Claims] 1. A combination of inner and outer fixed rings that correspond to the inner and outer rotating rings in a double-ring mechanical seal in which the inner and outer rotating rings and the inner and outer fixed rings are pulled out to inspect their sliding movement. This double-ring mechanical seal is characterized by forming a cooling cavity in the tank lid, and by dividing the fixed ring retainer in the circumferential direction and attaching it to the tank lid.