SU1221430A1 - End seal - Google Patents

Description

The invention relates to mechanical engineering and can be used mainly in sealing technology, for example, in mechanical seals of rotating shafts.

The purpose of the invention is to simplify the design and allow the control of the magnitude of the contact load in a pair of friction without stopping the machine by imparting to the seal the functions of the safety valve.

FIG. 1 shows schematically the mechanical seal S-section; in fig. 2 is a graph of the contact load in a pair of friction versus the pressure of the fluid in the seal chamber.

The mechanical seal consists of a non-rotating 1 and a rotating 2 sealing rings, which are pressed against each other by their end surfaces. The rotating ring 2 is sealed to the shaft 3 by means of a rubber ring 4 and is fixed on the shaft by means of a collar 5 and a nut 6.

The non-rotating sealing ring 1 is made in the form of a stepped piston, sealed in the housing 7 by rubber rings 8 and 9. Between these rings there is a chamber filled with liquid, such as oil, and connected hydraulically to the bottom of the cylinder 10. In the cylinder 10 there is the lower piston 11 and the upper piston 12, between which a compression spring 13 is mounted. The rod space of cylinder 10, above the upper piston 12), is hydraulically connected to the compacted cavity of the machine (seal chamber) and is always under pressure from the compacted fluid P. The sub-piston space of the cylinder 10 (under the piston 11) is under the pressure of oil P ,, which is proportional to the force 13 and the cross section

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piston 11. The piston 12 is equipped with a travel stop, made in the form of a nut 14, screwed on the piston rod 15 of the piston 12.

5 Compaction work as follows.

. In the absence of fluid pressure P in the seal chamber, piston 12 is abraded by spring 13.

 The top cover of the cylinder 10. In this position, the spring 13 will exert pressure on the piston 11 with a pre-compression force F.

As the pressure of the liquid 15 of the bone P in the chamber of the seal is increased, the spring. 13 will be compressed by the piston 12 and the force of compression of the spring will be transmitted to the piston 11. The oil pressure P will also increase and, consequently, the specific load Rc. Will increase. With further increase in pressure P, the force F of the spring compression will increase as long as it is limited. 14 doesn’t rest against the cylinder 10.

When determining the pressure P, the force on the left and on the right is matched, then Rzo O and the seal will open.

30 The seal can work in two zones from O to point q and from point b о P. |, р In the zone from point O to point t, the seal cannot work, since Pc is the permissible loadJJ ki. As a rule, all machines operate at a certain value of the working pressure R.

The cylinder bore 10 with pistons 11 and 12 on one side allows

40 to reduce the spring and seal haberrts in general, and on the other hand, it allows to adjust the contact pressure in the friction pair using the stroke cutter 14 without stopping the machine.

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Claims (1)

END SEAL, comprising a housing and a piston pressed against each other, sealed in the housing along two cylindrical surfaces, between which a chamber is connected in communication with a pressure source, characterized in that, in order to simplify the design and provide the ability to control the magnitude of the contact load in the friction pair without machine stops, the pressure source is made in the form of a cylinder with two pistons, between which a spring is installed, while the chamber is communicated through this cylinder with a seal, rotating and non-rotating the entire o-rings, the last of which is made in the form of a step cavity, and the piston in contact with the liquid being sealed has an adjustable stroke limiter of »ω s Fie! ” ί