RU1772383C - Face seal for turbine shaft - Google Patents

Abstract

Usage: gas turbine engineering, in particular with dry gas mechanical seals of turbomachine shafts. SUMMARY OF THE INVENTION: A seal consists of a rotary ring 1. Spring-loaded with an axial spring 2, a stator ring 3, Spring-loaded with an axial spring 4. The seal is equipped with specially profiled keys 5. The keys 5 are located in the radial plane in the grooves in the rotary shaft 1 and in the sleeve 6 of the shaft 7. The dowels 5 serve both to transmit torque from the shaft 7 to the rotary ring 1, and to create an axial clearance between the sealing end surfaces of the rotary ring 1 and the stator ring 3 by axial displacement audio rotary ring 1 to the opposite side of the stator ring 3. 2 ly z.p.f-2-yl. J s 4

Description

The invention relates to the field of the gas industry, in particular to dry gas mechanical seals of a turbo-machine shaft,

Mechanical seals of pipe shaft machines are known, the disadvantage of which is a large loss of power for the operation of the seal, significant operating costs, large dimensions and weight of the seal.

The closest technical solution to the invention is a dry gas mechanical seal, which contains a graphite stator ring loaded with springs, the mechanical sealing surface of which is in contact with the mechanical sealing surface of the tungsten carbide rotating ring, which sits rigidly on the shaft of the turbomachine. On its end surface, on the side of the stator ring, in the region of the inner diameter, there is a sealing annular juice to which a spring-loaded stator ring is pressed against the tube machine in a one hundred night operation. Along the periphery of the rotating ring there are spiral grooves with which ribs are formed which act as compressor blades.

In dynamics, during the rotation of the shaft of the Turbo-machine, gas is captured by the blades and is pumped to the mechanical seal along the skew. The pressure increased in this way, before sealing, overcomes the spring resistance of the stator ring and pushes it in the axial direction until a working gap arises between the stator ring and the rotating ring. In this way, an axial clearance arises between the sealing end surfaces of the rings, ensuring trouble-free operation of the sealing of high-speed turbomachines.

The disadvantages of this seal design are the structural and technological complexity of making a seal due to the accepted principle of separating the sealing rings by pumping gas into the gap between them to overcome the resistance of the stator ring spring; insufficient reliability of the structure due to the rigid connection of the rotating ring with the shaft, which can lead to angular deviations of the sealing end surfaces due to thermal deformations and possible deflections of the shaft, which will worsen the working conditions of the seal; increased gas flow through the gap between the ends of the o-rings, because the seal operates on the principle of gas injection by the blades of a rotating ring to the end face of the seal; expenditure of a part of the power of a turbomachine for pumping gas with a spatula.

rings to the sealing ring; due to a certain profiling of the blades of a supercharger of a rotating ring, the seal is structurally attached to a certain side of rotation of the shaft, which does not allow

0 Opportunities to perform a unified seal.

The aim of the invention is to increase the economy and reliability of the seal, as well as the creation of a unified design of the mechanical seal, regardless of the direction of rotation of the shaft of the turbomachine.

The goal is achieved by a new design of the seal, in which the disengagement of the sealing rings is carried out by a spring-and-spring mechanism using centrifugal forces acting on the key, with a greater degree of freedom of the rotating ring relative to the shaft

5 turbomachines.

Such a method of disassembling the sealing rings improves the cost-effectiveness of the seal.

Instead of an uneconomical way to disconnect the sealing rings during operation of the turbomachine using a gas blower on a rotating ring, which increases the gas flow through the seal, disconnection is carried out using several

5 specially profiled keys placed between the rotary ring and the shaft of the turbomachine in radial planes.

These keys serve simultaneously

0 to transmit torque from the shaft to the rotating ring, thereby increasing the reliability of the seal.

Due to the increase in the degree of freedom of the rotating ring relative to the shaft of the turbomachine, this ring in operation will be in the field of its centrifugal forces and will not be affected by a change in the axis of rotation of the shaft due to vibration and possible shaft dying than

0 eliminates the possibility of angular displacements of the end face of the rotating ring relative to the stator ring. This creates a unified seal design, independent of the side of rotation, which improves the environmental friendliness of the turbomachine due to less gas leaks through the shaft seal into the atmosphere.

Sealing end faces

rotating and stator rings can

be made both conical and perpendicular to the axis of the shaft.

In the case of a conical mechanical seal, the axial clearance between the sealing mechanical surfaces will be additionally created by tensile centrifugal forces acting on the rotating ring.

Fig. 1 shows a longitudinal section through a mechanical seal of a shaft of a turbomachine with conical sealing surfaces; Fig. 2 is a longitudinal section through a mechanical seal of a shaft of a turbomachine with sealing surfaces perpendicular to the axis of the shaft;

The mechanical shaft seals of the turbomachine shown in FIG. 1 and 2, consist of the following parts: a rotating sealing ring 1, an axial spring 2 of a rotating sealing ring 1, a stator sealing ring 3, an axial spring 4 of the stator sealing ring 3, specially profiled sealing keys 5, a sleeve b on the shaft turbomachines, shaft 7 turbomachines.

When the shaft 7 rotates, the key 5 performs two functions: it transfers the torque from the shaft 7 to the rotary ring 1, disconnects the sealing rings, the rotary ring 1 and the stator ring 3, until an axial clearance is created between them.

To this end, correspondingly spherical end surfaces of the dowels 5 in the rotary ring 1 and in the sleeve 5 of the shaft 7 are mating grooves into which the dowels 5 are inserted.

In the stand-by mode of the turbomachine, the sealing rotary ring 1 under pressure of its axial spring 2 will abut against the stator ring 3 and, overcoming the resistance of the axial spring 4, will move the stator ring 3 in the axial direction until a calculated axial clearance b is formed between the stator ring 3 and the seal housing. In this case, the axis of the key 5 will be in an inclined position at an angle / to the axis of the shaft.

In dynamics, with an increase in the number of revolutions of the turbomachine shaft, the dowels 5 will act on the centrifugal forces F applied to the center of gravity of the dowels, which, relative to the pivot point of the dowels in the reciprocal groove in the sleeve 6 of the rotor 7, will create a MVr torque.

Torque MVp will rotate the key in the plane of the drawing to its radial position when the torque ceases.

5 In this case, under external pressure

of the end of the key 5 to the rotary ring 1, the latter, having overcome the resistance of the spring 2, will be displaced axially in the opposite direction from

10 of the stator ring 3. The stator ring 3, under the pressure of its axial spring 4, will follow in the axial direction the rotary ring 1 until a clearance is selected between the stator ring 3 and the seal housing. After that, by the moment the axis of the key 5 is in the radial position, there will be a working axial clearance between the rotating ring 1 and the stator ring 3, which will prevent damage

0 shaft seals of the high speed turbomachine. In this case, the gas from the high pressure zone A will be throttled to the low pressure zone B and further to the atmosphere.

In the drawings, bold

5 dots indicate the locations of the elastic seal in the seal structure to eliminate bypass gas flows.

Claims (3)

Shadow Formula Formula 0 1. The mechanical seal of the shaft of the turbomachine, comprising a sleeve mounted on the shaft, with a rotating ring mounted on it, a housing with a stator ring fixed in it to form an axial clearance, contacting the sealing end face with the counter end surface of the rotating ring, a spring, a pressing stator ring, characterized in that, with the aim of In order to increase economy and reliability, the seal is equipped with a key, an additional spring compressing the rotating ring, grooves are made in the sleeve and in the rotating ring, and the flange is installed in the latter with the possibility of rotation about its vertical axis. 2. Seal pop. 1, characterized in that the sealing end surfaces of the rotating and stator rings are conical. 3. Seal pop. 1, characterized in that the sealing end surfaces of the rotating and stator rings are made perpendicular to the axis 5 shaft. FIG. 2