CN209925617U

CN209925617U - Packing sealing device

Info

Publication number: CN209925617U
Application number: CN201920710897.5U
Authority: CN
Inventors: 谢宗海; 刘世雄; 李振铭; 董昌吉; 许亚茹; 刘振兴; 宋国军; 李东阳; 李�瑞; 张军平
Original assignee: Qinghai Salt Lake Industry Co Ltd
Current assignee: Qinghai Salt Lake Industry Co Ltd
Priority date: 2019-05-17
Filing date: 2019-05-17
Publication date: 2020-01-10
Anticipated expiration: 2029-05-17

Abstract

The utility model discloses a packing sealing device, which comprises a shaft, wherein a packing sealing part and an end cover sealing box are arranged outside the shaft, the packing sealing part comprises a packing group gland, a floating packing box, an O-shaped ring, a packing gland and packing, and the O-shaped ring is arranged between the floating packing box and the end cover sealing box to provide elasticity for the floating packing box; the packing is arranged between the floating packing box and the shaft so as to seal the shaft; the gland is coupled to the floating stuffing box to compress the stuffing against the surface of the shaft. The stuffing sealing device utilizes the floating stuffing box and the O-shaped ring to compensate the stuffing in the radial direction, so that the stuffing keeps floating in the radial direction, and the problem of stuffing sealing failure caused by the misalignment of the center of the shaft and the rotation center is solved.

Description

Packing sealing device

Technical Field

The utility model discloses the general relates to move equipment sealing technical field, more specifically relates to a packing sealing device.

Background

The packing seal is also called as a compression packing seal, commonly called packing, is the oldest seal structure, and in ancient water lifting machinery in China, the leakage is blocked by a method of filling cotton yarns. The packing seal is still used up to now because of its simple structure, low price and reliable seal. At present, the packing seal is mainly used for the dynamic seal of moving parts of process machines and equipment in the mechanical industry, such as centrifugal pumps, compressors, vacuum pumps, mixers, rotating shaft seals and reciprocating compressors of reaction kettles, reciprocating shaft seals of refrigerants, rotary seals of valve stems of various valves and the like.

A conventional packing structure is shown in fig. 1, in which a packing 12 is installed in a stuffing box 11, and the packing 12 is pressed against the surface of a shaft 14 by a packing gland 13. After the packing 12 is filled in the packing cavity, it is axially compressed by the packing gland 13, and when the shaft 14 and the packing 12 move relatively, it generates radial pressing force due to the plasticity of the packing 12 and is tightly contacted with the shaft 14. Since the surface of the shaft 14 is always somewhat rough, it is only partially in contact with the packing 12, and not in contact with it. Meanwhile, the sealant impregnated in the filler 12 is extruded to form an oil film between the contact surfaces, and since the contact state is not particularly uniform, a "boundary lubrication" state, called a "bearing effect", occurs at the contact portion; the concave part which is not contacted forms a small oil groove with a thicker oil film, and the contact part and the non-contact part form an irregular labyrinth to play a role in preventing the medium under pressure from leaking, which is called as a labyrinth effect. It follows that a good packing seal consists in maintaining the "bearing effect" and the "labyrinth effect", that is to say, maintaining good lubrication and adequate compression. Poor lubrication, or excessive compression, can disrupt the oil film, resulting in dry friction between the packing 12 and the shaft 14, eventually leading to shaft seizure and severe wear. For this reason, it is necessary to frequently adjust the degree of pressing of the packing 12 so that the sealing liquid in the packing 12 is squeezed out after running for a certain period of time while compensating for the relaxation of the pressing force of the packing 12 due to the change in volume.

However, when the mechanical equipment works, the shaft has larger vibration and deflection, and larger eccentricity will occur between the center of the shaft and the rotation center. As shown in fig. 2, if the center of the shaft 14 does not coincide with the rotation center and the eccentricity is e, the maximum clearance between the shaft 14 and the packing 12 is 2 e. The distribution of the gaps along the circumference is like a crescent, and the positions of the gaps of the crescent are periodically changed along with the rotation of the shaft 14, so that the packing 12 is in sealing failure and short in service life. Therefore, for shafts 14 with large vibrations and runout, the packing must be compensated in the radial direction, otherwise the packing 12 wear is accelerated, the seal life is shortened and the sealing effect is reduced.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a packing sealing device, the device accessible is floated packing box and O type ring and is compensated the packing in radial direction to solve the problem of the packing seal inefficacy that leads to because of the center of axle does not coincide with the rotation center.

In order to solve the technical problem, the utility model adopts the following technical scheme: a packing seal device comprises a shaft, wherein a packing seal component and an end cover seal box are arranged outside the shaft, the packing seal component comprises a packing set gland, a floating packing box, an O-shaped ring, a packing gland and packing, and the packing set gland is connected with the end cover seal box to axially fix the floating packing box; the O-shaped ring is arranged between the floating stuffing box and the end cover sealing box to provide elasticity for the floating stuffing box; the packing is arranged between the floating packing box and the shaft so as to seal the shaft; the gland is coupled to the floating stuffing box to compress the stuffing against the surface of the shaft.

Preferably, the floating stuffing box is provided with a supporting part, the top end of the supporting part is provided with a groove, and the groove is used for fixing the O-shaped ring.

Preferably, the groove is a semicircular groove, and the diameter of the groove is the same as the diameter of the cross section of the O-ring.

Preferably, two or more O-rings are arranged between the floating stuffing box and the end cover sealing box.

Preferably, the supporting parts on the floating stuffing box are respectively arranged at two ends of the floating stuffing box.

Preferably, the O-ring is a metallic inflatable O-ring.

Preferably, the O-ring is filled with an inert gas.

Preferably, the packing group gland is connected with the end cover sealing box through a first bolt, and the packing gland is connected with the floating packing box through a second bolt.

Preferably, wear-resistant O-rings are arranged on two sides of the floating stuffing box to prevent the floating stuffing box from being worn when floating.

Preferably, a gap is left between the packing set gland and the packing gland to allow the packing gland to float with the floating stuffing box.

Preferably, the packing gland and the packing group gland are respectively provided with an inosculating beam and an inosculating groove which can be mutually embedded, so as to prevent the packing gland from rotating along with the shaft.

Preferably, the end cover sealing box is provided with a cooling liquid hole so as to introduce cooling liquid between the end cover sealing box and the floating packing box.

Preferably, the end cover sealing box and the floating packing box are both provided with cooling liquid sealing holes so as to introduce sealing liquid into the packing.

Compared with the prior art, the utility model provides a pair of packing sealing device has following advantage: the floating stuffing box and the O-shaped ring are used for compensating the stuffing in the radial direction, so that the stuffing keeps floating in the radial direction, and the problem of stuffing sealing failure caused by the misalignment of the center of the shaft and the rotation center is solved; the device has the advantages of simple structure, low cost and convenient installation and maintenance, and can effectively prolong the service life of the packing seal.

Drawings

Fig. 1 is a schematic view of a conventional packing structure.

Fig. 2 is a schematic view of a structure in which the center of the shaft does not coincide with the center of rotation.

Fig. 3 is a schematic structural diagram of the packing sealing device provided by the present invention.

FIG. 4 is a partial isometric view of the floating stuffing box shown in FIG. 3 connected to an O-ring.

Fig. 5 is a left side view of the filler sealing device of fig. 3.

Fig. 6 is a schematic structural diagram of another embodiment of the present invention.

Reference numerals:

20-shaft sleeve, 21-shaft,

22-end cover sealing box, 23-packing group gland,

24-a floating stuffing box, 241-a support part,

242-grooves, 25-O-rings,

26-packing gland, 27-packing,

28-first bolt, 29-second bolt,

210-wear resistant O-ring, 211-gap,

261-kiss beam, 231-kiss groove,

212-coolant holes, 213-coolant seal holes,

214-liquid seal ring.

Detailed Description

The preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like elements and techniques of the present invention so that advantages and features of the present invention may be more readily understood when implemented in a suitable environment. The following description is an embodiment of the present invention, and other embodiments related to the claims that are not explicitly described also fall within the scope of the claims.

Fig. 3 shows a schematic structural diagram of the packing seal device provided by the present invention, which is illustrated by taking a centrifugal pump as an example, and is a sectional view of the packing seal device after being cut into four parts to show the internal structure, although in practice, the packing seal device is a complete whole.

As shown in fig. 3, the stuffing seal device comprises a shaft 21, a stuffing seal component and an end cover sealing box 22 are arranged outside the shaft 21, and the stuffing seal component comprises a stuffing set gland 23, a floating stuffing box 24, an O-shaped ring 25, a stuffing gland 26 and a stuffing 27.

The packing set gland 23 is connected with the end cap gland 22 to axially fix the floating packing box 24; the O-ring 25 is arranged between the floating stuffing box 24 and the end cover sealing box 22 to provide elasticity for the floating stuffing box 23; the packing 27 is arranged between the floating packing box 24 and the shaft 21 so as to seal the shaft 21; the packing gland 26 is connected to the floating packing box 24 to compress the packing 27 against the surface of the shaft 21.

The stuffing sealing device is not only suitable for sealing the pump shaft of the centrifugal pump, but also suitable for sealing the rotating shaft and the reciprocating shaft of a compressor, a vacuum pump, a stirrer, a reaction kettle, a reciprocating compressor, a reciprocating shaft of refrigerant and valve rods of various valves so as to prevent the medium leakage phenomenon.

The shaft 21 may be sleeved with a cylindrical sleeve 20 on the outside to protect the shaft 21 from abrasion.

The packing set gland 23 serves to axially secure the floating packing box 24, where axial is in the axial direction. The O-ring 25 has a compression deformation function, is arranged between the floating stuffing box 24 and the end cover sealing box 22, and can provide elasticity for the floating stuffing box 23 so as to play a role in buffer compensation. Meanwhile, the O-ring 25 arranged between the floating stuffing box 24 and the end cover sealing box 22 also plays a role in sealing, and leakage between the floating stuffing box 24 and the end cover sealing box 22 is prevented.

The filler 27 is a material filled in the floating stuffing box 24, mainly uses graphite and various fibers as main materials, and can also be reinforced by carbon fibers, copper wires, stainless steel, Yinchengai nickel alloy wires and other materials according to different requirements. The materials used as fillers should have the following characteristics: the packing has certain elasticity and plasticity, and can generate larger radial pressing force and be tightly contacted with the shaft when the packing is axially pressed; the shaft is slightly eccentric and can have certain floating elasticity; the sealing filler has enough chemical stability, does not pollute a medium, is not corroded and swelled by the medium, is not dissolved by the medium, and does not corrode a sealing surface; the self-lubricating property is good, the friction coefficient is small and the wear resistance is good; the temperature resistance is realized, and the heat-resistant rubber can bear a certain temperature after friction heating; convenient disassembly, simple manufacture and low cost.

The packing gland 26 may compress the packing 27 against the surface of the shaft 21, causing the packing 27 to be under axial compression, and thereby causing the packing 27 to exert a greater radial compression on the shaft 21.

The packing 27 is installed in the floating stuffing box 24 and is axially compressed by the packing gland 26, when the shaft 21 runs, the shaft 21 and the packing 27 move relatively, and due to the plasticity of the packing 27, the packing 27 generates radial pressing force to tightly contact the shaft 21 for sealing.

When mechanical equipment works, the shaft 21 has larger vibration and deflection, and according to the packing sealing principle and the operation condition, a radial compensation device needs to be added to a packing sealing component so as to ensure that the packing 27 keeps floating in the radial direction, thereby avoiding the problems of abrasion and sealing failure of the packing 27 caused by the misalignment of the center of the shaft 21 and the rotation center. Therefore, the utility model provides a packing sealing device has increased unsteady packing box 24 and O type ring 25, when axle 21 has great vibration and beat, the O type ring of installing between unsteady packing box 24 and end cover seal box 22 is compressed deformation, can carry out radial compensation to unsteady packing box 24, and then makes packing 27 keep floating in radial direction to solve the problem of the sealed inefficacy of packing that leads to because of the center of axle and rotation center do not coincide.

Fig. 4 shows a partial perspective view of the floating stuffing box in connection with an O-ring.

As shown in fig. 4, a supporting portion 241 is provided on the floating stuffing box 24, a groove 242 is provided on the top end of the supporting portion 241, the groove 242 is used for fixing the O-ring 25 to prevent the O-ring 25 from moving freely when the shaft 21 rotates, and meanwhile, the floating stuffing box 24 is installed in the end cap sealing box 22 and is radially positioned by the O-ring.

The groove 242 is a semicircular groove, and the diameter of the groove 242 is the same as the diameter of the cross section of the O-ring 25, so that the O-ring 25 is firmly confined in the groove 242.

Two or more O-rings may be provided between the floating stuffing box 24 and the end cap sealing box 22 depending on the compensation requirements of the floating stuffing box and the pressure of the sealing system.

The supporting parts 241 of the floating stuffing box 24 are respectively arranged at two ends of the floating stuffing box 24, so that two or more O-rings play a role in stably compensating the floating stuffing box 24.

The O-shaped ring is a metal inflatable O-shaped ring and is formed by bending a seamless metal round tube, inert gas is filled in the ring to form positive pressure, elasticity is generated, and vibration and deflection of the floating packing box 24 are compensated.

The packing group gland 23 is connected with the end cover sealing box 22 through a first bolt 28, and the packing gland 26 is connected with the floating packing box 24 through a second bolt 29.

Wear-resistant O-rings 210 are installed on both sides of the floating stuffing box 24 to prevent the floating stuffing box 24 from being worn when floating. The wear-resistant O-shaped ring 210 is made of polytetrafluoroethylene, can prevent the floating stuffing box 24 from being worn by the rear pump cover and the stuffing set gland 23 when floating, and plays a role in auxiliary sealing and axial positioning. In this embodiment, two wear-resistant O-rings 210 are mounted on each side of the floating stuffing box 24.

Fig. 5 shows a left side view of the stuffing seal.

As shown in fig. 5, a gap 211 is left between the packing set gland 23 and the packing gland 26 to allow the packing gland 26 to float with the floating stuffing box 24. Since the packing gland 26 and the floating packing box 24 are fixed by the second bolt 29, the floating packing box 24 drives the packing gland 26 to float together when floating, and therefore, a certain gap is required between the packing group gland 23 and the packing gland 26 to ensure the floating requirement.

The packing gland 26 and the packing gland 23 are respectively provided with an inosculating beam 261 and an inosculating groove 231 which can be mutually inosculated so as to prevent the packing gland 26 from rotating along with the shaft 21, and when the packing gland 26 cannot rotate along with the shaft, the floating packing box 24 cannot rotate along with the shaft.

The end cover sealing box 22 is provided with a cooling liquid hole 212 so as to introduce cooling liquid between the end cover sealing box 22 and the floating stuffing box 24, and thus the floating stuffing box 24 and the stuffing 27 are cooled.

Fig. 6 shows a schematic structural diagram of another embodiment provided by the present invention.

As shown in fig. 6, cooling sealing liquid holes 213 are provided in both the end cap sealing box 22 and the floating stuffing box 22 to introduce sealing liquid into the stuffing 27.

In a packing sealing device, it is usually necessary to introduce a sealing liquid into the packing 27 to provide a good lubricating effect for the packing 27, and to take away heat from the sealing cavity in time, and finally to improve the working environment of the mechanical seal. The sealing liquid is generally low-viscosity oil, water and the like which can not react with and pollute the medium, and is volatile and is avoided. Commonly used are soft water, ethylene glycol + water, engine oil, white oil, and the like. When sealing liquid needs to be introduced into the filler 27, the liquid sealing ring 214 is arranged at the position opposite to the opening, and the liquid sealing ring 214 plays a role in guiding the sealing liquid to form a sealing cavity.

The utility model provides a pair of packing sealing device's purpose is extension packing seal life, ensures sealing system steady operation.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Claims

1. The packing sealing device is characterized by comprising a shaft (21), a packing sealing component and an end cover sealing box (22) are arranged outside the shaft (21), the packing sealing component comprises a packing group gland (23), a floating packing box (24), an O-shaped ring (25), a packing gland (26) and packing (27),

the packing group gland (23) is connected with the end cover sealing box (22) so as to axially fix the floating packing box (24);

the O-ring (25) is arranged between the floating stuffing box (24) and the end cover sealing box (22) to provide elasticity for the floating stuffing box (24);

the packing (27) is arranged between the floating packing box (24) and the shaft (21) to seal the shaft (21);

the packing gland (26) is connected to the floating packing box (24) to compress the packing (27) against the surface of the shaft (21).

2. The stuffing seal according to claim 1, characterized in that a support (241) is provided on the floating stuffing box (24), the top end of the support (241) being provided with a groove (242), the groove (242) being used for fixing the O-ring (25).

3. The stuffing seal according to claim 2, characterized in that the groove (242) is a semicircular groove, the diameter of the groove (242) being the same as the cross-sectional diameter of the O-ring (25).

4. The stuffing seal according to claim 3, characterized in that two or more O-rings (25) are provided between the floating stuffing box (24) and the end cap sealing box (22).

5. The stuffing seal according to claim 4, characterized in that the O-ring (25) is a metal inflatable O-ring.

6. The stuffing seal according to claim 1, characterized in that the stuffing group gland (23) is connected with the end cap gland (22) by first bolts (28), and the stuffing gland (26) is connected with the floating stuffing box (24) by second bolts (29).

7. The stuffing seal according to claim 1, characterized in that wear resistant O-rings (210) are installed on both sides of the floating stuffing box (24) to prevent the floating stuffing box (24) from wearing when floating.

8. The stuffing seal according to claim 1, characterized in that a gap (211) is left between the stuffing group gland (23) and the stuffing gland (26) to allow the stuffing gland (26) to float with the floating stuffing box (24).

9. The stuffing seal according to claim 8, characterized in that the stuffing gland (26) and the stuffing group gland (23) are provided with an anastomosis beam (261) and an anastomosis groove (231), respectively, which can be engaged with each other, to prevent the stuffing gland (26) from rotating with the shaft (21).

10. The stuffing seal according to claim 1, characterized in that cooling liquid holes (213) are provided in both the end cap sealing box (22) and the floating stuffing box (24) for introducing sealing liquid into the stuffing (27).