RU2811847C1 - Sealing device - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: sealing device contains at least one sealing element and a protective ring installed in a core limited on one side by a collar, or a cage between two collars, while the interacting end surfaces of the ring and the collar are made conical, and the protective ring is made of a split non-metallic material with hardness exceeding the hardness of the material of the sealing element. On the other side of the sealing element, a thrust ring with a stop is installed, and the sealing device is equipped with an additional protective ring placed between the sealing element and the protective ring; in the middle part of the interacting end surfaces of the rings, mirror annular grooves are made to form a closed annular cavity in which the reciprocal a split spring ring made with the ability to constantly press the rings to the sealing surface. The joints of the split rings and the spring split ring can be located with equal angular distance between them.

EFFECT: improved sealing.

2 cl, 2 dwg

Description

The invention relates to devices for sealing two concentrically located surfaces, and can be used in the field of mechanical engineering, in particular, for sealing pistons, plungers and rods of volumetric machines, for example, pumps, as well as rotating shafts.

A piston is known containing a core with a cylindrical collar, at least one replaceable collar installed between the collar and the thrust ring (see patent for utility model No. 189595, F04B 53/14, F16J 1/01, pub. 05/28/2019, Bulletin No. 16).

The disadvantage of the known device is its insufficient service life due to the possibility of pinching the supporting part of the cuff into the gap between the collar and the sealing surface, which can lead to tearing off of the cuff.

A known piston contains a metal core with a cylindrical collar, at least one replaceable rubber cuff, a protective ring installed between the collar and the cuff, while the interacting surfaces of the cuff and ring are made conical (RF patent No. 2050491, IPC F16J 1/00, publ. 12/20/1995).

Equipping the piston with a protective ring made of non-metallic material reduces the contact pressure in the supporting part of the cuff.

The disadvantage of the known device is the insufficient service life due to pinching of the supporting part of the cuff into the increasing gap between the protective ring and the sealing surface during operation.

A sealing device is known for sealing two concentrically located surfaces, containing at least one sealing element and a protective ring installed in a core or cage between the collars, while the interacting end surfaces of the ring and collar are made conical, the protective ring is made of a split non-metallic material with hardness exceeding the hardness of the cuff material (see book: Anuriev V.I. Handbook of mechanical engineering designer. Vol. 3, - m,: Mechanical Engineering, 1978, pp. 199-202), which is accepted as a prototype.

The technical objective of the proposed invention is to increase the service life of the sealing device by eliminating pinching of the end part of the sealing element into the gap between the protective ring and the sealing surface.

The solution to this problem is achieved by the fact that in a sealing device for sealing two concentrically located cylindrical surfaces, containing at least one sealing element and a protective ring installed in a core or cage between the collars, while the interacting end surfaces of the ring and collar are made conical, the protective ring is made of split non-metallic material with a hardness exceeding the hardness of the cuff material; according to the technical solution, it is equipped with an additional protective ring placed between the sealing element and the protective ring; in the middle part of the interacting end surfaces of the rings, mirror annular grooves are made to form a closed annular a cavity in which a reciprocal split spring ring is placed with the possibility of constantly pressing the rings to the sealing surface.

The joints of the split rings and the spring split ring are located with equal angular distances between them.

A sealing device for sealing two concentrically located surfaces is illustrated in the drawings:

in fig. 1 shows a general view of the piston mounted on the rod;

in fig. 2 - sealing device of the plunger or rotating

shaft

A sealing device, for example, a piston, contains a core 2 mounted on a rod 1 with a collar 3. Protective rings 4 and 5, a sealing collar 6, a thrust ring 7 and a stop 8 are successively mounted on the core 2. The stop 8 is made, for example, in the form of a split spring ring installed on the annular groove of the core 2.

The interacting end surfaces of the ring 4 and the collar are made conical. In the middle part of the interacting end surfaces of the rings 4 and 5, mirror-like annular recesses 9 and 10 are made, for example, in the form of a torus surface with the formation of a closed cavity 11. The cross-section of the cavity 11 is a circle, and a reciprocal split spring ring 12 is placed in it round section. The outer diameter of the spring ring 12 in the unloaded state is greater than the maximum diameter of the cavity 11 of circular cross-section.

Protective rings 4 and 5 are made of non-metallic material, the hardness of which is greater than the hardness of the material of the cuff 6.

The core 1 is installed between stops 13 and 14, made, for example, in the form of a collar of the rod 1 and a nut.

A piston with rod 1 is installed in a cylinder 15, for example, of a piston pump (not shown in the figure) to form a working cavity 16.

The core 2 is equipped, for example, with a sealing element 17 to seal the gap between it and the rod 1.

The joints of the split rings 4, 5 and the spring split ring 12 can be located with an equal angular distance between them.

The sealing device of the plunger or shaft (not shown in Fig.) contains a thrust ring 20, a cuff 6, protective rings 5 and 4, a pressure ring 21 and a stop 22 mounted sequentially on a holder 18 (Fig. 2) with a cylindrical protrusion 19, made, for example, , in the form of a nut.

In the middle part of the interacting end surfaces of the rings 4 and 5 there are mirror-arranged, for example, circular, rectangular in cross-section, grooves 23 and 24 with the formation of a closed annular cavity 25. In the cavity 11 there is a reciprocal split spring ring 26 of rectangular cross-section. The inner diameter of the ring 26 in the unloaded state is less than the minimum diameter of the cavity 11.

The joints of the split rings 4, 5 and the spring split ring 26 can be located with an equal angular distance between them.

A sealing device, such as a piston, in a positive displacement pump works as follows.

When assembling the piston, fitting the split spring ring 12 into the annular groove 9, and then placing the ring 12 in the cavity 11 while fitting the ring 5 close to the ring 4 provides a slight radial movement of the rings 4 and 5. After placing the piston with rod 1 in the cylinder 15, rings 4 and 5, as well as the front part of the cuff 6, fit tightly to the sealing surface of the cylinder 15. As a result, the possibility of pinching the back part of the cuff 6 into the gap is eliminated.

During operation, wear occurs on the sealing surface of the cuff 6 and rings 4, 5. The constant pressing of rings 4 and 5 to the surface of the cylinder 15 under the action of the split spring ring 12 prevents the formation of a gap between the rings 4, 5 and the cylinder 15.

When the joints of the protective rings 4, 5 and the spring ring 12 are located at equal angular distances, a more uniform distribution of contact pressure is ensured between the surfaces of the rings 4, 5 and the sealing surface.

The operation of the sealing device for sealing the plunger, rod or shaft (Fig. 2) is carried out in a similar way.

Due to the fact that the inner diameter of the ring 26 in the unloaded state is less than the minimum diameter of the cavity 25 of rectangular cross-section, when equipped with the specified device of the plunger or shaft (not shown in the figure), rings 4 and 5 are always pressed against the sealing surface. Preventing a gap between the surfaces of the rings and the sealing surface eliminates the possibility of the end part of the cuff 6 being pinched into the gap.

Thus, the proposed sealing device makes it possible to increase the service life by eliminating the possibility of pinching the back part of the cuff into the gap.

Claims (2)

1. A sealing device for two concentrically located cylindrical surfaces, containing at least one sealing element and a protective ring installed in a core limited on one side by a collar, or a cage between two collars, and the interacting end surfaces of the ring and collar are made conical, wherein the protective ring is made of a split non-metallic material with a hardness exceeding the hardness of the material of the sealing element, characterized in that on the other side of the sealing element a thrust ring with a stop is installed, and the sealing device is equipped with an additional protective ring placed between the sealing element and the protective ring, in the middle Parts of the interacting end surfaces of the rings are made of mirror annular grooves to form a closed annular cavity in which a reciprocal split spring ring is placed with the possibility of constantly pressing the rings to the sealing surface. 2. The sealing device according to claim 1, characterized in that the joints of the split rings and the spring split ring are located with an equal angular distance between them.

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