RU192775U1 - Explosion-proof cable entry - Google Patents

Abstract

The utility model relates to cable entries - devices for the mechanical and electrical connection of armored and unarmored cables of circular cross section with stationary, mobile or portable electrical equipment. The utility model is used in places where it is necessary to provide an explosion-proof connection of the cable to electrical equipment. The explosion-proof cable entry contains a housing with a cylindrical through hole provided with a thread, a pressure ring installed in the hole, a sealing ring and a fitting, as well as a shank with a cylindrical through hole equipped with a supporting conical surface, a conical-cylindrical sealing ring installed in the hole so that the supporting the conical surface of the shank is associated with the conical base of the conical-cylindrical sealing ring. The housing is screwed onto the shank. A nozzle is screwed onto the fitting. A conical-cylindrical sealing ring is conjugated with a pressure ring by its end face, and is coupled with a shank with its cylindrical surface, which significantly improves the crimping of the inner cable sheath and increases the sealing and explosion-proofness of the cable entry. In turn, improved crimping of the inner sheath increases protection against pulling and transmission of torsional and pulling forces through the cable to the contact terminals. Providing the outlet outlet with both internal thread and external thread ensures the versatility of the external connection of the cable entry. Such a universal external connection of the cable entry with protective elements improves its protection against adverse environmental factors, which helps to increase the reliability and safety of the cable entry. Thus, the utility model helps to create a reliable and safe explosion-proof cable entry with universal external connection.

Description

The utility model relates to cable entries - devices for the mechanical and electrical connection of armored and unarmored cables of circular cross section with stationary, mobile or portable electrical equipment. The utility model can be used in places where it is necessary to provide an explosion-proof connection of the cable with electrical equipment.

Known explosion-proof cable entry according to the patent of the Russian Federation No. 155936 (IPC F21V 25/12, publ. 08/20/2016). The known cable entry comprises a housing with a cylindrical through hole provided with a thread, a pressure ring, a sealing ring and a fitting installed in the hole. The tail of the housing is provided with a mounting thread for screwing into the mounting wall of the electrical equipment.

When tightening the fitting, the O-ring compresses and compresses the outer surface of the cable.

A disadvantage of the known explosion-proof cable entry is the low reliability and safety of its operation. This is due to the fact that the cable entry is not protected from dust and moisture entering through the fitting; and also due to the fact that only the outer sheath of the cable is crimped, transmission of tensile and twisting forces through the inner sheath of the cable to the contact terminals is not excluded.

In addition, the well-known cable entry cannot be used to connect with armored and shielded cable, due to the lack of fixing means for the armored sheath and shield, respectively.

Known explosion-proof cable entry KOVTVL (http://exd.ru/index.php?id=1184, free access), selected for the closest analogue. The cable entry is designed to ensure the connection of the armored and shielded cable with electrical equipment. Known cable entry contains the housing (A) (see Fig. 1 of the claimed utility model), screwed onto the shank (B). In the cylindrical through hole of the housing, a pressure ring, a sealing ring and a fitting are installed. The shank (B) is made with a cylindrical through hole (B) provided with a supporting conical surface. A conical-cylindrical sealing ring (G) is installed in the hole (B) of the shank (B), which is conjugated by its conical surface to the supporting conical surface of the shank (B). The pressure ring is made in the form of two bushings (D) and (E), conjugated by their conical surfaces. The housing is equipped with an inner collar with the possibility of abutment of the latter in the external collar of the fitting. A nozzle with an internal thread for external connection is screwed onto the fitting.

The sleeve (D) of the pressure ring located on the side of the shank (B) is made in the form of a single part with a cylindrical sleeve (3). And the conical-cylindrical sealing ring (G) is installed with its cylindrical part inside the specified sleeve (3), with a partial emphasis on the end of the conical part of the sealing ring (G) in the sleeve (3).

When screwing the housing (A) onto the shank (B), a sealing ring (not shown in Fig. 1) compresses the outer surface of the cable, bushings (D) and (E) fix the armor / shield between their conical surfaces, and the conical-cylindrical sealing ring (D) crimps the inner sheath of the cable.

The well-known explosion-proof cable entry is not reliable enough and safe in operation. This is due to the fact that the sleeve (D) of the pressure ring when tightening the housing (A) mechanically acts only on the conical part of the sealing ring (G), and the cylindrical part of the sealing ring (G) does not participate in crimping the cable, which negatively affects the quality of the cable crimping and to protect it from pulling out, and also does not exclude the transmission of twisting and pulling forces through the cable to the contact terminals.

Known cable entry is limited in terms of external connection. This is due to the inability to connect with protective elements, for example, flexible hoses, pipelines, metal hoses, etc., having an internal thread, which reduces the protection of the cable entry from adverse environmental factors, especially in the field.

Thus, the problem of creating a reliable and safe explosion-proof cable entry in operation remains relevant.

The technical result, which is achieved by the claimed utility model, is to increase the reliability and safety of the explosion-proof cable entry by improving the crimp cable seal.

Moreover, in the proposed cable entry increased protection from adverse environmental factors by improving its external connection with protective elements.

The technical result is achieved in that the explosion-proof cable entry, as well as the closest analogue, contains a housing with a cylindrical through hole provided with a thread, a pressure ring installed in the hole, a sealing ring and a fitting, as well as a shank with a cylindrical through hole equipped with a supporting conical surface, installed a conical-cylindrical sealing ring in the hole so that the supporting conical surface of the shank is mated with the conical base of the conical-cylindrical Skog sealing ring, wherein the housing is screwed onto the shank and is screwed on the pipe fitting.

Unlike the closest analogue, a conical-cylindrical sealing ring is conjugated with a pressure ring with its end, and is conjugated with a shank with its cylindrical surface.

In this case, the outlet of the nozzle is provided with internal and external threads. FIG. 1 illustrates the technical solution of the closest analogue.

The notation in FIG. 1: A - housing; B - shank; In - an aperture of a shaft; G - conical-cylindrical sealing ring; D - sleeve of the pressure ring; E - sleeve of the pressure ring; Z - a cylindrical sleeve.

The essence of the claimed utility model is illustrated by the following drawings:

FIG. 2 - end part of the cable (not included in the cable entry);

FIG. 3 - sectional design of explosion-proof cable entry.

The notation in FIG. 2:

1 - cable;

2 - electric cable core;

3 - the inner sheath of the cable;

4 - armor / cable shield;

5 - outer sheath of the cable.

The notation in FIG. 3:

6 - case;

7 - pipe;

8 - external thread of the pipe;

9 - internal thread of the pipe;

10 - fitting;

11 - a sealing ring of a cylindrical shape;

12 - pressure ring;

13 and 14 - conical bushings;

15 - reference plane;

16 - conical-cylindrical sealing ring;

17 - the cylindrical part of the conical-cylindrical sealing ring:

18 - conical part of the conical-cylindrical sealing ring:

19 - end face of a conical-cylindrical sealing ring;

20 - shank;

21 - mounting thread shank.

The cable entry in FIG. 3 comprises a housing 6 with a cylindrical through hole provided with a thread, a pressure ring 12 installed in the hole, a sealing ring 11 of cylindrical shape and a fitting 10. The housing 6 is screwed onto the external thread of the shank 20 with its internal thread. The shank 20 is made with a cylindrical through hole provided with a support a surface made in the form of a truncated cone. A conical-cylindrical sealing ring 16, conjugated by its base, made in the form of a truncated cone, with a supporting conical surface of the shank 20, is installed in the specified hole of the shank 20. The conical-cylindrical sealing ring 16 is conjugated with the pressure ring 12 with its end face 19, and its cylindrical surface is conjugated with a shank 20. The pressure ring 12 is made in the form of two conical bushings 13 and 14, conjugated by its conical surfaces. The housing 6 with its inner collar is connected with the external collar of the nozzle 10. A nozzle 7 is screwed onto the nozzle 10, the outlet of which is provided with an external thread 8 and an internal thread 9.

Cable entry is allowed for unarmoured cables. Explosion proof cable entry works as follows.

In the installation position, the end of the cable (Fig. 2) is prepared for installation in the cable entry. For this purpose, the outer sheath 5, the armor / shield 4 and the inner sheath 3 are removed in layers from the electric core 2. The cable entry shank 20 (Fig. 3), with its fastening thread 21, is screwed into the threaded hole of the electrical equipment mounting wall (not shown in Fig.). The specified threaded connection is made in accordance with the requirements of the standards for threaded flameproof joints. A sealant can be used to seal and lock the threaded connection. The housing 6 complete with a fitting 10 and a pipe 7, with a sealing ring 11 and a pressure ring 12 installed in the opening of the housing 6, form a housing assembly.

First, cable 1 is passed through the housing assembly until the outer sheath 5 of the cable is located in the sealing ring 11, and the ends of the armor / shield 4 are between the conical surfaces of the bushings 13 and 14. Then a thin part of the cable 1 is passed through a conical-cylindrical sealing ring 16 and a shank 20 , and enter the end of the cable 1 into the internal cavity of the electrical equipment.

Then screw the housing 6 onto the shank 20. When tightening the housing 6, the O-ring 11, made of elastic material, is compressed axially by the pressure ring 12, tightly fills the gap between the housing 6 and the outer surface of the cable, crimping the outer surface of the cable, thereby sealing the cable input. In this case, the armor / shield 4 is clamped between the mating conical surfaces of the tapered sleeves 13 and 14. At the same time, the pressure ring 12 compresses the conical-cylindrical sealing ring 16 made of elastic material, acting with its supporting plane 15 on the end face 19 of the sealing ring 16. When the pressure of the pressure ring 12 on the end face 19 of the sealing ring 16, located opposite its base, is compressed and the cylindrical part 17 and the conical part 18 of the sealing ring 16. When this m cable crimping is more effective due to the stop in the shank 20 of the entire side surface of the conical-cylindrical sealing ring 16, including the side surfaces and the cylindrical part 17, and the conical part 18 of the sealing ring 16. As a result, the sealing ring 16 tightly fills the entire gap between the shank 20 and the inner sheath 3 of the cable, providing sealing and explosion-proof cable entry. The emphasis of the inner collar of the housing 6 in the outer collar of the nozzle 10, fixing the engagement of the housing 6 by the nozzle 10, contributes to the better pressing of the nozzle 10 on the sealing ring 11 when tightening the housing 6, which improves crimping of the outer sheath 5 of the cable.

The coupling of the end face 19 of the conical-cylindrical sealing ring 16 with the supporting plane 15 of the pressure ring 12 provides pressure from the side of the pressure ring 12 both on the cylindrical part 17 and on the conical part 18 of the sealing ring 16. The effectiveness of said pressure increases due to the stop in the shank 20 of the whole the side surface of the conical-cylindrical sealing ring 16, including the side surfaces and the cylindrical part 17, and the conical part 18 of the sealing ring 16.

In general, this significantly improves the crimping of the inner sheath 3 of the cable and increases the sealing of the cable entry. In turn, improved crimping of the inner sheath 3 increases protection against pulling out and transmission of torsional and pulling forces through cable 1 to the contact terminals. As a result, the reliability and safety of the cable entry increases.

The execution of the outlet of the pipe 7 and with an internal thread 9, and with an external thread 8, allows you to connect with flexible hoses, pipelines, metal hoses, etc., respectively having an external or internal thread. Such a universal external connection of the cable entry with protective elements improves its protection against adverse environmental factors, which helps to increase the reliability and safety of the cable entry.

Claims (2)

1. An explosion-proof cable entry comprising a housing with a cylindrical through hole provided with a thread, a pressure ring installed in the hole, a sealing ring and a fitting, as well as a shank with a cylindrical through hole equipped with a supporting conical surface, a conical-cylindrical sealing ring installed in the hole in this way that the supporting conical surface of the shank is associated with the conical base of the conical-cylindrical sealing ring, while the housing is screwed onto the ostovik, and a nozzle is screwed onto the nozzle, characterized in that the conical-cylindrical sealing ring is conjugated with a pressure ring with its end, and is mated with a shank with its cylindrical surface. 2. Explosion-proof cable entry according to claim 1, characterized in that the outlet of the nozzle is provided with internal and external threads.

Images