RU200567U1 - POWER CABLE FLEXIBLE SHIELDED MINING - Google Patents

Abstract

The utility model relates to cable technology and is designed to connect self-propelled cars for underground mining. The technical result consists in ensuring explosion safety and increasing the strength of the cable. Three main and one auxiliary conductors are stranded from copper wires and covered with EPDM insulation. On top of the insulated three main and one auxiliary conductors, there is a screen made of electrically conductive rubber, an uninsulated grounding conductor is laid in the gap between the main conductors. The inner cable sheath is made of two layers, and its inner layer is made of electrically conductive rubber, and the outer layer is made of oil-resistant, flame retardant hose rubber. The outer sheath of the cable is made of oil-resistant hose rubber with increased resistance to abrasion and tear. Between the inner and outer shells there is a braid of strands twisted from electrically conductive threads. 1 ill.

Description

The utility model refers to cable equipment and is designed to connect self-propelled cars during underground mining with an electric drive to an alternating current network of 50 Hz at a nominal voltage of 1140 V on the main conductors and 220 V on the auxiliary conductors.

Known power flexible cable (patent RU No. 49346 publ. 10.11.2005), which consists of three main shielded conductors with rubber insulation, grounding conductors, auxiliary shielded conductors with rubber insulation of equal section with the main conductors, in a rubber sheath that does not spread combustion, insulated and shielded conductors are twisted around the grounding conductor with filling in the gaps between the conductors with reinforcing rubber bands based on synthetic threads.

Known power flexible cable (patent RU No. 176966 publ. 16.02.2018), which contains three main conductive conductors and auxiliary conductors, grounding conductor and outer sheath. The grounding conductors and the auxiliary conductor are covered with rubber insulation and an electrically conductive rubber shield. The conductors are twisted around a polymer core with filling of the inter-conductor space.

The disadvantage of the known technical solutions is the lack of advanced shutdown when exposed to crushing external load.

The technical problem solved by the claimed utility model is to exclude accidents as much as possible by early (until the insulation of the main conductors is damaged and a short circuit occurs) disconnecting the cable when exposed to a crushing external load, ensuring explosion safety and increasing the strength of the cable.

The technical result is achieved by the fact that in a power flexible shielded mine cable containing three main and auxiliary conductive conductors twisted from copper wires, each of which is covered with ethylene-propylene rubber insulation, and on top of the insulation there is a screen made of electrically conductive rubber, an uninsulated grounding conductor laid in the interval between the main cores, the central core and the inter-core reinforcing harnesses, the inner and outer rubber sheaths, according to the proposed solution, a braid of strands twisted from electrically conductive threads is located between the inner and outer shells, while the inner shell is made of two-layer, the inner layer of which is made of electrically conductive rubber, and the outer layer is made of oil-resistant flame-retardant hose rubber, the outer sheath of the cable is made of oil-resistant with increased resistance to abrasion and tearing of hose rubber.

Under mechanical action on the cable sheath (crushing load), the strands of the electrically conductive threads and the ground core are closed through the inner electrically conductive rubber layer, as well as the instantaneous transfer of the impulse through the inner layer of the electrically conductive rubber sheath to the high-speed switching equipment for early disconnection of electrical equipment. Thus, due to the use of a two-layer inner sheath, consisting of a layer of electrically conductive rubber and a layer of hose rubber, it is ensured that the cable is disconnected in advance when subjected to a crushing external load.

The design of the cable in the proposed set of essential features has not been identified in the known sources of information, which confirms its novelty.

The drawing shows a cross-section of a power flexible shielded mine cable.

The cable contains three main 1 and one auxiliary 2 conductors, twisted from copper wires and covered with ethylene-propylene rubber insulation. A shield made of electrically conductive rubber is applied on top of the insulation. Uninsulated grounding conductor 3 is laid in the gap between the main conductors 1. The cable contains a profiled central core 4 and inter-core reinforcing bundles 5. The inner sheath 6 of the cable is made of two layers, and its inner layer is made of electrically conductive rubber, and the outer layer 7 is made of oil-resistant, flame-retardant hose rubber. The outer sheath 8 of the cable is made of oil-resistant with increased resistance to abrasion and tearing of hose rubber. Between the inner and outer shells 6 and 8 is a braid of strands twisted from electrically conductive threads 9.

Cable manufacturing does not cause difficulties for cable industry specialists. All materials used in the construction of the cable are known and commercially available in the industry. The cable is manufactured on the basis of well-known cable equipment and standard technologies. The manufacturing process includes such operations as drawing copper wire, twisting conductive conductors, applying rubber insulation, making a profiled core, general twisting of main shielded and auxiliary conductors, applying sheaths and braiding from strands twisted from electrically conductive threads, as well as electrical tests of insulated conductors. and cable ready-made. For these purposes, the following are used: wire drawing machines, braiding machines, stranding machines for stranding conductive conductors and general stranding, equipment for braiding, continuous vulcanization units, testing equipment. Main characteristics of the cable:

rated operating voltage - 1140 V

electrical insulation resistance of 1 km of cable - not less than 50 Ohm

electrical resistance of cable screens - not less than 1.5 Ohm

resistance of the cable to bends at an angle of ± π rad - 40,000 cycles

ambient temperature during cable operation - from -30 ° С to + 50 ° С;

long-term permissible temperature on current-carrying conductors - no more than + 75 ° С

minimum bending radius of cables - 200 mm.

Cables are flame retardant when laid alone.

The claimed power flexible shielded mine cable meets the criterion of "industrial applicability", since it can be repeatedly produced and used for its intended purpose with the achievement of the specified technical result.

Claims (1)

Power flexible shielded mine cable, containing three main and auxiliary conductive conductors, twisted from copper wires, each of which is covered with insulation from ethylene-propylene rubber, and a shield of electrically conductive rubber is imposed on top of the insulation, an uninsulated grounding conductor laid in the gap between the main conductors, a central core and inter-core reinforcing harnesses, inner and outer rubber shells, characterized in that between the inner and outer shells there is a braid of strands twisted from electrically conductive threads, while the inner shell is made of two layers, the inner layer of which is made of electrically conductive rubber, and the outer layer is made of oil-resistant flame retardant hose rubber, the outer sheath of the cable is made of oil-resistant hose rubber with increased resistance to abrasion and tearing.

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