SU1775735A1 - Power flexible screened cable - Google Patents

Description

The invention relates to electrical engineering. in particular to cable technology.

Based on the positive foreign and domestic experience in using self-propelled pneumatic-wheel cars with electric drive in potash mines, the scope of their application is expanding. In particular, self-propelled wagons are introduced in coal mines, including hazardous gas, dust and sudden emissions.

The operating conditions of the cars impose the basic requirements on the cables - to have high mechanical strength with multiple windings-windings at the receiving drum, withstand multiple bends around rollers with a diameter of 400 mm with tensile forces: permanent - 100 kG, short-term (jerking) up to 500 kG. Cables must be torsion resistant.

In the domestic industry, similar cables that satisfy these requirements are not available.

Known electrical cable designed for winding on a drum. The cable is characterized in that, in order to increase torsion resistance, fiberglass is vulcanized into the cable sheath.

This design partially solves the problem - it provides sheath strength and cable torsional stability without increasing cable tensile strength. The disadvantage of this design is also the low resistance of the cable to bending, due to the known fragility of fiberglass.

The closest to the achieved positive effect and technical essence is the flexible power cable of the KGEShU brand, manufactured according to TU

16.K73.012-89. The cable consists of three power conductors, on top of the insulation of which conductive shields are superimposed: groups of insulated auxiliary conductors in a common elastic conductive shielding

1775735 A1 no. Power shielded and a group of auxiliary cores are twisted around an uninsulated ground conductor, with four reinforcing plaits made of strong synthetic fibers between the cores. On top of twisted cores, a two-layer sheath is applied, hardened between the layers of threads in the form of a 2-sided winding or braid. The outer and inner layers have a spline connection between each other. The disadvantage of this cable is the low mechanical resistance of the cable to forced bending under the action of a large tensile load.

The aim of the invention is to increase the operational reliability of the cable by improving the mechanical characteristics.

This goal is achieved by the fact that in a cable containing insulated conductors, a grounding conductor, insulated auxiliary conductors, a two-layer polymer sheath with double-sided winding, the threads are made of synthetic material with a relative elongation of not more than 3% and a density of 58.8 tex, and the laying angle winding lies in the range of 48 ... 60 degrees.

The winding imposed in this way plays the role of hardening the shell and at the same time allows it to withstand large tensile forces in conditions of forced bending.

The drawing shows a cross section of a power cable. The cable contains three power copper conductors for a voltage of 1140 V (1), coated with rubber insulation (2) and a shield (3) made of elastic conductive rubber: a group of 3 auxiliary, rubber-insulated conductors for a voltage of 220 V and covered with a common shield made of conductive rubber; power and a group of auxiliary cores are twisted in a cord around an uninsulated ground conductor (5). The cable sheath is two-layer (6), with a spline connection between the layers. Between the outer and inner layers of the shell is a winding of high-strength synthetic threads (7).

An example of a specific implementation 1; a cable sample was made with a cross-section of 3x16 + 1x10 + 3x2.5 mm ² . The cable contains three copper conductive conductors with a cross section of 16 mm ² for a voltage of 1140 V insulated with EPTI-45 rubber 2.0 mm thick and a screen made of rubber EPI-30 with a thickness of 0.5 mm, three auxiliary copper conductors with a cross section of 2.5 mm ² for voltage 220 B, insulated with rubber ТСШМ-38 with a thickness of 1.0 mm and twisted into a group. The group of twisted auxiliary cores is covered with a common elastic screen made of EPSh30 rubber 1.0 mm thick; power and a group of auxiliary conductors are twisted in a cord around an uninsulated ground conductor. According to the general twist of the cores, an inner layer of a shell made of ShN-40 rubber is applied.

1.5 mm. A 2-sided winding at an angle of 54 ° was applied on top of the inner shell by strands twisted from synthetic NSWM threads with a density of 58.8 tex with a relative elongation of not more than 3%. Over the winding, an outer layer of a shell of 2.0 mm thickness from I1IH-50 rubber is applied.

The results of laboratory tests are satisfactory, the destruction of conductive conductors does not exceed 3%.

An example of a specific implementation 2. A cable with a cross-section of 3x16 + 1x10 + 3x2.5 mm ^{2 of a} similar design with a winding made of the same threads at an angle of 70 ° was manufactured. The results of the tests showed a large percentage of destruction of conductive conductors, the ground conductor is destroyed by 100%. At the same time, cables were made with a cross section of the main strands of 16 mm ^{2 of a} similar design, but with a winding made of polyester technical threads with a density of 590 tex, having a large (16%) relative elongation compared to a NSVM thread, with a winding made at an angle of 52 °. Tests show a negative result.

For testing, cable samples were made with a winding from NSVM threads and imposed at a winding angle of 48 °, 60 °.

The test result showed that the destruction of conductive wires is an average of 5-6%.

The manufacture of cables for all operations is carried out on standard technological equipment according to standard technological processes.

As a winding material, high-modulus technical NSVM threads GOST 28007-88 can be used.

In comparison with the prototype, the advantages of the invention are as follows;

- longer cable service life;

- increases the reliability of the power cable to mechanical deformation.

Claims (1)

Claim Power flexible shielded cable containing insulated conductive conductors, ground conductors, insulated auxiliary conductors, two-layer polymer sheath with double-sided winding with threads between the layers. characterized in that. in order to increase operational reliability by improving mechanical characteristics, the threads are made of synthetic material with a relative elongation of not more than 3% and a density of 58.8 tex, and the angle of application of the winding is in the range 48 ... 60 °. /