METAL SHEATHED CABLE DESIGNED ON THE BASIS OF TORQUE BALANCE AND DESIGN METHOD THEREOF

Abstract

A metal sheathed cable includes an optical unit and a control unit helically twisted together, a grounding wire unit distributed in the gaps between the optical unit and the control unit to form an inner layer cable core, a filler watertightly filled into gaps among the optical unit, the control unit and the grounding wire unit, and a taped covering arranged outside the inner layer cable core; a power unit and a filling core helically twisted around the inner layer cable core, the grounding wire unit distributed in the gap between the power unit and the filling core, the filler watertightly filled into gaps among the power unit, the grounding wire unit and the filling core, and the taped covering arranged outside the outer layer cable core; an inner protective layer wrapped outside the outer layer core, and a sheathing layer twisted outside the inner protective layer.

Claims

1. A metal sheathed cable designed on the basis of torque balance, comprising: an optical unit, a control unit, a power unit, a grounding wire unit, a filling core, a taped covering layer, a watertight filler, an inner protective layer and a sheathing layer, wherein the optical unit and the control unit are helically twisted together, the grounding wire unit are distributed in gaps between the optical unit and the control unit to form an inner layer cable core, the filler is watertightly filled into the gap among the optical unit, the control unit and the grounding wire unit of the inner layer cable core, and a taped covering is arranged outside the inner layer cable core; the power unit and the filling core are helically twisted around the inner layer cable core, the grounding wire unit are distributed in the gap between the power unit and the filling core to form an outer layer cable core, the filler is watertightly filled into the gaps among the power unit, the grounding wire unit and the filling core of the outer layer cable core, and a taped covering is arranged outside the outer layer cable core; an inner protective layer is wrapped outside the outer layer core, and a sheathing layers is twisted outside the inner protective layer, the sheathing layer adopts the design method of torque balance.

2. The metal sheathed cable designed on the basis of torque balance according to claim 1, wherein the design method of torque balance for the metal sheathed cable is as follows: $T=\frac{P*D}{2}$ $\sin .Math..Math.=\frac{P}{W}$ $E=\frac{\frac{W}{A}}{\mathrm{.Math.}}$ $P=E*A*\mathrm{.Math.}*\sin .Math..Math.$ $T=\frac{E*A*\mathrm{.Math.}*D*\sin .Math..Math.}{2}$ $.Math.T=\frac{N*E*A*\mathrm{.Math.}*D*\sin .Math..Math.}{2}$ $R_T=\frac{.Math.T_o}{.Math.T_i}=\frac{N_o*E_0*A_0*{\mathrm{.Math.}}_0*D_0*\sin .Math..Math.{}_0}{N_i*E_i*A_i*{\mathrm{.Math.}}_i*D_i*\sin .Math..Math.{}_i}$ E of the inner steel wire is the same as E of the outer steel wire, then $R_T=\frac{N_o*A_0*D_o*\sin .Math..Math.{}_0}{N_i*A_i*D_i*\sin .Math..Math.{}_i}$ $A=\frac{}{4}.Math.d^2$ $R_T=\frac{N_o*d_o^2*D_o*\sin .Math..Math.{}_0}{N_i*d_i^2*D_i*\sin .Math..Math.{}_i}$ in which, Aarea of the single steel wire; ddiameter of the steel wire; Dpitch diameter of the sheathing layer; Eelastic modulus of the steel wire; Nnumbers of the single steel wire; Pcircumferential force of the steel wire; RTtorque coefficient; Ttorque; Wtensile strength of the steel wire; stranding angle of the steel wire; strain of the steel wire; oouter steel; iinner steel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 is a structure diagram of the invention;

[0024] In the FIG. 1optical unit, 2control unit, 3power unit, 4grounding wire unit, 5filling core, 6taped covering, 7watertight filler, 8inner protective layer, 9sheathing layer;

[0025] FIG. 2 is a schematic view of the steel wire torque of the invention;

[0026] FIG. 3 is a schematic view of the steel wire circumferential force of the invention;

[0027] FIG. 4 is a schematic view of the steel wire stranding angle of the invention.

DETAILED DESCRIPTION

[0028] The invention will be further described in combination with embodiments.

Embodiments

[0029] As shown in FIG. 1, a metal sheathed cable designed on the basis of torque balance, comprising an optical unit 1, a control unit 2, a power unit 3, a grounding wire unit 4, a filling core 5, a taped covering 6, a watertight filler 7, an inner protective layer 8 and a sheathing layer 9.

[0030] The optical unit 1 and the control unit 2 are helically twisted together, a grounding wire unit 4 is distributed in gaps between the optical unit 1 and the control unit 2 to form an inner layer cable core, a filler 7 is watertightly filled into the gap among the optical unit 1, the control unit 2 and the grounding wire unit 4 of the inner layer cable core, and a taped covering 6 is arranged outside the inner layer cable core; the power unit 3 and the filling core 5 are helically twisted around the inner layer cable core, the grounding wire unit 4 is distributed in the gap between the power unit 3 and the filling core 5 to form an outer layer cable core, the filler 4 is watertightly filled into the gaps among the power unit 3, the grounding wire unit 4 and the filling core 5 of the outer layer cable core, and a taped covering 6 is arranged outside the outer layer cable core; an inner protective layer 8 is wrapped outside the outer layer core, and the sheathing layers 9 is twisted outside the inner protective layer 8.

[0031] The sheathing layer 9 is twisted counterclockwise by two-layer ultra-high tensile galvanized steel wires, wherein the design method of the torque balance design method is:

[0032] According to FIG. 2:

[00004]$T=\frac{P*D}{2}$

[0033] According to FIG. 3 and FIG. 4:

[00005]$\sin .Math..Math.=\frac{P}{W}$$E=\frac{\frac{W}{A}}{\mathrm{.Math.}}$
P=E*A**sin

[00006]$T=\frac{E*A*\mathrm{.Math.}*D*\sin .Math..Math.}{2}$$.Math.T=\frac{N*E*A*\mathrm{.Math.}*D*\sin .Math..Math.}{2}$$R_T=\frac{.Math.T_o}{.Math.T_i}=\frac{N_o*E_0*A_0*{\mathrm{.Math.}}_0*D_0*\sin .Math..Math.{}_0}{N_i*E_i*A_i*{\mathrm{.Math.}}_i*D_i*\sin .Math..Math.{}_i}$

[0034] E of the inner steel wire is the same as of the outer steel wire, then

[00007]$R_T=\frac{N_o*A_0*D_o*\sin .Math..Math.{}_0}{N_i*A_i*D_i*\sin .Math..Math.{}_i}$$A=\frac{}{4}.Math.d^2$$R_T=\frac{N_o*d_o^2*D_o*\sin .Math..Math.{}_0}{N_i*d_i^2*D_i*\sin .Math..Math.{}_i}$

[0035] in which, Aarea of the single steel wire;

[0036] ddiameter of the steel wire;

[0037] Dpitch diameter of the sheathing layer;

[0038] Eelastic modulus of the steel wire;

[0039] Nnumbers of the single steel wire;

[0040] Pcircumferential force of the steel wire;

[0041] RTtorque coefficient;

[0042] Ttorque;

[0043] Wtensile strength of the steel wire;

[0044] stranding angle of the steel wire;

[0045] strain of the steel wire;

[0046] oouter steel;

[0047] iinner steel.

[0048] By adopting the above design method of torque balance, the problem of the torque deviation existing between layers inside a steel wire sheathing layer of a metal sheathed cable at the structural design level can be solved, thereby guaranteeing that the metal sheathed cable does not rotate when bearing a working load.