【 Weak current College 】 elevator rope selection

1, Elevator rope selection

Steel wire rope by rope, wire and cord unit. Elevator rope is a single rope around the cord is a helical twisting. Usually 50-65, high-quality carbon steel or 60Si2Mn wire. For the sake of security, elevator ropes-steel wire, or 1, the wire diameter limits between 0.3 ~ 1.3mm. Commonly used elevator traction rope with West Lushi (X) and Ling Thom (W type). At present, the widespread use of domestic elevator lushi 8 or 6 West of steel wire ropes, one unit 8X (19) application.



1.1 wire rope mark recognition for example

The rated load of 1000kg to passenger elevator, for example, traction rope used 8X (19) — 16-140 right turn, with the number 8 for rope, lushi, X is West (19) for each of the wire rope, number 16-rope for nominal diameter (mm), 140-rope for tensile strength (kgf/mm2), the right hand for steel wire rope and rope in stocks in the rope, turn direction twisting. Homemade traction rope are right handed.

1.2 cord

Elevator rope are choosing impregnated with oil fiber cord, wire core support and fixed rope position resulting in improved contact between wire wire, slowing the impact load, play a role in oil storage tank for the long-term lubrication of wire rope, wire lubrication oil is good.

1.3 West Lushi (X) the structure and characteristics of the wire rope

Lushi elevator rope intersection West unit of cross-section per share of 1 + 9 + 9, i.e. the core plus tier one and tier-two consists of a total of 19 wires: Centre wire 1 m 1.2 m, f, the inner wire 9 root, 0.6 m f m, outer wire 9 root 1.05 m m f. Outer diameter than inner diameter, also known as the rough-and-steel wire rope. Its characteristic outer ① per share for the same quantity of steel wire, diameter and outer embedded within the inner notches, multiple layers of wire twisting is equal, not easy compact solid, open-book. Outer wear, increase in crude steel wire inner fine steel wire improve flexibility when bending, in favor of sliding, improving rope for flexible and service life. ② interlayer wire parallel lines contact fatigue resistance, wire rope, wire internal abrasion resistance between the good, the contact area increase, decrease of contact stress.

2, traction rope safety factor

From a security angle requirements of elevator rope has certain elements and GB7588 safety factor, have specific to K static: using three or three more traction rope for elevators, K static = 12; the use of two traction rope for elevators, K static = 16, often require passengers, cargo and the number of medical elevator rope should be not less than 4, the safety factor for 12; debris ladder should be not less than 2, the safety factor of 10.

Wire rope in static and dynamic in the work of two load, but affect the service life of the main wire rope or static load, in order to calculate the simplicity, only the static load for utility computing.

2.1 wire rope selection
In order to improve the elevator rope strength, long life, usually by-D/d ≥ 40 select elevator rope diameter, where d is the wire rope diameter not less than 8mm; D to traction wheel diameter;

2.2 safety factor calculation

-K static safety factor of elevator rope-;
SP-elevator rope tensile breaking;
M-elevator rope around the law determined by the ratio, 1: 1 m = when around method 1, 2: 1 round method m = 2;
Q — the rated load of the lift;
∑W—Wj+Wg+Wp
-Wi-cabin weight; Wg for the car is in the lowest layer cabin and traction wheel between the weight of steel wire ropes; Wp to balance rope tension load half (with balance compensation device).

3. use and maintenance of wire rope

3.1 rope for check

Elevator rope State direct relationships with equipment and passenger safety, must be sufficient attention to the careful observation and carefully check that the check: (1) check the number of broken wires, and twist away from the broken wires; (2) wirerope diameter varying light conditions, in addition to the Visual, updated regularly with Vernier caliper measurements rope diameter and wear; (3) check the elevator rope tension, the difference between the rope tension should not exceed 5%; (4) wire rope lubricant, clean and corrosion; (5) rope head and their combinations, full length with and without other abnormalities, such as rope exception elongation changes, etc.

3.2 rope wear and deformation

According to experience, the elevator rope in sudden fracture under normal condition of rare, its damage generally in long-running due to wear, and bending fatigue, corrosion or trauma evolved. Should pay particular attention to the wear and tear, corrosion examination. Wear including rope surface, stocks and shares, silk and silk wear between.

Mechanical wear mainly for external uniform wear, deformation and wear and three inner wear, as shown in Figure 2 (click here). A pure mechanical wear, generally speaking, the elevator rope in use because of its hardness than Groove wear high, very slow. But due to tension, Groove, steel wire ropes in the Groove skidding, wear, roll, and Groove abrasive, this wear under normal circumstances is uniform. B for deformation and wear, refers to the elevator rope in a period of wear, since the elevator rope and rope round often chronic shift or elevator rope pulley on violent vibration, shock, the elevator rope local extrusion; although the elevator wire cross section area did not decrease, but local extrusion Department of wire material has been compromised, easily broken wires. C-internal wear, since the elevator rope for frequent bending, unit wire between relative displacement, unit and unit contact pressure increase, so that the wire between adjacent units produce local indentation, over time will vary depending on the stress concentration and broken. As noted above, the elevator rope wear, small, will make the elevator rope steel wire cuttingArea smaller, lower their tension, serious should scrap replace elevator rope. As a rule of thumb, the elevator rope exist internal broken wires, Elevator rope running can hear "the sound of sentries".

3.3 rope lying in the Groove of

Check the Groove of working surface is smooth, elevator ropes lying in a Groove in depth. Method is a ruler along axis against traction wheel cylindrical surface, and then measuring the chute distance from the vertex to the ruler of wire rope. The gap reached 1.5mm, heavy cart or swap the wheel rim.

Inspection of elevator rope in the Groove bottom and inside is down, when the rope and skid base of gap decreased to 1mm when Groove back turning. Groove in the incision below the rim thickness, when the wire rope to 13 m f m f should be not less than 12.5 m m; when the wire rope to f 16 m m should be not less than 15.5 m m f.

3.4 elevator rope for corrosion

Elevator rope during use corrosion occurs, mechanical properties, wire diameter varying light, loose, so much so that between brittle fracture occurred. This fault is "avalanche" of fault, it's worse than a normal break or wear more dangerous. Maintenance where encounter particular attention should be paid to the wire rope rust should be carefully observed, such as the discovery of the corroded badly formed the Ma Hang or rope loose outer steel wire, wire or rope without thesis diameter thin numbers should be replaced; if it is discovered that the rope is "red oil", the cord-free, internal rust, needs attention, if necessary, cut rope head checking internal corrosion of steel wire ropes. Prevents corrosion of steel in the rope Oiler protection.

3.5 on analysis of broken wires

(1) overload and silk. Elevator rope withstand overload load or impact load, the fracture surface rendering shrinkable plastic cup, since the elevator rope safety factor, which breaking rare; (2) fatigue fracture. Appear in the unit of the bending program maximum side of the outer steel wire, metal fatigue fracture surface of broken wire, flat shape. (3) wear broken wires. Wire rope with traction wheel friction slippage between the cause, which breaking in wire wear extremely serious and occurs in the outer sides of the wire, the fracture surface was flat inclined stubble, fracture; (4) corrosion broken wires. Severe corrosion. Fracture is not tidy, assumes the solder tip; (5) cut off the wire. Be hard to pull off or a larger force combat, extrusion. Fracture is clipped; (6) kink broken wires. Such a break in the normal use is rare, occurring only when the rope causing kink relaxation. Fracture surface shape smooth, smooth.

3.6 rope for scrap replacement

Use the table to take the following points:

(1) wire surface did not suffer any damage, but broken wire elements to achieve the corresponding figures in the table should scrap; (2) wire surface wear or corrosion accounted for 30 per cent of diameter, even if the number is 0 broken wires should be scrapped; (3) surface wear percentage has been reached, and the corresponding number of broken wires are not scrap has not been reached; (4) Elevator steel cord appears broken shares should be scrapped; (5) Elevator steel wire rope for co-rotating twist around, its allowable number of elevator wire breakage as half of the values in the table; (6) the estimation of twisting distance: General to rope diameter for 6.5 times a twist, such as 8X (19) West Lushi rope 8 unit for PHI 16 mm twist from around 6.5 × 16mm = 100mm; (7) the elevator rope diameter reduction of 10% should be scrapped. (8) Elevator rope surface with serious corrosion, blackening, BLOB, Ma Hang and outer wire is loose, must be replaced immediately; (9) the replacement of the elevator rope, the same group of elevator rope along with replacement; (10) in use, if internal lubricant being squeezed out like sweating phenomenon, the elevator rope has reached overload status, this occurs to check now, find out why new shouldbe replaced when necessary; (11) Elevator rope for cleaning the surface of the sand, dirt, application of kerosene clean (no gasoline); (12) on the wire diameter of wire rope, broken wire number refers to the filament, a thick filament equivalent 1.7 thin wire.

3.7 rope lubrication

Generally speaking, in traction wheel diameter is large, the use of temperature in a dry place, rope 3 ~ 5 years itself still have sufficient lubricating oil, it is not necessary to add the new oil. But no matter how long, as long as the elevator rope rusty or drying found on signs, must be greased.

3.7.1 lubrication method

With A surface of the steel wire bristle brush against wire rope run direction uniform thin film a dedicated ET diluted type elevator wire rope grease or oil with 20, the benefits of this approach is simple, convenient without heating, coating, but should focus on pouring oil is not too much, rope surface energy slight infiltration of lubrication. Cannot smudge calcium base grease. B heating and coating. First wire brush to rope dirt and residue, and kerosene clear clean (no gasoline cleaning), lubricants (a mixture of graphite and vaseline) heated to 80 ° c above the coating. Wire rope lubrication to moderate, surface cannot compress oil too much. Otherwise, reduce drag gravitation, serious equilibrium doesn't load torque, elevator control, causing the elevator recoil, dun bottom accident; elevator rope in wheel slot skidding, like ING, severe wear Groove and rope itself.

3.7.2 run Parkour should possess characteristics

Without the acid and alkali, no water, no moisture absorption; difficult to dry in the atmosphere, temperature without hardening (cracking), high temperature without losses; appropriate viscosity in order to avoid the elevator rope run of oil leakage; have sufficient to seep into the elevator rope, wire strands and ropes core features.