What Is a Wire Rope Pulley?

A steel wire rope is a helical steel wire bundle that twists together steel wires that meet the requirements of mechanical properties and geometric dimensions in accordance with certain rules. The steel wire rope consists of a steel wire, a rope core, and grease. A steel wire rope is a rope that is first twisted into a plurality of layers of steel wire, and then a certain number of strands are twisted into a spiral rope around the core of the rope. In material handling machinery, it is used for lifting, traction, tensioning and carrying. The steel wire rope is high in strength, light in weight, stable in work, not easy to break suddenly, and reliable in work. In 1834, the European Orubt invented the world's first steel wire rope (smooth steel wire rope). The Tianjin First Steel Wire Rope Factory, established in 1939, was the first metal product enterprise in China.

The steel wire rope can be classified according to the material of the steel wire, the surface condition, the twisting method and the purpose of the steel wire rope.

In addition to round stocks, there are special stocks such as triangular stocks, oval stocks and flat stocks. From round

1. Steel wire rope can transmit long distance load.
2. Large load safety factor, safe and reliable use.
3. Light weight and easy to carry and transport.
4. Capable of withstanding various loads and variable loads.
5. It has high tensile strength, fatigue strength and impact toughness.
6. Under high-speed working conditions, wear resistance, shock resistance, and good running stability.
7. Good corrosion resistance, can work normally in the harsh environment of various harmful media.
8. Good softness, suitable for traction, pulling, strapping and other applications.

The steel wire is made of high-quality carbon steel, which can reach high strength after repeated cold drawing and heat treatment. Available in wet or open-air environments

There are three basic processes for wire rope production: drawing, twisting and closing.

Due to the unique properties of steel wire ropes, so far, no more ideal product has been found at home and abroad to replace steel wire ropes comprehensively or in a field. Therefore, steel wire ropes have become the fields of metallurgy, mining, oil and gas drilling, machinery, chemicals, aerospace and other fields. The quality of essential components or materials has also been concerned by many domestic industries, and a lot of manpower and material resources have been invested in wire rope use research and product development, and structural selection, daily use, maintenance and replacement of wire ropes Many procedures and rules were formulated during the process.

1. "Coal Mine Safety Regulations", "Safety Management Regulations for Hoisting Machinery", "Safety Regulations for Automobile Cranes and Tire Cranes", "Overhead Crane Safety Technical Inspection Details", etc., all of them are used for steel wire rope structure selection, daily use, maintenance and replacement Retirement and other aspects make practical provisions. 2. Coal and other industries include the inspection of steel wire ropes as the daily necessary safety production inspection management content. 3. Several research institutes have participated in the research of wire rope related projects and achieved results that can be transformed into productivity. 4. A batch of practical specifications for wire rope inspection and scrapping were effectively implemented. GB / T5972-2006 "Practical Code for Inspection and Scrap of Steel Wire Ropes for Cranes" replaces GB / T5972-1986 version of the standard, which was implemented on September 1, 2006. GB9075-1988 "Specifications for Inspection and Scrap of Wire Ropes for Aerial Ropeways" is applicable to single-line circulating, double-line circulating and reciprocating passenger and freight aerial ropes, but not applicable to temporary freight ropeways and forestry ropeways. The MT716-2005 coal mine important wire rope acceptance technical conditions and MT717-1997 coal mine vital wire rope energy measurement method and judgment rules are the legal basis for safe, correct and reasonable use of steel wire ropes in coal mines. 5. The Port Machinery Branch of the Chinese Society of Construction Machinery focuses on the research of steel wire ropes. Over the years, a lot of useful work has been done in the localization of steel wire ropes, scientific and reasonable selection and use.

1. Specific gravity. The wire rope diameter is the same, the heavier the specific gravity, the better the quality of the wire rope;

2. Steel wire rope core. The stronger the steel wire rope core, the heavier the specific gravity, the better the support for the outer strands of the steel wire rope, and the better the quality of the steel wire rope;

3. Materials. The material is steel grade and strength. The higher the steel number, the better the quality of the wire rope with higher strength;

4. After the rope is cut, the quality is slightly loose, and the quality of the wire rope with a relatively long twist length is better than that of a short twist length;

5. The corrosion resistance of 316 stainless steel wire rope is stronger than that of 306 stainless steel wire rope. 306 has better corrosion resistance than hot-dip galvanized steel wire rope. Hot-dip galvanized steel wire rope has better quality than galvanized steel wire rope. The quality of nylon coated steel wire rope is better than PE coated steel wire rope. Plastic steel wire rope has better quality than PVC coated steel wire rope, and plastic coated wire has better anti-corrosion ability than galvanized steel wire rope.

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(A) should be checked before use

Inspection scope: pull the wire rope for abrasion, rust, stretching, bending, deformation, fatigue, broken wire, exposed degree of rope core, and determine its safe lifting

Volume (including scrap).

(Two) maintenance matters needing attention

The use of wire rope

With the natural elongation of the traction wire rope, the force of each rope is different, and the tension deviation of each traction wire rope (generally 4 to 7) will exceed 5% and will be out of tolerance.

With the increase of running time of newly installed elevators, the steel wire rope will naturally stretch. In theory, the elongation of the traction wire rope is about 0.5%. For general low-rise elevators, the impact is not too great, but for high-rise elevators, especially elevators with a 2: 1 suspension, the impact cannot be ignored. For example: For a 15-storey passenger ladder, the length of the traction wire rope is about 50m. If it is suspended at 2: 1, the rope length is about 100m, and its 0.5% elongation is as much as 500mm. We know that the buffer distance of the hydraulic buffer is 200-350mm, and the buffer distance of the spring buffer is 150-400mm. With the natural elongation of the traction wire rope, the leveling accuracy will change. Some elevators can automatically relevel the level, while most elevators require the maintenance worker to adjust the leveling accuracy so that it meets the GBl0060-93 leveling accuracy. In this way, the elongation of the traction wire rope must be fully extended to the counterweight side, causing the buffer distance on the counterweight side to become smaller and smaller. In the end, the buffer distance may be too small and the tolerance may be excessive. Before the elevator is leveled, the counterweight has been loaded on the buffer, causing an elevator failure.

Handling opinions:

During installation, the buffer distance on the counterweight side should be as close as possible to the upper limit. Once the traction wire rope is extended, it can be compensated by itself;

During installation, the adjustment nut of the traction wire rope head plate should have an adjustment margin of about 100mm for the maintenance worker to adjust;

The counterweight base should be provided with 3 adjustment blocks (each adjustment block is about 120mm high). When the buffer distance becomes small, the maintenance worker can remove 1-3 adjustment blocks according to the situation;

If there is no adjustment block on the counterweight base and the adjustment nut of the rope head board cannot be adjusted, then you have to cut the wire rope and redo the rope head (can be replaced one by one without lifting the car or supporting the counterweight).

Treatment opinion: The maintenance worker stood at the top of the car at the height of 2/3 of the hoistway and measured the tension of each rope with a spring, and adjusted the nut of the rope head plate so that the deviation of the tension did not exceed 5%.

The speed governor wire rope will also naturally stretch under the action of the weight of the speed governor tensioning device. In severe cases, the speed limiter loose rope switch may malfunction, making the elevator unable to run.

Handling suggestions: Re-tie the governor wire rope to meet the requirements, and restore the slack rope switch to the normal position.

With the natural elongation of the traction wire rope, the Guizhou Guiyang elevator with the compensation chain (rope) may cause the compensation chain (rope) to mop the floor, bring unnecessary noise, and even severely damage the compensation chain (rope) support and Damage to other parts in the hoistway.

Disposal advice: The maintenance worker should be diligent in checking and find that the compensation chain (rope) is to be tied up again to make it meet the requirements.

Wire rope terminology

GB870688

This standard applies to steel wire rope products and the terms commonly used in the standard. In the production and repair of steel wire rope product standards and practical applications, the terms specified in this standard shall be used.

This standard is equivalent to the international standard ISO2532-74 "Wire Rope-Vocabulary".

In a steel wire rope, the steel wires and the layers of the layers are arranged in a manner that minimizes the torque or the degree of rotation. For example, multiple layers of steel wires with the same structure constitute multiple wires and a single-layer wire rope twisted around an independent steel wire core. When the twisting directions of the steel wire and the strands of the layers are opposite, the steel wire rope has lower torsional stress, and thus exhibits non-rotation or micro-rotation.

1. Phosphate-coated steel wire rope (Chinese patent). The weight of the phosphating film of the rope is 3-60 g / m2. After the phosphating, the steel wire is not cold-drawn before being twisted. It is directly twisted into the strand, steel core and wire rope. .

2. Galvanized steel wire rope, including hot-dip galvanizing and electro-galvanizing. The thicker the galvanized layer is, the stronger the anti-corrosion ability is.

3. Plastic coated steel wire rope, coated with a certain thickness of plastic on the outer surface of the wire rope or the outer surface of the strand, including polyethylene, polypropylene, polyurethane, etc.

4. Smooth steel wire rope, rope made from heat-treated and cold-drawn raw materials prepared on the surface (note: the phosphating film formed during the pre-treatment process gradually falls away from the wire drawing die during cold drawing), and the wire is no longer After any surface treatment, directly twisted strands, steel cores and steel wire ropes, production began in foreign countries in 1834, and domestic first steel wire rope factory in Tianjin in 1939.