Introduction of manual chain hoist

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The manual chain hoist is a kind of lever hoist, also known as the inverted chain, which is a kind of manual lifting tool, which is a heavy-duty operation level. The Chain Hoist is a lifting tool that is driven by human power through the handle to drive the movement of the retrieval equipment. It is compact in structure, convenient to carry, and easy to operate. It is suitable for lifting and towing operations in remote areas and outdoors, and the distance between raising and towing is not restricted, which can be determined by the length of the selected chain.

manual chain hoist

Causes and repairs of the wear and tear of electric hoist transmission gears

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  1. If there is wear caused by impurities in the lubricating oil, it is generally called abrasive wear. This kind of wear often has deep scraping tracks on the tooth tops and roots. The scraping tracks are perpendicular to the pitch line and parallel to each other. After the scratching occurs, the oil temperature in the reducer rises, and the gear transmission produces sharp noises. At this time, the lubricant must be replaced.
  2. Due to the deviation of the tooth profile and the excessive deviation of the installation center distance, it may cause excessive extrusion of the tooth tip edge and the tooth root transition curve of the gear pair, causing severe wear on the tooth root fillet. Due to the overload of the electric hoist, the tooth root of the driving wheel or the tooth top of the driven wheel is often worn off by a very thin layer.After the gears of the hoisting mechanism reducer are worn, the tooth thickness should not be less than the original tooth thickness. For the gears of the running mechanism, the tooth thickness should not be less than the original tooth thickness. If the gear exceeds the standard, a new gear should be replaced. The abrasion of the tooth thickness of the electric hoist can be checked by measuring the thickness of the indexing circle with a measuring caliper.

What problems should be paid attention to in the use of electric wire rope hoist?

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The wire rope electric hoist may produce many urgent events in the process of use, and it needs to be stopped urgently, otherwise risk accidents may occur.

Wire rope cracking: The wire rope cracking will cause a risk of goods falling, and will also threaten people’s lives and property safety in severe cases.
Severe trajectory deformation: severe trajectory deformation will cause the wire rope electric hoist to violate the trajectory during operation, or even drop directly.

Drum cracks: Drum cracks will cause more parts to be damaged if they continue to work, and the electric hoist will be damaged when severe
Motor fault: The motor is the core component of the electric hoist. If something goes wrong, stop the machine urgently to prevent the motor from burning out.

Overload application: If the wire rope electric hoist is found to be overloaded during operation, it should be stopped immediately. Overloading will lead to a reduction in the service life of the electric hoist.

Lifting weight refers to the weight that the electric Wire Rope Hoist can lift. It has a lot to do with the practical quality of suspended or moving objects. In general, the lifting weight should be greater than or equal to the actual weight of the object to be lifted. Since the electric hoist is used under full load and overload for a long time, its service life will be relatively shortened. It is recommended to choose a larger one. The correct selection of the lifting weight is related to the safety of its subsequent use. It is better to choose more large tonnage than small tonnage.

Lifting height refers to the interval between the upper and lower limit positions of the lifting machinery reclaimer. Generally speaking, it is closely related to the needs of customers and is selected according to the spatial height of the place of use. If the lift is too short, it will cause the lower hook to reach the position of the object to be lifted and cannot be used. Lifting weight and lifting height are two very important parameters, which also need to be reminded. After purchasing a wire rope electric hoist, check whether there is a sign on the label, whether there are relevant instructions such as lifting weight, lifting height, and manufacturer.

 

Features of European type bridge crane

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European-style bridge crane, European-style crane adopts a unique design concept, has the characteristics of small size, light weight, and small wheel pressure.

Compared with traditional cranes, the limit distance from the hook to the wall is the smallest and the headroom is the lowest. The European-style crane can work closer to the front and has a higher lifting height, which actually increases the effective working space of the existing plant. Because the crane has the characteristics of light weight and low wheel pressure, the new workshop space can be designed to be smaller and more complete. Smaller plant means that the initial construction investment and long-term heating, air conditioning and other maintenance costs can save a considerable amount

Analysis of Causes to Fatigue of Lifting Wire Rope

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Fatigue

Steel wire ropes are mainly subjected to bending fatigue and fatigue caused by stretching, twisting, and vibration during use.

Bending fatigue

The steel wire rope is repeatedly flexed up and down in the pulley or drum. Numerous bends can easily cause the steel wire to fatigue, reduce its toughness, and ultimately lead to wire breakage. The fatigue broken wire appears on the outer wire on the side of the strand with the most bending degree. Under normal circumstances, the appearance of fatigue broken wire means that the wire rope is near the end of its use.

Fatigue caused by stretching, twisting and vibration

During the start and end of the crane wire rope, and before and after the bundled wire rope bears the load, the changing tensile stress will cause metal fatigue. In addition, the steel wire rope is often subjected to torsion and vibration, which is also the cause of fatigue.

The principle of fatigue damage is that under the action of variable stress, the surface of the thin steel wire first forms an initial crack due to various slippages, and then the crack tip is repeatedly plastically deformed under the action of shear stress, so that the crack propagates until it breaks. The broken wires caused by fatigue are generally flat, and most of them appear on the surface steel wire, and they are very regular.

How to Maintain the Explosion-proof Electric Hoist?

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First of all, in terms of appearance and material, if the operator pays more attention to maintenance, the explosion-proof electric hoist that has been used for a long time is still intact and looks very new.
Secondly, if the parts are checked regularly, the dust is cleaned up and the lubricant is added in time, the efficiency will be greatly improved and the frequency of maintenance will be reduced.

  1. Check whether the walking and lifting are flexible and reliable. The direction of the button is consistent with the direction of the explosion-proof electric hoist and the sound will be normal.
  2. Check whether the wire rope is fastened and whether the rope guide is installed with safety regulations.
  3. Check the braking situation, whether the nut behind the motor is loose, and whether the braking is very sensitive.
  4. Check the lubrication and check whether the lubrication point is well lubricated (lubricated parts include: lifting reducer, walking reducer, rolling bearing).
  5. The explosion-proof electric hoist wire rope is seriously worn and should be scrapped. The fuel should be changed according to the actual situation.

Electric Hoist Fault Treatment

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electric hoist is a kind of special lifting equipment, installed on overhead cranes and gantry cranes. The electric hoist has the characteristics of small size, light weight, simple operation and convenient use. It is used in industrial and mining enterprises, storage, docks and other places.

Electric hoist fault treatment

  1. After starting, the motor does not rotate and heavy objects cannot be lifted
  • Excessive overloading, overloading is not allowed
  • The voltage is more than 10% lower than the rated voltage, wait for the voltage to return to normal
  • The electrical appliance is faulty, the wire is disconnected or the contact is poor, and the electrical appliance and the line are repaired.
  • The brake wheel and the rear end cover are seized by corrosion, and the brake wheel cannot be separated. Remove the brake wheel and clean the corroded surface
  • Sweep the bore of the motor, and deal with it according to the fault number 9
  • The wire is too thin, replace the wire

2. The braking is unreliable, and the sliding distance exceeds the specified requirements

  • Due to the large wear of the brake ring or other reasons, the spring pressure is reduced and the spring pressure is adjusted
  • The brake ring is in poor contact with the cone surface of the back end cover, remove it for grinding
  • The brake surface has oil stains, remove it and clean it
  • The brake ring is loose, replace the brake ring
  • Pressure spring fatigue, replace the spring
  • The coupling is not working well or stuck, check its connection part

The amount of movement of the cone rotor is too large, adjust according to the regulations

Causes of Damage and Fracture of Crane Hooks and Preventive Measures

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The hook is the most used lifting device for cranes. It bears all the loads of lifting. During use, once the hook is damaged and broken, it may cause major accidents.

The cause of the damage and fracture of the hook is that the hook is cracked, deformed, and damaged due to friction and overload.

In order to prevent the hook from malfunctioning, overload lifting is strictly prohibited during use. During the inspection, attention should be paid to the opening of the hook and the wear of the dangerous section. At the same time, the hook should be annealed regularly. If cracks are found, they should be scrapped in accordance with the requirements, and the hook must not be repaired by welding.

Main Points of European Type Crane Installation

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European-style crane electric hoist is generally equipped with the main beam. Since the electric hoist is not hoisted under the main beam as a whole, it is particularly difficult for the electric hoist equipment under the main beam. Assuming that the truck crane is used alone, it is difficult to equip the electric hoist. The difficulty of the equipment is that the center line, the lifting point line of the European crane and the center line of the main beam are all in a vertical plane. It is almost impossible for the truck crane to send the electric hoist to the required position, so there is a certain degree of difficulty in the equipment process.

The self-weight of the European standard bridge crane is much lighter than the traditional crane, and the transmission efficiency is high. The European standard bridge crane eliminates many of the above-mentioned transmission components, and selects better-performing materials to manufacture various key components, which greatly reduces the volume and weight of each arrangement, and then reduces the burden of the whole machine. The primary load-bearing component can naturally reduce the cross-section and weight. According to the above fundamental power formula, when the force is small, the power naturally decreases.

Users who have used domestic traditional cranes and European standard bridge cranes may find that the motor power of each arrangement of European standard bridge cranes is smaller than that of traditional cranes with the same tonnage and span. Although the power of the European standard bridge crane is small, it does not affect the operation. Assuming that the power of the traditional crane is configured according to the European power, it will show the shortcomings of the motor and even burn the motor.

When the electric hoist is equipped separately, the crane manufacturer generally uses two chain hoists to lift from both sides of the main beam. When the height of the main beam box is satisfied with the lifting space, two lifting straps can be used to form two lifting points around the main beam. Hang the Chain Hoist on two lifting points, and then hoist the electric hoist by hand. Since the two chain hoists are hoisted together, pay attention to the balance of the electric hoist during the hoisting process. After hoisting to the required height, the equipment and fixing can be carried out.

Single Beam Crane Buffer Function

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Those who understand the installation method and process of a single beam crane may know that the buffer is not used in normal operation. Since the limit switch will be installed in the travel limit position of the large and small vehicles, when the single-beam crane reaches the limit position, the travel switch will act, and the crane will stop before colliding with the safety stop. But the buffer is also an indispensable part, the first consideration is to improve the safety of the whole machine. When the travel limit switch fails, the buffer should ensure that when the single-beam crane collides with the end stop at normal speed, it can absorb enough energy to ensure the safety of the crane.

At present, most of the buffers used on bridges and gantry cranes are rubber buffers and polyurethane foam buffers. The rubber buffer is composed of all rubber or multiple rubber plates, with a simple structure and low manufacturing cost. When a collision occurs, the kinetic energy of the crane is mainly consumed by its own internal friction. Generally used when the crane’s operating speed does not exceed 50M/min.

Polyurethane foam buffer has the advantages of large energy absorption, good cushioning performance, oil resistance, aging resistance, acid resistance, corrosion resistance, high temperature and low temperature resistance, insulation and explosion-proof, low density, light weight, simple structure, low price, no noise, no sparks, etc. The device is convenient to protect and has the characteristics of long service life. Therefore, it has been widely used worldwide. In general cranes, it can replace rubber and spring buffers, and it is more worthy of promotion in explosion-proof places.