What advantages does the girder launcher crane show in use?

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Bridge girder launcher crane is short for bridge erecting machine. The advantage of gantry type rigid frame is outstanding. Lightweight structure, good wind resistance. In order to save labor, this method is often used in bridge construction. The bridge erection machine is composed of gantry, hoist trolley, trolley running mechanism, driver’s cab and electrical control system. The portal frame is a truss structure, including main beam, upper beam, supporting leg, lower beam, trolley, railing, etc.
The supporting tools of the bridge erection beam launcher machine are two supports, which can be used normally without too large an area. Adaptable and can be used in many situations. The bridge girder launcher crane is actually an extension of the bridge crane. Although the appearance is different, it is very convenient to lift heavy objects, reducing the cost and time.
If you have an outdoor yard and need to load and unload cargo, you can also use a bridge builder. Operation scope can meet your needs and complete tasks faster.
Launcher girder crane is a kind of lifting equipment used in loading and unloading operations. The hook is an important part of the lifting mechanism and falling object of the bridge erection machine. Once the hook appears the problem, will cause the suspension to fall, has the serious accident. Today, let’s take a quick look at what caused the hook hanger to fall.
The design is not standard, such as overload protection failure, balance wheel, shaft strength is not enough, no anti-decoupling device, sling, rope selection is not reasonable, otherwise it can not be replaced in time, lack of necessary safety protection, maintenance is not in place. Abnormal operation, resulting in loss of control of movement, damage to parts or structures, abnormal safety. The detection of environmental factors such as high dust, high temperature, high humidity, low temperature, high noise, windy days and poor lighting will distract people’s attention, directly affect workers’ reactivity and technical stability, increase the probability of misoperation and reduce work efficiency. Improper operation caused the accident.
Including safety awareness levels; Implement crane management, inspection and regular safety performance inspection; Conduct safety education and training for relevant personnel; Conduct special training for crane operators, formulate crane safety operation rules and regulations; Establish reward and punishment system for violation of regulations, emergency plan for accidents, normal use of hoisting equipment and hoisting accessories. Inspection lack of effective monitoring and management. Any negligence or inadequacy in safety management is an important cause of the casualties of bridge erecting launcher cranes.

Advantages of chain hoist over wire rope hoist

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Chain Hoist is smaller than Wire Rope Hoist. Because the chain hoist adopts sprocket and chain lifting, the width of the sprocket need only reach 1.6 times of the chain. The wire rope hoist needs to wind the wire rope on the drum, and keep two to three turns on the drum.
Under the condition of the same track height, the hoisting height of the chain hoist is high. For electric wire rope hoist, the wire rope is wound on the drum, the inner side of the wire rope is compressed and the outer side is pulled, so the diameter of the drum must not be too small, more than 20 times the diameter of the wire rope, to ensure that the stress on the wire rope does not exceed the allowable stress. The chain wheel diameter of the chain hoist is not compulsory. Relatively speaking, it can be made much smaller than the wire rope drum of the same tonnage.
The chain hoist has a small running limit. The drums of electric wire rope hoists are generally arranged along the running track of the hoist, occupying a large space. The chain hoist sprocket can be arranged perpendicular to the track, and the size of the sprocket itself is smaller than the size of the drum. In this way, the effective distance that the chain hoist can reach is significantly larger than that of the wire rope hoist.
When the chain hoist is raised, the hook has no horizontal displacement. When the chain hoist is raised, the chain passes the sprocket to achieve the effect of straight up and down. Most wire rope hoists below 5t are single-out rope type. When the hook is up and down, the hook also moves left and right along the direction of the drum due to the left and right movement of the wire rope on the drum.

 

 

Electric hoist

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The electric hoist has full speed control, and the operator can fully control the lifting speed. Electronic shifting technology eliminates the effects of positioning the workpiece and eliminates downtime. The lower speed allows the workpiece to be lowered slowly for a soft stop, thereby extending the life of the gear train components, load chain hooks and brake components. Weight overload protection prevents lifting above the rated lifting capacity. Thermal overload protection prevents the motor from overheating at low voltages.
Electric hoists affect their working life in many ways, including design, production, use and maintenance. Due to the higher price, minimizing the number of replacements and repairs can effectively save costs and reduce losses in many ways.
The electric hoist is reasonably designed to meet specific conditions. It meets different requirements in terms of lifting weight, lifting height, power and voltage, etc. It is easy to operate, improves work efficiency and extends service life. Utilizing new materials, while ensuring product durability, strict control of raw materials, processes, quality inspection and other processes to prevent unqualified electric hoists from entering the market. Install and use according to working conditions, maintenance and repair are in place, use special specifications electric hoist for special conditions.
In the process of using electric hoist, various abnormal situations often exist. Usually, someone who knows a little bit will rule out which component is faulty based on sound and malfunction. Failures include failures of the reducer and brake. Let me introduce you specifically. Common accidents of the reducer include leakage of parts and local heat of parts.
The oil leakage was mainly caused by the deformation of the box, the failure of the sealing gasket, the smooth contour, and the tightness of the bolts. In the oil leakage part, including the surface layer connecting the bearing end cover and the housing, for various reasons, the bolt can be appropriately strengthened or replaced by a washer.
The local heat of the reducer is mainly caused by bearing damage, journal jamming, and system tooth damage. Lubricant is indeed added and added. If the gearbox is hot, determine the housing of the reducer, especially the bearings. If the whole is hot, it is because a lot of oil has been added, and the holes in the reducer should be checked to release excess oil. If the bearing is hot, the oil level should be opened to identify the bolt holes and check for escaping oil. If there is not a large amount of oil flowing out, the total amount is appropriate.
Common brake failures include brake failures and large total slip. Typically, the spacing of the brake fittings usually exceeds 80 mm. Inspect the joint surface and find excessive wear. In this case, the screws of the brake can be released and the fan gear can be removed. Remove oily stains from the surface, and adjust the nut slightly to obtain a more suitable distance. If the spring is prone to fatigue, it should be replaced. If the brake ring is damaged, it is difficult to ensure the interval and replace the brake ring. Replace the internal accessories and apply a small amount of water to the added brake ring for a smooth installation. Another type of failure is when the brake is difficult to open when the electric hoist is activated. This is because the setting interval is small or the back cover is rusted. At this point, you can fine-tune the nuts to lock them, add space to each other, or remove the back cover and continue cleaning.
After using the electric hoist for a period of time, the gears will wear out. What are the factors that cause the wear? Another form of failure of the drive gear on electric hoists is wear and tear, and the teeth become thinner after wear. If wear is caused by impurities in the lubricating oil, it is often referred to as wear. This wear usually has deep scraping at the top and root of the teeth, which is perpendicular to the pitch line and parallel to each other. After the scraping path occurs, the oil temperature in the reducer rises and the gear transmission makes a slight noise. In this case, the lubricant must be replaced.
Due to the deviation of the tooth shape of the electric hoist and the deviation of the installation center distance, the edge of the gear tooth tip and the transition curve portion of the root may be excessively squeezed, so that the root radius of the tooth root is seriously worn. Due to the overload, the root of the driving wheel or the top of the driven wheel (sometimes the entire tooth surface) is often worn by a thin layer.

Main characteristics of gantry crane

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gantry crane is a variant of bridge crane, also called gantry crane. It is mainly used for loading and unloading of outdoor cargo yard, storage yard cargo and bulk cargo. The gantry crane has the characteristics of high site utilization, large operating range, wide adaptability and strong versatility, and is widely used in port cargo yards.
Its metal structure resembles a door-shaped frame. Two feet are installed under the main beam, which can directly walk on the ground track. The main beam can have outriggers at both ends.

1.Main beam structure
Single Girder Gantry Cranes and double girder gantry cranes are different; different main girder structures have different bearing capacities. If it is often lifted 5 tons, it is appropriate to buy a larger one to avoid a certain overload and unable to complete the operation, which is awkward. With good economic conditions and ample budget, it is wise to

2.choose a larger lifting weight
The problem of the span of the main beam
Depending on the site where the gantry crane is used, it is necessary to consider whether it is convenient to pass the vehicle below, to avoid occupying the place, causing other inconveniences, and also very headache. After installation, it cannot be changed.

3.Whether with a cab
Before installation, the number of driving needs to be considered. If it is used frequently, it is best to have a cab for safety. This way, personnel can stand in the cab to watch the work site below. The wide field of vision increases safety.

4.Do you need to install a frequency conversion structure?
Frequency conversion is more energy-saving, safer operation, and easier to drive, but the cost is higher. If small and medium-sized enterprises, you can ignore it, in order to save costs.

5.The lifting is mainly a trolley and an electric hoist
The lifting structure of each gantry crane is very important. If there is no good lifting or running, it will directly lead to slow operating speed and weak carrying capacity.

6.Consider work levels
For large-tonnage gantry cranes with trolley, try to choose a higher level, such as A6, small cranes, if the carrying capacity is low, try to choose A3 level.

 

Crane Daily Maintenance

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Crane as a large working machinery, safety work is extremely important, not only to master the safety operation rules, ordinary maintenance is particularly important, a small accessories maintenance is also particularly important, so do a good daily inspection is an important guarantee for crane accessories safe operation
1. Check the pulley of crane accessories. The emphasis is on whether the wear amount at the bottom of the groove exceeds the standard and whether the cast iron pulley has cracks. The balance wheel of the lifting mechanism pulley block is easy to be ignored because it does not move in normal circumstances. Therefore, before the installation of crane accessories must check the flexibility of its rotation, otherwise, the length and tension of the cable can not be automatically adjusted by the balance wheel, so as to increase the difficulty of adjusting the rope at high altitude and dangerous degree of operation.
2. Check whether each coupling is loose or even “roll key”. Check whether the elastic rubber ring of the elastic pin coupling has abnormal wear, and pay special attention to the wear condition of the gear ring of the toothed coupling. Due to the poor installation accuracy, under the condition of large offset between the two shafts, the whole gear ring will be bald in a short time. In the hoisting mechanism, if there is such a situation, prone to serious accidents.
3. Check the performance and condition of brake. Brake is an important crane accessories, which directly affects the accuracy and reliability of the movement of each mechanism. Therefore, it is necessary to carefully check the status of the lifting and luffing brakes, and observe the brake brake shoe opening and friction brake skin wear. The belt brake should pay attention to check whether the steel backing lining of the brake belt is cracked, whether the transmission of the brake is flexible, whether the brake frame is intact and whether the elasticity of the main spring and auxiliary spring meets the requirements.
We are in the crane accessories in the daily inspection, from the above aspects can better ensure the performance and quality of crane accessories, so that crane accessories can play out a better use effect. Reasonable daily inspection is very beneficial to the extension of the service life of crane accessories, we must pay attention to it.

 

Matters needing attention for use of metallurgical casting crane

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Metallurgical foundry overhead bridge crane with hook is suitable for metal smelting workshop, mainly used for ladle lifting, moving, pouring and other operations in the steelmaking workshop, relying on the lifting movement of the hook, the longitudinal movement along the direction of the factory track and the transverse movement of the trolley to carry out the work of the machine. Casting crane adopts high temperature steel core steel wire rope, because the safety coefficient of steel wire rope is higher than that of general bridge crane, at the same time, necessary safety protection devices should be adopted to protect the steel wire rope from being damaged at the place of hook group and hoisting beam.
Metallurgical casting overhead bridge crane USES crane with fixed gantry hook to carry heavy pot molten iron, molten steel, liquid slag. Two sets of independent working brakes are set for each driving system of lifting mechanism of crane. Set weight limiter; Double limiter is set at different rising limit positions, and different circuit breakers can be controlled. When the lifting height is higher than 20 meters, the limiter of the falling limit position is set. Overspeed protection device is installed when rated lifting weight is greater than 20t; The door of the driver’s cab and working passage shall be provided with chain protection devices; There is a big car walking mechanism should be set limit and buffer and stop device.
Lifting operation of metallurgical casting overhead bridge crane with hook shall be carried out according to the prescribed route, and sound and light signals shall be issued when the crane starts and moves, and the lifting objects shall not pass over the personnel’s head and over important equipment (operation room, inflammable and explosive gas pipelines and facilities); Crane driver is strictly prohibited to operate large and small cars at the same time, and should sound the horn during the hoisting; Do not use hanging objects to impact other objects or equipment, and there should be no people on the hanging objects.

Grab bridge crane features

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Grab bridge crane is suitable for lifting the ordinary goods in various factories and mines.

Application:
1. Grab bridge crane is suitable for loading, unloading and transportation of bulk materials in power plant, freight yard, workshop and dock.
2. Grab bridge crane cranes are all heavy duty working system.
3. All the mechanisms of grab bridge crane are operated in the driver’s cab, and the directions to enter the platform door of the cab are: end in, side in and top in.
4. The rated lifting weight of grab bridge crane includes the weight of grab.
5. There are two kinds of parallel vertical girder in the opening direction of grab.

Product Main Features:

Grab bridge crane is mainly composed of box frame, grab trolley, truck operation mechanism, driver cab and electrical control system. The pickup device is a grab to grab bulk materials. The grab bridge crane has an open and close mechanism and a lifting mechanism. The open and close mechanism drives the grab to close, grab the material, when the bucket closed, immediately start the lifting mechanism, make the four wire rope average load for lifting work. When discharging, only start the opening and closing mechanism, then the bucket will open and tilt the material. The grab bridge crane is basically the same as the hook bridge crane except that the lifting mechanism is different.

Operation specification:

In order to ensure the safety of crane, all set up handrail, rail height is 1050 mm, 350 mm, set up two level bar, set the height to 70 mm at the bottom of the retaining plate, bridge consists of light, the driver indoor set insulation rubber and the door switch, the transmission parts are set a guard, the railings have set up a security door switch, trip terminals equipped with end, slip line with block hook.

 

Technical Specification and Guidance for Crane Rail Installation

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Many overhead cranes are equipped with corresponding rails, which are generally made of steel. Track is also called the track joint. The length of the track is limited, and it needs to be connected in pairs. Its function is to facilitate the movement of the whole machine or the trolley.

The track joints need to be welded. If the crane rail is installed without welding, it may be dangerous during use. The bolt fastening is also essential.

Generally, in order to allow the crane or the crane trolley to smoothly slip when it encounters resistance through the track, we need to deal with the track joint.

Pay attention to the following aspects during installation:

1. Comply with relevant national standards.

2. Taking into account the influence of the thermal expansion and contraction of the steel rail, there needs to be a gap after welding, and the size should be controlled in the range of 15-18mm.

3. Pay attention to the order of welding. First, the bottom of the rail must be welded, then the rail waist, and finally the rail head.

4. Heat treatment is required after welding. The final step is to polish, to ensure that the track joints are consistent, smooth and tidy with the rail as a whole.

 

What are the Main Parts of Warehouse Crane?

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Warehouse Crane mainly divided into two kinds: warehouse single girder overhead crane and warehouse double girder overhead crane. And warehouse overhead crane is widely used in warehouse for handling materials. However, do you want to know what the main parts of this kind of bridge crane? Today we will mainly talk about it.

The major components of bridge crane composed of  : bridge, electric hoist trolley (with lifting mechanism and operating mechanism), crane operating mechanism and electrical equipment. The hoisting mechanism, hoisting trolley running mechanism and crane running are the three working mechanisms of the warehouse crane. Each mechanism is equipped with a separate electric motor and carries out its own drive.

 

The Purpose and Function of Crane Maintenance

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In the use of cranes, it is inevitable that the moving parts will wear out, the connecting parts will be loose, the oil will decay, or the metal structure will corrode. These problems will cause the crane’s technical function, economic function and safety function to decline. Therefore, in order to prevent and eliminate hidden dangers and ensure that the crane is always in normal operation, the crane should be maintained and maintained before the wear of the crane parts has reached the level that affects the failure of the crane.

Do crane maintenance and repair, can play a role as follows:

1. Ensure that cranes often have outstanding technical functions, make each organization work normally and reliably, and improve its integrity and utilization rate.

2. Ensure that the crane has an outstanding use function, strengthen the maintenance of structural components, and meet the requirements of normal use of the crane.

3. Comply the national environmental protection standards.

4. Reasonably and effectively extend the service life of cranes.