7 ton overhead crane for sale good price. Affordable 7 ton overhead crane, with high safety to improves your material handling efficiency. Overhead crane with various designs at your selection, one year grantee is available. Custom 7 ton overhead crane is for you. Check Dongqi 7 ton overhead crane projects now.
7 ton overhead crane has many advantages as compact structure and strong rigidity. It is a kind of light and small cranelifting equipment that can be matched with CD1、 MD1 electric hoist and used together.
Main parameters of 7 ton overhead crane
- Lifting Capacity: 7t
- Span Length: 10.5-31.5m
- Lifting Height: 6-18m
- Working Class: A5, A6
- Ambient Temperature: -20-40℃
Various types of 7 ton overhead crane
As for special using purpose, it includes explosion proof bridge crane for coal mine, warehouse grab overhead crane, warehouse electric single girder overhead crane, workshop single girder overhead crane, workshop grab overhead crane, customized single girder low headroom overhead crane, grab bridge crane.
Single girder overhead cranes of Dongqi Hoist and Crane
FEM underslung single girder overhead crane for sale
Explosion proof single girder overhead crane for sale
Electric hoist single girder overhead crane for sale
Low Headroom single girder overhead crane for sale
Single girder overhead crane European style for sale
Suspension single girderoverhead crane for sale
Double girder overhead crane offering of Dongqi Hoist and Crane
Features of overhead cranes
- 1. Various types, customized service
- 2. Durable material, reliable quality
- 3. Tiny size, portable weight
- 4. Simple system, easy maintenance
- 5. Fast speed, flexible move
7 ton overhead crane application
In various industries and places, the 7 ton overhead crane is widely used in workshop, factory, warehouse, stock yard and other different places to lift material. However, the light overhead crane is banned to use in the flammable, explosive, corrosive work condition.
Main components of overhead crane
The light overhead crane system is mainly composed of four parts: main girder, electric hoist, travelling mechanism and electric control devices.
Operations of 7 ton overhead cranes
It has two types of operation, ground control and cabin control. And the crane cabin has two types, open type and close type and can be installed on the right or left according to practical need. And the direction of entering the gate has two forms, sideway and ends in order to satisfy the users’ choice under different conditions.
Electric safety devices on 7 ton overhead crane
- Lighting switch box is installed on the 7 ton overhead crane to ensure the power supply of working lighting and ringing.
- Travelling limit switch on the 7 ton overhead crane to make the machine driven by motor work in certain area, and avoid accident.
- Emergency switch is installed at the side of cabin of the 7 ton overhead crane. Under emergent condition, the driver can easy and fast to cut off the power of controlling circuit.
- Door safety switch installed on the door and hatch of the 7 ton overhead crane. When someone goes up or down the crane or walks on the crane, this switch can avoid accident caused by the driver.
7 ton overhead crane for sale good price. Affordable 7 ton overhead crane, with high safety to improves your material handling efficiency. Overhead crane with various designs at your selection, one year grantee is available. Contact us to custom 7 ton overhead crane is for you.
7 ton overhead crane cases of Dongqi Hoist and Crane
Lifting capacity offering of Dongqi Hoist and Crane
More information on overhead crane, gantry crane, jib crane, electric hoist is our Dongqi Hoist and Crane Product Center.
Overhead Crane FAQ: What are general overhead crane problems and how to solve them?
- Question 1: Why does Dongqi Crane use PLC on overhead crane?
- Answer: PLC is the abbreviation of programmable logic controller. Its basic structure are composed of power, CPU, memory, input/output interface circuit, function module and communication module. PLC can change the form of relay-contacts control, and can make it adjustable for electric motors' speed of every file, acceleration time and braking time according to practical conditions. PLC functions include calculating, controlling, programming, communicating, diagnosing, processing. Because PLC has various advantages and can make heavy duty overhead cranes more safety and convenient, Dongqi Enterprise apply PLC in overhead crane system. Its advantages are following. 1. Convenient use, simple program 2. Strong function, highly cost-effective 3. Complete hardware, convenient use for customers, strong adaptability 4. High reliability, strong anti-interference capability 5. Little work for system's design, installation and test 6. Little work for maintenance and convenient maintenance.
- Question 2: What's the system of hoist overhead crane?
- Answer: Electric hoist overhead crane mainly includes lifting mechanism, travelling mechanism (trolley travelling mechanism and overhead crane travelling mechanism) and rotating mechanism. First is lifting mechanism, it refers to electric hoist. It is composed of driving device (electric motor), braking device (brake), transmission device (reducer) and fetching rotating device (hook, grab, magnetic disc, and wire rope, chain, trolley, drum, sprocket and rope-guiding device). Second is horizontal travelling mechanism, it is trolley travelling mechanism. Travelling trolley is composed of electric motor, braking device (brake), transmission device (reducer) and trolley wheel device. Third is vertical travelling mechanism, it is overhead crane travelling mechanism. This mechanism includes driving mechanism (electric motor), braking device (brake), and transmission device (reducer) and overhead crane wheel device. The advantage of electric hoist overhead crane is that it adopts three-in-one driving device. It combines driving device (electric motor), braking device (brake) and transmission device (reducer) together. It is a compact and light driving device without shaft.
- Question 3 : How do bridge overhead cranes supply power ?
- Answer: First is through flexible cable. The power of the lifting overhead crane is supplied by AC power system. Because the work of the overhead cranes is movable, the overhead crane and the power can't be connected in fixed way. In general, the flexible cable is used to supply the power. When the overhead crane system and the trolley move on the tack, flexible cable can stretch and roll along the track. Second is through slide wire and electric brush. Three phase AC power is transported into cabin's protection box through three main slide wires and electric brush, then transported to overhead crane system's motor, electromagnet and AC control station through wire way. Third is through auxiliary slide wire and electric brush. This refers to the power supply of magnetic brake, trolley's hoisting mechanism and trolley's motor.
- Question 4 : What to do when the overhead crane trolley line is out of power ?
- Answer: The reason is that electric brush climbs in the conductor, the brush wears seriously, conductor joint is not smooth, single connector is used, rail joint becomes loose. The correct way is to check whether the brush wears seriously, change electric brush, adjust the connecting joint, and adopt double-brush connector.
- Question 5: What to do when the guiding rail is deformation, the collector doesn't work?
- Answer: The main reason is the temperature is too high, the distance between lifting racks is too long or loose. It is useful to adopt anti-heat plate partially, add sun shield outdoors, increase the number of trolley line lifting racks, correct the conductor and screw down the screws.
- Question6 : What to do when the overhead crane trolley line shakes seriously?
- Answer: The reason is that fork can't absorb the transmission error, guiding-rail has poor straightness, and lifting rack is loose. The right way is to modify tractor, adjust the straightness of guiding-rail, and tighten the screw mounts.
- Question7: What are the factors which influences overhead crane working speed?
- Answer: Overhead crane working speed includes lifting speed, trolley travelling speed, overhead crane travelling speed. Working speed is influenced by many factors.
- First, it is related to the weight. The overhead crane with small and medium lifting can adopt high speed to improve efficiency, the overhead crane with heavy lifting is suitable to choose low speed to reduce driving-power and improve travelling stability and safety.
- Working speed is also related to working class and working requirement. The overhead crane with high class, frequent use and high efficiency can adopt fast speed, working mechanism with low class and adjusting purpose can adopt low speed. The overhead crane only used for equipment installation and maintenance can choose low speed.
- According to practical needs, it can also adopt double speed (high and low speed), dead speed or adjustable speed. What's more, working speed is also related to working room. The overhead crane with long travelling distance, high lifting height is suitable for high speed. The overhead crane with short travelling distance is not suitable for high speed. With development of industry, the overhead crane with much transporting work mostly adopts high speed.
- The overhead crane used for installation and maintenance adopts adjustable speed. For some overhead cranes with special functions, such as the overhead crane for quench, should has fast-down device, for overhead crane with high lifting height, it should improve lifting speed, adopt low speed for heavy material, high speed for no-load, or high down-speed to increase efficiency.
- Question8: What to do when the brake can't stop the braking-wheel?
- Answer: The reasons are as following: the leverage hinge is stuck, braking-wheel and friction plate have oil pollution, electromagnetic core doesn't have enough travelling distance, braking-wheel and friction wheel are wearied seriously, main spring is loose and damaged, locking-nut and tie rod are loose. Make lubrication and exclude stuck fault, clean the oil pollution, adjust the brake, change the friction plate, change the main spring and locking-nut, tight the locking-nut, check the impeller driving mechanism.
- Question9: What to do when the brake is too hot, the friction plate wears fast.
- Answer: The braking-shoe is loose, it doesn't break off the braking-wheel totally, and causes friction. The gap between two braking-shoe and braking-wheel is not even, or the gap is too narrow. The assistant-spring of short distance brake damages or bends, the braking-wheel surface is very tough. What to do is to adjust the gap, change or maintain the assistant-spring, processes the braking-wheel surface. The reducer has uneven tapping and the machine cover vibrates when the reducer and gears mesh. Just change the gears.
- Question10: Why overhead crane system need buffers?
- Answer: Three kinds of buffers are used widely, spring buffer, rubber buffer and hydraulic buffer. Spring buffer is reliable and convenient to maintain. Rubber buffer has simple structure. Hydraulic buffer can absorb large hitting energy and has no rebound effect. When limiting stopper of travelling extreme position or brake is in trouble, due to the inertia, the overhead crane system moving in the end or the trolley on the main girder, will hit against the stopper set in the position. But overhead crane buffer can absorb the travelling energy of overhead crane system or trolley and reduce impulsion. Buffers should be set between the bridge overhead cranestravelling on the same track, or between the double trolleys on the same girder.
- Question11: What is the anti-collision device on overhead cranes?
- Answer: It mainly includes laser type, ultrasonic type, infrared type, electromagnetic type, all use the principle that light or radio wave travels, reflects and the distance can be measured. When two overhead cranes travels to pointed position, the overhead crane mechanism rings alarm bell and gives the stop command at the same time.
- Question12: How does anti-deflection device protect overhead cranes?
- It includes wire-rope type, cam type, chain wheel type and skew indicator and other automatic adjustable devices. When the bridge frame deflects to some degree, it can give signal to the operator and adjust itself automatically. When the overhead crane frame deflects seriously, it can cut the power automatically, stop the travelling mechanism and protect the safety.
- Question13: What is the function of safety hook of overhead crane?
- Answer: Safe hook is an important part of bridge overhead crane. What are functions and types of safe hook?
- Safety hook is mainly used for single girder overhead crane. Lifting material at one side of main girder, the material has a tilting torque against trolley, anti-tilting torque from vertical gauge wheel or horizontal gauge wheel can keep the trolley balance. But this kind of way can't ensure the safety under the condition of cyclone, outside impact, wheel broken, maintenance and repair. Thus this overhead crane should be installed with safe hook. According to trolley and wheel, safe hook has different structures.
- Question14: How to inspect the safe hook of overhead crane?
- Answer: The inspection of the overhead crane safe hook is necessary. When the trolley travels along the main girder, there is no stuck between safe hook and rail or main girder web. Web has no weariness. The gap between safe hook and rail should meet the design requirement. Bolt is tight and on the right location, weld is seal, safe hook has no damage, such as abnormal deformed. Function check is the basic method, just through visual inspection and test operation.
- Question15: how to lubricate the large and heavy overhead crane?
- Answer: Lubrication is necessary for large overhead crane. Reasons to lubricate your overhead crane It can control friction, reduce weariness, down overhead crane temperature, avoid rust and form seal. These functions rely on each other and influence each other. If the friction can't be controlled, the weariness can/t be reduced, this will lead much friction heat and items high temperature, thus to damage the friction surface lubrication and lubricating material. How to lubricate your overhead crane?
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- ome parts should be lubricated regularly, such as shafts, holes and friction surface with relative move. Due to different working condition, the lubricating points are different. For various kinds of overhead cranes and different lubricating parts, every lubrication should meet the standards and requirement of instructions. It is good for overhead crane to make regular lubrication and check. Lubricating with qualified oil can ensure the overhead crane work normally and avoid early weariness. Bad oil can lead mechanical accident, even damages equipment, influences safe producing. Lubrication plays an important role in overhead crane's maintenance. The lubricating oil can influence the effect directly.
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Single Girder Overhead Crane with FEM crane standard
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