Double Girder Overhead Crane:

• Lifting Capacity: 5t-550t
• Span: 7.5m-31.5m
• Lifting Height: 1m-30m
• Working Class: A5、A6
• Temperature: -25℃～+40℃
• Power Supply: 380V,50HZ, 3-ph

We can also design and manufacture non-standard products according to your needs.

Features of Double Girder Overhead Crane:

• Compact structure, new style, beautiful shape;
• Good technics, long service life;
• Large load capacity, high working duty;
• Stable and flexible operation, safe and reliable;
• Wide application, high performance/price ratio.

Structure and Characteristics of Double Girder Overhead Crane:

Double girder overhead crane mainly consists of bridge, trolley, crane traveling mechanism and electrical system, etc. Double girder overhead crane are three main operating mechanisms: lifting mechanism, trolley traveling mechanism and crane traveling mechanism. And each of them is equipped with separate motors for their own drive.

• Bridge

Consists of main girder, end beam, walkway, railing, overhaul crane cage, cab and its platform, etc.

Main Girder

1. Double main girder, welded box girder and camber meet national standard
2. Steel material is Q235B or Q345B (similar to foreign steel type Fe37 or Fe52).
3. Main weld adopt Lincoln welding and nondestructive test.

End Beam

1. Main end beam is rigid connection. The middle of the two end beam is detachable connected by bolts.
2. The whole bridge is separate into two pieces for transportation and installation.

Others

1. Lay the track on the upper cover plate for trolley traveling.
2. Install the crane traveling mechanism on the side of walkway which connect with main girder.
3. Install the trolley sliding wire on the other side.
4. There is railing on the outboard of walkway in order to ensure the operator safety during maintenance.
5. The cab usually hangs beneath the bridge with electrical control equipment in it and mainly for operator use.

• Trolley

Consists of trolley frame, lifting mechanism and trolley traveling mechanism, etc.

Trolley Frame

1. Welded of steel plate with high intensity and strong rigidity.
2. Equipped with lifting mechanism and trolley traveling mechanism.

Lifting Mechanism

1. One set of independent driving device for single hook and two separate driving device for double hook (main and auxiliary).
2. Lifting mechanism working principle, through high speed rotating of YZR type crane special motor, and gear coupling drive involute gear reducer. Then the low speed shaft of reducer turn the wire rope drum. As long as the control of motors and its positive and negative rotation, can achieve the lifting function of the hook.
3. In order to ensure the security and reliable of lifting mechanism, the brake is installed on the high speed shaft of reducer. And the load limiter is installed on the bearing pedestal which supports the drum to avoid overload.

Trolley Traveling Mechanism

1. Trolley traveling mechanism working principle, the involute vertical gear reducer driven by motor. The low speed shaft of reducer connects to active wheel of trolley frame in the way of centralized driving. The motor adopt double-output gear and there is a brake on one end of it.
2. There are four wheels installed under the trolley. Two of them are active wheels and the others are driven wheels. Driving devices include 1. Motor; 2. Brake; 3. Reducer; 4. Compensating shaft; 5. Coupling; 6. Wheels, etc.

• Crane Traveling Mechanism

1. There are four traveling wheels installed on each side of the two end beams. Two of them are active wheels and the others are driven ones. The driving device of active wheels is installed on the walkway. Here adopt two sets of symmetrical independent driving devices and we call it respectively driven.
2. The reducer adopts circular-arc gear one of which load capacity is higher than involute gear reducer of the same type. All of the mechanisms adopt rolling bearing with A.C. electromagnetic block brake.
3. Driving devices include 1. Reducer; 2. Motor; 3. Brake; 4. Coupling; 5.Coupling; 6. Wheels, etc.
4. The connection of the mechanism parts all adopt gear coupling. In this way, it can work well by gear coupling compensated even there is an error caused in manufacture and installation or deflection between the parts caused by bridge deformation when loading.
5. Active and driven wheel axle support on the angular bearing box for easy assembly and maintenance.

• Electrical System

1. Electric control box layout is reasonable, easy to repair
2. Security trolley line or angle steel trolley line
3. External cable are equipped with mark line number
4. Trolley moving' power is supplied by flat cable
5. The conductor is I steel or C shape sliding line
6. Safety sliding touch line with high conductive rate and low pressure drop; current collector with high speed.
7. Lifting and crane can be independently controlled; also can work separately or together.

Limit and Safety Switch

1. Crane traveling, trolley traveling and lifting mechanism are all equipped with limit switches to limit the travel distance of every mechanism.
2. The circuit will be cut off when the limit switch works, then the mechanism shut down. It will move in the opposite direction when switch on the power again. Thus, ensure the safety.
3. In order to prevent the operators and maintenance staff from the accident, the safety switch is installed on the access door of the walkway which lead the way from cab to bridge, and also on the railing which lead to end beam.

Operation Mode

1. Cab control and ground control
2. Special cabin for bridge crane or capsule driver room, open vision, comfortable operation.
3. The cable have open style, close style, can fixed on left or right
4. The cab hangs under the side walkway of crane bridge close to end beam. Inside of it include control equipment of each mechanism, distribution board, emergency switch and bell push button, etc.
5. Ground control (wire or remote), without professional driver
6. Choose according to customer's different requirements

Overall Drawing of Double Girder Overhead Crane:

Double Girder Overhead Crane Price:

• 5-ton Double Girder Overhead Crane Price Range: $5,800-72,000
• 10-ton Double Girder Overhead Crane Price Range: $6,500-79,000
• 20-ton Double Girder Overhead Crane Price Range: $8,600-95,000
• 50-ton Double Girder Overhead Crane Price Range: $9,800-110,000

Technical Specification of Double Girder Overhead Crane:

Capacity	t	5	10	15	20	30	50	75	100	125	150	200	250	300	350	400	450
Span	S(m)	10.5~31.5	10.5~31.5	10.5~31.5	10.5~31.5	10.5~31.5	10.5~31.5	10.5~31.5	13~31	13~31	13~31	13~31	13~31	13~31	13~31	13~31	13~31
Lifting height	m	6~16	6~16	6~16	6~16	6~18	6~16	6~20	6~20	6~20	6~22	6~20	6~20	6~24	6~24	6~24	6~24
Lifting speed	m/min	11.5	8.5	7.9	7.2	6	6	3.9	3.1	3.9	3.5	2.6	2.2	2.4	2.2	2.6	2.1
Trolley speed	m/min	37.2	37.4	40.1	40	37	31.3	31.3	33.6	33	40	32	32	28	28	31	27
Crane speed	m/min	70.6	70.6	74.3	75.1	64.9	58.5	61	61.8	62.3	68	48	50	42	42	45	42
Work duty		A3~A7	A3~A7	A3~A7	A3~A7	A3~A7	A3~A7	A3~A7	A3~A7	A3~A7	A3~A7	A3~A7	A3~A7	A3~A7	A3~A7	A3~A7	A3~A7

Cautions of Safe Operation of Double Girder Overhead Crane:

1. Must not lift weights exceed the rated lifting capacity of double girder overhead crane.
2. Strictly prohibit goods lifting overhead the human beings.
3. When lifting overhead, the hook position must not less than one person's height.
4. Strictly prohibit obliquely hanging and lift the objects buried in the ground.
5. Must not brake through motor's sudden reversal. Only permit when accident happens.
6. Must send warning signal before each operation of double girder overhead crane.
7. Should consider the brake ability before lifting the weights close to the rated load in order to ensure safety.
8. Before driver leave the cab, the double girder overhead crane must be placed to the fixed park position, with nothing on the hook, every control handle at zero position and cut off the main switch.

Application of Double Girder Overhead Crane: 

1. Heavy industrial production: In the steel, metallurgy and machinery manufacturing industries, double girder overhead cranes are used for lifting heavy equipment, raw materials and finished products, such as steel ingots and large machinery components. 
2. Warehousing & Logistics: In large warehouses or logistics centers, double girder overhead travelling crane is used for loading and unloading, stacking and transferring of goods.
3. Energy and power industry: In the energy and power sector, double girder overhead travelling crane is used for lifting and installing large equipment, such as generator sets, transformers and so on. 
4. Shipbuilding and offshore engineering: In shipyards and offshore engineering, double girder overhead travelling cranes are used for lifting and assembling hull components, large modules and heavy equipment.
5. Construction projects: In large-scale construction projects, double girder overhead travelling crane is used to lift building materials, prefabricated components and heavy equipment.
6. Automobile manufacturing: In the automobile manufacturing industry, double girder overhead travelling crane is used for handling and assembling large body parts, molds and equipment.
7. Specialized environmental applications: Double girder overhead travelling crane can be customized according to special environmental requirements, such as explosion-proof, high-temperature resistant and corrosion resistant. For example, in high-risk environments such as chemical, petroleum, and nuclear power plants, the specially designed cranes are able to safely and efficiently complete lifting tasks.
8. Automation and Intelligent: Double girder overhead cranes are gradually automated and intelligentized. By integrating sensors, control systems and IoT technologies, cranes can realize remote monitoring, automatic operation and fault diagnosis, further improving productivity and safety.