/kloc-in the 0/4th century, a jib crane driven by human and animal power appeared in western Europe. /kloc-in the early 20th century, bridge cranes appeared; The important wearing parts of cranes, such as shafts, gears and slings, began to be made of metal materials and started to be driven by water.
/kloc-In the late 20th century, steam-driven cranes gradually replaced hydraulic cranes. Since the 1920s, due to the rapid development of electrical industry and internal combustion engine industry, various cranes powered by electric motors or internal combustion engines have basically taken shape.
Crane mainly includes hoisting mechanism, running mechanism, luffing mechanism, slewing mechanism and metal structure. Lifting mechanism is the basic working mechanism of crane, which is mostly composed of suspension system and winch, and some lift heavy objects through hydraulic system.
Running mechanism is used to move heavy objects vertically and horizontally or adjust the working position of crane, and generally consists of motor, reducer, brake and wheel. The luffing mechanism is only equipped on the jib crane, and the amplitude decreases when the jib rises and increases when it falls, which can be divided into two types: balanced luffing and unbalanced luffing.
The slewing mechanism is used for slewing the boom and consists of a driving device and a slewing support device. Metal structure is the skeleton of crane, and the main load-bearing components such as bridge, boom and gantry can be box structure or truss structure, or web structure, and some can use section steel as supporting beam.
How is the invention of cranes described in history? It is speculated that the specific time of the invention of the crane is about BC 10.
At that time, in an architectural manual, a Roman architect named Vit Rubis described the crane. This machine is equipped with a mast with a pulley at the top. The position of the mast is fixed by pulling the rope, and the rope passing through the pulley is pulled by the winch to lift the object.
Some cranes can use two masts to form a herringbone and move the lifted heavy objects laterally, but there is not much movement range, so it is very difficult to operate. In medieval Europe, people revered God, and tall churches were everywhere.
If you want to get building materials to the roof, you can't do without a crane. As for the towering spires, although the single stone used is very small, the height to be raised is not comparable to that of previous buildings.
This may be due to the invention of the pole crane. The so-called pole cranes all have a long arm extending horizontally, which was called Hawke in the architectural history of medieval England.
Since 1078, this long-arm crane has also been used in the construction of the Tower of London. It is worth mentioning that after the building is completed, people are not in a hurry to move the crane because they think it may be used for maintenance.
It is said that there is a16th century crane next to the Cologne church, which has stayed for 300 years and has not been taken away. After entering the14th century, the jib crane appeared in Italy.
It has an inclined cantilever with a pulley at the top, which can be lifted and rotated. It is very flexible and efficient to use, and soon appears on the docks of European countries.
Since19th century, people have made great improvements on cranes. 1805, British engineer Lenny built a batch of steam cranes for them at the request of London Wharf.
1846, the hydraulic crane came out, and its invention should be attributed to Amstrom. Since the beginning of the 20th century, tower cranes have been used in Europe.
In 1930s, the movable boom appeared on the crane. With all kinds of cranes, it is possible to build modern buildings and engage in large-scale cargo handling.
Wylie company in the history of cranes mentioned above is a mechanical system manufacturing company, which has been famous for manufacturing fixed and mobile cranes for decades. Of course, we will also introduce other manufacturers in the order of appearance. During the period from 1940 to 1949, the market gradually recovered confidence. When the world returns to peace, people no longer use cranes to hang destructive bombs on the battlefield, but use them to rebuild the devastated country. In the first volume of the 500-year earthmoving series, the author Heinz-Herbert Cohrs raised a question about this period: "Who else is not making construction machinery?" Now, we can also ask the same question with a crane. Obviously, the engine is stronger now, and the crane control system (electric, hydraulic and pneumatic) is more sensitive and widely used. Some very advanced tower rotary cranes have appeared in the market, and many new uses of cranes have been developed all over the world. Take a mobile crane as an example. By the end of1940s, it had become an indispensable auxiliary machinery, paving the way for the advent of larger machinery!
Fig. 204: This pneumatic human rail crane is driven by a truck engine, with a lifting weight of 7 tons and a lifting radius of 7 meters.
Figure 205: This Wylie DL rope tensiometer was introduced in 1948 to help monitor the load torque. It is a pioneer of complex electronic systems.
Where is the history of cranes detailed? Please make it clear that in the first few years after the war, the world-wide industry was born and the crane industry almost stopped.
But by the end of this decade, the construction of cranes has become diversified and spread all over the world, and its unprecedented vigorous development seems to have injected new energy into the whole industry. Light cranes are put into the work site and prepared as the main machinery, because people realize the advantages of not having to disassemble them in the workshop.
These new designs no longer require the assistance of other lifting equipment-compared with the complicated design before installation. However, before all this, there was a terrible World War II.
By 1940, Europe was completely at war. In the decades after the war, great political, economic and social changes have taken place in Europe and other parts of the world, which will affect the whole social structure, including construction and crane industry.
In the United States, steam engines have begun to be changed to diesel engines-by 1953, more than 50% of locomotives will use diesel engines. During the war, the mass production of excavators, scrapers and cranes continued.
For example, in 1940, we see that Thew has launched a new series "Lorain Motocrane". This includes three kinds of cranes, which is the first crane with its own chassis installed in history.
The lifting capacity of the smallest MC-2 is 7.6 tons, that of MC-2 is 9.9 tons, and that of MC-3 is 13.5 tons. Many of these cranes are used in the army, and some are also installed in ports as port cranes (MC-4 type).
Of course, this war has weakened the number of strong men who can engage in the crane industry, and there is a serious shortage of excellent crane drivers. At work, A C Burch, an experienced mechanic, and Professor L K Jenkins, who graduated from the United States Naval Academy, took a two-day crane business course.
These two gentlemen are like the founders of operator training as we know it today. They have actually designed power cranes, have a deep understanding of cranes, and are happy to teach them.
Who can tell me everything about tower crane, especially its development history, origin and background knowledge? Tower crane originated in western Europe, and the first patent for tower crane for construction was issued in 1900. 1905 saw the crane with fixed tower and boom, 1923 made the prototype of modern tower crane, and the first relatively complete modern tower crane appeared in the same year. 1930, Germany has started mass production of tower cranes and used them in buildings. 194 1 year, the German industrial standard DIN8770 on tower cranes was published. According to the standard, the product (tm) of lifting weight (T) and amplitude (M) is used to express the lifting capacity of high-torque tower crane.
From the technical development of tower crane, although new products emerge one after another, and new products have improved in production efficiency, simple operation, convenient maintenance and reliable operation, the technology of tower crane has not changed fundamentally. The research of tower crane is developing in the direction of combination. The so-called combination means that the tower is divided into several parts according to the structural and functional characteristics, and each part is divided into several modules according to the requirements of serialization and generalization and the principle of modular system. According to the parameter requirements, select appropriate modules to form tower cranes with different technical performance characteristics to meet the specific needs of construction. The implementation of combined tower crane is helpful to speed up the development progress of tower crane products, save product development costs and better serve customers.
Tower cranes are divided into two categories: upper rotary tower cranes and lower rotary tower cranes. Among them, the former has higher bearing capacity than the latter. In many construction sites, what we see are tower cranes with top-to-top lifting and joint connection. According to whether it can move, it can be divided into walking type and fixed type. The tower body of the fixed tower crane cannot rotate, and it is installed on the whole concrete foundation or X-shaped concrete foundation in a strip shape. In housing construction, it is generally fixed.
Tower cranes are divided into QTZ 125 (torque 1250), OTZ80 (torque 800), QTZ63 (torque 630), QTZ50 (torque 500), QTZ40 (torque 400) and QTZ3/kloc-0.
Who can briefly describe the development history and present situation of tower cranes in the world and in China? You can check the international literature and history, because it is more authoritative.
Development history and present situation of domestic tower crane: According to research, tower crane was invented in Europe in the early 20th century. 1900 won the first patent for tower crane, and 1905 saw the boom crane with fixed tower body. After World War I and World War II, tower cranes have developed rapidly, and in recent years, there are various types and strong demand.
China tower crane started in 1950s. Throughout the development history of 50 years, China's tower crane industry has gradually formed a relatively complete system and series spectrum from scratch, and tower crane has become the key equipment in construction, and tower crane industry has also become one of the fastest-growing construction machinery industries in China.
It only took us 50 years to complete the development of tower cranes in developed countries for hundreds of years. Now China tower cranes have entered the international market in batches. At present, China has become a big producer of tower cranes in the world, and it is also one of the main demand markets of tower cranes in the world.
→ Click on the right to see more.
The development history and origin of automated warehouse The emergence and development of automated warehouse is the result of the development of production and technology after the Second World War. In the early 1950 s, the overhead warehouse of bridge stacking crane appeared in the United States; At the end of 1950s and the beginning of 1960s, the overhead warehouse of roadway stacker operated by drivers appeared. 1963, the United States took the lead in adopting computer control technology in the overhead warehouse and established the first computer-controlled overhead warehouse. Since then, automated elevated warehouses have developed rapidly in the United States and Europe, and formed a special discipline. In the mid-1960s, Japan began to build overhead warehouses, which developed faster and faster, becoming one of the countries with the largest number of automated overhead warehouses in the world.
It is not too late for China to develop the elevated warehouse and its material handling equipment. 1963 developed the first bridge stacker (Beijing Institute of Lifting and Transportation Machinery, Ministry of Machinery), 1973 developed the first computer-controlled automatic overhead warehouse in China (15m high, Beijing Institute of Lifting and Transportation Machinery, Ministry of Machinery). The warehouse is 1980. Up to now, according to incomplete statistics, the number of overhead warehouses in China has exceeded 500. Elevated warehouse has become an indispensable technology for enterprise logistics and production management because of its high space utilization rate, strong ability to enter and exit the warehouse, and computer control and management, which is conducive to the implementation of modern management in enterprises.
Automated overhead warehouses are widely used in almost all industries. In China, the application industries of automated elevated warehouse mainly include machinery, pharmacy, IT, metallurgy, chemical industry, aerospace, electronics, food processing, tobacco, household appliances, printing, distribution centers, airports and ports.