1、Characteristics and Developmental Tendency of Modern Cranes With rapid development of modern science and technology, magnification of industrial production scale and improvement of automation level, application of cranes is becoming widespread and its function is obvious. Meanwhile, requirements for
2、 cranes are more and more strict. Especially, the widespread use of electronic computer technology spurs lots of subject-crossing advanced design approaches and accelerates the improvement of modern manufacturing and detecting technology. Fierce competition in international market becomes more depen
3、dent on the competition of technology. All of these impel technological functions of cranes into a brand-new developmental stage. Cranes are facing a tremendous transformation. Our country is entering global international competitive market at an unprecedented rate and crane manufacture is confronte
4、d with a new situation where opportunities and challenges coexist. Thus, it is crucial for cranes to develop and innovate constantly. I want to make a brief explanation about characteristics and developmental tendency of modern cranes with examples, based on new theories, technology and trend of cra
5、nes at home and overseas. 1. Make the key products large, high speed, endured and specialized Because of continuous expansion of industrial production scale, increasingly improvement of production efficiency and rising proportion of money spending on loading and unloading and transporting materials
6、in the process of production, required amount of large or high-speed cranes is increasing. Lifting quantities become larger, working speed becomes higher and requirements of energy-consuming and reliability become stricter. Cranes have already become a critical link in the process of automation prod
7、uction. Cranes should be easy to use, maintain and operate and have high security, less troubles and long average time between failures. The central issue in international market production competition is reliability, and many companies abroad have drawn up inter-controlled standard of reliability.
8、The most important for us to catch up with and surpass world advanced level of cranes function is to improve reliability, to make cranes durable, less troubles, maintainable and economic to be used. At the moment, the biggest floating crane in the world weighs 6500t, chain crane 3000t and bridge cra
9、ne 1200t. Diversity of industrial mode of production and customers need makes crane market expanding and products renewing constantly to satisfy special needs with specific functions and bring its best usefulness into play. Functions of various kinds of cranes are improving. DEMAG ERGOTECH has devel
10、oped a crane special for aircraft maintenance, which has made its own way into international market. This crane is great in length and lifting height and has accurate halt. When a flexible maintenance platform fixed under lifting cart, it can reach every part of the aircraft. With the fast developme
11、nt of nuclear power stations in the world, cranes which are special for them achieve corresponding development. For example, annular bridge crane in reactors space, working under radiative circumstances, is used to lift dangerous load such as top cover of pressure container and components in reactor
12、s. It requires high reliability, high security, the ability to determine location accurately and automatically and transfer goods to a lower level, as well as various kinds of protection and particular security devices. 2. Make series of production modularized, combined, standardized and practical M
13、ost cranes are produced by series and batch, thus use of systematic multi-objections entire optimization to design series of cranes has already become the key point in development. Through rational matching of series main parameter, its functions can be improved, manufacturing cost can be reduced, a
14、nd degree of general purpose can be raised. Use less specification spare parts to compose series production with multi-species and multi-specifications. And thus, the requirements of customers can be fully satisfied. By using modularized design instead of conservative entire design, we can make comp
15、onents with similar functions into standard modules which have various uses, similar connective key factors and are interchangeable. Through combination of different modules, we can make different kinds and specifications of cranes. There are only several modules involved when it comes to crane impr
16、ovement. To design a new style of crane, all that you do is to choose different modules to recompose. Because of improvement in degree of general purpose, single products with small serial production can transform into module production of pretty great batches. As a result, we can achieve specializa
17、tion production with high efficiency and cut manufacturing cost. It can satisfy marketing demands and increase competitive capacity by composing cranes of various series and specifications using less modularized forms. Bridge crane produced by DEMAG ERGOTECH considered carefully modularization and c
18、ombination. It makes inter-parameter of series, entirety, mechanism and components matched with each other. The distribution of capacity obtains most economic and suitable effects. To make the main components of lifting mechanism reaches its largest general purpose, the method that the result of lif
19、ting weights multiplying lifting speed is a constant has been used. There are more specifications derived through changes of pulley multiplying power. Series of 5-125t bridge cranes only need four basic lifting carts even with various working ranks. Module series of standard wheel cases, which are p
20、roduced by the company, have various groups of linking holes which can choose different drive unit to form platform carts. They can also combine with metal construction components to be used as running machine of various kinds of cranes； its wheels have several forms of surfaces to be chosen. Becaus
21、e of no basic distance limit and flexible combination, they are widely used. The companys series of end bridge standard modules have commercialized. It resorts to frictional cycle and high intensity bolt link which improves interchange and accuracy of sizes and reduces machining of connecting covers
22、. It can connect to each main beam quickly and effectively. There are two kinds of end beam modules； one is suitable for single beam and the other is for double beams. According to length and weights, end beam style can be decided. 3. Make productions for general purposes small, light, simple and di
23、versified There are quite a number of cranes used in general workshop and storehouse, and thus they have light work and the requirement is not very strict. How to improve application of these cranes and to cut manufacturing cost is critical to win in the marketing competition. Considering comprehens
24、ive benefit, the need to decrease the height of cranes as low as possible, to simplify the constructions and to reduce weights and wheel pressure can also decrease structures height, lighten structure composition and reduce cost of producing and maintenance. So there will be fast development of elec
25、tric calabash bridge and light beam cranes, and bridge cranes for general purposes will be replaced by them. The needs of customers advance diversity of cranes. Series parameter scale of cranes expanding and functions enlarging, product of one machine for several uses will obtain further development
26、 to increase capacity of dealing with emergencies. The proportion of using wireless remote control under normal conditions will increase. DEMAG ERGOTECH has formed standard crane series of light combinations after long period explosion and innovation. The whole series compose of various productions
27、such as combination “工 ” style single beam, hanging case single beam, horn cart case single beam and case double beams. There are altogether fifteen forms of connection between main beam and end beam. This is suitable for needs of different structure and lifting goods. Each specification of crane ha
28、s three single speeds and three double speeds to be chosen. There are seven operating ways. In addition, different electric conduction pattern and different electric control pattern can match hundreds and thousands of cranes through different combinations to fully satisfy different needs of customer
29、s. Another advantage of the crane is that they are light. Compared to productions at home, its lifting weight is 32t and length 25.5m compared to 46.4t-weight of double beams cranes in our country, 28.3t- electric calabash bridge cranes. Weight of DEMAG electric calabash bridge crane is only 18.5, which is lighter than domestic productions by 60 percent and 35percent respectively.
