Повышение износостойкости роликов натяжки поручня эскалатора метрополитена Реферат

An escalator is a conveyor transport device to transport people, consisting of a staircase whose steps move up or down on tracks, which keep the surfaces of the individual, steps horizontal. Most escalators also have moving handrails, which approximately keep pace with the movement of the steps. The direction of movement can be permanently the same, be controlled by personnel according to the time of day, or automatically be controlled by whomever arrives first, someone at the bottom or at the top. In the last two cases there has to be an alternative nearby.

Escalators are effective when used as a means of guidance and circulation. In a complex transport situation, such as a city’s subway hub, people need to be kept on the go, particularly at busy times, to reduce congestion and avoid excess waiting. When used as part of a museum or similar building, an escalator is able to direct visitors to exhibitions or exits simply by its appearance and the direction in which it’s traveling.

The purpose of an escalator is to transport people. It performs this task efficiently, allowing individuals to move between potentially many floors of a building in a relatively short amount of time, when compared to a staircase, for instance. 

The purpose of the work is to describe the improvement of wear resistance of the handrail of the escalator.

The tasks are:

1) to analyze the importance of escalators;

2) to show the changes of escalators during the years;

3) to observe the improvement of escalators.

Escalators can save energy during quiet periods, since they can be turned off, essentially becoming a staircase.

Visit any large department store, shopping mall, metro station, airport or stadium anywhere in the world and you are sure to find escalators carrying people quickly and safely to their destination. The escalator has become an integral part of the urban landscape. While passenger elevators were in common use since the 1870s, it was not until 1899 that the Otis Elevator Company introduced the world’s first commercially successful moving stairs.

In addition to lifts, escalators have become the main method of transport for people inside buildings, commercial facilities or even outdoor areas. In fact, there were more than 500 thousand escalators and moving walks around the world at the end of 2008. Their market can be divided in: transit escalators (45%), commercial escalators (40%) and moving walks (15%). The structure of the industry is characterized by the dominance of four big companies whose joint share was 70% during 2006. The annual energy consumed by escalators is 904 GWh and the potential energy savings are around 30%.

In order to achieve the above mentioned savings, it is necessary to use high efficiency motors, drives, transmissions, bearing, etc. Maintenance and lubrication must also be taken into account to keep the efficiency at its maximum level. Apart from design aspects, the control strategies of the electric motor being used as the prime mover have a significant impact on the energy consumption. Usually, the energy wasted when the escalator is unloaded can be partially avoided by stopping the escalator (zero speed standby mode) or by using a reduced speed (low speed standby mode). In any case, the running speed variations of escalators must be carefully designed and maintained in order to reduce potentially hazardous situations. For the sake of passenger safety, low speed standby mode is commonly preferred instead of zero speed standby mode.

The evaluation of energy savings in a particular installation should be based on the characterization of the actual energy consumption of the escalator, which strongly depends on the traffic pattern. For example, in escalators with steady or heavy traffic there is little room for energy savings by adjusting the running speed. 

The basic design of escalators has been in use for more than a century without any significant changes. The first patent was taken out in 1859 by Nathan Ames for a revolving stairway in the form of an equilateral triangle. This design was the first idea for such a lifting mechanism.

The modern escalator comes from inventions which are more than one hundred years old, and its basic design has not changed. Up to now, the mechanical design has been carried out in an experimental form; therefore, testing any changes is costly both in terms of time and money.

The way to reduce the experimental cost and time consists in simulating the kinematic and dynamic behavior using multibody dynamic software. The use of these kinds of tools will allow time to be saved because the escalator does not need to be built. In addition, the model can be sensorized and tested in an easy way. This time-saving is very important in their search and design concerning a mechanism that is becoming a commodity product. There are some models which have been successfully developed by simulation software.

Otis, in its tradition of innovation, has continued to refine the escalator since it pioneered its introduction. 

Early escalators had solid rubber handrails driven by metal chains. The chains traveled in a lubricated steel channel. The result was that passengers often wound up with oil-stained hands or gloves. 

Otis replaced this design with a tension-driven rubber and canvas handrail that was guided in a simple unlubricated channel. Later, Otis refined this design by introducing pinch-resistant handrails to prevent the possibility of passengers’ fingers from being caught. 

Another Otis innovation was to extend the handrails 40 cm (16 in) beyond the point where the steps disappear at the landings. This simple design improvement dramatically increased escalator safety. 

An escalator is a conveyor type transport device that moves people. It is a moving staircase with steps that move up or down using a conveyor belt and tracks keeping each step horizontal for the passenger. However, the escalator began as an amusement and not as a practical transport.

• Escalators are required to provide continuous mass transport of people.

• Escalators in department stores rise at an angle of between (30°-35°). The 35° escalator is more economical, as it takes up less surface area.

• In accordance with a worldwide standard, the width of the step to be used is 60 cm (for one person width)80 cm (for one- to two people width) and 100 cm (for two people width).

• According to current assessment, or average one escalator is installed for every 1500m² of sales area.

Otis wrote history with the introduction of the escalator in 1899. Today, it continues to improve the product through ongoing innovation.

Newer truss designs take up less space than previous systems. Increased standard rises of up to 10 meters (33 ft), versus an industry convention of 6 meters (20 ft), allow for multiple applications with the same look, without the need for costly custom design.

A modular approach allows each installation to be tailored to meet specific architectural requirements. Balustrades and exterior cladding, ranging from conventionally painted metal to stainless steel and glass, can be fully customized to complement the design of any building. Lighting options provide a further means of expression to enhance the installation’s overall look. The result is a streamlined appearance that can be incorporated more easily into a building’s design scheme.

Designing a safe transition point - where passengers step on and off the escalator - was one of the major problems in creating a successful moving stairway. A number of methods had been attempted before Otis solved the problem.

Early escalators had solid rubber handrails driven by metal chains. The chains traveled in a lubricated steel channel. The result was that passengers often wound up with oil-stained hands or gloves. 

The extended handrail permitted passengers to grasp the rail and steady themselves before stepping onto the moving stairs. It also aided them when stepping off. The extended design improved safety by making it difficult for hands to be caught at the point where the handrail disappears into the guide box. 

New handrail drive systems are aimed at providing a significant improvement in ride quality in terms of both vibration and noise. The relationship of handrail to tread speed is carefully calibrated to further improve ride quality.

Dimensional stability is used to refer to the integrity of the handrail profile over the operational life of the product. Essentially, how well the handrail stays true to its form despite thousands of hours going round and round the escalator or moving walk.

An escalator transports people automatically when switched on, with individuals simply standing still. As such, traveling on an escalator requires little physical exertion. Escalators offer plenty of space, too, especially when compared to an elevator or narrow staircase where people may be squashed together.

Safe operation, comfort of travelers, minimum space requirements, less installation and operating costs, aesthetics and regulatory norms are some other very important parameters considered during the design of escalators. In addition, location of the escalator should also be given due importance during planning of escalator system for an area. 

1. departure - отправление

2. freight - груз

3. shipment  - перевозка

4. tare - тара

5. weight - вес

6. wear resistance - износостойкость 

7. batch number - серийный номер

8. bill of entry - ввозная таможенная декларация

9. bulk cargo - насыпной груз

10. escalator - эскалатор

11. cardboard box - картонная коробка

12. cargo - груз

13. load - груз

14. carriage - перевозка

15. carrier - перевозчик

16. certificate of origin - сертификат происхождения

17. clearance - разрешение

18. heavy traffic - интенсивное движение

19. delivery - доставка

20. supply - поставка

21. in bond - в ожидании разрешения

22. handrail  - поручень

23. in transit - транзитом

24. lorry - грузовик

25. truck - грузовик

26. net weight - чистый вес

27. on arrival - по прибытию