It consists of a roller, a roller bearing, a frame, a rail seat, a roller adjusting device, an upper roller balancing device and a roller changing device.

roll

It is a part that plastically deforms metal (see roller).

roller bearing

Support the roller and keep it in a fixed position in the frame. Roller bearings have heavy working load and great changes, which require small friction coefficient, sufficient strength and stiffness, and convenient replacement of rollers. Different types of roller bearings are selected for different rolling mills. Rolling bearings have high rigidity and low friction coefficient, but low bearing capacity and large overall size, and are mostly used as work rolls of strip mills. There are two kinds of sliding bearings: semi-dry friction and liquid friction. Semi-dry friction roller bearings are mainly bakelite, copper tile and nylon tile bearings, which are relatively cheap and are mostly used in profile rolling mills and cogging machines. There are three kinds of liquid friction bearings: dynamic pressure, static pressure and dynamic and static pressure. The advantages are relatively small friction coefficient, large bearing capacity, high working speed and good rigidity, while the disadvantage is that the oil film thickness changes with the speed. Liquid friction bearings are mainly used as backup rolls for strip mills and other high-speed mills.

mill housing

It is composed of two "arches" for installing the roller bearing seat and roller adjusting device, and it needs enough strength and rigidity to bear the rolling force. There are two main types of racks: closed and open. Closed stand is a kind of integral stand with high strength and rigidity, which is mainly used for blooming mill and strip mill with high rolling force. The open frame consists of a frame body and an upper cover, which is convenient for changing rolls and is mainly used for horizontal profile rolling mills.

In addition, there are rolling mills without arches.

Rolling mill rail seat

Used to install the frame and fix it on the foundation, also called the baseboard. Bear the gravity and tilting moment of the working base to ensure the accuracy of the installation size of the working base.

Roller adjusting device

Used to adjust the roll gap to make the rolled piece reach the required section size. Upper roller adjusting device, also known as "pressing device", has three types: manual, electric and hydraulic. Manual screwdown devices are mostly used in profile rolling mills and small rolling mills. The electric screw-down device comprises a motor, a reducer, a brake, a screw-down device, a nut screw-down device, a position indicator, a spherical pad and a pressure gauge; Low transmission efficiency, large moment of inertia of moving parts, slow response speed and low adjustment accuracy. Since the 1970s, AGC (Automatic Thickness Control) system has been adopted in strip mills, and hydraulic screwdown devices have been adopted in new cold-rolled strip mills and heavy plate mills, which have the advantages of small plate thickness deviation and high product qualification rate.

Upper roller balancing device

A device for lifting the upper roll and preventing the rolled piece from being impacted when entering or leaving the roll. Its forms are: spring type, commonly used in profile rolling mill; Heavy hammer type, often used in blooming mills with large roll movement; Hydraulic type, often used in four-high strip mill.

In order to improve the operation rate, it is required that the roll change of rolling mill is fast and convenient. There are four roll changing methods: C hook type, sleeve type, trolley type and whole frame roll changing type. The first two methods are crane-assisted roll change, while the whole roll change requires two sets of racks. This method is mostly used in small rolling mills. Car roll changing is suitable for large rolling mills and is beneficial to automation. At present, the rolling mill adopts a fast automatic roll changing device, and it only takes 5 ~ 8 minutes to change the roll once.

gearing

It consists of a motor, a reducer, a gear seat and a connecting shaft. The gear seat distributes the transmission torque to two or more rollers.

Auxiliary equipment includes a series of auxiliary processes in the rolling process. Such as raw material preparation, heating, steel turning, shearing, straightening, cooling, flaw detection, heat treatment, pickling and other equipment.

Manipulate handiwork

Cranes, transport vehicles, roller tables and transfer machinery.

ancillary equipment

There are power supply, power distribution, roller grinding, lubrication, water supply and drainage, oil supply, compressed air, hydraulic pressure, mill scale removal, machine repair, electrical repair, acid drainage, oil-water acid recovery and environmental protection.

Rolling mill terminology

Named according to rolling variety, rolling mill type and nominal size. For profile rolling mill, the principle of "nominal size" is named after the pitch diameter of herringbone gear on the gear seat; For the blooming mill, it is named after the nominal diameter of the roll; For strip mill, it is named after the length of work roll; For the steel pipe factory, it is named after the largest pipe diameter produced. Sometimes named after the inventor of the rolling mill (such as the Sendzimir mill).

Selection of rolling mill

According to the requirements of product variety, specification, quality and output, select the type and size of finished or semi-finished rolling mill, and equip it with necessary auxiliary, lifting, transportation and auxiliary equipment, and then make a balanced selection according to the requirements of various factors.

Power facilities of rolling mill

1590, Britain began to use water turbines to drive road rollers. Until 1790, there were still four-high steel plate mills driven by water turbines with stone flywheels (Figure 4: steel plate mills driven by water turbines). 1798, Britain began to use steam engines to drive rolling mills. Modern rolling mills are all driven by DC or AC motors, either by a single machine or by a group of gears.

Classification of rolling mills

Rolling mills can be classified according to the arrangement and number of rolls, the arrangement of stands and the products produced, which are listed in Table 1, Table 2 and Table 3 respectively.

Development of rolling mill

The development trend of modern rolling mill is continuity, automation and specialization, with high product quality and low consumption. Since the 1960s, great progress has been made in the design, research and manufacture of rolling mills, which have improved the performance of strip cold and hot rolling mills, thick plate rolling mills, high-speed wire rod rolling mills, H-beam rolling mills and continuous pipe rolling mills, and a series of advanced equipment such as wire rod rolling mills, fully continuous strip cold rolling mills, 5500mm wide and thick plate rolling mills and continuous H-beam rolling mills have emerged. The single weight of raw materials used in the rolling mill has increased, the hydraulic AGC, shape control, electronic calculator process control and detection means have become increasingly perfect, and the rolling varieties have been continuously expanded. Some new rolling methods, such as continuous casting and controlled rolling, and rolling mills with special structures to meet new product quality requirements and improve economic benefits are being developed. (Check the production site of continuous rolling mill in Angang blooming mill, billet sizing equipment -2000-ton shearing machine, slab rolling in blooming mill, tapping in soaking pit of blooming mill in Shanghai No.5 Iron and Steel Plant, domestic 4200mm thick plate mill, hot leveler for wide and heavy plate, high-pressure descaler before roughing mill, 2300mm steel plate mill, 6500mm steel plate mill production site, control room of 38+0700 mm hot continuous rolling mill and cold strip. Hot-dip galvanizing line for strip steel, H-type wide-edge I-beam rolling mill, medium-sized rolling mill, and main methods for cutting profiles to length ── hot saw, rail cooling bed for large-scale rolling mill, coil cooling to ensure wire performance, newly-built 45-degree untwisted finishing mill and small-scale rolling mill. The important auxiliary equipment of in-line small rolling mill, the finished product receiving equipment of wire rod mill-coiler, automatic pipe mill for rolling seamless steel pipe with diameter of 1.40mm, large diameter steel pipe with diameter of 2,540mm manufactured in 1970s, large diameter spiral welded pipe, one of modern pipe-making methods, straightener for ensuring the dimensional accuracy of steel pipe in seamless steel pipe factory, and seamless steel pipe billet are being punched and rolled. Working scenes of Sendzimir's 20-roll aluminum foil mill, train wheel and tire mill, domestic large-scale forging equipment-32,000-ton hydraulic press, new plastic processing equipment-precision forging press, 3,000-ton horizontal extruder, aluminum foil mill, various rollers for rolling various products, and aluminum continuous casting machine.