Our enterprise manufactures housingless stands of the horizontal and vertical types.
Compared to traditional design such stands have increased stiffness. It allows to increase quality of rolled product. As a result of installation of two lines of vertical stands 320 after a linear mill (Serovsky metallurgical plant) rolled product cross-sectional accuracy was 0,4 mm per Ø 16…22 mm. Replacing the linear mill stands with the new housingless ones allows to achieve rolled product accuracy within the limits of 0,2 mm.
Upon customer request, the stands can be equipped with monitoring system. This system allows to monitor technical condition of the main equipment and the stand itself, to forecast emergency situations and to replace defective units. Besides, customer can control power parameters when going to new standard sizes.
Several years of commercial experience have clearly demonstrated that the use of monitoring systems in rolling process allows to reduce maintenance costs.
EZTM JSC is able to deliver auxiliary equipment including disassembly, assembly and turning and bearing rings removing stands.
Housingless stands
Technical data
|
Parameters |
Stands |
|||
|---|---|---|---|---|
|
620 |
480 |
380 |
320 |
|
|
working roll diameter, mm |
550-620 |
440-480 |
340-380 |
290-320 |
|
working roll length, mm |
400 |
700 |
700 |
600 |
|
working roll neck diameter, mm |
320 |
260 |
220 |
180 |
Horizontal housingless stand
Horizontal housingless stand (see Fig. 1) consists of a working stand 2 (see Fig. 2) and a moving beam 3 with a spindle carrier, a combined gearbox 4 connected with the working stand 2 via gear-type spindles 5 mounted on a single base 1. The gear-type spindles 5 are mounted inside hollow output shafts of the combined gearbox 4 that leads to the spindle length extension and oblique angle arisen fr om rolls gap changing reduction. A gear coupling 6 is mounted on a high speed input shaft of the combined gearbox 4 for connection with a main drive motor.
Vertical housingless stand
Vertical housingless stand (see Fig. 3) consists of a working stand 2 (see Fig. 4) and a combined gearbox 3 connected with the working stand 2 via gear-type spindles 4 mounted on a single base 1. The gear-type spindles 4 are mounted inside hollow output shafts of the combined gearbox 3 that leads to the spindle length extension and oblique angle arisen from rolls gap changing reduction. A gear coupling 5 is mounted on a high speed input shaft of the combined gearbox 3 for connection with a main drive motor 6
Working stand rolls assembly
Working stand rolls assembly (see Fig. 5,6,7,8) consists of two rolls 2 mounted on four-row bearings 2 in roll chocks 3 with thrust block 4 for axial adjustment of the roll. Each chock 3 has a bore wh ere nuts 5 and 6 with different thread directions connected with tightening screws 7 are mounted. Spherical foot bearings 8 are mounted between the nuts and the chocks supporting surfaces in such a way to center each chock on the screws via the spherical bearings 9. It leads to self-adjustment of the chocks 3 and the bearings 2 along the bent axle of the roll during the rolling process.
Nuts 10 with springs 11 tightened with sleeves mounted on the chocks 3 are mounted on the threaded ends of the screws. It leads to balancing of the rolls assemblies with constant force adjusted during their assembly.
Double reduction gearboxes 12 with a motor intended for the rolls gap adjustment are mounted on the upper ends of the screws 7. Rolls gap adjustment mechanism is equipped with a limb for its visual monitoring.
Basic requirements to the working stand monitoring system
Working stand of a small section mill is a complex unit that has a lot of input and output parameters.
Problems solved by the monitoring system
- detection of mechanisms performance
- forecast of technical condition and operational life of the equipment
- record of operating modes of the equipment and power parameters of the rolling process
Upon customer request the monitoring system may record and display the following information:
- motor torque of each stand
- top and spindle torque
- roll force of each stand
- input and output metal temperature for each stand
- temperature of the main gear bearing assemblies and the rolls assemblies of each stand
- information about vibrations in the bearing assemblies, their technical condition and operating life
The monitoring system can provide
- daily record of rolled metal (according to standard sizes and pieces)
- collection and primary processing of inspection sensors signals (rolling process)
- collection and primary processing of inspection sensors signals (equipment condition)
- record, display and audio (light) alarm of preset parameters overrun (rolling process)
- record, display and audio (light) alarm of preset parameters overrun (equipment condition)
- forming and display (printing) of signals status protocol
- forming of monitored data store 10 sec. before "Alarm" signal and 2 sec after the main drive emergency shut down
- record of daily average and max monitored rolling parameters for each strip and their display (printing) upon operator request
This is a two-level monitoring system
- the upper level is intended for collection and processing of information from subsystems of the low level, system filing and forming of output documents for the staff
- the low level includes several subsystems and is intended for temporary storing of information and its transmission to the upper level
Upon customer request stationary monitoring system of all finishing train including sensors installation and information displaying in a control panel can be delivered. Besides it is possible to phase this system in.