90m finishing mill group

The purpose of the equipment

The finishing mill group is composed of top crossed 45° high-speed wire-rod finishing mills.

The finishing mill group is located in high-speed wire-rod workshop. Through 10 unit rack the continuous micro-tension rolling mill will be transported upstream Æ17 ~ Æ21mm of rolling, rolling become Æ5.5 ~ Æ16mm finished wire. The working speed of 90m/s is insured. The specification of end product is Æ5.5mm.

Structural characteristics of finishing mill

l  Finishing mill unit is combined with ten mills, speed increasing box, support base, arc coupling, waterproof slot, waterproof plate, the protective cover, piping and guide of finishing mill. Mill frame is composed of three Æ200mills and seven Æ150 mills, frame use top crossed 45° composition form to achieve no twisting, no contact axis, little axis and shock for equipment, besides, it decrease the center of gravity height, the stability increased as well, in the mean time, the total weigh has decrease and it is easy to maintain. Ten frames are concentrated transmission.

l  Roll frame is composed of roller box, bevel gearbox and spare parts of bevel gearbox.

l  Roller box and bevel gearbox adopt outside combinational instruction, decrease the size of bevel gearbox to decrease the weight of finishing mill, decrease the space of mills to make their structure compact. Roller box used cantilever roll loop, there is eccentric locking collar in the box to adjust roll gap. Film bearing and roll shaft are inside eccentric locking collar , taper sleeve is used to fix roll loop which is in the end of roll shaft.

l  Bevel gearbox is composed of box, transmission box, spiral bevel gear roll and synchronized gears. All gears are hardened grinding gear, geartooth correction is needed. The accuracy level of spiral bevel gearbox is six and round bevel gearbox is five to insure the smooth working of high speed.

l  Roller box and bevel gearbox are connected by bolts, a part of roller box plug into the bevel gearbox to let two synchronized gears in bevel gearbox meshed. Roller box and bevel gearbox are fixed by two locating pin, the roller box with same specification can be changed.

l  The axial force of the roll shaft beared by a pair of thrust ball bearings , this ball bearing mounted on the axial clearance in the absence of the resilient washer, because the very small axial clearance ball itself, therefore the roll shaft to accurately positioned in the axial direction, which ensures accurate roll rolling precision, which is to ensure the dimensional accuracy of the workpiece.

l  The roller shaft near the film bearing is designed in the form with taper, so the roller shaft can bear uniform load distribution even it is bend. So the lifetime of roller can be improved.

l  The adjustment of roll gap is to rotate feed screw with left and right thread and nut. When the two eccentric rotated relatively, the distance of two rollers changed with the symmetrical eccentric relative movement of eccentric locking collar, so the location of former roller line and guide can be maintain.

Roller loop is tungsten carbide, it is connected on the cantilever roll shaft, we use the specific hydraulic changing roll equipment to replace roll loop, it is convenient and easy.

l  Equipment performance

1, parameters

2, Equipment performance

The form of mill: Cantilever roller loop mill

The quantity of frame: ten (first~fifth frame are Æ200 mill,sixth~tenth frame are Æ150mill)

Design method:  top crossed 45°, ten frames concentrated transmission.

Size of roll loop:   Æ200 mill:(Æ210.5--Æ189.5)×Æ120.65×72mm

Æ150 mill:(Æ158.8-Æ142.9)×Æ87.76×62mm

Strength of rolling:     Æ200 mill:152kN

Æ150mill:107.8kN

Space of rolling:   Æ200 mill:2.86kNm

Æ150 mill:1.61kNm

Transmission motor:  DC motor

                  Power: 1600kW×three or 4500 kW AC inverter motor

                   Rotating speed: 1000~1300 r/min

                   Working rotary speed: 900~1100r/min

The speed ratio of mill group:

Lubrication: thin oil concentration lubricated

            System oil pressure: 0.35~0.6MPa

            Consumption: 1500L/min

            Oil: Mobil 525

 Cleanliness: 10m

           Cooling for roll: water pressure: 0.6MPa

           Consumption: maximum is 10´30m3/h

           Hydraulic pressure system of protective cover:

           Working pressure: 20MPa

           System flow:  35 l/min

           Composition of machine: Æ200 mill(three),Æ150mill(seven), guild fittings, speed increasing box, support base, flap, waterproof slot, buffer tank, the protective cover, couplings and pipework of finishing mill.