RU42448U1 - SUPPORT FOR ROLLING ROLLER - Google Patents

Abstract

The utility model relates to rolling production, in particular, to equipment for hot rolling of plate steel. The main goal solved by the utility model is to increase productivity and reduce production costs by extending the campaign of roll bearings of a reversing plate mill. The proposed support of the rolling roll of the said mill comprises a pillow and a cylindrical liner in contact with the neck of the roll, on the working surface of which from the output side are made two rows of holes of a given depth parallel to the longitudinal axial plane of the roll and staggered in which the rods are installed made of MoS of a given diameter and differs in that identical holes with MoS rods are made on the input side of the insert, with all the holes located sym ternally and parallel to the axial longitudinal plane of the roll, the minimum distance between opposite rows of holes is (0.77-0.79) R, where R is the radius of the neck of the roll, the distance along the axis of the roll between adjacent holes of adjacent rows is equal to the diameter of the rods and half the same distance between holes of one row, and the total area of the rods on the working surface of the liner is (0,035-0,036) F, where F is its area.

Description

The proposed utility model relates to the processing of metals by pressure and can be used in the production of hot-rolled plate.

Such steel with a thickness of more than 4 mm can be rolled on sheet mills containing the Trio stand (with three rolls having barrels of the same or different diameters).

The end parts (necks) of the rolls of the Trio stands are installed in open plain bearings, which consist of pillows-bearings with cylindrical inserts placed in them, in contact with the necks and made, for example, of textolite. The designs of whole-stamped inserts are described in sufficient detail in the book of A.I. Tselikov and V.V. Smirnov “Rolling Mills”, M., Metallurgizdat, 1958, pp. 73-78. Closed or through grooves for lubrication are often made on the inner (working) surface of the liners.

Open plain bearings are simple to manufacture and operate and can withstand significant loads when rolling thick sheets.

A support of a rolling roll of a non-reversible mill is known, comprising a pillow and a cylindrical liner, on the working surface of which a closed lubricating groove is made from the input side, and at specified distances from the longitudinal axis of the liner there are two additional grooves filled

anticorrosive material (see AS USSR No. 1581396 class. In 21 In 31/02, publ. In BI No. 28, 1990).

However, such a support is unsuitable for operation on a reversing mill, where the direction of rotation of the rolls is constantly changing, due to the insufficient duration of its operation.

The closest analogue to the claimed object is the support of the rolling roll described in the patent of the Russian Federation for a utility model (decision on the issuance of application No. 2004104813 class B 21 V 31/02 with priority dated February 18, 2004).

This support of the rolling roll of a non-reversible plate mill contains a pillow and a cylindrical liner in contact with the neck of the roll and is characterized by the fact that a closed lubricating groove is made on the input side of the working surface of the liner, and on the output side there are two rows of holes of a given quantity, diameter and depth at a certain position on the surface of the liner, in which rods of disulfide-molybdenum (MoS ₂ ) are installed at the level of said surface.

The disadvantage of this design of the support is also its unsuitability for work on a reversing mill due to insufficient wear resistance.

The technical task of the proposed utility model is to extend the working campaign of the roller bearings of a reversing plate mill, thereby increasing its productivity and reducing production costs.

To solve this problem, a support of a rolling roll containing a pillow and a cylindrical insert in contact with the neck of the roll, on the working surface of which two rows of holes are made from the output side

of a given depth parallel to the longitudinal axial plane of the roll and staggered in which rods of MoS _{2 of a} given diameter are installed, identical holes are made on the input side of the insert with rods of MoS ₂ , while all holes are symmetrically and parallel to the axial longitudinal plane of the roll, the minimum distance between opposite rows of holes is (0.77-0.79) R, where R is the radius of the roll neck, the distance along the roll axis between adjacent holes of adjacent rows is equal to the diameter of the rods and half the same distance between the holes of the same row, and the total area of the rods F _c on the working surface of the liner is (0,035-0,036) F, where F is the surface area of the liner.

The given relations of the support parameters are obtained during the processing of experimental data and are empirical.

The essence of the proposed technical solution is to optimize the location of the rods of MoS ₂ and specify their total contact (with the neck of the roll) area, which allows to reduce the coefficient of friction of sliding between the neck of the roll rotating in one direction or another. As a result of this, the working campaign of the roll bearing of the reversing mill is extended with the above positive consequences.

Since when rolling thick sheets, the maximum of normal stresses from the pressure of the metal on the rolls does not coincide with their longitudinal axial plane, but is shifted towards the exit of the metal from the rolls (see, for example, the book by A. I. Tselikov et al. “Theory of longitudinal rolling” , M., "Metallurgy", 1980, p. 75-80), then

the location of the holes with the rods is removed at a certain distance from the middle of the length of the liner. Obviously, with a variable direction of rotation of the roll, the holes should be located on both sides of the midline of the liner (i.e. from the indicated axial plane) and at the same distance from it.

The proposed support of the rolling roll is shown schematically in figures 1 and 2 (front view and top view).

A cylindrical insert 1 of thickness S is installed in the support 2 of the reverse stand symmetrically to the axial plane YY of the roll. On both sides of the liner and symmetrically to the YY axis, two rows of holes 3 with a diameter d made parallel to this axis are made, and the minimum distance between the opposite rows of 4 holes L _min = (0.77-0.79) R, where R is the radius of the roll neck , i.e. inner radius of the liner. The distance l ₁ along the YY axis between adjacent holes of adjacent rows is equal to the diameter d of these holes (and rods) and half the distance l ₂ between the holes of the same row.

The distances L _min and l _{3 are} measured in a straight line connecting the intersection points of the corresponding radial axes with the generatrix of the working surface 5 of the liner, the total working length L ', which is determined by the values of the angle α and R.

The area of all the rods on the working surface of the liner (their total contact area) is (0,035-0,036) F, where F = L × B, and L and B are the working length and width of the liner, respectively. From the value of F it is easy to find the total required number of rods and holes.

A pilot test of the proposed technical solution was carried out on a plate mill 2350 OJSC "Magnitogorsk Iron and Steel Works".

For this purpose, when rolling steel sheets of various assortments, inserts with holes and rods made of MoS _{2 were used} at their different locations and quantities. The values of d, h, and l ₃ were the same as those of the support of known construction (see above) with the same parameters S, B and L of the liners.

The best results (maximum duration of the support at the highest mill productivity) were obtained during the operation of the inventive support. Deviations from its above parameters worsened these indicators.

For example, a decrease in the total contact area F _{c of the} rods less than 0.035 F accelerated their wear and, therefore, reduced the duration of the support, and when F _c > 0.036 F, this value practically did not increase, but the labor required to manufacture the supports increased.

With the asymmetric (relative to the YY axis - see figure 1) arrangement of holes on the surface of the liners, as well as with a change in L _min (in either direction), the resource of the supports also decreased, obviously, due to the mismatch of the location of the rods with the zone of maximum specific metal pressures by roll. The decrease in the values of l ₁ and l ₂ led to a weakening of the liner, the appearance of microcracks on it and accelerated wear; an increase in l ₁ and l ₂ reduced the total number of rods (and their F _c ), which also reduced the duration of operation of the supports.

Control rolling using a known support showed that the duration of its work in the reversing stand is 1.5-2 times less than that of the claimed one, with a corresponding decrease in mill productivity. So

Thus, an experimental verification confirmed the acceptability of the technical solution found to achieve the goal and its advantages over a known object.

Concrete example

The support of the rolling roll for a reversing stand of a plate mill rolling metal 6-30 mm thick has the form shown in figure 1.

The textolite insert was made with dimensions: S = 40 mm, R = 340 mm, α = 135 °, B = 458 mm, the length of the working surface L = πRα / 180 ° -35 mm = 3.14 × 340 × 135 / 180-35 ≈766 mm; F = B × L = 766 × 458≈350830 mm ² . F _c = 0.0355 F = 0.0355 × 350830≈12450 mm ² . When d = 0,48 S = 0,48 × 40≈19 mm and the contact area of one rod _to f = πd ^2/4 = 3,14 × ¹⁹ February / 4≈284 mm total number of rods is equal to: F _c / f _to = 12450 / 284≈44, i.e. 22 holes on each side of the insert.

Other sizes: h = 0.55 S = 0.55 × 40 = 22 mm; L _min = 0.78 R = 0.78 × 340≈265 mm; l ₁ = d = 19 mm; l ₂ = 2l ₁ = 2 × 19 = 38 mm; l ₃ = 0.15 R = 0.15 × 340 = 51 mm.

The technical and economic analysis carried out at OJSC MMK shows that the use of the proposed support for reverse rolling of thick plates increases its service life by at least 1.5 times with an increase in productivity of about 7% and a reduction in labor costs of at least 5%.

Claims (1)

A support of a rolling roll of a plate mill, comprising a pillow and a cylindrical liner in contact with the neck of the roll, on the working surface of which, on the output side, two rows of holes of a given depth are made parallel to the longitudinal axial plane of the roll and staggered in which the rods are installed of molybdenum disulfide of a given diameter, characterized in that on the input side of the liner there are identical holes with disulfide-molybdenum rods, while e holes are located symmetrically and parallel to the axial longitudinal plane of the roll, the minimum distance between opposite rows of holes is (0.77 ÷ 0.79) R, where R is the radius of the neck of the roll, the distance along the axis of the roll between adjacent holes of adjacent rows is equal to the diameter of the rods and half the same distance between the holes of the same row, and the total area of the rods on the working surface of the liner is (0,035 ÷ 0,036) F, where F is the surface area of the liner.