TPT September 2012

94 / 156

Technology News
92 September 2012
A number of solutions for the
revamping of cold rolling mills
EZTM JSC has developed a number
of solutions for the revamping of cold
rolling tube mills of the third model,
including the facilitated stand DUO with
vertical roll configuration, with the ring
dies provided with single-side drive.
Due to the stand design, the
combination of centre-to-centre distance
between work rolls and pinion gear
mounted is in accord with the optimal
mangling diameter. This minimises the
rolling axial force that in return affects
the quality of the produced tubes, the
stability of rolling process, reduction of
wear of pinion gears and racks and also
provides the possibility of multiple-use
of worn-out dies due to their regrinding.
The use of ring dies provides the
possibility to reduce overall dimensions
of the stand, decrease its mass (by 1.5
times) and reduce the loads on the drive
mechanism. Roll changing is performed
by the assembly rolls and takes not
more than one hour.
The technical solutions, implemented
in the suggested design, allow increased
accuracy of rolled tubes; decreased
loads on the mill mechanisms to increase
their durability; increased die life;
reduced roll changing time; increased
number of strokes of the stand (due to
the decreasing of its mass) when the
loads on the drive are the same, and as
a consequence increased capacity; and
improved work conditions.
EZTM JSC has gained experience in
using mechanisms with the planetary
crank conversion device of the continuous
rotation into interrupted (impulse) one.
The values of maximum forces in the
links of such sizes are 3-4 times less than
in some other types of mechanical feed
mechanisms. The exact feed and turn
of the tube by the new mechanism are
provided by firm kinematical connection
of the impulse turn of its output links
(connected with the transmission of the
turn and lead screw) with the continuous
rotation drive through the device.
Providing the mill with the mechanism
with the planetary conversion device
allows the implementation of the rolling
scheme with the feed and turn in both
end positions of the work stand (double
feed and turn), which allows it to divide
feed and increase the total feed, to
increase the mill capacity.
The use of feed and turn mechanisms
allows increased accuracy and
configuration of produced tubes; and
increased total feed for double stand
stroke due to the usage of the rolling
scheme and increased capacity.
EZTM JSC – Russia
Website: