This invention concerns an assembly to clamp a rolling ring as set
forth in the main claim.
The assembly to clamp a rolling ring according to the invention is
applied to the field of rolling and, to be more exact, to the clamping of the rolling
rings on ring-bearing shafts of a rolling mill stand.
In rolling mill stands of the state of the art of a type including
ring-bearing shafts cooperating with a rolling ring, the rolling ring is normally
fitted to the respective shaft by positioning in series a labyrinth-type ring
containing an inner channel, the rolling ring, a cap rotatably clamped to the rolling
ring and a closure flange which is associated with the shaft by means of a locking
The rotational clamping of the cap to the rolling ring is normally
ensured by frontal coupling elements of a male and female type which are included
respectively on the opposed surfaces of the cap and of the rolling ring.
A spacer is inserted between the rolling ring and the cap so as to
ensure the presence of a gap therebetween of a desired value and thus to prevent
direct contact between the cap and the rolling ring.
This spacer is fitted to an alignment bush which cooperates with
the rolling ring and with the cap.
In clamping assemblies of the state of the art the spacer is clamped
to the cap by means of a screw thread, this type of clamping entailing a plurality
of problems about which users have complained for a long time.
In particular, where the rolling ring has not been properly installed
during the clamping and unclamping operations, the spacer is stressed in an anomalous
manner with a resulting stripping of the screw thread and with a consequent inability
to re-use the system.
The present applicants have designed, tested and embodied this invention
to overcome the shortcomings of the state of the art and to achieve further advantages.
This invention is set forth and characterised in the main claim,
while the dependent claims describe variants of the idea of the main embodiment.
The purpose of this invention is to provide an assembly for the clamping
of the rolling ring to the ring-bearing shaft whereby the clamping assembly eliminates
the problems linked to incorrect installation and to processing faults.
The clamping assembly according to the invention always ensures the
presence of a required longitudinal gap between the rolling ring and the cap and,
if this gap does not exist, does not cause damage which would render the whole
system unsuitable for further use.
The clamping assembly according to the invention provides for the
use of a spacer having a cylindrical alignment surface which cooperates with the
cap and which enables the spacer to be displaced axially by a determined and required
travel, which is advantageously of a value of some millimetres.
Clamping to prevent accidental withdrawal of the spacer from the
cap during movements without the rolling ring is ensured by at least two radial
keys associated with the elements providing frontal coupling of the cap and protruding
towards the axis of the ring-bearing shaft, these keys are solidly fixed to the
cap by clamping screw means.
The protruding part of the keys cooperates with mating seatings machined
in a coordinated position on the outer surface of the spacer.
Moreover, the clamping assembly according to the invention includes
wear-resistant bearing rings between the labyrinth ring cooperating with the rolling
ring and the ring-bearing shaft so as to prevent any sliding being able to damage
the ring-bearing shaft, above all during the beginning of the rolling of a new
The attached figures are given as a non-restrictive example and show
a preferred embodiment of the invention as follows:-
- shows a longitudinal section of a clamping assembly according to the invention
as fitted to a ring-bearing shaft;
- shows in an enlarged scale the detail "A" of Fig.1;
- shows a partial longitudinal section of the clamping assembly of Fig.1 at the
clamping means between the rolling ring and the cap;
- is a view of the clamping assembly along the line B-B of Fig.3;
- is a three-dimensional diagram of the rolling ring and the cap in their disassembled
The reference number 10 in the figures denotes a rolling ring associated
with a ring-bearing shaft 11 of a rolling mill stand, which is not shown here.
The rolling ring 10 cooperates with a clamping assembly 12, which
ensures longitudinal and rotational clamping of the rolling ring 10 to the ring-bearing
shaft 11 and which ensures at the same time a ready installation/dismantling of
the rolling ring 10.
The clamping assembly 12 according to the invention comprises a labyrinth-type
ring 13 containing an inner channel, a spacer 14, a cap 15, a closure flange 16,
a locking screw 17 and a tapered alignment bush 18 cooperating both with the rolling
ring 10 and with the spacer 14 and cap 15.
In this case, the labyrinth ring 13 cooperates with a wear-prevention
spacer 27, which abuts against a ledge 28 of the ring-bearing shaft 11 and includes
between the labyrinth ring 13 and the ring-bearing shaft 11 a bearing 22 having
the function of a wear-prevention ring.
The spacer 27 and the bearing 22 may be associated with each other
also to form one single body.
The rotational clamping of the cap 15 to the rolling ring 10 is ensured
by frontal male coupling elements 30, which are included on the surface of the
cap 15 and which cooperate with mating female elements 31 included in the opposed
surface of the rolling ring 10.
In this case, each of the frontal male 30 and mating female 31 coupling
elements comprises two diametrically opposed elements, as shown diagrammatically
In the clamping assembly 12 according to the invention the cap 15
has a cylindrical alignment surface 19 including a frontal abutment surface 33
which abuts against the spacer 14.
The spacer 14 includes packings 34 cooperating with a first chamber
35 machined in the cap 15 in cooperation with the alignment bush 18.
In a second chamber 37 machined in the cap 15 is lodged also a head
36 of the alignment bush 18, this head 36 too being equipped with relative packings
Pins 38 cooperate with the head 36 and clamp the alignment bush 18
mechanically in the clamping position.
A first feeder conduit 39 cooperates with the first chamber 35, while
a second feeder conduit 32 cooperates with the second chamber 37.
The spacer 14 includes abutment means 40 that cooperate with the
rolling ring 10.
The clamping assembly 12 according to the invention comprises also
rotation-prevention means 20 between the tapered alignment bush 18 and the cap
15. In this case the rotation-prevention means 20 include a tooth 21a associated
with the inner surface of the tapered alignment bush 18, this tooth 21a being
engaged with a mating tooth 21b located in a coordinated position on the cap 15.
So as to prevent accidental withdrawal during movements without a
rolling ring 10, the spacer 14 in the clamping assembly 12 according to the invention
is clamped to the cap 15 by keys 23 positioned in seatings 24 machined in the male
frontal coupling elements 30 and including a protruding part 23a facing towards
the axis of rotation of the ring-bearing shaft 11.
This protruding part 23a cooperates with a seating 25 of a mating
form machined in the spacer 14 so as to ensure reciprocal circumferential clamping
that permits longitudinal sliding of the spacer 14.
Each key 23 is associated with the cap 15 by means of a fixture screw
26, which, in the event of incorrect functioning or clamping, breaks and thus prevents
more severe damage.
During the installation step the distance between the frontal abutment
33 and the abutment means 40 has the effect that a first longitudinal gap 29a of
a required value is always present between the opposed surfaces of the rolling
ring 10 and of the cap 15; a second gap 29b is also present between the frontal
coupling elements 30, 31.