Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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ROLLING MILL ROLL ASSEMBLY
BACKGROUND OF THE INVENTION
1, Field of the Invention
This invention relates generally to rolling mills, and is concerned in
particular with an
improved roll assembly of the so called "overhung" type, in which ring-shaped
roll discs with
cylindrical bores are' centered on tapered shaft sections by nr~eans of
tapered sleeves tightly
wedged therebetween.
2. Description of the Prior Art ' ,
In a known roll assembly of the above-mentioned type, as described in U.S.
Patent No.
5,934,131 (Shen), the tapered sleeve is urged into its operative wedged
position by a rigid
circular retainer. The retainer is rotatably fixed to the shaft, and is
advanced against the sleeve
by torquing a nut threaded onto the end of the shaft. Screws carried by the
retainer are then
tightened against an outboard flank of the roll to urge an inboard flank of
the roll against a
shaft shoulder. When thus tightened, the screws provide the primary means of
transmitting
torque from the roll shaft to the roll.
There are several drawbacks to this arrangement. First, the tapered sleeve may
not be
fully wedged into its operative position prior to tightening of the retainer
screws against the
outboard roll flank. Thus, the roll will not be properly centered on the roll
shaft. Secondly,
the outboard roll flank can be damaged by the torque transmitting retainer
screws.
The objective of the present invention is to provide an improved roll assembly
which
overcomes these drawbacks.
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SUMMARY OF THE TNVENT10N
A roll assembly in accordance with the present invention includes a support
shaft with a
tapered section leading from an abutment to an end section, and a ring shaped
roll with inboard
and outboard flanks and a cylindrical bore. The roll is axially mounted on the
shaft with its
inboard flank seated against the shaft abutment and with its cylindrical bore
surrounding the
tapered shaft section: A tapered sleeve is inserted between the tapered shaft
section and the
cylindrical roll bore. A load ring is rotatably fixed with respect to and
axially shiftable on the
shaft end section on the outboard side of the roll.
A resilient element is interposed between the sleeve and the load ring to
yieldably
maintain an initial gap between the load ring and the outboard flank of the
roll, and a roll
retainer is mounted on the shaft end section outboard of the load ring. The
roll retainer acts in
an abutting relationship with the load ring and via the resilient element to
gradually and at least
partially close the gap hetween the roll and load ring while gradually and
precisely urging the
sleeve into its wedged position. Screw members threaded through the roll
retainer are then
torqued to urge the load ring against the outboard flank of the roll, which in
turn urges the
inboard flank of the roll against the shaft abutment.
These and other features, advantages and objectives will now be described in
greater
detail with reference to the accompanying drawings, wherein:
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BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a vertical sectional view taken through a rolling mill roll
assembly in
accordance with the present invention;
Figures 2A-2D are sectional views depicting successive stages in the
installation of the
roll assembly shown in Figure 1;
Figure 3 is a perspective view of the resilient element interposed between the
tapered
sleeve and the load ring; and
Figures 4 and 5 are horizontal sectional views taken respectively along lines
4-4 and 5-
5 of Figure 1.
DESCRIPTION OF PREFERRED EIvIBODIMENT
With reference initially to Figures 1 and 3-5, a roll assembly in accordance
with the
present invention is generally depicted at 10 . The roll assembly comprises a
support shaft 12
having a tapered section 14 leading from an abutment 16 provided by a pair of
flingers 18a,
18b to an end section 20. The shaft end section 20 is externally splined as at
22 and threaded
as at 24. A ring shaped roll 26 has inboard and outboard flanks 28, 30,
external grooves 32,
and a cylindrical bore 34. The roll 26 is axially mounted on the shaft 12.,
with its inboard
flank 28 seated against the abutment 16, and with its cylindrical bore 34
surrounding the
tapered shaft section 14.
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A tapered sleeve 36 is inserted between the tapered shaft section 14 and the
cylindrical
bore 34 of the roll 26. The outboard end of the sleeve is internally splined
as at 38 for
mechanical interengagement with the external splines 22 of the shaft end
section 20.
A load ring 40 is received on and is axially shiftable with respect to the
shaft end
section 20. The load ring is rotatably fixed to the shaft by means of internal
splines 42 coacting
in mechanical intererigagement with the external shaft splines 22. A disc
spring 44 is captured
in an internal recess of the load ring by means of a spring retainer 46 held
in place by a snap
ring 48,
A roll retainer SO is thxeaded onto the end section 20 of the roll shaft. Sack
bolts 52.are
threaded in through bores containing thrust buttons 54.
The roll assembly is installed in stages as depicted by the following
drawings:
Figure 2A
The roll 26 is mounted on the shaft end section 20 with its inboard flank 28
in contact
with the abutment 16, and with its cylindrical bore 34 surrounding the tapered
shaft section 14.
The tapered sleeve 36 is inserted without a radial interference fit between
the roll bore 34 and
the shaft section 14.
Figure 2B
The load ring 40 is mounted on the shaft end section 20, with its internal
splines 44
interengaged with the external splines 22. The disc spring 44 coacts via the
spring retainer 46
with the outboard end of the sleeve 36 to yieldably maintain a gap 56 between
the load ring
and the outboard flank 30 of the roll.
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Figure 2C
The roll retainer 50 . is threaded onto the shaft end section 24 and torqued
to compress
the disc spring 44 to an extent sufficient to partially close the gap 56, with
the resulting
resilient force being sufficient to create an interference fit between the
tapered sleeve 36 and
the roll bore 34 and tapered shaft section 14. At this juncture, therefore,
the roll is precisely
centered on the shaft.
Figure 2D
The jack bolts 52 are torqued to urge the load ring 40 against the outboard
flank 30 of
the roll 26, which in turn results in the 'inboard roll flank 28 being urged
against the abutment
16.
In light of the foregoing, it will now be understood that prior to torquing
the jack bolts
52, the tapered sleeve 36 is firmly seated with an interference fit between
the cylindrical roll
bore and the tapered shaft section. This insures that the roll is precisely
centered on and
aligned axially with the roll shaft. Torquing the jack bolts then completes
the installation by
axially clamping the roll between the shaft abutment and the load ring, the
latter being in
annular area contact with the outboard roll flank. This reliably transmits
torque from the roll-
shaft to the roll without resulting roll damage.
I claim:
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