Note: Descriptions are shown in the official language in which they were submitted.
1311377
-- 1 --
This invention relates to forming rolls used in
metal forming and in particular to the supportinq
mechanism for the bearing arrangement used to
rotatably mount the large, heavy rolls, commonly
called back-up and work rolls.
It is well known to mount a main roll of a
rolling mill in top and bottom chalks in which are
mounted suitable bearings. At the outboard and
inboard end of the bearings are provided collars. In
one known arrangement, the outboard collar has a
bearing retainer extending around its circumference,
which retainer is held in place by bolts threaded
into the chalks. A thrust collar bears against the
axial outer face of the outboard collar. Extendin~
about the inboard collar is a seal rin~ that is
mounted by bolts to the chalks.
It is also known to use plane bearin~s (usually
babbit) to rotatably support the large rolls in a
rolling mill. These bearings which use a large
quantity of oil in order to operate can be used in
conjunction with tapered roller bearin~s mounted
axially outwardly from the plane bearin~. The inner
bearing support is held in place hy the use of a
split ring that is threaded on the outside and that
is mounted in a circumferential recess formed in the
roll end.
q~
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1311377
-- 2
The split ring is held in place by a complete
exterior ring having internal threads and it is this
exterior ring that actually bears against the side of
the inner bearin~ support. The end of the roll and
its exterior ring are covered by a protective cap.
This arrangement for mounting bearings on the end of
the rolls has several inherent disadvantages
including the fact that the threads on the rinqs can
be easily damaged and there is a possibility of
injury to workmen because of the known method for
tightening the threaded exterior ring (this method
employs a pin and cable). The known methods for
mounting the bearings is time consuming and it will
be appreciated that it is important to reduce the
downtime for these rolling mills as much as possible
in view of the cost of such mills.
The use of a device known as "a hydraulic nut"
is known in rolling mill construction, particularly
in the construction of prestressed roll stands. The
device can consist of ring-shaped members, namely a
; cylinder and a piston. In one known arrangement in a
rolling mill, one of these members is directly
connected with a tie rod by means of a clamp nut and
is displaced with the ex~ansion of the tie rod under
hydraulic stressin-g, the other member resting against
a support.
13~1377
For example a hydraulic stressing device as shown in
U.S. patent 3,588,044 issued June 2~, 1971 to E.G.
Reichrath and ~.K. ~uchheit. The device taught in
this patent specification consists of a rin~ cylinder
and a ring piston surrounding a tie rod. The piston
is pressed downwardly by means of screw bolts and is
connected directly through a divided ring with the
end of the tie rod by engaging beneath a
protruberance at the end of the tie rod. Fluid
pressure is used to actually expand the tie rod in
order to clamp the components together with a
selected clamping force.
V.S. patent 4,581,911 issued April 15, 1986 to
Y. Shinomoto describes a cantilever-type rolling mill
having a pair of roll shafts rotatably supported in a
roll housing. The rollin~ mill includes a tension
member provided axially through the center of the
roll shaft and havin~ the outer end thereof
projecting out of the roll shaft. There is a roll
compressin~ tool detachably enqageable with the
projecting end of the tension member, which tool
incorporates a hydraulic piston-cylinder. The tool
has a nut member threadably fitted on the outer
periphery of the cylinder. An extraction ring
interlocks the roll unit with the tool. An oil
pressure passa~e in the cylinder communicates with an
; annular groove located at the inner end of the
; piston.
13~37~
-- 4
In order to mount the roll unit, this unit is mounted
on the tool by the use of the extraction ring and
then the unit and the tool are fitted onto the roll
shaft using a jig. Clearly this known hydraulic
piston-cylinder mechanism is not used to hold any
bearing arrangement for the end of the roll in place.
The hydraulic piston-cylinder mechanism or nut
is single acting, that is, it cannot be pressurized
hydraulically in more than one direction. It is
pressurized during the mounting or assembly operation
only and after this operation is completed, the
pressure in this hydraulic nut is removed.
Although it is believed by the applicants that
the use of hydraulic nuts to mount the bearing
arrangement for a roll in a rolling mill has been
proposed in the past, such proposals have not met
with widespread commercial success. Some of these
proposals have been in practice unworkable and because
of the high cost of rolling mills in general, this
industry has been reluctant to accept and adopt new
construction techniques for these mills, at least
until a new construction has proven itself as being a
definite improvement.
A drawing produced by the Timken Company shows
a hydraulic nut arrangement for holding in place a
; tapered four roll T.Q.O. roller bearing mounted on
the reduced end of a work roll. The hydraulic nut is
formed by two ring shaped inner and outer sections.
The outer ring section has a L-shaped cross-section
and it is this section that bears against a further
ring member whose inner end bears against the inner
bearing support.
A
- 5 - 13~1~77
Two ring-shaped seals appear to be provided between
the contacting surfaces of the inner and outer ring
sections that form the hydraulic nut. Another ring
member is mounted on the outer end of the roll to
S bear against the outer end of the inner ring section
and hold the section against axially outward
movement.
According to the present invention, there is
provided a hydraulic fastener for mounting one end of
a roll in a rolling mill stand, which Eastener
includes a hydraulic ring cylinder component having a
one face extending generally perpendicular to the
roll axis and an inner cylindrical surface adapted to
fit onto a reduced diameter end section of the roll.
A chamber extends about the circumference of this
cylinder component and i8 open at the one face. A
hydraulic ring piston component is slidably received
in this chamber and has an inner face. Means are
provided to retain at least a substantial portion of
the piston component in the chamber. There are also
passageway means in the cylinder component for
injecting a hydraulic material into the chamber and
into a space formed between the inner face of the
piston and an opposing face of the chamber. In
addition there are means for retaining the
combination of the cylinder component and the piston
component on the end section of the roll and
zero-leakage, two-directional seals arranged between
the cylinder component and the piston component at
both radially inner and radially outer sides of the
piston.
,.,
A
13~3~7
-- 6
During normal use of the rolling mill, the
hydraulic fastener is maintained under hydraulic
pressure to hold the bearing member in place.
In a preferred embodiment, each of these seals
comprises a filled Teflon seal capable of sealing off
hydraulic material under pressure of at least lO,000
psi. Also, the preferred seals are two directional,
that is, capable of sealing in either of two
directions, for reasons which will be clear from the
following description.
If desired, there can be provided a mechanical
locking device capable of holding the end of the roll
in place in event of failure of the hydraulic
cylinder and piston components. This locking device
includes a locking ring threadably mounted on the
exterior of the ring cylinder.
Further features and advantages will be
become apparent from the following detailed
description of a preferred embodiment taken in
conjunction with the accompanying drawings.
In the drawings,
- Figure l is a horizontal cross-section of a
back-up roll in a rolling mill, which roll i5
provided with plane bearings;
1311377
-- 7
Figure 2 is a detailed view, again in cross
section, of the mounting arran~ement at one end of
the back up roll as shown in Figure 1, which view
shows a hydraulic fastener constructed in accordance
with the invention;
Figure 3 is an end view of the piston used in
the hydraulic fastener of Figure 2, which view shows
the end facing towards the inner bearing support;
Figure 4 is a cross-sectional view of the
piston taken along the line IV-IV of Figure 3;
Figure 5 is an end view of the cylinder
component used in the hydraulic fastener of Figure 2,
which view sho~s the front face directed towards the
roll;
15Figùre 6 is a cross-sectional view of the
cylinder component, which view is taken along the
line VI-VI of Figure 5
Figure 7 is another cross-sectional view of the
' cylinder component taken along the line VII-VII of
Figure 5;
- Figure 8 is an outer end view of a retaining
,; ring used in the hydraulic fastener of Figure 2:
Figure 9 is an inner end view of one half of
the split ring used to mount the hydraulic fastener
of Figure 2;
~. ` .
. .
1311377
-- 8
Figure ln is a right side view of the split
ring component shown in Figure 9.
Figure 11 is an axial cross-sectional view
similar to Figure 2 but illustrating an alternate
version of the invention used in conjunction with
four rows of roller bearings.
Figure 12 is an axial cross-sectional view of
another embodiment shown in a back-up roll
application, which embodiment employs a mechanical
locking device in addition to the hydraulic nut.
Figure 13 is an axial cross-section of another
embodiment of the hydraulic nut, which nut is capable
of removing the bearing for the roll
Figure 14 is an axial cross-section of another
embodiment of the hydraulic nut provided with a
rotatin~ seal and retaining ring located at the
radially outer surface of the nut;
Figure 15 is a cross-sectional detail of a
hydraulic nut illustrating the hydraulics provided to
expand the nut; and
Fi~ure 16 is another cross-sectional detail of
the hydraulic nut of Fi~ure 15 but showing the
hydraulics provided to retract the nut.
Except for the hydraulic fastener of the
present invention used therein, the mountin~
arrangement for a backup roll 10 shown in Figure 1 is
of standard configuration. The particular backup
roll shown employs two plane bearings 12. For
purposes of these bearings the roll ln has a tapered
end section 14 located at each end of the roll. ~ach
1311377
g
end section 14 fits into a tapered bearing sleeve 16.
Each of these plane bearing sleeves is mounted in a
bottom chock lR and a top chock 2n. These chocks are
mounted in roll housing 22 for the operating side of
the roll and roll housing 23 for the drive side of
the roll.
Extending axially outward fro~ each end
section 14 is a generally cylindrical, reduced
diameter end section 24 and fixedly mounted on the
end section 24 is an inner bearing support 26. It
will be understood that the support 26 rotates with
the roll ln. The inner end of the support ~6 rests
against a ring collar 28. There is also an outer
bearing support 3n and between the supports 26 and 3n
are tapered roller bearings 32. The outer bearing
lS support 30 is ~ounted in support ring 34 to which is
attached a circular end plate 36 having an opening
through which extends the reduced diameter end of the
roll 10. Attached to the plate 36 is an end cover 38
which protects the end of the roll and the hydraulic
fastener arranged thereon. The end cover 38 is
detachably connected by means of bolts 40.
Although the present invention as illustrated
in Figure 1 is employed in conjunction with a backup
; roll supported by plane bearings, it will be
appreciated that the present invention can also be
used in conjunction with rolls supported by roller
bearings only. For exa~ple it is known to mount each
reduced end of a roll with 4 rows of roller bearings
and the hydraulic fastener of the present invention
lo - 13~1~77
can be used to support the inner bearin~ support for
these rows of bearin~s. Such an arrangement is shown
in Figure 11 referred to hereinafter. The hydraulic
fastener of the ~resent invention can be used in the
mountin~ of work rolls as well as backup rolls. Also
although Figure l only illustrates the present
hydraulic fastener on the operator side of the roll,
it is also used on the drive side of the roll.
Reference will now be made to the construction
of the roll neck on which the hydraulic fastener 42
of the invention is mounted. The reduced diameter
end section 24 includes an end portion 44 that is
further reduced in diameter. Extendiny around the
end portion 44 i5 a circumferential recess 46 which
separates a head portion located at the very end of
the roll from the remainder of the end portion 44.
The illustrated head portion 48 has the same diameter
as the remainder of end portion 44. In the
illustrated roll, a rounded shoulder 50 is formed
where the end section 24 meets the end portion 44, in
order to prevent stress failure or stress cracking
where the diameter of the roll is reduced.
The principle components of the hydraulic
fastener 42 are shown in Figure 2 in an assembled
condition and these components include a hydraulic
ring cylinder component 52 having a front face 54
directed towards the roll, a hydraulic ring piston
component 56, and a retainer rin~ 58 for retainin~ at
least a substantial portion of the piston 56 in the
cylinder component 56. The component 52 has an inner
cylindrical surface ~0 adapted to fit onto the
reduced diameter end section or end portion 44 of the
- ll 131~377
roll. A chamber 62 extends about the circu~ference
of the cylinder component 52 and is open at the front
face 54.
The preferred piston component 5Ç will now be
described in detail with reference to Fi~ures 3 and 4
The piston has a relatively narrow outer face 64 and
a wider inner face 66. The piston has a cylindrical
surface 68 extendin~ about its interior and extendinq
from a point near the outer face 64 to a point past
the transverse center of the piston. A shoulder 7n
extends radially inwardly from the surface 68 to form
a wide end section 72 of the piston. Located in the
radially inner side of the piston component 56 is a
recess 74 of generally rectangular cross section. A
similar recess 76 is located in a radially outer side
of the piston. Also in the radially outer side of
the p~ston is a further recess 78 that extends to the
outer face 64. The rece~s 78 includes a conical
surface 8n that tapers sli~htly outwardly in the
direction of the inner face 66 and a rounded surface
82 that extends to the radially outer side of the
piston.
Located in the outer face 64 of the piston are
four small holes 84 that are drilled and tapped. The
holes 84 are used to lift the piston component 56 and
mount it in the cylinder component 52. Similar holes
(not shown) are also preferably provided on the axial
outside surface of the cylinder component for the
same reason.
A preferred type of steel for both the piston
56 and the cylinder in which it is mounted is heat
treated 4340 steel. Another type of suitable steel
is 5210n heat treated steel. ~ependin~ upon the
application other types of material may also be used
(such as high strength aluminum).
1 3 1 1 3 1 7
, ~
Prefera~ly the inner corners of the ~iston at R5 and
86 are mitred at a 45 an~le as shown in Fi~ure 4.
Mounted in each of recesses 74 and 7h are
zero-leakage, two-directional seals 88 and 89 which
effectively seal any s~ace hetween the cylinder
component and the piston. Preferably each of these
seals comprises a filled Teflon* seal capable of
sealin~ off the hydraulic material, i.e. grease, used
to operate the hydraulic fastener. A typical minimum
pressure for this grease is 2,000 psi. A
particularly preferred form of Teflon seal is bronze-
filled. Each of the preferred seals 88 and ~9
includes a suitable ener~izer indicated at 9n in
Fi~ure 2 which supports the filled Teflon seal and is
located in back thereof. A preferred ener~izer is
made from Buna-N rubber. Another suitable material
is VITON (trademark) which has the advantage of being
impervious to acids and water. The preferred
bronze-filled Teflon seal mentioned above is
available from Double Seal comPany of Fortworth,
Te~as. The material used in the seal is Model No.
MNM114 or MNM118. Such seals are also available from
Kaydon of Baltimore, Maryland under Model No. K3nT.
The construction of the cylinder com~onent 5~
will now be described with reference to ~igures 5 to
7.
*trade mark
.
1311377
- 13
As indicated above, the component 52 has the chamber
62 extending about its circumference and open at the
front face 54. The chamber 62 is sized to snuggly
accommodate the above described piston component 56.
The depth of the chamber 62 is less than the depth of
the piston component as can be seen from Figure 2.
However the depth of the cylinder component is
greater at the radially outer side thereof, there
being a projecting lip 92 that is threaded on the
radially inner side thereof. The lip 92 thus forms a
circular opening or recess 94 for receiving the
aforementioned retaining ring 58 described further
hereinafter. A small recess 96 is formed in the
shoulder that extends between the edge of the chamber
lS 62 and the lip 92 and this recess accommodates a
static seal such as a Buna N O-ring.
The lip 92 and the radially outer side of the
cylinder form a sloping surface 98 which extends
along a correspondingly sloping surface formed on the
in plate 36 (see Figure 2). Another shorter sloping
surface 100 is formed on the rear face of the
cylinder a short distance from the inner cylindrical
surface 102. The sloping surface lOn provides a
; means for securing a split ring 104 in place as
explained hereinafter.
1311377
- 14
Passageway ~eans are provided in the cylinder
component 52 for injecting a hydraulic material, such
as ~rease, into the chamber 62 and into a space
formed between the inner face of the piston and the
opposinq face ln6 of the chamber 62. A preferred
form of passa~eway is shown in detail in Figure 6.
In particular a passageway 10~ extends fro~ the rear
face of a cylinder to a radially extending passageway
110. At its inner end, the passageway 110 opens into
the chamber 62 immediately adjacent to the bottom lnh
thereof. The radially outer end of passageway lln
opens into the radially outer surface of the
cylinder. ~oth outer ends of passa~eways ln~ and lln
are widened and threaded at 111 and 112 to permit the
attachment of hydraulic fittings. In particular a
charging fitting is attached at 111 and a pressure
relief fitting is attached at 112. Also for~ed about
the outer end of a passaqeway ln~ is a wide circular
recess 114 into which is fitted a cylindrical guard
116 for the fitting. These guards are shown in
Figure 2 of the drawings. It will be understood that
in order to push the piston component out of the
cylinder co~ponent 52, it is Bimply necessary to
force grease through the passageway 1 n~ and the
passageway 110 into the cha~ber 62.
:
,i~ . ,
- 1; - 1311377
~,rease is prevented from passin~ out of the opening
at 112 by the fitting inserted into the openinq 112
except when the pressure exceeds a predetermined
limit. A suitable ~rease for this purpose is
general purpose mill ~rease. Pressures in this
hydraulic nut durinq use thereof can be in excess of
lO,OOn psi.
As indicated in Figure 5 there are three of the
passageways llO for injecting ~rease into the
cylinder to~ether with the accompanyin~ fittin~s.
Two of these are located adjacent one another on one
side of the cylinder co~ponent and the third is
located diametrically opposite one of the other two
pas~a~eways.
Preferably there are also provided passa~eway
means in the cylinder component for injecting
a hydraulic material such as grease into the chamber
62 and into another space 12n, one side of which is
defined by part of an outer face of the piston
component 56. Injection of hydraulic material
through this passageway acts to push the piston
component further into the chamber. This step is
used when it is desired to remove the roller bearinqs
for the roll.
~311377
- 16
This further passaqeway is shown in Fiqure 7 and it
includes a section 122 that is parallel to the
cylindrical surface ln2 and a sloping section 124
that extends from the innermost end of the passaqeway
122 to a corner of the chamber 62. The outer end of
passageway 122 is widened and threaded to accommodate
a grease fitting at 126. The fitting itself is a
standard charging fitting for grease and therefore
has not been illustrated in the drawin~s. Aqain the
ln outer end of the passa~eway 122 is provided with a
relativel~ wide circular recess 128 into which is
fitted a cylindrical guard for the fitting. Again
there are three of the passageways 122 and 124
provided as indicated in Figure 5 of the drawings.
lS Figure 8 illustrates the retaininq ring ~8
which is used to retain at least a substantial
: portion of the piston 5~ in the chamber ~2. This
ring can be made from AISI 4340 steel which has been
quenched and tempered and stress relieved. The rinq
has threads 130 extendin~ about its circumference in
order that it can be threaded into the aforementioned
opening in the front face of the cylin~er.
,.~ ' ,. . . . .
- 17 - 13~1377
These threads should be stron~ enough to he ahle to
withstand a maximum outward hydraulic force on the
piston component. A suitable thread ~or this purpose
is 60 truncated V-thread. Preferably the retaining
ring is locked in place and this can be done by a
lockin~ screw (not shown) that extends through a hole
in the cylinder component 52. Extendin~ about the
circumference of the retaining rin~ and located
centrally on the interior surface is a recess 1~ of
generally rectan~ular cross section. Positioned in
, this recess is a suitable seal 134 to prevent the
hydraulic material from passin~ between the retainer
rin,q and the adjacent side of the piston component
56. ~referably this seal is"~una-N O-rinq seal
provided with a back-up rin~ seal.
Instead of usin~ the illustrated seal 134, the
seal could be a Teflon*-filled seal constructed in
the same manner as the seal 89 described above. This
more expensive type of seal would be used when the
hydraulic fastener is adapted to retract or remove
the roller bearings and their support housin~. This
more expensive seal would not be required when the
hydraulic fastener is not provided with the
retraction capability (an optional feature).
*trade mark
'
- l~ i3~ 1377
The preferred retaining ring 58 has four holes
drilled into the center of its outside surface.
These holes 136 are evenly distributed about the
circumference of the ring and are used to thread the
retaining ring into the cylinder component with a
suitable, known tool. In one embodiment these holes
are 1/4 inch deep and have a diameter of 3/16 inch.
A preferred form of split ring used to secure
the hydraulic fastener on the reduced end of the roll
is shown in Figures 9 and 10. Only the lefthand side
of the split ring is illustrated in these figures but
it will be appreciated that the righthand side of the
split ring is a mirror i~a~e of the illustrated half.
The two halves are bolted together by means of
standard bolts that are not shown in the drawings.
The two bolts on each side extend through bolt holes
140. The illustrated split ring half 142 is attached
to the roll neck in the manner shown in Figure 2
after the hydraulic fastener has been put in place.
The half 142 is generally L-shaped in cross section
with an inward extension 144 defining a cylindrical
surface 146, the radius of which is substantially the
same as the radius of the recess 46 forming the roll
neck. Another interior cylindrical surface 148 has a
radius that is substantially similar to the radius of
the head portion 48 of the roll neck.
- lg 1311377
These two cylindrical surfaces 14fi and 14~ are
separated by a small circumferential groove 150.
A sloping surface 152 extends between the
axially inside face of the split ring and the
radially outer face 154. This sloping surface 1~2
serves an important function in that, in cooperation
with the hydraulic nut, it helps to secure the split
rings firmly onto the roll neck. The sloping surface
152 is located opposite the aforementioned sloping
surface 100 located on the rear face of the cylinder
component. It will be understood that extension of
the piston component from the cylinder component will
cause interengagement of the sloping sùrfaces,
thereby providing a further mechanism for holdinn the
split ring on the roll neck.
Figure 11 illustrates an alternate construction
for the hydraulic fastener of the invention. Except
as described hereinafter, the construction of this
~- alternative is substantially similar to that
described above. The hydraulic fastener or hydraulic
nut is held in position on the reduced end of the
roll by a split ring 162 similar to that shown in
Figures 9 and 10. However instead of bearing
-~'
directly against the inner bearing support, the
piston of the hydraulic fastener bears against a
solid steel ring 164 that extends about the reduced
end portion 166 of the roll.
.
- ~n 1~1137 ~
The inner face of the rinq 164 axially supports and
positions the inner bearing support 168 which rotates
with the roll. It will be particularly noted that in
this embodiment there are two bearing supports lh~
! 5 required to support four rows of bearin~s 17n. This
configuration is an example of a bearing arranqement
that can be used in place of the plane bearing
arrangement shown in Fi,qure 1.
The embodiment of Fi~ure 11 is equipped with a
mechanical locking device 172 capable of holdinq the
, roller bearin~s in place (and therefore the end of
the roll in place) in event of failure of the
hydraulic fastener 160. The ring 172 has an inwardly
extendin~ flan~e 174 having an inner diameter which
is less than the outer diameter of an outwardly
extending flange 176 formed on the rin~ ],64. After
the bearinqs have been secured in place using the
hydraulic fastener, the flange 174 is hrought into
~, close engagement with the flanqe 17~. It will be
readily seen that in the event that the hydraulic
fastener should fail, outward movement of the ring
164 is still prevented by the ring 172 and its flange
174. Leaka,qe of lubricant from the bearings 17n is
prevented by a suitable seal 178 which i.s secured in
place by a further rinq 18n detachably connected to
the ring 172 by bolts 182.
- 21 - 131137~
The space between the hydraulic nut 16~ and the ring
164 is protected by a lip seal 1~4 of known
construction. This circumferential extending seal is
firmly mounted on the outside of the cylinder of the
5 hydraulic fastener 160.
Figure 12 illustrates another embodiment of the
hydraulic fastener of the present invention, which
fastener is provided with a mechanical lockinq
device. The reduced end 190 of a back-up roll 192,
only a portion of which is shown, has mounted thereon
a hydraulic fastener 194. This hydraulic fastener is
constructed in a similar fashion to the hydraulic
fastener already described and illustrated in Figure
2 of the drawings. The hydraulic fastener is held in
place by a split ring 196 which is connected to the
roll neck 198. Also shown in Figure 12 is the inside
, section 200 of a plane bearing, which section rotates
with the roll 192. It will be understood that this
inside section has a polished surface at 202. A
portion of a retaining collar 204 of known
~ construction is also shown in Figure 12.
; Unlike the hydraulic nut of Figure 2, the
hydraulic nut 194 is threaded on its outer surface at
206. There is provided on this outer surface a
mechanical lockin~ ring 208 that is internally
threaded. Also provided in this version of the
invention is a further mechanical locking ring 210.
1 3 ~ 7
- 22
It is arranged between the hydraulic nut 194 and the
plane bearing 200. In the installation of the
bearing 200, the locking ring 210 is placed in the
position shown in Figure 12 and then the hydraulic
nut 194 is expanded (by injection of grease) so that
it bears firmly against the ring 210. After this
operation has been carried out, the locking ring 208
can then be threaded further towards the right in
Figure 12 so that it also bears firmly against the
locking ring 210 as shown. It will thus be seen that
in the event of failure of the hydraulic nut 194, the
locking ring 210 and the plane bearing 200 will still
bè held firmly in place by the mechanical locking
ring 208.
In the embodiment of Figùre 13 there is a
hydrualic nut 230, only portions of which are shown
for ease o illustration. This hydraulic nut includes
a ring cylinder component 232 and a ring piston
component 234. In this version the piston component
has an axial extension 236 which projects a
substantial distance inwardly from the inner face 238
of the cylinder component. The extension 236 has a
radially outwardly extending flange 240 which forms
means for pulling an adjacent bearing member. This
flange fits under a ring member 242 that is bolted to
the inside section 244 of a plane bearing, which section
rotates with the roll. The ring member 242 has a
radially inwardly extending flange 246 whose interior
diameter is less than the exterior diameter of the
flange 240. It will be readily seen that retraction
, of the piston component 234 into the cylinder
1311~7~
_ 23
component will also cause retraction of the inside
section 244 of the bearing. In this way the
hydraulic nut 230 serves the dual function of not
only holAing the bearing component in place but also
helpin~ to remove the bearing component when this is
required.
The construction o~ the end of the roll in the
embodiment of Figure 13 should also be noted. The
reduced dia~eter end section 250 is provided with a
shoulder at 252 against which part of the inner
surface 238 of the cylinder component rests. Thus
axially inward movement of the cylinder component
beyond the shoulder 252 is prevented.
As in the above described version of the roll,
there is a circumferential recess 254 near the outer
end of the roll. A suitable split ring 25h which
holds the hydraulic nut 230 in place extends into the
recess 254.
There is also shown in Figure 13 part of a
retaining collar 257 of known construction. A seal
(not shown) is arranged between the hydraulic nut 230
and the retaining collar 257 in the gap 258.
Figure 14 is a cross-sectional detail showing
another version of the hydraulic nut of the invention
being used to retain the bearings of a working roll.
For ease of illustration, the hydraulic nut 260 has
only been shown in outline in Fiqure 14 but it will
be appreciated that the nut 2hO is similar in its
construction to the hydraulic nut of Fi~ure 2 except
as explained hereinafter. The nut 260 is held in
- ~4 - 13~1377
place by a suitable split ring 262 that is mounted in
a circumferential recess formed in the roll.
Extending about the radially outer surface of the
hydraulic nut is a hydraulic nut retaining ring 2~4
which is attached by bolts 266 to the side of the
chock 268. The retaining ring 264 has an axially
extending flange 27n that extends inwardly between
the chock 268 and the cylinder component ~72 of the
hydraulic nut. In order to seal the gap between the
hydraulic nut and the retaining ring 2h4 there is a
rotating seal 274 which could be a lip seal or a
filled Teflon* seal. The particular form of this
seal would depend upon the particular application.
In this embodiment the piston component of the
hydraulic nut bears a~ainst a wear rin~ and spacer
276 which in turn bears against the inner roller
bearing support 278. Extending about the
circumference of the spacer 276 is a spring loaded
garter seal 28n of known construction. Located
axially outwardly from the seal 280 is a back-up ring
282 that is also a known component of a working roll
bearing arrangement.
It will be seen that the configuration of
Figure 14 provides an effective seal between the
chock 268 and the hydraulic nut 260 located therein.
This prevents any dirt or other foreign matter from
entering into the gap between the chock and the
hydraulic nut where it might cause dama~e or
unnecessary wear.
'
* trade mark
131~77
- 25
Turning now to Figures 15 and lfi of the
drawings, these drawin~s illustrate an alternative
hydraulic arrangement for a hydraulic nut constructed
in accordance with the invention. In particular,
Figure 15 i]lustrates the passageways provided for
charging and discharging the hydraulic material in
order to expand the hydraulic nut. In particular,
there is provided an axially extending charging
passageway 290 which is provided with a threaded seat
292 to which a hydraulic line can be attached. The
passage 290 has a reduced diameter end section that
intersects a radially extending passageway 294. The
radially outer end of the passageway 294 is sealed by
a steel ball 296 which together with a spring 298
forms a high pressure relief valve. The spring ~98
is seated in a passageway 300 of increased diameter.
The spring is held in the passageway by an end plug
302 that is threaded into the cylinder component of
the nut. This plug has a central passageway or vent
hole at 304.
Intersecting the passageway 290 at right angles
is a smaller, radially extending passageway 306 which
is sealed at its outer end by a pipe plug 308.
Intersecting the passageway 306 at right angles is a
short passageway 310 which opens into a seat 312 of
greater diameter. At the outer end of the seat 312
is a circular recess 314 into which is fitted a
protective shield (not shown) for the hydraulic
connection. It will be understood that the hydraulic
material is fed through the passageway 290 and the
1311377
- 26
smaller passageway 294 in order to expand the nut.
The hydraulic material can be discharged or removed
through the passageway 306 and the connecting passage
3ln.
Figure 16 illustrate an alternate arrangement
for the hydraulics to retract the hydraulic nut. In
this embodiment there is a main axially extending
passa~eway 320 which has an inner portion 822 of
reduced cross-section. At the outer end of the
passageway 320 is a threaded seat 324 and ~llen key
slot. The portion 322 is intersected at an oblique
angle by a short passageway 326 which opens into the
space 120 defined in part by the piston component and
the retainin~ rin~ 58. It will be understood that in
order to retract the nut, the user pumps the
hydraulic material through a suitable hydraulic hose
(not shown) that is connected up to the outer end of
the passageway 320. The hydraulic material flows
through the passageway 320 and through the passageway
326 into the space 12n. Excessive pressure build up
is prevented by the use of a built-in pressure relief
valve that includes a steel ball 32~ that is acted on
by a coil spring 330. The ball 328 rests a~ainst the
outer end of a short ~assageway 332 which intersects
the passageway 322. The spring is held in its
passageway 334 by a suitable plug 33h that is
threaded into the cylinder component. The 33fi has a
vent hole to permit the outward passage of gréase
when this valve opens. The pressure at which the
valve releases is adjustable in a known manner by
means of the plug 336.
13~1~77
- 27
For the discharge of grease from the space 12n,
there is provided a radially extending ~assa~eway 340
which intersects the wide section of the passageway
320. Another shorter passaqeway 342 intersects the
passageway 340 at right anqles and opens into a
threaded seat 344 to which a hydraulic line can be
connected. The outer end of the passa~eway 3~0 is
: ~locked by a pipe plug ~46. Thus, it will be
understood that when the hydraulic nut is being
expanded, the grease can be forced out of the space
120 and out through passageways 340 and 342 into a
hydraulic line.
If desired, one can provide means for
preventinq relative rotation of certain major
components with respect to their adjacent components.
For example, one can provide a notch on the front
face of the hydraulic piston component 56 and a
cooperating keyway on the opposing face of the
adjacent bearing member to prevent relative rotation.
As such means for preventin~ relative rotation are
well known, these optional features have not been
illustrated in the drawings. Similarly, one could
provide cooperating notches and keyways between the
piston component 56 and the ring cylinder component
52 and between the cylinder component 52 and the end
of the roll on which it is mounted.
1311377
- 2~ -
It will be clear to those skilled in this art
that various modifications and chan~es can be made to
the illustrated versions of the invention without
departin~ from the spirit and scope of this
invention. For example, instead of usin~ standard
bolts to hold the split rin~ formed by the two halves
142 in place, one could use a lar~e rubber ~-rin~
that extends about the circumference of the two
halves and rests in a suitable groove form~d in the
outer surface of the split rin~. Also instead of two
bolts on one side of the split rin~, one could employ
a suitable hinge that pivotally connects the two
halves to~ether. Also one could replace the s~lit
rin~ with the use of thread on the inside of the
cylinder com~onent 5~ and on the reduced diameter
æhaft of the roll. In this embodiment the cylinder
component wo~lld be threaded onto the roll end and
thereby held securely in place. All such
modifications and chan~es that fall within the scope
of the appended claims are intended to be part of
this invention.
