Note: Descriptions are shown in the official language in which they were submitted.
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DEFLECTION AW USTABLE ROLL
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the priority of German
Application No. DE 44 30 666.0, filed August 29, 1994, the
disclosure of which is incorporated herein by reference in its
entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to a deflection adjustable
controlled roll comprised of a fixed carrier and a roll jacket
rotatable about the carrier, with the roll jacket being
supported on the carrier via several support elements, wherein
each support element has at least one cylinder-piston device,
for the formation of a contact force, and a bearing shoe with
a separate lubricating fluid supply and wherein the fluid
supply of pressure chambers of the cylinder-piston devices is
accomplished at least in separated groups, with such rolls
being utilized during the production or treatment of web
shaped materials.
0 2. Discussion of the Background of the Invention and Material
Information
Such rolls are known, for example, from Swiss Patent
Publication CH-PS 673 051. Added to this is that in this
solution the delivery of the pressure fluid, to the pressure
chamber of the cylinder-piston devices, is separated from the
supply of the lubricating fluid to the bearing pockets of the
bearing shoes. In addition to the thermal separation of the
fluid circuits, this solution has the particular advantages
that the lubrication is carried out independently of the
pressure circuit and thereby not, as is the case with a
connection between the pressure chambers and the bearing
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pockets, there is a proportional dependence of the quantity of
the lubrication fluid upon the pressure in the cylinder-piston
device. The remaining disadvantage is that, in operation, the
possibly occurring vibrations, cannot be damped to a
sufficient degree.
In addition, rolls having a large number of support
elements also require a large number of pressure conduits,
whose diameter, due to the limitations of the roll or of the
carrier, must thus be quite small. This in turn has a higher
sensitivity with respect to leakage. While it is known that
the thus resulting pressure losses can be compensated via a
pressure reservoir located outside of the roll, such a
solution will fail in most instances due to the high costs
thereof.
It is thus the task or object of this invention to
produce a deflection adjustable roll whose pressure supply is
provided in a pressure reservoir manner, at low cost and
which, particularly even in the support of a high number of
support elements, acts in a vibration damping manner, at low
cost.
SUMMARY OF THE INVENTION
This task or object is achieved via the devices set forth
in the appended claims wherein a main embodiment of the
deflection adjustable roll of this invention is comprised of
a fixed carrier and a roll jacket rotatable about the carrier,
with the roll jacket being supported on the carrier via
several support elements, wherein each support element has at
least one cylinder-piston device, for the formation of a
contact force, a bearing shoe with a separate lubricating
fluid supply, wherein the fluid supply of pressure chambers of
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the cylinder-piston devices is accomplished at least in
separated groups, wherein at least one of each respective
pressure chamber without a consequence upon the distance
between the roll jacket and the carrier and at least one
section of the pressure conduit, which connects each pressure
chamber with a pressure source, changes the pressure fluid
chamber storage capacity thereof, versus a force, in
dependence upon the pressure emanating from the pressure fluid
itself.
In that manner, since each pressure chamber, without
influencing the distance between the roll covering and the
carrier and/or of at least one section of the pressure conduit
that connects the pressure chamber with a pressure source, up
to a predetermined degree, changes the chamber capacity of the
pressure fluid versus a force in dependence upon the pressure
emanating from the pressure fluid itself, that is, which
particularly increases its holding capacity during the
increasing pressure of the pressure fluid, vibrations
emanating from the roll covering can be damped at low expense
and the pressure of the pressure fluid, even during leakage
thereof, can be maintained to a substantial degree. The
chamber capacity increase is above that of pressure conduits
made of metal.
With regard to the other embodiments of this invention,
it is herewith also possible that a least a section or segment
of the pressure conduit is comprised of flexible material
and/or that at least one wall, forming a boundary of the
cylinder-piston device, is formed as a sealingly guided piston
wherein the piston is supported on a spring member that acts
in the direction of the pressure chamber. This spring member
can, for example, in the form of a cup or plate spring, act in
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a vibration-damping manner and/or be provided in parallel with
or with series engaged damping elements.
In order that the support elements, particularly in
regard to vibration damping, behave in the same manner, the
pressure conduits, provided between the pressure source and
each respective pressure element, should be substantially
identical in terms of construction and material composition,
and above all, should be of substantially the same length.
Since the support elements are located at different distances
from the roll ends, it is recommended in this connection that
at least the section of the pressure conduit, that extends
within the deflection adjustable roll, be comprised of
elastic, flexible, vibration damping material, wherein the
portions of the pressure conduits that are located within the
deflection adjustable roll already have the same length, that
is, that the differing distances that the support elements can
be compensated for via a corresponding rerouting or relocation
of the at least partially flexible pressure conduits.
The use of pressure conduits, in addition, in contrast to
the normally usually axially extending bores in the carrier,
in regard to the expense involved, represents a sensible from
of implementation, if a large number, for example, more than
thirty support elements are to be independently controlled.
The lubrication of the gap between the bearing shoe and
the roll covering can be accomplished either hydrodynamically
and/or hydrostatically. During at least partial hydrostatic
operation, the bearing shoes of the support elements within
the utilized or effective bearing area, have hydrostatic
bearing pockets, which as already previously noted are
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preferably separately supplied with a lubricating fluid by the
pressure conduits of the pressure chambers.
An advantageous embodiment thereby results if a portion
of the bearing shoe, which forms the bearing surface, at the
same time forms a portion of an axially extending ledge or
strip that extends over several support elements. This is,
among other things, favorable in terms of the construction
costs, when the strip includes at least one axially extending
bore for the supply of the lubricating fluid to the bearing
pockets. If several axially arranged strips are utilized, the
axial bores thereof should be connected directly with each
other, without however significantly limiting the relative
flexibility of the adjacent strips.
In order that the strip adapts or conforms itself to the
roll covering, the strip should be more flexible than or at
least be similarly as flexible as the roll covering. In
addition, it is of advantage if the strip includes several
channels extending in approximately the circumferential
direction of the deflection adjustable roll. This provides
the possibility for reducing the turbulence or vorticity
losses emanating from the fluid that collects between the roll
covering and the carrier, since this fluid, during rotation,
can flow through the channels.
Since at least portions of the deflection adjustable roll
heat up during operation, and the strip has a differing, for
example, lesser coefficient of thermal expansion than the
carrier, it is of advantage if the strip is relatively rigidly
connected with the support element, so that the support
elements are pivotally supported on the carrier in at least
the axial direction, so that the support elements, starting at
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a slight inclination to the nearest respective end of the
deflection adjustable roll, in a non-temperature controlled
state, at the operating temperature, can incline slightly
toward the middle of the deflection adjustable roll.
Due to the low leakage and the limitation of the stress
or tension of the pressure chamber and/or of the pressure
conduits, it is possible, without difficulty, at times, to
separate the pressure chambers from the central pressure
source, as long as the pressure is maintained. Even during
leakage of pressure fluid from the cylinder-piston device, the
pressure of the pressure fluid will only change slightly.
Particularly in the control of a large number of support
elements, an economical variation provides, that the pressure
conduits are connected only singly and subsequently with the
pressure source that determines the corresponding pressure.
In order to minimize the required cycle time, it is of course
also feasible that groups of support elements are each
associated with a pressure source.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention which is set forth with reference to three
main embodiments thereof will be better understood and objects
other than those set forth above will become apparent when
consideration is given to the following detailed description
thereof. Such description makes reference to the annexed
drawings wherein throughout the various figures of the
drawings, there have generally been used the same reference
characters to denote the same or analogous components and
wherein:
Fig. 1 is a partial cross sectional view of the
deflection adjustable roll of this invention;
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Fig. 2 is a substantially schematic representations of a
second main embodiment of this invention; and
Fig. 3 is a substantially schematic representations of a
third main embodiment of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS AND BEST
MODE
With respect to the drawings it is to be understood that
only enough of the construction of the invention and the
surrounding environment in which the invention is employed
have been depicted therein, in order to simplify the
illustrations, as needed for those skilled in the art to
readily understand the underlying principles and concepts of
the invention.
The deflection adjustable rolls of this invention are
essentially comprised of a carrier 1 and a roll covering or
jacket 2 rotatable thereabout, with covering 2 being supported
via several axially extending support elements 3 on carrier 1.
Such deflection controlled rolls preferably form, with other
rolls, an apparatus or gap for the production or treatment of
web shaped material, for example fiber webs or bands.
In order to act upon even locally limited irregularities
of the fiber web, the implementation of multiple axially
arranged, relative to the roll, pressure zones is important.
In order that support elements 3, having a width of, for
example, 40 - 100 mm, show only a locally limited effect, in
these cases the flexible roll coverings 2 are of major
importance.
Each of support elements 3 includes a cylinder-piston
device 4, for the formation of a contact force, and a bearing
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shoe 5. As per Fig. 1, pressure chambers 6, without a
substantial change of the distance between roll jacket 2 and
carrier 1, together with a predominant section 7 of pressure
conduit 8, which connects each pressure chamber 6 with the
pressure source, change their pressure fluid retention volume
to a certain degree, versus or against a force, in dependence
upon the pressure emanating from the pressure fluid itself.
This is accomplished in tangible form, in one instance,
in that a wall, forming the boundary or limit of cylinder-
piston device 4, in this instance it being the piston orannular piston 9 itself, which is sealingly guided or
supported at the cylinder as well as a pin 15 that also
contains the fluid inlet, is supported on a spring member 10,
here in the form of a packet of cup or plate springs, acting
in the direction of pressure chamber 6. In another instance,
the pressure conduits are provided in an identical manner,
wherein a predetermined section or segment 7 of pressure
conduit 8, that is located within the deflection adjustable
roll, are comprised of elastic , flexible , vibration-damping
material and wherein the portions of pressure conduits 8,
located within the deflection adjustable roll, are of
substantially equal length. This ensures that all support
elements act in the same manner, since the damping and
pressure accumulation emanates substantially from spring
member 10 and the elastic material of pressure conduits 8.
The lubrication of the bearing shoes 5 is accomplished
here in a hydrostatic manner, via hydrostatic bearing pockets
11 arranged within the actual or effective bearing surface,
with the bearing pockets being supplied, separately by
pressure conduits 8 of pressure chambers 6, with a lubricating
fluid, so that the lubrication as well as the temperature
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control of the aperture or gap can be accomplished
independently.
In order to even out the transitions between the support
elements 3, particularly with the use of flexible roll
coverings 2, the portion of the bearing shoe 5 that forms the
bearing area is, at the same time, a portion of an axially
extending ledge or strip 12, in order to simplify the input of
the lubricating medium to bearing pockets 11, includes an
axially extending bore 13, which is connected, at the ends
thereof, with a conduit extending from the deflection
adjustable roll and includes, of course, throttling channels
to bearing pockets 11.
In order that strip 12 can even out the regions or areas
between support elements 3, strip 12 is of flexible
construction. In addition, strip 12 also includes several
additional channels 14 that extend in approximately the
circumferential direction of the deflection adjustable roll,
with these channels permitting a through flow of the fluid
that accumulates in roll jacket 2, thereby reducing the
turbulence or vorticity losses.
If, for example, carrier 1 is made of metal and strip 12
is made of plastic material, due to the differences in the
coefficients of thermal expansion, support elements 3 are
pivotally or swivellably arranged at carrier 1 in the axal
direction. The connection of pin 15 with pressure conduit 8
must be constructed correspondingly. In this manner, it
becomes possible that support elements 3, starting at a slight
inclination to the nearest respective end of the deflection
adjustable roll in an non-temperature controlled state, at
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higher operating temperatures, can incline slightly toward the
center or middle of the deflection adjustable roll.
Due to the energy storing or accumulating construction of
pressure chamber 6 and of sections 7 of pressure conduits 8,
it is possible, at times, to separate pressure chamber 6 and
its pressure conduits 8, from the pressure source that is
located outside of the deflection adjustable roll. A
connection with the pressure source could be affected
cyclically or only when the pressure, in a pressure chamber,
is changed, insofar as a definite time period, for example in
the range of minutes, is not exceeded. This serves to reduce
the control expenses, particularly with deflection adjustable
rolls having a large number of support elements 3.
In order to simplify the assembly it is of advantage that
all pressure conduits 8 are joined with from the roll via an
easily detachable multiple coupling. This can be
accomplished, for example, via two opposed, sealed and
detachably connected apertured plates, whose apertures or
holes overlap each other and are each connected with a joint
or terminal of a pressure conduit 8.
In order to improve the damping characteristics, it is of
course possible to provide pressure conduits 8 with additional
damping elements.
Figs. 2 and 3 illustrate two other embodiments in order
to permit that pressure chambers 6 of cylinder-piston devices
4, with a substantial change of distance between the roll
jacket 2 and carrier 1, can change their chamber or volume
capacity for the pressure fluid against or versus a force, in
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dependence upon the pressure emanating from the pressure fluid
itself.
This task is achieved as per Fig. 2 in that a preferably
damping spring member 10 is arranged between bearing shoe 5
and cylinder-piston device 4.
It is however, as per Fig. 3, also possible to support
cylinder-piston device 4 itself on carrier 1, via a highly
damped member 10.
In both instances, additional damping elements, as
already described, can be utilized. In some circumstances,
the embodiments can also be combined with each other.
While there are shown and described present preferred
embodiments of the invention, it is to be distinctly
understood that the invention is not limited thereto, but may
be otherwise variously embodied and practiced within the scope
of the following claims and the reasonably equivalent
structures thereto. Further, the invention illustratively
disclosed herein may be practiced in the absence of any
element which is not specifically disclosed herein.
