DE102007018479A1 - Roller for e.g. paper machine, has roll base connected to inner surface of roll body, where heat expansion of roll base in radial direction in specific temperature ranges is equal to or larger than radial heat expansion of roll body - Google Patents

Abstract

The roller (1) has a cylindrical roll body (3) pivoted around a pivot axis by two bearing pins (5) that are held at a roll base (4). The base extending in a radial direction of the body is connected to an inner surface (6) of the body, where heat expansion of the base in the radial direction in a temperature range of 20-250 degrees is equal to or larger than radial heat expansion of the body. The base formed from fiber-reinforced plastic e.g. carbon fiber-reinforced plastic, has inner and outer ring sections, where the outer section extends from the inner section to the body surface.

Description

The The invention relates to a roller for a web-processing machine, in particular paper, cardboard or Tissue machine, according to the preamble of patent claim 1.

at Rollers which are mounted on pins, usually the roller body is on both ends each completed by a roll bottom. Each roll bottom holds in each case one of the journals. Since the two bearing journals the axis of rotation of To specify a roller the journals and thus the two roll trays firmly connected to the roll body be.

in the In the prior art, roll bases are used, the complete made of metal, such as steel. Especially in journal-mounted rollers with a roll body made of a fiber composite material The problem may occur because of the different thermal expansion steel and the composite at certain temperatures, which can occur during operation of a web-processing machine, to a Loosening of the connection between the roll bases and the roll body comes. For example, a steel roll base in the radial direction expands less than a roll body made of a fiber composite material with in the longitudinal direction of roller body oriented fibers expands in its radial direction.

It the object of the present invention is a roller of the input mentioned type with a throughout the temperature range during operation of the Roller improved connection between the roller floors and to propose the roll shell.

The The object is achieved by a roller for a web-processing machine, in particular paper, cardboard or Tissue machine, with a cylindrical roller body, wherein the roller body by means of two held on a roll bottom bearing pin around a Rotary axis is rotatably mounted and in which each roll bottom in the radial direction of the roller body extends and on the inner surface the roll body attached to this is connected. According to the invention is at least in a temperature range of 20 ° C up to 250 ° C the thermal expansion the roll bottom in the radial direction of the roll body the same or greater than the radial thermal expansion the roll body.

The Invention is based on the idea that the connection between the rolling floors and the roll body only upright under all temperature conditions occurring during operation can be obtained when the two components, d. H. Walzenboden and roll body, in the radial direction of the roller body either expand thermally equally or the roll bottom in the radial direction of the roller body more than the roll twill in its radial direction. Since the roll bottom in its radial extension is supported on the inner surface of the roller body arises thus at a temperature increase no tension in the connection between the roll bottoms and the roll body, which weakens the connection but rather no tension or compressive stress, the last mentioned the radial connection between roll body and Rolled bottom rather reinforced.

advantageous Embodiments and developments of the invention are specified in the subclaims.

A preferred embodiment of the invention provides that the roll bottom with the roller body force fit and / or cohesive connected is. Frictional or cohesive Connections represent particularly inexpensive connection types but have the disadvantage that they act at right angles to the contact surface tensile forces weakened become. Since it is ensured by the invention that also in thermal influence no perpendicular to the contact surface acting tensile forces in the radial direction of the roller body between the roll base and the roll body it is only possible for use in the above-mentioned temperature range in a web-processing Machine to realize a positive or cohesive connection.

Under a non-positive Connection is a connection to be understood by the application of force, which is generated by suitable bias. These include z. B. compressive forces or friction forces. Exemplary for a non-positive Connection is a press fit to call.

Under a cohesive Connection is a connection to understand in which the connection partners held together by atomic or molecular forces become. A cohesive connection is at the same time a non-releasable one Compound, which can only be destroyed by the means of connection can be separated. Exemplary for a cohesive Connection is an adhesive bond to call.

An embodiment of the invention provides that the thermal expansion of the roll base in the radial direction of the roll body is at most 20%, in particular at most 10%, greater than the radial thermal expansion of the roll body. As a result, too strong compressive stresses on the Prevented roll body and its deformation.

to Determination of thermal expansion becomes proceed as follows: It is assumed that a roll base or roll body, and the diameter measured at a lower temperature (e.g. Room temperature). Furthermore, this measurement becomes at a higher temperature, in the range up to 250 ° C lies, z. 100 ° C, repeated. The thermal expansion then calculated from the diameter difference in the two Temperatures divided by the diameter at the lower Temperature and divided by the temperature difference.

Preferably is the roll base at least in sections made of a fiber composite material, in particular fiber-reinforced Plastic, built. Furthermore, it is conceivable that the roll base considered in its radial extent an inner ring portion and an outer ring portion includes. Here, the inner ring section serves as a receptacle or a Mount for the journal and the outer ring portion extends from the inner ring portion to the inner surface of the Roll body. To the appropriate thermal expansion the roll base optimally according to the specific by the thermal expansion the roll body to be able to set predetermined requirements, sees a preferred Embodiment of the invention, that at least the outer ring portion the roll base comprises a fiber composite material.

Of Another is provided according to a development of the invention, that the outer ring section has an at least partially hollow or foamed core, at least is partially enclosed by the fiber composite material. These Design also has manufacturing advantages, since the hollow or foamed Core, which is also usually ring-shaped, in the production the roll bottom is fitted onto the inner ring and as a winding shape during winding of the fiber composite during the formation of the outer ring serves. As a result, at least the outer ring portion of the roll tray becomes produced by a filament winding process. This is it is possible the thermal expansion coefficient of the outer ring portion through the winding angles of the various fiber layers that used Fiber material and the plastic matrix material to set so targeted, the roll base in the radial direction of the roll body an equal or greater thermal expansion as or as the roll body in its radial direction, in particular that, for example, the outer ring portion in the radial direction of the roller body a thermal expansion coefficient that's equal to or greater than that CTE the roll body in its radial extent. At the concrete vote the thermal expansion coefficient of roll body and roll bottom makes you, for example, the knowledge to use that Fibers whose thermal expansion in the fiber direction is less than the thermal expansion of the resin matrix, z. As C-fibers, aramid fibers, the thermal expansion in the radial direction the smaller, the closer the winding angle in the circumferential direction.

For example. can the thermal expansion according to the invention between roller body and roll base can be achieved by adding a proportion of fibers the roll bottom in approximate Circumferential direction, z. As a proportion of fibers from 10% to 50% orientation from 60 ° to 90 ° to the longitudinal axis the roll has, in particular the proportion of fibers and / or the orientation angle of the fibers is smaller than that in the roll body.

Becomes a hollow body, eg hollow plastic body, used as a core, this has the further advantage that this when joining the roll base with the inner surface of the roll body in his Inside can be pressurized, which is due to the expansion the hollow core of the outer ring section at the contact surface against the inner surface the roll body is pressed and thus the positive and / or cohesive connection between Roll bottom and inner surface the roll body supports becomes. The pressurization of the interior of the expansible hollow body has but only as long as a pressing of the outer ring section against the inner surface the roll mantle to follow, as long as the outer ring portion forming Fiber composite material is not completely cured.

When suitable combination of materials for the fiber composite material of the roll body proves to be particular as advantageous if the fiber-reinforced plastic as a fiber material Alone or in combination carbon fibers, glass fibers or aramid fibers and as the plastic material comprises epoxy resin.

Of Furthermore, an embodiment of the invention provides that the inner Ring section made of a metallic material or of a fiber composite material is made.

When constructing rolls for use in a web-processing machine, the roll body is increasingly made of a fiber composite material, in particular fiber-reinforced plastic, due to the variably adjustable properties depending on the chosen design and the low weight. To provide a roll with high rigidity, in particular bending stiffness, in its longitudinal direction, it is particularly useful if the fibers of the fiber composite material of Walzenkör pers are oriented substantially in the longitudinal direction of the roller body. The fiber-reinforced plastic used is preferably CFRP (carbon fiber reinforced plastic).

Concrete can the structure of the roller body through Combination of fiber layers with different winding angles done. In this case, for example, layers with about 0 ° to 30 ° winding angle with respect to the axis of rotation the roller with layers of about 60 ° to 90 ° winding angle combined in relation to the axis of rotation of the roller. In between can be layers be attached by angles between the upper orientations.

One concrete example is: Alternating layers of approx. + -8 ° and approx. + -75 ° where the Proportion of 75 ° layers about 30%.

The The invention will be described below with reference to a schematic not to scale Drawing closer explained.

The sole figure shows a roll according to the invention 1 in a sectional plane along the axis of rotation 2 the roller 1 in sections in the area of one of its longitudinal roll ends.

The roller 1 has a cylindrical roller body 3 , on each of the two ends a roll base 4 is arranged, wherein in the illustration of the figure only a roll bottom 4 can be seen. At each roll bottom is a journal 5 non-positively and / or cohesively, ie, for example, attached by means of press fit and / or gluing. The two trunnions 5 store the roller 1 rotatable and set their axis of rotation 2 firmly.

The following explanation applies to each of the two long ends with roll bottom 4 to.

The roll bottom 4 extends in the radial direction R of the roller body 3 perpendicular to its axis of rotation 2 , The roll bottom 4 extends to the inner surface 6 the roll body 3 so that the radial end surface 7 of the roll base 4 on the inner surface 6 the roll body 3 is present and with this a contact surface 11 is connected. In the present case, the roll bottom 4 with the roller body 3 frictionally by a press fit and additionally cohesively by a bond at the between the radial end surface 7 of the roll base 4 and the inner surface 6 the roll body 3 connected contact surface connected.

According to the invention, at least in a temperature range of 20 ° C to 250 ° C, the thermal expansion of the roll base 4 in the radial direction R of the roller body 3 equal to or greater than the radial thermal expansion of the roll body 3 , In the present embodiment, the thermal expansion of the roll base 4 in the radial direction R of the roller body 3 maximum 5% greater than the radial thermal expansion of the roll body 3 is.

The roll bottom 4 includes in its radial extent R viewed an inner ring portion 8th and an outer ring portion 9 , wherein the bearing pin 5 on the inner ring section 8th is attached and the outer ring section 9 from the inner ring section 8th to the inner surface 6 the roll body 3 extends.

In the present case, the outer ring section comprises 9 of the roll base 4 a fiber composite part 11 , Specifically, this means that the outer ring section 9 a foamed core 10 has, in the radial direction R concentrically over the inner ring portion 8th pushed. The core 10 is from the fiber composite part 11 enclosed, wherein the core in the production of the fiber composite part 11 has served as a wrapper. The fiber composite part 11 is made of fiber-reinforced plastic with carbon fibers as a fiber material and with epoxy resin as a plastic material, wherein the coefficient of thermal expansion of the outer ring portion 9 is adjusted by the winding angle of the various fiber layers, the fiber material and the matrix material so that the outer ring portion 9 in its radial extent R has a thermal expansion coefficient equal to or greater than the coefficient of thermal expansion of the roll body 3 in the radial extent R is.

So has the roll body 3 For example, a radial thermal expansion coefficient of 15 · 10e - 6 m / m / ° C and the outer ring section 9 a thermal expansion coefficient of> 15 · 10e - 6 m / m / ° C. This can be z. B. can be achieved by the following layer structure:
In each case equal parts are fiber winding layers + -10 °, + -20 °; + 45 °, + -20 ° and + -10 ° applied, wherein the angles on the cylindrical part relative to the axis of rotation 2 and measured at the frontal part relative to the radius.

In the present case is the inner ring section 8th made of a metallic material, such as aluminum or steel. It can also be seen that the journal 5 in sections in the longitudinal direction L of the roller body 3 in the inner ring section 8th is introduced.

Furthermore, the roll body 3 constructed of a fiber composite material, in particular of fiber-reinforced plastic. In the present case, the fiber-reinforced plastic CFRP (carbon fiber reinforced plastic), wherein the fibers of the fiber composite material are oriented substantially in the longitudinal direction L of the roller body and the longitudinal direction L parallel to the axis of rotation 2 runs.

Claims (14)

Roller for a web-processing machine, in particular a paper, board or tissue machine, with a cylindrical roller body, which is rotatably mounted about a rotation axis by means of two bearing journals held on a roller base, each roller base extending in the radial direction of the roller body and on the inner surface of the roller body is connected to this, characterized in that at least in a temperature range of 20 ° C to 250 ° C, the thermal expansion of the roller base in the radial direction of the roller body is equal to or greater than the radial thermal expansion of the roller body. Roller according to claim 1, characterized in that the roll base with the roll body force fit and / or cohesive connected is. Roller according to claim 1 or 2, characterized that the thermal expansion of the roll bottom in the radial direction of the roll body maximum 20%, in particular not more than 10%, greater than the radial thermal expansion the roll body is. Roller according to one of the preceding claims, characterized characterized in that each roll bottom at least in sections from a fiber composite material, in particular fiber-reinforced plastic, is constructed. Roller according to one of the preceding claims, characterized characterized in that each roll bottom in its radial extent considers an inner ring portion and an outer ring portion comprises, the bearing pin is attached to the inner ring portion and the outer ring section extends from the inner ring portion to the inner surface of the roll body. Roller according to claim 5, characterized in that at least the outer ring portion of the Roll base comprises a fiber composite material. Roller according to Claim 5 or 6, characterized that the outer ring section has an at least partially hollow or foamed core, at least is partially enclosed by the fiber composite material. Roller according to one of Claims 5 to 7, characterized that the inner ring portion of a metallic material or is made of a Faserverbundverkstoff. Roller according to one of claims 5 to 8, characterized that the outer ring section in its radial extent, a thermal expansion coefficient that's equal to or greater than that CTE the roll body in its radial extent. Roller according to one of claims 6 to 9, characterized that at least the outer ring portion of the roll base produced by a filament winding process is and the thermal expansion coefficient of the outer ring section the winding angles of the various fiber layers, the fiber material and the matrix material is determined. Roller according to one of claims 6 to 10, characterized that the fiber reinforced plastic the roll base as fiber material alone or in combination with carbon fibers, Glass fibers or aramid fibers and as a plastic material epoxy resin includes. Roller according to one of the preceding claims, characterized characterized in that the roller body a fiber composite material, in particular fiber-reinforced plastic, includes. Roller according to claim 12, characterized in that that the fibers of the fiber composite material of the roll body in essentially in the longitudinal direction the roll body are oriented. Roller according to claim 12 or 13, characterized that the fiber reinforced Plastic of the roll body CFRP (carbon fiber reinforced Plastic) is.