Rotating body of a web-fed press
A rotating body of a web-fed press, in which one or more hot spots develop in at least one sector of at least one of two or more rotating bodies due to the rolling of the two or more rotating bodies on one another. The rotating body has at least one inhomogeneity in the form of a material recess, so that heat conduction or thermal expansion is interrupted at the site of the material recess.
1 . A rotating body which rolls against another rotating body in a web-fed press, said rotating body comprising:
a circumferential surface concentric to an axis of rotation;
a pair of opposed end faces; and
at least one material recess which interrupts conduction of heat so that non-uniform linear expansion is at least reduced.
2 . The rotating body of claim 1 wherein said material recess comprises a groove which extends at least partially around the circumference of the rotating body.
3 . The rotating body of claim 2 wherein the groove is formed as a helix around the circumferential surface.
4 . The rotating body of claim 2 wherein the groove has a width of 0.1 mm to 50 mm.
5 . The rotating body of claim 1 wherein said at least one recess comprises at least one bore in the circumferential surface.
6 . The rotating body of claim 5 wherein the bore has a depth of 1 mm up to the diameter of the rotating body.
7 . The rotating body of claim 1 wherein the bore extends parallel to the axis.
8 . The rotating body of claim 1 wherein said at least one material recess comprises a plurality of ring grooves extending around the circumferential surface, said rotating body comprising a plurality of coaxially arranged disks, at least some of said disks having a circumferential portion forming a base of a respective said groove.
9 . The rotating body of claim 8 wherein said disks comprise first disks having a first diameter and second disks having a second diameter which is smaller than said first diameter, said second disks consisting of a different material than said first disks.
10 . The rotating body of claim 1 further comprising a thermally insulating material filling said at least one material recess.
11 . The rotating body of claim 10 wherein said thermally insulating material is in a solid state at 20° C. and has a thermal conductivity of 0.05 (W/(K×m)) to 40 (W/(K×m)).
12 . The rotating body of claim 10 wherein said thermally insulating material is in a liquid state at 20° C. and has a thermal conductivity of 0.1 (W/(K×m)) to 10 (W/(K×m)).
13 . The rotating body of claim 10 wherein said thermally insulating material is in a gaseous state at 20° C. and has a thermal conductivity of 0.01 (W/(K×m)) to 0.3 (W/(K×m)).
14 . The rotating body of claim 1 wherein said material recess comprises a groove in at least one of said end faces of said rotating body.