Drying roller and a method for manufacturing the same

Abstract

A drying roller includes at least a cylindrical cylinder shell, two caps which are attached to both sides of the cylinder shell, and two journals which are indirectly fastened to the caps by way of a hollow shaft which is connected to the caps or are directly fastened to the caps, wherein the cylinder shell and the caps are welded to one another by way of an annular weld seam. The weld seam has a joint having at least two mutually opposite and parallel flange regions which are mutually spaced apart. A method for manufacturing a drying roller is also described.

Claims

1. A method for manufacturing a drying roller, the method comprising the following steps: providing a cylindrical cylinder shell having two sides; attaching a respective cap to each of the sides of the cylinder shell; fastening a respective journal to each of the caps; and then welding the cylinder shell and the caps to one another by using an annular weld seam having a joint with at least two mutually opposite and parallel flange regions being mutually spaced apart, said parallel flange regions extending to said interior of said cylindrical cylinder shell, said parallel flange regions forming a minority portion of said joint.

2. The manufacturing method according to claim 1, which further comprises interconnecting each of the journals and a respective one of the caps by using a hollow shaft.

3. The manufacturing method according to claim 1, which further comprises initially tacking each of the caps and the cylinder shell to be welded together to one another by tack welding and only thereafter welding the caps and the cylinder shell to one another by weld beads.

4. The manufacturing method according to claim 1, wherein the at least one spacer is at least one annular spacer.

5. A method for manufacturing a drying roller, the method comprising the following steps: providing a cylindrical cylinder shell having two sides; attaching a respective cap to each of the sides of the cylinder shell; fastening a respective journal to each of the caps; welding the cylinder shell and the caps to one another by an annular weld seam having a joint with at least two mutually opposite and parallel flange regions being mutually spaced apart, said parallel flange regions extending to said interior of said cylindrical cylinder shell, said parallel flange regions forming a minority portion of said joint; and after the caps have been welded to the cylinder shell, checking the weld seam from inside through an inspection opening.

6. The manufacturing method according to claim 5, which further comprises interconnecting each of the journals and a respective one of the caps by using a hollow shaft.

7. The manufacturing method according to claim 5, wherein the caps and the cylinder shell on both sides of the weld seam have cylindrical radially inward workpiece faces.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) Further advantages, objectives, and properties of the present invention will be explained by means of the following description of exemplary embodiments which are also illustrated in particular in the appended drawing, in which:

(2) FIG. 1 schematically shows an exemplification of a drying roller;

(3) FIG. 2 shows a part-region of the exemplification of FIG. 1;

(4) FIG. 3 shows an exemplified part-region of a drying roller having a transitional groove, in an illustration which is similar to FIG. 2; and

(5) FIG. 4 shows an exemplified part-region of a drying roller having a step-like transitional groove, in an illustration which is similar to FIGS. 2 and 3.

DESCRIPTION OF THE INVENTION

(6) A substantially cylindrical drying roller 1 which is exemplified in FIG. 1 comprises a cylinder shell 2 and two caps 3 which are attached to both sides of the cylinder shell 2 and which by means of an annular weld seam (not visible in FIG. 1) are welded to the cylinder shell 2. In an interior space 4 which is enclosed by the cylinder shell 2 and the caps 3, the drying roller 1 furthermore has a hollow shaft 5 which extends between the caps 3 and is provided with through openings. In each case one journal 6 is provided on an outer face of each of the caps 3. The cylinder shell 2, the caps 3, the hollow shaft 5, and the journals 6 here are disposed coaxially along a longitudinal axis 7, such that an overall axially symmetrical construction of the drying roller 1 results. The drying roller 1, by means of the journals 6, may be mounted in suitable bearings (not illustrated in FIG. 1) so as to be rotatable about the longitudinal axis 7. The hole provided for the hollow shaft 5 may also serve as an inspection opening 20 for inspecting the annular weld seam 8 (which is not visible in FIG. 1, but is shown in FIG. 2) Alternatively, an additionally provided hole can serve as an inspection opening.

(7) During operation of the drying roller 1 the outer face of the cylinder shell 2 is at least partially wrapped by paper to be dried, or paper to be dried is overlaid onto the outer face of the cylinder shell 2, respectively. Pressure rollers (not shown in FIG. 1) here press the overlaid paper against the cylinder shell 2. Hot steam, having a pressure of usually 3 to 8 bar and which may be up to 12 bar or more, is directed via the hollow shaft 5 into the interior space 4. A drying operation of the paper overlaid on the cylinder shell 2 by means of a heat exchange between the surface of the cylinder shell 2, which as a result of the hot steam in the interior space 4 is hot, and the paper now takes place.

(8) A part-region of the drying roller 1, which in FIG. 1 is identified with A, is illustrated in an enlarged manner and in cross section in FIG. 2, wherein part of one of the caps 3 and part of the cylinder shell 2, and between those the weld seam 8 which has already been mentioned above, can be seen. It may be derived from FIG. 2 in particular that mutually facing faces of both the cap 3 as well as of the cylinder shell 2, which belong to the joint of the weld seam, have in each case first flange regions 9 which are sloped toward one another, and second flange regions 10 which are parallel with one another and are mutually spaced apart. A substantially V-shaped cross section of the weld seam 8, which widens toward the outer side of the cylinder shell 2 and tapers off toward the interior space 4, thus results, wherein said weld seam 8 by way of a groove-shaped portion which is delimited by the second flange regions 10 opens into the interior space 4.

(9) An end portion 11 of the cylinder shell, which faces the weld seam 8, on a face which faces the interior space 4 is configured so as to be cylindrical, that is to say to be free of any elevations or depressions. A portion having a plurality of grooves 13, which run along the circumference and are disposed in succession along the longitudinal axis 7, which becomes thicker toward the interior space 4 and is configured as a condenser 12 adjoins this end portion 11. A transition between the end portion 11 and the condenser 12 here has a transitional radius 14.

(10) Also, the cap 3 in the region of the weld seam 8 is configured so as to be cylindrical toward the interior space 4, so that the radially inward workpiece faces of both the cap 3 as well as of the cylindrical shell 2 on both sides of the weld seam 8 are configured so as to be cylindrical.

(11) As a result of the groove-shaped portion which opens out into the interior space 4 it is possible for the weld seam 8 having a substantially V-shaped cross section to be provided with a counter bead. Moreover, the cylindrical end portion 11 as well as the cylindrically configured and radially inward workpiece faces of both the cap 3 as well as of the cylinder shell 2, which are on both sides of the weld seam 8, enable simple checking of the weld seam 8 by visual means or by means of a suitable testing method using, for example, x-rays or ultrasound, or by means of color-penetration testing or magnetic powder testing.

(12) The weld seam 8 may also be configured so as to have a U-shaped, K-shaped, X-shaped, double-U-shaped or otherwise shaped cross section instead of a V-shaped cross section.

(13) In the embodiment which is exemplified in FIG. 3, a circumferential transitional groove 15 instead of a radius has been configured for the transition from the cylindrical end portion 11 to the condenser 12. The depth of said transitional groove 15 in the present case is equal to the depth of the grooves 13 of the condenser 12; however, said transitional groove 15 may also have a depth which is different from that of the grooves 13.

(14) By contrast, in the embodiment which is exemplified in FIG. 4, a wide step-like transitional groove 16 instead of the transitional groove 15 of FIG. 3 has been configured. The width of said transitional groove 16 is only limited by the width of the end portion 11. A transitional radius 17 is in each case provided between respective groove flanks of the transitional groove 16, which are perpendicular to the longitudinal axis 7, and a groove base of the transitional groove 16, which is parallel to the longitudinal axis 17.

(15) The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention: 1 Drying roller 2 Cylinder shell 3 Cap 4 Interior space 5 Hollow shaft 6 Journal 7 Longitudinal axis 8 Weld seam 9 First flange region 10 Second flange region 11 End portion 12 Condenser 13 Groove 14 Transitional radius 15 Transitional groove 16 Transitional groove 17 Transitional radius