EP4653612A1

EP4653612A1 - Sleeve roll for a wire section of a fiber web machine

Info

Publication number: EP4653612A1
Application number: EP24177629.3A
Authority: EP
Inventors: Kari Holopainen; Janne Virtanen; Sami Lamminparras; Antti RÄKKÖLÄINEN
Original assignee: Valmet Technologies Oy
Current assignee: Valmet Technologies Oy
Priority date: 2024-05-23
Filing date: 2024-05-23
Publication date: 2025-11-26
Also published as: CN121006718A

Abstract

The invention relates to a sleeve roll for a wire section of a fiber web machine, which sleeve roll (21) includes
- an axle beam (28) with an axle stub (53), the axle stub being supported in a bearing housing (54) equipped with a rocker bearing structure (56),
- two circular roll heads (29) and a belt loop (30) arranged around the axle beam (28) and tensioned between the roll heads (29),
- a convex forming element (22) for water removal, and
- adjustment means (60) configured to lock the axle beam (28) in place after adjustment of the forming element (22), the adjustment means (22) comprises an annular adjusting arm (64) with a support surface (62), the adjusting arm being attached to the axle stub (53), and an eccentric adjustment element (66) pivoted to the rocker bearing structure (56) for supporting the adjusting arm (64) in place, the adjustment element (66) being lockable in place to the rocker bearing structure (56) for locking the adjust4ment arm (64) and releasable for changing the position of the adjusting arm (64) .

Description

The present invention relates to a sleeve roll for a wire section of a fiber web machine, which sleeve roll includes

an axle beam with an axle stub, the axle stub being supported in a bearing housing equipped with a rocker bearing structure,
two circular roll heads supported on the axle beam and arranged to rotate,
a belt loop arranged around the axle beam and tensioned between the roll heads,
a convex forming element attached to the axle beam arranged between the axle beam and the belt loop, wherein the forming element is in contact with the belt loop to form rising pressure for water removal, and
adjustment means configured to lock the axle beam in place after adjustment of the forming element, the adjustment means comprises an annular adjusting arm with a support surface, the adjusting arm being attached to the axle stub.

EP-patent number 3913136 discloses a forming section of a fiber web machine. There is a sleeve roll having a belt loop arranged to rotate around an axle beam. Inside the sleeve roll there is a curvilinear forming element forming a dewatering zone. The increased pressure pushes water out the fiber web formed by the fiber web machine such as paper, board, pulp or tissue machines.
The position of the known forming element can be adjusted with adjustment means. The adjustment means include a screw that is used to adjust the position of the forming element by rotating the axle beam in relation to the rocker bearing structure that supports the axle beam. The adjustment is made using the screw to push an annular adjusting arm that is attached to the axle stub of the axle beam. The problem related to this kind of adjustment with the screw is that the screw is transmitting the torque affecting on it by the axle beam constantly, even when no active adjustment is being made. In other words, the screw and its threads are holding the axle beam in place and preventing it from turning around its bearings during operation of the sleeve roll. Thus, the forces affecting the threads of the screw are very substantial and it is very difficult to manufacture threads that are both accurate enough for the adjustment and strong enough to withstand the forces affecting on them. The combination of forces, demand of adjustment accuracy and operating condition regarding humidity create a challenging equation for implementation of the adjustment means. In practice, it has been found that the screw used in the sleeve roll of EP 3913136 tends to corrode and freeze solid or the threads tend to strip during the adjustment altering the adjustment means useless.
The object of the invention is to provide a sleeve roll for a wire section of a fiber web machine, which is more reliable in terms of adjustment than the prior art sleeve rolls. The characteristic features of the sleeve roll according to the invention are stated in the accompanying claims. The sleeve roll has new adjustment means which solve the above-mentioned problem. To be more precise, the adjustment means further includes an eccentric adjustment element pivoted to the rocker bearing structure for locking the adjusting arm in place, the adjustment element being lockable in place to the rocker bearing structure for locking the adjusting arm and releasable for changing the position of the adjusting arm.
The invention is described below in detail by referring to the enclosed drawings, which illustrate some of the embodiments of the invention, in which

Figure 1: shows a schematic side view of a forming section equipped with a sleeve roll according to the invention,
Figure 2: shows a side cross section view of one end of the sleeve roll according to the invention,
Figure 3: shows a cross section in cross direction of the sleeve roll according to the invention.
Figure 4: shows a partial horizontal cross section in machine direction of the adjustment means of the sleeve roll according to the invention,
Figure 5: shows a partial vertical cross section in machine direction of the adjustment means of the sleeve roll according to the invention,
Figure 6: shows a cross section of the support section of the support structure.

In the shown embodiment, the forming section includes a first wire loop 10 and a second wire loop 11 (Fig. 1). The first wire loop 10 circles over a forming roll 12 while the second wire loop 11 circles over a breast roll 13. The travel direction of the first wire loop 10 is designated with an arrow 14 and the travel direction of the second wire loop 11 is designated with an arrow 15. The first wire loop 10 and the second wire loop 11 form a converging gap 16 such that both wires loops 10 and 11 converge on the area of the forming roll 12. The forming section also includes a headbox 17 for feeding pulp suspension to the gap 16 between the wire loops 10 and 11. After the forming roll 12, there are three suction boxes 18, 19, 20 for water removal. Next there is the sleeve roll 21 according to the invention. Both wire loops 10 and 11 travel over the sleeve roll 21 equipped with a convex forming element 22 for water removal. Preferably the convex forming element is a curvilinear forming element.
The sleeve roll 21 is followed by a twin-wire section on which water is removed from the fiber web 23 travelling between the wire loops 10 and 11 with a suction box pair 24 being below the first wire loop 10. At the end of this twin-wire section, the travel direction of the second wire loop 11 is diverted with a second guide roll 25 and led to the return cycle. At the point of the second guide roll 25, the second wire loop 11 is separated from the first wire loop 10, in connection with which the fiber web 23 is attached with another suction box 26 to the first wire loop 10 and conveyed on the upper surface of the first wire loop 10 over a third guide roll 27 and then picked up to the following press section.
The sleeve roll shown in Figure 2 is for a wire section of a fiber web machine, as described above. The sleeve roll 21 includes a stationary axle beam 28 and two preferably circular roll heads 29 having axle stubs 53 supported on the axle beam 28 and arranged to rotate. Each roll head is preferably circular having a fixed radius. In addition, the sleeve roll 21 includes a belt loop 30 arranged around the axle beam 28 and tensioned between the roll heads 29. The circular roll heads 29 form the belt loop 30 in cylindrical shape especially when tensioned and rotating. Then the belt loop 30 can rotate around the axle beam 28. In addition, there is a curvilinear convex forming element 22 arranged between the axle beam 28 and the belt loop 30. The forming element 22 is in contact with the belt loop 30 to form rising pressure for water removal. In the invention the forming element urges the belt loop 30 locally outwards from its round form to follow the smaller radius forming element. The curved shape of forming element changes continuously or stepwise shorter in radius.
The sleeve roll according to the invention enables of adjustment of the forming process by changing the position (also known as the outstick) of the forming element. Here, the end of the axle 28 has also a bearing housing 54 and there is adjustment means 60 between the axle 28 and a rocker bearing structure 56 belonging to the bearing housing 54. Thus, the alignment of the sleeve roll can be fine adjusted. Then the wearing of the belt loop and wire loops are minimized, and the water removal is maximized. This turning adjustment is illustrated in Figure 1. The adjustment means are described in more detail later in the description.
Figure 2 shows the basic components of the sleeve roll 21, but only part of the outline of the belt loop 30 itself. The belt loop 30 is tensioned by moving at least of one of the roll head 29 axially. The roll head is preferably equipped with a tension device having hydraulic conducts inside the axle and a center bore arranged to the axle. The structure is simple, and the tension of the belt loop can be adjusted precisely and apart from other adjustments of the sleeve roll. The tension device can be a double-action cylinder connected to the roll head. The roll head is preferably in two parts. The first part is an inner ring, which is non-rotating, but can slide axially. The second part is an outer ring which is rotary by the bearing. Thus, the belt loop can be adjustable tensioned even during the rotation.
The roll head preferably has a bearing with a separate lubrication. In other words, the lubrication of the bearing is separated from the lubrication of the sliding element and the forming element.
According to an embodiment the forming element is arranged, in addition to movable, also tiltable in relation to the axle beam. The forming element can be pivoted at its front end and it is urged against the belt loop by preferably hydraulic devices. Alternatively mechanical devices such as a screw can be used.
The axle beam can be polygonal in cross section. Thus, the axle beam is rigid and can be positioned in any angle.
The forming element is preferably convex, and it protrudes out of the circular belt loop. By urging the forming element tensions the belt loop in both machine direction and cross machine direction while no other roll is involved. The protrusion of the forming element is on its maximum advantageously smaller than 120 mm, advantageously 30 - 90 mm. The sliding surface can be arranged also inwards from the belt radius to form an indent support for the belt loop which reduces the amount of protrusion outwards of the forming element. Said arrangement reduces the local elongation of the belt and can help to increase the belt lifetime. The first part is a base part which is pivoted to the axle beam. The second part is contact part which is replaceable fixed to the base part. Thus, simply by changing the contact part, to features of the sleeve roll can be tuned. The fine adjustment can be made using the adjustment means according to the invention.
There is fabric tension wrap over the sleeve roll before forming element which can be handled with a lubricated sliding surface prior to the forming element. The sliding surface and the forming element create together a friction surface on the area of the fabric tension wrap. The wrap against the sleeve roll is advantageously 60 - 160 degrees. The sliding surface makes the axle more rigid against bending when properly joined. Also, the sliding surface can be lubricated against friction and there are lubrication showers prior to sliding surface and and/or through said surface. The fabric tension against the belt loop on the sliding surface during wrap over it arranges the driving power to the sleeve roll. Lubricant is fluid, preferably oil. Also compressed air or mixture of air and oil or even water can be used, especially with the fluid pockets of the sliding surface.
The axle beam can be made of hollow polygonal and/or round beam structure giving support to forming element and other devices and have room inside the belt loop for said equipment. Said axle beam is preferably made of polygonal, say 6 - 12 rounded corners, beam structure with axle stubs attached to it. The polygonal form comes preferably from bended metal plates which are welded together from at least two pieces. Alternatively casting of the axle beam may be used. Stationary polygonal axle beam is rigid to large angle of tension forces from both belt loop together with the forming element protrusion and fabric wrap. Surprisingly, both high I-shaped and simple square beams meant to press nips were poor for sleeve roll solutions with varying angle of forces. Metal plate thickness is advantageously 30 - 60 mm. Axle structure according to invention is a polygonal and curved closed beam close to belt loop wherein curved part is contouring the belt run supporting it. The axle is designed for loading requirements of large wire tension wrap over sliding surface and forming element. Moreover, there is room for forming element and belt supports outside the axle beam and it also fit forming element moving equipment and fluid connections inside the axle. Said axle can have opening and hatches for service of the devices inside the axle beam.
The roll heads are supported with sliding means from the stationary axle stub. There are means for moving the roll head axially advantageously hydraulic cylinder means attached to the roll head and placed inside the axle beam. There are also indexing means in connection with the bearing housing outer side of the roll head. Then it is possible to tune the alignment of the sleeve roll. At least one of the roll heads has opening through the axle stub for lubrication oil inlets and outlets. Said opening is sealed so that air pressure inside the belt can be increased.
As stated earlier the sleeve roll 21 includes adjustment means 60 for adjusting the axle beam 28 and the forming element 22 via the axle stub 53 using the adjusting arm 64 shown in Figure 3. The position of the convex forming element 22 shown in Figure 2 can be adjusted by rotating the axle beam 28 via its axle stub 53 using the adjustment means 60. The adjustment means 60 for implementing the adjustment has been shown in Figure 3. The adjusting arm 64 has been attached to the axle stub 53, preferably by using an annular attachment flange 65 that is connected around the axle stub 53. Preferably the adjusting arm 64 arm has corresponding counter member to be fitted against the annular attachment flange 65. The attachment flange 65 can be fixed to the axle stub 53, for example with wedges 67 or in other suitable manner. The attachment flange 65 may have a toothing or similar that can be used to transmit torque between the adjusting arm 64 and the axle stub 53.
The position of the axle stub 53 and the adjusting arm 64 attached to it is locked using an eccentric adjustment element 66 that is included in the adjustment means 60. The eccentric adjustment element 66 is supported against the support surface 62 of the adjusting arm 64. The adjustment element 66 is eccentric in the sense that the shape of the adjustment element 66 is such that when rotated, the position wherein the adjustment element 66 supports the adjusting arm 64 changes. Thus, by rotating the adjustment element, the position of the forming element can be changed via the adjusting arm. Each rotational position of the eccentric adjustment element corresponds to an individual position of the adjusting arm and thus the forming element.
Figure 3 disclose a preferable embodiment of the invention wherein the support surface 62 of the adjusting arm 64 is a slot 76 formed in the adjusting arm 64. The longest dimension of the slot is in the radial direction of the sleeve roll. The width of the slot 76 corresponds to the diameter of the adjustment element 66 in every possible position of the adjustment element 66 so that there is only minimal play in between the parts, the play being in the order of 10 - 40 µm. Practically there is no actual play with these parts and the minimal play is there for installation purposes only. The advantage of the slot 76 as the support surface 62 is that the locking of the adjusting arm 64 can be implemented with using only a single adjustment element 66 as the support surfaces 62 are formed on both sides of the slot 76. The length of the slot 76 in the radial direction of the sleeve roll is larger than the width of the slot 76 so that dimension changes of the adjusting arm 64 and deflection of the sleeve roll will not cause any forces to the adjustment element 66.
A preferred embodiment of the adjustment element 66 is shown in Figures 3 - 5. The eccentric adjustment element 66 includes a support structure 68 to be supported against the support surface 62 of the adjusting arm 64 and a shaft 70, that is used for attaching the support structure 68 to the rocker bearing structure 56. The shaft has two ends 72, one of which is inserted into the rocker bearing structure 56 and the other one is used for supporting the support structure 68. The support structure 68 has a first locking bore 80 and the shaft 70 has a second locking bore 81. In addition, the adjustment element 66 includes a locking pin 82 to be inserted through the first locking bore 80 to the second locking bore 81 of the shaft 70 for locking of the support structure 68 to the rocker bearing structure 56 via the shaft 70. It is preferred to have the adjustment element 66 made of two separate parts, namely the support structure 68 and the shaft 70, so that whenever the position of the adjustment element 66 is changed, only the support structure 68 in contact with the support surface 62 of the adjusting arm 64 is released and rotated while the shaft 70 remains in place attached to the rocker bearing structure 56. The support structure 68 forms a counter support surface 71 that is supported against the support surface or surfaces 62 of the adjusting arm 64.
Another advantage of the adjustment element 66 made of two separate parts is that the parts can be made of different materials enabling more cost-efficient material selections. By using two different materials the seizing of the two parts can be avoided as well.
Preferably the shaft is made of duplex or martensite, whereas the support structure is made of acid-durable steel and the locking pin is made of high strength brass or bronze. These materials have found to have the adequate strength to withstand forces affecting on them and to endure the demanding circumstances with heat and chemicals affecting on the structure. Other materials can also be used taking into account the requirements of the operating environment.
As can be seen from Figure 4, the support structure 68 is preferably a nut, that has an eccentric support section 73 wherein the counter support surfaces 71 of the adjustment element 66 are formed and a flange 75 which is used for transverse support of the adjustment element 66. Preferably the flange is a symmetric structure. The eccentricity of the adjustment element 66 is formed in the eccentric support section 73, wherein the distance between the counter support surface 71 and the center point c of the shaft 70 is different in each counter support surface 71. In other words, the length of a line L that is perpendicular to the plane of the counter support surface 71 and runs through the center point c of the shaft 70 is different for each counter support surface 71. For example, in an octagon shaped support section 7, shown in Figure 6 the diameter of the eccentric support section 73 can be 100 mm, and each counter support surface 71 is 1 mm further away from the center point c of shaft than the adjacent counter support surface 71, namely the distances being, 45, 46, 47, 48, 49, 50, 51 and 52 mm. The eccentricity e1 to e8 of each counter support surface is different. In other words, the adjustment element is asymmetric. Preferably, the flange and shaft have both a round cross section.
There can be at least two separate, preferably 4 - 10, most preferably 8 alternative counter support surfaces 71. In the Figures 3 and 6 the eccentric support section 73 of the adjustment element 66 includes 8 separate counter support surfaces 71 each corresponding to a different position of the convex forming element when placed against the support surface or surfaces 62 of the adjusting arm 64. The eccentric support section 73 can cause, for example, the following settings of the convex forming element, 0°; + 0,1°; + 0,2°; + 0,3°; + 0,4°; + 0,5°; + 0,6°; and + 0,7°.
The advantage of using planar counter support surfaces is that as the support section is dimensioned to correspond to the dimensions of the slot of the adjusting arm, the planar counter support surfaces resist the adjustment element's tendency to turn around the shaft. The shaft is the pivot point as the eccentricity of the counter support surfaces act as a torque arm and the adjusting arm is transmitting the force of the axle beam to the adjustment element.
Figure 4 shows the horizontal cross section of the adjustment element 66. The support section of the support structure 68 of the adjustment element 66 is preferably a hollow structure placed on top of the end 72 of the shaft 70. Thus, the eccentric support section 73 of the support structure 68 is supported on the shaft 70 using a large surface area providing a rigid and reliable connection.
Preferably the adjustment element 66 is supported on the rocker bearing structure 56 using a support frame 74, that is attached to the rocker bearing structure 56. Bolts can be used for attaching the support frame 74 to the rocker bearing structure 56. As one end of the shaft 70 of the adjustment element 66 is fitted inside a third bore hole 86 formed in the rocker bearing structure 56, a partial length of the shaft 70 extends outside the third bore hole 86. Large lateral forces caused by the adjusting arm 64 are affecting this part of the shaft 70. To counter these forces the adjustment element 66 is preferably supported also from the support structure 68 to the rocker bearing structure 56 via the support frame 74. More precisely the flange 75 of the support structure 68 is supported on the support frame 74. For this purpose, the support frame 74 has aperture shaped and dimensioned to fit the flange 75 of the adjustment element 66. With the aid of support frame 74, the adjustment element 66 can be supported from both ends, i.e. two separate areas, thus eliminating any torsion of adjustment element 66.
The cross-section of the support frame 74 can be seen in Fig-ure 4. The support frame 74 preferably forms a closed loop structure within which the adjusting arm 64 and the adjustment element 66 are fitted. The support frame 74 includes two axial parts 88 at a distance from each other extending in the axial direction of the sleeve roll and at least one transverse part 90 connecting the axial parts 88 together. In the preferred embodiment of Figure 4, there are two transverse parts 90 at a distance from each other in axial direction of the sleeve roll. The axial parts 88 and the transverse parts 90 form a closed loop structure which can be attached to the rocker bearing structure 56. The closed loop structure is very rigid. The adjustment element 66 extends through the support frame 74 and is supported by the support frame 74 in at least one area of the adjustment element 66, preferably at an end of the adjustment element 66. Preferably there is a space between the adjusting arm 64 and the support frame 74 also in axial direction of the sleeve roll so that deflection or deformation of the bearing housing 56 does not create any forces on the adjusting arm 64.
Preferably the sleeve roll has a set of adjustment elements consisting of 2 - 6 said adjustment elements, each adjustment element having different shape and amount of eccentricity for achieving different position of the convex forming element. If each adjustment element has eight separate counter support surfaces, each counter support surface causing a difference of 0,1 - 0,2° relative to its adjacent counter support surface, an adjustment range of ± 2° of the convex forming element in circumferential direction of the belt loop can be achieved by using preferably three separate adjustment elements, each having unique range of eccentricity.
According to an alternative solution the support section of the adjustment element has a uniform and continuous counter support surface with no planar surfaces, the uniform counter support surface being shaped so that the eccentricity of the counter support surface is constantly changing. In other words, the support section can be elliptic or otherwise asymmetric in shape whereas the support section shown in Figures 3 - 5 is an octagon with planar counter support surfaces. In the alternative embodiment, it may be required that the support surface of the adjusting arm has interchangeable curved support surface sections, each section corresponding to a certain curvature of the support section of the adjustment element. This may be required to prevent the adjustment element 66 from rotating unintentionally by the torque affecting on it by the adjusting arm 64.
The embodiment with the planar counter support surfaces is preferred over the uniform and continuous counter support surface because when using a curved shape of the uniform counter support surface, the contact surface between the counter support surface and the support surface of the adjusting arm is very small causing a large surface pressure on the counter support surface. The planar counter support surface has a much larger surface area and thus lower surface pressure, which is preferred to improve the robustness and wear resistance of the adjustment element.
Preferably the support frame 74 further includes two rotation supports 84 shown in Figure 4 placed on both sides of the adjusting arm 64 and in between the axial parts 88 of the support frame 74, the rotation support 84 being rotatable for supporting the adjusting arm 64 to maintain its position when the adjustment element 66 is released. The main adjustment is done by using an external force such as using a crane or other type of external force to rotate the axle beam. In other words, the rotation supports form a temporary support surface against the adjusting arm when the adjustment element is released. It should be noted that when the adjustment element is locked in place again, the rotation supports 84 are moved further away from the adjusting arm 64 and do not support the adjusting arm during operation of the sleeve roll or at least do not transmit any torque.
The use of support frame is especially advantageous in an embodiment wherein only one adjustment element is used. The single adjustment element must withstand the forces alone and thus the use of support frame for supporting the adjustment element from two areas is preferred.
The adjustment of the convex forming element can be made according to the following steps. The first step is to loosen the locking of the support structure 68 of the adjustment element 66 by releasing the locking pin 82. The locking pin 82 is preferably a bolt tightened on counter threads (not shown) formed in the shaft 70 as shown in Figures 4 and 5 and can be loosened by turning the locking pin 82. The shaft 70 itself can also be fitted to the rocker bearing structure 56 using threads. Once the locking pin 82 is unscrewed the support structure 68 can be pulled away from the shaft 70 in the axial direction of the shaft 70. For this purpose, a separate pulling tool can be used which has threads corresponding to the threads of the support structure 68.
After support structure 68 has been pulled outside the periphery of the support surface 62 of the adjusting arm 64, which is preferably the slot 76, the axle beam 28 and the adjusting arm 64 can be rotated around the bearing housing 54 to adjust the position of the convex forming element 22 for example by using a crane or the rotation supports 84 shown in Figure 4. Once the adjustment has been made and desired position of the forming element has been reached, the support structure 68 of the adjustment element 66 is rotated to the corresponding position so that the eccentric support section 73 of the support structure 68 and the support surface 62 of the adjusting arm 64 align with each other. The support structure 68 is then pushed back in contact with the shaft 70 and in contact with the support surface 62 of the adjusting arm 64 and locked in place using the locking pin 82.
It must be understood that the sequence of rotation of the adjusting arm and the rotation of the adjustment element can also be made in opposite order.
It must be understood that the adjusting of the position of the axle beam is made only when the forming section is not running.
According to an embodiment, the sleeve roll can also have more than one adjustment means for adjusting the forming element. A single end of the sleeve roll may have two adjusting arms and corresponding adjustment elements for each adjusting arm. Alternatively, both ends of the sleeve roll may have adjustment means. However, it is preferred to not to have the adjustment means on the end of the sleeve roll wherein the drives of the rolls are located as the space there is very limited and service is difficult. The use of two adjusting arms and adjustment elements in one end may be used to reduce the surface pressure between the support surface of the adjusting arm and the counter support surface of the adjustment element.
According to yet another alternative embodiment, the adjustment means can be implemented using an adjusting arm with two support surfaces arranged at both sides of the adjusting arm and two adjustment elements fitted on both sides of the adjusting arm for locking the adjusting arm in between the adjustment elements. However, this embodiment is more expensive to implement than the preferred embodiment implemented with one adjustment element and an adjusting arm having a slot because the alternative embodiment needs two adjustment elements and also more complicated to use as it requires the rotation of two adjustment elements.
Sleeve roll diameter is advantageously 700 - 1600 mm. The length of the adjusting arm can be 350 - 700 mm.

Claims

Sleeve roll for a wire section of a fiber web machine, which sleeve roll (21) includes
- an axle beam (28) with an axle stub (53), the axle stub being supported in a bearing housing (54) equipped with a rocker bearing structure (56),

- two circular roll heads (29) supported on the axle beam (28) and arranged to rotate,

- a belt loop (30) arranged around the axle beam (28) and tensioned between the roll heads (29),

- a convex forming element (22) attached to the axle beam (28) arranged between the axle beam (28) and the belt loop (30), wherein the forming element (22) is in contact with the belt loop (30) to form rising pressure for water removal, and

- adjustment means (60) configured to lock the axle beam (28) in place after adjustment of the forming element (22), the adjustment means (60) comprises an annular adjusting arm (64) with a support surface (62), the adjusting arm being attached to the axle stub (53),
characterized in that the adjustment means (60) further include an eccentric adjustment element (66) pivoted to the rocker bearing structure (56) for supporting the adjusting arm (64) in place, the adjustment element (66) being lockable in place to the rocker bearing structure (56) for locking the adjusting arm (64) and releasable for changing the position of the adjusting arm (64).
The sleeve roll according to claim 1, characterized in that the adjustment element (66) is shaped to support the adjusting arm (64) in different position in different rotation orientation of the adjustment element (66).
The sleeve roll according to claim 1 or 2, characterized in that the adjustment element (66) includes
- a support structure (68) to be supported against the support surface (62) of the adjusting arm (64), the support structure (68) having a first locking bore (80),

- a shaft (70) for attaching the support structure (68) to the rocker bearing structure (56), the shaft having two ends (72), and a second locking bore (81) and

- locking pin (82) to be inserted in the first locking bore (80) and second locking bore (81) for locking of the adjustment element (66) to the rocker bearing structure (56).
The sleeve roll according to claim 3, characterized in that at least the support surface (62) of the adjusting arm (64) is made of acid-resistant steel and the adjustment element (66) is made of high strength brass or bronze to avoid seizing of the adjustment element (66).
The sleeve roll according to claims 3 or 4, characterized in that the eccentric adjustment element (66) has at least two separate, preferably 4 - 10, most preferably 8 alternative counter support surfaces (71) to be placed against the support surface (62) at selected orientation of the adjustment element (66).
The sleeve roll according to claim 5, characterized in that each counter support surface (71) has an individual amount of eccentricity.
The sleeve roll according to claim 5 or 6, characterized in that each counter support surface (71) is a plane that is perpendicular to the radial direction of the shaft of the adjustment element (66).
The sleeve roll according to any of claims 2 - 7, characterized in that the sleeve roll (21) has a set of adjustment elements (66) consisting of 2 - 6 said adjustment elements (66), each adjustment element (66) having different shape of achieving different position of the convex forming element (22).
The sleeve roll according to claim 8, characterized in that the set of adjustment elements (66) is arranged to achieve the adjustment ± 2° of the convex forming element (22) in circumferential direction of the belt loop (30) with steps of 0,1 - 0,2°.
The sleeve roll according to any of claims 1 - 9, characterized in that the actuating means include a support frame (74) attached to the rocker bearing structure (56) for supporting the adjustment element (66) from one end (72) to the rocker bearing structure (56) and from the other end (72) to the support frame (74).
The sleeve roll according to claim 10, characterized in that the support frame (74) has axial parts (88) having a space in between for the adjusting arm (74) and the support frame (74) and a transverse part (90) attached to the axial parts (88) for forming the support for the shaft (70) of adjustment element (66).
The sleeve roll according to claim 11, characterized in that the support frame (74) has two rotation supports (84) placed on both sides of the adjusting arm (64) placed in between the axial parts (88) of the support frame (74) the rotation support (84) being rotatable for supporting the adjusting arm (64) during rotation of the adjustment element (66).
The sleeve roll according to any of claims 3 - 12, characterized in that the support structure (68) includes an eccentric support section (73) to be supported against the support surface (62) of the adjusting arm (64) and a flange (75) to be supported against the support frame (74).
The sleeve roll according to any of claims 1 - 13, characterized in that the support surface (62) is a slot (76) formed in the adjusting arm (64) in the radial direction of the sleeve roll (21) and the eccentric adjustment element (66) is arranged to be fitted in the slot (76) as the adjusting arm (64) is locked in place.