Brake of an Idler Roll of a Fiber Web Machine, in particular of a Slitter-winder

Abstract

A brake is provided for an idler roll (10) of a fiber web machine, in particular of a slitter-winder, which idler roll (10) has an outer shell surface (13). The brake (20) is located outside the outer shell surface (13) of the idler roll (10) in close vicinity of the idler roll (10) in a non-contacting position. The brake (20) has a permanent magnet (25), which is configured to be moved from non-braking position to a braking position and vice versa by an actuator or cylinder (35, 45).

Claims

1. An idler roll brake in a fiber web machine, comprising: an idler roll having an outer shell, the outer shell having an outer shell surface; a brake located outside the outer shell surface of the idler roll; and wherein the brake comprises a permanent magnet arranged to be moved by an actuator from a non-braking position spaced from the outer shell surface of the idler roll to a braking position near but not in contact with the outer shell surface, the actuator also arranged to move the brake back to the non-braking position spaced from the outer shell surface.

2. The idler roll brake of claim 1 wherein the fiber web machine is a slitter-winder.

3. The idler roll brake of claim 1 wherein the brake further comprises a frame, the frame having portions defining an inner hollow opening forming a chamber; and wherein the permanent magnet is movably located inside the chamber and configured to be moved therein from the non-braking position to the braking position and back to the non-braking position.

4. The idler roll brake of claim 3 wherein the frame further comprises a chamber frame and a cover frame forming an outer structure of the brake which holds and guides the permanent magnet as the permanent magnet moves toward and away from the outer shell of the idler roll.

5. The idler roll brake of claim 4 wherein the chamber frame has a cylindrical form, and the chamber has a cylindrical form within the chamber frame.

6. The idler roll brake of claim 4 wherein the cover frame is attached to the chamber frame so as to be openable to give access to the chamber.

7. The idler roll brake of claim 4 wherein the chamber holds a brake support element to which the permanent magnet element is mounted.

8. The idler roll brake of claim 7 wherein the chamber has an inner wall, and the brake support element has an outer wall and wherein the inner wall of the chamber is sealed to the outer wall of the brake support element by a seal.

9. The idler roll brake of claim 4 wherein the brake frame is made of polymeric material.

10. The idler roll brake of claim 1 wherein in the non-braking position the permanent magnet is spaced from the outer shell surface of the idler roll a distance of 4.9 to 10 mm, and in the braking position the permanent magnet is spaced from outer shell surface a distance of 0.1 to 2 mm.

11. The idler roll brake of claim 1 wherein the actuator is a piston that moves in a cylinder.

12. The idler roll brake of claim 1 further comprising a control device arranged to switch the braking on and off by movement of the permanent magnet.

13. The idler roll brake of claim 1 wherein the permanent magnet is moved from the non-braking position to the braking position by a stroke movement of the actuator of 5-50 mm.

14. The idler roll brake of claim 1 wherein the brake has a diameter of 30-100 mm and a height of 30-100 mm.

15. The idler roll brake of claim 1 wherein the distance between the brake and the outer shell surface of the idler roll is 0.1 to 10 mm and the braking position of the brake places the permanent magnet 0.1-2 mm from the outer shell surface of the idler roll.

16. An idler roll brake in a fiber web machine, comprising: an electrically conductive idler roll having an outer shell, the outer shell having an outer shell surface; a brake comprising a permanent magnet located outside the outer shell surface of the idler roll; and wherein the permanent magnet is mounted for movement by an actuator to move from a position spaced at least 5 mm from the outer shell surface of the idler roll to a position where the permanent magnet interacts with the electrically conductive idler roll to stop the rotation of the electrically conductive idler roll in less than 2 minutes.

17. The idler roll brake of claim 16 wherein the idler roll is an aluminum roll and wherein the permanent magnet is mounted for movement by the actuator to move the permanent magnet to a position of 0.1 to 2 mm from the outer shell surface of the idler roll to stop the rotation of the idler roll.

18. A braking apparatus in a fiber web machine including an idler roll having an outer shell with an outer shell surface, the braking apparatus comprising: an actuator having an extensible piston, the piston being extensible in a radial direction with respect to the idler roll; and a permanent magnet mounted to the extensible piston and spaced from the outer shell surface, the actuator arranged to move the permanent magnet on the piston between a non-braking position located a first distance from the outer shell surface to a braking position located a second distance from the outer shell surface, wherein the second distance is less than the first distance and wherein at the second distance the permanent magnet is not in contact with the outer shell surface, wherein the braking apparatus is located outside the outer shell surface of the idler roll.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Aspects of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of some example embodiments when read in connection with the accompanying drawings and in the following the invention is described in more detail referring to the accompanying drawings.

[0038] FIG. 1 is schematically shown an example of an idler roll of a slitter-winder with an advantageous example of the brake according to the invention.

[0039] FIG. 2 is schematically shown the advantageous example of the brake according to FIG. 1, when it is not braking.

[0040] FIG. 3 is schematically shown the advantageous example of the brake according to FIGS. 1-2, when it is braking.

[0041] FIGS. 4 and 5 schematically shown the example of FIG. 1 as 3D views.

[0042] FIG. 6 is schematically shown another advantageous example of the brake according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] During the course of this description like numbers and signs will be used to identify like elements according to the different views which illustrate the invention. Repetition of some reference signs may have been omitted in the figures for clarity reasons.

[0044] In FIGS. 1 and 4-6 is shown an idler roll 10 with a brake 20. The idler roll 10 comprises an outer shell surface 13 and a mounting frame 12, to which the brake 20 is attached by a fastener 29 such that the brake 20 is located outside the outer shell surface 13 of the idler roll 10 in close vicinity of the idler roll 10 in a non-contacting position i.e., the brake 20 is not in contact with the outer shell surface 13 of the idler roll 10. The brake 20 comprises a permanent magnet 25, which is movable from a non-braking position to a braking position and vice versa, by an actuator, which in the example of FIGS. 2-5 is a piston 35 and in the example of FIG. 6 a permanent magnet is connected by a rod 45 to a piston in a cylinder.

[0045] In FIG. 2 is shown the brake 20 in a non-braking position and in FIG. 3 is shown the brake 20 in a braking position. The brake 20 has a frame 21, 22, advantageously formed openable and comprising a chamber frame 22 and a cover frame 21, which form the outer structure of the brake 20. The chamber frame 22 has a cylindrical form. The cover frame 21 is openably attached to the chamber frame 22, for example by a threaded connection 32. When mounted in connection with an idler roll 10 as shown in FIGS. 1 and 4-5 the cover frame 21 of the brake 20 is towards the outer shell surface 13 of the idler roll 10.

[0046] The distance between the brake and the outer shell surface of the idler roll 10 is 0.1-10 mm, advantageously 0.1-2 mm at the closest point in the braking position.

[0047] The chamber frame 22 has inside a hollow non-though opening with a bottom 31 and a chamber 23 formed by the inside of the chamber frame 22 and the cover frame 21 closes the opening and thus, a closable chamber 23 is formed. The chamber 23 has a cylindrical form. Inside the chamber 23 is located a brake support element 24 with a permanent magnet element 25. The inner wall of the chamber 23 and the outer wall of the brake support element 24 is sealed by a seal 27 so fluid e.g., air can move the brake support element 24 and permanent magnet element 25. The brake 20 has a fluid connection 26 configured to provide pressurized fluid, advantageously pressurized air, to the closed chamber 23 from below the brake support element 24 for moving the brake support element 24 and the permanent magnet 25 inside the chamber 23 towards the cover frame 21 and thus, towards the idler roll 10 to be braked, when braking by the brake 20 is required. The fluid connection 26 is also configured to provide suction for removing the pressurized fluid, advantageously pressurized air, from below the brake support element 24 for moving the brake support element 24 and the permanent magnet 25 inside the chamber 23 towards the bottom 31 and thus, away from the idler roll 10, when braking by the brake 20 is not anymore required. In the brake 20 the permanent magnet 25 is configured to create the braking effect when moved to be in contact with the cover frame 21 of the brake 20 i.e., to the closest position in view of the outer shell surface 13 of the idler roll 10. As can be noted, the brake 20 comprises as the actuator a piston 35 and thus has advantageously a piston braking principle and is thus advantageously a piston brake 20 the braking effect is provided by the permanent magnet 25.

[0048] The brake 20 advantageously comprises control device 28 e.g., a fluid valve, to switch the braking on and off by provide the pressurized fluid into the chamber and by removing the pressurized fluid from the chamber, via the fluid connection 26.

[0049] The stroke of the permanent magnet 25 in its movement from the non-braking position to the braking position is short, advantageously 5-50 mm.

[0050] The chamber frame 22 and the cover frame 21 are advantageously of polymeric material and can be advantageously produced by 3D printing.

[0051] The brake 20 is a compact element and has diameter of 30-100 mm and height of 30-100 mm.

[0052] In FIG. 6 is shown another example of the brake 20. The brake 20 comprises the same features, fastening structures, movement principles and functions as in the above example but in this example the overall structure of the brake 20 is simplified. The brake 20 comprises the permanent magnet 25, which in this example is movable by the actuator or piston, with a cylinder 45 or actuator, advantageously a short-stroke cylinder.

[0053] In the description in the foregoing, although some functions have been described with reference to certain features, those functions may be performable by other features whether described or not. Although features have been described with reference to certain embodiments or examples, those features may also be present in other embodiments or examples whether described or not. Above the invention has been described by referring to some advantageous examples only to which the invention is not to be narrowly limited. Many modifications and alterations are possible within the invention as defined in the following claims.