WO2009153401A1

WO2009153401A1 - Roll arrangement and slitter- winder of fibrous-web machine

Info

Publication number: WO2009153401A1
Application number: PCT/FI2009/050525
Authority: WO
Inventors: Marko Jorkama
Original assignee: Metso Paper Oy
Current assignee: Valmet Technologies Oy
Priority date: 2008-06-18
Filing date: 2009-06-17
Publication date: 2009-12-23
Anticipated expiration: 2010-12-18
Also published as: FI20085600L; FI20085600A0; FI122033B

Abstract

The present invention relates to a roll arrangement (50) of a fibrous-web machine, which comprises at least one roll (51, 52) and a bearing system (100) at both ends of said roll (51, 52) provided with fastening elements via which the bearing system and by that the roll (51, 52) are supported. The fastening elements (115) of the roll bearing system (100) are rigidly fastened in a mass body (125) and said mass body (125) is elastically and dampingly arranged into connection with a surrounding foundation (30).

Description

Roll arrangement and slitter-winder of fibrous-web machine

[001] The invention relates to a roll arrangement of a fibrous-web machine according to the preamble of claim 1 , which comprises at least one roll and a bearing system at both ends of said roll provided with fastening elements via which the bearing system and by that the roll are supported. The invention also relates to a slitter-winder according to the preamble of claim 6.

[002] As the widths of fibrous-web machines are increasing and their speeds rising, the vibration of rolls becomes a problem greater than ever. Rolls are used in fibrous-web machines e.g. for controlling the travel of the web and/or support fabric. More substantial from the viewpoint of the properties of the fibrous web are still such operating positions in which the roll participates in processing the web, such as roll nips, calender rolls, coating counter rolls and winding rolls or cylinders. Particularly, the winding rolls and carrier rolls of slitter-winders used in the finishing of the web are demanding targets as to vibration, because the winding of customer reels of various sizes and possibly including different flaws is easily disturbed due to excessive vibration.

[003] Vibration is a problem particularly on slitter-winders of carrier-roll or carrier-belt type. A vibration problem occurring on the carrier-roll slitter-winder arises when a multiple of the rotational frequency of a paper roll being formed on the carrier rolls excites the natural frequencies of the carrier rolls. A similar vibration problem also occurs on the winding rolls of wind-ups. In general, resonance vibrations during the operation of the machine or device are caused by inadequate damping i.e. inadequate dynamic rigidity on the resonance frequency. The situation is often improved by modifying the resonating structure directly such that its damping increases.

[004] Fl patent 94458 describes a method and apparatus for controlling the vibration of the rolls of a paper machine. In the method, the positions of the critical speed ranges of the roll are changed during run. Critical speed is changed by altering the mass and/or the rigidity of the roll and/or the support point of the roll. As a possibility is presented altering the rigidity of the end bearing of the roll. Between the washer of the bearing housings of the end bearings and the frame, intermediate pieces of elastic material can be installed. By adjusting the force with which the bearing housing presses the intermediate pieces against the frame, it is possible to adjust the rigidity of the fastening of the bearing housings. Said pressing force can be adjusted by means of a cylinder device or a screw.

[005] JP patent specification 3082843 describes an arrangement for minimising vibrations in a roll. The drive motor of the roll is elastically fastened in the frame. The fastening comprises a rubber intermediate piece enduring vibration between the base plate of the fastening section of the drive motor and the frame. The fastening bolts of the base plate extend through the frame plate into a cylinder fastened on the lower surface of the frame plate in which they are fastened in a piston in the cylinder. There are rubber sleeves below the fastening bolt heads, whereby the fastening of the base plate is provided floating. On the inner surface of the cylinder, there is a projection which limits the upward motion of the piston in the cylinder. Between the cylinder head and the upper surface of the piston, there is a spring and, between the lower surface of the piston and the bottom of the cylinder, there is a pressure space in which the pressure medium is compressed air. The piston is run with compressed air first against the projection of the inner surface of the cylinder, whereby a minimum pressing force is applied on the rubber intermediate pieces and sleeves. When the pressure of compressed air below the piston is decreased, the piston moves downwards from the force of the spring being above the piston, whereby a greater pressing force is applied on the rubber intermediate pieces and rubber sleeves. With the pressure of pressure medium being below the piston, it is then possible to adjust the rigidity of the fastening of the roll.

[006] Fl patent 118482 describes supporting a roll of a paper or board machine in which the roll is supported of its ends rotatably on bearings in bearing housings and which bearing housings are supported on the machine frame or foundation via elastic intermediate pieces. The specification discloses a particular advantageous variation range for the spring constant of the intermediate pieces. This arrangement increases the damping capacity of an elastic, poorly damped structure by changing the boundary conditions of the structure such that damping is introduced to the structure being damped via fastenings. The static rigidity of the structure and its support then decreases, but the dynamic rigidity of the actual structure increases. A disadvantage of such an arrangement is that the used bearing housing requires a special bearing housing construction usually demanding a lot of space.

[007] Fl patent 1170902 describes a foundation arrangement of a fibrous-web machine or equivalent, by means of which the frame of a fibrous-web machine section or device is supported on the construction.

The specification depicts that the frame is supported via a stationary massive base on the foundations such that the base has been supported via a moving coupling to the construction foundation. This arrangement can only effectively act on a part of the whole fibrous-web machine, because the whole frame is supported via the same base. However, this has no considerable effect on the vibration damping of a single roll being supported on the frame.

[008] Even though the above arrangements are advantageous as such, now there are requirements to improve the vibration damping of single rolls. Therefore, the object of this invention is particularly to improve the prior art prevailing in the field by introducing such a roll arrangement of a fibrous-web machine by means of which it is possible to effectively act on the roll vibrations.

[009] A roll arrangement of a fibrous-web machine for damping vibrations of a roll according to a first embodiment of the invention, which comprises at least one roll and a bearing system at both ends of said roll provided with fastening elements via which the bearing system and by that the roll are supported. It is characteristic of the roll arrangement that the fastening elements of the roll bearing system are rigidly fastened in a mass body and that said mass body is elastically and dampingly arranged into connection with a surrounding foundation.

[0010] Such an arrangement provides a particularly effective damping of roll vibrations. The arrangement is particularly advantageous with rolls which participate in forming the web reel. Then, the web reel or reels apply very large forces to the roll which include extremely intensive dynamic variations and the arrangement according to the invention is also able to effectively damp vibration in such a situation.

[0011] The mass body is arranged into connection with the foundation such that between the mass body and the foundation is fitted an elastic element. With the separate elastic element, the damping properties of the arrangement can be set according to the requirements of each case. The elastic element is advantageously arranged between an opposite surface in relation to a fastening surface of the roll of the mass body and the foundation.

[0012] The elastic element is a viscoelastic flexible and damping piece.

[0013] The invention also relates to a slitter-winder which comprises at least one roll supporting the web reel. The slitter-winder according to the invention is mainly characterised by that said at least one roll supporting the web reel comprises a roll arrangement and a bearing system at both ends of said roll provided with fastening elements via which the bearing system and by that the roll are supported, and that the fastening elements of the bearing system of the roll are rigidly fastened in a mass body, and that said mass body is elastically and dampingly arranged into connection with a surrounding foundation.

[0014] Other additional features characteristic of the invention are illustrated in the accompanying claims.

[0015] In this specification, a roll also refers in addition to typical roll arrangements to e.g. a winding shaft of an unwinder from which the wound web is unwound on the unwinder.

[0016] The arrangement according to the invention can very effectively act on the vibration behaviour of the roll. In the roll arrangement according to the invention, resonance is concentrated substantially on two different natural frequencies. By choosing the mass body and elasticity suitably, the lower of these frequencies is obtained very low, whereby it is exceeded in a very early stage of winding. Then, excitation forces are still very small, whereby vibration remains low despite the exceeding of resonance. Furthermore, the upper natural frequency is higher in the arrangement according to the invention than in a roll arrangement according to prior art. Then when applying the invention to a slitter-winder, the susceptibility to resonance decreases.

[0017] The invention and its operation will now be described with reference to the accompanying schematic figures in which

Fig. 1 shows a roll arrangement according to an embodiment of the invention,

Fig. 2 shows a slitter-winder which is provided with the roll arrangement according to the invention,

Fig. 3 shows a roll arrangement according to an embodiment of the invention, and Fig. 4 further shows a roll arrangement according to another embodiment of the invention.

[0018] Fig. 1 shows a roll arrangement 50 according to an embodiment of the invention. It comprises at least one roll 51 and a bearing system 100 at both ends of the roll 51. In a bearing housing, there are fastening lugs or equivalents 115 via which the bearing housing is rigidly fastened in a base plate 120 of the bearing housing e.g. by means of bolts or threaded bars. Via the above fastening elements, the bearing system 100 and by that the roll 51 are directly and rigidly fastened in a mass body 125 which is elastically and dampingly arranged into connection with a surrounding foundation 30. The rigid fastening between the base plate 120 and the mass body means in practice that the bearing housing 110, the base plate 120 and the mass body 125 cannot substantially move in relation to each other. [0019] The mass body is arranged in the foundation 30 such that it substantially supports all its sides on the foundation. Advantageously, the mass body 125 is separated of the foundation 30 with corresponding surfaces such that vertical corresponding surfaces 130 are parallel in a direction perpendicular in relation to the longitudinal direction of the roll 51 and the machine direction (in the figure, from top to bottom). All substantially vertical corresponding surfaces 130 of the mass body 125 are against the equivalent corresponding surface of the foundation. This allows the vibratory motion of the mass body 125 in said direction and simultaneously the mass body is supported in a secure way on the foundation substantially limited by it in other directions. In this embodiment, the elasticity of the vertical corresponding surfaces is insignificant.

[0020] Between an opposite surface in relation to the fastening surface of the roll of the mass body 125, i.e. a lower surface 135, and the foundation 30 is fitted an elastic element 140. The elastic element 140 is advantageously a viscoelastic part with a certain spring constant and damping constant. Advantageously, the spring constant between the mass body and the foundation k = (2 -π - x)² - m where m is mass of the mass body and 1 <x<200. The elastic element 140 is arranged between the mass body and the foundation within the whole area of their common cross-sectional area.

[0021] The mass of the mass body 125 is considerable in relation to the combined mass of the roll 51 or rolls, if there are several (Fig. 2), supported on it, i.e. at least 10% of the combined mass of the supported rolls 51 , 52 (Fig. 2). Advantageously at both ends of the rolls, there are mass bodys substantially identical of their mass, shape and also of the way in which they are supported on the foundation. The mass of the mass body at the same end of the roll or rolls supported on the mass body is advantageously at least 10% of the combined mass of the roll or rolls.

[0022] The shape of the mass body 125 is advantageously a rectangular prism. In the longitudinal direction of the roll, the dimension of the mass body is at least the size of the base plate 120 of the roll or rolls supported on it. Otherwise, the size is dimensioned in accordance with each embodiment. When in use, dynamic load and/or vibration applied to the roll 51 convey as such directly to the mass body 125, whereby it is able to operate effectively in damping vibration. The mass body 125 this way increases the dynamic rigidity of the roll 51 directly and thus effectively acts on the damping of its vibration or the creation of vibration. Particularly when the roll is a roll participating in the forming of the fibrous-web reel in processing the fibrous web, it is also possible to cater for the effects of the dynamic load of the fibrous-web reel with the mass body 125.

[0023] Fig. 2 shows a slitter-winder 10 of a fibrous web. The slitter-winder comprises an unwinding station 15 of a machine reel on which the so- called machine reel can be unwound. During unwinding, the machine reel 20 is supported on a frame structure 25 of the unwinding station 15 which is arranged on top of a construction foundation 30. The slitter- winder 10 also comprises a slitting section 35 on which the full-width web W can be slit into partial webs W in a way known as such. The partial webs are wound into so-called customer reels 45 in the embodiment of Fig. 2 on a carrier-roll winder 40 of the slitter-winder 10 which comprises a roll arrangement 50 according to the invention. [0024] Carrier rolls 51 , 52 of the roll arrangement 50 in the slitter-winder are arranged to support the customer reels 45 successive in its cross- direction. In this embodiment, the so-called front roll 51 consists of one conventional roll, but the rear roll 52 comprises a unit consisting of two rolls 52.1 , 52.2 and endless belt loops 52.3 arranged to circle them. Above the customer reels, i.e. almost on the opposite side of the carrier rolls in the carrier-roll winder 40, there is a movably supported rider-roll beam 55. In the rider-roll beam is arranged a rider roll 60 such that it can press the customer reels with a desired force substantially from above them.

[0025] The carrier rolls 51 , 52 comprise a bearing system 100 which is here visible only at one end of the rolls. The bearing system comprises a bearing housing 110 and in its connection fastening lugs 115 via which the bearing housing is rigidly fastened in a base plate 120 of the bearing housing. The way of fastening has not been described here, but it advantageously occurs with a bolt joint or equivalent. These constitute in this embodiment the fastening elements via which the bearing system 100 and by that the rolls 51 , 52 are supported.

[0026] The base plate 120 is rigidly fastened in a mass body 125 which is elastically and dampingly arranged into connection with the surrounding foundation 30. The rigid fastening between the base plate 120 and the mass body means in practice that the bearing housing 110, the base plate 120 and the mass body 125 cannot substantially move in relation to each other, whereby the mass body is arranged to vibrate in the same phase and on the same amplitude with the bearing housing 110 of the carrier roll 51 , 52 and substantially also the carrier roll 51 , 52. [0027] The mass body is arranged in the foundation 30 of the slitter- winder such that it substantially supports all its sides on the foundation. Advantageously, the mass body 125 is separated of the foundation 30 with corresponding surfaces such that vertical corresponding surfaces 130 are parallel in a direction perpendicular in relation to the longitudinal direction of the roll 51 and the machine direction (in the figure, from top to bottom). All substantially vertical corresponding surfaces 130 of the mass body 125 are against the equivalent corresponding surface of the foundation. This allows the vibratory motion of the mass body 125 in said direction and simultaneously the mass body is supported in a secure way on the foundation substantially limited by it in other directions.

[0028] Fig. 3 shows a roll arrangement 50 according to another embodiment of the invention. In this embodiment, both the so-called front roll 51 and the rear roll 52 consist of one conventional roll. The arrangement is otherwise mainly equivalent to the roll arrangement shown in Fig. 1.

[0029] Fig. 4 shows a roll arrangement 50 according to another embodiment of the invention. Its structure is mainly equivalent to the arrangement shown in Fig. 1. Here however, the mass body 125 is of different material than the foundation 30. Furthermore differing from Fig.

1 , in addition to the lower surface also the vertical surfaces of the fastening surfaces between the mass body and the foundation are provided with elastic elements 140'. Then, the properties, such as elasticity, of the elastic element 140 between the lower surface of the mass body and the foundation can be chosen different from the properties of the elastic elements 140' of the side surfaces of the mass body. This way, vibration damping is obtained particularly effective. Instead of or in addition to the actual support surfaces, vertical guide structures can be used between the mass body and the foundation 30. The roll shown in Fig. 4 is a roll in connection with an unwinder, advantageously a winding shaft of an unwinder.

[0030] It should be noted that only a few of the most advantageous embodiments of the invention were described above. Thus, it is evident that the invention is not limited to the above embodiments, but it can be applied in many ways within the scope defined by the enclosed claims. It is also possible that features described in connection with different embodiments are used within the scope of the basic idea of the invention in connection with other embodiments and/or combine various units of the described features, if so required and technical possibilities for this existing.

Claims

1. A roll arrangement (50) of a fibrous-web machine for damping vibrations of a roll, which comprises at least one roll (51 , 52) and a bearing system (100) at both ends of said roll provided with fastening elements (115) via which the bearing system and by that the roll are supported, characterised in that the fastening elements (115) of the roll bearing system are rigidly fastened in a mass body (125) and that said mass body is elastically and dampingly arranged into connection with a surrounding foundation (30).

2. A roll arrangement of a fibrous-web machine according to claim 1 , characterised in that the mass body (125) is arranged into connection with the foundation (30) such that between the mass body and the foundation is fitted an elastic element (140, 140').

3. A roll arrangement of a fibrous-web machine according to claim 2, characterised in that between an opposite surface (135) in relation to the fastening surface of the roll of the mass body (125) and the foundation (30) is fitted an elastic element (140).

4. A roll arrangement of a fibrous-web machine according to claim 2, characterised in that the fastening surface between the mass body and the foundation comprises an elastic element (140, 140') provided with different properties in its different sections.

5. A roll arrangement of a fibrous-web machine according to claim 2 or 3, characterised in that the elastic element (140, 140') is a viscoelastic flexible and damping piece.

6. A slitter-winder (10), which comprises at least one roll (51 , 52) supporting a web reel (45), characterised in that said at least one roll (51 ) supporting the web reel comprises a roll arrangement (50) of a fibrous-web machine according to any one of previous claims 1-4.

7. A slitter-winder according to claim 6, characterised in that the slitter-winder comprises a carrier-roll winder and that the roll is a carrier roll (51 , 52) of a carrier-roll winder.

8. A slitter-winder according to any one of previous claims 6-7, characterised in that the roll is a roll of an unwinder of a slitter-winder.