FI118056B - Arrangement for damping the vibrations of a deflection compensated roll - Google Patents

Description

1 118056 Arrangement for damping of vibration compensated roll

The invention relates to an arrangement for damping the vibrations of a deflection compensated roll of a paper / board machine or a post-processing machine, which roll includes a roll sleeve which is rotatable about a stationary roll axis and which is supported by a the loading elements include a shoe part substantially radially movable against the inner surface of the roll and a piston part radially supported against the shaft 10, the shoe part and the piston part being arranged substantially parallel to the main load, and the shoe part and the piston part having the transmitted vibrations are led to pass between the shoe part and the piston part.

15

Deflection-compensated roll rolls of a paper / board machine or a post-processing machine are conventionally supported on the stationary roll axis by hydrostatic loading elements which act radially on the roll shell. The load elements may be used both as bearing elements 20 between the roll shell and the shaft and as support elements to compensate for deformations of the roll shell, for example at the roll nip. These load elements are measured against the inner surface of the roll shell generally by hydraulic pressure medium.

• * ·: One problem with this type of construction is that the vibrations from, for example, the nip formed by the roller and the counter roller ♦ are transmitted fairly smoothly through the load element • ·: 25 to the roll shaft and further to the frame. The loading element is generally a loading shoe provided with a lubricating oil chamber opening * * * against the inner surface of the roll for a lubricant film between the inner surface of the roll and the loading shoe. This lubricant film and the hydraulic medium 30 flowing in the flow channels in the flow channels in addition to the loading medium for the hydraulic medium already dampen the transmission of vibration to the shaft. The loading shoe, on the other hand, is supported on the shaft structure of the roll either directly or via pressure medium.

, ·· *. Thus, only a space for a pressure medium is provided between the load shoe and the shaft, which transmits forces between the shoe and the shaft. • «* '· * · [vibrations transmitted from the clamp to the load shoe allow for a fairly smooth passage directly to the shaft and further • · 2 118056 to the frame structure. Especially in many felt-based and coating-based oscillations, damping is insufficient.

Accordingly, it is an important object of the present invention to provide an arrangement whereby the support of a roll compensated roll roll shell arranged to rotate about a stationary axis can be arranged such that vibrations transmitted from the nip cannot pass through the loading elements to the roll shaft.

The arrangement of the present invention is characterized by what is set forth in the characterizing part of independent claim 1.

Preferred embodiments of the invention are set forth in the dependent claims.

The arrangement according to the invention achieves numerous advantages over the prior art solutions. The arrangement functions both as a transmission means for transmitting the load forces flexibly from the loading element to the roll shaft, and as a damping device which absorbs from the vibration of the nip. The arrangement substantially dampens the conduction of oscillations between the load element and the shaft of the roll and further on the run-20 superstructures. On the other hand, due to the arrangement, the load force variations are not transmitted directly from the nip to the shaft but with a small delay. The sharpest load peaks level off and thus reduce the stress on the roller structures.

An additional advantage is also that, because the loading element is arranged in the radial direction of movement * 25 in relation to the axis of the roll, particularly in the event of failure - · 9 "V, for example when pressure in the fluid medium drops rapidly. and more against it. This reduces, for example, the risk of · trapping between the inner surface of the roller and the sliding surfaces of the load shoe.

In the following, the invention will be described in more detail with reference to the accompanying drawings in which: * * * FIG. 1 schematically illustrates a deflection compensated roll according to the prior art, FIG. 2 shows a bearing arrangement according to the invention in cross sectional direction, Figure 3 illustrates an embodiment of Figure 2 in a situation where the loading force of the nip in the radial direction of the roll has increased with respect to the situation of Figure 1; Figure 4 further illustrates a system advantageously used in connection with the invention. a arrangement in which the shoe part and the piston part are both provided with spring means and a pressure chamber formed for the pressure medium, Fig. 5 further illustrates another arrangement, preferably used in connection with the invention, in which For medium in connection with the piston part Rea jestettyyn volume of the gas bag, which is attenuated by means of pressure medium via the pressure pulses due to the oscillations, and; Fig. 6 further shows another arrangement, preferably used in connection with the invention, in which active members are disposed between the shoe part and the piston part.

♦ · »• * * • · ♦ *

Fig. 1 schematically illustrates an arrangement 1 according to the prior art, in which: a roll 2 is arranged to rotate about 25 stationary massive shafts 6. 6 by means of hydrostatic loading elements 10a acting on the inner surface of the roll shell 2. The load elements 10a are traced on the axis 6; * 4> in a plane parallel to the main load F. There are load elements 10a. ***. 30 axial lengths of n rolls, n = 1-100 depending on roll length and position, * · · *. typically 20-80. In the axial direction, the loading elements 10a may be guided ... "individually or in groups of a few, for example 2 to 6 elements.

• · • · M »

The supply of hydrostatic pressure medium to the pressure space 19 between the loading element 10a and the shaft 6 is known in the prior art. The load F caused by the counter roll 9 to the roll shell 118056 tends to move the roll shell 2a as well as the loading element 10a relative to the shaft 6. In the illustrated arrangement, the hydraulic pressure medium provided in connection with the element 10a is supplied through the supply channels 101 and 8 formed in the shaft 6 to the cavity 19. The pressure in the cavity 19 is always adjusted so that the in a substantially parallel direction. The problem with such an arrangement is that the vibrations transmitted from the pin N to the loading member 10a can be carried almost directly to the shaft 6 and further to the frame structures (not shown).

10

Figure 2 illustrates an arrangement according to the invention for damping nipple vibrations, wherein the damping is effected by rubber elements acting as both load springs and vibration dampers. Pääkuorma the direction of the arrow F caused by the nip, therefore, tends to cause deformation of the jacket 2a of the roll 15 in the radial direction. To compensate for the effects of the main load F, the stationary shaft 6 is now provided with loading elements 7 by means of which a force opposite to the main load F is applied to the inner surface of the roll.

The arrangement includes a separate piston portion 10 and a separate shoe portion 5 further arranged in connection with the piston portion 10, the sliding surface 5a of the shoe portion facing the inner surface of the sheath 2a. On the sliding surface 5a of the load shoe, lubricating oil chambers 4 are formed at the nip which open against the inner surface of the roll shell 2a. The chambers 4 are fed with: 1 · 1: high-pressure hydraulic medium through channels 3. Thereby a lubricating oil film is provided between said opposing surfaces ··· and at the same time eliminates • · · 1; 1 · 25 substantially radial deformations of the roll by the main load F 118056

The arrangement according to the invention comprises, in accordance with the invention, damping members 17, 18. The members are mated by means of fastening members 14-16 attached to the shoe part 5 and the piston part 10 between the shoe part 5 and the piston part 10. Now, both the nip load-5 force and the vibrations coming from the nip are transmitted from the shoe part 5 to the piston part 10 via damping elements 17, 18. The force exerted by the piston portion 10 to compensate for the nip main load F is thus at least substantially transmitted through the elements 14-18 to the shoe portion 5.

10 The damping elements 17, 18 are arranged between the shoe part 5 and the piston part 10 so that the vibrations are specifically transmitted by the shearing forces of the damping members. The damping elements are preferably formed of an elastic material, for example rubber or the like. Thus, the vibrations transmitted from the shoe part 5 are effectively suppressed in these members. The damping properties of the rubber elements at par-15 are at their peak when the forces are transmitted through shear forces.

In the arrangement of Figure 2, the fastening members are formed of metal rings 14, 15, 16 mounted between the load shoe 5 and the piston member 10, and the members 14, 15, 16 can be formed, for example, of metal sleeves or rings. The sleeves are secured at one end 20, for example, by welding to either the shoe part 5 or the piston part 10 respectively. The damping elements 17, 18 arranged between the fastening members 14, 15, 16 can be made of rubber or similar elastic damping material. The attachment to the members 14, 15, 16 may be performed by, for example, vulcanization or gluing.

• · · · _. . 25 • · · 'The vibration damping property of the structure also has an oil supply to the crank "··. Elastic hoses 13. This is because the portion where the loading shoe * * 5 moves downward and the piston portion 10 remains stationary causes no pressure peak, i.e. the volume does not decrease.

It is particularly advantageous to adjust the arrangement according to the invention so that it progressively dampens the vibration as the load force increases. The damping elements 17, 18 are arranged relative to each other such that, depending on the magnitude of the loading force coming from the nip, said force is further transmitted to the piston portion 10 · '· *. 35 through one or more damping elements. Thus, the damping elements 17, 18 are preferably arranged so that, when the loading forces transmitted from the nip are small, only a portion of the damping elements transmit the loading forces from the fastening element 14 of the shoe section 5 to the fastening element 16 of the piston section.

In the situation of Fig. 2, the main load F is small and hence the pressure in the loading chamber 19 between the piston part 10 and the shaft 6 is low. The counter force required to compensate for the load force is transmitted through the load shoe 5 exclusively through the thinner damping element 17. In this situation, the stiffness of the thinner element is suitable for damping. Through the thicker element 18 there is no contact with the underside of the load-bearing shoe 5.

Fig. 3 shows a situation in which the main load F has increased relative to the situation in Fig. 2. At the same time, the pressure in the chamber 19 is correspondingly increased to provide a corresponding compensating counter-force on the piston member 10. The metal sleeve 15 15 has now come into contact with the shoe part 5 by pressing into contact with its lower surface. The main load F, and also the vibrations, are transmitted between the load shoe 5 and the piston part 10 through a thicker damping element 18 now. The thinner element is resilient due to the greater need for power transmission so that the metal sleeve 15 of the thicker element 18 engages the lower surface 20 of the loading shoe 5. In this situation, the stiffness of the thicker element is suitable for damping. According to the same principle, only one, | \ #> three or more elements can be used. The elements according to the invention are preferably arranged such that, as the main load F increases, the stiffer and larger damping elements always transmit power and at the same time participate in the damping of vibrations. 25 fungus.

Further, it is contemplated that sleeve portions 14-16 will be provided with additional damping pieces, e.g., rubber parts at the edges such that contact with the underside of the shoe portion 5 occurs via the aforementioned additional damping portion, • ·· 30 nos.

• · • 1 • ♦ ·.

Fig. 4 further shows an arrangement which can be considered advantageous in connection with the solution according to the invention. Here, the damping elements 17, 18 are not shown: ·: ···. A pressure chamber 37 disposed between the shoe part 5 and the piston part 10 is pressure-1 · '. For the lubricant 35, spring means 35 disposed in said chamber and supported on both the shoe part 5 and the piston part 10 118056 serve to provide a substantial part of the loading force between the load shoe 5 and the piston part 10. The spring means 35 may be, for example, flat springs, disc springs or the like.

The pressure medium flow connections 31 are arranged to lead from the chamber 4 to the aforementioned chamber 37 by means of a throttling flow connection. The flow connection to the chamber 37 is formed through the flow body 32. The flow body is arranged to extend substantially in the direction of the main load F and is fitted to the recesses 38 and 39 formed in the shoe section 5 and the piston section 10, from which the flow channels 10, 30 continue to flow into chambers 4 and 19 for pressure medium. Preferably, sealing members 11 and 12 are provided in connection with the volumes formed for the pressure medium.

The pressure medium flowing into the chamber 4 is arranged to flow through the flow channel 34 formed through the flow piece 32 15. Further, at least one throttle flow channel 36 is provided from the flow channel 34 in the pressure chamber 37 for the pressure medium 37. The vibrations transmitted from the pin part to the shoe part tend to change the volume of the chamber 37. The rate of change of volume is controlled by the throttles 33 and 36. Thus, in practice, the damping of vibrations is enhanced by the flow resistance occurring in the flow channels 20.

: *. Further, Fig. 5 shows another additional arrangement preferably used in connection with the invention according to the invention. Again, there is not shown a damping element 17, 18. Here, a gas tight or ava ** ** V vis vis ainakin tai ** ** ** V V ainakin or a flexible gas bag filled with a gaseous, preferably pressurized, material is provided in connection with the piston part 10. , the container having an elastically compressible volume 41. The gas * ['.I ·' 's bag is disposed in a substantially closed volume 42 * · provided for it so that it substantially fills this volume and the gas bag unfilled .. the volume is filled with pressure medium. The walls of said volume are further provided with choke flow openings 43 through which the pressure medium can flow between other pressure medium chambers 19, 4. The gas bag is pressurized with gas so that the pressure strokes transmitted from the chamber 19 due to the vibrations of the shoe portion 5 are * * * partially led through the throttle flow openings 43 to the volume of the chamber 42. Through the throttle openings, the flow of pressure medium caused by the pressure strokes is resisted and thus also damped by vibration. By using suitable pre-pressure in the gas bag 41, a suitable degree of vibration damping is achieved.

According to a further aspect of the invention, the shoe part may further be provided 5 extending into the chamber 19 of the piston member 10 with a substantially rigid projection 51 extending substantially in the shape of the end of the chamber 19 as shown in Figures 2 and 3. As the shoe part 5 moves 5 anti-movement force, whereby the projection 51 contributes to damping the vibrations 10 transmitted from the nip to the shoe part.

Fig. 6 shows a further arrangement of faders, which may also be considered advantageous in connection with the arrangement according to the invention, in which the damping elements 115 between the shoe part 10 and the piston part 5 are formed of active members 15. The members may be formed, for example, from a magnetostrictive or electro-friction material or a piezoelectric crystal or a combination thereof. The means are controllable from the outside of the roll by means of a suitable control signal. The length of the members in the radial direction of the roll axis 6 is preferably adjusted in the opposite phase to the oscillation transmitted from the nip, whereby the oscillation is substantially damped. The oscillation, and in particular the main oscillation therein, can be determined in advance for adjustment. This adjusts the frequency at which the length of the active substances is altered, as well as the amplitude of the oscillation corresponding to the travel distance · 1 · 1; the length of said organs is altered in the opposite phase to the vibration.

* • · · ·: 25 • 1 · * 1 · 1

The invention has been described above with a combination of deflection compensated roll loading elements • 1 «1 .1 ··. teydessä. However, it can also be applied to plain bearing roller bearing elements, either as such or with minor modifications.

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Claims (16)

1. Arrangement for damping a bending-compensated roller (2) vibration of a paper / board machine or finishing machine, said roller having a rotatably mounted roller shaft (2a) rotatably supported by said roller shaft (9a) against said roller shaft (9). the stationary roller shaft (6) with load element (7), white load element (7) can be loaded against the inner surface of the roller sheath (2a) with hydraulic pressure media, which load element (7) comprises a shoe element (which is substantially radially movable) ( 5) and a radially movable piston portion (10) abutting the shaft (6), the shoe portion (5) and piston portion (10) arranged movable substantially parallel to the direction of the main load (F), and between the shoe portion (5) and the plunger member (10) has been provided means through which the vibrations mediated from the nip are arranged to be guided between the shoe member (5) and the plunger member (10), characterized in that said member exhibits at least one damping means. element 15 (17, 18) formed of elastic material and the damping elements (17, 18) are arranged so that said vibrations are mediated by cutting forces present in the element, said vibrations being substantially damped during passage of the element. . 2. Arrangement according to claim 1, characterized in that the shoe part (5) and the piston part (10) are arranged to move relative to each other substantially in the direction of the main load (F) and that said at least one damping element (17, 18) is arranged. between the shoe part (5) and the piston part (10) so that they are formed from the nip. the vibrations as the load derived from the nip are transmitted to substantially: part via said damping element. • * · • · · · · · · Arrangement according to claim 1 or 2, characterized in that the damping elements (17, 18) are more than one, and that the damping elements are arranged between themselves so that the force in the direction of the main load (F) is conveyed depending on the - • ··. The size of the fluid load (F) via one or more damping elements (17, 18). • * * · ·. • · 4. Arrangement according to any of claims 1 to 3, characterized in that between the piston part (10) and the shoe part (5), a pressure chamber (37) is formed for the pressure medium, where the shoe part (10) is loaded against the roller sheath. (2a) inner surface using i. · * ·. The chamber maintains pressure. * * * 13 1 1 8056 5. Arrangement according to claim 4, characterized in that a flow connection for the printing medium is arranged between the piston part (10) and the shoe part (5). Arrangement according to claim 5, characterized in that throttling is arranged in said flow connection between the shoe part (5) and the piston part (10) so that the vibrations transmitted from the nip are damped as the pressure medium flows through said throttle. Arrangement according to claim 5, characterized in that between the shoe part 10 (5) and the piston part (10) there is provided spring means (35), which convey a substantial part of the main load (F) between the shoe part (5) and the piston part (10). ) well. Arrangement according to claim 7, characterized in that said spring means (35) are arranged in the pressure chamber (37) between the shoe part (5) and the piston part (10). 15 Arrangement according to any one of claims 3-8, characterized in that a flow piece (32) which extends substantially in the direction of the main load (F) and which piece (32) extends in the chamber (37) thereto bed to the shoe part (5) and the piston part (10), and in which a piece (32) is provided a flow connection (34) for the pressure medium between the shoe part (5) and the piston part (10), and in which a piece (32) is provided. throttle flow connection between the flow connection: ·. (34) and the chamber (37), whereby the flow medium of the printing medium caused by the pressure variations of the printing medium is throttled and thereby damped vibrations. • * * • · * * "·. 25 Arrangement according to any one of claims 1 to 8, characterized in that, in connection with the piston part (10), at least one pressure chamber (42) is arranged, in which at least one essential part with compressible material is filled with elastic material. · Container (41), and that the space (42) is filled with the portion of the pressure medium which has been left over from filling the elastic container (41), for which the pressure medium in * ... 30 at least one to the space ( 42) adjoining wall is provided with a throttle for the printing medium such that the printing medium can flow between the space (42) and the other rooms arranged for the printing medium. • · · * Arrangement according to claim 10, characterized in that the container (41) *. ·· *. 35 is arranged in said chamber (19) of the piston part (10). · * · '14 118056 Arrangement according to claim 1, characterized in that the shoe part (5) and the piston part (10) are arranged mutually and that in connection with the piston part (10), at least one pressure chamber (42) is arranged in which at least one essential element is arranged. parts with compressible material filled with elastic container (41), and that the space (42) is filled with the part of the printing medium left over from filling of the elastic container (41), for which printing medium in Stminstone one adjacent to the space (42) wall is provided with a throttle heel for the print medium so that the print medium can flow between the space (42) and the other spaces provided for the print medium. 10 Arrangement according to any one of claims 1 to 12, characterized in that from the shoe part (5) is arranged to extend to the chamber (19) of a piston part (10) a substantially rigid, in the end facing the chamber (19) as a substantially widespread shaped projection (51) such that as the shoe portion (5) moves in the direction of the main load (F), the projection (51) generates in its displacement in a corresponding manner in the pressure medium of the chamber (19) counteracting the movement of the shoe portion (5) force, the projection (51) attenuating the vibrations mediated to the shoe part (5) from the nip. Arrangement according to any of claims 1 to 13, characterized in that the means arranged between the piston part (10) and the shoe part (5) are arranged to function actively. ·· a · * ·· Arrangement according to Claim 14, characterized in that said means. length in the radial direction of the shaft (6) is counter-phase controlled relative to that of the nip (N). 25 mediated main vibration. Arrangement according to claim 14 or 15, characterized in that said • * means are made of magnetostrictive or electrostrictive material or a piezoelectric crystal or a combination. of these aa • * · * * a • · * a * • a · aaa * · • aa! a *: * aaaa • aaaaaa * a aa * * aaa: .a ·· '