EP0860545B1 - Apparatus to guide a web - Google Patents

Description

The invention relates to a device for guiding a material web, in particular paper or cardboard web, within a machine, especially one Paper or coating machine, with at least one a coat and two bearing journals Covering drum, the jacket of which a Has number of through openings.

Devices of the type mentioned here are known. They include a drilled or punched also referred to as a drum, over which at a start-up of the machine or in the event of a demolition the material web also as a threading strip designated narrow strip of material and while the normal operation of the machine Material web is guided. The roller is over one Drilled hole in the bearing journal of its cover connected to a suction device that the interior a vacuum is applied to the roller. The negative pressure is over the the coat openings penetrating the roller onto the outer surface of the coat transferred. By this measure become a flutter and a restless run of the material web avoided. Particularly disadvantageous with the known devices is that with increasing machine speeds the vortex losses of the Air flow in the interior of the roller and the friction losses so big in the trunnion bore be that adequate ventilation of the interior the roller is no longer possible. For remedy To create the cross section of the in the journal arranged hole can be enlarged. This is however not arbitrarily possible, so that the above described device for high machine speeds is no longer usable.

Devices are also known in which an air passage openings in the jacket Roller on its outer surface by means of a suction box of the jacket is sucked, creating a vacuum is introduced into the interior. The negative pressure spreads through the air vents up to the area covered by the material web the roller. Because of the high space requirement such devices, which within the Machine is not available in all cases their possible uses are restricted.

Furthermore, the German utility model G 91 06 451 U1 discloses a hollow Perforated jacket roller to create zones of different pressure for the formation of suction and pressure zones at least on the radially outer Jacket circumference. The hollow roller is with the longitudinal axis of the roller parallel, vane-like guide walls provided at least two zones each having the same width in the longitudinal axis of the roller, especially suction and pressure zones, which are only radial Differentiate direction (circumferential direction) with regard to their pressure.

It is therefore an object of the invention to provide a device to create that simple and compact structure and is a calm and flutter-free management the web even at high machine speeds guaranteed.

To solve this problem, a device proposed that mentioned in claim 1 Features. The device includes a drilled one Drum, one coat and two the coat has front-closing lid and is also referred to as a carrying drum. The coat has a number of through openings, through which a negative pressure from inside the drum the outer surface of the drum shell applied respectively can be transferred. The device is characterized by at least one inside the drum, arranged impeller, which divides the interior of the drum - seen in the longitudinal direction of the drum into separate chambers. With the help of the impeller, the inside of the drum is under vacuum and / or an excess pressure can be applied. The Generation of negative or positive pressure directly inside the drum shortened in advantageous Way of air flow and is independent from the vortex losses, so that at flow losses occurring during the suction of the drum can be reduced. hereby becomes the energy efficiency of the device improved for guiding a material web. The device builds very compact, so the space requirement the machine within which the device is arranged is can be reduced. Furthermore allows such an attached impeller in the interior of the drum another Improve the efficiency of suction, which a reduction in the operating costs of the machine is feasible.

An embodiment of the is particularly preferred Device, which is characterized in that the Impeller non-rotatably connected to a drive shaft is arranged concentrically to the axis of rotation of the drum is. Thus, the impeller can be the inside of the Drum - viewed in the longitudinal direction of the drum subdivide that the drum is only partially is vacuumed, that is, the interior and the Outside area only with a partial vacuum be charged. Preferably the outer ones Dimensions of the impeller to the interior of the drum adjusted so that undesirable backflow the air conveyed by the impeller its pressure side on the suction side of the impeller is prevented or at least kept very small. In this embodiment of the device, the

It also becomes an embodiment of the device preferred, which is characterized in that the impeller can be driven from the outside by means of the drive shaft is. For example, there is a on the shaft gear connected to a drive device or a pulley connected to a belt drive arranged that the drive shaft with a Drive torque applied.

An embodiment of the device is also preferred, where the impeller is driven by an electric motor is drivable, which is arranged inside the drum is. This measure makes the required Installation space for the device is further reduced. Added to that is that by the immediate Arrangement of the electric motor in the area of the impeller, due to a shortened powertrain that Cost of the device for guiding a material web can be reduced.

Furthermore, an embodiment of the device preferred, which is characterized in that the impeller in the front edge area of the drum arranged and the suction side of the impeller immediately adjacent edge area is facing. By vacuuming the edge area, a narrow strip of material, a so-called threading strip, when the machine starts up or passed through the machine after a web break is securely fixed and over the Drum.

Further advantageous embodiments of the device result from the other subclaims.

Figur 1

einen Ausschnitt einer Ausführungsform der erfindungsgemäßen Vorrichtung in Seitenansicht und

Figuren 2 bis 4

eine Ansicht weiterer Ausführungsvarianten der erfindungsgemäßen Vorrichtung in Schnittdarstellung.

The invention is explained in more detail below with reference to the drawing. Show it:

Figure 1

a section of an embodiment of the device according to the invention in side view and

Figures 2 to 4

a view of further embodiments of the device according to the invention in a sectional view.

The device described below is general inside a machine for guiding one Material web can be used. The following is purely exemplary assumed that the device inside a machine for producing a paper web, so inside a paper making machine, is arranged and for guiding a paper web serves.

Figure 1 shows a sectional partial view of the Device 1 according to the invention, one in the following designated as roller 3 includes the drum is hollow inside. The roller 3 has a jacket 5 and is at its front end areas each closed by a lid, of which only the cover 7 can be seen here. The coat 5 is provided with through openings 9 which the outer surface 11 of the jacket 5 with the interior 13 connect. The through openings 9 are as Drilled holes and point in the area of Outer surface 11 has an enlarged cross section.

The interior 13 of the roller 3 is of a circular cylindrical Through opening 15 is formed. The Cover 7 is arranged on the end face of the roller 3 and closes the interior from the environment from. The cover 7 is not shown Fasteners connected to the jacket 5. In this embodiment of the device 1 is the Cover 7 formed in one piece with a bearing pin 17, on which a bearing 19 is arranged. At the other end face of the roller, not shown 3, the second cover 8 is arranged, on which a additional bearing journal is arranged. The bearing journals serve to store the roller 3.

An impeller 21 is arranged inside the roller 3, the rotatably connected to a drive shaft 23 is. The drive shaft 23 is by means of Bearings 25 and 27 in a cover 7 and Bearing pin 17 penetrating bore 29 is mounted. The bore 29 is concentric with the dashed line indicated axis of rotation 31 of the roller 3. How 1 shows the drive shaft 23 one-sided, that is, overhung and pointing a drive pin 33. In the drive pin 33 is a groove 35 is arranged to receive a Key serves. About the drive pin 33 can a drive torque to the drive shaft 23 from one Transfer drive device, not shown become. The drive device can directly engage on the drive pin 33 or, for example with a gear or a pulley be connected to it.

The arranged on the drive shaft 23 and with this connected impeller 21 also has a wing designated blades, of which only here the blades 37 and 39 are visible. The impeller 21 is in the front edge area 41 of the roller 3 arranged. The impeller 21 has an outer diameter on that to the diameter of the through hole 15 is adjusted so that a narrower Gap 43 between the blades of the impeller 21 and the jacket 5 of the roller 3 is formed. The impeller 21 divides the interior 13 of the roller 3 into one another separate chambers 45 and 47. The first, smaller chamber 47 is the impeller 21 and the Cover 7 and the jacket 5 and the second, larger Chamber 45 of the impeller 21 and the second cover 8 or another impeller and the jacket 5 limited. The suction side of the in this embodiment is designed as an axial wheel impeller 21 here the chamber 47 and the pressure side of the impeller 21 facing the chamber 45.

The following is the operation of the impeller explained in more detail using the air flow.

When the impeller 21 is acted upon by a drive or torque, air is drawn into the chamber 47 from the outer surface 11 of the casing via the through openings 9 in the region of the edge region 41. The air flow is indicated by arrows 49. The air drawn in is conveyed by the impeller 21 from the chamber 47 into the chamber 45, where it can escape again through the through openings 9 arranged in this area in the jacket 5 of the roller 3. The following pressure conditions result during the suction of the roller 3: In the chamber 47 there is a negative pressure p ₁ which is greater than the negative pressure p ₀ prevailing in the edge region 41 under suction. Starting from the atmospheric pressure as a reference and considering absolute pressures, the pressure p ₁ is therefore less than the pressure p ₀ . In the chamber 45 there is an overpressure designated p ₂ .

Due to the negative pressure P ₀ acting in the edge area 41 on the outer surface 11 of the roller 3, a particularly narrow paper web / threading strip guided over the roller 3 can be sucked in and held in place. The threading strip can be passed over the roller 3 smoothly and without fluttering. Furthermore, the suction of the roller 3 reliably prevents the strip from being moved out sideways in the direction of the center or the lateral edge of the roller.

The device 1 is particularly characterized by a compact structure, the low Because of the air flow, the friction losses are very are low. The device 1 is also at high Machine speeds can be used, the Provision of a high vacuum at any time can be guaranteed. Elaborate and costly Pipelines through which the air known devices deployed from the roller will not be needed here.

Figure 2 shows a side view of another Embodiment of the device 1. Parts that with those in Figure 1 are the same Provide reference numerals so that in this respect on their Description in Figure 1 can be referenced. in the The following only deals with the differences.

An electric motor 51 is arranged inside the roller 3, with the motor shaft 53, the impeller 21st is rotatably connected. The electric motor 51 is included here only indicated fasteners 55, for example Screws attached to a holding flange 57. The holding flange 57 is in turn with further fastening means 55 on the cover 7 of the Roller 3 fixed. The energy supply for the electric motor 51 takes place via connecting lines 59 and 61, which are arranged in the bore 29 of the cover 7 are. The connecting lines 59 and 61 are with a Contact plate 63 connected or end in this, the bore 29 and thus the interior 13 completes from the environment. The Power supply is via an only indicated here Power supply device 65, which means the contact plate - not shown - sliding contacts with the connecting lines 59 and 61 is connected.

When the device 1 is started up or during operation, the impeller 21 arranged inside the rotating roller 3 can be driven by means of the electric motor. The impeller 21 sucks air from the outer surface 11 of the roller 3 through the through openings 9 into the interior 13 or into the chamber 47 via the through openings 9. The air flow is indicated by arrows 49. The air in the chamber 47 is conveyed by the impeller 21 into the second chamber 45 and can escape through the through openings 9 arranged in the region of the chamber 45 in the jacket 5 of the roller 3 to the outer surface of the jacket or to the environment. The impeller 21 sucks air in the edge region 41 on the outer surface 11 of the roller 3, so that a negative pressure designated p ₀ is established. The pressure ratios within the chambers 45 and 47 or the interior 13 correspond to the pressures described in FIG. 1. The negative pressure p ₁ acting in the chamber 47 is greater than the negative pressure p ₀ , and an excess pressure p ₂ acts in the chamber 45 which, as already described, can escape through the through openings 9. A comparison of the two pressures p ₁ and p ₀ , considered absolute values, shows that the pressure p _{1 is} less than the ambient pressure or atmospheric pressure and the pressure p ₀ .

The embodiment shown in Figure 2 Device 1 stands out due to the positioning the impeller drive inside the roller, due to a compact design. The device is also in particularly cramped installation conditions can be used inside the machine.

Figure 3 shows a third embodiment of the invention Device 1 in side view. The same parts have the same reference numerals provided so that in this respect to the description Figures 1 and 2 is referred. The in Figure 3 shown embodiment variant of the device 1 differs from that shown in FIG. 1 in that in both front edge areas 41 and 42 of the roller 3 each have an impeller 21 and 21 'arranged inside the roller 3 is. That arranged in the right edge area 42 Impeller 21 'is analogous to that described in FIG. 1 Impeller 21- with a drive shaft 23 rotatably connected in the cover 8 by means of bearing 25 and 27 is overhung. This is also here Impeller arranged concentrically to the axis of rotation 31 of the roller and divides another from their interior 13 Chamber 47 'from between the impeller 21' and the lid 8 is arranged. The suction side of the Impeller 21 'faces the cover 8, so that a suction of the outer surface 11 of the roller 3 in Edge area 42 possible during operation of the impeller 21 ' is. The interior 13 of the roller 3 is thus divided into a total of three separate chambers; in the in the end areas the roller arranged chambers 47 and 47 'and in that arranged between the impellers 21 and 21 ' Chamber 45.

If a drive torque is applied to the drive shafts 23 of the impellers 21 and 21 '(see arrows labeled M _A ), the edge regions 41 and 42 of the roller are vacuumed. In this case, a negative pressure p ₀ is established on the outer surface, which holds a paper web or a threading strip guided over the roller securely on the roller 3, so that it can be transferred flutter-free and smoothly. The use of the device 1 is expanded by the possibility of double-sided edge suction.

The wheels 21 and 21 'are - as described above - can be driven separately. This can each have an electric motor arranged inside the roller be assigned or their drive takes place from the outside, for example by means of a Belt drive.

Figure 4 shows a side view of a fourth embodiment the device 1. are the same parts provided with the same reference numerals so that to the description of Figures 1, 2 and 3 can be referred. In the interior 13 of the roller 3, near the edge regions 41 and 42 is one in each case Impeller arranged. The suction side of the impellers 21 and 21 'face the center of roller 3. in the Cover 7 are holes 67 and 69 and in cover 8 Bores 67 'and 69' are provided which provide a flow connection from the inside of the roller 3 to the outside enable. Their function is explained in the following the resulting during the operation of the impellers Air flow explained in more detail.

When the drive shafts 23 are acted upon by a drive torque, which is indicated here by the reference symbol M _A and an arrow, the impellers 21 and 21 ′ start air in the area of the chamber 45 through the through openings 9 arranged in this area in the jacket 5 of the roller 3 suction from the outer surface 11 and convey it into the chamber 47 or 47 '. An overpressure is formed in the chambers 47 and 47 ', which is provided here with the reference symbol P ₂ . The excess pressure can escape to the outside through the bores 67 and 69 or 67 'and 69'. A vacuum p ₀ , which is smaller than the vacuum p ₁ acting in the chamber 45, arises in the area of the suctioned outer surface 11 of the jacket 5.

By arranging two wheels and that Drilling holes in the cover of the roller is a suction of the entire outer surface of the Jacket 5 of the roller 3 possible. The one shown in Figure 4 Device 1 is thus both for Transfer of an entire web of material as well as one narrow threading strip can be used.

The impellers described with reference to Figures 1 to 4 21 and 21 'can be used both as axial gears also be designed as cross flow wheels. Especially advantageously results in their concentric Storage to the axis of rotation 31 of the roller 3 a subdivision of the interior in several chambers, so that a suction and / or blowing of a defined Realizable area of the outer surface of the roller is. The impellers are preferably fan wheels trained, that is, the pressure ratio between its pressure side and suction side preferably less than 1.3. It is also possible, form the impellers as compressor wheels with which a larger pressure ratio and thus a higher negative pressure / positive pressure can be generated.

The device 1 according to the invention can for example inside a paper machine instead of one known carrier drum roller can be used. On Carrier drum roller is at the end of the paper machine arranged and consists of a roller, the so-called Carrier drum against which the drum or Winding mandrel is pressed onto which finished paper web is to be wound up. The Paper web is passed over the carrier drum by a Nip guided between the drum and drum and then wound up on the reel. The one at the beginning the winding process by means of a transfer device Threading strips transferred to the through the device 1 replaced the carrying drum. The applied from the inside to the outer surface of the roller Vacuum holds the stripe on the coat the roller so that it does not extend over the edge out of the roller or toward the center of the roller running. This ensures a safe transfer of the threading strip even at high machine speeds possible.

In summary, it should be noted that the device 1 can be built simply and compactly and less because of the simple construction Has costs than known devices. It is possible, an embodiment explained with reference to Figure 4 the device 1 within the dry or To use the press section of the paper machine, for example, instead of one of the overpass Dryer screen and a suction roll serving a material web. It is clear that the invention Device can be used wherever a Material web, a narrow material web strip or plate-shaped goods deflected by a roller become and need a guide.

Claims (10)

1. Device (1) for guiding a material web, in particular paper or board web, within a machine, in particular a papermaking or coating machine, having at least one drum (3) comprising a jacket (5) and two covers (7, 8) provided with bearing journals (17), whose jacket (5) has a number of passage openings (9), and having at least one impeller (21; 21') arranged in the interior of the drum (3) characterized in that the at least one impeller (21; 21') subdivides the interior (13) of the drum (3) - as viewed in the longitudinal direction - into chambers (45, 47; 47') which are separated from one another and are at different pressures.
2. Device (1) according to Claim 1, characterized in that the impeller (21; 21') is connected in a rotationally fixed manner to a drive shaft (23) that is arranged concentric with the axis of rotation (31) of the drum (3).
3. Device (1) according to Claim 1 or 2, characterized in that the impeller (21; 21') is mounted in a floating manner in a cover (7, 8) of the drum (3).
4. Device (1) according to one or more of the preceding claims, characterized in that the impeller (21; 21') can be driven from the outside by means of the drive shaft (23).
5. Device (1) according to one or more of Claims 1 to 3, characterized in that the impeller (21; 21') can be driven by an electric motor (51) that is arranged in the interior of the drum (3).
6. Device (1) according to one or more of the preceding claims, characterized in that the impeller (21; 21') is arranged in the end edge region (41, 42) of the drum (3).
7. Device (1) according to Claim 6, characterized in that the suction side of the impeller (21; 21') faces the directly adjacent edge region (41; 42) of the drum (3).
8. Device (1) according to one of Claims 1 to 6, characterized in that the pressure side of the impeller (21; 21') faces the directly adjacent edge region (41; 42) of the drum (3).
9. Device (1) according to one or more of the preceding claims, characterized in that an impeller (21, 21') is arranged in each of the two end edge regions (41, 42) of the drum (3).
10. Device (1) according to one or more of the preceding claims, characterized in that the impeller (21; 21') is constructed as an axial impeller or transverse-flow impeller.

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