FI121016B - Actuator for drying cylinder of fiber web machine - Google Patents

Description

Actuator for drying cylinder of fiber web machine

The present invention relates to a drive mechanism for drying a fiber web machine, comprising: means for attaching the steam supply and / or condensate discharge pipe to the bearing housing of the cylinder.

By fiber machine, we mean a paper, board, tissue 15 or pulp drying machine.

From U.S. Patent No. 62575, a mechanical actuator for a drying machine group of a papermaking machine is known, comprising a plurality of gears that form a gear. The shaft driven by the drive motor rotates the first hammer gear, which in turn drives the second gear mounted on the cylinder shaft, either directly or via side gears. The gear wheels are fitted inside the housing on the side of the dryer section. In the same housing, both the gears of the gears and the shaft of the driven cylinder are mounted. Such a solution, in which the drive housing forms the body of the machine on which the cylinder and gears are mounted, is called the drive housing.

FI-98 984 discloses a cylinder group drive gear comprising a housing body for providing rotation drive from the outside of the gearbox through the shaft. The gear is rotated directly or indirectly by means of a gear wheel and two gear wheels which are engaged therewith to transfer the drive to both sides of the gearbox and further to the cylinders. The gearbox housing frame is supported 2 fixedly on the foundation, whereupon the load due to the weight of the gearbox is transferred to the foundation through the housing housing. The two cylinders are operated so that there is a floating connection between the cylinders shafts and the gearbox that allows certain angular changes to the cylinders shafts. In this way, torques caused by misalignment of the shafts are not transmitted from the cylinders to the gearbox or from the gearbox to the cylinders. The shafts of the cylinders are supported separately on the bearing brackets supported by the foundation.

From US Patent 115980 there is known a papermaking cylinder actuator comprising a housing body, bearings mounted on the housing body and its bearing cover for rotatably supporting the cylinder 10 blade from its shaft and a single or multi-stage gearbox mounted on the housing body. The main gear wheel which drives the shaft and is centrally positioned relative to it is rotatably mounted on the housing body. A tooth coupling is connected between the shaft and the main gear to eliminate the angular changes of the shaft with respect to the main gear. The tooth clutch comprises an outer tooth portion of the tooth clutch permanently mounted on the shaft 15. The main gear with the bearing hole is mounted on the bearing cover of the housing frame. Such a compact drive is called a DRG gear unit.

Today, the most common drives for the dryer section are the drive rollers and DRG gears described above, each of which combines means for supporting a cylinder or roll axis and means for rotating a cylinder or roll in the same housing body. One or two drying cylinders or rollers belonging to the same group can be used simultaneously with both known actuators. In the drive housing, the gear wheels and cylinder shafts are mounted on a bearing housing, which in turn is supported on the foundation. Applying Exposed Cases to Modern High-Speed Paper Machines is challenging because tooth contact does not remain straight. For high-speed machines, DRG gears have been developed as compact gear units. The DRG gear is coupled to the cylinder shaft with a special gearwheel coupling that enables high speeds while reducing noise and vibration levels. The biggest disadvantages of DRG-3 gears are their high price and the need for a separate frame support.

In addition to the enclosures and DRG-5 gears, pivot gears are used with the single-wire dryer roll swivel rolls. A shaft mounted gear unit is a gear mounted on the drive shaft of a driven roll and not mounted on a machine frame by bolts or the like. In pin gear, the end of the drive shaft is mounted in the bore of the secondary shaft of the gear, whereby the drive shaft bears the weight of the entire gear and receives other external forces acting on the gear except the torque which tends to rotate the gear. This latter force is absorbed by the torque support, which forms a fixed anchor or anchor point for the gear unit.

In the known suction roll drive actuator applications, the pin gear and bearing housing 15 are fixedly connected from their housings, which requires the use of load-bearing seals due to shaft deflections, which require periodic maintenance and replacement.

In prior art solutions, the pin gear is generally positioned at the end of the roll shaft so that the frame supporting the roll is between the drive gear and the roll. Such a solution is not, as such, suitable for at least cylinders with two-way condensate drainage with a standing siphon.

The steam used to heat the surface of the cylinder is fed into the cylinder via a steam supply tube and the condensate formed as the steam condenses is removed from the cylinder via a condensate discharge tube. Standing siphon tubes need support from outside the cylinder. The connections of the steam supply and condensate drainage pipes to the cylinder must be sufficiently rigid to avoid any significant risk of vibration. For the same reason, the unsupported length of the steam supply and condensate drainage pipes should be kept as short as possible. Attaching the steam supply and condensate drain pipes to tap-30 is not recommended due to the high risk of vibration. For these reasons, among others, and because vibrations could break the steam supply and condensate drain 4 with a prior art pin gear located outside the bearing housing, the skilled artisan has not even contemplated the use of a pin gear as a drying cylinder drive.

The object of the invention is to provide a new and more advantageous drive device, particularly for drying cylinders with two-way condensate drainage with standing Zions.

The drive device according to the invention is characterized in what is stated in the characterizing part of claim 1.

In the actuator according to the invention, the drive gear is a pin gear mounted on the cylinder shaft at a point located between the cylinder end and the body. The pivot gear is supported on the foundation only through torque support. 15 In addition, the gear housing and bearing housing are coupled to each other in a manner that permits minor angular changes of the gearbox relative to the housing.

Preferably, the gap between the gearbox and the bearing housing is sealed with a flexible seal that allows minor angular changes of the gearbox relative to the body. Such a gasket may be, for example, a suitably sized o-ring gasket which provides the necessary '' living space ''.

The unsupported length of the steam supply and condensate drainage pipes can be reduced by connecting the gear housing and the bearing housing in succession so that there is no partition between them so that they have a common oil chamber. In this case, the position of the cylinder bearing remains substantially unchanged when the shaft in the arrangement does not extend from the present one.

In the solution according to the invention, the cylinder is mounted on the frame and through it to the foundation, and the drive gear is located on the shaft on the inside of the frame line, whereby the movements of the 30 cylinders with respect to the frame The motor is connected to the gearbox via the PTO shaft. The torque support 5 is only needed to ensure that the gear housing does not start rotating with the main gear. Thus, the body and cylinder can survive as temperatures change and minor changes in their position will have no effect on gear function.

5 The pivot gear to be mounted on the driven axle bracket is a technically simple and inexpensive gear type, which is also suitable for high speeds and allows for angular errors due to eg misalignment or sinking of the foundation. The pin gear is lighter and smaller in size than the DRG gear and is easier to handle, for example, when changing. The big 10 bearings used in the gear unit are smaller in size and have better price and availability than the DRG gear unit. Replacing the cylinder bearings is easy when the bearing housing is at the outermost axis of the shaft.

The solution according to the invention can extend the area of use of the pin gears with a fiber-15 press machine to extend to the drying cylinders, thereby providing a uniform operating solution throughout the dryer section, providing greater freedom of positioning and easier tension control of wire in the machine direction. A smoother wire tension is also reflected in improved runnability.

20

The invention will now be described in more detail with reference to the accompanying drawings, but examples of which are not to be construed as limiting.

Figure 1 is a side view of a drying cylinder with a prior art drive.

Figure 2 is an axonometric view of the drive-side end of the cylinder, which is provided with a drive device according to the invention.

Figure 3 is a cross-sectional view of an actuator according to the invention.

30 6

Figure 3A is an enlarged detail of detail A of Figure 3.

Fig. 4 is an example of the arrangement of conventional drives with a single wire dryer section 5.

Figure 5 is an example of the arrangement of the actuators of the invention with a single wire dryer section.

Fig. 1 schematically illustrates a conventional drying cylinder 10 provided with a DRG gear 19 with two-way drainage with standing Zions. The cylinder 10 comprises a cylindrical metal sheath 11 and two ends 12a, 12b, each of which is provided with a hollow shaft. The shafts associated with each of the ends 12a, 12b are supported on the foundation through the body 16a, 16b and a bearing housing 15 therein. The drive side shaft end 12a is provided with a vapor feed-introducing pipe 14, through which the sheath 11 is passed in from the heating steam. The shaft of each end 12a, 12b is provided with a condensate drain tube 15a, 15b through which the condensate collected by the siphons is removed from the cylinder 10.

20 On the drive side of the machine is a drive gear 19 which transmits the force required to rotate the cylinder 10 from the drive motor (not shown) to the shaft of the cylinder 10. The drive gear 19 is disposed here, as is known in the art, at an end of the shaft outside the body 16a, wherein the steam supply pipe 14 and the condensate drain pipe 15a are connected to the drive gear 19. Drive gear is a so-called 25 DRG gear mounted on the body and drives the cylinder 10 through a toothed sleeve.

The solution of Figure 1 is functional, supported by vibration, but it is expensive and a similar solution is not used elsewhere in the paper machine. Attaching the condensate drain pipe 15a in connection with the siphon to the drive after gear 19 is not a good solution as it increases the distance of the support point from the siphon, whereby vibration and vibration can disturb or even break siphon operation and thereby affect heat transfer to the cylinder. 11 and the drying capacity of the cylinder 10.

Figure 2 is an axonometric view of a portion of a drying cylinder 10 provided with an actuator according to the invention. The actuator comprises a body 16 through which the axis of the cylinder 10 is supported on the foundation and a drive gear 18 disposed between the body 16 and the end flange 12 of the cylinder 10. The drive gear 18 is a pin gear supported on the axis of the cylinder 10. In a manner known per se, the pin gear is connected to the foundation via a torque support (not shown). A drive pin 21 which engages with a drive motor (not shown) is ejected from the gear housing of the drive gear 18. The body 16 is provided with a support ring 22 for attaching a steam supply tube 14 for introducing heating steam into the cylinder 10 and a condensate discharge tube 15 for removing condensate from inside the cylinder 10 15.

Figure 3 shows in more detail the drive device according to the invention. The hollow shaft 13 is supported on the foundation by means of a body 16 housing a bearing housing 23 and support bearings 17. The shaft 13 can be secured to the cylinder end 12 shown in Fig. 20 2 by means of fastening screws 24 passing through a shoulder 25 of the shaft 13. The drive gear 18 comprises a main gear 26 and a drive gear 28 housed within the gear housing 20. The main gear 26 is mounted on the shaft 13 and tightened between the shoulder 25 and the bearing cap 23. The main gear 26 is surrounded by a gear housing 20 on which the main gear 25 26 is supported by bearings 27. Above the main gear 26 is shown a portion of the gear 28 connected to the drive pin 21 through which the driving force is applied to the main gear 26 and shaft 13. A bearing ring 22 is attached to the bearing housing 23 to which the steam supply pipe 14 and condensate drain pipe 15 shown in FIG.

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Fig. 3A is an enlarged detail of Fig. 3, illustrating in more detail the connection between the gear housing 20 and the bearing housing 23. The yoke housing 20 and the bearing housing 23 are not rigidly attached to each other. They are mounted successively on shaft 13 and a non-rotatable joint between them is sealed by o-5 ring gasket 29. There is a small gap between the opposite faces of gear housing 20 and bearing housing 23 to allow slight angular changes in gear 16 to bearing housing 26. The cylinder-side edge of the gear housing 20 is sealed relative to the shaft 13 by a first plurality of sealing rings 34 and the outwardly facing edge of the bearing housing 23 is sealed relative to the shaft 13 by a second labyrinth seal 35. This requires sealing between rotating and non-rotating bodies. A maze seal is an inexpensive and maintenance-free solution for sealing between a rotating shaft 13 and a non-rotating body 23, 27.

15

To save space, the gear housing 20 and the bearing housing 23 are connected to one another without an intermediate wall, whereby the oil chambers of the gear housing 20 and the bearing housing 23 are interconnected. The structure is very compact and allows rotation lubrication of bearings 27, 17 in gearbox 20 and bearing housing 23 with the same bearing oil-20. This can reduce the number of lubrication tubes and reduce possible leakage points out of the connected housing structure.

The assembly formed by the gear housing 20 and the bearing housing 23 (or body 16) is at least as short as the corresponding length of known drive gears, which eliminates the need to increase the length of the steam supply and condensate drain pipes passing through shaft 13. This reduces the risk of vibration of the steam supply and condensate drainage pipes and thus improves the reliability of cylinder operation. The vapor supply and condensate drainage retaining ring 22 is directly connected to the machine body 16, which also reduces vibration.

30 9

When the engagement between the gear unit 18 and the bearing housing 23 is flexible, the movements of the cylinder 10 relative to the body 16 have no effect on the operation of the gear gear 26, 28.

Fig. 4 schematically illustrates a prior art single-wire drying array with drying cylinders 10 in the top row and swivel rolls 30 in the bottom row. The winding line 36 illustrates the passage of the drying wire and web through the drying array, whereby for each cylinder 10 the web is closest to the surface of the cylinder 10 and for each swivel roll 30 is the wire closest to the surface 10 of the roll 30. The drying assembly is provided with a DRG gear 31 which uses the two last cylinders 10 in the direction of travel of the web, and a pin gear 32 which uses one of the rollers 30.

Fig. 5 shows a similarly sized drying group in which the final drying cylinder 10 of the group is provided with an actuator 33 according to the invention and two lower row swivel rolls 30 are provided with pin gear 32. The cylinder gears 10 and the swivel roller 30 are different in design and dimension. the bearings and their frames can be made from the same casting model.

20

The solution of the invention makes it possible to form groups of cylinders in which different cylinders have different speeds, which in turn can affect the tension of the wire.

Many variations of the invention are possible within the scope defined by the following claims.

Claims (4)

1. A drying cylinder (10) operating plant in a fiber web machine, the plant comprising: 5. a body (16) into which is fitted a bearing housing (23) for supporting cylinders (10) on its shaft (13) on a base, - a drive gear (18) for transmitting the driving force needed to drive cylinders (10) to the cylinder shaft (13), which drive gear comprises a gear (26, 28) and a gear (20), which gear unit (26, 28) is stored, and 10. a device (22) arranged in connection with the body (16) for attaching a pipe (14, 15) for supplying a meadow and / or removing condensation water at the storage housing (23) carrying the cylinder (10), characterized in that - the drive gear (18) is a tapping gear mounted on the cylinder shaft (13) in a position located between a end (12) on the cylinder (10) and the body (16), which drive gear (18) is supported on the base only by means of a torque support, and - the gearbox (20) and bearing housing uset (23) are connected to each other in such a way that a gap is created between them which allows small angular changes of the drive gear (18) in the relation to the body (16). 2. Operating system according to claim 1, characterized in that the gap which arises between the gearbox (20) and the bearing housing (23) is sealed with an elastic seal (29), which allows slight angular changes of the drive gear (18) in relation to the body (16). ). Operating system according to claim 1 or 2, characterized in that there is no partition between the gearbox (20) and the bearing housing (23), whereby their oil chambers interfere with each other. 30 4. Operating system according to claim 3, characterized in that the gearbox (20) and the bearing housing (23) are sealed to the cylinder shaft (13) with maze seals (34, 35) and to each other with an o-ring seal (29) or equivalent. 5