EP2573262A1 - Device for tensioning an endless sheet of material - Google Patents

Abstract

The device has a tension roller (2) guiding a continuous web (1). The tension roller is mounted in carriages (3, 4) to adjust tension of the web. The carriages are guided on respective gear racks (5, 6). The carriages are interconnected with each other by a drivable transverse shaft (9) such that the carriages are synchronously displaced. A motor (7) e.g. electrical self-locking motor, drives the transverse shaft. A gearing (10) e.g. toothed-wheel gearing and reduction gearing, is arranged in one of the carriages and provided between the transverse shaft and the gear racks.

Description

The invention relates to a device for tensioning an endless web, in particular for clamping machine wires or dry felts of a paper, board or tissue machine.

Such devices for tensioning an endless web (also called a wire tensioner) have at least one tensioning roller for guiding the web. By moving the tension roller, the web can be stretched or relaxed.

The invention has for its object to provide a device for tensioning an endless web, which is used variably and structurally simple and allows an exact adjustment of the web tension.

This object is achieved by a device having the features of patent claim 1. Advantageous embodiments are described in the subclaims.

According to the invention, the device for tensioning an endless web, in particular for tensioning machine wires or dry felts of a paper, board or tissue machine, has at least one tensioning roller for guiding the web. The tension roller is mounted to adjust the tension of the web in at least two, each on a rack guided car. The cars are connected to each other via a drivable transverse shaft for synchronous displacement of the car. A motor is provided to drive the cross shaft. Further, in at least one of the cars is a Gear, in particular a gear transmission, provided between the transverse shaft and the rack.

The guidance of the two carriages in the respective rack and the synchronization of the displacement of the carriages by the transverse shaft lead to a reproducible and uniform displacement of the tensioning roller and thus to a controlled and uniform stress build-up or degradation within the track. By using a motor as a drive source for the rotational movement of the transverse shaft, a particularly precisely defined movement (speed, angle of rotation) can be realized. The transmission allows a change (adjustment) of the engine speed and the engine torque to the required displacement speed of the car or to the required displacement torque. Overall, the device thus allows an exact adjustment of the web tension, the components used to lead to a variably usable and structurally simple design device.

Advantageously, in this case the transmission is provided in each of the car between the cross shaft and the respective rack. That each of the carriages is equipped with a gear which is provided between the cross shaft and the respective rack.

In an advantageous embodiment, the transmission is designed as a reduction gear. In this way, the transmission makes it possible to convert the relatively high engine speeds of conventional engines into a relatively slow displacement motion - as normally required in the adjustment of web tension. At the same time the output torque of the motor is increased accordingly, so that a relatively small motor can be used to generate the torque required for the displacement of the car.

Since the reduction gear is arranged here between the cross shaft and the rack, the cross shaft still rotates with the engine speed and the speed reduction takes place only then in the transmission. This has the advantage that the torque to be absorbed by the transverse shaft is relatively low. Accordingly thin the cross shaft can be designed, which reduces the design effort and leads to a material and cost savings.

In a further advantageous embodiment, the transmission has a drive pinion, which sits on the cross shaft, and a driven gear, which is in engagement with the rack on. In this way, the transmission directly connects the cross shaft with the rack. This makes a compact and space-saving configuration possible.

In a particularly advantageous embodiment, the drive pinion is in engagement with a first intermediate gear, which has a larger number of teeth than the drive pinion and which is disposed on an intermediate shaft lying parallel to the cross shaft, wherein on the intermediate shaft, a second intermediate gear, which has a smaller number of teeth than that first intermediate has, is arranged. Further, the second idler gear is engaged with a third idler gear which has a larger number of teeth than the second idler gear and which is disposed on an output shaft parallel to the intermediate shaft. In addition, the output gear is arranged on the output shaft. By such a configuration of the transmission, an effective reduction of the engine speed to the time required for the displacement of the carriage along the rack relatively low speeds is possible. At the same time a compact design of the transmission is possible.

Advantageously, the transmission is mounted on roller bearings in the car. As a result, a particularly durable and low-friction mounting of the transmission is possible. To further increase the life of the transmission and reduce friction loss, the transmission may be equipped with a lubricant supply means (e.g., grease nipple).

In a further advantageous embodiment, the transverse shaft is guided in a fixedly connected to the carriage hollow profile element. In this way, the transverse wave is shielded from the environment and the rotational movement of the transverse shaft is protected. In addition, the transverse shaft can be mounted within the hollow profile element at least one bearing point. This increases the stability of the crosswave and can prevent the occurrence of natural resonances of the crosswave or shift to not occurring in operation frequency ranges.

Advantageously, the engine is positioned on one of the carriages. Here, the engine, in particular a motor output shaft, be arranged coaxially with the transverse shaft. In this way, a direct driving of the transverse shaft by the motor without the interposition of other elements is possible.

The engine is advantageously designed as an electric motor. However, it is also possible to use a hydraulically or pneumatically operated engine. Furthermore, the motor may be designed as a self-locking motor.

In a further advantageous embodiment, the motor is rotatably mounted and connected to a device for detecting the reaction torque. In this way it is possible to determine the tension of the endless web by means of the reaction torque and to control the motor accordingly.

In a further advantageous embodiment, a force measuring sensor, in particular a load cell and / or one or more strain gauges, is provided for detecting the forces acting on the tension roller, and the force measuring sensor is connected to a control device for adjusting the tension of the web.

Advantageously, the racks are stored protected between guide profiles and / or the racks are covered with a steel band over its entire length against contamination.

Fig. 1

eine erste Ausführungsform einer Vorrichtung zum Spannen einer endlosen Bahn;

Fig. 2

eine erste Alternative für eine Vorrichtung zur Reaktionsdrehmoment-Erfassung innerhalb der in Fig. 1 dargestellten Ausführungsform der Vorrichtung zum Spannen einer endlosen Bahn;

Fig. 3

eine alternative Lagerung des Motors ohne eine Vorrichtung zur Reaktionsdrehmoment-Erfassung;

Fig. 4

eine teilweise geschnittene Draufsicht auf eine zweite Ausführungsform einer Vorrichtung zum Spannen einer endlosen Bahn;

Fig. 5

eine vergrößerte Darstellung des Bereichs X aus Fig. 4; und

Fig. 6

eine Seitenansicht einer Vorrichtung zum Spannen einer endlosen Bahn.

The invention is further explained by means of embodiments in the drawing figures. The same or equivalent parts are provided here in the various drawings with the same reference numerals. Show, in each case schematically,

Fig. 1

a first embodiment of an apparatus for tensioning an endless web;

Fig. 2

a first alternative for a device for reaction torque detection within the in Fig. 1 illustrated embodiment of the device for tensioning an endless web;

Fig. 3

an alternative storage of the engine without a device for reaction torque detection;

Fig. 4

a partially sectioned plan view of a second embodiment of an apparatus for tensioning an endless web;

Fig. 5

an enlarged view of the area X from Fig. 4 ; and

Fig. 6

a side view of an apparatus for tensioning an endless web.

Fig. 1 shows a section of, for example, a known per se dryer section of a paper machine. Within this drying section, an endless web 1, for example a machine wire, a drying wire or a dry felt of a paper machine, is guided over a tensioning roll 2 known per se. The tension roller 2 is rotatably supported at its two axial ends in a carriage 3 and 4, respectively. The carriages 3, 4 are each guided on a rack 5 and 6, respectively. By moving the carriage 3, 4 along the racks 5, 6, the tension roller 2 can be moved in the direction of R1. The displacement of the tension roller 2 in the direction of R1 in turn causes the construction or degradation of a voltage in the web. 1

To move the carriage 3, 4 along the racks 5, 6 is a motor 7, wherein this is designed as an electric, self-locking motor. The motor 7 is fixed to the carriage 3 and has an engine output shaft 8. The motor output shaft 8, whose direction of rotation is represented by the directional arrow R2, drives a cross shaft 9 arranged coaxially therewith. The cross shaft 9 is used to synchronize the sliding movement of the carriage 3, 4 along the rack 5 and 6 and transmits the drive power of the motor 7 to the two cars 3, 4. For this purpose, the transverse shaft 9 in both the car 3 and in the car 4 through Rolling bearings rotatably mounted.

In the carriage 3, 4, a gear 10 is provided between the transverse shaft 9 and the rack 5 and 6, respectively. The transmission 10 is formed in the embodiments as a reduction gear transmission. In Fig. 1 is only one of the transmission 10 in a schematic manner by three illustrated gears shown in dashed lines. The transmission 10 translates the input speed output by the engine 7 through one or more reduction stages into an output speed reduced relative to the input speed. In this way, the existing in conventional motors relatively large speeds are broken down with a corresponding increase in the torque to the process of the car 3, 4 along the rack 5 and 6 sufficient relatively low travel speed.

The transverse shaft 9 is surrounded by a hollow profile element 11. The hollow profile element 11 has a square outer profile and is hollow, so that the transverse shaft 9 can rotate relative to the hollow profile element 11 in the direction of rotation R3. The hollow profile element 11 is connected at its axial ends in each case with one of the carriages 3, 4. In this way, the hollow profile element 11 is spatially stationary, while the positioned within the hollow profile element transverse shaft 9 can rotate. Not shown in the figures are bearing points in which the transverse shaft 9 is supported for supporting and to avoid vibrations via, for example, a rod guide and / or a rolling bearing in the hollow profile element 11.

The motor 7 is rotatably mounted in the carriage 3 by a rolling bearing and connected via a lever 12 with a compression spring 13. Upon activation of the motor 7 takes place a rotation of the transverse shaft 9, a translation of the rotational movement through the gear 10, a displacement of the carriage 3, 4 along the racks 5, 6, a method of the tension roller 2 in the direction of R1 and a corresponding stress buildup or Degradation within the web 1. In response to this occurs at the same time a reaction force, which acts back in the reverse direction of the tension roller 2 to the motor 7. Due to the rotatable mounting of the motor 7, this experiences a reaction torque in the direction R2. The attached to the motor 7 lever 12 undergoes a rash in the direction R4, creating a Clamping path change to the compression spring 13 occurs. This tension change is detected by a known per se displacement measuring system (not provided in the figures with a reference numeral) and is also a measure of the existing in the web 1 voltage as a measure of the reaction torque determined. After determining the reaction torque via the displacement measuring system, the reaction torque can be controlled within predetermined limits, whereby the voltage in the web 1 can be adjusted and / or stabilized. The system consisting of the motor 7, the lever 12, the compression spring 13 and the displacement measuring system thus forms a device for reaction torque detection.

The tensioning roller 2 is equipped at its bearing points in the carriage 3, 4 with a known force measuring sensor 14 (load cell, strain gauges, or the like). Based on the measurement data of this force measuring sensor 14, a control device (not shown in the figures) can set a desired tension within the web 1 by correspondingly driving the motor 7 and then displacing the carriages 3, 4 along the racks 5, 6.

The transmission 10 is mounted within the carriage 3, 4 by rolling bearings and provided with a lubricant supply means (not shown in the figures).

Fig. 2 shows an alternative embodiment for a device for reaction torque detection. The engine 7 is also equipped with a lever 12. The lever 12 is in communication with a force measuring sensor 15. Upon the occurrence of a reaction torque in the direction R2, the lever 12 mounted on the motor 7 undergoes a deflection in the direction R4. This rash is detected by the known force measuring sensor 15. The signals of the force measuring sensor 15 can then serve to determine the reaction torque. The System consisting of the motor 7, the lever 12 and the force measuring sensor 15 thus forms another device for reaction torque detection.

Fig. 3 shows an alternative form of storage of the motor 7 without a device for reaction torque detection. The engine 7 is also equipped with a lever 12. The lever 12 is connected to a fixed bearing 16 in connection. Upon the occurrence of a reaction torque in the direction R2, although the lever 12 attached to the motor 7 experiences a corresponding torque, the movement of the lever 12 in the direction R4 is suppressed by the fixed bearing 16.

Fig. 4 shows a partially sectioned plan view of a second embodiment of an apparatus for tensioning an endless web 1. The embodiment of Fig. 4 differs from the embodiment Fig. 1 essentially by the configuration of the hollow profile element 11 or 111. While the hollow profile element 11 from Fig. 1 has a square outer profile, has the hollow profile element 111 from Fig. 4 a round outer diameter. Further missing in the embodiment according to Fig. 4 in the Fig. 1 illustrated device for reaction torque detection. The remaining components of the device correspond to those of Fig. 1 , In the Fig. 1 only schematically illustrated components "gear" and "engine" are in Fig. 4 Shown in more detail below and in relation to Fig. 5 described.

Fig. 5 shows an enlarged view of the area X from Fig. 4 , The engine 7 has an engine output shaft 8. This engine output shaft 8 is directly connected to the transverse shaft 9, so that the motor 7 drives the transverse shaft 9 directly. The transmission 10, which is provided between the transverse shaft 9 and the rack 5, is designed as a reduction gear transmission. The transmission 10 has a drive pinion 17, a first idler 18, a second idler 19, a third idler 20, and a driven gear 21. The first pinion 18 is in engagement with the drive pinion 17 and has a larger number of teeth than the drive pinion 17. Further, the first intermediate 18 is disposed on an intermediate shaft 22. The intermediate shaft 22 is formed parallel to the transverse shaft 9 and mounted in the carriage 3 by rolling bearings. The second intermediate gear 19 is also seated on the intermediate shaft 22 and has a smaller number of teeth than the first intermediate 18. The second idler 19 is in engagement with the third intermediate 20. The third idler 20 has a larger number of teeth than the second idler 19 and sits on an output shaft 23. The output shaft 23 is supported by bearings in the carriage 3 and parallel to the intermediate shaft 22 - and thus also parallel to the transverse shaft 9 - arranged. The output gear 21 has a smaller number of teeth than the third intermediate 20. Further, the output gear 21 is in engagement with the rack 5 and transmits the rotational movement of the transmission 10 in a linear displacement of the carriage 3 along the rack 5.

Fig. 6 shows a side view of an apparatus for tensioning an endless web 1. The components of the device Fig. 6 correspond to those of the embodiments Fig. 1 respectively. Fig. 4 so that a detailed description is omitted. The tension roller 2 is mounted in the carriage 3. The carriage 3 is displaceable along the rack 5. By the displacement of the carriage 3 along the rack 5, the tension roller is moved in the direction of R1. In this way, a stress build-up or - degradation in the web 1 is possible, ie the web 1 is stretched as needed. For displacement of the carriage 3 along the rack 5, the motor 7 (in Fig. 6 not shown), the speed and torque is adjusted by means of the transmission 10. The motor 7 drives the drive pinion 17. The Drive pinion 17 is engaged with the first intermediate gear 18. The second intermediate gear 19 is seated together with the first intermediate gear 18 on the intermediate shaft 22 and is in engagement with the third intermediate gear 20. The third intermediate gear 20 is like the driven gear 21 on the output shaft 23. The driven gear 21 is in engagement with the rack. 5

LIST OF REFERENCE NUMBERS

1

endless track

2

tension roller

3, 4

dare

5, 6

rack

7

engine

8th

Engine output shaft

9

cross shaft

10

transmission

11

Sectional element

12

lever

13

compression spring

14, 15

Load Sensor

16

fixed bearing

17

pinion

18, 19, 20

idler

21

output gear

22

intermediate shaft

23

output shaft

111

Sectional element

R1-R4

direction

Claims (14)

Device for tensioning an endless web (1), in particular for tensioning machine wires or dry felts of a paper, board or tissue machine, with at least one tensioning roller (2) for guiding the web (1),
wherein the tensioning roller (2) is mounted for setting the tension of the web (1) in at least two carriages (3, 4), each guided on a rack (5, 6),
the carriages (3, 4) being connected to one another via a drivable transverse shaft (9) for the synchronous displacement of the carriages (3, 4),
wherein a motor (7) is provided for driving the transverse shaft (9), and wherein in at least one of the carriages (3, 4) a transmission (10), in particular a gear transmission, between the transverse shaft (9) and the rack (5, 6) is provided. Apparatus according to claim 1, wherein the transmission (10) is designed as a reduction gear. Device according to one of the preceding claims, wherein the transmission (10) has a drive pinion (17) which sits on the transverse shaft (9) and a driven wheel (21) which is in engagement with the rack (5, 6) , Apparatus according to claim 3, wherein the drive pinion (17) is engaged with a first intermediate gear (18) which has a larger number of teeth than the drive pinion (17) and which is disposed on an intermediate shaft (22) parallel to the transverse shaft (9) , located,
wherein on the intermediate shaft (22) a second intermediate wheel (19) which has a smaller number of teeth than the first intermediate wheel (18) is arranged,
wherein the second intermediate gear (19) is engaged with a third idler gear (20) having a larger number of teeth than the second idler gear (19) and which is disposed on an output shaft (23) parallel to the intermediate shaft (22), and wherein the driven gear (21) is arranged on the output shaft (23). Device according to one of the preceding claims, wherein the transmission (10) is mounted in the carriage via rolling bearings. Device according to one of the preceding claims, wherein the transverse shaft (9) in a fixed to the carriage (3, 4) connected to the hollow profile element (11, 111) is guided. Apparatus according to claim 6, wherein the transverse shaft (9) within the hollow profile element (11, 111) is mounted on at least one bearing point. Device according to one of the preceding claims, wherein the motor (7) is positioned on one of the carriages (3, 4). Device according to one of the preceding claims, wherein the motor (7) has a motor output shaft (8) which is aligned coaxially with the transverse shaft (9) and the motor (7) directly drives the transverse shaft (9). Device according to one of the preceding claims, wherein the motor (7) is designed as a self-locking motor. Device according to one of the preceding claims, wherein the motor (7) is rotatably mounted and connected to a device for detecting the reaction torque. Device according to one of the preceding claims, wherein the transmission (10) is equipped with a lubricant supply device. Device according to one of the preceding claims, wherein the gear (10) in each of the carriages (3, 4) between the transverse shaft (9) and the respective rack (5, 6) is provided. Device according to one of the preceding claims with a force measuring sensor (14), in particular a load cell or a strain gauge, for detecting the forces acting on the tension roller (2) and with a control device for adjusting the tension of the web (1), wherein the Control / regulating device is connected to the force measuring sensor.

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