Regulating section, method for operating a regulating section and method for retrofitting a regulating section

Abstract

The invention relates to a regulating section (1) with a drafting unit (4) comprising several roller combinations (6, 6', 6") arranged in series for drawing a fiber web (7) to be processed, and with a drive unit (8) for driving the several roller combinations (6, 6', 6"), wherein the drive unit (8) comprises: a main motor (9) for driving at least one first roller combination (6") at a constant speed with a main speed, and a regulating motor (17) for regulating the speed of at least one second roller combination (6, 6'), wherein by regulating the speed of the second roller combination (6, 6') it is possible to change from a basic speed dependent on the main speed to a regulating speed independent of the main speed and thus to adjust the drawing of the fiber web (7).The regulating section (1) according to the invention is characterized in that the regulating motor (17) is designed to be drive-independent of the main motor (9) and, based on an electrical signal (18) that depends on the main speed, drives the second roller combination (6, 6') independently of the main motor (9) at the regulating speed. Furthermore, the invention relates to a method for operating and a method for converting a regulating section (1).

Description

[0001] The present invention relates to a regulating line with a drafting unit comprising several roller combinations arranged in series for drawing a nonwoven fabric to be processed, and with a drive unit for driving the several roller combinations, wherein the drive unit comprises: a main motor for driving at least one first roller combination at a constant speed and a regulating motor for regulating the speed of at least one second roller combination, wherein the speed of the second roller combination can be changed from a base speed dependent on the main speed to a regulating speed independent of the main speed, and thus the drawing of the nonwoven fabric can be adjusted. The invention further relates to a method for operating a regulating line and a method for retooling a regulating line.

[0002] From EP 2 149 628 A1, a regulating system is known which has a main motor for driving at least two roller assemblies and a regulating motor for the superimposed drive of at least one of the roller assemblies. A differential gear, connected on one side to the main motor and on the other to the regulating motor, allows the regulating motor to superimpose its base speed on the main motor. This has the disadvantage that the differential gear is very maintenance-intensive and, especially with increasing operating time, very prone to breakdowns. Furthermore, the main motor and / or regulating motor used here can only be maintained or replaced with a very high level of technical effort.

[0003] A spinning machine and a start control device are known from JP 408 120 528 A. A drafting machine with a drive and a regulating device is known from WO 99 / 11847 A1. Regulating sections according to the Sand der Technik are also known from US 5 428 870 A, US 2001 / 005923 A1 and XP093283898.

[0004] The object of the present invention is to eliminate the disadvantages known from the prior art.

[0005] The problem is solved by a regulating system, a method for operating a regulating system, and a method for converting a regulating system with the features of the independent patent claims.

[0006] A regulating section is proposed, featuring a drafting unit with several roller combinations arranged in series for drawing a nonwoven fabric to be processed, and a drive unit to power these multiple roller combinations. The roller combinations typically consist of pairs of two rollers and / or arrangements of three rollers. The drafting unit usually comprises three roller combinations, which can be designated as the infeed roller combination, the intermediate roller combination, and the outfeed roller combination. A number of fiber ribbons typically enter the infeed roller combination, where the nonwoven fabric to be processed is formed by compressing the incoming fiber ribbons. The nonwoven fabric is then drawn in the drafting unit, with the infeed roller combination and the intermediate roller combination usually forming a pre-drawing section.The middle roll combination and the exit roll combination usually form a main distortion area.

[0007] The drive unit comprises a main motor for driving at least one first roller assembly at a constant speed. Furthermore, the drive unit includes a regulating motor for regulating the speed of at least one second roller assembly. This regulating motor allows the speed of the second roller assembly to be varied from a base speed dependent on the main speed to a regulating speed independent of the main speed, thus enabling adjustment of the fiber web's distortion. The main motor drives the output roller assembly, ensuring it operates at a constant speed or delivery rate. The regulating motor preferably drives the input roller assembly and / or the intermediate roller assembly.

[0008] According to the invention, the regulating motor is designed to be drive-independent of the main motor and, based on an electrical signal dependent on the main motor speed, drives the second roller assembly at the regulating speed independently of the main motor. Drive-independent here means that the rotary motion of the regulating motor is mechanically independent of the main motor. The respective output elements of the regulating motor and the main motor are designed to rotate independently of each other.

[0009] The base speed of the regulating motor depends directly on the main speed of the main motor. The electrical signal, which depends on the main speed, is passed directly or indirectly from the main motor to the regulating motor. Based on this electrical signal, the regulating motor is driven at the regulating speed, which can differ from the base speed.

[0010] As described above, the main motor drives at least one first roller assembly at a constant main speed. The base speed of the regulating motor is based on the main speed of the main motor. When the regulating motor drives at least one second roller assembly at the base speed, the regulating section is operated with a predefined draft. To change the draft in the drafting unit, the base speed can therefore be replaced by a variable regulating speed.

[0011] Because the regulating motor drives the second roller assembly based on the electrical signal, which depends on the main rotational speed, no mechanical transmission of the speed, for example via belt drives, is necessary. A complex drive unit with a differential gear can therefore be eliminated. Furthermore, the electrical signal can be easily manipulated to adjust and / or change the regulating speed and / or the base speed.

[0012] The drive unit features a speed sensor for measuring the rotational speed of at least one first roller assembly and / or the main motor. The speed sensor can thus directly detect the main rotational speed of the first roller assembly at the assembly itself and / or calculate it from the rotational speed of the main motor. This allows for a very simple and accurate determination of the main rotational speed. Furthermore, when converting a control system with a mechanical differential gear, an existing speed sensor can be reused and / or the speed sensor can be easily retrofitted.

[0013] The drive unit includes at least one transmission unit for converting the rotational speed detected by the speed sensor into the base speed of the second roller assembly. As described above, the detected rotational speed can be the main rotational speed and / or the speed of the main motor. The transmission unit converts the detected rotational speed using a constant gear ratio, so that the resulting base speed is directly dependent on the main rotational speed. Alternatively, the transmission unit can be integrated into the speed sensor, which then outputs the base speed as an electrical signal. The base speeds of several second roller assemblies, such as an input roller assembly and an output roller assembly, can differ from one another. Transmission elements and / or belt drives, for example, can be used to convert the rotational speeds.

[0014] It is advantageous if the regulating section includes a pair of sensing rollers for measuring the thickness of at least one fiber strip entering the drafting unit. The pair of sensing rollers is positioned upstream of the incoming roller assembly, so that the thickness of the at least one incoming fiber strip can be determined before a fiber web is formed from it.

[0015] It is also advantageous if the control section includes a preset unit that is electrically connected to the pair of sensing rollers and specifies a superimposed speed and / or determines it from the thickness of at least one fiber strip. As described above, the draft of the drafting unit is adjusted based on the thickness of the incoming fiber strips. The preset unit can determine the superimposed speed from the thickness measured by the pair of sensing rollers. This superimposed speed is necessary to achieve uniform or the desired draft of the fiber web by superimposing it on the base speed of the control motor.

[0016] Furthermore, it is advantageous if the drive unit includes a control unit for calculating the regulating speed and / or controlling the regulating motor. The control unit preferably adds the base speed output by the transmission unit to the superimposed speed output by the input unit. It is also conceivable that the control unit is operatively connected to a quality sensor downstream of the drawing unit, so that the drawn fiber strip is checked for quality before being deposited into the can. In this way, for example, the regulating speed can be set based on the quality of the drawn fiber strip.

[0017] It is also advantageous if the drive unit has at least one transmission line for transmitting the electrical signal between the regulating motor, the main motor, the speed sensor, the transmission unit, the guide roller pair, the setpoint unit, and / or the control unit. This transmission line can serve to transmit the electrical signal. It is also conceivable that the signal transmission could be carried out using a transmitter / receiver unit, so that the electrical signal is transmitted wirelessly or via radio.

[0018] It is also advantageous if the control unit is electrically connected to the setpoint unit, the translation unit and / or the regulating motor in such a way that the regulating speed is calculated from the superimposed speed and the base speed and / or transmitted as an electrical signal to the regulating motor.

[0019] It also offers advantages if the main motor is designed as an asynchronous motor and / or the regulating motor as a reluctance motor. The main motor as an asynchronous motor has the advantage of maintaining a nearly constant speed. Furthermore, it has a very robust design and is cost-effective to manufacture. The regulating motor as a reluctance motor, especially as a synchronous reluctance motor, has the advantage of a simple and straightforward design, making it very reliable and cost-effective to operate. The synchronous reluctance motor is preferably operated with a frequency converter, which is, for example, integrated into the control unit. This allows for a very high efficiency.

[0020] Furthermore, a method for operating a regulating section is proposed. In this method, a fiber web to be processed is drawn using a drafting unit comprising several roller combinations arranged in series, and the several roller combinations are driven by a drive unit. A main motor of the drive unit drives at least one first roller combination at a main speed. A regulating motor of the drive unit regulates the speed of at least one second roller combination, whereby the speed of the second roller combination is changed from a base speed dependent on the main speed to a regulating speed independent of the main speed, thus adjusting the drawing of the fiber web.

[0021] According to the invention, the regulating motor drives the second roller combination at the regulating speed independently of the main motor, based on an electrical signal that depends on the main speed.

[0022] Because the regulating motor drives the second roller assembly based on the electrical signal, which is dependent on the main speed, no mechanical transmission of the speed is necessary. As described above, a differential gear is therefore no longer required in the drive unit. This eliminates the mechanical transmission of the speed from the main motor to the second roller assembly. Furthermore, the electrical signal can be easily manipulated to adjust and / or change the regulating speed and / or the base speed.

[0023] It is advantageous if the control section is designed according to the preceding and / or following description, whereby the mentioned features can be present individually or in any combination.

[0024] Furthermore, a method for converting a regulating section is proposed. In this conversion method, the regulating section comprises a drafting unit with several roller combinations arranged in series for drawing a nonwoven fabric to be processed. The regulating section also includes a drive unit for powering the multiple roller combinations. The drive unit comprises a main motor for driving at least one first roller combination at a constant speed. The drive unit further includes a differential gear for transmitting the speed of the main motor to at least a second roller combination, such that the base speed of the second roller combination depends on the main speed of the first roller combination.In addition, the drive unit includes a superposition motor for superimposing the base speed with a superposition speed by means of the differential gear, so that by superimposing the speed of at least one second roller combination can be changed from the base speed to a regulating speed and thus the distortion of the fiber web can be adjusted.

[0025] The differential gear is preferably designed as a planetary gear set, enabling three-shaft operation. The differential gear has a first drive element driven by the main motor. A second drive element of the differential gear is driven by the superimposed motor. At least one second roller assembly can be driven by means of an output element of the differential gear.

[0026] According to the invention, the differential gear is removed from the drive unit and the superimposed motor is replaced by a regulating motor that is independent of the main motor, wherein, after installation in the regulating section, the regulating motor drives the second roller combination at the regulating speed independently of the main motor based on an electrical signal that depends on the main speed.

[0027] The modifications to the drive unit of the regulating section described above allow the removal of the failure-prone mechanical differential gear. The regulating motor then drives the second roller assembly mechanically, independently of the main motor, thus eliminating the need for superimposed speeds. This results in lower maintenance for the regulating section after the conversion.

[0028] It is advantageous if the control section is designed after the conversion according to the preceding description, whereby the mentioned features can be present individually or in any combination.

[0029] It is also advantageous if at least one drive element and / or output element of the differential gear is reused as a transmission element of the regulating motor. Drive elements here are components of the differential gear removed during the conversion, which are driven by the main motor and / or the superimposed motor. Such drive elements can be, for example, drive shafts and / or drive pulleys. These drive elements are often connected to the superimposed motor and / or the main motor via belt drives. An output element is a component that connects the differential gear to the second roller assembly and drives it. Here, too, an additional belt drive can be provided to increase the speed.

[0030] In a mechanical differential gear, at least one drive element and / or output element can be designed to adjust the gear ratio. Different sizes of the at least one drive element and / or output element can thus lead to different rotational speeds of the second roller assembly. This may be necessary, for example, when changing the material of the fiber strip(s) to adjust the main draft and / or the pre-draft. This adjustment of the main draft and / or pre-draft is independent of the regulation and therefore represents a permanent change in the draft.

[0031] The transmission element of the regulating motor is understood to be an element that is either directly mounted on the regulating motor or indirectly arranged between the regulating motor and the at least one second roller assembly, such that the transmission element can increase the rotational speed to the second roller assembly. By reusing the at least one drive element and / or output element as the transmission element of the regulating motor, the permanent transmission ratios used in the regulating system with differential gear and superimposed motor can be very easily adapted to the regulating system with an independent regulating motor.

[0032] It is also advantageous to remove the mechanical or electromagnetic brake from the drive unit. This brake is typically used to slow the superimposed motor, ensuring that at least one other roller assembly operates at its base speed. Removing the superimposed motor renders the brake unnecessary, allowing for electronic speed control. The control unit is then used to regulate the speed. Thus, removing the brake eliminates another component subject to wear (in addition to the differential gear).

[0033] Further advantages of the invention are described in the following exemplary embodiments. These show: Figure 1 a schematic representation of a control system according to the state of the art, and Figure 2 a schematic representation of a regulating system according to the invention.

[0034] Figure 1Figure 1 shows a schematic representation of a regulating section 1 according to the prior art. In the regulating section 1, one or more supplied fiber ribbons 2 are homogenized and stretched in a known manner and then deposited in a container (not shown). The fiber ribbons 2 are fed to a drawing unit 4 via a pair of guide rollers 3.

[0035] It is also possible that the fiber strips 2 are compressed into a fiber strip 2 by means of a compressor (not shown here) before being fed to the pair of guide rollers 3. The drafting unit 4 comprises several roller combinations 6, 6', 6". arranged one behind the other. The roller combinations 6, 6', 6" are designed to draw a fiber web 7 formed from the at least one fiber strip 2.

[0036] The roll combinations 6, 6', 6" can be configured as pairs of rolls with two rolls or as a roll combination with three rolls. In the illustrated embodiment, three roll combinations 6, 6', 6" are provided in the form of an input roll combination 6, a middle roll combination 6', and an output roll combination 6".

[0037] The infeed roll combination 6 and the intermediate roll combination 6' form a pre-drawing section. The intermediate roll combination 6' and the outfeed roll combination 6" form a main drawing section. All roll combinations 6, 6', 6" are driven by a drive unit 8.

[0038] In the illustrated embodiment, the output roll assembly 6" is driven at a constant speed by a main motor 9 of the drive unit 8 as the first roll assembly 6". The output roll assembly 6" rotates at a constant main speed. The input roll assembly 6 and the intermediate roll assembly 6' are each designed as second roll assemblies 6, 6' and are regulated.

[0039] As described above, the exemplary embodiment of the Figure 1around the regulating section 1 according to the prior art, in which a differential gear 10 transmits the rotational speed of the output roller assembly 6" to the input roller assembly 6 and to the intermediate roller assembly 6', such that a basic rotational speed of the input roller assembly 6 and the intermediate roller assembly 6' depends on the main rotational speed of the output roller assembly 6". The differential gear 10 can, for example, be designed as a planetary gear set.

[0040] The differential gear 10 comprises a first drive element 11, a second drive element 12, and an output element 13. The first drive element 11, powered by the main motor 9, provides a constant rotational speed. This constant speed drives the input roll assembly 6 and the intermediate roll assembly 6' at their base speed. The second drive element 12, powered by a superimposed motor 14, provides a superimposed rotational speed. By superimposing the base speed with the superimposed rotational speed, the input roll assembly 6 and the intermediate roll assembly 6' are driven at a regulated rotational speed. The regulated rotational speed is thus essentially the sum of the base speed and the superimposed rotational speed. For this purpose, the input roll assembly 6 and the intermediate roll assembly 6' are connected to the output element 13.

[0041] Different drive shafts for the 6, 6', 6" roller combinations can achieve different rotational speeds, which can result in differences in the base speed and / or the regulated speed of the 6, 6' roller combinations. Additional gear ratios and / or belt drives can also be used for the individual 6, 6', 6" roller combinations, which can also lead to differences in rotational speed.

[0042] By changing the superposition speed and thus the control speed, the distortion of the fiber web 7 can be adjusted or changed. In particular, changing the control speed alters the main distortion from the intermediate roll combination 6' to the output roll combination 6". The thickness of the incoming fiber webs 2 is thus detected by the sensing roller pair 3. The sensing roller pair 3 is electrically connected to a control unit 15, which sets the superposition speed for the superposition motor 14 and / or determines it from the thickness of the fiber web 2. The control unit 15 is also electrically connected to the superposition motor 14.

[0043] Furthermore, the drive unit 8 has a brake 16 in the area of ​​the differential gear 10 or between the differential gear 10 and the superimposed motor 14, which can completely brake the superimposed motor 14 and / or the second drive element 12. This allows the current rotational speed of the input roller combination 6 and the intermediate roller combination 6' to be reduced to the base speed as quickly as possible.

[0044] It should also be noted that the representation of drive unit 8 is of the Figure 1 and also the following Figure 2 These are highly simplified models. The belt drives, drive elements, output elements, and transmission elements on the main motor 9, the superimposed motor 14, the differential gear 10, the gauge roller pair 3, and the roller combinations 6, 6', 6" are shown purely schematically.

[0045] Figure 2shows a schematic representation of a control section 1 according to the invention. In comparison to the exemplary embodiment of the Figure 1 According to the prior art, the differential gear 10 was removed and the superimposed motor 14 was replaced by a regulating motor 17 that is independent of the main motor 9. This allows the regulating motor 17 to drive the input roller assembly 6 and the intermediate roller assembly 6' at the regulating speed independently of the main motor 9, based on an electrical signal 18 that depends on the main speed. The regulating motor 17 is preferably designed as a reluctance motor. The main motor 9 is preferably designed as an asynchronous motor, so that it is driven at a constant speed.

[0046] In the area of ​​the main motor 9 and / or the output roller assembly 6" of the regulating section 1 according to the invention, a speed sensor 19 is arranged for detecting the speed of the main motor 9 and / or the output roller assembly 6". The speed sensor 19 is electrically connected to a transmission unit 20, for example by means of transmission lines, which translates the detected speed into the base speed of the input roller assembly 6 and / or the intermediate roller assembly 6' or into the speed of the regulating motor 17 required for this purpose.

[0047] Furthermore, the drive unit 8 of the control section 1 according to the invention in the illustrated embodiment has the Figure 2A control unit 21 is provided, which can calculate and control the regulating speed of the regulating motor 17. For this purpose, the control unit 21 is electrically connected to the input unit 15, the transmission unit 20, and the regulating motor 17. The control unit 21 calculates the regulating speed based on the base speed from the transmission unit 20 and the superimposed speed from the input unit 15. The input unit 15 is preferably reused by the regulating system 1, according to the prior art.

[0048] When converting the control section 1 according to the state of the art ( Figure 1 ) to the regulating section 1 according to the invention ( Figure 2Preferably, at least one of the drive elements 11, 12 and / or the output elements 13 of the differential gear 10 is reused as a transmission element 22 in the regulating motor 17. The transmission element 22 translates the rotational speed of the regulating motor 17 so that the input roller assembly 6 and the intermediate roller assembly 6' are driven at the regulating speed. The regulating speed of the input roller assembly 6 and the intermediate roller assembly 6' can also differ from each other in the embodiment shown in Figure 2. In the present embodiment, the second drive element 12 of the differential gear 10 has been reused as the transmission element 22 of the regulating motor 17. By reusing the second drive element 12 as the transmission element 22 of the regulating motor 17, the permanent transmission ratios used in the regulating section 1 with differential gear 10 and superimposed motor 14 (according to Figure 1) can be very easily adapted to the control section 1 with independent control motor 17.

[0049] The present invention is not limited to the embodiments shown and described. Modifications within the scope of the claims are also possible. Reference symbol list

[0050] 1 Control section 2 Fiber belt 3 Pair of guide rollers 4 Drafter 6, 6', 6" roller combinations 7 Fiber fleece 8 Drive unit 9 Main motor 10 Differential gear 11 First drive element 12 Second drive element 13 Output element 14 Superimposed motor 15 Setpoint unit 16 Brake 17 Control motor 18 Electrical signal 19 Speed ​​sensor 20 Transmission unit 21 Control unit 22 Transmission element

Claims

1. An autoleveller draw frame (1) having a drafting system (4), which includes multiple roller combinations (6, 6', 6") situated one behind the other for drafting a fibrous web (7) to be processed, and having a drive unit (8) for driving the multiple roller combinations (6, 6', 6"), the drive unit (8) including: - a main motor (9) for the speed-constant driving of at least one first roller combination (6") at a main rotational speed, and - a regulating motor (17) for regulating the rotational speed of at least one second roller combination (6, 6'), wherein, due to the regulation, the rotational speed of the second roller combination (6, 6') is changeable from a basic rotational speed, which depends on the main rotational speed, into an autolevelling speed, which is independent of the main rotational speed, and, in this way, the draft of the fibrous web (7) is adjustable, wherein the regulating motor (17) is drive-independent of the main motor (9) and drives the second roller combination (6, 6') independently of the main motor (9) at the autolevelling speed on the basis of an electrical signal (18), which depends on the main rotational speed characterized in that the drive unit (8) includes a speed sensor (19) for detecting the rotational speed of the at least one first roller combination (6") and / or of the main motor (9) and at least one transmission unit (20) for transforming the rotational speed detected by the speed sensor (19) into the basic rotational speed of the second roller combination (6, 6').

2. The autoleveller draw frame (1) of one of the preceding claims, characterized in that the autoleveller draw frame (1) includes a pair of scanning rollers (3) for detecting the thickness of at least one sliver (2) entering the drafting system (4).

3. The autoleveller draw frame (1) of claim 2, characterized in that the autoleveller draw frame (1) includes a specification unit (15), which is electrically operatively connected to the pair of scanning rollers (3) and specifies a superimposition speed and / or determines a superimposition speed from the thickness of the at least one sliver (2).

4. The autoleveller draw frame (1) of one of the preceding claims, characterized in that the drive unit (8) includes a control unit (21) for calculating the autolevelling speed and / or for controlling the regulating motor (17).

5. The autoleveller draw frame (1) of one of the preceding claims, characterized in that the control unit (21) is electrically operatively connected to the specification unit (15), the transmission unit (20) and / or the regulating motor (17) such that the autolevelling speed is calculated from the superimposition speed and the basic rotational speed and / or is transmitted to the regulating motor (17) as an electrical signal.

6. The autoleveller draw frame (1) of one of the preceding claims, characterized in that the main motor (9) is formed as an induction motor and / or the regulating motor (17) is formed as a reluctance motor.

7. A method for operating an autoleveller draw frame (1), in which a fibrous web (7) to be processed is drafted by a drafting system (4), which includes multiple roller combinations (6, 6', 6") situated one behind the other, and the multiple roller combinations (6, 6', 6") are driven by a drive unit (8), wherein - a main motor (9) of the drive unit (8) drives at least one first roller combination (6") at a constant-speed main rotational speed, and - a regulating motor (17) of the drive unit (8) regulates the rotational speed of at least one second roller combination (6, 6'), wherein, due to the regulation, the rotational speed of the second roller combination (6, 6') is changed from a basic rotational speed, which depends on the main rotational speed, into an autolevelling speed, which is independent of the main rotational speed, and, in this way, the draft of the fibrous web (7) is adjusted, wherein the regulating motor (17) drives the second roller combination (6, 6') drive-independently of the main motor (9) at the autolevelling speed on the basis of an electrical signal (18), which depends on the main rotational speed characterized in that the autoleveller draw frame (1) is designed according to one of claims 1 through 6.

8. A method for converting an autoleveller draw frame (1) having a drafting system (4), which includes multiple roller combinations (6, 6', 6") situated one behind the other for drafting a fibrous web (7) to be processed, and having a drive unit (8) for driving the multiple roller combinations (6, 6', 6"), the drive unit (8) including: - a main motor (9) for the speed-constant driving of at least one first roller combination (6") at a main rotational speed, - a differential gear (10) for transmitting the rotational speed of the main motor (9) to at least one second roller combination (6, 6') such that a basic rotational speed of the second roller combination (6, 6') depends on the main rotational speed of the first roller combination (6"), and - a superimposition motor (14) for superimposing a superimposition speed on the basic rotational speed by means of the differential gear (10) such that, due to the superimposition, the rotational speed of the at least one second roller combination (6, 6') is changeable from the basic rotational speed into an autolevelling speed and, in this way, the draft of the fibrous web (7) is adjustable, characterized in that the differential gear (10) is removed from the drive unit (8) and the superimposition motor (14) is replaced by a regulating motor (17), which is drive-independent of the main motor (9), wherein the regulating motor (17), after installation into the autoleveller draw frame (1), drives the second roller combination (6, 6') independently of the main motor (9) at the regulating speed on the basis of an electrical signal (18), which depends on the main rotational speed and wherein after converting the autoleveller draw frame (1) is formed according to one of the claims 1 to 6.

9. The method for converting an autoleveller draw frame (1) of the preceding claim, characterized in that at least one drive element (11, 12) and / or output element (13) of the differential gear (10) is reused as a transmission element (22) of the regulating motor (17).

10. The method for converting an autoleveller draw frame (1) of claim 8 or 9, characterized in that a mechanical or electromagnetic brake (16) of the drive unit (8) is removed.

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