EP2847114B1 - Installation having a shaft to be driven, and method for operating an installation - Google Patents

Description

The invention relates to a system with a shaft to be driven and a method for operating a system.

It is well known that in drives drives drive a shaft.

From the EP 2 184 243 A2 a method for winding material webs and an apparatus for carrying out the method is known.

From the US 2012/097786 A1 For example, a device for reducing the rate of tissue transport is known, this rate of delivery being induced by changes in the geometry of a roller.

The invention is therefore the object of developing a system with a driven shaft, the driving should be able to be improved.

According to the invention the object is achieved in the system with a driven shaft according to the features specified in claim 1 and in the method according to the features indicated in claim 12.

Important features of the invention in the system that
the system is provided with a shaft to be driven,
wherein at least a first and a second gear motor drive the shaft,
wherein a torque caused by a tensile force acts on the shaft, the tensile force being generated by a device,
wherein the torque generated by the first gear motor acts against the torque caused by the tensile force and that acts on the torque generated by the second gear motor in the direction of the torque caused by the tensile force.
The advantage here is that a high setting range, so a wider range of adjustable torque, the shaft driving device, ie the two geared motors, can be achieved. Thus, by means of the second geared motor, the torque of the first geared motor generated when the current is not energized can also be compensated. In this way, the adjustment range is expandable to almost zero.

In an advantageous embodiment, the output shaft of the first and the output shaft of the second geared motor rotatably connected to the shaft,
in particular, wherein the two output shafts are each designed as hollow shafts and are respectively attached to the shaft. The advantage here is that the two output shafts can be arranged one behind the other, ie in the direction of the shaft axis, on the solid shaft.
In an advantageous embodiment, the first and the second geared motor each have a motor-driven or regenerative driven by an electric motor gear, each electric motor is fed in each case by a respective inverter. The advantage here is that although the transmission generates a torque caused by bearing losses, Getriebeölplantschverluste and further friction losses, in particular the teeth, when non-energizing, but that the second gear motor is able to compensate for this torque. In addition, the second gear motor can also compensate for the speed-dependent intrinsic resistance of the first geared motor.
In an advantageous embodiment, at least four times or at least ten times greater torque can be generated by means of the first geared motor than by means of the second geared motor
and or
essentially the first geared motor defines the upper limit of the torque which can be generated by the gearmotors and which can be introduced into the shaft. It is advantageous
that the second gear motor must have only a small size and thus is inexpensive. Although two gear motors are arranged on the shaft, however, only the first is used to generate the actual drive torque. The second is only the compensation of the torque losses of the transmission of the first geared motor.

In an advantageous embodiment, the torque generated by the second geared motor and directed to the shaft substantially equal to that amount of torque which is generated by the transmission of the first geared motor when the first geared motor is de-energized. The advantage here is that only the first gear motor is necessary for the essential drive torque and the second is required only for the compensation.

In an advantageous embodiment, a sensor for determining the tensile force is arranged in the system, wherein the detected actual value of the tensile force is fed to a controller of the inverter supplying the first geared motor. The advantage here is that the second geared motor is operated as a relief machine. In this case, the second geared motor adjusts to a torque value determined according to a characteristic curve M (n), which is assigned to the actual rotational speed. The first geared motor is regulated to the nominal tension.

In an advantageous embodiment, the controller of the converter supplying the first geared motor is supplied with a setpoint value for the tractive force. The advantage here is that on a target value of traction is hinregelbar.

In an advantageous embodiment, the controller of the inverter feeding the second gear motor is supplied with a speed actual value, from which a torque setpoint to be reached is determined according to a characteristic curve. The characteristic describes the speed-dependent inherent inhibition of the first drive or compensates over. The advantage here is that the losses of the transmission of the first gear motor can be compensated or overcompensated and thus an extended range of the drive assembly can be achieved.

Important features in the method for operating a system are that a radius of a winding roll is determined and a tensile force is determined,
the speed of the winding roll being determined
wherein the control deviation of the detected tensile force is determined to a predetermined desired value of tensile force and is converted by means of the determined radius into a torque value to which the torque generated by a first geared motor is adjusted,
the second geared motor generates a torque, which is controlled to a torque setpoint, which is determined as a function of the detected speed of the winding roll and / or the shaft according to a characteristic, in particular wherein the characteristic describes the speed-dependent intrinsic resistance of the transmission of the first geared motor or overcompensating describes.

The advantage here is that the second drive makes the self-locking of the first drive compensated or makes overcompensated. Thus, the adjustment range of the first drive is increased and the control properties improved. If the first drive is less powerful then a very large adjustment range can be realized.

If the first drive is selected to be less powerful than the second drive, a refined and thus improved controllability within the setting range can be achieved as a result of the more refined current resolution of the less powerful drive. However, then the fine adjustment range is determined only by the less powerful drive.

Further advantages emerge from the subclaims. The invention is not limited to the combination of features of the claims. For the skilled person, further meaningful combination possibilities of claims and / or individual claim features and / or features of the description and / or figures, in particular from the task and / or posing by comparison with the prior art task arise.

• In der Figur 1 ist eine schematische Ansicht der erfindungsgemäßen Anlage gezeigt.
• In der Figur 2 ist ein Funktionsschema der Umrichter der Antriebe, also eines ersten und eines zweiten Getriebemotors, gezeigt.
• In der Figur 3 ist die Vergrößerung des Drehmoment-Stellbereichs durch das Hinzufügen eines zweiten Getriebemotors zur Antriebsanordnung gezeigt.
• In der Figur 4 ist die schematische Ansicht der erfindungsgemäßen Anlage in Schrägansicht gezeigt, wobei die Sensorrolle zur Bestimmung der Zugkraft F nicht dargestellt ist.

The invention will now be explained in more detail with reference to figures:

• In the FIG. 1 is a schematic view of the system according to the invention shown.
• In the FIG. 2 is a functional diagram of the inverter of the drives, so a first and a second geared motor, shown.
• In the FIG. 3 the enlargement of the torque-adjusting range is shown by the addition of a second geared motor to the drive assembly.
• In the FIG. 4 the schematic view of the system according to the invention is shown in an oblique view, wherein the sensor roller for determining the tensile force F is not shown.

Like in the FIG. 1 shown, a winding roller 2 is rotatably connected on a shaft 1, on which a winding material, such as paper or fabric, can be wound.

In this case, the winding material is unwound with a force F, ie an actual value of force, wherein a device not shown causes this tensile force F.

By means of a deflection roller, a sensor S can be provided which detects the actual value F_act of the tensile force F.

To regulate the tensile force to a desired value F_Soll out the shaft 1 is connected to a first geared motor, wherein the geared motor counteracts the tensile force F. For this purpose, the geared motor generates a torque M which is between a maximum value and a minimum value. The maximum value M_max of the torque M is determined by the size and construction of the geared motor. The minimum value M_min of the torque M is the value that occurs when the motor is not energized. Here, the transmission is driven by the winding roller 2 and the motor acts only by means of its moment of inertia, if no overcompensation by the second gear motor takes place.

The acting on the winding roll torque M is the radius, ie half the diameter of the winding roll 2 dependent. Where M = F x R

According to the invention, the shaft 1 of the winding roll 2, as well as in FIG. 4 shown not only connected to the output shaft of the first geared motor 41 but also to the output shaft of a second geared motor 42. Thus, both torques generated by the geared motors (41, 42) act on the shaft 1 of the winding roller 2.

In this way, it is possible that the second geared motor 42 counteracts the torque M_min, that is to say the self-locking of the first geared motor 41, generated by its gearbox when the first geared motor 41 is de-energized. Thus, the second geared motor 42 increases with its torque generated by it on the tensile force. The torque generated by the first gear motor 41 has a degrading effect on the tensile force F, since it counteracts it. For the force F iast caused by the device, not shown. The torque generated by the second gear motor 42 has an increasing effect on the shaft, in particular tensile force F, since it acts in the direction of the force direction generated by the device, not shown. The sum of the forces generated by the two gear motors (41, 42) and the force generated by the device, not shown, is zero in stationary operation.

The size of the second geared motor 42 is smaller executable than the size of the first geared motor, since the second geared motor must apply only the amount M_min of the first geared motor. The adjustment range of the entire drive is thus traversed by the converter of the first geared motor 41. The second geared motor 42 compensates only the self-locking.

In this way, the adjustment range of the first geared motor 41, which would only be present between M_min and M_max, can be extended by means of the second geared motor. In this case, as a lower limit even almost a vanishing torque allows.

As a motor preferably a synchronous motor or an asynchronous motor is used and as a gear transmission with a spur gear, with a planetary gear or with a non-self-locking angle gear.

As in FIG. 2 1, the actual value F_act of the pulling force determined by the sensor is fed to the converter 21 of the first geared motor 41, which has a controller to which this actual value F_act is supplied. In addition, the controller is also a setpoint F_Soll fed, which corresponds to the desired draft amount. The control deviation is fed to a linear regulator and converted by means of multiplication with the radius of the winding roll 2 detected by a sensor or determined by another method into a torque value M1_soll to which the first converter 21 controls.
The inverter 22, which feeds the second geared motor 42, receives the actual value n_act of the rotational speed of the shaft and determines according to a characteristic curve M (n) a desired torque value M2_setpoint, which is thus a function of the rotational speed n. The characteristic M (n) describes the speed-dependent self-locking of the transmission of the first geared motor. Here, the intrinsic resistance caused by the Ölplantschverluste, rolling friction of the rolling elements of the bearing and the friction losses, in particular the meshing teeth.

The first inverter 21 feeds the electric motor of the first geared motor 41, and the second inverter 22 feeds the electric motor of the second geared motor 42.
The controller of the first inverter 21 receives as a setpoint the setpoint F_Soll the tensile force, which is to prevail on the winding roll 2. From the control deviation, ie deviation of the actual value F_ist from the setpoint F_Soll, a manipulated variable is determined, wherein the controller is in the simplest case a linear controller, such as PID controller. Alternatively, however, a simple proportional controller or a PI controller can be used. As in FIG. 2 4, the manipulated variable is a torque value which is generated by means of said multiplication with the radius of the winding roll 2 from the electric motor with gearbox fed by the first converter 21. The setting range is between M_min and M_max.
The controller of the second converter 22 receives as an actual value the detected at the shaft speed from which by means of the speed-dependent intrinsic braking characteristic M (n) of the torque setpoint M2_Soll is formed, to which the torque of the second geared motor is controlled. The second geared motor 42 thus compensates the inherent inhibition of the first geared motor 41.

Thus, the target value F_Soll is reached in tensile force, which is to prevail on the winding roll 2.

Depending on the radius R of the winding roll 2, the torque M corresponds to a tensile force $$\mathrm{F}=\mathrm{M}\times \mathrm{R},$$

Preferably, the maximum torque that can be generated by the drives is M_max and the minimum torque that can be generated by the drives is M_min.

The lower, can be generated by the geared motor torque limit M0 is almost zero, since the second gear motor, the self-escapement, ie the torque generated by the gearbox of the first gear motor with no-current first gear motor compensated, the speed is predetermined by the shaft 1 and the intrinsic resistance according to speed is dependent.

As in FIG. 4 The torque M1 is introduced by the first geared motor 41 and the torque M2 is introduced into the shaft 1 by the second geared motor 42. The opposing force F generated by the geared motors against the tensile forces is indicated by an arrow and acts on the radius R of the winding roll 2.

FIG. 5 shows the speed-dependent intrinsic resistance, ie the speed-dependent torque M (n), which occurs at Nichtbestromen of the first geared motor and as a characteristic M (n) the second gear motor for compensation at least predetermined. However, overcompensation is also possible. It is advantageous in the overcompensation that not the complicated speed-dependent curve must be specified as a characteristic but a simpler course, such as a constant course. Due to the compensation or overcompensation, the range 52 alone is effective as the setting range of the entire drive, which comprises the first and the second gear motor; Thus, the area 53 is ineffective as a parking area, since it is compensated

In further embodiments of the invention, the system is an unwinder or rewinder. The setting range of the two geared motors, that is (R_max x F_max) / (R_min x F_min), is greater than 30 by means of the invention, where R_max is the maximum radius of the winding roll, where R_min is the minimum radius of the winding roll, where F_max is the maximum tensile force occurring and F_min is the minimum pulling force.

In further embodiments of the invention, the controller of the two inverters are reversed, whereby the inverter of the more powerful first geared motor gets the actual speed n_ist supplied and determined according to a characteristic M (n) the torque setpoint M_Soll and passes by means of the geared motor to the shaft. The controller of the converter of the second geared motor receives the actual force F_act and the determined or detected radius of the winding roller 2, so that it determines a control value from the comparison with the desired force F_setpoint and thus operates the second controller in such a way that the actual force points to the desired force is regulated.

In further embodiments of the invention, the radius of the winding roll is not detected directly by a sensor but determined by means of the detected unwinding or winding speed of the winding material and the detected rotational speed of the shaft by the quotient of the speeds is formed.

In further embodiments of the invention, a transmission is arranged between the shaft and the winding roller, so that the rotational speeds differ by a factor.

In further embodiments of the invention, the controllers of the inverter are not in the inverters (21, 22) but arranged in a higher-level control, which is connected by means of a data bus with the inverters (21, 22).

In further embodiments of the invention, in a first preliminary step, for example, at startup, the characteristic of the intrinsic resistance of one of the two gear motors is determined by this is operated without power at several speeds, preferably decoupled or empty winding roller, and occurring at the other gear motor torque to overcome the intrinsic resistance of the first-mentioned geared motor is determined. In order to neutralize measurement errors and / or to achieve the overcompensation then becomes Added safety margin to the torque determined at each speed and deposited these thus determined speed-torque value pairs as discretely represented characteristic. Intermediate values can be easily determined by interpolation, in particular linear interpolation.

LIST OF REFERENCE NUMBERS

• 1 wave
• 2 winding roll
• 41 first geared motor
• 42 second geared motor
• S sensor
• F tensile force, which is effective for unwinding the winding roll
• F_setpoint of the tensile force
• F_act Actual value of the tensile force
• F_soll, offset offset value of the de-energized first geared motor
• R Radius of the winding roll, depending on the wound quantity
• M torque
• M1 torque generated by the first geared motor
• M2 torque generated by the second geared motor
• M_max Maximum value of the torque that can be generated by the drives
• M_min minimum value of the torque that can be generated by the first geared motor
• M0 lower, can be generated by the gear motor torque limit

Claims (13)

1. An installation with a shaft (1) which is to be driven,
   wherein at least a first and a second geared motor (41, 42) provide drive,
   wherein a torque (M) brought about by a tractive force acts on the shaft (1),
   the tractive force being generated by a device,
   characterised in that
   the torque (M1) generated by the first geared motor (41) acts counter to the torque brought about by the tractive force and the torque (M2) generated by the second geared motor (42) acts in the direction of the torque brought about by the tractive force,

   - with the torque (M2) generated by the second geared motor (42) and passed on to the shaft (1) being substantially equal amount-wise to that torque amount which is generated by the gear mechanism of the first geared motor (41) if the first geared motor (41) is in a de-energised state,

   - or with the second geared motor (42) generating a torque (M2) which is adjusted to a desired torque value which is determined as a function of the detected speed of rotation of the winding roll (2) and/or of the shaft (1) in accordance with a characteristic curve, in particular with the characteristic curve describing or describing in over-compensating manner the inherent inhibition of the gear mechanism of the first geared motor (41) which is dependent on the speed of rotation,

   - or with a desired value being supplied to the controller of the converter which feeds the second geared motor (42), which value corresponds to the torque (M1) generated by the gear mechanism of the first geared motor (41) when the first geared motor (41) is de-energised.
2. An installation according to Claim 1,
   characterised in that
   the output shaft of the first and the output shaft of the second geared motor (42) are connected to the shaft (1) in rotation-resistant manner,
   in particular with the two output shafts being embodied in each case as hollow shafts and being placed in each case on the shaft (1).
3. An installation according to at least one of the preceding claims,
   characterised in that
   the first and the second geared motor (41, 42) in each case have a gear mechanism which can be driven as a motor or as a generator by an electric motor, each electric motor being fed in each case by a respective converter.
4. An installation according to at least one of the preceding claims,
   characterised in that
   a torque (M1) which is at least four times or at least ten times greater than that which can be generated by means of the second geared motor (42) can be generated by means of the first geared motor (41)
   and/or in that
   substantially the first geared motor (41) defines the upper control limit of the torque which can be generated by the geared motors (41, 42) and which can be introduced into the shaft (1).
5. An installation according to at least one of the preceding claims,
   characterised in that
   a sensor (S) for detecting the radius of the winding roll (2) is provided
   or in that
   the radius of the winding roll (2) is determined from the detected speed of rotation of the shaft (1) and the detected peripheral speed of the winding roll (2) or from the speed of the unwound or wound-up material for winding.
6. An installation according to at least one of the preceding claims,
   characterised in that
   a sensor (S) for determining the tractive force is arranged in the installation,
   the detected actual value of the tractive force being supplied to a controller of the converter which feeds the first geared motor (41).
7. An installation according to at least one of the preceding claims,
   characterised in that
   a desired value for the tractive force is supplied to the controller of the converter which feeds the first geared motor (41),
   the deviation being converted by means of multiplication by the radius of the winding roll (2) into a torque value M1_soll to which the torque (M1) generated by the first geared motor (41) is adjusted.
8. An installation according to at least one of the preceding claims,
   characterised in that
   the second geared motor (42) generates a torque (M2) which overcomes the inherent inhibition of the first geared motor (41).
9. An installation according to at least one of the preceding claims,
   characterised in that
   the controller for the first converter and the controller for the second converter are interchanged.
10. An installation according to at least one of the preceding claims,
    characterised in that
    the installation is an unwinder or a winder
    and/or in that
    a winding roll (2) is arranged on the shaft (1).
11. An installation according to at least one of the preceding claims,
    characterised in that
    the range of control of the two geared motors (41, 42), i.e. (R_max x F_max) / (R_min x F_min), is greater than 30,
    R_max being the maximum radius of the winding roll (2),
    R_min being the minimum radius of the winding roll (2),
    F_max being the maximum tractive force occurring and F_min being the minimum tractive force occurring.
12. A method for operating an installation according to at least one of the preceding claims,
    characterised in that
    a radius of a winding roll (2) is determined and a tractive force is determined,
    with the speed of rotation of the winding roll (2) being determined,
    with the deviation of the detected tractive force from a specified desired value of tractive force being determined and being converted by means of the radius which is determined into a torque value to which the torque (M1) generated by a first geared motor (41) is adjusted,
    the second geared motor (42) generates a torque (M2) which is adjusted to a desired torque value which is determined as a function of the detected speed of rotation of the winding roll (2) and/or of the shaft (1) in accordance with a characteristic curve, in particular with the characteristic curve describing or describing in over-compensating manner the inherent inhibition of the gear mechanism of the first geared motor (41) which is dependent on the speed of rotation.
13. A method according to Claim 12,
    characterised in that
    in a preceding method step the characteristic curve is determined in that the first geared motor (41) is operated in a de-energised state and the torque (M2) occurring at the second geared motor (42) is determined in order to overcome the inherent inhibition of the first geared motor (41),
    in particular with a safety allowance being factored in for determining the characteristic curve from the detected values.

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