Textile machine having device for monitoring tension in belt

Abstract

The invention relates to a textile machine (1) having a drive unit (10) and at least one rotating element (11), in which a belt (12) is tensioned between the drive unit (10) and the rotating element (11), and in which the belt (12) is guided by means of at least one belt pulley (13) mounted on a shaft (14). According to the invention, an electrical force measuring device (15) is designed, by means of which a force acting on the shaft (14) by the pulley (13) can be measured by means of a measuring technique.

Description

Technical Field

[0001] The invention relates to a textile machine having a drive unit and at least one rotating element, wherein a belt is tensioned between the drive unit and the rotating element and wherein the belt is guided via at least one pulley mounted on a shaft. Background Art

[0002] DE 20220531 U1 discloses a textile machine, which is designed as a draw frame and has a drive unit and at least one rotating element, wherein the rotating element forms, for example, the bottom roller of the draw frame, wherein a belt is tensioned between the drive unit and the rotating element, and wherein the belt is guided via at least one pulley mounted on a shaft. This example shows a plurality of pulleys designed in the form of rollers, which are rotatably mounted on the shafts and around which the belt is guided.

[0003] The drive unit is used to drive a rotating element, for example the top roller and / or the bottom roller of a drafting mechanism of a draw frame, and the driving force is transmitted from the drive unit to the rotating element by means of a belt, which is designed, for example, as a toothed belt. In order to reliably transmit the force via the belt, the belt must be designed with a certain pretension. In this case, the tension of the belt also depends on the force to be transmitted, wherein the function to be performed by the rotating element in the textile machine (e.g. a draw frame) must also be taken into account in order to determine the tension of the belt.

[0004] For example, it is possible to determine the tension of the belt by measuring the vibration frequency of the belt run when the textile machine is stationary. To this end, the belt is manually set into free vibration by impact, and the vibration is measured acoustically or optically with the aid of appropriate instruments. The belt tension can then be adjusted to the desired value by means of a belt tensioning device. However, during the continued operation of the textile machine, the tension in the belt decreases again in this case, in particular because the elastic properties of the belt change and it is usually stretched.

[0005] DE 21 31 816 A1 discloses a device for measuring belt tension, which uses a measuring rod which, in the stationary state, presses against the free run of the belt, thereby measuring the extent to which the belt is compressed at a specific pressure and thus being able to determine the belt tension.

[0006] DE 10 2008 002 304 B4 shows another measuring device for measuring the belt tension in a belt run, for which a punch is provided which moves until a predeterminable differential force is generated on the belt run and the punch force is measured on the belt run after a predetermined further displacement, from which the belt tension of the belt run can be determined. Even in the case of such a mechanical measuring device for determining the belt tension, the belt and the textile machine in which the belt is installed must be stopped. This results in a reduction in the output of the textile machine and the measurement must be performed manually by trained personnel using a handheld instrument. Most importantly, changes in the belt tension during, for example, the continuous operation of the textile machine cannot be continuously detected with such a mechanical measuring method. As a result, corrective measures cannot be taken in time to prevent further damage. For example, in order to achieve a good control quality, the control drive of a draw frame depends on an optimal belt tension. Otherwise, the required quality of the product of the textile machine, for example a fiber strip, cannot be maintained. Summary of the invention

[0007] The object of the present invention is to improve a textile machine according to the preamble of claim 1 , wherein the improvement in particular allows a continuous determination and monitoring of the belt tension of a belt between a drive unit and a rotating element with the lowest possible effort.

[0008] This object is achieved by a textile machine according to the preamble of claim 1 together with the characterizing features. Advantageous developments of the invention are specified in the dependent claims.

[0009] In order to achieve this object, the invention provides for the provision of an electrical force measuring device, by means of which the force acting on the shaft by the pulley of the guide belt can be detected by measurement.

[0010] The core idea of ​​the invention is to dispense with conventional mechanical tactile measuring devices for measuring the belt tension of a belt between a drive unit and a rotating element, and to infer the belt tension from the force to be measured between a pulley and a shaft using measurable electrical variables. It is therefore sufficient to design an electrical force measuring device in such a way that it measures only the force detected by measurement between the pulley guiding the belt and the shaft rotatably receiving the pulley. The belt also exerts a certain force on the pulley and therefore also on the shaft when the textile machine is not running, and the detectable force is primarily determined by the basic force of the belt and the operating force used to increase the basic force of the belt on the pulley. As a result, the belt tension of a belt between a drive unit and a rotating element can be continuously determined and monitored with the lowest possible effort.

[0011] Such a measuring device is possible when the belt drive consists only of the actual belt and pulleys, which are present on the drive unit, the intermediate pulley or the driven pulley, for example, directly connected to the rotating element. The shaft here can be a stationary shaft on which the pulley performs a rotational movement, or a pulley rotating together with the shaft, which is correspondingly supported in the textile machine. In this case, most pulleys are fastened to shafts, which in turn are supported in the machine by means of rotating bearings. In most cases, especially in textile machines, these bearings are designed as rolling bearings, and the forces to be transmitted by the belt and the tensioning forces of the belt are supported in the machine via rolling bearings.

[0012] By measuring the force on the shaft according to the invention, the current belt tension can be obtained. This measurement can be carried out during continuous operation, thereby overcoming the above-mentioned disadvantages of the prior art.

[0013] Advantageously, the force measuring device is at least partially arranged between the pulley and the shaft. The force measuring device is particularly arranged such that the force between the pulley and the shaft can be measured indirectly, for example via a lubrication gap of a bearing arrangement between the pulley and the shaft.

[0014] In particular, a rolling bearing is provided, by which the pulley is rotatably supported on the shaft, wherein the force measuring device is designed to be connected to the rolling bearing. The force measuring device has in particular an electrical measuring unit, to which the pulley and the shaft, but in particular the rolling bearing, are connected. If the pulley rotates on the shaft, the lubrication gap generated in the rolling bearing can be used as a measured variable, wherein the lubrication gap thickness is detected by means of the electrical measuring unit and the force between the pulley and the shaft can be derived from the measured variable.

[0015] Particularly advantageously, a belt tensioning device can be provided, wherein the belt pulley is designed to be connected to the belt tensioning device and can be adjusted relative to the belt by means of the belt tensioning device in order to change the belt tensioning. The belt tensioning device is particularly designed such that the shaft that receives the belt pulley can be moved relative to the belt, for example, by means of a slide or a similarly acting device, so that the belt pulley of the belt tensioning device tensions the belt. The belt pulley received on the shaft, together with the belt tensioning device and in particular the rolling bearing designed therefor, is particularly suitable for designing the electrical force measuring device according to the invention.

[0016] The rolling bearing has in particular an inner ring and an outer ring, wherein rolling elements are arranged between the inner ring and the outer ring, and wherein the force measuring device is designed to apply a voltage between the inner ring and the outer ring. If the outer ring rotates relative to the inner ring, a lubricating film is generated at the contact points or contact lines of the rolling elements with the inner ring or the outer ring by the introduced lubricant, which lubricating film produces a geometric separation of the rolling elements from the rings.

[0017] If the inner ring is mounted stationary on the shaft, the inner ring is insulated from the shaft and is in electrical contact with the force measuring device. If the outer ring of the rolling bearing rotates, the electrical contacts can be in contact with the outer ring by means of sliding contact collectors or using capacitive couplings.

[0018] If an electrical potential is now applied between the contacts on the inner ring and the outer ring of the rolling bearing, the forces acting on the rolling bearing, in particular radial forces, can be derived from the change in the thickness of the lubricating film. Alternatively, the rolling bearing can also be integrated into a resonant circuit, wherein the signal assignments to the components of the rolling bearing and in particular the arrangement of the pulley on the shaft are determined by means of an electrical measuring unit of the force measuring device. If the inner ring and the outer ring are regarded as capacitor plates, between which the lubricant in the lubrication gap forms a dielectric, the rolling bearing can act as a capacitor in a resonant circuit.

[0019] Furthermore, it is advantageous if a temperature measuring device is provided and is designed to detect the temperature of the rolling bearing or at least the temperature of a component of the rolling bearing by measuring technology. The temperature measuring device can in particular comprise a thermocouple which is arranged in or on the rolling bearing and measures the temperature of the rolling bearing. The temperature measuring device is in particular connected to the force measuring device and preferably to an electrical measuring unit of the force measuring device.

[0020] Furthermore, a rotational speed measuring device is provided, by means of which the rotational speed of a pulley on the shaft can be detected at least indirectly. It is sufficient for the rotational speed of a rotating element of the textile machine to be known, which is coupled to a pulley arranged on the shaft via a belt, wherein a force measuring device is provided between the pulley and the shaft. If the rotational speed of the drive unit or the rotational speed of the rotating element is known, the rotational speed of the pulley on the shaft and the rotational speed of the outer ring of the rolling bearing relative to the inner ring can be determined. The rotational speed detected by the rotational speed measuring device is also recorded by the force measuring device and in particular by the electrical measuring unit of the force measuring device.

[0021] If the electrical force measuring device is provided on the textile machine, it can initially be linked to another force measuring device that acts, for example, mechanically or electrically, for example on a belt tensioning device for determining the belt tension. Then, according to the invention, the electrical force measuring device can be linked, in particular on the textile machine and on the operating range of the belt, in which the belt tension is measured and in particular monitored.

[0022] The textile machine is in particular configured as a draw frame for spinning preparation. The belt can be a component of the drafting mechanism and, for example, drives the top roller and / or the bottom roller.

[0023] The force measuring device has in particular an electrical measuring unit, wherein the textile machine also has a control device, to which the electrical measuring unit is connected, so that the force value of the belt is output by the force measuring device to the control device, monitored by the control device and displayed, for example, to an operator.

[0024] Furthermore, a measuring device for measuring the properties of a fiber strand processed or handled by means of a textile machine, in particular a measuring device for measuring the mass per unit length of the fiber strand, can be provided, wherein the control device of the textile machine is designed to correlate or link the measured values ​​of the electrical measuring unit with the measured values ​​of the measuring device for measuring the properties of the fiber strand. Textile machines, in particular textile machines in spinning preparation, usually process and handle fiber bundles or output fiber bundles as fiber products, the properties of which can be monitored. Thus, the drafting of the fiber bundles transported from the drafting mechanism of the drawing machine can be monitored regularly or continuously in a known manner, which is also achieved at least indirectly by means of the control device of the textile machine. Now, according to the invention, if the control device is provided with values ​​for the belt tension of the belt in the drafting mechanism, then the values ​​obtained by monitoring the fiber bundle, i.e. the drafting values ​​(measured at a specific length weight of the fiber bundle), can be linked to the values ​​for the belt tension by means of the control device, which can, for example, enable significantly simpler and predictive guidance of the textile machine during operation, since the causes of deviations of the measured values, for example, regarding the quality of the fiber product, can be simplified. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Further measures that improve the invention are explained in more detail below together with the description of preferred exemplary embodiments of the invention with reference to the drawings.

[0026] In the figure:

[0027] Figure 1 An example of a textile machine is shown with a draw frame having a drafting mechanism.

[0028] Figure 2 The individual drive trains of the drafting arrangement with the individual components of the transmission are shown, Figure 3 The belt tensioner is shown in a single view, and

[0029] Figure 4 The arrangement of a force measuring device on a rolling bearing which is part of a drive of a drafting arrangement or a belt tensioning device of a draw frame is shown. DETAILED DESCRIPTION

[0030] Figure 1An example of a textile machine 1 is shown with a draw frame 2 having a drafting mechanism 3, and the drafting mechanism 3 has a plurality of rotating elements 11, one of which is shown as a bottom roller, which is driven by a drive unit 10 via a belt 12. The belt 12 is guided via a plurality of pulleys 25, 26, 27, wherein a drive pulley 28 is connected to the drive unit 10, so that the rotating element 11 is driven via the belt 12 by means of the drive pulley 28 driven by the drive unit 10.

[0031] In addition, the belt tensioning device 17 is designed to have a pulley 13, through which the belt 12 is guided, and the pulley 13 is rotatably supported on the shaft 14. The belt tensioning device 17 can displace the shaft 14 and thus the pulley 13, so that the belt 12 can be tensioned by the belt tensioning device 17.

[0032] Figure 2 The drive train of the drafting arrangement is shown with the individual components of the transmission, including the belt 12, the rotatable element 11 (replaced by an associated pulley), further pulleys 25, 26 and 27 and a drive pulley 28 with the drive unit 10. The belt tensioning device 17 is located between the pulleys 25 and 26 and has a tensioning device 29, by means of which the shaft 14 and thus also the pulley 13 can be displaced in the force direction F shown in order to exert a belt tension on the belt 12.

[0033] Figure 3 The belt tensioning device 17 is shown in an enlarged view, wherein the tensioning means 29 is shown as a pressure lever and cooperates with a slide 30 which can be guided in a machine-fixed guide (not shown) in the direction of the arrow so that a tensioning force F can be applied. The shaft 14 is fixedly mounted on the slide 30 and the belt pulley 13 is rotatably mounted on the shaft 14 , about which the belt 12 can be wound.

[0034] The pulley 13 is rotatably arranged on the shaft 14 by means of a rolling bearing 16, wherein the force measuring device 15 is designed to be connected to the rolling bearing 16. The force measuring device 15 has a first electrical contact 31, which is in contact with the inner ring 18 of the rolling bearing 16, wherein the inner ring 18 is supported on the shaft 14, in particular electrically insulated. Another electrical contact 32 of the force measuring device 15 is in contact with the outer ring 19 of the rolling bearing 16 and is designed, for example, as a sliding contact and is therefore electrically connected to the rotating outer ring 19 of the rolling bearing 16. In this case, the electrical measuring unit 23 is preferably also operatively connected to the control device 24 of the textile machine, so that the measured force of the force measuring device 15 is detected by the control device 24 of the textile machine and can be displayed or monitored in particular.

[0035] Figure 4The belt pulley 13 is shown on the shaft 14, and the belt 12 is partially shown around the belt pulley 13. In order to rotatably support the belt pulley 13 on the shaft 14, the rolling bearing 16 is designed with an inner ring 18 and an outer ring 19, and a plurality of rolling bodies 20 are located between the rings 18 and 19.

[0036] There is a lubrication gap 33 between the rolling elements 20 and the inner ring 18 and the outer ring 19, and if an electrical potential is applied between the inner ring 18 and the outer ring 19 of the rolling bearing 16 via the electrical contacts 31 and 32, and the outer ring 19 rotates relative to the inner ring 18, then the solid contact of the rolling elements 20 with the active surfaces in the inner ring 18 and the outer ring 19 is geometrically separated. This geometric separation is achieved by the lubrication gap 33 due to fluid dynamic effects, and if an electrical potential is applied between the inner ring 18 and the outer ring 19 via the electrical contacts 31, 32, then the force between the inner ring 18 and the outer ring 19 can be derived from the thickness of the lubrication gap 33 according to the corresponding relationship. Such a force determination can be achieved, for example, in the electrical measuring unit 23. Then, a value for the tensioning force F can be outputted by the electrical measuring unit 23.

[0037] The invention is not limited to the preferred exemplary embodiments given above in its implementation. Rather, a number of variants are conceivable, which also use the solution described in principle in different types of embodiments. All features and / or advantages, including structural details or spatial arrangements, derived from the claims, the description or the drawings are essential to the invention both per se and in various combinations.

[0038] Reference numerals list

[0039] 1 Textile machinery

[0040] 2 Draw Frame

[0041] 3 Drafting mechanism

[0042] 10 Drivers

[0043] 11 Rotating elements

[0044] 12 Belt

[0045] 13 Pulley

[0046] 14 Axis

[0047] 15 Force measuring device

[0048] 16 Rolling bearings

[0049] 17 Belt tensioner

[0050] 18 Inner Ring

[0051] 19 Outer Ring

[0052] 20 Rolling elements

[0053] 21. Temperature measuring device

[0054] 22 Speed ​​measuring device

[0055] 23 Electrical measurement unit

[0056] 24 Control Devices

[0057] 25 Pulley

[0058] 26 Pulley

[0059] 27 Pulley

[0060] 28 Drive pulley

[0061] 29 Tensioning device

[0062] 30 Sliders

[0063] 31 Electrical contacts

[0064] 32 electrical contacts

[0065] 33 Lubrication clearance

[0066] F Tension

Claims

1. A textile machine (1) comprising a drive unit (10) and at least one rotating element (11), wherein: A belt (12) is tensioned between a drive unit (10) and a rotating element (11), wherein the belt (12) is guided via at least one pulley (13) supported on a shaft (14), characterized in that an electrical force measuring device (15) is provided, by means of which the force acting on the shaft (14) from the pulley (13) can be detected by measurement technology.

2. The textile machine (1) according to claim 1, characterized in that The force measuring device (15) is arranged at least partially between the pulley (13) and the shaft (14).

3. The textile machine (1) according to claim 1 or 2, characterized in that A rolling bearing (16) is provided so that the belt pulley (13) is rotatably supported on the shaft (14) by means of the rolling bearing (16), wherein the force measuring device (15) is designed to be connected to the rolling bearing (16).

4. The textile machine (1) according to any one of claims 1 to 3, characterized in that A belt tensioning device (17) is provided, wherein the belt pulley (13) is designed to be connected to the belt tensioning device (17) and can be adjusted relative to the belt (12) by means of the belt tensioning device (17) in order to change the belt tension.

5. The textile machine (1) according to one of the preceding claims, characterized in that The rolling bearing (16) has an inner ring (18) and an outer ring (19), wherein rolling bodies (20) are arranged between the inner ring (18) and the outer ring (19), and wherein the force measuring device (15) is designed to apply a voltage between the inner ring (18) and the outer ring (19).

6. The textile machine (1) according to one of the preceding claims, characterized in that A temperature measuring device (21) is provided and is designed to detect the temperature of the rolling bearing (16) or at least the temperature of a component of the rolling bearing by means of metrology.

7. The textile machine (1) according to one of the preceding claims, characterized in that A rotational speed measuring device (22) is provided, by means of which the rotational speed of a belt pulley (13) on a shaft (14) can be detected at least indirectly.

8. The textile machine (1) according to one of the preceding claims, characterized in that The textile machine (1) is designed as a draw frame (2) for spinning preparation.

9. The textile machine (1) according to claim 8, characterized in that A belt (12) drives and connects the drive unit (10) of the drawing frame (2) to the bottom roller.

10. The textile machine (1) according to one of the preceding claims, characterized in that The force measuring device (15) has an electrical measuring unit (23), and the textile machine (1) has a control device (24), wherein the electrical measuring unit (23) is operatively connected to the control device (24) and the control device (24) monitors the belt tension by means of the connection to the measuring unit (23).

11. The textile machine (1) according to one of the preceding claims, characterized in that A measuring device is provided for measuring the properties of a fiber strip processed or handled by means of a textile machine (1), in particular a measuring device for measuring the mass per unit length of the fiber strip, wherein a control device (24) of the textile machine (1) is designed to correlate or link the measured values ​​of an electrical measuring unit (23) with the measured values ​​of the measuring device for measuring the properties of the fiber strip.

Images