Textile machine with a device for monitoring the tension in a belt
Patent Information
- Application Number
- EP2023741379
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-08-19
- Filing Date
- 2023-07-11
- Publication Date
- 2025-06-25
AI Technical Summary
Current textile machines require frequent manual shutdowns for mechanical belt tension measurement, leading to production losses and inability to monitor belt tension changes during operation, which can result in consequential damage and quality issues.
An electrical force measuring device is integrated between the pulley and shaft to measure forces acting on the shaft, allowing for continuous monitoring of belt tension without the need for mechanical-tactile devices, enabling real-time belt tension adjustment and maintenance.
This solution allows for permanent and effortless monitoring of belt tension between the drive unit and rotating element, preventing damage and maintaining product quality by enabling continuous operation and real-time corrective measures.
Smart Images
Figure 1.1
Abstract
Description
[0001] Internal file number P229910WO1 Title: Textile machine with a device for monitoring the tension in a belt Description The invention relates to a textile machine, comprising 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 over at least one pulley which is mounted on a shaft. From DE 202 20 531 U1 a textile machine, designed as a draw frame, is known, comprising a drive unit and at least one rotating element, wherein the rotating elements form, for example, the bottom rollers of the draw frame, wherein a belt is tensioned between the drive unit and the rotating element, and wherein the belt is guided over at least one pulley which is mounted on a shaft.The example shows several pulleys, designed in the form of rollers that are rotatably mounted on shafts and around which the belt is guided. The drive unit is used to drive the rotating elements, for example the upper rollers and / or lower rollers of the draw frame's drafting system, and the drive force is transferred from the drive unit to the rotating elements by means of the belt, which is designed, for example, as a toothed belt. In order to reliably transmit the force via the belt, the belt must be set up with a defined pretension. The tension of the belt depends, among other things, on the force to be transmitted, whereby the function to be fulfilled by the rotating element in the textile machine, for example the draw frame, must also be taken into account when determining the tension of the belt.For example, it is possible to determine the belt tension when the textile machine is at a standstill by measuring the oscillation frequency of one belt strand. To do this, the belt is manually initiated into free oscillation by a push, and this is measured acoustically or visually using a suitable device. The belt tension can then be adjusted to the desired value using a belt tensioning device. However, over the operating life of the textile machine, the tension in the belt decreases again, particularly because the belt's elastic properties change and it usually elongates.Internal file number P229910WO1 DE 2131816 A1 discloses a device for measuring belt tension. This device uses a feeler pin which, when at rest, is pressed onto a free belt strand to measure how strongly the belt bends under a defined pressure force, after which the belt tension can be determined. DE 10 2008 002 304 B4 shows a further measuring device for measuring belt tension in a belt strand. This device uses a stamp which is moved against the belt strand until a predeterminable differential force is generated. After a further travel movement over a predetermined distance, a stamp force is measured on which the belt tension of the belt strand can be determined. With this mechanical measuring device for determining the belt tension, the belt and consequently the textile machine in which the belt is installed must also be brought to a standstill.This results in a production downtime of the textile machine, and the measurement must be performed manually using a handheld device and by a trained person. Above all, such mechanical measuring methods do not allow for gradual detection of changes in belt tension during operation of, for example, a textile machine. This also makes it impossible to initiate corrective measures in a timely manner to prevent consequential damage. For example, the control drive of a draw frame relies on optimal belt tension to maintain good control performance. Otherwise, the required quality of the textile machine's product, such as the fiber sliver, cannot be met.The object of the invention is to further develop a textile machine according to the preamble of claim 1, wherein the particularly permanent determination and monitoring of the belt tension between the drive unit and the rotating element is to be enabled with the least possible effort. This object is achieved on the basis of a textile machine according to the preamble of claim 1 in conjunction with the characterizing features. Advantageous developments of the invention are specified in the dependent claims. To achieve this object, the invention provides that an electrical force measuring device is set up with which forces acting on the shaft from the pulley over which the belt is guided can be measured.The core idea of the invention is a departure from classic mechanical-tactile measuring devices for measuring the belt tension of a belt between a drive unit and a rotating element, in that the belt tension force can be determined from the force to be measured between the pulley and a shaft using measurable electrical variables. It may therefore be sufficient to set up an electrical force measuring device (internal file number P229910WO1) in such a way that it only measures the forces that exist between the pulley, around which the belt is guided, and the shaft on which the pulley is rotatably mounted. The measurable forces are initially determined from a basic force of the belt, which exerts a certain force on the pulley and thus also on the shaft even when the textile machine is not in operation, and an operating force, which increases the basic force of the belt on the pulley.This allows for the continuous determination and monitoring of the belt tension between the drive unit and the rotating element with the least possible effort. Such a measuring arrangement is possible when a belt drive consists only of the actual belt and pulleys, which are created either on the drive unit, on an intermediate pulley or on a driven pulley, for example in direct connection with the rotating element. The shaft in this sense can be a stationary shaft on which the pulley rotates, or the pulley rotates with the shaft, which is accordingly mounted in the textile machine. Most pulleys are attached to shafts, which in turn are mounted in the machine with rotary bearings.In most cases, particularly in textile machines, the bearings are designed as rolling bearings, and both the forces to be transmitted by the belt and its tensioning forces are supported by the rolling bearings in the machine. By measuring the forces on the shaft according to the invention, the currently existing belt tensioning force can be determined. Such a measurement can be carried out during operation, thus overcoming the aforementioned disadvantages of the prior art. Advantageously, the force measuring device is arranged at least partially between the pulley and the shaft. The force measuring device is in particular arranged such that a force between the pulley and the shaft can be measured directly, for example via the lubrication gap of a bearing arrangement between the pulley and the shaft.In particular, a rolling bearing is provided, via which the pulley is rotatably mounted on the shaft, wherein the force measuring device is arranged in conjunction with 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, a lubricating gap created in the rolling bearing can serve as a measured variable, wherein the thickness of the lubricating gap is recorded using the electrical measuring unit, and the measured variable can be used to determine a force between the pulley and the shaft. Internal file number P229910WO1 With particular advantage, a belt tensioning device can be provided, wherein the pulley is arranged in conjunction with 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 tension.The belt tensioning device is particularly designed such that the shaft on which the pulley is mounted can be moved against the belt, for example via a carriage or equivalent means, so that the pulley of the belt tensioning device tensions the belt. The mounting of the pulley on the shaft in conjunction with the belt tensioning device and, in particular, a rolling bearing configured in this context is particularly suitable for implementing the electrical force measuring device according to the invention. The rolling bearing has, in particular, an inner ring and an outer ring, with rolling elements arranged between the inner ring and the outer ring, and the force measuring device is configured to apply an electrical voltage between the inner ring and the outer ring.If the outer ring rotates relative to the inner ring, a lubricant is introduced into the ring to create a lubricating film at the contact points or contact lines between the rolling elements and the inner ring or outer ring, which creates a geometric separation between the rolling elements and the rings. If the inner ring is mounted stationary on the shaft, the inner ring is insulated from the shaft and electrically contacted by the force measuring device. If the outer ring of the rolling bearing rotates, the electrical contact can be made with the outer ring using a sliding contact pickup or with a capacitive coupling. If an electrical potential is then applied between the contacts on the inner and outer rings of the rolling bearing, a change in the thickness of the lubricating film can be used to determine whether a force, particularly a radial force, is acting on the rolling bearing.Alternatively, the rolling bearing can also be integrated into an oscillating circuit, whereby the signaling to the components of the rolling bearing, and in particular the arrangement of the pulley on the shaft, is specified by the electrical measuring unit of the force measuring device. The rolling bearing can then act as a capacitor in the oscillating circuit if the inner ring and the outer ring are regarded as capacitor plates, between which the lubricant in the lubricating gap forms the dielectric. Furthermore, it is advantageous if a temperature measuring device is provided and configured to measure the temperature of the rolling bearing or at least components thereof. The temperature measuring device can, in particular, comprise a temperature sensor that is arranged in or on the rolling bearing and measures the temperature of the rolling bearing.The temperature measuring device is connected in particular to the force measuring device and preferably to the electrical measuring unit thereof. Internal file number P229910WO1 Furthermore, a speed measuring device is set up, with which the speed of the pulley on the shaft can be detected at least indirectly. In this case, it may be sufficient if the speed of a rotating element of the textile machine is known, which is coupled via the belt to the pulley arranged on the shaft, wherein the force measuring device is set up between the pulley and the shaft. If the speed of the drive unit or the speed of the rotating element is known, the speed of the outer ring relative to the inner ring of the rolling bearing can be deduced from the speed of the pulley on the shaft.The speed measured by the speed measuring device is also recorded by the force measuring device and in particular by the electrical measuring unit of the force measuring device. If the electrical force measuring device is installed on the textile machine, referencing can initially be carried out using another, for example, mechanically or electrically acting force measuring device, such as on the belt tensioning device with which the belt tension is determined. The electrical force measuring device can then be referenced according to the invention, in particular across the operating range of the textile machine and the belt, over which the belt tension is to be measured and in particular monitored. The textile machine is designed in particular as a draw frame for spinning preparation. The belt can be a component of the drafting system and, for example, drive upper rollers and / or lower rollers.The force measuring device comprises, in particular, an electrical measuring unit. The textile machine further comprises a control device to which the electrical measuring unit is connected, such that the force value of the belt is output from the force measuring device to the control device, monitored by the control device, and can be displayed, for example, to an operator. Furthermore, a measuring device for measuring the properties of a fiber sliver that is processed or worked by the textile machine can be provided, in particular a measurement of the mass of the fiber sliver per length. The control device of the textile machine is configured to relate or correlate measured values from the electrical measuring unit and measured values from the measuring device for measuring the properties of a fiber sliver.Textile machines, especially those used in spinning preparation, typically process and deliver a fiber strand as a fiber product, the quality of which can be monitored. Thus, it is possible, in a conventional manner, to regularly or continuously monitor the drawing of a fiber strand emerging from the drafting system of a draw frame, which is also done at least indirectly via the textile machine's control system.If, according to the invention, the control device (internal file number P229910WO1) now has a value for the belt tension of a belt from the drafting system available, the value from the monitoring of the fiber strand, i.e. the value of the drafting, measured on the length-specific weight of the fiber strand, can be correlated with the value for the belt tension by means of the control device, which, for example, enables a much simpler and proactive control of the textile machine during operation, since it is easier to make statements about the cause, for example, of a deviating measured value regarding the quality of the fiber product.
[0002] Internal file number P229910WO1 Further measures improving the invention are described in more detail below, together with the description of a preferred embodiment of the invention, with reference to the figures. They show: Fig. 1: an example of a textile machine using a draw frame with a drafting system, Fig. 2: an isolated drive train of the drafting system with the components of the gear box, Fig. 3: the belt tensioning device in an isolated view, and Fig. 4: the force measuring device arranged on a roller bearing which is part of the gear box of the drafting system or the belt tensioning device of the draw frame. Figure 1 shows an example of a textile machine 1 using a draw frame 2 with a drafting system 3, and the drafting system 3 has a plurality of rotating elements 11, one of which element is shown as a bottom roller which is driven by a drive unit 10 via a belt 12.The belt 12 is guided over several pulleys 25, 26, 27, with a drive pulley 28 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. Furthermore, a belt tensioning device 17 is provided, which has a pulley 13 over which the belt 12 is guided, and the pulley 13 is rotatably mounted on a shaft 14. The belt tensioning device 17 enables displacement of the shaft 14 and thus of the pulley 13, so that the belt 12 can be tensioned via the belt tensioning device 17. Figure 2 shows the drive train of the drafting system with the individual components of the transmission, thus the belt 12, the rotating element 11 (alternatively by the associated pulley), the other pulleys 25, 26 and 27 as well as the 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 means 29 with which the shaft 14 and thus also the pulley 13 can be displaced in the direction of force F shown in order to apply belt tension to the belt 12. Figure 3 shows the belt tensioning device 17 in an enlarged view, wherein the tensioning means 29 is shown as a pressure rod and interacts with a carriage 30 which can be guided in the direction of the arrow in a machine-fixed guide (not shown) so that the tensioning force F can be applied. Internal file number P229910WO1 The shaft 14 is fixedly attached to the carriage 30 and the pulley 13 is rotatably mounted on the shaft 14, around which the belt 12 can be looped. The pulley 13 is rotatably mounted on the shaft 14 by means of a rolling bearing 16, wherein a force measuring device 15 is arranged in connection with the rolling bearing 16.The force measuring device 15 has a first electrical contact 31, which is in contact with an inner ring 18 of the rolling bearing 16, wherein the inner ring 18 is received on the shaft 14, in particular in an electrically insulated manner. A further 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 thus electrically connected to the rotating outer ring 19 of the rolling bearing 16. The electrical measuring unit 23 is preferably also operatively connected to the control device 24 of the textile machine, so that measured forces of the force measuring device 15 can be detected by the control device 24 of the textile machine and, in particular, displayed or monitored. Figure 4 shows the pulley 13 on the shaft 14, and the belt 12, which wraps around the pulley 13, is partially shown.The rolling bearing 16 is designed with the inner ring 18 and the outer ring 19 to rotatably support the pulley 13 on the shaft 14, and a plurality of rolling elements 20 are located between the rings 18 and 19. Lubrication gaps 33 are located 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 if the outer ring 19 rotates relative to the inner ring 18, a geometric separation of the solid contact of the rolling elements 20 to the running surfaces in the inner ring 18 and the outer ring 19 occurs.The geometric separation occurs via the lubrication gaps 33 based on the hydrodynamic effect, and if an electrical potential is applied between the inner ring 18 and the outer ring 19 via the electrical contacts 31, 32, an acting force between the inner ring 18 and the outer ring 19 can be determined from the thickness of the lubrication gaps 33 after appropriate referencing. Such a force determination can be carried out, for example, in the electrical measuring unit 23. A value for the clamping force F can then be output using the electrical measuring unit 23. The invention is not limited in its embodiment to the preferred embodiment specified above. Rather, a number of variants are conceivable which make use of the solution presented even in fundamentally different designs.All features and / or advantages arising from the claims, the description or the drawings, including design details or spatial arrangements, can be essential to the invention both individually and in a wide variety of combinations.
[0003] Internal file number P229910WO1 Reference number 1 Textile machine 2 Draw frame 3 Drafting system 10 Drive unit 11 Rotating element 12 Belt 13 Pulley 14 Shaft 15 Force measuring device 16 Rolling bearing 17 Belt tensioning device 18 Inner ring 19 Outer ring 20 Rolling element 21 Temperature measuring device 22 Speed measuring device 23 Electrical measuring unit 24 Control device 25 Pulley 26 Pulley 27 Pulley 28 Drive pulley 29 Clamping device 30 Carriage 31 Electrical contact 32 Electrical contact 33 Lubrication gap F Tension force
Claims
Internal file number P229910WO1 Patent claims 1. Textile machine (1), comprising a drive unit (10) and at least one rotating element (11), wherein a belt (12) is tensioned between the drive unit (10) and the rotating element (11), and wherein the belt (12) is guided over at least one pulley (13) which is received on a shaft (14), characterized in that an electrical force measuring device (15) is set up, with which forces acting from the pulley (13) on the shaft (14) can be measured.
2. Textile machine (1) according to claim 1, characterized in that the force measuring device (15) is arranged at least partially between the belt pulley (13) and the shaft (14). 3.Textile machine (1) according to claim 1 or 2, characterized in that a rolling bearing (16) is provided, so that the pulley (13) is rotatably mounted on the shaft (14) by means of the rolling bearing (16), wherein the force-measuring device (15) is arranged in connection with the rolling bearing (16).
4. Textile machine (1) according to one of claims 1 to 3, characterized in that a belt tensioning device (17) is provided, wherein the pulley (13) is arranged in connection with the belt tensioning device (17) and is adjustable relative to the belt (12) by means of the belt tensioning device (17) in order to change the belt tension. 5.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 elements (20) are arranged between the inner ring (18) and the outer ring (19), and wherein the force measuring device (15) is designed to apply an electrical voltage between the inner ring (18) and the outer ring (19).
6. Textile machine (1) according to one of the preceding claims, characterized in that a temperature measuring device (21) is provided and is designed to metrologically detect the temperature of the rolling bearing (16) or at least components thereof.
7. Textile machine (1) according to one of the preceding claims, characterized in that a speed measuring device (22) is designed to at least indirectly detect the speed of the pulley (13) on the shaft (14). Internal file number P229910WO1 8. 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. Textile machine (1) according to claim 8, characterized in that the belt (12) drivingly connects a drive unit (10) of the draw frame (2) to a bottom roller.
10. 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), the electrical measuring unit (23) being operatively connected to the control device (24), and the control device (24) monitoring the belt tension via the connection to the measuring unit (23).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 sliver which is processed or treated by means of the textile machine (1), in particular a measurement of the mass of the fiber sliver per length, wherein the control device (24) of the textile machine (1) is designed to relate or correlate measured values of the electrical measuring unit (23) and measured values of the measuring device for measuring the properties of a fiber sliver to one another.