Device with guide unit for guiding a conveyor belt

Description

[0001] The invention relates to a device for guiding a conveyor belt, in particular a conveyor belt for transporting bulk material, comprising a guide unit with an outer and an inner, hollow cylindrical body, wherein the inner hollow cylindrical body has a first central axis and is arranged in the outer hollow cylindrical body, which has a second central axis, with at least one bearing for the rotatable mounting of the outer hollow cylindrical body on the inner hollow cylindrical body and with a joint body designed to mount the inner hollow cylindrical body on a central axis, wherein the joint body is further designed to enable a horizontal and / or vertical angular change of the first and / or second central axis relative to a central axis of the central axis. The central axis can be mounted in holders in a rotationally rigid or rotatable manner.The joint body can be designed, for example, as a rubber body or rubber bearing. Furthermore, the invention relates to a system for monitoring and guiding a conveyor belt with a device of the aforementioned type.

[0002] The inner hollow cylindrical body and the outer hollow cylindrical body can also be called inner tube and outer tube.

[0003] Conveyor belts are used in belt conveyors to transport bulk materials such as coal, ore, sand, cement, and the like, enabling a continuous flow of material. They enable long conveying distances, high conveying volumes, and high conveying speeds with comparatively low drive power.

[0004] A variety of causes can lead to misalignment and / or off-centered running of the conveyor belt during operation of a belt conveyor system. This increases wear on the conveyor belt, which can lead to higher maintenance costs and downtime, and reduces the efficiency and cost-effectiveness of the belt conveyor system. In particularly severe cases, it can even lead to a failure of the belt conveyor system due to an unexpected mechanical failure of the conveyor belt. Examples of causes that can affect belt tracking include faulty or inadequate belt connections, dirty idlers, idlers that are not perpendicular to the belt travel direction, defective idlers, defects in the belt tension member, axial misalignment in parts or an entire belt system, and environmental influences, particularly wind, ice, and snow.

[0005] To prevent or reduce belt tracking errors, conveyor belt systems sometimes use devices of the type mentioned above to guide the conveyor belt (cf. WO 03 / 068638 A1, which discloses the preamble of claim 1). In the assembled state, in which the central axis is mounted by means of two bearings attached to a support frame of the conveyor belt system, the guide unit, in particular the outer hollow cylindrical body, is in contact with the conveyor belt in such a way that the belt tracking can be influenced by a control intervention of the device.Such a control intervention is understood to mean a rotation and / or inclination of the guide unit, wherein the rotation of the guide unit is characterized by a substantially horizontal angular change of the first and / or second central axis relative to a central axis of the central axis, and the inclination of the guide unit is characterized by a substantially vertical angular change of the first and / or second central axis relative to a central axis of the central axis. A disadvantage of such prior art devices is that control interventions attributable to causes requiring prompt maintenance or shutdown of the system are not detected in a timely manner.

[0006] Based on this, the object of the invention is to provide a device for guiding a conveyor belt with which the service life of a conveyor belt can be increased.

[0007] This object is achieved by a device having the features specified in claim 1. Preferred and advantageous embodiments of the device according to the invention are specified in the subclaims.

[0008] To achieve the object, a device of the type mentioned at the outset is proposed which, according to the invention, is equipped with a measuring and evaluation system having at least one sensor unit, wherein the sensor unit is arranged inside and / or outside the guide unit and the measuring and evaluation system is designed to detect the change in angle.

[0009] The invention is based on the consideration that the causes of a belt running error can be identified, derived or limited from a control behavior of the device.

[0010] The control behavior of the device is understood to mean all or a multitude of control interventions occurring during operation of the conveyor belt system, whereby the control behavior can be represented as a control curve. This control behavior changes with the operating state of the conveyor belt system. For example, a basic control behavior can be distinguished from a control behavior during normal operation, whereby a basic control behavior is characterized by all or a multitude of control interventions during a zero measurement (of an unloaded new belt conveyor system or a properly maintained belt conveyor system), while a control behavior during normal operation is characterized by all or a multitude of control interventions with a loaded conveyor belt.Deviating control interventions, which are usually characteristic of the cause causing the control intervention, therefore indicate an operating condition that deviates from normal operation. Since the control intervention causes an angle change, a detected angle change can be used to identify the cause(s) of the control intervention or at least to narrow it down to a limited number of possible causes.

[0011] Knowing the cause(s) for one or more control interventions enables an assessment of any countermeasures that may be necessary, for example to reduce wear on the conveyor belt and thus increase the service life (service life) of the conveyor belt or to avoid unforeseen failures of the entire conveyor belt system as a result of a mechanical failure of the conveyor belt or another part of the conveyor belt system.

[0012] For this purpose, at least one sensor unit or a measuring and evaluation system comprising at least one sensor unit is arranged inside and / or outside the guide unit, preferably on the central axis, for example on the outer surface of the central axis, or held on or in the joint body, wherein the sensor unit is designed to measure an angular change (direct detection) or a measured variable related to the angular change (indirect detection). A measured variable related to the angular change can also be referred to as a measured variable proportional to the angular change. The sensor unit can be arranged in a housing of the measuring and evaluation system or remotely from it, inside and / or outside the guide unit. The sensor unit is preferably arranged in a protected manner within the guide unit, preferably within the outer hollow cylindrical body of the guide unit.An evaluation unit of the measuring and evaluation system can be arranged inside or outside the guide unit, for example on the central axis outside the hollow cylindrical body. Preferably, the evaluation unit of the measuring and evaluation system, together with the at least one sensor unit, is also arranged inside the guide unit, for example on the central axis. Alternatively, the at least one sensor unit and / or the evaluation unit of the measuring and evaluation system can also be arranged outside the guide unit, specifically both outside the inner hollow cylindrical body and outside the outer hollow cylindrical body of the guide unit. The evaluation unit or the measuring and evaluation system can each be connected to a system control system, for example a control room, and / or to an alarm device positioned near the guide unit.Alternatively or additionally, wireless communication between the evaluation unit or the measurement and evaluation system and maintenance personnel is also within the scope of the present invention. Maintenance personnel can then initiate measures to rectify a malfunction if necessary.

[0013] According to a further embodiment of the invention, the communication of the evaluation unit or the measuring and evaluation system with a system control system, for example a control room, and / or with maintenance personnel can advantageously be carried out by means of WLAN and / or via Internet remote monitoring.

[0014] If the sensor unit measures a variable related to the angle change, the measurement and evaluation system can detect the angle change based on this variable. Preferably, the sensor unit is arranged in such a way that the detection of an angle change in the vertical or horizontal direction is possible.

[0015] An example of a measured variable related to the change in angle is the distance between individual components of the device which are moved relative to one another during a control intervention. For example, during a control intervention of the device, due to the special design of the joint body, the distance between the outer surface of the central axis and a (first) inner surface of the cylinder jacket of the inner hollow cylindrical body and / or a (second) inner surface of the cylinder jacket of the outer hollow cylindrical body changes in the horizontal and / or vertical direction. From the distances measured by the sensor unit before and during the control intervention or during and after the control intervention, the change in angle is recorded and determined by the measuring and evaluation system, with the recording and / orDetermination, which in indirect measurement corresponds to calculating the angular change from the difference in distances, requires that the distance between a specified first axial position of the sensor unit relative to the center axis of the central axis and a second axial position spaced from this position, again relative to the center axis of the central axis, be known. This second axial position can, for example, be defined by the joint center point of the joint body, with the first axial position of the sensor unit being axially spaced from the second position on the center axis of the central axis.

[0016] In an advantageous embodiment of the invention, the measuring and evaluation system can have at least one second sensor unit, preferably a second, a third and a fourth sensor unit, which is or are arranged within the guide unit, in particular within the housing of the measuring and evaluation system, and is or are designed for direct or indirect detection of the angular change. The use of at least two sensor units enables the detection of angular changes in two different directions, for example in the horizontal and in the vertical direction, so that causes for control interventions can be identified which cause an angular change in a direction different from the running direction of the conveyor belt, which coincides, for example, with the horizontal direction. The detection of angular changes which have a horizontal and a vertical component is also possible.The at least one second sensor unit is arranged such that an angle exists between a measuring direction of the first sensor unit and a measuring direction of the second sensor unit, which angle corresponds to the angle between the directions in which an angular change is to be detected. The sensor elements can be arranged in a common plane extending perpendicular to the central axis of the central axis. An arrangement of the sensor elements spaced apart along the central axis of the central axis is also conceivable.

[0017] The measurement direction is understood to be the direction in which the sensor unit enables the measurement of the angle change or the measurement of a measurand related to the angle change. For example, the measurement direction of a sensor unit based on an optical distance measurement method is the direction in which the emission and detection of light required for measuring the distance is possible.

[0018] For example, if the angle change is to be recorded in both vertical and horizontal directions, the angle between the measuring directions of the first and second sensor units is preferably approximately 90°. However, the angle between the measuring directions can be adjusted to suit the measurement requirements.

[0019] Furthermore, the arrangement of additional sensor units within the guide unit is advantageous in order to improve the accuracy of the detected angular change through the increased number of sensor elements, to enable detection in any number of directions, or to increase the reliability of the measurement and evaluation system through a redundant arrangement of the sensor elements. This allows a failure or severe contamination of individual sensor elements to be compensated for until the system is scheduled for maintenance. To further improve accuracy or reliability, the sensor units can each be based on different measuring principles.

[0020] According to a further advantageous embodiment of the invention, the at least one sensor unit is based on a non-contact measuring principle for measuring the angular change or a measured variable associated with the angular change. The at least one sensor unit can be, for example, an acoustic, inductive, capacitive, magnetic, optical, or piezoelectric sensor unit. For example, an inductive sensor unit can be arranged on the lateral surface of the central axis, provided that the first and / or the second hollow cylindrical body consists at least partially of an electrically conductive material. An advantageous embodiment of the invention is characterized in that the at least one sensor unit comprises optical laser sensors. Such sensors (laser sensors) are comparatively inexpensive to obtain.

[0021] The use of a sensor unit based on a non-contact measuring principle has the advantage that the rotation of the guide system relative to the central axis of the device does not lead to wear of the sensor, so that a long service life of the sensor unit is achieved and no failure due to wear of the sensor unit is to be expected.

[0022] In addition, the measuring and evaluation system can comprise at least one storage and processing unit. The storage and processing unit is configured to store detected angle changes and / or to compare a detected angle change with stored angle changes. The storage and processing unit preferably comprises all components required for storing and processing data, for example, a microprocessor and a data storage unit, with the data storage unit being permanently or detachably connected to the storage and processing unit. Further preferably, the storage and processing unit is an integral part of the measuring and evaluation system, which then comprises the required components and is designed, for example, as a single-board computer or the like.

[0023] The storage and processing unit makes it possible to store the angular changes that characterize control interventions performed by the device during operation over the entire operating period of the device according to the invention, or at least over a portion of it. Thus, based on the obtained data, the operating behavior of the conveyor belt can be evaluated, and the causes of the control interventions, which, for example, lead to increased wear on the conveyor belt, can be identified or narrowed down.

[0024] A comparison by the storage and processing unit of an angular change recorded by the measuring and evaluation system with one or more stored angular changes makes it possible to identify deviating angular changes and thus deviating control interventions that indicate an operating state of the conveyor belt that deviates from normal operation. In this case, comparison is understood to mean a comparison, in particular a calculation of the difference, of two or more angular changes, whereby the comparison includes the time, frequency, direction and amplitude of the angular change. The angular changes stored in the storage and processing unit can correspond to angular changes that were recorded by the measuring and evaluation system during previous operation of the conveyor belt and / or correspond to angular changes that were recorded before operation of the conveyor belt, in particular during a zero measurement and / or normal operation.It is also within the scope of the invention that the angle changes stored in the storage and computing unit are based on empirical values ​​available for the conveyor belt or, for example, were calculated using a computer model when designing the system comprising the conveyor belt.

[0025] Detected deviations can be marked separately using data technology and stored, for example, as an error log in the storage and processing unit, separately from the angle changes that have been stored or are to be stored. The detected deviations can also be assigned a data field that uniquely identifies the deviation and contains attributes such as frequency, date, time, possible cause of the deviation and / or group of causes of the deviation, or similar information. A deviation exists if the numerical value obtained by the comparison exceeds a previously defined permissible value stored in the storage and processing unit.

[0026] Additionally, the measurement and evaluation system can provide an indication signal when the computing and storage unit detects a deviation. The indication signal can be identical or specific for each deviation. For example, it is possible for the indication signal for a deviation caused by control intervention due to contaminated support rollers, in particular contaminated return-strand support rollers, to be different from the indication signal indicating a deviation caused by control intervention due to a belt connection fault. The indication signal can thus be used as an indicator of the causal cause of the control intervention and / or to notify maintenance personnel.

[0027] In a further embodiment, a voltage source, preferably a rechargeable voltage source, can be arranged within the guide unit and / or, for example, within the measuring and evaluation system. The voltage source is designed to supply the at least one measuring and evaluation system and can be arranged detachably or permanently inside or outside the guide unit. By using a voltage source arranged in the guide unit, the measuring and evaluation system can be supplied with the voltage required for operation without the need for a complex and potentially failure-prone connection of the measuring and evaluation system to an external voltage source. An external voltage source is understood to be a voltage source that is arranged outside the guide unit.By arranging the voltage source within the guide unit, the voltage source is also advantageously shielded against environmental influences, in particular against rain or against bulk material transported by the conveyor belt.

[0028] Alternatively or in addition to a power supply via a voltage source, preferably a rechargeable voltage source, arranged near or within the control unit and / or the measuring and evaluation system, it is also within the scope of the invention to supply the measuring and evaluation system and / or the at least one sensor unit with electrical energy via supply cables from an external power source. In this regard, one can also speak of a wired power supply of the measuring and evaluation system and / or the at least one sensor unit. It is also within the scope of the invention to connect the measuring and evaluation system to an external system control or monitoring device, for example a control room, via data cables or signal lines.

[0029] Preferably, supply electronics can be arranged within the guide unit and configured for wired or contactless supply of the measuring and evaluation system and / or for wired or contactless supply of the voltage source. The electrical energy required to supply the measuring and evaluation system is preferably transmitted using near-field transmission technology, with the electrical coupling between the supply electronics (transmitter) and the measuring and evaluation system (receiver) preferably being implemented as an inductive, resonant inductive, magnetic resonant, or capacitive coupling.

[0030] In a further embodiment of the device, the measuring and evaluation system has an interface unit, which is configured, for example, for a wireless signal connection. The interface unit enables wireless communication between the measuring and evaluation system and an external receiver. Data acquired by the measuring and evaluation system or stored in the storage unit can be forwarded to a receiver via wireless communication. In addition, the interface can be used to store angle changes in the storage and processing unit for use in calibration. Wireless communication can be implemented using a suitable radio technology, which can be selected depending on the application of the system comprising the device.The wireless signaling connection eliminates the need for long cable connections to the device, for example, when it is used in a very decentralized location on a belt conveyor in a large open-cast mine. A wireless signaling connection can be established both to centrally located receivers, such as a host system or client server, and to decentralized and / or mobile receivers, such as a handheld device or smartphone.

[0031] A further embodiment of the invention provides for signal amplification elements, for example, signal-amplifying wall sections, to be arranged within the guide unit. The signal amplification elements can be formed, for example, by a coating or an additional element applied to the wall section or attached to the wall section. It is also within the scope of the invention for the body comprising the wall section to be designed, at least in sections, as a signal amplification element.

[0032] A signal amplification element is an element that improves the measurement signal of a sensor element used to detect the change in angle. For example, a section of the inner surface of the inner hollow cylindrical body is electrically conductive or partially provided with a coating with a high degree of reflection in order to improve the measurement signal of an inductive or optical sensor element. The section can have an elongated extension in the axial direction and / or in the circumferential direction. The signal amplification element(s) are preferably arranged such that they lie opposite the sensor element in the measuring direction. In addition to signal improvement, the arrangement of at least one signal amplification element can also be used to expand the range of available measurement methods.For example, if the inner hollow cylindrical body is made of an electrically non-conductive material, the use of an inductive sensor unit is enabled by arranging a signal amplification element made of an electrically conductive material.

[0033] According to a further advantageous embodiment of the invention, sealing elements are arranged within the guide unit, for example in the region of a first end and in the region of a second end of the outer hollow cylindrical body or the inner hollow cylindrical body. The sealing elements can be designed as spring bellows, rubber sleeves, or as lamellar or brush seals, whereby the selection of the sealing elements can be made taking into account the rotational speed of the outer and / or inner hollow cylindrical body. The sealing elements can be mounted on the central axis or arranged on the first or second inner surface of the cylinder jacket or on the inner hollow cylindrical body. A combination of these options is conceivable if the sealing elements have multiple components.For example, at comparatively high speeds, brush seals can be used as sealing elements. These are arranged on the first cylinder inner surface such that bristles forming a brush seal are aligned radially inward toward the central axis. Upon a change in angle, the bristles made of elastic material are partially compressed or deflected from their original position, and the reduction in the distance between the first cylinder inner surface and the surface of the central axis resulting from the change in angle is compensated. Alternatively or in addition to the brush seals, spring bellows or rubber sleeves can be sealingly connected to the inner hollow cylindrical body, preferably to its outer surface, and the central axis.The spring bellows or rubber sleeves are preferably designed to seal the rolling bearings arranged between the outer hollow cylindrical body and the inner hollow cylindrical body against the ingress of dirt. The sealing elements, preferably spring bellows, prevent or reduce the ingress of foreign material, for example, dust-like foreign material, into the guide unit, so that components arranged within the guide unit, for example, the at least one sensor unit or the measuring and evaluation system and the joint body and / or rolling bearing, are hardly contaminated. This advantageously increases the service life of the components and avoids or reduces disruptive influences on the detection of the angular change, especially when the sensor elements used are based on a non-contact measuring principle.

[0034] According to a further advantageous embodiment of the invention, the at least one sensor unit or the measuring and evaluation system is mounted on the central axis or on the inner hollow cylindrical body, preferably pushed onto the central axis or plugged onto the inner hollow cylindrical body. For this purpose, the components of the sensor unit or of the measuring and evaluation system can be arranged in a housing which, for example, is essentially annular and has a central recess whose dimensions are adapted to the diameter or profile dimensions of the central axis. The radial extent of the housing is significantly smaller than the inner diameter of the outer or inner hollow cylindrical body, such that the housing can be introduced into the guide unit and, in the assembled state, can rotate orInclination of the hollow cylindrical body relative to the central axis is permitted, so that the guiding function (steering function) of the guiding unit is possible without restriction. Preferably, the housing is detachably mounted on the central axis. Thus, the measuring and evaluation system can be pulled out of the guiding unit, for example for maintenance purposes or to replace the voltage source, and then pushed back into its original position within the guiding unit. Such a configuration also enables the retrofitting of existing devices that previously did not have a measuring and evaluation system. Further preferably, the central axis can have an axial stop and / or a guiding element, for example a groove or tongue, for improved reproducibility of a bearing position, which includes both an axial position of the system along the central axis and an angular position relative to the vertical and / or horizontal direction.Furthermore, for improved reproducibility of the angular position, a position sensor or stabilizer, for example a gyroscope, can be integrated within the measuring and evaluation system.

[0035] According to a further advantageous embodiment, the device according to the invention is designed as a self-learning system. Thus, after a sufficient measurement period and data availability, the device according to the invention allows, if necessary, a conclusion to be drawn about a specific malfunction of a conveyor belt system. This advantageously allows the causes of malfunctions in the conveyor belt system in question to be identified.

[0036] An advantageous embodiment of the invention is characterized in that the measuring and evaluation system is arranged outside the inner hollow cylindrical body. The at least one sensor unit and the evaluation unit of the measuring and evaluation system are preferably arranged at a distance from one another. In this case, for example, a sensor holder is plugged onto one end of the inner hollow cylindrical body and connected to it preferably by force or friction. The sensor holder is preferably bush-shaped. A sealing element, preferably in the form of a spring or rubber bellows, can be connected to the sensor holder. The sealing element is connected to the central axis and seals the interior of the hollow cylindrical body against the ingress of dust. The at least one sensor unit of the measuring and evaluation system is installed on the sensor holder.For example, the sensor holder is provided with four sensor units (sensors) that are distributed around the circumference of the bush-shaped sensor holder and arranged at a distance from one another. The sensor units preferably measure contactlessly in the direction of the central axis. An evaluation unit of the measuring and evaluation system can, for example, be mounted outside the outer hollow cylindrical body of the guide unit on a bracket supporting the central axis. Furthermore, at least part of a supply electronics system can also be arranged on the sensor holder. For example, mutually associated elements of a generator system of the supply electronics can be arranged on the outer surface of the sensor holder or on the inside of the outer hollow cylinder.

[0037] A further embodiment of the invention is characterized in that the at least one sensor unit is arranged at the end of the outer hollow cylindrical body, preferably substantially or largely outside the outer hollow cylindrical body, wherein a sensor holder is plugged onto the central axis and is preferably connected to it in a force-locking or frictional manner. The sensor holder is, for example, bush-shaped and preferably has several, e.g., four sensor units (sensors) that are distributed over the circumference of the sensor holder and arranged at a distance from one another. The sensor units preferably measure contactlessly in the direction of a reflector body or bush-shaped body that surrounds the sensor holder at a radial distance and is preferably connected to the end of the outer hollow cylindrical body in a rotationally fixed manner.For this purpose, the reflector body or bushing-shaped body has a connecting section that is inserted into the outer hollow cylindrical body by force or friction. The sensors (sensor units) are connected to an evaluation unit of the measuring and evaluation system via signal lines, for example in the form of one or more cables. The evaluation unit can, for example, be mounted outside the outer hollow cylindrical body of the guide unit on a bracket supporting the central axis.

[0038] The object indicated above is also achieved by a system for monitoring and guiding a conveyor belt with a device according to the invention according to one of the above-mentioned embodiments and a receiving unit, wherein the receiving unit is prepared for a signaling connection with the measuring and evaluation system.

[0039] The recording unit can be connected to the measuring and evaluation system, for example, via a signal line or radio technology. The signal connection makes it possible to transmit the angular changes detected by the measuring and evaluation system to the recording unit, whereby the transmitted angular changes can also correspond to angular changes detected during the duration of the connection or stored in the storage and processing unit of the measuring and evaluation system. A combination of these possibilities is also within the scope of the invention. Preferably, all other data and / or signals stored and / or generated by the measuring and evaluation system can also be transmitted, in particular an error log resulting from the comparison. The connection can also be used to transfer the angular changes required for the comparison to the storage and processing unit.The recording unit preferably has an interface, in particular a bus system, for the data connection to an external data storage device on which the angle changes to be transmitted to the measurement and evaluation system are stored or on which the angle changes recorded and / or stored by the measurement and evaluation system can be stored. The external data storage device can preferably be connected to any computing unit, and the stored data can be evaluated. For example, the data can be used for the development of algorithms that predict the control behavior of a system.

[0040] The recording unit preferably comprises an optical signaling device and / or is configured for connection to an optical signaling device. The optical signaling device can comprise at least one illuminant, preferably an LED or an LED array. The optical signaling device can use the illuminant to constantly or periodically emit a light signal perceptible to a person when the optical signaling device receives an activation signal. The activation signal can preferably be provided by the measuring and evaluation system or by the recording unit, wherein the activation signal corresponds to the indication signal of the measuring and evaluation system or is an independently generated signal. Depending on the activation signal, the illuminant of the optical signaling device emits one or more light signals to inform an observer about the operating status of the device or the system.For example, light is emitted periodically if a deviation or an angle change has been detected as a result of a control intervention, which indicates an operating state deviating from normal operation. An observer can thus be informed of an operating state that requires intervention or maintenance. The optical signal unit can preferably comprise further light sources so that a normal operating state, an operating state deviating from this, and a critical operating state, for example an operating state causal for a possible failure of the system, can be indicated by means of different light sources. The emitted light can originate from different spectral ranges of visible light, for example from a green, a yellow, and a red spectral range, whereby different light colors can be used as an indicator of the operating state.The signaling device preferably comprises at least one green, one yellow and one red illuminant, whereby illuminants are understood to mean illuminants which each emit light in the spectral range associated with the colour.

[0041] In a further embodiment of the system according to the invention, the receiving unit comprises an acoustic signaling device and / or is configured for connection to an acoustic signaling device. The acoustic signaling device preferably comprises a sound transducer and the necessary control and transducer elements for generating an acoustic signal and can be arranged in the housing or remotely from the housing of the receiving unit. The acoustic signaling device emits a tone and / or tones constantly or periodically, depending on the activation signal, which, for example, alerts maintenance personnel to an operating state that deviates from normal operation.

[0042] The recording unit of the system can preferably have an evaluation unit and / or a display unit. The storage and processing unit of the evaluation unit is preferably configured, analogous to the storage and processing unit of the measuring and evaluation system, for storing detected angle changes and / or for comparing a detected angle change with stored angle changes and preferably also comprises the components required for storing and processing data. The display unit, for example an LCD or OLED display, is arranged in a housing of the recording unit in such a way that it can be read by a user. It is configured to display the operating status of the conveyor belt; for this purpose, a color code indicating the operating status, plain text, a numerical code, or the like can be displayed.

[0043] The presence of a storage and processing unit in the recording unit makes it possible to provide the storage and processing unit redundantly, so that in the event of a failure of the storage and processing unit of the measuring and evaluation system or the recording unit, the detected angle changes can still be stored and compared and / or an activation signal can be generated that indicates the failure of the measuring and evaluation system or an interrupted connection between the measuring and evaluation system and the recording unit via the optical and / or acoustic signaling device. However, it is also within the scope of the invention for only a single storage and processing unit to be present in the recording unit.

[0044] In a further embodiment of the system according to the invention, the recording unit is designed as a handheld device. In this embodiment, the components required for comparing the recorded and / or stored angle changes are integrated in the handheld device. The handheld device can preferably be connected to the measuring and evaluation system via a wireless signal connection so that the required data can be transmitted via this connection. In addition, the handheld device preferably comprises a display unit, e.g. a screen, which is designed to show the operating status of the conveyor belt and / or the conveyor belt system. By evaluating and displaying the data on the handheld device, a technician carrying out maintenance receives information about the cause or causes that led to a deviation.Accordingly, the technician is able to carry out the necessary work in a targeted and time-saving manner, so that the system downtime can be kept as short as possible.

[0045] The data transmission in the device according to the invention or in the system according to the invention can be wireless or wired.

[0046] A further advantageous embodiment of the system according to the invention is characterized in that the conveyor belt has or is provided with a marker, wherein the system comprises a sensor for determining a measurement period and / or rotation time of the marker. This allows additional measurement data relating to the measurement period or rotation time to be recorded, which can be combined, for example, with measurement data provided by the above-mentioned measurement and evaluation system.

[0047] According to a further advantageous embodiment of the system according to the invention, this comprises one or more sensors for detecting the rotational speed of one of the belt drums or support rollers, preferably of the outer hollow cylindrical body of the guide unit, and / or for detecting the conveyor belt position on one of the belt drums or support rollers, for example on the outer hollow cylindrical body of the guide unit.

[0048] The invention is explained in more detail below with reference to a drawing illustrating exemplary embodiments. The drawings show schematically: Fig. 1 shows a device according to the invention for guiding a conveyor belt, in a longitudinal section; Fig. 2 shows the device of Fig. 1in the same longitudinal section, wherein a guide unit of the device for a control intervention on the conveyor belt is rotated from a normal position into a steering position; Fig. 3 a measuring and evaluation system in a perspective view; Fig. 4 a system for monitoring and guiding a conveyor belt with a device for guiding a conveyor belt and a receiving unit in an overview; Fig. 5 a further embodiment of a device according to the invention for guiding a conveyor belt, in a longitudinal section; Fig. 6 the device of Fig. 5in the same longitudinal section, wherein a guide unit of the device for controlling the conveyor belt is rotated from a normal position into a steering position; Figs. 7 and 8 show further embodiments of a device according to the invention for guiding a conveyor belt, each in a longitudinal section, wherein a guide unit of the device for controlling the conveyor belt is rotated from a normal position into a steering position; Fig. 9a show a further embodiment of a device according to the invention for guiding a conveyor belt, in a longitudinal section; Figs. 9b and 9c show a cross-sectional view of the device from Fig. 9a along the section line IXb-IXb in Fig. 9c or an enlarged view of detail IXc in Fig. 9a ; Fig. 10a shows a further embodiment of a device according to the invention for guiding a conveyor belt, in a longitudinal section; and Fig. 10b shows the left end of the guide unit of the device from Fig. 10a, in a perspective view.

[0049] In Fig. 1 A device 1 for guiding a conveyor belt (not shown) is shown. The device 1 generates steering movements to counteract any misalignment of the conveyor belt.

[0050] As is well known, a conveyor belt rests on rollers (support rollers) on both the upper and lower runs. These rollers are mounted, for example, in roller blocks mounted in the support frame. Typically, there are different roller blocks for the upper and lower runs of the conveyor belt, which are attached to the support frame's support beams. The roller blocks on the upper run (upper run) usually carry three rollers arranged in a trough. The rollers on the lower run (lower run) are often designed as individual rollers.

[0051] The device 1 for guiding or steering a conveyor belt according to Fig. 1is preferably arranged in the underrun of the belt. The device 1 has a guide unit 2 with a central axis 7. The central axis 7 is mounted, for example, on the support frame of a belt conveyor by means of lateral brackets 10. The central axis 7 is preferably fixedly mounted and does not transmit any rotary movements.

[0052] The guide unit 2 has an outer hollow cylindrical body 3 and an inner hollow cylindrical body 4. The inner hollow cylindrical body 4 is arranged in the outer hollow cylindrical body 3, wherein the outer hollow cylindrical body 3 is rotatably mounted on the inner hollow cylindrical body 4 by means of bearings 5. The bearings (pivot bearings) 5 are designed as rolling bearings in the illustrated embodiment. The inner hollow cylindrical body 4 has a first central axis (X 1 ), while the outer hollow cylindrical body 3 has a second central axis (X 2 ) that coincides with, i.e., corresponds to, the first central axis (X 1 ).

[0053] A joint body 6 is provided to support the inner hollow cylindrical body 4 on the central axis 7, which defines a central axis X 3 . The joint body 6 is only schematically sketched in the drawing. The joint body 6 is mounted on the central axis 7 and preferably axially fixed. The joint body 6 is designed, for example, as a rubber body or rubber bearing. The inner hollow cylindrical body 4 sits on the joint body 6, with the body 4 being supported by its inner surface on the joint body 6. The hollow cylindrical body 4 is preferably firmly connected to a peripheral portion of the joint body 6, for example by means of a screw connection. The axial extent of the joint body 6 is significantly smaller than the axial extent of the body 4, with the joint body 6 being arranged centrally within the body 4. Accordingly, the ends of the hollow cylindrical body 4 project beyond the joint body 6.The articulated mounting of the hollow cylindrical body 4 on the central axis 7 enables a horizontal rotation of the hollow cylindrical bodies 3, 4 with their central axes X 1 , X 2 relative to the central axis 7 and their central axis X 3 . Independently of this, the articulated mounting of the hollow cylindrical body 4 on the central axis 7 also enables a (vertical) inclination of the hollow cylindrical bodies 3, 4 with their central axes X 1 , X 2 relative to the central axis 7 and their central axis X 3 . In other words, the articulated mounting of the hollow cylindrical body 4 on the central axis 7 by means of the articulated body 6 enables a horizontal and / or vertical change in angle between the central axes X 1 , X 2 of the hollow cylindrical bodies 3, 4 and the central axis X 3 of the central axis 7 (see . Fig. 1 and Fig. 2 ).

[0054] To detect this angular change, which is associated with a control intervention of the device, at least one sensor unit 9 or a measuring and evaluation system 8, which has at least one sensor unit 9, is arranged within the guide unit 2. If the device is mounted within a system, the central axis 7 is mounted at two positions by means of lateral brackets 10. In the Figures 1 and 2 the horizontal direction is marked with x and the direction perpendicular to it of the axial extension of the device 1 is marked with z.

[0055] Deviating from the provisions of the Figures 1 and 2 In the exemplary embodiment shown, the evaluation system 8 can also be arranged or fastened outside the guide unit 2, for example on one of the holders 10, wherein the at least one sensor unit 9 arranged within the guide unit 2 is connected to the evaluation system 8 via a measuring or data cable.

[0056] The sensor unit 9 of the measuring and evaluation system 8 is designed as an inductive or magnetic distance sensor, e.g., a Hall sensor, as an example of a sensor unit based on a contactless measuring principle. The arrangement shown enables indirect detection of the angular change by measuring the distance between the inner cylinder surface 4.1 of the inner hollow cylindrical body 4 and the lateral surface or outer side 7.1 of the central axis 7. Since the distance between the axial position of the measuring and evaluation system 8 on the central axis X3 and a second axial position spaced from this position, again on the central axis X3 of the central axis, is known, the angular change can be detected and determined by the measuring and evaluation system 8 from the distances measured before and during the control intervention, or during and after the control intervention.The said second axial position can, for example, be defined by the joint center point of the joint body, wherein the first axial position of the sensor unit 9 is axially spaced from the second position on the center axis Z 3 of the central axis 7.

[0057] For storing detected angle changes and / or for comparing detected angle changes with stored angle changes, the measuring and evaluation system 8 has a storage and computing unit 11 in the form of a single-board computer, which is arranged entirely within the measuring and evaluation system 8. Alternatively, the storage and computing unit 11 can also be arranged outside the guide unit 2 and connected to the measuring and evaluation system 8 via a data cable.

[0058] The power supply to the measuring and evaluation system 8 is provided, for example, via a voltage source 12 arranged within the system in the form of a rechargeable battery. The capacity of the battery is designed such that the measuring and evaluation system 8 can be supplied solely by the voltage source 12 for a certain period of time, for example, for a period of at least several weeks or months. For a power supply extending beyond this period, a generator can be arranged within the control unit 2. Supply electronics 14 arranged within the control unit, which can also be connected to an optionally available power generator, enables contactless power supply to the measuring and evaluation system 8 and the voltage source 12.

[0059] Alternatively or in addition to a power supply via a battery 12 and / or a generator, it is also within the scope of the invention to supply the measuring and evaluation system 8 and / or the at least one sensor unit 9 with electrical energy via supply cables (not shown) from an external power source (not shown). It is also within the scope of the invention to connect the measuring and evaluation system 8 to an external system control or monitoring device, for example, a control room, via data cables or signal lines.

[0060] The measurement and evaluation system 8 also has an interface unit 15 that enables a wireless signal connection to an external receiver. For example, the wireless signal connection is based on a local radio network according to the IEEE 802.11 standard. Via this connection, the angle changes recorded and / or stored by the measurement and evaluation system 8 can be sent to an external receiver, and angle changes can be received from an external data source, which are to be stored in the storage and processing unit 15.

[0061] To improve the measurement signal of the sensor element 8, a signal amplification element 16 can be arranged on a section of the inner surface 4.1 of the hollow cylindrical body 4. The signal amplification element 11, which is preferably made essentially of iron, is designed in a band-shaped manner, so that during a rotation of the outer hollow cylindrical body 3, at least a portion of the signal amplification element 11 always lies in the measuring direction of the sensor element 8 and the distance between the sensor element 8 and the inner surface 4.1 can be reliably measured by the inductive sensor element 8 for the indirect detection of the angular change.

[0062] In the area of ​​a first end 3.3 and in the area of ​​a second end 3.4 of the outer hollow cylindrical body 3, sealing elements 17 in the form of brush seals are arranged to prevent the entry of dirt into the guide unit and are connected to the inner surface 3.1 of the body 3, wherein the bristles forming the brush of the brush seal, which are made of flexible material, are directed radially inwards and, in a non-deflected state of the guide unit 2, delimit a minimal air gap between the sealing elements 17 and the central axis 7. In the case of a control intervention, as in Fig. 2 As shown using the example of a rotation of the hollow cylindrical bodies 3, 4 relative to the central axis 7, the flexible design of the sealing elements 17 ensures the sealing effect without any significant impairment of a control intervention, wherein the bristles are partially elastically deformed (cf. Fig. 2). Alternatively or in addition to these brush seals, the sealing elements 17 can be designed as spring bellows (rubber bellows) (cf. Fig. 5 to 7 ).

[0063] All components of the Fig. 3The measuring and evaluation system 8 shown is arranged, for example, in a substantially annular housing 8.1, wherein the housing 8.1 has a central receptacle 8.2 which is slightly larger than the diameter of the central axis 7, so that the measuring and evaluation system 8 can be pushed onto the central axis 7 and mounted thereon. The radial dimension of the housing 8.1 is adapted to the inner diameter of the hollow cylindrical body 4, so that the measuring and evaluation system 8 can be arranged within the body 4. In addition to the sensor unit 9, the measuring and evaluation system 8 can have a second sensor unit 9 which is arranged such that the measuring direction of the second sensor unit 9 is offset by approximately90°, so that the first sensor unit 9 can be used to detect a horizontal rotation of the hollow cylindrical bodies 3, 4 relative to the central axis 7, while the second sensor unit 9 can be used to detect an inclination of the hollow cylindrical bodies 3, 4 relative to the central axis 7. A stabilizer that supports the alignment of the housing 8.1 can be integrated into the measuring and evaluation system 8 so that the measuring directions of the first sensor element 9 and the second sensor element 9 are oriented accordingly when the measuring and evaluation system 8 is pushed onto the central axis 7.

[0064] In Fig. 4a system for monitoring and guiding a conveyor belt is shown, which comprises the device 1 described above and a recording unit 18. The recording unit 18 has a communication or connection module 19 for a radio-based connection to the measuring and evaluation system 8. This signal connection makes it possible to send the angular changes recorded by the measuring and evaluation system 8 during the duration of the connection and / or the data stored in the storage and computing unit 11 of the measuring and evaluation system 8 to the recording unit 18 and / or to transfer one or more angular changes required for comparison within the storage and computing unit 11 to the storage and computing unit 11.

[0065] The recording unit 18 is equipped with an optical signaling device 20, which has a red lamp 20.1, a yellow lamp 20.2, and a green lamp 20.3. In the illustrated embodiment, an activation signal for activating the signaling device 20 is provided by the storage and processing unit 11 of the measuring and evaluation system 8 (see FIG. Figures 1 and 2). The activation signal is modulated in such a way that in a normal operating state of the belt conveyor, in which no deviating control behavior of the guide unit 2 occurs, the green light 20.3 emits a constant light. In the event of deviating control behavior, the activation signal causes a periodic emission of light by the yellow light 20.2, whereby the frequency of the light signal can be used as an indicator for the cause of the deviating control behavior. For example, in the case of influences that have little influence on the control behavior, such as slightly dirty support rollers or suboptimal belt connections, the yellow light 20.2 emits light at a comparatively low frequency. The emission of light by the red light 20.1 characterizes a control behavior that indicates causes which, if not remedied, experience has shown will result in an imminent failure of the conveyor belt.Additionally, the recording unit 18 can include an acoustic signaling device 21 comprising a sound transducer as well as control and transducer elements. The acoustic signaling device 21 emits one or more signal tones depending on the activation signal.

[0066] An evaluation unit 22 integrated into the recording unit 18 has a storage and computing unit corresponding to the storage and computing unit 11 of the measuring and evaluation system 8, which provides the same functionality. In the event of a failure of the storage and computing unit 11 of the measuring and evaluation system 8, the storage and computing unit of the evaluation unit 22 generates an activation signal for the optical and / or acoustic signaling device 20, 21 so that the failure can be indicated. The recording unit 18 shown further comprises a display unit 23 in the form of an LCD display. A numerical code is displayed on this display unit 23, which indicates the operating state or control behavior of the control unit 2. If an operating state deviates from normal operation, a numerical code indicating the cause is displayed.

[0067] The Figures 5 and 6The embodiment of the device according to the invention shown differs from that shown in the Figures 1 and 2 The embodiment shown differs only in the design of the sealing elements 17. Instead of sealing elements 17 in the form of brush seals, the Figures 5 and 6The device shown has sealing elements 17 in the form of spring bellows (also called rubber bellows). The spring bellows 17' are each sealingly connected to the inner hollow cylindrical body 4, preferably to its outer surface 4.2, and the central axis 7. The spring bellows 17' are preferably designed such that they seal off rotary bearings 5, for example, roller bearings, arranged between the outer hollow cylindrical body 3 and the inner hollow cylindrical body 4 from the ingress of dirt. The spring bellows 17' thus prevent or reduce the ingress of foreign material, for example, dust-like foreign material, into the guide unit 2.

[0068] The Fig. 7 The embodiment of the device according to the invention shown differs from that shown in the Figures 5 and 6 The exemplary embodiment outlined only relates to the design of the measuring and evaluation system 8. In the Fig. 7In the example outlined, at least one sensor unit 9 and an evaluation unit 8' of the measuring and evaluation system 8 are arranged at a distance from one another. While the at least one sensor unit 9 is arranged within the guide unit 2, for example within the inner hollow cylindrical body 4, and shielded by the bellows 17', the evaluation unit 8' is located outside the hollow cylindrical body 3. For example, the evaluation unit 8' is mounted between the end 3.4 of the hollow cylindrical body 3 and one of the holders 10 on the central axis 7. In this case, the sensor unit 9 is connected to the evaluation unit 8', for example, via a signal line 30. Optionally, the sensor unit 9 and / or the evaluation unit 8' can be connected to one or the above-mentioned supply electronics 14 via a supply line 31.

[0069] In Fig. 8Two further embodiments or variants of the device 1 according to the invention are shown. In one of these variants, which is shown in the area of ​​the left end of the device 1, at least one sensor unit 9' and an evaluation unit 8' of the measuring and evaluation system 8 are arranged at a distance from one another. While the at least one sensor unit 9' is arranged within the guide unit 2, specifically within the outer hollow cylindrical body 3, but outside the inner hollow cylindrical body 4, the evaluation unit 8' is located outside the hollow cylindrical body 3. The sensor unit 9' is protected against contamination by sealing elements 17 in the form of brush seals. The evaluation unit 8' is mounted between the end 3.4 of the hollow cylindrical body 3 and one of the holders 10 on the central axis 7.In this case, the sensor unit 9' is connected to the evaluation unit 8', for example, via a signal line 30. Optionally, the sensor unit 9' and / or the evaluation unit 8' can be connected to one of the above-mentioned supply electronics 14 via a supply line 31. As an alternative to the arrangement shown in . Fig. 8 In addition to the arrangement or mounting on the central axis 7 shown, the evaluation unit 8' can also be mounted on one of the brackets 10.

[0070] At the same time, Fig. 8 in the area of ​​the right end of the device 1, a variant in which the at least one sensor unit 9 and the evaluation unit are designed together as a compact measuring and evaluation system 8. In this embodiment, however, the measuring and evaluation system 8 is, in contrast to the Figures 1 and 2In the embodiment shown, the measuring and evaluation system 8 is not arranged inside, but outside the inner hollow cylindrical body 4 and inside the outer hollow cylindrical body 3, wherein the measuring and evaluation system 8 is in turn protected against contamination by sealing elements 17 in the form of brush seals. Fig. 8 To avoid repetition, reference is made to the above description of the Figures 1 and 2 referred to.

[0071] In the Figures 9a to 9c A further embodiment of the device 1 according to the invention is shown. This embodiment differs from the Figures 1 to 7shown embodiments with regard to the design and arrangement of the measuring and evaluation system. The measuring and evaluation system is arranged outside the inner hollow cylindrical body 4, which can also be referred to as the inner tube. The at least one sensor unit 9" and the evaluation unit 8' of the measuring and evaluation system are arranged at a distance from one another. A sensor holder 9.1 is plugged onto one end of the inner hollow cylindrical body (inner tube) 4 and is preferably connected to the body 4 in a force-fitting or friction-fitting manner. The sensor holder 9.1 is bush-shaped and is preferably connected to the outer surface 4.2 of the inner hollow cylindrical body 4. The bush or the sensor holder 9.1 is made of plastic, for example. A sealing element 17', preferably in the form of a spring or rubber bellows, is in turn connected to the bush or the sensor holder 9.1.The sealing element 17' is connected to the central axis 7 and seals the interior of the hollow cylindrical body 4 against the ingress of dirt and dust. At least one sensor unit 9" of the measuring and evaluation system is installed on the sensor holder 9.1. For example, the sensor holder 9.1 is provided with four sensor units (sensors) 9" that are distributed over the circumference of the bush-shaped sensor holder 9.1 and arranged at a distance from one another. The sensor units 9" measure contactlessly in the direction of the central axis 7. The sensor measurement on the outer side 7.1 of the central axis 7 is protected from dust by the sealing element 17'. In addition, at least part of the supply electronics 14 is also arranged on the sensor holder 9.1. Fig. 9In the embodiment shown, mutually associated elements 14.1, 14.2 of a generator system of the supply electronics 14 are arranged on the outer surface of the sensor holder 9.1 or on the inner surface 3.1 of the outer hollow cylindrical body 3 ( Fig. 9b ). The elements 14.1, 14.2 of the supply electronics 14 are arranged axially offset to the sensor units 9" ( Fig. 9c ). The evaluation unit 8' is mounted outside the outer hollow cylindrical body 3 of the guide unit 2 on one of the brackets 10 ( Fig. 9a ). Accordingly, the sensor units 9" and the supply electronics 14 are connected to the evaluation unit 8' via signal and supply lines 30, for example in the form of one or more cables. With regard to the Fig. 9a In order to avoid repetition, reference is made to the above description of the Figures 1 and 2 referred to.

[0072] The Figures 10a and10b show a further embodiment of the device 1 according to the invention. In contrast to the device shown in the Fig. 9a to 9cIn the embodiment shown, the measuring technology in this case is not arranged on the inner hollow cylindrical body 4 and thus within the outer hollow cylindrical body (outer tube) 3, but at the end of the outer body 3 and thus essentially or largely outside the outer body 3. A sensor holder 9.1' is mounted on the central axis 7 and is preferably connected to the central axis 7 in a force-locking or friction-locking manner. The sensor holder 9.1' is bush-shaped. For example, the sensor holder 9.1' is provided with four sensor units (sensors) 9", which are distributed over the circumference of the bush-shaped sensor holder 9.1 and arranged at a distance from one another. The sensor units 9" measure without contact in the direction of an annular or bush-shaped body 33, which surrounds the sensor holder 9.1' at a radial distance and is preferably connected to the end of the outer hollow cylindrical body 3 in a rotationally fixed manner.For this purpose, the ring- or bush-shaped body 33 has a connecting section 33.1 which is inserted into the outer tube 3 in a force- or friction-locking manner. The body 33 assigned to the sensor units (sensors) 9" can also be referred to as a reflector body. The sensor units 9" are connected to the evaluation unit 8' via signal lines 30, for example in the form of one or more cables. With regard to the in . Fig. 10a and 10b In order to avoid repetition, reference is made to the above description of the Figures 1 , 2 and 9a to 9c referred to.

[0073] The implementation of the invention is not limited to the exemplary embodiments illustrated in the drawings. Rather, numerous variants are conceivable, which, even with a design that deviates from the examples shown, make use of the invention defined in the appended claims. For example, it is also within the scope of the invention for the at least one sensor unit 9 or the measuring and evaluation system 8 to be arranged on the central axis 7 outside the inner hollow cylindrical body 4 and inside the outer hollow cylindrical body 3.

Claims

1. Device (1) for guiding a conveyor belt, having a guide unit (2) with an outer and an inner hollow-cylindrical body (3, 4), the inner hollow-cylindrical body (4) having a first central axis and being arranged in the outer hollow-cylindrical body (3), which has a second central axis, and both hollow-cylindrical bodies (3, 4) each have a central axis (X1, X2), with at least one bearing (5) for rotatably mounting the outer hollow-cylindrical body (3) on the inner hollow-cylindrical body (4) and with an articulation body (6) designed for mounting the inner hollow-cylindrical body (4) on a central axle (7), wherein the articulation body (6) is further designed to allow a horizontal and / or vertical change in angle of the first and / or second central axis (X1, X2) relative to a central axis (Xa) of the central axle (7), characterized by a measuring and evaluating system (8) comprising at least one sensor unit (9, 9', 9") arranged inside and / or outside the guide unit (2), wherein the measuring and evaluating system (8) is designed to detect the change in angle.

2. Device according to claim 1, characterized in that the measuring and evaluation system (8) has at least a second sensor unit (9, 9', 9"), the second sensor unit (9, 9', 9") being arranged inside the guide unit (2).

3. Device according to claim 1 or 2, characterized in that the respective sensor unit (9, 9', 9") is a sensor unit (9, 9', 9") based on a contactless measuring principle.

4. Device according to any one of claims 1 to 3, characterized in that the measuring and evaluation system (8) comprises at least one memory and computing unit (11), wherein the memory and computing unit (11) is designed to store detected changes in angle and / or to compare a detected change in angle with stored changes in angle.

5. Device according to any one of claims 1 to 4, characterized in that a voltage source (12), preferably a rechargeable voltage source (12), is arranged within the guide unit (2), the voltage source (12) being designed to supply the at least one measuring and evaluation system (8).

6. Device according to any one of claims 1 to 5, characterized in that an electronic supply (14) is arranged within the guide unit (2), the electronic supply (14) being designed for contactless supply of the measuring and evaluation system (8) and / or the voltage source (12).

7. Device according to any one of claims 1 to 6, characterized in that the measuring and evaluation system (8) has an interface unit (15) which is designed for a wireless signal connection.

8. Device according to any one of claims 1 to 7, characterized in that sealing elements (17, 17') are arranged inside the guide unit (2), preferably in the region of a first end (3.3) and in the region of a second end (3.4) of the outer hollow-cylindrical body (3).

9. Device according to any one of claims 1 to 8, characterized in that the measuring and evaluation system (8) is mounted on the central axle (7) or on the inner hollow-cylindrical body (4), preferably pushed onto the central axle (7) or plugged onto the inner hollow-cylindrical body (4).

10. System for monitoring and guiding a conveyor belt with a device according to any one of claims 1 to 9 and a recording unit (18), wherein the recording unit (18) is designed for a signal connection with the measuring and evaluation system (8).

11. System according to claim 10, characterized in that the recording unit (18) comprises an optical signaling device (20) and / or is designed for connection to an optical signaling device (20).

12. System according to claim 10 or 11, characterized in that the recording unit (18) comprises an acoustic signaling device (21) and / or is designed for connection to an acoustic signaling device (21).

13. System according to any one of claims 10 to 12, characterized in that the recording unit (18) comprises an evaluation unit (22) and / or a display unit (23), wherein the evaluation unit (22) has at least one memory and computing unit and wherein the memory and computing unit is designed for storing detected changes in angle and / or for comparing a detected change in angle with stored changes in angle.

14. System according to any one of claims 10 to 13, characterized in that the recording unit (18) is designed as a hand-held device.

15. System according to any one of claims 10 to 14, characterized in that the conveyor belt has a marker or is provided with a marker, the system comprising a sensor for determining a measuring period and / or circulation time of the marker.