Monitoring system for monitoring parameters representing operating conditions of a hydrodynamic bearing

Abstract

A system for monitoring parameters representative of operating conditions of an oil film bearing, in which an oil film is arranged between a stationary component 2 defining an axis X and at least one rotating component 3, 4, the at least one rotating component being arranged inside the stationary component 2, the system comprising at least one pressure sensor 5 for detecting the oil pressure of the oil film, at least one distance sensor 8 for detecting the thickness of the oil film and at least one temperature sensor 9 for detecting the temperature of the oil film, the at least one pressure sensor 5, the at least one distance sensor 8 and the at least one temperature sensor 9 being accommodated in the at least one rotating component 3, 4.

Description

Technical Field

[0001] The present invention relates to a monitoring system for oil film bearings, which is provided, for example, in a rolling mill stand or a roll casting apparatus or a coil forming system.

Background Art

[0002] In a rolling mill stand for steel sheets and steel strips, and in other similar applications (for example, a continuous roll casting apparatus, a shaped product rolling mill, a coil forming system), the rolls are supported by bearings.

[0003] One of the main techniques used for these bearings is a solution using an oil film, and most frequently a shaft covered by a replaceable sleeve rotates inside a stationary bushing.

[0004] To limit friction and wear between components, an amount of oil is injected between the bushing and the sleeve to create an oil layer that can reduce or almost eliminate friction and prevent strong contact between two relatively moving components.

[0005] In principle, it is understood that there is no friction and wear in this rotation and the shaft is coaxial with the bushing acting as a guiding element. In practice, friction and wear are minimized but still exist, and deformation of the shaft and related displacements with respect to the bushing may occur, determining the operating conditions that cause wear of the components. Furthermore, due to these conditions, non-uniform distances, pressure peaks, and heating of the oil can occur between the shaft and the bushing. Therefore, the temperature, pressure, and thickness of the oil film vary in the gap between the two components depending on the load, rotational speed, and other operating conditions.

[0006] Currently, these conditions are mainly predicted by some approximation using theoretical or empirical models, and their evaluation makes it possible to estimate the load on the components, the remaining wear, and the bearing life.

[0007] Unfortunately, the level of prediction, due not only to the low accuracy of the prediction but also to the variability of the operating conditions, is not sufficient to anticipate premature and sporadic defects or to determine the actually achievable performance.

[0008] Having the ability to estimate oil film operating conditions in the art has the beneficial effect of reducing uncertainty, enabling improved prediction accuracy, eliminating uncertainty regarding actual operating conditions, improving bearing performance and life, and improving the execution of operation to optimize bearing behavior.

Summary of the Invention

Problems to be Solved by the Invention

[0009] Therefore, there is a perceived need to create a monitoring system for the operating conditions of a hydrodynamic bearing that can overcome the aforementioned drawbacks.

Means for Solving the Problems

[0010] An object of the present invention is to create a novel solution for more effective monitoring of operating conditions in a hydrodynamic bearing.

[0011] A further object of the present invention is to provide a monitoring system that enables continuous monitoring of the pressure, temperature, and layer thickness of the lubricating oil injected between the shaft and the bushing, or between the shaft sleeve and the bushing, which are three parameters specific to the hydrodynamic bearing.

[0012] The present invention achieves these and other objects, which will become apparent in light of the present specification, and is a system for monitoring parameters representing the operating conditions of a hydrodynamic bearing according to claim 1, in which there is an oil film between a stationary component and at least one rotating component that together define an axis, and at least one rotating component is disposed inside the stationary component, comprising: - at least one pressure sensor for detecting the oil pressure of the oil film; - At least one distance sensor for detecting the distance between a stationary component and at least one rotating component and thereby for detecting the thickness of the oil film, - At least one temperature sensor for detecting the temperature of the oil film comprising At least one pressure sensor, at least one distance sensor, and at least one temperature sensor are housed in at least one rotating component, by a monitoring system.

[0013] Thus, the solution enables mapping of the three main parameters: oil film temperature, oil film thickness, and oil pressure.

[0014] Advantageously, the three types of sensors are installed on the rotating shaft or on a sleeve attached to the rotating shaft instead of the stationary housing.

[0015] Since the sensor can rotate with the rotating component, it is advantageous that the aforementioned three parameters of the oil film can be measured in different regions and mapping can be achieved.

[0016] According to the solution of the present invention, these three parameters are measured for each point of the oil film that is spaced along one or more circumferences having a substantial center on the axis X, in particular along the width of the bearing (parallel to the axis X, FIG. 1), enabling an accurate reproduction of the actual operating conditions. In addition, it can enable an accurate reproduction of the possible deformation of the shaft inside the bearing, which often has an unpredictable but clearly affects the local stress on the mechanical components and can cause damage and wear.

[0017] The following three types of sensors can be used, for example, to simultaneously measure the temperature, pressure, and thickness of the oil film. - A set of pressure sensors, such as piezoresistive sensors or other suitable sensors, capable of generating an electrical signal based on the applied pressure. - A set of temperature sensors, such as thermocouples or other suitable sensors, capable of creating an electrical signal based on the measured temperature. - A set of distance sensors, such as inductive sensors or other suitable sensors, capable of reading the distance between the bushing and the sleeve or the distance between the bushing and the shaft when there is an oil gap between them.

[0018] The monitoring system according to the present invention has a small number of sensors installed at the stationary part of the bearing to simplify the power supply to them, and unlike other possible monitoring systems where the sensors monitor only one of the above-mentioned parameters, it is advantageous to be able to obtain an accurate mapping of the above three parameters at high resolution using a small number of sensors.

[0019] Instead, in the present invention, the sensors are mounted directly on the sleeve if the sleeve exists, or directly on the shaft, so that, for example, for each type of sensor, a single row of sensors having two or more sensors can be installed at appropriate intervals in the axial direction. Thus, a regular measurement grid is obtained by the rotation applied to the shaft.

[0020] Alternatively, only one sensor may be provided for each type of sensor.

[0021] The sensors can be powered by sliding contacts, batteries, wirelessly, or otherwise, such as by a device equipped with an alternator and a flywheel. In this way, existing equipment can also be adjusted without requiring complex technical interventions.

[0022] Some advantages of the solution of the present invention over the prior art are listed below. - Efficient monitoring of the operating conditions of the bearing. - Anticipating possible accidents and thus being able to reduce accidents. - If the measured conditions are good, it is possible to operate the bearing beyond the conventional operating time. - Cost reduction. - The ability to independently monitor the aforementioned three parameters. - The ability to be installed on existing machines without generating a new burden.

[0023] The present invention further relates to a rolling mill stand according to claim 11, a continuous roll casting apparatus according to claim 12, and a coil forming system according to claim 13.

[0024] Further features and advantages of the present invention will become more apparent in light of the detailed description of the preferred but non-exclusive embodiments.

[0025] The dependent claims describe specific embodiments of the present invention.

[0026] The description of the present invention refers to the accompanying drawings, which are provided as non-limiting examples.

Brief Description of the Drawings

[0027]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0028] The same elements or components are referred to using the same reference numerals.

[0029] Exemplary embodiments of the monitoring system according to the present invention are described with reference to the drawings.

[0030] The monitoring system can be advantageously used, and in particular can be implemented, in, for example, a rolling mill stand, a continuous roll casting apparatus, or a coil forming system.

[0031] The monitoring system is used in particular to monitor parameters representing the operating conditions of a hydrodynamic bearing, in which a hydrodynamic film is arranged between a stationary component 2 defining an axis X and at least one rotating component 3, 4, and in which at least one rotating component 3, 4 is arranged inside the stationary component 2.

[0032] The term "rotating component" refers in particular to a component that can rotate, i.e. a rotatable component. More particularly, the component is capable of rotating around the axis X.

[0033] The term "stationary component" means in particular a component that is fixed in position, especially during the rotation of the rotating component.

[0034] In all embodiments, the monitoring system - at least one pressure sensor 5 for detecting the hydraulic pressure of the hydrodynamic film, and - at least one distance sensor 8 for detecting the distance between the stationary component 2 and at least one rotating component 3, 4 and thus for detecting the thickness of the hydrodynamic film, and - at least one temperature sensor 9 for detecting the temperature of the hydrodynamic film is provided.

[0035] Advantageously, at least one pressure sensor 5, at least one distance sensor 8, and at least one temperature sensor 9 are accommodated in at least one rotating component 3, 4.

[0036] In particular, at least one pressure sensor 5, at least one distance sensor 8, and at least one temperature sensor 9 are accommodated in at least one rotatable component 3, 4 so as to be able to rotate with at least one rotatable component 3, 4, for example so as to be able to rotate integrally with at least one rotatable component 3, 4.

[0037] When each of the sensors 5, 8, and 9 rotates once around the axis X, it is advantageous that measured values of the parameters detected by the sensors can be obtained along the circumference along which the sensors have moved. Therefore, it is advantageous that each of the sensors 5, 8, and 9 can detect their respective parameters at different angular positions.

[0038] Preferably, each of the sensors 5, 8, and 9 is arranged in the peripheral region of the rotating components 3, 4.

[0039] Although not exclusive but preferably, the parts of each of the sensors 5, 8, and 9 define parts of the peripheral portions of the rotating components 3, 4. The peripheral portions of the rotating components 3, 4 are the parts of the rotating components 3, 4 proximal to the stationary component 2.

[0040] At least one pressure sensor 5, at least one distance sensor 8, and at least one temperature sensor 9 are preferably arranged in one or more holes or cavities of at least one of the rotating components 3, 4.

[0041] Preferably, each hole or cavity is properly plugged to prevent unwanted oil ingress. For example, each hole or cavity can be plugged by each of the sensors 5, 8, 9 and / or by sealing means.

[0042] In particular, the walls delimiting each hole or cavity extend around their respective axis J (one of which is shown in FIG. 1), and the axis J preferably intersects the axis X. Preferably, the axes J of the holes or cavities are parallel to each other. In a first variant, the axis J of the hole or cavity is perpendicular to the axis X, whereby the sensors are arranged radially with respect to the axis X.

[0043] In a second variant, each of the axes J of the holes or cavities makes an angle other than 90° with respect to the axis X, whereby the sensors are not arranged radially with respect to the axis X.

[0044] Preferably, at least one pressure sensor 5 is housed in a first hole or cavity obtained in at least one of the rotating components 3, 4, at least one distance sensor 8 is housed in a second hole or cavity obtained in at least one of the rotating components 3, 4, and at least one temperature sensor 9 is housed in a third hole or cavity obtained in at least one of the rotating components 3, 4. In particular, the first hole or cavity, the second hole or cavity, and the third hole or cavity are separate from each other.

[0045] Alternatively, any two of at least one pressure sensor 5, at least one distance sensor 8, or at least one temperature sensor 9 are housed in a first hole or cavity obtained in at least one of the rotating components 3, 4, and the other one is housed in a second hole or cavity obtained in at least one of the rotating components 3, 4. For example, one or more pressure sensors 5 and one or more distance sensors 8 are housed in the first hole or cavity, and one or more temperature sensors 9 are housed in the second hole or cavity.

[0046] Alternatively, at least one pressure sensor 5, at least one distance sensor 8, and at least one temperature sensor 9 are housed in a single hole or cavity obtained in at least one of the rotating components 3, 4. For example, the pressure sensor 5, the distance sensor 8, and the temperature sensor 9 can be arranged in the same hole or cavity. For example, it is possible to provide two or more holes or cavities, and each of them houses the pressure sensor 5, the distance sensor 8, and the temperature sensor 9.

[0047] Preferably, two or more pressure sensors 5, two or more distance sensors 8, and two or more temperature sensors 9 are provided.

[0048] Preferably, two or more pressure sensors 5 are axially spaced from each other with respect to the axis X, and / or two or more distance sensors 8 are axially spaced from each other with respect to the axis X, and / or two or more temperature sensors 9 are axially spaced from each other with respect to the axis X.

[0049] Preferably, a column of pressure sensors 5, a column of distance sensors 8, and a column of temperature sensors 9 are provided, and each column is arranged along a direction parallel to the axis X.

[0050] In other words, two or more pressure sensors 5 are arranged so as to form a column. In particular, two or more pressure sensors 5 are aligned with each other along a direction particularly parallel to the axis X. The same applies to the distance sensors 8 and the temperature sensors 9.

[0051] Thus, it is advantageous that three types of parameters can be measured at different positions along the axis X.

[0052] Preferably, the column of pressure sensors 5, the column of distance sensors 8, and the column of temperature sensors 9 are arranged along the periphery of at least one of the rotating components 3, 4, preferably in a region corresponding to the central angle of the convex corner.

[0053] Preferably, the pressure sensors 5 are equidistant from each other, the distance sensors 8 are equidistant from each other, and the temperature sensors 9 are equidistant from each other.

[0054] In a preferred variant, the distance between one pressure sensor 5 and the next one is equal to both the distance between one distance sensor 8 and the next one and the distance between one temperature sensor 9 and the next one.

[0055] Preferably, each triple consisting of a pressure sensor 5, a distance sensor 8, and a temperature sensor 9 is arranged along a portion of a circumference having its center on the axis X.

[0056] However, preferably in a region corresponding to the central angle of the convex corner, particularly along the periphery of at least one of the rotating components 3, 4, one single pressure sensor 5, one single distance sensor 8, and one single temperature sensor 9 may be provided. Preferably, this single triple of sensors 5, 8, 9 is arranged along a portion of a circumference having its center on the axis X.

[0057] In all embodiments, at least one pressure sensor 5, at least one distance sensor 8, and at least one temperature sensor 9 are connected to the digitizing device 7 by their respective cables 6, in particular electrical cables. The digitizing device 7 is configured to digitize the signals generated by the respective sensors 5, 8, 9. Preferably, the digitizing device 7 is adapted to transmit the digitized signals by means of a rotary joint or wirelessly.

[0058] The digitizing device 7 preferably comprises a housing that includes electronic hardware capable of amplifying and converting, in particular digitizing, the signals of the sensors 5, 8, 9.

[0059] The digitizing device 7, in particular its housing, is preferably mounted on the rotating components 3, 4, in particular on the rotating component 4, which is, for example, a shaft pin. More particularly, the digitizing device 7 is preferably fixed to the rotating component 4, such that the digitizing device 7 can rotate therewith, for example integrally therewith.

[0060] Preferably, the digitizing device 7 is fixed to the axial end (axial with respect to the axis X) of the rotating component 4. Preferably, the digitizing device 7 is arranged so as to cross the axis X.

[0061] In all embodiments, at least one pressure sensor 5, at least one distance sensor 8, and at least one temperature sensor 9 can be powered by means of a sliding contact, a battery, wirelessly, or a device provided with an alternator and a flywheel.

[0062] In particular, the device is fixed to the rotating component 4, such that the device can rotate integrally therewith. The rotating component 4 and the device are arranged coaxially (with respect to the axis X) with respect to each other.

[0063] When the rotating component 4 rotates around the axis X, the flywheel is rotated and, when rotating, generates energy by means of an alternator. In this way, the sensors 5, 8, 9 can be supplied with power without the need for a battery.

[0064] The stationary component 2 is, for example, a bushing 2.

[0065] At least one of the rotating components 3, 4 consists, for example, of a shaft pin 4 (or end pin), or a sleeve 3 into which the shaft pin 4 is inserted.

[0066] The shaft pin 4 is, for example, the neck or pin of a roll 11 of a rolling mill stand or a continuous casting plant or a coil forming system.

[0067] In the illustrated example, the sensors 5, 8, 9 are accommodated in the sleeve 3. An oil film is present between the sleeve 3 and the bushing 2. In particular, the oil film contacts the sleeve 3 and the bushing 2. Preferably, the surfaces of the sleeve 3 and the bushing 2 between which the oil film is present are cylindrical or substantially cylindrical.

[0068] The pin, in particular the shaft pin 4 or the end pin, is inserted into the sleeve 3.

[0069] Preferably, the sleeve 3 is arranged around the part of the shaft pin 4 whose outer surface tapers, for example is frustoconical. In this case, the inner surface of the sleeve 3 also tapers, in particular in the direction opposite to the direction in which the surface part of the shaft pin 4 tapers, for example is frustoconical. Preferably, the thickness of the sleeve wall 3 parallel to the axis Y increases outwards along the axis X. The axis Y is perpendicular to the axis X.

[0070] The shaft pin 4 is designed to rotate. The sleeve 3 and the shaft pin 4 are fixed to each other, in particular the sleeve 3 and the shaft pin 4 are designed to rotate integrally.

[0071] When sensors 5, 8, and 9 are housed in sleeve 3, the axis J of the hole or cavity is preferably perpendicular to axis X, whereby the sensors are arranged in the hole in a radial direction with respect to axis X.

[0072] If the maximum dimension of the sensors used exceeds the thickness of sleeve 3 along axis Y, the axis J (FIG. 1) of the hole or cavity is inclined to form an angle other than 90° with respect to axis X, so that it is preferred that the sensors are not arranged in a radial direction with respect to axis X. This solution enables modification of only sleeve 3 without changing shaft pin 4, whereby this solution can be applied in the case of retrofitting.

[0073] In an alternative example (not shown), sensors 5, 8, and 9 are housed in a rotating component 4, which is, for example, a pin, in particular shaft pin 4 or end pin 4. In particular, sleeve 3 is not provided. There is an oil film between shaft pin 4 and bushing 2. In particular, the oil film contacts shaft pin 4 and bushing 2. Here too, it is preferred that the axis J of the hole or cavity is perpendicular to axis X. However, the axis J of the hole or cavity can be inclined to form an angle other than 90° with respect to axis X.

[0074] FIG. 1 shows a part of roll 11. Roll 11 has a part that contacts the workpiece.

[0075] Roll 11 is provided with two shaft pins 4 or end pins 4, one of which is shown in FIG. 1. Shaft pin 4 is in particular the axial (with respect to axis X) end portion of roll 11. The aforementioned portion adapted to contact the material to be processed extends between the two shaft pins 4.

[0076] Each end pin 4 is supported by a respective chuck 1. The stationary component 2 is received in each chuck 1, in particular in the through hole of each chuck 1, and at least one rotating component 3, 4 crosses the inside.

[0077] For each roll 11, the monitoring system can be implemented for both sets of stationary components 2 and rotating components 3, 4 that are on opposite sides with respect to a plane perpendicular to axis X and in particular parallel to axis Y depicted in FIG. 1. The two monitoring systems implemented for each roll 11 preferably comprise the same components and are preferably arranged symmetrically with respect to the plane.

[0078] As described above, the present invention is a rolling mill stand, or a continuous roll casting apparatus, or a coil forming system in which each roll 11 has an end pin 4 supported by respective chucks 1, a stationary component 2 traversing the interior of at least one of the rotating components 3, 4 is received in a through-hole of each chuck 1, and the stationary component 2 and at least one of the rotating components 3, 4 define an axis X, an oil film is disposed between the stationary component 2 and at least one of the rotating components 3, 4, at least one of the rotating components 3, 4 consists of an end pin 4 of the respective roll 11, or a sleeve 3 into which the end pin 4 is inserted, a monitoring system for parameters representing the operating conditions of the oil film as described above is provided, and further relates to a rolling mill stand, or a continuous roll casting apparatus, or a coil forming system.

[0079] The rolling mill stand, the continuous roll casting apparatus, and the coil forming system each comprise one or more rolls 11.

Claims

1. There is an oil film (10) between a stationary component (2) and rotating components (3, 4) that both define axis X, and the rotating components (3, 4) are arranged inside the stationary component (2) and adapted to rotate around the axis X. A monitoring system for monitoring parameters representing the operating conditions of a hydrodynamic bearing, comprising: at least one pressure sensor (5) for detecting the oil pressure of the oil film; at least one distance sensor (8) for detecting the distance between the stationary component (2) and the rotating components (3, 4) and thereby detecting the thickness of the oil film; at least one temperature sensor (9) for detecting the temperature of the oil film; comprising; the at least one pressure sensor (5), the at least one distance sensor (8), and the at least one temperature sensor (9) are housed in the rotating components (3, 4); A monitoring system, characterized in that only one pressure sensor (5), only one distance sensor (8), and only one temperature sensor (9) are arranged along the periphery of the rotating components (3, 4) in a region corresponding to the central angle of the convex angle.

2. The at least one pressure sensor (5) is housed in a first hole or cavity obtained within the rotating components (3, 4), the at least one distance sensor (8) is housed in a second hole or cavity obtained within the rotating components (3, 4), and the at least one temperature sensor (9) is housed in a third hole or cavity obtained within the rotating components (3, 4), or Any two of the at least one pressure sensor (5), the at least one distance sensor (8), or the at least one temperature sensor (9) are housed in a first hole or cavity obtained within the rotating components (3, 4), and the other one is housed in a second hole or cavity obtained within the rotating components (3, 4), or The at least one pressure sensor (5), the at least one distance sensor (8), and the at least one temperature sensor (9) are housed in a single hole or cavity obtained within the rotating components (3, 4); The monitoring system according to claim 1.

3. The pressure sensor (5), the distance sensor (8), and the temperature sensor (9) are arranged along the same part of the circumference centered on the axis X. The monitoring system according to claim 1 or 2.

4. The at least one pressure sensor (5), the at least one distance sensor (8), and the at least one temperature sensor (9) are each connected by a respective cable (6) to a digitizing device (7) for digitizing the signals generated by the respective sensors, wherein the digitizing device (7) is adapted to transmit the digitized signals by means of a rotary joint or wirelessly. The monitoring system according to any one of claims 1 to 3.

5. The stationary component (2) is a bushing, and the rotating components (3, 4) consist of a shaft pin (4) or a sleeve (3) into which the shaft pin (4) is inserted. The monitoring system according to any one of claims 1 to 4.

6. The shaft pin (4) is a neck or pin of a roll (11) for use in a rolling mill stand or a continuous casting plant or a coil forming system. The monitoring system according to claim 5.

7. The at least one pressure sensor (5), the at least one distance sensor (8), and the at least one temperature sensor (9) are powered by a sliding contact, a battery, wirelessly, or a device provided with an alternator and a flywheel. The monitoring system according to any one of claims 1 to 6.

8. The at least one pressure sensor (5), the at least one distance sensor (8), and the at least one temperature sensor (9) are received in a hole or cavity defining an axis J that is inclined radially with respect to the axis X or at an angle other than 90° with respect to the axis X. The monitoring system according to any one of claims 1 to 7.

9. A rolling mill stand in which each roll (11) has an end pin (4) supported by a respective chuck (1), wherein a stationary component (2) crossing the interior of the rotating components (3, 4) is received in a through-hole of each chuck (1), and the stationary component (2) and the rotating components (3, 4) define an axis X, wherein an oil film is disposed between the stationary component (2) and the rotating components (3, 4), and the rotating components (3, 4) consist of an end pin (4) of each roll (11) or a sleeve (3) into which the end pin (4) is inserted. The monitoring system according to any one of claims 1 to 8 is provided for monitoring parameters representing the operating conditions of the oil film. Rolling mill stand.

10. A continuous roll casting apparatus in which each roll has an end pin (4) supported by a respective chuck (1), A stationary component (2) crossing inside the rotating components (3, 4) is received in a through-hole of each chuck (1), and the stationary component and the rotating components define an axis X. An oil film is disposed between the stationary component (2) and the rotating components (3, 4). The rotating components (3, 4) consist of the end pins (4) of the respective rolls (11) or sleeves (3) into which the end pins (4) are inserted. The monitoring system according to any one of claims 1 to 8 is provided for monitoring parameters representing the operating conditions of the oil film. Continuous roll casting apparatus.

11. A coil forming system in which each roll has an end pin (4) supported by a respective chuck (1), A stationary component (2) crossing inside the rotating components (3, 4) is received in a through-hole of each chuck (1), and the stationary component and the rotating components define an axis X. An oil film is disposed between the stationary component (2) and the rotating components (3, 4). The rotating components (3, 4) consist of the end pins (4) of the respective rolls (11) or sleeves (3) into which the end pins (4) are inserted. The monitoring system according to any one of claims 1 to 8 is provided for monitoring parameters representing the operating conditions of the oil film. Coil forming system.

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