Monitoring apparatus, system, and method for motion state of rolling bearing
Patent Information
- Application Number
- PCT/CN2026/086427
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-27
- Filing Date
- 2026-03-26
- Publication Date
- 2026-10-01
Smart Images
Figure CN2026086427_01102026_PF_FP_ABST
Abstract
Description
A device, system and method for monitoring the motion state of a rolling bearing
[0001] Cross-references to related applications
[0002] This application claims priority to Chinese Patent Application No. 202510375686.0, filed on March 27, 2025, entitled "A Monitoring Device, Monitoring System and Monitoring Method for the Motion State of a Rolling Bearing", the entire contents of which are incorporated herein by reference. Technical Field
[0003] This application relates to the field of sensor technology, and in particular to a device, system and method for monitoring the motion state of a rolling bearing. Background Technology
[0004] Rolling bearings, as core components in mechanical equipment, are widely used in mechanical systems such as servo motors, high-speed railways, wind turbines, and aero engines. Statistics show that rolling bearing failures account for approximately 44% of all mechanical equipment failures. Especially under high-speed operating conditions, the dynamic performance of rolling bearings directly affects the reliability of the equipment.
[0005] During the operation of rolling bearings, phenomena such as rolling element slippage and cage wear may occur. These problems lead to the accumulation of frictional heat, resulting in damage such as microcracks and fatigue spalling in the rolling bearing. Among these signs of failure, slippage is one of the important indicators for assessing the health of the bearing. Real-time monitoring of the rolling element speed and the presence of slippage is crucial for ensuring the normal operation of mechanical equipment.
[0006] However, existing monitoring technologies, such as eddy current sensing and weak magnetic field detection, suffer from limitations in installation and insufficient accuracy, making it difficult to achieve in-situ monitoring of multiple parameters. Furthermore, existing monitoring systems typically monitor the rotational speed of the rolling bearing cage, as this is relatively easy to measure. However, the cage's rotational speed does not always accurately reflect the actual rotational speed of the rolling elements. If bearing slippage occurs, the actual rotational speed of the rolling elements will differ from that of the cage. In such cases, simply monitoring the cage's rotational speed may not accurately determine whether the rolling elements are slipping, or the degree of slippage. This is because bearing slippage occurs between the rolling elements and the bearing races, not between the cage and the bearing races. Monitoring the cage's rotational speed only indirectly measures the slippage rate, while monitoring the rotational speed of the rolling elements provides a more precise reflection of whether the bearing is slipping and the degree of slippage. Summary of the Invention
[0007] This application discloses a monitoring device, monitoring system and monitoring method for the motion state of rolling bearings, in order to solve the problems of existing detection systems having limited installation, insufficient accuracy or inability to accurately reflect the actual rotational speed of the rolling elements.
[0008] To achieve the above objectives, this application provides the following technical solution:
[0009] In a first aspect, this application provides a monitoring device for the motion state of a rolling bearing. The rolling bearing includes a fixed ring, a rotating ring, and a plurality of rolling elements disposed between the fixed ring and the rotating ring. The monitoring device includes at least one triboelectric sensor, which includes a dielectric film and a stator circuit board. Along the axial direction of the rolling elements, the dielectric film is disposed on the end face of one end of at least one rolling element, and the stator circuit board is disposed on the surface of the fixed ring facing the dielectric film. The stator circuit board is provided with an electrode pair. When the rolling elements rotate, the dielectric film and the electrode pair generate electrostatic induction to generate an electrical signal for monitoring the motion state of the rolling bearing.
[0010] In this process, when the rolling bearing is in operation, the rolling elements roll on the raceway between the fixed and rotating rings, generating rolling friction. During each rotation of the rotating ring, the electrode pairs on the dielectric film and stator circuit board generate at least one electrostatic induction, producing an electrical signal. Because the dielectric film is located on the end face of the rolling element, this electrical signal can be processed to directly obtain the rotational speed of the rolling element. Based on this rotational speed, the slippage rate of the rolling bearing can be determined. Compared to existing methods that use cage rotational speed to determine the slippage rate, the monitoring device in this application can more accurately reflect whether the rolling element is slipping and the degree of slippage. Furthermore, the monitoring device is compact, allowing the triboelectric sensor to be embedded inside the rolling bearing without increasing the bearing size, enabling real-time monitoring of the rolling element rotational speed and its slippage state.
[0011] Furthermore, the dielectric film is prepared from at least one of perfluoroethylene propylene, polytetrafluoroethylene, and polyvinyl chloride.
[0012] Furthermore, the rolling bearing also includes a ring-shaped cage with multiple mounting slots along its circumference for mounting the rolling elements; the dielectric film has a perforated area that at least partially overlaps with the projection of the cage along the axial direction of the rolling elements.
[0013] Furthermore, the multiple rolling elements include a first type of rolling element and a second type of rolling element, and the monitoring device includes a first sensor and a second sensor; wherein, the first sensor includes a first dielectric film disposed on the axial end face of the first type of rolling element, so that the first sensor monitors the motion state of the first type of rolling element; the second sensor includes a second dielectric film disposed on the axial end face of the second type of rolling element, so that the second sensor monitors the motion state of the second type of rolling element.
[0014] Furthermore, along the circumferential direction of the rolling bearing, a second type of rolling element is provided between any two adjacent first type rolling elements.
[0015] Furthermore, the first dielectric film has a first notch at its edge, and the second dielectric film has a second notch at its edge.
[0016] Furthermore, the stator circuit board is an annular plate along the axial direction of the rolling bearing. The annular plate includes a first surface and a second surface disposed opposite to each other. The first surface is provided with an electrode pair, which includes a first electrode and a second electrode. The second surface is provided with a first pad and a second pad for connecting wires. The first electrode and the first pad are electrically connected, and the second electrode and the second pad are electrically connected.
[0017] Furthermore, along the axial direction of the rolling bearing, the end of the fixed ring is provided with an annular retaining edge, and the surface of the annular retaining edge facing the dielectric film is provided with a slot, and the stator circuit board is mounted in the slot; and / or, along the circumferential direction of the annular plate, adjacent first electrodes and second electrodes are spaced apart.
[0018] Secondly, this application provides a monitoring system for the motion state of a rolling bearing. The monitoring system includes a monitoring device as described in the first aspect, as well as a signal acquisition device and a signal processing device. The signal acquisition device is connected to a triboelectric sensor for acquiring electrical signals. The signal processing device is connected to the signal acquisition device to acquire the acquired electrical signals and determine the frequency of the electrical signals. The slippage rate of the rolling bearing is determined based on the frequency.
[0019] Thirdly, this application provides a method for monitoring the motion state of a rolling bearing, the method comprising the following steps:
[0020] Acquire the electrical signal generated by the monitoring device in the first aspect;
[0021] Perform a fast Fourier transform on the electrical signal to obtain the frequency of the electrical signal, and determine the rotational speed of the rolling element based on the frequency;
[0022] The slip rate of a rolling bearing is determined based on its rotational speed. Attached Figure Description
[0023] Figure 1 is a schematic diagram of a monitoring device installed on a rolling bearing according to an embodiment of this application;
[0024] Figure 2 is an exploded view of a rolling bearing equipped with a monitoring device according to an embodiment of this application;
[0025] Figure 3 is a schematic diagram of the structure of a monitoring device according to an embodiment of this application;
[0026] Figure 4 is a schematic diagram of the structure of the rolling element mounted on the cage according to an embodiment of this application;
[0027] Figure 5 is a schematic diagram of the structure of a rolling element mounted on a cage according to an embodiment of this application;
[0028] Figure 6 is a schematic diagram of the structure of a stator circuit board according to an embodiment of this application;
[0029] Figure 7 is a schematic diagram of the structure of a stator circuit board according to an embodiment of this application;
[0030] Figure 8 is a cross-sectional view of a monitoring device installed on a rolling bearing according to an embodiment of this application;
[0031] Figure 9 is a magnified view of a portion of point A shown in Figure 8;
[0032] Figure 10 is a schematic diagram of a monitoring system according to an embodiment of this application;
[0033] Figure 11 is a flowchart of the monitoring method according to an embodiment of this application.
[0034] Reference numerals: 100-Rolling bearing; 110-Fixing ring; 111-Annular flange; 120-Rotating ring; 130-Rolling element; 131-End face; 140-Cage; 200-Triboelectric sensor; 210-Dielectric film; 220-Stator circuit board; 221-First surface; 222-Second surface; 223-First electrode; 224-Second electrode; 225-First pad; 226-Second pad; 230-Wire; 300-Signal acquisition device; 400-Signal processing device;
[0035] 01-Mounting slot. Detailed Implementation
[0036] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0037] The application scenarios described in this application are for the purpose of more clearly illustrating the technical solutions of this application, and do not constitute a limitation on the technical solutions provided in this application. Those skilled in the art will understand that with the emergence of new application scenarios, the technical solutions provided in this application are also applicable to similar technical problems. In the description of this application, unless otherwise stated, "multiple" means two or more.
[0038] Figure 1 is a structural schematic diagram of a monitoring device installed on a rolling bearing according to an embodiment of this application. Figure 2 is an exploded view of a rolling bearing equipped with a monitoring device according to an embodiment of this application. Figure 3 is a structural schematic diagram of a monitoring device according to an embodiment of this application. Please refer to Figures 1 to 3 together. This application provides a monitoring device for the motion state of a rolling bearing 100. The rolling bearing 100 includes a fixed ring 110, a rotating ring 120, and a plurality of rolling elements 130 disposed between the fixed ring 110 and the rotating ring 120. The rotating ring 120 can be an inner ring or an outer ring. If the inner ring is a rotating ring 120, the outer ring can be called the fixed ring 110, and vice versa. For example, when a rotating shaft is fitted in the inner ring, the rotation of the rotating shaft will drive the inner ring to rotate. In this case, the inner ring is the rotating ring 120, and the outer ring is the fixed ring 110. Conversely, when a fixed shaft is fitted in the inner ring and a rotating component is fitted on the ring, the rotation of the rotating component will drive the outer ring to rotate. In this case, the outer ring is a rotating ring 120, and the inner ring is a fixed ring 110.
[0039] Unless otherwise specified, in the rolling bearings 100 of the various embodiments of this application, the fixed ring 110 refers to the outer ring, and the rotating ring 120 refers to the inner ring.
[0040] The monitoring device in this application is applicable to rolling bearings 100 of various types, such as cylindrical roller bearings, deep groove ball bearings, and tapered roller bearings.
[0041] The monitoring device in this embodiment includes at least one triboelectric sensor 200. The triboelectric sensor 200 includes a dielectric film 210 and a stator circuit board 220. Along the axial direction of the rolling element 130, the dielectric film 210 is disposed on the end face 131 of one end of at least one rolling element 130. The stator circuit board 220 is disposed on the surface of the retaining ring 110 facing the dielectric film 210, and electrode pairs are provided on the stator circuit board 220. When the rolling bearing 100 rotates, the rolling element 130 rotates circumferentially, generating relative motion between the dielectric film 210 and the electrode pairs. Due to the principle of triboelectric charging or electrostatic induction, transferred charges are generated between the dielectric film 210 and the electrode pairs, thereby generating a corresponding alternating current signal in the external circuit. This alternating current signal can be used to monitor the motion state of the rolling bearing 100.
[0042] Along the axial direction of the rolling element 130, this application does not limit which end of the rolling element 130 the dielectric film 210 is located, as long as the dielectric film 210 and the stator circuit board 220 are located on the same side of the rolling bearing 100.
[0043] In some embodiments of this application, the dielectric film 210 can be adhered to the end face 131 of the rolling element 130 by adhesive bonding to ensure that it can rotate synchronously with the rolling element 130. In order to improve the reliability of the adhesion between the dielectric film 210 and the rolling element 130, different surface treatments can be applied to the end face 131 of the rolling element 130.
[0044] It is understood that among the multiple rolling elements 130 of the rolling bearing 100, only one rolling element 130 may have a dielectric film 210 on its end face 131, or both two or more rolling elements 130 may have a dielectric film 210 on their end faces 131.
[0045] In some embodiments of this application, the dielectric film 210 may be a thin film of a polymer material with triboelectric effect. Specifically, the material for preparing the dielectric film 210 may be selected from at least one of perfluoroethylene propylene, polytetrafluoroethylene, and polyvinyl chloride.
[0046] The shape of the dielectric film 210 is not limited in this application, as long as the dielectric film 210 and the electrode pair can generate electrostatic induction when the rolling body 130 rotates. For example, the shape of the dielectric film 210 can be circular, annular, square, triangular or other shapes.
[0047] The electrodes of the electrode pair can be metal electrodes such as copper electrodes or aluminum electrodes. The back side of the stator circuit board 220 can be insulated to ensure that the electrical signal is not affected during transmission, thereby improving its anti-interference capability.
[0048] It is understandable that the greater the difference in triboelectric properties between the electrodes and the dielectric layer of the electrode pair, the better the output performance of the triboelectric sensor 200.
[0049] Figure 4 is a schematic diagram of the rolling elements mounted on the cage according to an embodiment of this application, and Figure 5 is a schematic diagram of the rolling elements mounted on the cage according to an embodiment of this application. Please refer to Figures 1 to 5 together. The rolling bearing 100 also includes a ring-shaped cage 140. Along the circumference of the cage 140, the cage 140 is provided with a plurality of mounting grooves 01 for mounting the rolling elements 130. The cage 140 can ensure that the plurality of rolling elements 130 are evenly distributed along the circumference of the rolling bearing 100, while ensuring that adjacent rolling elements 130 do not contact each other. When the rolling bearing 100 is normally installed, the rolling elements 130 are located in the mounting grooves 01 of the cage 140, and there is a circumferential gap between any two adjacent rolling elements 130.
[0050] The cage 140 can be made of copper alloy, non-metallic composite material, etc. The cage 140 can be a cage-type cage 140, or a crown-type or wave-type cage 140.
[0051] In some embodiments of this application, the dielectric film 210 has a hollowed-out area, which at least partially overlaps with the projection of the retainer 140 along the axial direction of the rolling element 130, thereby reducing friction between the dielectric film 210 and the retainer 140 and extending the service life of the monitoring device. The shape and area of the hollowed-out area can be configured based on the shape and area of the overlapping region between the end face 131 of the rolling element 130 and the projection of the retainer 140 along the axial direction of the rolling element 130; that is, the hollowed-out area and the projection of the retainer 140 along the axial direction of the rolling element 130 can partially overlap or completely overlap.
[0052] Figure 6 is a schematic diagram of the structure of a stator circuit board according to an embodiment of the present application, and Figure 7 is a schematic diagram of the structure of a stator circuit board according to an embodiment of the present application. Referring to Figures 6 and 7, the stator circuit board 220 is an annular plate. Along the axial direction of the rolling bearing 100, the annular plate includes a first surface 221 and a second surface 222 disposed opposite to each other. The first surface 221 is provided with an electrode pair, which includes a first electrode 223 and a second electrode 224.
[0053] In some embodiments of this application, the number of electrode pairs may be the same as the number of dielectric films 210.
[0054] In this design, adjacent first electrodes 223 and second electrodes 224 are spaced apart along the circumference of the annular plate. It is understood that the shape of the first electrodes 223 and second electrodes 224 is not limited in this application and can be flexibly configured according to specific needs.
[0055] For example, as shown in FIG6, the first electrode 223 and the second electrode 224 can both be fan-shaped annular, and a second electrode 224 is provided between any two adjacent first electrodes 223, and there is a gap between adjacent first electrodes 223 and second electrodes 224 along the circumference of the annular plate.
[0056] In some embodiments of this application, the second surface 222 is provided with a first pad 225 and a second pad 226 for connecting wires 230. The first electrode 223 and the first pad 225 are electrically connected, and the second electrode 224 and the second pad 226 are electrically connected, thereby realizing circuit conduction between the first electrode 223 and the second electrode 224.
[0057] Figure 8 is a cross-sectional view of a monitoring device installed on a rolling bearing according to an embodiment of the present application, and Figure 9 is a partial enlarged view of point A shown in Figure 8. Referring to Figures 8 and 9, along the axial direction of the rolling bearing 100, the end of the fixing ring 110 is provided with an annular retaining edge 111, and the stator circuit board 220 can be bonded to the surface of the annular retaining edge 111 facing the dielectric film 210.
[0058] Optionally, the axial gap between the dielectric film 210 and the first electrode 223, and the axial gap between the dielectric film 210 and the second electrode 224 are both 0.1-0.3 mm, which can be set according to actual needs so that the triboelectric sensor 200 generates a triboelectric signal of appropriate magnitude.
[0059] In some embodiments of this application, the surface of the annular flange 111 facing the dielectric film 210 is provided with a slot, and the stator circuit board 220 is installed in the slot to adjust the axial gap between the dielectric film 210 and the first electrode 223, the dielectric film 210 and the second electrode 224. The gap will affect the performance of the triboelectric sensor 200.
[0060] Ideally, the multiple rolling elements 130 in the rolling bearing 100 should rotate at the same speed to evenly distribute the load and mitigate wear. However, in practical applications, factors such as bearing wear, contamination, and uneven load can cause differences in the rotational speed of the rolling elements 130. For example, wear may occur on the inner ring, outer ring, and rolling elements 130, affecting their movement. Alternatively, contaminants such as dust and metal shavings may become trapped between the rolling elements 130, thus affecting their rotation.
[0061] Therefore, the monitoring device in this embodiment may include at least two triboelectric sensors 200, each corresponding to one or more rolling elements 130, thereby enabling the monitoring of the rotational speed of different rolling elements 130. The number and position of the rolling elements 130 corresponding to each triboelectric sensor 200 can be set according to actual needs.
[0062] For example, the rolling elements 130 of the rolling bearing 100 can be divided into two groups of rolling elements 130. The monitoring device may include two triboelectric sensors 200, each corresponding to a group of rolling elements 130. The monitoring device with the above structure will be described in detail below.
[0063] The rolling bearing 100 comprises multiple rolling elements 130, including a first type of rolling element and a second type of rolling element. The monitoring device includes a first sensor and a second sensor. The first sensor includes a first dielectric film disposed on the axial end face 131 of the first type of rolling element, enabling the first sensor to monitor the motion state of the first type of rolling element. The second sensor includes a second dielectric film disposed on the axial end face 131 of the second type of rolling element, enabling the second sensor to monitor the motion state of the second type of rolling element. It is understood that by analyzing and comparing the electrical signals generated by the first and second sensors, it can be determined whether the rotational speeds of the first and second rolling elements are the same.
[0064] The first type of rolling element may include one, two, or more rolling elements 130, depending on the actual needs. Similarly, the second type of rolling element may include one, two, or more rolling elements 130, depending on the actual needs.
[0065] In some embodiments of this application, a second type of rolling element is provided between any two adjacent first type rolling elements along the circumferential direction of the rolling bearing 100.
[0066] In some embodiments of this application, the first dielectric film has a first notch at its edge, and the second dielectric film has a second notch at its edge. When the first dielectric film has a notch at its edge, when the first type of rolling element rotates, the overlapping areas of the projections of the first dielectric film and the first electrode 223 along the axial direction of the rolling element 130, and the overlapping areas of the projections of the first dielectric film and the second electrode 224 along the axial direction of the rolling element 130, will change. This will cause the electrical signal to exhibit a discrepancy between the first and second half of a cycle within one cycle. Similarly, when the second dielectric film has a notch at its edge, when the second type of rolling element rotates, the overlapping areas of the projections of the second dielectric film and the first electrode 223 along the axial direction of the rolling element 130, and the overlapping areas of the projections of the second dielectric film and the second electrode 224 along the axial direction of the rolling element 130, will change. This will also cause the electrical signal to exhibit a discrepancy between the first and second half of a cycle within one cycle.
[0067] Therefore, when the rotational speeds of the first and second type of rolling elements differ, the relative positions of the first and second notches along the circumferential direction of the rolling elements change, resulting in a change in the electrical signal. Thus, by monitoring the electrical signals of the two triboelectric sensors, the rotational speed difference between the first and second type of rolling elements can be detected.
[0068] It is understood that the shapes of the first and second notches are not limited in this application. For example, both the first and second notches can be sector-shaped. The areas of the first and second notches can be the same or different. For example, the first notch can be a sector with a central angle of 60 degrees or a sector with a central angle of 120 degrees.
[0069] In some embodiments of this application, the installation process of the monitoring device includes the following steps:
[0070] The dielectric film 210 is attached to the end face 131 of the rolling body 130 respectively, ensuring cleanliness and flatness;
[0071] The surface of the retaining ring 110 facing the dielectric film 210 is cleaned, and the back of the stator circuit board 220 is insulated. The backs of the first electrode 223 and the second electrode 224 are attached to the surface of the retaining ring, and a wire 230 is led out from the first pad 225 and the second pad 226 respectively to realize the connection of the external circuit.
[0072] The structure and installation process of the monitoring device have been explained in detail above. The working process and principle of the monitoring device will be introduced below.
[0073] In the initial state, the dielectric film 210 and the first electrode 223 overlap along the axial direction of the rolling body 130. Due to the difference in electronegativity between the dielectric film 210 and the first electrode 223, negative charges accumulate on the surface of the dielectric film 210. According to the law of conservation of charge, an equal amount of positive charges accumulate on the surface of the first electrode 223. At this time, the positive and negative charges cancel each other out, and the electrostatic equilibrium is reached. Since the dielectric film 210 and the first electrode 223 are in a non-contact mode, the amount of charge transferred between the dielectric film 210 and the first electrode 223 is relatively small.
[0074] As the dielectric film 210 rotates under the drive of the cage 140, it begins to rotate relative to the first electrode 223. The dielectric film 210 gradually overlaps with the projection of the second electrode 224 along the axial direction of the rolling element 130, creating a potential difference between the two electrodes. This causes positive charges to flow from the first electrode 223 to the second electrode 224 along the direction of rotation. When the rotor and the projection of the second electrode 224 along the axial direction of the rolling element 130 completely overlap, all positive charges are transferred to the second electrode 224, returning to electrostatic equilibrium.
[0075] As the cage 140 continues to rotate, the positive charge on the second electrode 224 flows in the opposite direction again, towards the first electrode 223, forming a reverse current in the external circuit. Due to the electrostatic induction between the dielectric film 210 and the electrode pair, the charge on the dielectric film 210 gradually begins to accumulate. The above-mentioned charge transfer process is repeated periodically, and the charge on the dielectric film 210 continues to increase until saturation, thereby achieving stable output.
[0076] Based on the same technical concept, this application also provides a monitoring system for the motion state of a rolling bearing. Figure 10 is a schematic diagram of a monitoring system according to an embodiment of this application. Referring to Figure 10, the monitoring system includes a signal acquisition device 300, a signal processing device 400, and monitoring devices in various possible embodiments of this application. The signal acquisition device 300 is signal-connected to the triboelectric sensor 200 to acquire electrical signals. The signal processing device 400 is signal-connected to the signal acquisition device 300 to acquire the acquired electrical signals and determine the frequency of the electrical signals. The slippage rate of the rolling bearing 100 is determined based on the frequency.
[0077] The signal acquisition device 300 can be a data acquisition card, which is used to collect data from the triboelectric sensor 200, convert it into a form that can be processed by a computer, and then transmit it to the signal processing device 400 for processing.
[0078] In some embodiments of this application, the signal acquisition device 300 can be wirelessly connected to the triboelectric sensor 200 via infrared or other means.
[0079] The signal processing device 400 includes a digital signal processor, which can be used to perform complex mathematical operations, such as Fast Fourier Transform (FFT) and signal compression.
[0080] In some embodiments of this application, the monitoring system may include a display device, which includes a display screen that can be used to display the real-time rotational speed and slippage rate of the rolling element 130.
[0081] In addition, based on actual working conditions, the operator can set a threshold for the slippage rate of the rolling bearing 100 and input it into the display device. When the slippage rate of the rolling bearing 100 exceeds the threshold, an alarm can be triggered on the display.
[0082] The working process of the monitoring system in this embodiment is as follows:
[0083] The signal acquisition device 300 acquires the time-domain signal from the triboelectric speed sensor and transmits it to the signal processing device 400. The signal processing device 400 extracts the frequency of the signal by performing FFT. The frequency can reflect the rotational speed of the rolling element 130. The slip rate of the rolling element 130 can be monitored in real time by calculation using the formula.
[0084] Based on the same technical concept, this application also provides a method for monitoring the motion state of a rolling bearing 100. Figure 11 is a flowchart of the monitoring method of a monitoring system according to an embodiment of this application. Referring to Figure 11, the monitoring method includes the following steps:
[0085] Acquire electrical signals generated by the monitoring device in various possible embodiments of this application;
[0086] Perform a fast Fourier transform on the electrical signal to obtain the frequency of the electrical signal, and determine the rotational speed of the rolling element 130 based on the frequency;
[0087] The slip rate of the rolling bearing 100 is determined based on the rotational speed, and the motion state of the rolling bearing 100 can be evaluated accordingly.
[0088] In summary, the monitoring device, monitoring system, and monitoring method in the embodiments of this application have the following characteristics: Beneficial effects:
[0089] 1) It can be used for in-situ monitoring of the rotational speed and slippage state of the rolling elements 130 of the rolling bearing 100, and can analyze the slippage state of a single rolling element 130 at a more microscopic level.
[0090] 2) The triboelectric sensor 200 has a compact structure, which improves the integration of the monitoring device. The triboelectric sensor 200 can be embedded inside the bearing without increasing the bearing size, which has less impact on the dynamic characteristics of the bearing, high reliability, and wide applicability.
[0091] 3) The monitoring system can realize real-time monitoring and slippage warning of the bearing rolling elements at 130 rpm through signal processing and threshold setting.
[0092] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A device for monitoring the motion state of a rolling bearing, the rolling bearing comprising a fixed ring, a rotating ring, and a plurality of rolling elements disposed between the fixed ring and the rotating ring, characterized in that, The monitoring device includes at least one triboelectric sensor, which includes a dielectric film and a stator circuit board. Along the axial direction of the rolling element, the dielectric film is disposed on the end face of at least one end of the rolling element, and the stator circuit board is disposed on the surface of the retaining ring facing the dielectric film. The stator circuit board is provided with electrode pairs. When the rolling element rotates, the dielectric film and the electrode pair generate electrostatic induction to generate an electrical signal for monitoring the motion state of the rolling bearing.
2. The monitoring device according to claim 1, characterized in that, The dielectric film is prepared from at least one of perfluoroethylene propylene, polytetrafluoroethylene, and polyvinyl chloride.
3. The monitoring device according to claim 1, characterized in that, The rolling bearing further includes a ring-shaped cage, and along the circumference of the cage, the cage is provided with a plurality of mounting slots for mounting the rolling elements; The dielectric film has a cutout area that at least partially overlaps with the projection of the cage along the axial direction of the rolling element.
4. The monitoring device according to any one of claims 1-3, characterized in that, The plurality of rolling elements includes a first type of rolling element and a second type of rolling element, and the monitoring device includes a first sensor and a second sensor; The first sensor includes a first dielectric film, which is disposed on the axial end face of the first type of rolling body, so that the first sensor can monitor the motion state of the first type of rolling body. The second sensor includes a second dielectric film disposed on the axial end face of the second type of rolling element, so that the second sensor can monitor the motion state of the second type of rolling element.
5. The monitoring device according to claim 4, characterized in that, Along the circumferential direction of the rolling bearing, a second type of rolling element is provided between any two adjacent first type rolling elements.
6. The monitoring device according to claim 4, characterized in that, The first dielectric film has a first notch at its edge, and the second dielectric film has a second notch at its edge.
7. The monitoring device according to any one of claims 1-3, characterized in that, The stator circuit board is an annular plate along the axial direction of the rolling bearing. The annular plate includes a first surface and a second surface disposed opposite to each other. The first surface is provided with the electrode pair, which includes a first electrode and a second electrode. The second surface is provided with a first pad and a second pad for connecting wires. The first electrode and the first pad are electrically connected, and the second electrode and the second pad are electrically connected.
8. The monitoring device according to claim 7, characterized in that, Along the axial direction of the rolling bearing, the end of the fixed collar is provided with an annular retaining edge, and the surface of the annular retaining edge facing the dielectric film is provided with a groove, and the stator circuit board is mounted in the groove; And / or, along the circumference of the annular plate, adjacent first electrodes and second electrodes are spaced apart.
9. A system for monitoring the motion state of a rolling bearing, characterized in that, include: The monitoring device as described in any one of claims 1-8; A signal acquisition device is connected to the triboelectric sensor for acquiring the electrical signal. A signal processing device is connected to the signal acquisition device to acquire the electrical signal acquired by the device and determine the frequency of the electrical signal. The slip rate of the rolling bearing is determined based on the frequency.
10. A method for monitoring the motion state of a rolling bearing, characterized in that, Includes the following steps: Acquire the electrical signal generated by the monitoring device as described in any one of claims 1-8; The frequency of the electrical signal is obtained by performing a fast Fourier transform on the electrical signal, and the rotational speed of the rolling element is determined based on the frequency. The slip rate of the rolling bearing is determined based on the rotational speed.