A ring array electrostatic sensor for bearing condition monitoring

Abstract

The invention belongs to the field of bearing state monitoring, and discloses a circular ring array type electrostatic sensor for bearing state monitoring, comprising a circular array electrode plate, a circular shell and an end cover; the circular array electrode plate is connected to the bottom of the circular shell, a plurality of electrodes are arranged circumferentially on the circular array electrode plate, and a plurality of circuit boards are arranged circumferentially on the circular shell; a charge-voltage conversion circuit, a probe pin, a power line and a signal transmission line are arranged on the circuit board, the probe pin, the power line and the signal transmission line are all connected to the charge-voltage conversion circuit, and a plurality of probe pins are connected to a plurality of electrodes in a one-to-one correspondence; the end cover is connected to the top of the circular shell, a wire hole is provided on the end cover, one end of the power line and the signal transmission line are both passed through the wire hole and are located outside the circular shell; wherein the charge-voltage conversion circuit is used for receiving an induced charge signal of the electrode through the probe pin, and converting it into a voltage signal for transmission by the signal transmission line, thereby effectively solving the problem of insufficient information acquisition by a single electrode.

Description

Technical Field

[0001] The invention belongs to the field of bearing state monitoring and relates to a circular ring array type electrostatic sensor for bearing state monitoring. Background Art

[0002] Rolling bearings are key components for power transmission in rotating equipment. They are used to support rotating bodies such as shafts, gears, drill bits, and pulleys, and reduce friction during the rotation process to improve transmission efficiency. Since bearings work continuously for a long time under high loads, high speeds, or harsh environments, and are often accompanied by harsh environments such as high temperatures and dust, the performance of bearings gradually declines over the years, making the bearings susceptible to damage and failure. Statistics show that bearing failures account for about 30% of rotating mechanical equipment failures, especially in small rotating equipment, where the proportion of failures is as high as 40% to 90%.

[0003] The acquisition of monitoring signals is the basis of rolling bearing fault diagnosis and status assessment. Common bearing status measurement signals include vibration signals, acoustic emission signals, and oil analysis. The acquisition of fault signals has become a bottleneck restricting the development of fault diagnosis technology. It is urgent to find new monitoring methods to make up for the shortcomings of current conventional monitoring technology from the physical field. Electrostatic monitoring technology directly senses the charge transfer phenomenon generated by the friction pair of rolling bearings during friction, collision, and impact, avoiding the influence of attenuation and superposition interference during the propagation of fault phenomena, and thus has better anti-interference ability. However, current electrostatic sensors are usually single electrostatic electrodes, which have the problem of insufficient sensitive area for single electrostatic electrodes to obtain, which makes it impossible to achieve global real-time monitoring of the wear process in the annular working cavity of the bearing. Summary of the invention

[0004] The purpose of the present invention is to overcome the problem in the above-mentioned prior art that the existing electrostatic sensor has an insufficient sensitive area obtained by a single electrostatic electrode, which leads to the inability to realize global real-time monitoring of the wear process in the annular working cavity of the bearing, and to provide a circular array electrostatic sensor for bearing status monitoring.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A circular array electrostatic sensor for bearing condition monitoring, comprising a circular array electrode plate, a circular housing and an end cover;

[0007] The annular array electrode plate is connected to the bottom of the annular shell, a plurality of electrodes are arranged in an annular direction on the annular array electrode plate, and a plurality of circuit boards are arranged in an annular direction on the annular shell; a charge-voltage conversion circuit, a probe pin, a power line and a signal transmission line are arranged on the circuit board, the probe pin, the power line and the signal transmission line are all connected to the charge-voltage conversion circuit, and a plurality of probe pins are connected to a plurality of electrodes in a one-to-one correspondence; the end cover is connected to the top of the annular shell, a wire hole is provided on the end cover, and one end of the power line and the signal transmission line are both passed through the wire hole and are located outside the annular shell;

[0008] The charge-to-voltage conversion circuit is used to receive the induced charge signal of the electrode through the probe pin and convert it into a voltage signal for transmission through the signal transmission line.

[0009] Optionally, it also includes an internal thread ring, which is sleeved on the end cover and the outside of the annular shell, and the end cover is connected to the top of the annular shell through the internal thread ring.

[0010] Optionally, a plurality of via pads are provided on the annular array electrode plate, and a plurality of probe pins are connected to a plurality of electrodes in a one-to-one correspondence through the plurality of via pads.

[0011] Optionally, a signal repeater is also included. One end of the signal transmission line passing through the wire hole is connected to the signal repeater. The signal repeater filters and amplifies the voltage signal and then transmits it to the monitoring system.

[0012] Optionally, the signal repeater includes a power stabilizing unit, a filtering circuit and a voltage amplifying circuit; the power stabilizing unit is connected to the power line, and the signal transmission line is connected to the voltage amplifying circuit through the filtering circuit; the length of the signal transmission line connected to the filtering circuit is between 10 and 20 cm.

[0013] Optionally, the annular array electrode plate is made of a printed circuit board, and 12 to 16 rectangular electrodes are arranged at equal angles in a circular direction on the annular array electrode plate. The central axis of the electrode in the length direction is placed along the radial direction of the annular array electrode plate. The width of the electrode is 2 to 4 mm, and the upper and lower boundaries of the electrode length are at least 4 mm away from the edge of the annular array electrode plate.

[0014] Optionally, a power line welding pad and a signal transmission line welding pad are further provided on the circuit board; the power line is connected to the circuit board via the power line welding pad, and the signal transmission line is connected to the circuit board via the signal transmission line welding pad; the power lines of two adjacent circuit boards are connected to each other;

[0015] The N circuit boards arranged in a ring direction are defined to be a first circuit board to an Nth circuit board; wherein:

[0016] 2i-1 signal transmission line welding pads are arranged on the i-th circuit board; the first signal transmission line welding pad of the first circuit board is connected to the first signal transmission line welding pad of the second circuit board through a signal transmission line; the 1st to i-1st signal transmission line welding pads of the i-th circuit board are connected to the i-1st to 2i-3rd signal transmission line welding pads of the i-th circuit board respectively through signal transmission lines; the i-th to 2i-1st signal transmission line welding pads of the i-th circuit board are connected to the 1st to i signal transmission line welding pads of the i+1th circuit board respectively through signal transmission lines; wherein, 1<i<N; one end of the signal transmission line connected to the N-th to 2N-1 signal transmission line welding pads of the N-th circuit board passes through the wire hole and is located outside the annular shell.

[0017] Optionally, a power line welding pad and 2N signal transmission line welding pads are also provided on the circuit board; the power line is connected to the circuit board via the power line welding pad, and the signal transmission line is connected to the circuit board via the signal transmission line welding pad; the power lines of two adjacent circuit boards are connected to each other;

[0018] The N circuit boards arranged in a ring direction are defined to be a first circuit board to an Nth circuit board; wherein:

[0019] The Nth signal transmission line welding pad of the first circuit board is connected to the first signal transmission line welding pad of the second circuit board through a signal transmission line, and the Nth to N+i-1th signal transmission line welding pads of the i-th circuit board are connected to the 1st to i-1st signal transmission line welding pads of the i+1th circuit board through signal transmission lines, respectively, wherein 1<i<N; the signal transmission lines connected to the Nth to 2N-1 signal transmission line welding pads of the Nth circuit board all pass through the wire holes and are located outside the annular shell.

[0020] Optionally, the inner diameter of the annular shell is 2 to 4 mm larger than the inner diameter of the bearing to be monitored, the outer diameter is the same as the outer diameter of the bearing to be monitored, the height is 15 to 25 mm, the material is bearing steel, and several fixing grooves are opened on the annular shell, and the circuit board is arranged inside the fixing grooves.

[0021] Optionally, the annular array electrode plate is fixedly connected to the bottom of the annular housing by screws.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The circular ring array electrostatic sensor for bearing status monitoring of the present invention adopts a multi-electrode structure with an annular distribution, divides the wear area of ​​the bearing into several sensitive areas for collecting induced charge signals, and realizes the monitoring of the friction charges generated between the rollers, inner rings, outer rings and retaining frames during the operation of the bearing, which can effectively make up for the problem of insufficient information obtained by a single electrode. At the same time, the location information of the multi-electrode 8 associated fault is more conducive to fault analysis. The circular ring array electrostatic sensor is connected to the on-site monitoring system, and the output signal can be observed on the system to judge the status of the bearing. A new device for bearing status monitoring is provided, which improves the accuracy of bearing status judgment and effectively avoids losses due to misjudgment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 An exploded view of a circular array electrostatic sensor according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the signal transmission principle of the circular array electrostatic sensor according to an embodiment of the present invention;

[0026] Figure 3 A schematic diagram of the structure of a ring array electrode plate according to an embodiment of the present invention;

[0027] Figure 4 A schematic diagram of the circuit board structure of an embodiment of the present invention;

[0028] Figure 5 A schematic diagram of the annular housing structure of an embodiment of the present invention;

[0029] Figure 6 A bottom view of an annular housing according to an embodiment of the present invention;

[0030] Figure 7 This is a schematic diagram of the end cover structure of an embodiment of the present invention;

[0031] Figure 8 This is a schematic diagram of the structure of an internal thread ring according to an embodiment of the present invention;

[0032] Fig. 9 This is a schematic diagram of power line connection according to an embodiment of the present invention;

[0033] Fig.10 This is a wiring diagram of a signal transmission line according to an embodiment of the present invention;

[0034] Fig.11 The figure is a schematic diagram of the structure of an annular housing for mounting a circuit board according to an embodiment of the present invention.

[0035] Among them: 1-annular array electrode plate; 2-annular outer shell; 3-end cover; 4-inner thread ring; 5-circuit board; 6-threaded hole; 7-through hole pad; 8-electrode; 9-power line welding pad; 10-signal transmission line welding pad; 11-probe pin; 12-charge-voltage conversion circuit; 13-power line; 14-signal transmission line; 15-fixing groove; 16-through hole. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0037] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0039] See also Figures 1 to 6 In one embodiment of the present invention, a circular array electrostatic sensor for bearing condition monitoring is provided, which can be used for triboelectric charging monitoring of the global wear area of ​​a rolling bearing.

[0040] Specifically, the annular array electrostatic sensor for bearing status monitoring includes an annular array electrode plate 1, an annular shell 2 and an end cover 3; the annular array electrode plate 1 is connected to the bottom of the annular shell 2, a plurality of electrodes 8 are arranged in an annular direction on the annular array electrode plate 1, and a plurality of circuit boards 5 are arranged in an annular direction on the annular shell 2; a charge-voltage conversion circuit 12, a probe pin 11, a power line 13 and a signal transmission line 14 are arranged on the circuit board 5, the probe pin 11, the power line 13 and the signal transmission line 14 are all connected to the charge-voltage conversion circuit 12, and a plurality of probe pins 11 are connected to a plurality of electrodes 8 in a one-to-one correspondence; the end cover 3 is connected to the top of the annular shell 2, a wire hole 16 is provided on the end cover 3, one end of the power line 13 and the signal transmission line 14 are both passed through the wire hole 16 and are located outside the annular shell 2; wherein the charge-voltage conversion circuit 12 is used to receive the induced charge signal of the electrode 8 through the probe pin 11, and convert it into a voltage signal for transmission by the signal transmission line 14.

[0041] When in use, the circular array electrostatic sensor for bearing status monitoring of the present invention can be installed on the side of the bearing to be monitored, and the axial center of the circular array electrostatic sensor coincides with the central axis of the bearing to be monitored, ensuring that all electrodes 8 arranged in an annular direction on the annular array electrode plate 1 can effectively monitor the raceway wear area, and sense the charge phenomenon generated by the global wear during the operation of the bearing, and send the obtained induced charge signal to the charge voltage conversion circuit 12 through the probe pin 11 for conversion, and obtain a voltage signal and transmit it by the signal transmission line 14 for subsequent analysis and processing.

[0042] In summary, the circular array electrostatic sensor for bearing status monitoring of the present invention adopts a multi-electrode 8 structure with a ring distribution, divides the wear area of ​​the bearing into several sensitive areas for induced charge signal collection, and realizes the monitoring of the friction charge generated between the roller, inner ring, outer ring and retaining frame during the operation of the bearing, which can effectively make up for the problem of insufficient information obtained by a single electrode 8. At the same time, the location information of the multi-electrode 8 associated fault is more conducive to fault analysis. The circular array electrostatic sensor is connected to the on-site monitoring system, and the output signal can be observed on the system to judge the status of the bearing. A new device for bearing status monitoring is provided, which improves the accuracy of bearing status judgment and effectively avoids losses due to misjudgment.

[0043] See also Figure 7In a possible implementation, the annular array electrostatic sensor for bearing condition monitoring further includes an internal thread ring 4, which is sleeved on the end cover 3 and the outside of the annular shell 2, and the end cover 3 is connected to the top of the annular shell 2 through the internal thread ring 4. Specifically, the end cover 3 is annular in shape, with the same outer diameter as the annular shell 2, and the end cover 3 and the annular shell 2 are both provided with external threads. The internal thread ring 4 is annular in shape, with the same outer diameter as the annular shell 2, and has an internal thread inside for fixing the annular shell 2 and the end cover 3.

[0044] In a possible implementation, a plurality of via pads 7 are provided on the annular array electrode plate 1, and a plurality of probe pins 11 are connected to a plurality of electrodes 8 in a one-to-one correspondence through the plurality of via pads 7. Specifically, all electrodes 8 are electrically connected to a corresponding number of via pads 7 on the annular array electrode plate 1, and the via pads 7 are used to connect the probe pins 11 on the circuit board 5, so as to achieve a stable connection between the electrodes 8 and the probe pins 11.

[0045] See also Figure 8 In a possible implementation, the circular array electrostatic sensor for bearing condition monitoring also includes a signal repeater.

[0046] One end of the signal transmission line 14 passes through the wire hole 16 and is connected to the signal repeater, which filters and amplifies the voltage signal and transmits it to the monitoring system. Optionally, the signal repeater includes a power supply voltage stabilization unit, a filter circuit and a voltage amplification circuit; the power supply voltage stabilization unit is connected to the power supply line 13, and the signal transmission line 14 is connected to the voltage amplification circuit through the filter circuit; the length of the signal transmission line 14 connected to the filter circuit is between 10 and 20 cm, and the output signal and power supply of the signal repeater are connected to the external monitoring system.

[0047] In a possible embodiment, the annular array electrode plate 1 is made of a printed circuit board, and other insulating materials may be used. 12 to 16 rectangular electrodes 8 are arranged at equal angles in a circular direction on the annular array electrode plate 1. The central axis of the length direction of the electrode 8 is placed along the radial direction of the annular array electrode plate 1. The width of the electrode 8 is 2 to 4 mm, and the upper and lower boundaries of the length of the electrode 8 are at least 4 mm away from the edge of the annular array electrode plate 1.

[0048] In a possible embodiment, the inner diameter of the annular shell 2 is 2 to 4 mm larger than the inner diameter of the bearing to be monitored, the outer diameter is the same as the outer diameter of the bearing to be monitored, the height is 15 to 25 mm, and the material is bearing steel. A plurality of fixing grooves 15 are provided on the annular shell 2, and the circuit board 5 is arranged inside the fixing groove 15.

[0049] In a possible implementation, the annular array electrode plate 1 is fixedly connected to the bottom of the annular housing 2 by screws. Specifically, the bottom of the annular housing 2 includes a plurality of threaded holes 6 for mounting the annular array electrode plate 1, and a plurality of mounting holes are provided on the annular array electrode plate 1, and the mounting holes and the threaded holes 6 are fixed by screws.

[0050] In a possible implementation manner, a power line welding pad 9 and a signal transmission line welding pad 10 are further provided on the circuit board 5; the power line 13 is connected to the circuit board 5 via the power line welding pad 9, and the signal transmission line 14 is connected to the circuit board 5 via the signal transmission line welding pad 10; the power lines 13 of two adjacent circuit boards 5 are connected to each other; the N circuit boards 5 arranged in a ring direction are defined as the first circuit board to the Nth circuit board; wherein: 2i-1 signal transmission line welding pads 10 are provided on the i-th circuit board; the first signal transmission line welding pad 10 of the first circuit board is connected to the first signal transmission line welding pad 10 of the second circuit board The disks 10 are connected through signal transmission lines 14; the 1st to i-1st signal transmission line welding pads 10 of the i-th circuit board are connected with the i-1st to 2i-3 signal transmission line welding pads 10 of the i-1th circuit board respectively through the signal transmission lines 14; the i-th to 2i-1st signal transmission line welding pads 10 of the i-th circuit board are connected with the 1st to i signal transmission line welding pads 10 of the i+1th circuit board respectively through the signal transmission lines 14; wherein, 1<i<N; one end of the signal transmission line 14 connected to the N-th to 2N-1 signal transmission line welding pads 10 of the Nth circuit board passes through the wire hole 16 and is located outside the annular shell 2.

[0051] See also Fig. 9 and 10 In a possible implementation manner, a power line welding pad 9 and 2N signal transmission line welding pads 10 are also provided on the circuit board 5; the power line 13 is connected to the circuit board 5 through the power line welding pad 9, and the signal transmission line 14 is connected to the circuit board 5 through the signal transmission line welding pad 10; the power lines 13 of two adjacent circuit boards 5 are connected to each other; the N circuit boards 5 arranged in a ring direction are defined as the first circuit board to the Nth circuit board respectively; wherein: the Nth signal transmission line welding pad 10 of the first circuit board is connected to the first signal transmission line welding pad 10 of the second circuit board through the signal transmission line 14, and the Nth to N+i-1th signal transmission line welding pads 10 of the i-th circuit board are connected to the 1st to i-1st signal transmission line welding pads 10 of the i+1th circuit board through the signal transmission lines 14 respectively, wherein 1<i<N; the signal transmission lines 14 connected to the Nth to 2N-1th signal transmission line welding pads 10 of the Nth circuit board all pass through the wire holes 16 and are located outside the annular housing 2. According to the above-mentioned ring connection mode, the power line 13 can be shared, and the signal transmission line 14 can be aggregated and led out from the last circuit board 5. After the lines are aggregated, they are output together through the wire holes 16, which is convenient for wiring.

[0052] In summary, the circular array electrostatic sensor for bearing status monitoring of the present invention, in view of the rotational symmetry of the bearing, embeds a plurality of electrodes 8 in a circular ring array electrode plate 1 to form an electrostatic electrode 8 array. In order to avoid the influence of the internal charge transfer of the transmission line between the electrode 8 and the charge-to-voltage conversion circuit 12 on the circuit output, a long strip circuit board is designed to dock with the electrode 8, and the electrostatic electrode 8 array and a plurality of long strip circuit boards are installed on a specially designed circular housing 2. The circuit leads are connected to the external signal repeater through the end cover 3. The circular housing 2 and the end cover 3 are both provided with external threads, and the circular housing 2 and the end cover 3 are fixed with an internal thread ring 4, so as to be integrated into a circular array electrostatic sensor. The circular array electrostatic sensor can be installed on the side of the bearing to be tested, and senses the charge phenomenon generated by the global wear during the working process of the bearing, which can effectively make up for the defect that the current probe-type electrostatic monitoring does not obtain enough charge information inside the bearing.

[0053] The assembly and working steps of the circular array electrostatic sensor for bearing condition monitoring of the present invention are as follows:

[0054] a. Insert all the long strip circuit boards 5 into the fixing grooves 15 in the annular housing 2 in sequence, aligning the bottom with the bottom of the annular housing 2. The effect after installation is as follows: Fig.11 shown.

[0055] b. According to Fig. 9 and Fig.10 The connection method shown is to solder the power supply wiring and signal transmission lines 14 of all circuit boards 5 accordingly.

[0056] c. The probe pins 11 at the bottom of the circuit board 5 will extend out of the bottom of the annular housing 2 by a certain distance, and all the probe pins 11 will pass through the via pads 7 on the annular array electrode plate 1 .

[0057] d. Use screws to fix the annular array electrode plate 1 to the bottom of the annular housing 2. After fixation, weld the probe pins 11 to the via pads 7 on the annular array electrode plate 1, and cut off the portion of the probe pins 11 that protrudes beyond the plane of the annular array electrode plate 1.

[0058] e. After passing the power line 13 and the signal transmission line 14 through the wire hole 16 on the end cover 3, use the internal thread ring 4 to tighten and fix the annular shell 2 and the end cover 3.

[0059] f. The extended power line 13 and the signal transmission line 14 are connected to the signal repeater. The signal repeater stabilizes the external power supply voltage to provide voltage for the long circuit board 5, and amplifies and filters the output signal of the long circuit board 5. The amplified and filtered signal is connected to the external monitoring system.

[0060] g. After assembly, install it on the side of the bearing to be tested, and the axial center of the circular array electrostatic sensor coincides with the central axis of the bearing to be tested, ensuring that all electrodes 8 can effectively monitor the raceway wear area of ​​the bearing to be tested.

[0061] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A circular array electrostatic sensor for bearing condition monitoring, characterized in that: It comprises an annular array electrode plate (1), an annular housing (2) and an end cover (3); The annular array electrode plate (1) is connected to the bottom of the annular shell (2); a plurality of electrodes (8) are arranged in an annular direction on the annular array electrode plate (1); and a plurality of circuit boards (5) are arranged in an annular direction on the annular shell (2); a charge-voltage conversion circuit (12), a probe pin (11), a power line (13) and a signal transmission line (14) are arranged on the circuit board (5); the probe pin (11), the power line (13) and the signal transmission line (14) are all connected to the charge-voltage conversion circuit (12); and the plurality of probe pins (11) and the plurality of electrodes (8) are connected in a one-to-one correspondence; the end cover (3) is connected to the top of the annular shell (2); a wire hole (16) is provided on the end cover (3); one end of the power line (13) and the signal transmission line (14) pass through the wire hole (16) and are located outside the annular shell (2); The charge-to-voltage conversion circuit (12) is used to receive the induced charge signal of the electrode (8) through the probe pin (11), and convert it into a voltage signal for transmission via the signal transmission line (14); It also includes an internal thread ring (4), which is sleeved on the end cover (3) and the outside of the annular shell (2), and the end cover (3) is connected to the top of the annular shell (2) through the internal thread ring (4); A plurality of via pads (7) are provided on the annular array electrode plate (1), and a plurality of probe pins (11) are connected to a plurality of electrodes (8) in a one-to-one correspondence through the plurality of via pads (7); The annular array electrode plate (1) is made of a printed circuit board, and 12 to 16 rectangular electrodes (8) are arranged at equal angles in a circular direction on the annular array electrode plate (1). The central axis of the length direction of the electrode (8) is placed along the radial direction of the annular array electrode plate (1). The width of the electrode (8) is 2 to 4 mm, and the upper and lower boundaries of the length of the electrode (8) are at least 4 mm away from the edge of the annular array electrode plate (1).

2. The circular array electrostatic sensor for bearing condition monitoring according to claim 1, characterized in that: It also includes a signal repeater. One end of the signal transmission line (14) passes through the line hole (16) and is connected to the signal repeater. The signal repeater is used to filter and amplify the voltage signal and then transmit it to the monitoring system.

3. The circular ring array electrostatic sensor for bearing condition monitoring according to claim 2, characterized in that: The signal repeater comprises a power supply voltage stabilization unit, a filter circuit and a voltage amplification circuit; the power supply voltage stabilization unit is connected to a power line (13), and a signal transmission line (14) is connected to the voltage amplification circuit via the filter circuit; the length of the signal transmission line (14) connected to the filter circuit is between 10 and 20 cm.

4. The circular ring array electrostatic sensor for bearing condition monitoring according to claim 1, characterized in that: The circuit board (5) is also provided with a power line welding pad (9) and a signal transmission line welding pad (10); the power line (13) is connected to the circuit board (5) via the power line welding pad (9), and the signal transmission line (14) is connected to the circuit board (5) via the signal transmission line welding pad (10); the power lines (13) of two adjacent circuit boards (5) are connected to each other; The N circuit boards (5) arranged in a ring direction are defined as a first circuit board to an Nth circuit board; wherein: 2i-1 signal transmission line welding pads (10) are arranged on the i-th circuit board; the first signal transmission line welding pad (10) of the first circuit board is connected to the first signal transmission line welding pad (10) of the second circuit board via a signal transmission line (14); the 1st to 1i-1st signal transmission line welding pads (10) of the i-th circuit board are connected to the i-1st to 2i-3rd signal transmission line welding pads (10) of the i-(1)th circuit board respectively via a signal transmission line (14); the i-th to 2i-1st signal transmission line welding pads (10) of the i-th circuit board are connected to the 1st to i-th signal transmission line welding pads (10) of the i+1th circuit board respectively via a signal transmission line (14); wherein 1<i<N; one end of the signal transmission line (14) connected to the N-th to 2N-1st signal transmission line welding pads (10) of the N-th circuit board passes through a wire hole (16) and is located outside the annular housing (2).

5. The circular array electrostatic sensor for bearing condition monitoring according to claim 1, characterized in that: The circuit board (5) is also provided with a power line welding pad (9) and 2N signal transmission line welding pads (10); the power line (13) is connected to the circuit board (5) via the power line welding pad (9), and the signal transmission line (14) is connected to the circuit board (5) via the signal transmission line welding pad (10); the power lines (13) of two adjacent circuit boards (5) are connected to each other; The N circuit boards (5) arranged in a ring direction are defined as a first circuit board to an Nth circuit board; wherein: The Nth signal transmission line welding pad (10) of the first circuit board is connected to the first signal transmission line welding pad (10) of the second circuit board via a signal transmission line (14); the Nth to N+i-1th signal transmission line welding pads (10) of the i-th circuit board are connected to the 1st to i-1st signal transmission line welding pads (10) of the i+1th circuit board via signal transmission lines (14), respectively, wherein 1<i<N; the signal transmission lines (14) connected to the Nth to 2N-1th signal transmission line welding pads (10) of the Nth circuit board all pass through the wire holes (16) and are located outside the annular housing (2).

6. The circular ring array electrostatic sensor for bearing condition monitoring according to claim 1, characterized in that: The inner diameter of the annular housing (2) is 2-4 mm larger than the inner diameter of the bearing to be monitored, the outer diameter is the same as the outer diameter of the bearing to be monitored, the height is 15-25 mm, and the material is bearing steel. A plurality of fixing grooves (15) are provided on the annular housing (2), and the circuit board (5) is arranged inside the fixing grooves (15).

7. The circular array electrostatic sensor for bearing condition monitoring according to claim 1, characterized in that: The annular array electrode plate (1) is fixedly connected to the bottom of the annular housing (2) by means of screws.

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