CN218481163U - Passive wireless vibration monitoring sensor - Google Patents

Abstract

The application discloses passive wireless vibration monitoring sensor is hit by the vibration of encapsulation in sensor housing inside and picks up unit, vibration energy collection unit, signal conditioning and transmitting element and constitute, still can convert vibration energy into the electric energy when carrying out vibration monitoring to the part under test, need not the wireless transmission that external power supply just can realize monitoring signal. The sensor has the advantages that multiple shields are adopted in the sensor, so that electromagnetic interference in the operation of the rotating electromechanical equipment is effectively inhibited; the detection element adopts an annular shearing piezoelectric ceramic crystal fixed by a heat-shrinkable ring, so that the problems of temperature drift and working temperature limitation of the existing state monitoring sensor are solved; the electric energy required by the working of the sensor is provided through vibration energy collection, so that the problem that the conventional wireless sensor cannot effectively supply energy is solved; monitoring signals are transmitted in a wireless mode, the installation cost of the sensor is reduced, and the problem that the traditional sensor is difficult to wire on the rotary electromechanical equipment is solved.

Description

Passive wireless vibration monitoring sensor

Technical Field

The application relates to the field of state monitoring sensors, in particular to a passive wireless vibration monitoring sensor for large-scale rotating electromechanical equipment.

Background

For large-scale rotating electromechanical equipment, most faults of the large-scale rotating electromechanical equipment are closely related to mechanical motion or vibration, and vibration monitoring has the characteristics of direct and real-time performance and wide fault type coverage range. At present, vibration monitoring is a core technology in various predictive maintenance aiming at large-scale rotating electromechanical equipment, and other predictive maintenance technologies (such as infrared thermography, oil analysis, electrical diagnosis and the like) are effective supplements of the vibration monitoring technology.

The sensors commonly used for monitoring the vibration state of large-scale rotating electromechanical equipment can be classified into piezoelectric type, piezoresistive type, capacitive type, inductive type and photoelectric type according to the working principle, and the piezoelectric type acceleration sensor becomes the most commonly used vibration measurement sensor due to the advantages of wide frequency range, wide measuring range, small volume, light weight and the like. The piezoelectric acceleration sensor is a piezoelectric accelerometer working based on the piezoelectric effect of a piezoelectric material, when the accelerometer is vibrated, the force of a mass block on a piezoelectric element is changed, when the vibration frequency of the accelerometer is far lower than the natural frequency of the accelerometer, the change of the force is in direct proportion to the measured acceleration, and the piezoelectric material is stressed and deformed in a certain direction to generate charges with the sign opposite to the stress in direct proportion to the stress on two surfaces. Piezoelectric materials are crystalline materials that exhibit charge of opposite sign between two end faces when subjected to pressure, and there are three types of commonly used piezoelectric materials: the first type is an inorganic piezoelectric material, which is divided into a piezoelectric crystal (generally referred to as a piezoelectric single crystal) and a piezoelectric ceramic (generally referred to as a piezoelectric polycrystal), wherein the piezoelectric single crystal refers to a crystal which is grown in a long-range order according to a crystal space lattice, the crystal has piezoelectricity due to the structure without a symmetric center, such as quartz crystal, lithium gallate, lithium germanate, titanium germanate, lithium tantalate and the like, the piezoelectric ceramic is formed by mixing, molding and high-temperature sintering raw materials of necessary components, and fine crystal grains obtained by a solid-phase reaction between powder particles and a sintering process are randomly assembled to form a polycrystal with piezoelectricity, such as barium titanate BT, lead zirconate titanate PZT, modified lead zirconate titanate, lead meta niobate, lead barium lithium niobate PBLN, modified lead titanate PT and the like; the second type is an organic piezoelectric material, also called piezoelectric polymer, which has the advantages of flexible material, low density, low impedance, high voltage constant, etc., such as PVDF (polyvinylidene fluoride) film and other organic piezoelectric film materials represented by the PVDF film; the third type is composite piezoelectric material, which is formed by embedding sheet, rod, bar or powder piezoelectric material into organic polymer base material, and has been widely used in the fields of underwater sound, electroacoustic, ultrasonic, medicine, etc. In comparison, the piezoelectric ceramic has strong piezoelectricity and high dielectric constant, can be processed into any shape, but has lower mechanical quality factor, larger electrical loss and poor stability, so the piezoelectric ceramic is suitable for applications such as high-power transducers, broadband filters and the like, but is not ideal for high-frequency and high-stability applications; quartz and other piezoelectric single crystals are weak in piezoelectricity, low in dielectric constant, limited by cutting type, limited in size, high in stability and high in mechanical quality factor, and are mainly used as oscillators controlled by standard frequency, high-selectivity (mostly belonging to high-frequency narrow-band pass) filters, high-frequency and high-temperature ultrasonic transducers and the like; the PVDF piezoelectric film has unique dielectric effect, piezoelectric effect and thermoelectric effect, has the characteristics of wide frequency response (0-500 MHz), large dynamic range, high force-electricity conversion sensitivity, high mechanical property strength, easy matching of acoustic impedance and the like compared with the traditional piezoelectric material, and has the advantages of light weight, softness, no brittleness, impact resistance, difficulty in being polluted by water and chemicals, easiness in manufacturing sheets or tubes with any shapes and different areas and the like.

In the vibration state monitoring of large-scale rotating electromechanical equipment (such as railway rolling stock), common vibration sensors need to be matched with a power supply line and a measuring line for use, even if an individual power generation type vibration sensor can directly provide a voltage or charge signal, the vibration sensor still needs to be connected with the measuring circuit through a lead, and the measuring circuit also needs to be supported by power supply, so that the monitoring system has poor anti-interference capability, complex structure, large volume and high installation and maintenance cost, and is difficult to meet the application requirements of multi-point decentralized monitoring and real-time monitoring occasions. The vibration energy is an energy form widely existing in the operation of a transmission system, the vibration enables an energy conversion element to generate strain so as to generate electric energy, a typical energy collection mode is adopted, and the mechanical energy in the operation of the transmission system is converted into the electric energy through physical principles such as piezoelectric effect and electromagnetic induction, so that the electric energy can be provided for microelectronic devices such as a wireless sensor.

In order to overcome the defects of the existing vibration state monitoring of the rotary electromechanical device, a vibration energy collector based on the PVDF piezoelectric effect is designed to provide electric energy required by a vibration state monitoring Sensor, and networking is performed by combining a Wireless Sensor Network (WSN), so that the passive Wireless monitoring of the vibration state of the rotary electromechanical device and key components thereof is of great significance.

Disclosure of Invention

The invention discloses a passive wireless vibration monitoring sensor, aiming at overcoming the defects of the existing large-scale rotating electromechanical equipment vibration monitoring sensor.

The technical scheme adopted by the invention is as follows: a passive wireless vibration monitoring sensor is composed of a vibration impact pickup unit (2), a vibration energy collection unit (3) and a signal conditioning and transmitting unit (4) which are packaged in a sensor shell (1), and is installed on a measured part of a rotary electromechanical device, so that the vibration energy can be converted into electric energy while the measured part is subjected to vibration monitoring, and wireless transmission of monitoring signals can be realized without external power supply; the sensor comprises a sensor base (1-5), a sensor shielding cylinder (1-2), a vibration energy collecting unit (3), a signal conditioning and transmitting unit (4), an internal component, an upper cover (1-1) and a lower cover (1-3), wherein the internal component consisting of the vibration impact picking unit (2), the vibration energy collecting unit (3) and the signal conditioning and transmitting unit (4) is arranged on an internal component insulation pad (1-4) in a cavity formed by the sensor base (1-5) and the sensor shielding cylinder (1-2), and is sealed by the upper cover (1-1) of the sensor after being fixedly sealed by an epoxy potting I (1-3); the sensor is connected with the monitoring position of the tested part through the sensor mounting external thread (1-6) in a screwing mode, the vibration impact pickup unit (2), the vibration energy collection unit (3), the negative pole of the signal conditioning and emission unit (4) is communicated with the metal cylinder (5-2), the vibration impact pickup unit (2), the positive pole of the vibration energy collection unit (3) is connected to the signal conditioning and emission unit (4) through a lead respectively, the vibration energy collection unit (3) provides a working power supply for the signal conditioning and emission unit (4), the vibration impact signal of the tested part detected by the vibration impact pickup unit (2) is transmitted to the remote signal acquisition device in a wireless mode after being conditioned by the signal conditioning and emission unit (4), and the passive wireless monitoring of the vibration of the tested part of the rotating electromechanical equipment is realized.

In the application, the sensor shell (1) comprises a sensor upper cover (1-1), a sensor shielding cylinder (1-2), an epoxy encapsulation I (1-3), an internal component insulation pad (1-4), a sensor base (1-5) and a sensor installation external thread (1-6), the sensor is screwed and installed at the monitoring position of a measured part of the rotating electromechanical equipment through the sensor installation external thread (1-6), the sensor base (1-5) is processed into an outer hexagonal shape by adopting a metal material so as to be convenient to install, the sensor shielding cylinder (1-2) is processed into a hollow cylinder by adopting a metal material so as to form a larger internal space and play a role in shielding, the sensor upper cover (1-1) is made of a non-metal material so as to ensure that a wireless signal of a signal conditioning and transmitting unit (4) can be reliably transmitted, the sensor shielding cylinder (1-2) is screwed and connected with the sensor shielding cylinder (1-2) through a thread so as to form a sensor packaging assembly, the internal component is integrally cured by using the epoxy encapsulation I (1-3) after being placed on the internal component insulation pad (1-4) which can be made of machined ceramics so as to ensure that the internal component can be reliably cured and the sensor can be stably operated; the vibration impact pickup unit (2) is arranged in a vibration impact detection cavity (5-6) which is formed by machining a metal cylinder (5-2) and is sealed by crimping a bottom cover (5-10), the vibration energy collection unit (3) is arranged in a vibration energy collection cavity (5-4) which is formed by machining the metal cylinder (5-2) and is sealed by screwing a top cover (5-1), a cavity partition plate (5-8) with a glue filling hole (5-9) is arranged between the vibration energy collection cavity (5-4) and the vibration impact detection cavity (5-6) of the metal cylinder (5-2), the left wall of the vibration energy collection cavity (5-4) is provided with an energy collection wire passing hole (5-5), the right wall of the vibration impact detection cavity (5-6) is provided with a sensing signal wire passing hole II (5-7), and the vibration impact pickup unit (2) and the vibration energy collection unit (3) are arranged on an internal component insulation pad (1-4) after the metal cylinder (5-2) is externally sleeved with a heat shrink tube (5-3).

In the application, the vibration impact pickup unit (2) comprises a crystal support seat (2-1), a piezoelectric ceramic crystal (2-2), a mass block (2-3), a heat shrinkage ring (2-4), a detection unit shield cover (2-5), a detection unit insulating pad (2-6), a detection unit insulating ring (2-7), an epoxy encapsulation II (2-8), an internal heat shrinkage pipe (2-9) and a sensing signal wire through hole I (2-10), wherein the piezoelectric ceramic crystal (2-2) for picking up vibration and impact signals of a detected object is an annular shear crystal, the periphery of the piezoelectric ceramic crystal is annularly wrapped by the mass block (2-3), the piezoelectric ceramic crystal (2-2) and the mass block (2-3) are fastened on the upper part of the crystal support seat (2-1) through the heat shrinkage ring (2-4), the crystal support seat (2-1) and the detection unit shield cover (2-5) with the sensing signal wire through hole I (2-10) form a closed internal piezoelectric ceramic crystal (2-2), and the vibration impact pickup unit (2-2) is formed after the external shielding pipe is wrapped by a material for the insulation shrinkage pipe (9); the vibration impact pickup unit (2) is sleeved with a detection unit insulating ring (2-7) and then is arranged on a detection unit insulating pad (2-6), a bottom cover (5-10) is pressed into a vibration impact detection cavity (5-6), and finally the vibration impact pickup unit (2) is integrally sealed by an epoxy potting II (2-8) through a potting hole (5-9) in a cavity partition plate (5-8); the piezoelectric ceramic crystal (2-2) is PZT-5 of lead zirconate titanate series, the mass block (2-3) is high-density tungsten alloy, the thermal shrinkage ring (2-4) is a low-temperature alloy ring which is made of tin, silver and copper fusible alloy and has the surface covered by a tension larger than 30Mpa, the crystal support seat (2-1) and the detection unit shielding cover (2-5) are all processed by metal materials, the shell of the shielding body is used as the negative pole of a sensing signal, the positive pole of the sensing signal is led out from the thermal shrinkage ring (2-4), and the sensing signal passes through a wire hole I (2-10) on the detection unit shielding cover (2-5) and a sensing signal passes through a wire hole II (5-7) on the right wall of the vibration impact detection cavity (5-6) and then reaches the signal and conditioning and transmitting unit (4).

In the application, the vibration energy collecting unit (3) comprises a vibration energy collecting assembly insulating pad (3-1), a vibration energy collecting assembly positive contact piece (3-2), a lower flexible electrode (3-3), a PVDF stacked group (3-4), an upper flexible electrode (3-5) and a vibration energy collecting assembly negative contact piece (3-6), the PVDF stacked group (3-4) for converting vibration energy into electric energy to supply power for the sensor is formed by stacking a row of circular PVDF piezoelectric film pieces in parallel in a rotary laminating mode, electric charges generated on the PVDF stacked group (3-4) are extracted through the lower flexible electrode (3-3) and the upper flexible electrode (3-5), the vibration energy collecting assembly positive contact piece (3-2) is tightly pressed and connected below the lower flexible electrode (3-3) in a compression mode to serve as a power supply positive electrode, the vibration energy collecting assembly negative contact piece (3-6) is tightly pressed and connected above the upper flexible electrode (3-5) to serve as a power supply negative electrode, a top cover (5-1) is tightly and in contact with the vibration energy collecting assembly negative contact piece (3-6), the vibration energy collecting assembly negative contact piece (5-1) is tightly and is electrically connected with the PVDF stacked group in a clamping mode to enable the whole vibration energy collecting assembly (3-4) to be reliably and connected between the metal stacked cylinder (3-2) in a clamping mode so that the whole cylinder (3-5) and the whole body is fixed to be connected with the vibration energy collecting assembly (3-4) At the central position, a PE material outer heat-shrinkable tube (5-3) for insulation is wrapped outside the metal cylinder (5-2) to form a vibration energy collecting unit (3); the PVDF stacking group (3-4) is formed by stacking a plurality of flexible PVDF piezoelectric thin film sheets with the thickness of 28 micrometers, silver electrodes are plated on two sides of the PVDF thin film sheets, insulating glue is coated on one side of the PVDF thin film sheets to serve as an insulating layer between every two thin film sheets when the PVDF thin film sheets are stacked, the upper flexible electrodes (3-5) and the lower flexible electrodes (3-3) are conductive silica gel sheets, a vibration energy collecting component anode contact sheet (3-2) and a vibration energy collecting component cathode contact sheet (3-6) are thin copper sheets, a top cover (5-1) and a metal cylinder (5-2) are both processed by metal materials, a power supply cathode is led out through the top cover (5-1) and is connected to a signal conditioning and transmitting unit (4) through a metal screw, and a power supply anode is led out through the vibration energy collecting component anode contact sheet (3-2) and then is led to the signal conditioning and transmitting unit (4) through an energy collecting line passing hole (5-5) in the metal cylinder, so that the self-powered sensor in the vibration monitoring process is achieved.

In the application, the signal conditioning and transmitting unit (4) comprises a unit shielding box (4-1) with a power supply wire inlet (4-7) and a detection signal wire inlet (4-8) arranged at the bottom, a signal conditioning and transmitting circuit (4-2), a shielding box upper cover (4-3), a microstrip antenna (4-4), a left fixing screw (4-5) and a right fixing screw (4-6), wherein a detection signal wire is connected to the right end of the signal conditioning and transmitting circuit (4-2) through a sensing signal wire inlet I (2-10), a sensing signal wire inlet II (5-7) and a detection signal wire inlet (4-8), a power line is connected to the left end of the signal conditioning and transmitting circuit (4-2) through an energy collecting wire inlet (5-5) and a power supply wire inlet (4-7), the signal conditioning and transmitting circuit (4-2) is connected to the left end of the signal conditioning and transmitting circuit (4-2), the signal conditioning and transmitting circuit (4-2) and the unit shielding box (4-1) are fixed together through the left fixing screw (4-5) and the right fixing screw (4-6) after the connection is completed, the connection, and the self-powered unit shielding box (4-1) is arranged on the unit shielding box (4-1), and the self-powered unit shielding box (4-1) can be arranged on the rotating shielding box cover (4-1) to form a vibration sensor; a signal conditioning and transmitting circuit (4-2) of each sensor is composed of a high-resistance energy collecting module, a signal amplifying module, a signal modulating module, a signal transmitting module and a local oscillation signal module, in the process of carrying out vibration monitoring on a measured part of rotating electromechanical equipment, a PVDF stack group (3-4) receives vibration energy of the rotating electromechanical equipment, the vibration energy is converted into electric energy required by the working of the sensor through the high-resistance energy collecting module, a piezoelectric ceramic crystal (2-2) picks up vibration and impact signals in the working process of the measured part, the vibration and impact signals are amplified through the signal amplifying module, the amplified vibration and impact signals are modulated with the local oscillation signals in the signal modulating module, the modulated signals are transmitted through a microstrip antenna (4-4) after being subjected to power amplification through the signal transmitting module, a remote signal collecting device demodulates, filters, carries out digital-to-analog conversion and carries out signal processing on the signals transmitted by the sensor, and then the operation state of the measured part of the rotating electromechanical equipment is diagnosed, and passive wireless vibration monitoring of the rotating electromechanical equipment is realized.

The method has the advantages that triple shielding is carried out on the detection unit in the sensor, and double shielding is carried out on the energy collection and detection circuit, so that electromagnetic interference in the operation of the rotating electromechanical equipment is effectively inhibited; the detection element adopts an annular shearing piezoelectric ceramic crystal fixed by a heat-shrinkable ring, so that the problems of temperature drift and working temperature limitation of the existing state monitoring sensor of the rotating electromechanical equipment are solved; the vibration energy collecting assembly formed by stacking a plurality of flexible PVDF piezoelectric thin films can better convert the vibration energy in the operation process of the rotating electromechanical equipment into the electric energy required by the working of the sensor, and the problem that the conventional wireless sensor cannot effectively supply energy is solved; the signal conditioning and transmitting assembly transmits the detection signal in a wireless mode, so that the installation cost of the sensor is reduced, and the problem that the traditional sensor is difficult to wire on the rotary electromechanical equipment is solved.

Drawings

Fig. 1 is a general structural block diagram of the present application.

FIG. 2 is a diagram of a sensor architecture according to an embodiment of the present application;

in the figure: (1) a sensor shell, (2) a vibration impact pickup unit, (3) a vibration energy collection unit, (4) a signal conditioning and transmitting unit, 1-1 a sensor upper cover, 1-2 a sensor shielding cylinder, 1-3 epoxy potting I, 1-4 an internal component insulating pad, 1-5 a sensor base, 1-6 sensor mounting external threads, 2-1 a crystal supporting seat, 2-2 piezoelectric ceramic crystals, 2-3 a mass block, 2-4 a heat shrinkage ring, 2-5 a detection unit shielding cover, 2-6 a detection unit insulating pad, 2-7 a detection unit insulating ring, 2-8 epoxy potting II, 2-9 an internal heat shrinkage pipe, 2-10 a sensing signal wire passing hole I, 3-1 vibration energy collecting component insulating pad, 3-2 vibration energy collecting component anode contact piece, 3-3 lower flexible electrode, 3-4 PVDF stacking group, 3-5 upper flexible electrode, 3-6 vibration energy collecting component cathode contact piece, 4-1 unit shielding box, 4-2 signal conditioning and transmitting circuit, 4-3 shielding box upper cover, 4-4 microstrip antenna, 4-5 left fixing screw, 4-6 right fixing screw, 4-7 power supply wire inlet hole, 4-8 detection signal wire inlet hole, 5-1 top cover, 5-2 metal cylinder, 5-3 external heat shrink tube, 5-4 vibration energy collecting cavity, 5-5 energy collection wire through holes, 5-6 vibration impact detection cavities, 5-7 sensing signal wire through holes II, 5-8 cavity partition plates, 5-9 glue filling holes and 5-10 bottom covers.

Fig. 3 is a block diagram of a signal conditioning and transmitting circuit board according to an embodiment of the present application.

Fig. 4 is a bottom view of a sensor according to an embodiment of the present application.

FIG. 5 is a top view of a sensor according to an embodiment of the present application.

FIG. 6 is a partial cross-sectional view of a sensor according to an embodiment of the present application.

Detailed Description

The technical solution in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application; it is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Referring to the drawings, fig. 1 is a general structural block diagram of the present application, fig. 2 is a structural block diagram of a sensor of an embodiment of the present application, fig. 3 is a block diagram of a signal conditioning and transmitting circuit board of an embodiment of the present application, fig. 4 is a bottom view of a sensor of an embodiment of the present application, fig. 5 is a top view of a sensor of an embodiment of the present application, and fig. 6 is a partial sectional view of a sensor of an embodiment of the present application; in the attached fig. 2: (1) is a sensor shell, (2) is a vibration impact pickup unit, (3) is a vibration energy collection unit, (4) is a signal conditioning and transmitting unit, 1-1 is a sensor upper cover, 1-2 is a sensor shielding cylinder, 1-3 is an epoxy encapsulation I, 1-4 is an internal component insulating pad, 1-5 is a sensor base, 1-6 is a sensor mounting external thread, 2-1 is a crystal supporting base, 2-2 is a piezoelectric ceramic crystal, 2-3 is a mass block, 2-4 is a thermal shrinkage ring, 2-5 is a detection unit shielding cover, 2-6 is a detection unit insulating pad, 2-7 is a detection unit insulating ring, 2-8 is an epoxy encapsulation II, 2-9 is an internal heat shrinkage pipe, and 2-10 is a sensing signal wire through hole I, 3-1 is a vibration energy collecting component insulating pad, 3-2 is a vibration energy collecting component anode contact piece, 3-3 is a lower flexible electrode, 3-4 is a PVDF (polyvinylidene fluoride) stacked group, 3-5 is an upper flexible electrode, 3-6 is a vibration energy collecting component cathode contact piece, 4-1 is a unit shielding box, 4-2 is a signal conditioning and transmitting circuit, 4-3 is a shielding box upper cover, 4-4 is a microstrip antenna, 4-5 is a left fixing screw, 4-6 is a right fixing screw, 4-7 is a power supply wire inlet hole, 4-8 is a detection signal wire inlet hole, 5-1 is a top cover, 5-2 is a metal cylinder, 5-3 is an outer heat shrink tube, 5-4 is a vibration energy collecting cavity, 5-5 is an energy collecting wire inlet hole, 5-6 is a vibration impact detection cavity, 5-7 are sensing signal line through holes II, 5-8 are cavity partition plates, 5-9 are glue filling holes, and 5-10 are bottom covers. For overcoming the defects of the vibration monitoring sensor of the existing large-scale rotating electromechanical equipment: the monitoring signal of the sensor is easily subjected to complex electromagnetic interference in the operation of rotating electromechanical equipment, the temperature drift of a detection element exists, the working temperature is limited, a working power supply needs to be provided outside the sensor, and the detection signal of the sensor is transmitted to a monitoring device in a wired mode; the application discloses be used for passive wireless vibration monitoring sensor. The technical scheme adopted by the application is as follows: the passive wireless vibration monitoring sensor consists of a vibration impact pickup unit (2), a vibration energy collection unit (3) and a signal conditioning and transmitting unit (4) which are packaged in a sensor shell (1), is arranged on a measured part of the rotating electromechanical equipment, can convert vibration energy into electric energy while carrying out vibration monitoring on the measured part, and can realize wireless transmission of monitoring signals without external power supply; the sensor comprises a sensor base (1-5), a sensor shielding cylinder (1-2), a vibration energy collecting unit (3), a signal conditioning and transmitting unit (4), an internal component, an upper cover (1-1) and a lower cover (1-3), wherein the internal component consisting of the vibration impact picking unit (2), the vibration energy collecting unit (3) and the signal conditioning and transmitting unit (4) is arranged on an internal component insulation pad (1-4) in a cavity formed by the sensor base (1-5) and the sensor shielding cylinder (1-2), and is sealed by the upper cover (1-1) of the sensor after being fixedly sealed by an epoxy potting I (1-3); the sensor is connected with the monitoring position of the tested part through the sensor mounting external thread (1-6) in a screwing mode, the vibration impact pickup unit (2), the vibration energy collection unit (3), the negative pole of the signal conditioning and emission unit (4) is communicated with the metal cylinder (5-2), the vibration impact pickup unit (2), the positive pole of the vibration energy collection unit (3) is connected to the signal conditioning and emission unit (4) through a lead respectively, the vibration energy collection unit (3) provides a working power supply for the signal conditioning and emission unit (4), the vibration impact signal of the tested part detected by the vibration impact pickup unit (2) is transmitted to the remote signal acquisition device in a wireless mode after being conditioned by the signal conditioning and emission unit (4), and the passive wireless monitoring of the vibration of the tested part of the rotating electromechanical equipment is realized.

Further, a sensor shell (1) of the sensor comprises a sensor upper cover (1-1), a sensor shielding cylinder (1-2), an epoxy potting I (1-3), an internal component insulating pad (1-4), a sensor base (1-5) and a sensor mounting external thread (1-6), wherein the sensor is screwed and mounted at a monitoring position of a measured part of the rotating electromechanical equipment through the sensor mounting external thread (1-6), the sensor base (1-5) is processed into an outer hexagonal shape by adopting a metal material so as to be convenient to mount, the sensor shielding cylinder (1-2) is processed into a hollow cylinder by adopting a metal material so as to form a larger internal space and play a role in shielding, the sensor upper cover (1-1) is made of a non-metal material so as to ensure that a wireless signal of a signal conditioning and transmitting unit (4) can be reliably transmitted, the sensor shielding cylinder (1-2) is screwed and connected with the sensor shielding cylinder (1-2) through a thread so as to form a sensor packaging assembly, the internal component is integrally cured by using the epoxy potting I (1-3) after being placed on the internal component insulating pad (1-4) which can be made of machinable ceramics, and the internal component is reliably fixed so as to ensure that the sensor can work stably; the vibration and impact pickup unit (2) is arranged in a vibration and impact detection cavity (5-6) which is formed by machining a metal cylinder (5-2) and is sealed by crimping a bottom cover (5-10), the vibration energy collection unit (3) is arranged in a vibration energy collection cavity (5-4) which is formed by machining the metal cylinder (5-2) and is sealed by screwing a top cover (5-1), a cavity partition plate (5-8) with a glue filling hole (5-9) is arranged between the vibration energy collection cavity (5-4) of the metal cylinder (5-2) and the vibration and impact detection cavity (5-6), the left wall of the vibration energy collection cavity (5-4) is provided with an energy collection wire passing hole (5-5), the right wall of the vibration and impact detection cavity (5-6) is provided with a sensing signal wire passing hole II (5-7), and the vibration and impact pickup unit (2) and the vibration energy collection unit (3) are arranged on an external heat shrinkage tube (5-3) and are arranged on an internal component insulation pad (1-4) after the metal cylinder (5-2) is installed. The vibration impact pickup unit (2) comprises a crystal support seat (2-1), a piezoelectric ceramic crystal (2-2), a mass block (2-3), a heat shrinkage ring (2-4), a detection unit shield cover (2-5), a detection unit insulation pad (2-6), a detection unit insulation ring (2-7), an epoxy encapsulation II (2-8), an inner heat shrinkage pipe (2-9) and a sensing signal wire through hole I (2-10), wherein the piezoelectric ceramic crystal (2-2) for picking up vibration and impact signals of a detected object is an annular shear crystal, the periphery of the piezoelectric ceramic crystal is annularly wrapped by the mass block (2-3), the piezoelectric ceramic crystal (2-2) and the mass block (2-3) are fastened on the upper part of the crystal support seat (2-1) through the heat shrinkage ring (2-4), the crystal support seat (2-1) and the detection unit shield cover (2-5) with the sensing signal wire through hole I (2-10) form an inner closed shield body with the piezoelectric ceramic crystal (2-2), and the outer shield body wraps a PE material used for picking up the piezoelectric ceramic crystal (2-2) after the insulation material is wrapped, so that the vibration impact pickup unit (2-9) is formed; the vibration impact pickup unit (2) is sleeved with a detection unit insulating ring (2-7) and then is arranged on a detection unit insulating pad (2-6), a bottom cover (5-10) is pressed into a vibration impact detection cavity (5-6), and finally the vibration impact pickup unit (2) is integrally sealed by an epoxy potting II (2-8) through a potting hole (5-9) in a cavity partition plate (5-8); the piezoelectric ceramic crystal (2-2) is PZT-5 of lead zirconate titanate series, the mass block (2-3) is high-density tungsten alloy, the thermal shrinkage ring (2-4) is a low-temperature alloy ring which is made of tin, silver and copper fusible alloy and has the surface covered by a tension larger than 30Mpa, the crystal support seat (2-1) and the detection unit shielding cover (2-5) are all processed by metal materials, the shell of the shielding body is used as the negative pole of a sensing signal, the positive pole of the sensing signal is led out from the thermal shrinkage ring (2-4), and the sensing signal passes through a wire hole I (2-10) on the detection unit shielding cover (2-5) and a sensing signal passes through a wire hole II (5-7) on the right wall of the vibration impact detection cavity (5-6) and then reaches the signal and conditioning and transmitting unit (4); the annular shear piezoelectric ceramic crystal that this application detecting element adopted to be carried out fixedly by pyrocondensation ring solves the problem of temperature drift, the operating temperature restriction that current rotatory electromechanical device state monitoring sensor exists. The vibration energy collecting unit (3) comprises a vibration energy collecting component insulating pad (3-1), a vibration energy collecting component positive electrode contact piece (3-2), a lower flexible electrode (3-3), a PVDF stacked group (3-4), an upper flexible electrode (3-5) and a vibration energy collecting component negative electrode contact piece (3-6), wherein the PVDF stacked group (3-4) for converting vibration energy into electric energy to supply power to a sensor is formed by stacking a row of circular PVDF piezoelectric film pieces in parallel in a rotary laminating mode, charges generated on the PVDF stacked group (3-4) are extracted through the lower flexible electrode (3-3) and the upper flexible electrode (3-5), the vibration energy collecting component positive electrode contact piece (3-2) is tightly pressed below the lower flexible electrode (3-3) to serve as a power supply positive electrode, the vibration energy collecting component negative electrode contact piece (3-6) is tightly pressed above the upper flexible electrode (3-5) to serve as a power supply, a top cover (5-1) is tightly contacted with the vibration energy collecting component negative electrode contact piece (3-6), the vibration energy collecting component negative electrode contact piece (5-1) is tightly pressed with a metal top cover (5-2) to be tightly pressed above the upper flexible electrode (3-5) to apply pressure to the PVDF stacked group, and the whole vibration energy collecting component is fixed between the PVDF stacked group and the metal top cover (5-1-2) in a flexible electrode stacked group in a reliable clamping mode, and the whole flexible electrode stacked group, and the vibration energy collecting component is fixed between the PVDF stacked group, and the vibration energy collecting component is fixed in a heat collecting component (3-1-4) in a flexible electrode stacked mode, and a heat insulating top cover (3-4) in a whole flexible electrode stacked mode, the metal cylinder (5-2) is wrapped with an outer PE heat-shrinkable tube (5-3) for insulation to form a vibration energy collecting unit (3); the PVDF stacking group (3-4) is formed by stacking a plurality of flexible PVDF piezoelectric thin film sheets with the thickness of 28 micrometers, silver electrodes are plated on two sides of the PVDF thin film sheets, insulating glue is coated on one side of the PVDF thin film sheets to serve as an insulating layer between every two thin film sheets when the PVDF thin film sheets are stacked, the upper flexible electrodes (3-5) and the lower flexible electrodes (3-3) are conductive silica gel sheets, a vibration energy collecting component anode contact sheet (3-2) and a vibration energy collecting component cathode contact sheet (3-6) are thin copper sheets, a top cover (5-1) and a metal cylinder (5-2) are both processed by metal materials, a power supply cathode is led out through the top cover (5-1) and is connected to a signal conditioning and transmitting unit (4) through metal screws, a power supply anode is led out through the vibration energy collecting component anode contact sheet (3-2) and then to the signal conditioning and transmitting unit (4) through an energy collecting line hole (5-5) in the metal cylinder, vibration monitoring of the sensor is achieved, vibration energy in the running process of self-powered electromechanical equipment can be better converted into electric energy required by the existing wireless sensor, and the problem that power supply cannot be effectively achieved. The signal conditioning and transmitting unit (4) comprises a unit shielding box (4-1) with a power supply wire inlet hole (4-7) and a detection signal wire inlet hole (4-8) arranged at the bottom, a signal conditioning and transmitting circuit (4-2), a shielding box upper cover (4-3), a microstrip antenna (4-4), a left fixing screw (4-5) and a right fixing screw (4-6), wherein the detection signal wire passes through a sensing signal wire passing hole I (2-10), a sensing signal wire passing hole II (5-7) and a detection signal wire inlet hole (4-8) and is connected to the right end of the signal conditioning and transmitting circuit (4-2), a power line passes through an energy collecting wire passing hole (5-5) and a power supply wire inlet hole (4-7) and is connected to the left end of the signal conditioning and transmitting circuit (4-2), after connection is completed, the signal conditioning and transmitting circuit (4-2) and the unit shielding box (4-1) are fixed above the top cover (5-1) together through the left fixing screw (4-5) and the right fixing screw (4-6), and the microstrip antenna upper cover (4-1) is arranged on an electromechanical monitoring unit which can simultaneously form a vibration sensor for the microstrip antenna (4-1); the signal conditioning and transmitting circuit (4-2) of each sensor is composed of a high-resistance energy collecting module, a signal amplifying module, a signal modulating module, a signal transmitting module and a local oscillation signal module, in the process of carrying out vibration monitoring on a measured part of rotating electromechanical equipment, a PVDF stack group (3-4) receives vibration energy of the rotating electromechanical equipment, the vibration energy is converted into electric energy required by the working of the sensor through the high-resistance energy collecting module, a piezoelectric ceramic crystal (2-2) picks up vibration and impact signals in the working process of the measured part, the vibration and impact signals are amplified through the signal amplifying module, the amplified vibration and impact signals are modulated with the local oscillation signal in the signal modulating module, the modulated signals are transmitted through a micro-strip antenna (4-4) after being subjected to power amplification through the signal transmitting module, and a remote signal collecting device demodulates, filters, carries out digital-to-analog conversion and processes signals transmitted by the sensor and diagnoses the running state of the measured part of the rotating electromechanical equipment, thereby realizing passive wireless vibration monitoring on the rotating electromechanical equipment; the signal conditioning and transmitting unit (4) transmits the detection signal in a wireless mode, so that the installation cost of the sensor is reduced, and the problem that the traditional sensor is difficult to wire on the rotary electromechanical equipment is solved.

To sum up, the sensor of this application comprises vibration impact pickup unit (2), vibration energy collection unit (3), signal conditioning and transmitting unit (4) of encapsulation in sensor housing (1) inside, installs on rotatory electromechanical device's the part of being surveyed, still can convert vibration energy into the electric energy when carrying out vibration monitoring to the part of being surveyed, need not the wireless transmission that external power just can realize monitoring signal. The detection unit is subjected to triple shielding, the energy collection and detection circuit is subjected to double shielding in the sensor, and electromagnetic interference in the operation of the rotating electromechanical equipment is effectively inhibited; the detection element adopts an annular shearing piezoelectric ceramic crystal fixed by a heat-shrinkable ring, so that the problems of temperature drift and working temperature limitation of the existing state monitoring sensor of the rotating electromechanical equipment are solved; the vibration energy collecting assembly formed by stacking a plurality of flexible PVDF piezoelectric thin films can better convert the vibration energy in the operation process of the rotating electromechanical equipment into the electric energy required by the working of the sensor, and the problem that the conventional wireless sensor cannot effectively supply energy is solved; the signal conditioning and transmitting assembly transmits the detection signal in a wireless mode, the installation cost of the sensor is reduced, and the problem that the traditional sensor is difficult to wire on the rotating electromechanical equipment is solved.

The above description is only for the purpose of illustrating the preferred embodiments of the present application and is not to be construed as limiting the present application, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (5)

1. A passive wireless vibration monitoring sensor is composed of a vibration impact pickup unit, a vibration energy collection unit and a signal conditioning and transmitting unit which are packaged in a sensor shell, is arranged on a measured part of a rotating electromechanical device, can convert vibration energy into electric energy while performing vibration monitoring on the measured part, and can realize wireless transmission of monitoring signals without external power supply; the method is characterized in that: an internal component consisting of a vibration impact pickup unit, a vibration energy collecting unit and a signal conditioning and transmitting unit is arranged on an internal component insulating pad in a cavity formed by a sensor base and a sensor shielding cylinder, and is sealed by an upper cover of the sensor after being fixedly sealed by an epoxy potting I; the sensor passes through the sensor installation external screw thread and connects soon to install the monitoring position at the part of being surveyed, vibration impact pickup unit, the vibration energy collection unit, the negative pole of signal conditioning and transmitting unit is by the metal cylinder intercommunication, vibration impact pickup unit, the positive pole of vibration energy collection unit is connected to signal conditioning and transmitting unit through the wire respectively, the vibration energy collection unit provides working power supply for signal conditioning and transmitting unit, vibration impact pickup unit detects the vibration impact signal of the part of being surveyed and sends remote signal collection system with wireless mode after signal conditioning and transmitting unit are tempered, realized the passive wireless monitoring to the part vibration of being surveyed of rotating electromechanical device.

2. The passive wireless vibration monitoring sensor of claim 1, wherein: the sensor shell comprises a sensor upper cover, a sensor shielding cylinder, an epoxy potting I, an internal component insulating pad, a sensor base and a sensor mounting external thread, wherein the sensor is screwed and mounted at the monitoring position of a measured part of rotary electromechanical equipment through the sensor mounting external thread, the sensor base is processed into an external hexagonal shape by adopting a metal material so as to be convenient to mount, the sensor shielding cylinder is processed into a hollow cylinder by adopting a metal material so as to form a larger internal space and play a role in shielding, the sensor upper cover is made of a non-metal material so as to ensure that a wireless signal of a signal conditioning and transmitting unit can be reliably transmitted, the sensor shielding cylinder and the sensor shielding cylinder are screwed and connected through threads to form a sensor packaging assembly, the internal component is integrally cured by the epoxy potting I after being placed on the internal component insulating pad which can be made of machined ceramics, and is reliably fixed so as to ensure that the sensor can work stably and reliably; the vibration impact pickup unit is installed and is formed by metal cylinder machine tooling, in the vibration impact detection cavity sealed by bottom crimping, the vibration energy collection unit is installed and is formed by metal cylinder machine tooling, in the vibration energy collection cavity sealed by top cap rotary joint, the vibration energy collection cavity of metal cylinder, set up the cavity baffle that has the encapsulating hole between the vibration impact detection cavity, it crosses the line hole to be provided with the energy collection on the left wall of vibration energy collection cavity, it crosses line hole II to be provided with the sensing signal on the right wall of vibration impact detection cavity, the vibration impact pickup unit, the vibration energy collection unit installs and adds the external pyrocondensation pipe of cover and places in on the inside subassembly insulation pad outside the metal cylinder after accomplishing.

3. The passive wireless vibration monitoring sensor of claim 1, wherein: the vibration impact pickup unit comprises a crystal support seat, a piezoelectric ceramic crystal, a mass block, a heat shrinkage ring, a detection unit shielding case, a detection unit insulating pad, a detection unit insulating ring, an epoxy potting II, an internal heat shrinkage pipe and a sensing signal wire through hole I, wherein the piezoelectric ceramic crystal for picking up vibration and impact signals of a detected object is an annular shear crystal, the periphery of the piezoelectric ceramic crystal is annularly wrapped by the mass block, the piezoelectric ceramic crystal and the mass block are fastened on the upper part of the crystal support seat through the heat shrinkage ring, the crystal support seat and the detection unit shielding case with the sensing signal wire through hole I form a closed internal shielding body with the piezoelectric ceramic crystal inside, and the vibration impact pickup unit is formed after the PE internal heat shrinkage pipe for insulation is wrapped outside the shielding body; the vibration impact pickup unit is sleeved with a detection unit insulating ring and then is arranged on a detection unit insulating pad, then a bottom cover is in compression joint with the inside of the vibration impact detection cavity, and finally the whole vibration impact pickup unit is fixedly sealed by an epoxy potting II through a glue filling hole on a cavity partition plate; the piezoelectric ceramic crystal is PZT-5 of lead zirconate titanate series, the mass block is high-density tungsten alloy, the heat-shrinkable ring is a low-temperature alloy ring which is made of tin, silver and copper fusible alloy and has a surface covered by a tension larger than 30Mpa, the crystal supporting seat and the detection unit shielding cover are all made of metal materials, the shell of the shielding body is used as the cathode of a sensing signal, the anode of the sensing signal is led out of the heat-shrinkable ring, and the sensing signal passes through a wire passing hole I on the detection unit shielding cover and a wire passing hole II on the right wall of the vibration impact detection cavity and then reaches the signal conditioning and transmitting unit.

4. The passive wireless vibration monitoring sensor of claim 1, wherein: the vibration energy collecting unit comprises a vibration energy collecting component insulating pad, a vibration energy collecting component anode contact piece, a lower flexible electrode, a PVDF (polyvinylidene fluoride) stacking group, an upper flexible electrode and a vibration energy collecting component cathode contact piece, wherein the PVDF stacking group for converting vibration energy into electric energy to supply power to the sensor is formed by parallelly stacking a row of circular PVDF piezoelectric film pieces in a rotary laminating mode; the PVDF stacking group is formed by stacking a plurality of flexible PVDF piezoelectric film sheets with the thickness of 28 microns, silver electrodes are plated on two sides of the PVDF film sheets, insulating glue is coated on one side of the upper side of the PVDF film sheets to serve as an insulating layer between every two film sheets during stacking, the upper flexible electrode and the lower flexible electrode are conductive silica gel sheets, a vibration energy collecting component positive electrode contact sheet and a vibration energy collecting component negative electrode contact sheet are thin copper sheets, a top cover and a metal cylinder are made of metal materials, a power supply negative electrode is led out through the top cover and is connected to a signal conditioning and transmitting unit through a metal screw, a power supply positive electrode is led out through the vibration energy collecting component positive electrode contact sheet and is led out through an energy collecting wire passing hole in the metal cylinder to the signal conditioning and transmitting unit, and self-powering of the sensor in the vibration monitoring process is achieved.

5. The passive wireless vibration monitoring sensor of claim 1, wherein: the signal conditioning and transmitting unit comprises a unit shielding box, a signal conditioning and transmitting circuit, a shielding box upper cover, a micro-strip antenna, a left fixing screw and a right fixing screw, wherein a power supply wire inlet hole and a detection signal wire inlet hole are formed in the bottom of the unit shielding box, the detection signal wire passes through a sensing signal wire passing hole I, a sensing signal wire passing hole II and a detection signal wire inlet hole and is connected to the right end of the signal conditioning and transmitting circuit, a power supply wire passes through an energy collecting wire passing hole and the power supply wire inlet hole and is connected to the left end of the signal conditioning and transmitting circuit, the signal conditioning and transmitting circuit and the unit shielding box are fixed above the top cover together through the left fixing screw and the right fixing screw after connection is completed, and then the shielding box upper cover of the upper micro-strip antenna is arranged above the unit shielding box to form a wireless sensor capable of self-powering while carrying out vibration monitoring on the rotating electromechanical equipment; the signal conditioning and transmitting circuit of each sensor comprises a high-resistance energy collecting module, a signal amplifying module, a signal modulating module, a signal transmitting module and a local oscillation signal module, in the process of carrying out vibration monitoring on a part to be detected of the rotating electromechanical equipment, a PVDF (polyvinylidene fluoride) stack group receives vibration energy of the rotating electromechanical equipment, the vibration energy is converted into electric energy required by the working of the sensor through the high-resistance energy collecting module, a piezoelectric ceramic crystal picks up vibration and impact signals in the working process of the part to be detected and amplifies the vibration and impact signals through the signal amplifying module, the amplified vibration and impact signals are modulated with the local oscillation signals in the signal modulating module, the modulated signals are transmitted through a microstrip antenna after being subjected to power amplification through the signal transmitting module, and a remote signal collecting device demodulates, filters, converts digital-analog conversion and processes the signals transmitted by the sensor and diagnoses the running state of the part to be detected of the rotating electromechanical equipment, so that passive wireless vibration monitoring on the rotating electromechanical equipment is realized.

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