A device for detecting metal shavings in lubricating oil

Abstract

This invention discloses a lubricating oil metal shavings detection device, including an oil shavings separator connected to a sliding pipeline. A shavings sensor is installed on one side of the oil shavings separator, and the shavings sensor is connected to a shavings conditioner via a cable. The oil shavings separator can place metal shavings and lubricating oil in the lubricating oil below the shavings sensor and expel air from the lubricating oil from the top. The shavings sensor generates an induced voltage based on the metal shavings detected below and transmits the induced voltage signal to the shavings conditioner via the cable. The shavings conditioner can collect the number and size of the shavings based on the induced voltage transmitted by the shavings sensor and transmit this information to a host computer. In this invention, the shavings sensor uses a permanent magnet as the magnet, which can generate a stable magnetic field, has strong anti-interference ability against electromagnetic fields, and has more stable performance. The induced voltage in the induction coil is enhanced by increasing the lubricating oil flow rate. The entire device is a mechanical structure and is not affected by aircraft electromagnetic interference.

Description

Technical Field

[0001] This invention relates to the field of aircraft engine debris detection technology, specifically to a device for detecting lubricating oil metal debris. Background Technology

[0002] The content of metal shavings in aircraft engine lubricating oil reflects the wear condition of the engine's rotating mechanical parts. Measuring the size and quantity of metal shavings in engine lubricating oil can reveal the working condition of the engine's rotating mechanical parts.

[0003] Currently, lubricating oil metal shavings detection devices are divided into several types: sampling detection type, adsorption type, electromagnetic induction type, etc.

[0004] The sampling and testing method involves aircraft ground maintenance personnel periodically collecting lubricating oil samples, sending them to a laboratory for analysis using physicochemical methods such as spectroscopy, and then sending the results back to ground maintenance personnel for decision-making. This testing method has advantages such as high detection accuracy and the ability to detect a wide variety of particles, but it also has drawbacks such as long testing time, large random sampling errors, and the inability to perform online testing.

[0005] Adsorption-type detection uses magnets or electromagnetic fields to attract debris within the lubricating oil lines. This method allows for online detection, but it cannot measure the size of individual debris particles and requires periodic cleaning.

[0006] The electromagnetic induction type involves winding two energized excitation coils around a lubricating oil line, creating a stable magnetic field. An induction coil is wound within this magnetic field. Metal shavings passing through the magnetic field cause a change in magnetic flux, inducing a voltage in the induction coil. The amplitude of this voltage is directly proportional to the size of the shavings. This method can measure metal shavings online with high accuracy. However, during flight, it suffers from problems such as poor accuracy, no signal output, and susceptibility to false alarms due to vibrations and electromagnetic interference. Summary of the Invention

[0007] The purpose of this invention is to provide a lubricating oil metal shavings detection device with strong anti-interference ability and more stable performance.

[0008] This invention is achieved through the following technical solution: a lubricating oil metal shavings detection device, including an oil shavings separator connected to the engine sliding pipe, a shavings sensor installed on one side of the oil shavings separator, the shavings sensor being connected to a shavings conditioner via a cable, the oil shavings separator placing the metal shavings and lubricating oil in the lubricating oil below the shavings sensor on one side, and discharging air from the lubricating oil from the top, the shavings sensor generating an induced voltage based on the metal shavings detected below, and transmitting the induced voltage signal to the shavings conditioner via the cable, the shavings conditioner collecting the number and size of the shavings based on the induced voltage transmitted by the shavings sensor, and transmitting it to a host computer.

[0009] The working principle of this technical solution is as follows: Based on the effects of eddy currents and centrifugal force, after the lubricating oil enters the oil-dander separator, the gas, due to its density and mass, will first be discharged from the top. The lubricating oil will accelerate as it passes through the eddy current tube, and metal shavings will be thrown out at high speed into the shavings sensor. According to the principle of electromagnetic induction, a change in magnetic flux in the induction coil will generate an induced voltage. The magnitude of the induced voltage is related to the rate of change of magnetic flux and the number of turns of the induction coil. After the metal shavings enter the magnetic field, magnetic shavings will magnetize and strengthen the magnetic field, while non-magnetic shavings will weaken the magnetic field. Based on the above principles: when the oil-dander separator throws shavings through the shavings sensor, the shavings strengthen or weaken the magnetic field, causing a change in magnetic flux and generating an induced voltage in the induction coil. The induced voltage is transmitted through a cable to the shavings conditioner, where it is amplified, compared, and then normally acquired. The number of waveforms corresponds to the number of shavings, the amplitude corresponds to the size of the shaving particles, and the waveform shape corresponds to the type of shavings.

[0010] To better realize the present invention, the oil-dander separator further includes a body, a gas outlet at the top of the body, an oil inlet communicating with the interior of the body, the oil inlet being connected to the engine sliding pipe, a flow divider blade at the lower part of the oil inlet inside the body, a vortex tube below the flow divider blade, an outwardly protruding dander sensing area inside the body on the outlet side of the vortex tube, an installation port for installing a dander sensor above the dander sensing area, and an oil outlet communicating with an external oil pipe at the body directly below the vortex tube.

[0011] To better realize the present invention, the height of the dust sensing area is 3-8 mm, and the distance between the dust sensor and the dust sensing area is 5-10 mm.

[0012] To better realize the present invention, the dust sensor further includes a housing, in which a magnet and an iron core are installed and connected to each other, and an induction coil is wound on the iron core.

[0013] To better realize the present invention, the debris conditioner further includes an amplification circuit, a filtering circuit, a voltage comparison circuit, and a timing circuit connected in sequence. The amplification circuit receives the induced voltage signal transmitted by the debris sensor and amplifies the received induced voltage signal. The filtering circuit filters out noise generated by electromagnetic interference, etc. The voltage comparison circuit compares the amplified sensor output voltage with a reference voltage and discards signals that are lower than the reference voltage to reduce false alarms. The timing circuit transmits the collected number of debris and debris size to the host computer at regular intervals.

[0014] To better realize the present invention, a test coil is further wound on the iron core, and the dust conditioner is further provided with an excitation circuit. The excitation circuit can generate an excitation signal to generate a magnetic field in the self-test coil to change the magnetic flux in the induction coil and generate a self-test induced electromotive force.

[0015] To better realize the present invention, the cable is further described as a multi-layer shielded cable and is connected to the shaving conditioner via a plug.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0017] (1) In this invention, the debris sensor uses a magnet as a permanent magnet, which can generate a stable magnetic field. It has strong anti-interference ability compared to electromagnetic fields and its performance is more stable when the aircraft engine is working.

[0018] (2) The present invention uses the method of increasing the flow rate of lubricating oil to enhance the induced voltage in the induction coil. Compared with increasing the frequency of electromagnetic field excitation signal to enhance the induced voltage in the induction coil, it is all mechanical structure and will not be affected by electromagnetic interference from aircraft.

[0019] (3) In the process of signal transmission, the present invention uses the same wire to directly connect the induction coil to the chip conditioner plug. By eliminating the connection of a plug and socket, the unstable voltage loss of about 1mV of the connector is reduced, thereby improving the accuracy.

[0020] (4) The present invention adds a self-test coil. This device is used for engine safety management. Under normal operation, there is generally no signal output. Self-testing can ensure normal product performance. Attached Figure Description

[0021] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0022] Figure 1 This is a structural block diagram of the present invention;

[0023] Figure 2 This is a three-dimensional structural diagram of the oil-dandruff separator in this invention;

[0024] Figure 3 This is a schematic cross-sectional view of the oil shavings sensor in this invention;

[0025] Figure 4 This is a schematic cross-sectional view of the debris sensor in this invention;

[0026] Figure 5 This is a partial structural schematic diagram of the present invention;

[0027] Figure 6This is a schematic diagram of the circuit principle of the dust conditioner in this invention;

[0028] Figure 7 This is a schematic diagram of the detected debris output signal in Embodiment 8 of the present invention;

[0029] Figure 8 This is a schematic diagram of the output signal during self-test in Embodiment 8 of the present invention.

[0030] Wherein: 1—oil and debris separator, 11—body, 12—gas outlet, 13—lubricating oil inlet, 14—diverter blade, 15—vortex tube, 16—dandruff sensing area, 17—lubricating oil outlet, 2—dandruff sensor, 21—shell, 22—magnet, 23—iron core, 24—induction coil, 3—cable, 4—plug. Detailed Implementation

[0031] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0032] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] Example 1:

[0035] The main structure of this embodiment is as follows: Figure 1As shown, the device includes an oil-shavings separator 1 connected to the engine sliding pipe. A shavings sensor 2 is installed on one side of the oil-shavings separator 1. The shavings sensor 2 is connected to a shavings conditioner via a cable 3. The oil-shavings separator 1 can place metal shavings and lubricating oil in the lubricating oil below the shavings sensor 2 and discharge air from the lubricating oil from the top. The shavings sensor 2 generates an induced voltage based on the metal shavings detected below and transmits the induced voltage signal to the shavings conditioner via the cable. The shavings conditioner can collect the number and size of the shavings based on the induced voltage transmitted by the shavings sensor 2 and transmit it to the host computer.

[0036] The specific implementation process is as follows: the oil-shaving separator 1 can place the metal shavings and lubricating oil in the lubricating oil below the shaving sensor 2 on one side, and discharge the air in the lubricating oil from the top. The shaving sensor 2 generates an induced voltage based on the metal shavings sensed below, and transmits the induced voltage signal to the shaving conditioner through a cable. The shaving conditioner can collect the number and size of the shavings based on the induced voltage transmitted by the shaving sensor 2, and transmit it to the host computer.

[0037] Example 2:

[0038] This embodiment further defines the structure of the oil-dander separator 1 based on the above embodiments, such as... Figure 2 , Figure 3 As shown, the oil-dander separator 1 includes a body 11, a gas outlet 12 at the top of the body 12, an oil inlet 13 communicating with the interior of the body 11, the oil inlet 13 being connected to the engine sliding pipe, a flow divider blade 14 being provided at the lower part of the oil inlet 13 inside the body 11, a vortex tube 15 being provided below the flow divider blade 14, an outwardly protruding dander sensing area 16 being provided inside the body 11 on the outlet side of the vortex tube 15, an installation port for installing a dander sensor 2 being provided above the dander sensing area 16, and an oil outlet 17 communicating with an external oil pipe being provided at the body 11 directly below the vortex tube 15.

[0039] In the oil-shavings separator 1, the lubricating oil inlet 13 is the inlet for lubricating oil, metal shavings, air, and other gases, and is connected to the engine's lubricating oil pipeline. The gas outlet 12 is the outlet for all separated gases, and is located at the top of the oil-shavings separator 1. The lubricating oil outlet 13 is the outlet for separated lubricating oil, located at the bottom of the oil-shavings separator 1. The mounting port for the dust sensor 2 is used to install the dust sensor 2, and has an internal self-closing valve that automatically closes to prevent oil leakage when the sensor is not installed. The sensor mounting port is located on the side of the oil-shavings separator, at the point where the lubricating oil's rotational flow speed is the fastest. The vortex tube 15 utilizes the vortex effect of the liquid; the lubricating oil enters the vortex tube and rotates downwards, continuously accelerating until it reaches its maximum speed at the dust sensor. Metal shavings and some lubricating oil are thrown out due to centrifugal force, passing below the dust sensor, which then collects the signal. In addition, the diverter blade 14 ensures that the lubricating oil entering the body 11 accurately enters the vortex tube 15. Other parts of this embodiment are the same as those in the above embodiment and will not be described again.

[0040] Example 3:

[0041] This embodiment further defines the structure of the oil-dander separator 1 based on the above embodiments, such as... Figure 2 , Figure 3 As shown, the height of the dust sensing area 16 is 3-8 mm, and the distance between the dust sensor 2 and the dust sensing area is 5-10 mm. The dimensions of the sensing area in the Y-axis direction should be appropriately controlled to ensure that the magnetic field strength of the permanent magnet of the dust sensor is basically the same in the Y-axis direction of the sensing area. Through extensive experiments, the height and distance of the dust sensing area 16 are limited to ensure accurate dust sensing. Other parts of this embodiment are the same as those in the above embodiments and will not be repeated.

[0042] Example 4:

[0043] This embodiment further defines the structure of the debris sensor 2 based on the above embodiments, such as... Figure 4 , Figure 5 As shown, the debris sensor 2 includes a housing 21, within which a magnet 22 and an iron core 23 are installed and connected to each other. An induction coil 24 is wound around the iron core 23. The magnet generates a stable magnetic field in the lubricating oil debris. The magnetization of the iron core enhances the magnetic field strength in the lubricating oil debris. When the lubricating oil debris moves in the magnetic field generated by the magnet and the iron core, an induced voltage is generated in the induction coil. The connecting cable connects the induction coil to the debris conditioner. The connecting cable is a multi-layer shielded cable. No connector is used at the debris sensor end; the connection is directly from the induction coil to the debris conditioner. Other parts of this embodiment are the same as those in the above embodiment and will not be described again.

[0044] Example 5:

[0045] This embodiment further defines the structure of the shavings conditioner based on the above embodiments, such as... Figure 6 As shown, the debris conditioner includes an amplifier circuit, a filter circuit, a voltage comparison circuit, and a timing circuit connected in sequence. The amplifier circuit receives the induced voltage signal transmitted by the debris sensor 2 and amplifies the received induced voltage signal. The filter circuit filters out noise generated by electromagnetic interference, etc. The voltage comparison circuit compares the amplified sensor output voltage with a reference voltage, discarding signals lower than the reference voltage to reduce false alarms. The timing circuit periodically transmits the collected number and size of debris to the host computer. Other parts of this embodiment are the same as those in the above embodiment and will not be described again.

[0046] Example 6:

[0047] This embodiment further defines the structure of the shavings conditioner based on the above embodiments, such as... Figure 6 As shown, a test coil is also wound around the iron core 23, and the dust conditioner is further provided with an excitation circuit. The excitation circuit can generate an excitation signal to produce a magnetic field in the self-test coil, thereby changing the magnetic flux in the induction coil 24 to generate a self-test induced electromotive force. The test coil is used for self-testing; the excitation signal generated by the dust conditioner generates a magnetic field in the self-test coil, thereby changing the magnetic flux in the induction coil to generate a self-test induced electromotive force. The other parts of this embodiment are the same as those in the above embodiment and will not be described again.

[0048] Example 7:

[0049] This embodiment further defines the connection structure based on the above embodiments, such as... Figure 5 As shown, cable 3 is a multi-layer shielded cable and is connected to the debris conditioner via plug 4. During signal transmission, the induction coil is directly connected to the debris conditioner plug using the same wire. By eliminating the connection of one plug and socket, the unstable voltage loss of approximately 1mV in the connector is reduced, thereby improving accuracy. Other parts of this embodiment are the same as those in the above embodiment and will not be described again.

[0050] Example 8:

[0051] This embodiment provides an example of a lubricating oil metal shavings detection device, comprising an oil shavings separator, a shavings sensor, and a shavings conditioner. After the lubricating oil is accelerated by the eddy current tube in the oil shavings separator, the minimum rotational speed of the ejected metal shavings is 5000 r / min. The shavings reach the shavings sensing area, and the dimensions of the sensing area along the Y-axis should be appropriately controlled to ensure that the magnetic field strength of the permanent magnet of the shavings sensor is basically the same along the Y-axis of the sensing area. In this invention, the height of the sensing area along the Y-axis is 4.5 mm, and the distance between the shavings sensor and the sensing area is 8 mm. Under this design, magnetic shavings with a diameter of 0.125 mm can be identified, with a sensor output voltage amplitude of approximately 12 mV; non-magnetic shavings with a diameter of 0.4 mm can be identified, with a sensor output voltage amplitude of approximately 14 mV. The sensor-induced voltage signal is transmitted to the shavings conditioner, and after filtering and amplification, as shown... Figure 7 As shown, its output voltage range is 1V to 8.5V, corresponding to magnetic debris diameters of 0.125mm to 1mm and non-magnetic debris diameters of 0.4mm to 3mm. The debris conditioner is designed with a self-testing square wave excitation signal, such as... Figure 8 As shown, its amplitude is 4.5V and its period is 1.1ms. During self-test, the output voltage amplitude of the dust sensor is greater than 37mV.

[0052] This invention achieves a detection rate of over 95% for the smallest debris size in a laboratory environment and over 80% for the smallest debris size when the engine is operating normally. It also achieves a detection rate of over 95% for magnetic debris larger than 0.3 mm and non-magnetic debris larger than 0.6 mm.

[0053] It is understood that the working principle and process of the lubricating oil metal shavings detection device structure according to an embodiment of the present invention, such as the magnet 22 and the eddy current tube 15, are existing technologies and are well known to those skilled in the art, and will not be described in detail here.

[0054] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A device for detecting metal shavings in lubricating oil, characterized in that, The system includes an oil-shavings separator (1) connected to the engine sliding pipe. A shavings sensor (2) is installed on one side of the oil-shavings separator (1). The shavings sensor (2) is connected to a shavings conditioner via a cable (3). The oil-shavings separator (1) can place metal shavings and lubricating oil below the shavings sensor (2) on one side and discharge air from the lubricating oil from the top. The shavings sensor (2) generates an induced voltage based on the metal shavings sensed below and transmits the induced voltage signal to the shavings conditioner via a cable. The shavings conditioner can collect the number and size of shavings based on the induced voltage transmitted by the shavings sensor (2) and transmit it to a host computer. The oil-shavings separator (1) includes a body (11). A gas outlet (12) is provided at the top of the body (11). The body (11) is equipped with a... The body (11) has an internal oil inlet (13) that is connected to the engine sliding pipe. The lower part of the oil inlet (13) inside the body (11) is provided with a flow divider blade (14). A vortex tube (15) is provided below the flow divider blade (14). A debris sensing area (16) protruding outward is provided inside the body (11) on the side of the outlet of the vortex tube (15). An installation port for installing a debris sensor (2) is provided above the debris sensing area (16). An oil outlet (17) connected to an external oil pipe is provided at the body (11) directly below the vortex tube (15). The debris sensor (2) includes a housing (21). A magnet (22) and an iron core (23) connected to each other are installed inside the housing (21). An induction coil (24) is wound on the iron core (23).

2. The lubricating oil metal shavings detection device according to claim 1, characterized in that, The height of the dust sensing area (16) is 3~8mm, and the distance between the dust sensor (2) and the dust sensing area is 5~10mm.

3. The lubricating oil metal shavings detection device according to claim 1, characterized in that, The debris conditioner includes an amplifier circuit, a filter circuit, a voltage comparison circuit, and a timing circuit connected in sequence. The amplifier circuit receives the induced voltage signal transmitted by the debris sensor (2) and amplifies the received induced voltage signal. The filter circuit filters out noise generated by electromagnetic interference. The voltage comparison circuit compares the amplified sensor output voltage with the reference voltage and discards signals that are less than the reference voltage to reduce false alarms. The timing circuit transmits the number and size of debris collected to the host computer at regular intervals.

4. The lubricating oil metal shavings detection device according to claim 3, characterized in that, The iron core (23) is also wound with a test coil, and the dust conditioner is also provided with an excitation circuit. The excitation circuit can generate an excitation signal to generate a magnetic field in the test coil to change the magnetic flux in the induction coil (24) and generate a self-test induced electromotive force.

5. A device for detecting lubricating oil metal shavings according to any one of claims 1 to 4, characterized in that, The cable (3) is a multi-layer shielded cable and is connected to the slag conditioner via a plug (4).

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