Magnetoelectric rotating speed sensor

Abstract

The utility model provides a magnetoelectric tachometric transducer, which comprises a permanent magnet extending along the axial direction, a framework positioned on the periphery of the permanent magnet, a coil wound on the periphery of the framework and a shell coated outside the coil, and in the axial direction of the permanent magnet, the coil is positioned on the periphery of the permanent magnet. According to the magnetoelectric tachometric transducer, the effective output amplitude of the phonic wheel under the condition of low rotating speed is ensured, meanwhile, the effective output of the transducer can meet the acquisition requirement under the condition of large measurement gap, and the magnetoelectric tachometric transducer is simpler and more compact in structure and lower in cost.

Description

[Technical Field]

[0001] This utility model relates to a sensor. In particular, it relates to a magnetoelectric speed sensor. [Background Technology]

[0002] An aero engine is a complex power unit that operates under high temperature, high rotation, and high vibration conditions. During operation, it is subjected to harsh environments of high temperature and strong vibration, which places high reliability requirements on all devices installed on the equipment.

[0003] A key indicator for monitoring the operating status of aero engines is engine speed, which is primarily acquired through speed sensors. However, the complex environment of aero engines—characterized by high temperatures, high vibrations, and high speeds—makes many sensors unsuitable for this environment, including Hall effect speed sensors commonly found in automotive engines.

[0004] Traditional magnetoelectric sensors primarily measure rotational speed based on Faraday's law of electricity generation. The approximate formula for their output voltage is:

[0005] E≈60 g / N·B·A·Z·Δg·n

[0006] Where: E: Output voltage (volts, V)

[0007] N: Number of coil turns (dimensionless)

[0008] B: Magnetic flux density (Tesla, T), provided by the permanent magnet.

[0009] A: Cross-sectional area of ​​magnetic circuit (square meters, m²) 2 )

[0010] Z: Number of teeth on the gear (dimensionless)

[0011] Δg: Change in air gap (meters, m), caused by the alternation of gear teeth and clearance.

[0012] n: Rotational speed (revolutions per minute, rpm)

[0013] g: Average measurement gap d1 (meters, m)

[0014] Its structure is shown in the appendix. Figure 1As shown, the sensor mainly consists of a multi-turn coil 4 formed by winding enameled wire around a non-metallic frame 3. An iron core 5 is inserted inside the frame 3, and a permanent magnet 6 is installed at the rear end of the iron core 5, creating a uniform and constant magnetic field environment within the coil 4. When an external magnetic metal passes near the coil 4, a cutting magnetic induction phenomenon occurs, resulting in an induced voltage within the coil 4. The frequency of this induced voltage change is the product of the number of external magnetic materials and the rotational speed. By statistically analyzing the frequency of the induced voltage within the coil 4, the rotational speed of the rotating body can be equivalently calculated. In use, it is generally used in conjunction with a tone wheel 1, which is mounted on the shaft being measured. For example, a gear tone wheel can be used. During rotation, the tooth tips and grooves alternately pass through the sensor, causing alternating changes in the magnetic flux of the sensor coil 4, resulting in an output signal. Due to its relatively basic internal components and high overall temperature resistance, it has a wide range of applications in the field of aero-engines.

[0015] from Figure 1 As can be seen, the commonly used structure of this type of magnetoelectric sensor includes a shell 2, a frame 3, a coil 4, an iron core 5, a permanent magnet 6, and wires. The iron core is located inside the frame 3 at the corresponding position of the coil 4, and the permanent magnet 6 is located at one end of the iron core, i.e., outside the coil 4. During actual installation, it is necessary to ensure that the front end of the sensor and the measured sound wheel 1 are separated by a distance to prevent the sound wheel 1 from deforming at high speed or high temperature, colliding with the sensor, and thus damaging it. This distance is generally called the measurement gap d1. Theoretically, the smaller the measurement gap d1, the larger the sensor output voltage, and the easier it is for the downstream acquisition system to acquire the rotational speed signal. However, considering the extreme operating conditions in actual use, the measurement gap d1 of the rotational speed sensor in current aero-engines is generally specified to be 0.5–1 mm.

[0016] However, this type of speed sensor will encounter the following problems in practical engineering applications:

[0017] (1) Under low speed conditions, the disturbance change of the magnetic induction intensity inside the sensor by the sound wheel 1 is slow, and the amplitude of the sensor output signal is too weak, making it difficult for the back-end acquisition system to accurately acquire the engine speed. In the early engine development process, the speed measurement under low engine speed conditions was generally not a focus, but with the development of new technologies, the current requirements for speed measurement under low speed conditions have been raised.

[0018] (2) Due to the structural requirements of new aero-engines, some engines require a significant increase in the measurement gap d1, from no more than 1 mm to no less than 10 mm. This increase in the measurement gap d1 will significantly reduce the sensor output under the same isodynamic rotational speed, potentially resulting in no signal at all, thus failing to meet the requirements for measuring engine speed.

[0019] Therefore, it is necessary to improve the magnetoelectric sensor to ensure the effective output amplitude of the sound wheel 1 under low speed conditions, while also ensuring that the effective output of the sensor can meet the data acquisition requirements under large measurement gap d1 conditions, in order to adapt to the needs of aerospace equipment applications. [Utility Model Content]

[0020] The purpose of this invention is to provide a magnetoelectric speed sensor that ensures effective output amplitude under low-speed conditions of the sound wheel, and also ensures that the effective output of the sensor can meet the acquisition requirements under large measurement gap conditions. Furthermore, the structure of this magnetoelectric speed sensor is simpler and more compact, and the cost is lower.

[0021] To achieve the above-mentioned utility model objectives, this utility model provides a magnetoelectric speed sensor, wherein the magnetoelectric speed sensor includes a permanent magnet extending along the axial direction, a frame located on the outer periphery of the permanent magnet, a coil wound around the outer periphery of the frame, and a shell covering the coil, and the coil is located on the outer periphery of the permanent magnet along the axial direction of the permanent magnet.

[0022] As a further improvement of one embodiment of the present invention, the coil extends from both ends of the permanent magnet along the axial direction of the permanent magnet.

[0023] As a further improvement of one embodiment of the present invention, one end of the permanent magnet extends out of the outer shell along the axial direction of the permanent magnet.

[0024] As a further improvement of one embodiment of the present invention, in the axial direction of the permanent magnet, the other end of the permanent magnet is flush with the end of the skeleton.

[0025] As a further improvement of one embodiment of the present invention, the outer circumference of the permanent magnet is set to be uniform throughout the entire axial direction.

[0026] As a further improvement of one embodiment of the present invention, the material of the permanent magnet is neodymium iron boron.

[0027] As a further improvement of one embodiment of the present invention, the material of the permanent magnet is samarium cobalt.

[0028] As a further improvement of one embodiment of the present invention, the magnetoelectric speed sensor is used to measure the speed of the tone wheel. The tone wheel is provided with a strong magnet, and the polarity of the exposed magnetic pole of the strong magnet is opposite to that of the magnetic pole of the permanent magnet facing the end of the tone wheel.

[0029] As a further improvement of one embodiment of the present invention, the strong magnet is disposed on the teeth of the tone wheel.

[0030] As a further improvement of one embodiment of the present invention, each tooth of the sound wheel is provided with a strong magnet.

[0031] Compared with existing technologies, this invention has the following advantages: The technical solution provided by this invention involves placing the coil on the outer periphery of the permanent magnet along its axial direction, enabling the permanent magnet to generate a sufficiently strong magnetic field over a considerable distance from the sensor's measuring end face. When the measured tone wheel is slowly disturbed, a sufficiently large magnetomotive force (EMF) is generated within the induction coil inside the sensor, resulting in a significant increase in the peak output EMF of the magnetoelectric speed sensor. Alternatively, when the measurement gap between the measured tone wheel and the magnetoelectric speed sensor reaches 10mm or even higher, the magnetoelectric speed sensor can also generate an induced EMF of a certain amplitude, thus meeting the acquisition requirements of the backend acquisition system. Therefore, this magnetoelectric sensor ensures an effective output amplitude under low tone wheel speed conditions, while also ensuring that the effective output of the sensor meets acquisition requirements under large measurement gap conditions. Furthermore, the magnetoelectric speed sensor has a simpler and more compact structure and lower cost. [Attached Image Description]

[0032] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0033] Figure 1 This is a schematic diagram of the structure of a speed sensor in the prior art;

[0034] Figure 2 This is a front view of the magnetoelectric speed sensor of this utility model;

[0035] Figure 3 This is a front view of another magnetoelectric speed sensor of this utility model.

Detailed Implementation Methods

[0036] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0037] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0038] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0040] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0041] Please see Figure 2 As shown in the figure, the specific embodiment provided by this utility model provides a magnetoelectric speed sensor. The magnetoelectric speed sensor includes a permanent magnet 10 extending along the axial direction, a frame 11 located on the outer periphery of the permanent magnet 10, a coil 12 wrapped around the outer periphery of the frame 11, and a shell 13 covering the coil 12. The coil 12 is located on the outer periphery of the permanent magnet 10 along the axial direction of the permanent magnet 10.

[0042] The technical solution provided in this embodiment employs a coil 12 positioned on the outer periphery of the permanent magnet 10 along its axial direction. This allows the permanent magnet 10 to generate a sufficiently strong magnetic field over a considerable distance from the sensor's measuring end face. When the measured tone wheel 14 is slowly disturbed, a sufficiently large magnetomotive force (EMF) is generated within the induction coil 12 inside the sensor, resulting in a significant increase in the peak output EMF of the magnetoelectric speed sensor. Alternatively, when the measuring gap d2 between the measured tone wheel 14 and the magnetoelectric speed sensor reaches 10 mm or even higher, the magnetoelectric speed sensor can also generate an induced EMF of a certain amplitude, thus meeting the acquisition requirements of the backend acquisition system. Therefore, this magnetoelectric sensor ensures an effective output amplitude under low-speed conditions for the tone wheel 14, while also ensuring that the effective output of the sensor meets the acquisition requirements under large measuring gap d2 conditions. Furthermore, the measuring gap d2 refers to the distance between the end of the permanent magnet 10 adjacent to the tone wheel 14 and the tone wheel 14 along its axial direction. Furthermore, the magnetoelectric speed sensor provided in this embodiment has a simpler and more compact structure and lower cost.

[0043] Specifically, the magnetoelectric speed sensor is used to measure the rotational speed of the tone wheel 14, which is mounted on the shaft being measured.

[0044] Furthermore, coils 12 extend from both ends of the permanent magnet 10 along its axial direction.

[0045] Along the axial direction of the permanent magnet 10, one end of the permanent magnet 10 extends out of the outer shell 13. Specifically, the outer shell 13 extends out of the end of the permanent magnet 10 facing the tone wheel 14. This arrangement allows the permanent magnet 10 to generate a stronger magnetic field over a greater range from its end face extending out of the outer shell 13, making it more sensitive to the detection of slow rotation of the tone wheel 14.

[0046] Along the axial direction of the permanent magnet 10, the other end of the permanent magnet 10 is flush with the end of the frame 11.

[0047] Furthermore, the outer circumference of the permanent magnet 10 is set to be uniform throughout the entire axial direction. This makes the structure of the permanent magnet 10 simpler and the manufacturing cost lower.

[0048] In this embodiment, the permanent magnet 10 that meets the requirements is produced directly by machining or precision casting. Specifically, the material of the permanent magnet 10 is neodymium iron boron. Of course, the material of the permanent magnet 10 can also be samarium cobalt or other materials.

[0049] See further Figure 3When the measurement gap d2 is too large, the measured tone wheel 14 can be modified to ensure that the induced voltage inside the magnetoelectric speed sensor meets the requirements of the backend acquisition. Specifically, a strong magnet 15 is installed on the tone wheel 14, and the polarity of the exposed magnetic pole of the strong magnet 15 is opposite to that of the magnetic pole of the permanent magnet 10 facing the end of the tone wheel 14.

[0050] In this specific embodiment, the strong magnet 15 is embedded in the tone wheel 14. Of course, other fastening methods can also be used to fix it to the tone wheel 14.

[0051] A strong magnet 15 is disposed on the teeth of the tone wheel 14. Furthermore, a strong magnet 15 is disposed on each tooth of the tone wheel 14.

[0052] The above is only one specific embodiment of the present utility model. Any improvements made based on the concept of the present utility model shall be considered within the protection scope of the present utility model.

Claims

1. A magnetoelectric speed sensor, characterized in that, The magnetoelectric speed sensor includes a permanent magnet extending along the axial direction, a frame located on the outer periphery of the permanent magnet, a coil wound around the outer periphery of the frame, and a shell covering the coil. The coil is located on the outer periphery of the permanent magnet along the axial direction of the permanent magnet.

2. The magnetoelectric speed sensor according to claim 1, characterized in that, The coil extends from both ends of the permanent magnet along its axial direction.

3. The magnetoelectric speed sensor according to claim 1, characterized in that, Along the axial direction of the permanent magnet, one end of the permanent magnet extends out of the outer shell.

4. The magnetoelectric speed sensor according to claim 3, characterized in that, Along the axial direction of the permanent magnet, the other end of the permanent magnet is flush with the end of the skeleton.

5. The magnetoelectric speed sensor according to claim 1, characterized in that, The outer circumference of the permanent magnet is set to be consistent throughout the entire axial direction.

6. The magnetoelectric speed sensor according to claim 1, characterized in that, The permanent magnet is made of neodymium iron boron.

7. The magnetoelectric speed sensor according to claim 1, characterized in that, The permanent magnet is made of samarium cobalt.

8. The magnetoelectric speed sensor according to claim 1, characterized in that, The magnetoelectric speed sensor is used to measure the rotational speed of the tone wheel. The tone wheel is equipped with a strong magnet, and the polarity of the exposed magnetic pole of the strong magnet is opposite to that of the magnetic pole of the permanent magnet facing the end of the tone wheel.

9. The magnetoelectric speed sensor according to claim 8, characterized in that, The strong magnet is disposed on the teeth of the tone wheel.

10. The magnetoelectric speed sensor according to claim 9, characterized in that, Each tooth of the sound wheel is equipped with a strong magnet.

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