CN106441381B - Magnetoelectric rotating parameter measuring device - Google Patents

Abstract

The invention relates to a magnetoelectric rotation parameter measuring device, which includes a coaxially arranged stator and a rotor, and the rotor also includes a multi-pole magnetic ring fixed relative to the rotating shaft and coaxial with the rotating shaft in addition to the rotating shaft. The multi-pole magnetic ring generates a periodically changing magnetic field around it during rotation; the stator includes a magnetic circuit and a magnetoelectric transducer, and the magnetic circuit gathers the periodically changing magnetic field generated by the multi-pole magnetic ring and converts it It is transmitted to the magnetoelectric transducer, and the magnetoelectric transducer forms an electric signal consistent with the change of the magnetic field intensity by inductively changing the magnetic field. The scheme has simple structure and high sensitivity, and can solve the problems of high cost and inadaptability to harsh environments of existing sensors.

Description

A magnetoelectric rotation parameter measuring device

technical field

The invention relates to the measurement technology of rotation parameters, in particular to a magnetoelectric rotation parameter measurement device.

Background technique

Rotation is a basic form of mechanical motion. It is widely used in various applications closely related to national security and national production construction. Parameters such as speed and position during rotation are closely related to various safe and efficient normal operations. In order to monitor changes in parameters such as speed and position in real time, related sensors are widely used. Currently widely used rotation parameter sensors include gratings, inductive synchros, and magnetic gratings. The principles of these sensors are based on space precision scribing technology. use.

Contents of the invention

The object of the present invention is to provide a magnetoelectric rotation parameter measuring device, which has a simple structure and high sensitivity, and can solve the problems of high cost and unadaptability to harsh environments of existing sensors.

Technical scheme of the present invention is as follows:

A magnetoelectric rotation parameter measuring device, which includes a coaxially arranged stator and a rotor, the rotor also includes a multi-pole magnetic ring fixed relative to the rotating shaft and coaxial with the rotating shaft in addition to the rotating shaft, the multi-pole The magnetic ring generates a periodically changing magnetic field around it during rotation; the stator includes a magnetic circuit and a magnetoelectric transducer, and the magnetic circuit gathers the periodically changing magnetic field generated by the multi-pole magnetic ring and transmits it to the The magnetoelectric transducer is described, and the magnetoelectric transducer forms an electric signal consistent with the change of the magnetic field intensity by inductively changing the magnetic field.

Further, the magnetic circuit includes a choke ring and a plurality of magnetic field converging blocks, the number of pole pairs of the multi-pole magnetic ring is consistent with the logarithm of the magnetic field converging blocks, and there is a gap between the choke ring and each magnetic field converging block. A magnetoelectric transducer is installed; the choke ring forms a closed magnetic circuit with the magnetoelectric transducer, the magnetic field converging block and the multi-pole magnetic ring by confining the magnetic field inside it.

Further, the magnetic field converging block is distributed around the outer side of the multi-pole magnetic ring, and the width of the magnetic field converging block can be adjusted according to the output requirements of the magnetoelectric transducer.

Further, the magnetoelectric transducer includes a magnetostrictive layer and a piezoelectric layer, the length direction of which is in the radial direction of the stator.

Further, the magnetic field converging block and the choke ring are respectively provided with U-shaped grooves, one end of the magnetoelectric transducer is installed in the U-shaped groove of the magnetic field converging block, and the other end of the magnetoelectric transducer is installed in the choke In the U-shaped groove of the magnetic ring, the U-shaped groove is used to apply prestress to the magnetoelectric transducer to improve the performance of the output signal of the magnetoelectric transducer.

Further, the number of pole pairs of the multi-pole magnetic ring is at least two.

Further, it also includes a housing fixed relative to the stator, the stator and the rotor are encapsulated in the housing, and the rotating shaft is supported and connected in the housing through bearings.

In the present invention, the multi-pole magnetic ring rotates with the rotating shaft to generate a periodically changing magnetic field. The magnetic field is transmitted through the magnetic circuit and sensed by the magnetoelectric transducer. Changes with changes in the magnetic field. The change of the magnetic field corresponds to the spatial position of the rotor relative to the stator, that is, the angle of rotation. Therefore, the phase of the electrical signal has a one-to-one correspondence with the relative position of the stator and the rotor, and the frequency of the electrical signal has a relationship with the rotational speed of the rotor. One-to-one correspondence. The measurement of the rotation position can be realized by detecting the phase of the electric signal, and the measurement of the rotation speed can be realized by detecting the frequency of the electric signal. This device avoids the use of inductive elements such as magnetic grids and Hall elements in the prior art, and uses magnetoelectric transducers to induce magnetic fields, and realizes the measurement of rotation parameters through the charge changes output by the magnetoelectric transducers. Lower, less restricted by environmental factors, able to adapt to harsh environments.

This scheme also acts on the magnetic field through the yoke magnetic ring and the magnetic field converging block, and the multi-pole magnetic ring, the magnetic field converging block, the yoke magnetic ring and the magnetoelectric transducer form a closed magnetic circuit, so that the magnetic field is prevented from dispersing in the magnetic circuit; Concentrate into the magnetoelectric transducer, increase the magnetic field intensity induced by the magnetoelectric transducer, thereby improving the electrical signal quality of the magnetoelectric transducer. Also through the specific arrangement of the magnetic field converging block, the rotor rotates one circle, and the electrical signal derived from the magnetoelectric transducer passes through an integer number of cycles, so that the phase of the electrical signal derived from each magnetoelectric converter is consistent, so that each electrical signal can be The signals are added directly to increase the output signal and improve the measurement sensitivity of the device.

The magnetoelectric transducer is composed of a magnetostrictive layer and a piezoelectric layer. Under the action of the change of the external magnetic field, the magnetostrictive layer generates stress or strain, and this mechanical motion is transmitted to the piezoelectric layer. Charges are accumulated on the upper and lower surfaces of the electrical layer, and electrical signals are formed when the charges are drawn out. The amplitude of the electrical signal is related to the magnitude of the magnetic field. The length direction of the magnetoelectric transducer is set in the radial direction of the stator, the induced magnetic field changes significantly, and the stress or strain generated by the magnetostrictive layer is also relatively large, so that the piezoelectric layer derives a large amount of charge, and the generated electrical signal Obviously, it is beneficial for measurement and analysis.

In addition, the U-shaped groove of the magnetic field converging block and the yoke magnetic ring not only plays the role of fixing the magnetoelectric transducer, but also can apply a certain prestress to the magnetostrictive layer and the piezoelectric layer, thereby improving the output performance of the electrical signal . The casing fixes and encapsulates the rotor and stator, protecting the rotor and stator from interference during operation, and the bearing controls the movement of the shaft in the axial and radial directions to ensure stable and effective electrical signals derived.

This solution is a rotation parameter measuring device based on the multi-pole magnetic ring energy conversion structure design. It has the advantages of small size, high sensitivity, convenient processing and production, and resistance to harsh environments. It has significant economic and practical value and broad application prospects.

Description of drawings

Fig. 1 is a structural exploded diagram of the present invention;

Fig. 2 is the structural representation of magnetic field converging block and yoke magnetic ring of the present invention;

Fig. 3 is the structural representation of the stator of the present invention;

Fig. 4 is the structural representation of an embodiment of the magnetoelectric transducer of the present invention;

Fig. 5 is the schematic diagram of magnetoelectric transducer of the present invention when the magnetic field is the strongest;

Fig. 6 is a schematic diagram of the magnetoelectric transducer of the present invention when the magnetic field is the weakest.

Detailed ways

The invention converts the change of the spatial magnetic field generated by the rotation of the multi-pole magnetic ring into the change of the corresponding electric signal through the magnetoelectric transducer, thereby realizing the measurement of the rotation parameter. The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

A magnetoelectric rotation parameter measuring device, as shown in Figure 1, it includes a stator 2 and a rotor 1 coaxially arranged, during operation, the stator 2 does not move, the rotor 1 rotates, and the rotor 1 includes a rotating shaft 12 It includes a multi-pole magnetic ring 11 fixed relative to the rotating shaft 12 and coaxial with the rotating shaft 12 , and the multi-pole magnetic ring 11 generates a periodically changing magnetic field around the rotating process. The stator 2 includes a magnetic circuit and a magnetoelectric transducer 23, the magnetic circuit gathers the periodically changing magnetic field generated by the multi-pole magnetic ring 11 and transmits it to the magnetoelectric transducer 23, the magnetoelectric The transducer 23 forms an electric signal consistent with the change of the magnetic field intensity by inducing the changing magnetic field.

The multi-pole magnetic ring 11 rotates with the rotating shaft 12 to generate a periodically changing magnetic field. The magnetic field is sensed by the magnetoelectric transducer 23 through the magnetic circuit. When the magnetoelectric transducer 23 senses a change in the magnetic field, an electrical signal is derived. Changes with changes in the magnetic field. The change of the magnetic field corresponds to the spatial position of the rotor 1 relative to the stator 2, that is, the angle of rotation. Therefore, the phase of the electrical signal has a one-to-one correspondence with the relative position of the stator and the rotor 1, and the frequency of the electrical signal corresponds to the rotor. The rotational speed of 1 has a one-to-one correspondence. The measurement of the rotation position can be realized by detecting the phase of the electric signal, and the measurement of the rotation speed can be realized by detecting the frequency of the electric signal.

The magnetic circuit is formed by using a yoke magnetic ring 21 and a plurality of magnetic field converging blocks 22. As shown in Figures 2 and 3, the number of pole pairs of the multi-pole magnetic ring 11 is consistent with the logarithm of the magnetic field converging blocks 22. A magnetoelectric transducer 23 is installed between each magnetic field converging block 22 , so that the magnetoelectric transducer 23 is at the position with the strongest magnetic field between the magnetic field converging block 22 and the yoke magnetic ring 21 . The choke ring forms a closed magnetic circuit with the magnetoelectric transducer 23 , the magnetic field converging block 22 and the multi-pole magnetic ring 11 by confining the magnetic field inside it.

The multi-pole magnetic ring 11 adopts a magnetic ring with radial magnetic poles, and the number of sub-magnetic fields with the same shape is related to the number of pole pairs n. The magnetic field converging block 22 is in the shape of an arc strip, which is distributed around the outer side of the multi-pole magnetic ring 11 , and the width of the magnetic field converging block 22 can be adjusted according to the output requirements of the magnetoelectric transducer 23 . When the rotor 1 rotates through an angle of 2π/n relative to the stator 2, the signal derived by the magnetoelectric transducer 23 passes through exactly one cycle, and the phase and spatial displacement of the signal have a one-to-one correspondence, and the frequency and the rotational speed of the signal have a certain One-to-one correspondence. The phases of the signals derived from each magnetoelectric converter are consistent, so that the various electrical signals can be directly added and processed during signal processing.

In the embodiment, a PMP type magnetoelectric transducer 23 can be used, as shown in FIG. 4 , consisting of a middle magnetostrictive layer 231 and upper and lower piezoelectric layers 232 , and its length direction is in the radial direction of the stator 2 . Magnetoelectric transducer 23 is under the effect of external magnetic field, and magnetostrictive layer 231 produces stress or strain, and this mechanical motion is passed to piezoelectric layer 232 by the bonding layer of bonding magnetostrictive layer 231 and piezoelectric layer 232, because Piezoelectric effect, accumulating charges on the upper and lower surfaces of the piezoelectric layer 232, drawing out the charges to form an electrical signal, the magnitude of the electrical signal is related to the magnitude of the external magnetic field. The magnetostrictive layer 231 senses the magnetic field in the environment. Because the strength of the magnetic field is different, the stretching size of the stretching layer is different. This difference in stretching size will produce different stresses or strains on the piezoelectric layer 232, so that the piezoelectric layer The amplitudes of the electrical signals generated on the 232 are also different.

The PMP type structure that this example adopts should not be used as the restriction or limitation of the technical scheme of the present invention, it also can be that piezoelectric layer 232 is in the middle, and both sides are the MPM type three-layer structure of magnetostrictive layer 231, also can be MP type Two-layer structure or other multi-layer structure forms.

Described magnetic field converging block 22, yoke magnetic ring 21 are provided with U-shaped groove 24 respectively, and one end of described magnetoelectric transducer 23 is installed in the U-shaped groove 24 of magnetic field converging block 22, and the other end of magnetoelectric transducer 23 One end is installed in the U-shaped groove 24 of the yoke magnetic ring 21. The U-shaped groove 24 and the magnetoelectric transducer 23 form a tooth-shaped magnetic circuit. The transducer 23 enters the yoke magnetic ring 21 , flows from the yoke magnetic ring 21 to the adjacent magnetoelectric transducer 23 , the magnetic field converging block 22 and returns to the multi-pole magnetic ring 11 . The tooth-shaped magnetic circuit can reduce magnetic flux leakage so that the magnetic field can pass through the magnetoelectric transducer 23 to the greatest extent. The U-shaped groove 24 can also apply prestress to the magnetoelectric transducer 23 to improve the performance of the output signal of the magnetoelectric transducer 23 .

Taking the multi-pole magnetic ring 11 with two pairs of poles in Fig. 5 and 6 as an example, when the stator and rotor 1 of the measuring device are in the position shown in Fig. 5, the multi-pole magnetic ring 11, the magnetic field converging block 22, The magnetic field formed in the transducer 23 and the yoke magnetic ring 21 is shown in Figure 5. At this moment, the magnetic field generated on the magnetoelectric transducer 23 is the strongest, and the magnetic field derived from the piezoelectric layer 232 of the magnetoelectric transducer 23 is The greater the voltage, the more the multi-pole magnetic ring 11 rotates clockwise, the magnetic field converged by the magnetic field converging block 22 will gradually weaken. The magnetic field felt by the magnetostrictive layer 231 is also weaker, thereby the voltage derived on the piezoelectric layer 232 is also smaller, and the multi-pole magnetic ring 11 continues to rotate, and the magnetic field felt by the magnetostrictive layer 231 will gradually become stronger. The voltage derived from the piezoelectric layer 232 will also increase accordingly, and so on. Because the magnetostrictive layer 231 only senses the magnitude of the magnetic field, so when the multi-pole magnetic ring 11 rotates one opposite pole, the magnetic field strength passing through the magnetostrictive layer 231 has gone through two cycles, that is, when the magnetic ring rotates 360 degrees, The intensity of the magnetic field passing through the magnetostrictive layer 231 will produce four-period changes as the position changes, and the voltage derived on the piezoelectric layer 232 is a corresponding four-period signal. By detecting the phase value of the voltage signal derived on the conductive layer of the magnetoelectric transducer 23, it is possible to know how many angles the multipole magnetic ring 11 and the rotor 1 have turned with respect to the stator 2, thereby realizing the measurement of the rotation angle, and deriving through detection The frequency of the voltage signal can be used to know the rotation speed, so that the simultaneous measurement of the rotation angle and the rotation speed can be realized.

In practical application of this device, the rotor 1 and the stator 2 will be packaged with a casing. The casings 5 and 6 in Fig. 1 are fixed relative to the stator 2, and the rotor 1 is installed in the casings 5 and 6. Body 5, 6 plays the role of fixing and packaging. One end of the rotating shaft 12 is connected to the bearing 3, and the bearing 4 on the right is connected with the stator 2. The bearings 3 and 4 play a role in supporting the rotating shaft 12, so that the rotating shaft 12 can rotate, and control the rotation of the rotating shaft 12 in the axial and radial directions. of the mobile.

Claims (5)

1. The utility model provides a magnetoelectric rotating parameter measuring device, includes the stator and the rotor of coaxial setting, its characterized in that: the rotor comprises a rotating shaft and a multi-pole magnetic ring which is fixed relative to the rotating shaft and is coaxial with the rotating shaft, and the multi-pole magnetic ring generates a periodically-changing magnetic field around in the rotating process; the stator comprises a magnetic circuit and a magnetoelectric transducer, the magnetic circuit converges a periodically-changed magnetic field generated by the multipole magnetic ring and transmits the periodically-changed magnetic field to the magnetoelectric transducer, and the magnetoelectric transducer forms an electric signal consistent with the change of the magnetic field intensity by inducing the changed magnetic field;

the magnetic circuit comprises a yoke magnetic ring and a plurality of magnetic field convergence blocks, the magnetic field convergence blocks are distributed on the outer side of the multi-pole magnetic ring in a surrounding manner, and a magnetoelectric transducer is arranged between the yoke magnetic ring and each magnetic field convergence block; the yoke magnetic ring forms a closed magnetic circuit together with the magnetoelectric transducer, the magnetic field convergence block and the multi-pole magnetic ring by confining a magnetic field inside the yoke magnetic ring;

The magnetic field convergence block and the yoke magnetic ring are respectively provided with a U-shaped groove, one end of the magnetoelectric transducer is arranged in the U-shaped groove of the magnetic field convergence block, the other end of the magnetoelectric transducer is arranged in the U-shaped groove of the yoke magnetic ring, and the U-shaped groove is used for applying prestress to the magnetoelectric transducer so as to improve the performance of the output signal of the magnetoelectric transducer;

the magnetoelectric transducer includes a magnetostrictive layer and a piezoelectric layer, and the length direction thereof is in the radial direction of the stator.

2. The magnetoelectric rotating parameter measuring device according to claim 1, wherein: the number of pole pairs of the multi-pole magnetic ring is consistent with the number of pairs of the magnetic field convergence blocks.

3. The magnetoelectric rotating parameter measuring device according to claim 2, wherein: the width of the magnetic field convergence block can be adjusted according to the output requirement of the magnetoelectric transducer.

4. the magnetoelectric rotating parameter measuring device according to claim 1, wherein: the number of the magnetic pole pairs of the multi-pole magnetic ring is at least two.

5. An magnetoelectric rotating parameter measuring apparatus according to any one of claims 1 to 4, wherein: the stator and the rotor are packaged in the shell, and the rotating shaft is connected in the shell through a bearing support.