Electric low-frequency long-stroke vibration table and working method thereof
By using a servo motor to drive the worm gear and worm reciprocating motion, the hysteresis nonlinearity problem of the electromagnetic vibration table during low-frequency long-stroke output is solved, realizing accurate output of low-frequency mechanical vibration signals and improving vibration calibration accuracy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YICHANG TESTING TECHNIQUE RESEARCH INSTITUTE
- Filing Date
- 2025-12-11
- Publication Date
- 2026-05-01
AI Technical Summary
Existing electromagnetic vibration tables suffer from hysteresis nonlinearity at low frequencies and long strokes, which leads to waveform distortion, affects vibration calibration accuracy, and makes it difficult to achieve low-frequency vibration below 5Hz.
A servo motor drives a worm gear and worm to reciprocate through a reducer, generating mechanical vibration. By increasing the diameter of the worm gear, a long stroke motion is obtained, avoiding the suspension structure. A sine wave generator and a linear power amplifier are used to generate low-frequency signals, and a mechanical gearbox reducer is used to increase the rotational stroke.
It achieves low-frequency mechanical vibration signal output as low as 0.5Hz, avoids the nonlinearity problem of the suspension structure of the electromagnetic vibration table, and improves vibration calibration accuracy and signal-to-noise ratio.
Smart Images
Figure CN121954201A_ABST
Abstract
Description
An electrically powered low-frequency long-stroke vibration table and its working method Technical Field
[0001] This invention relates to the field of motor-driven long-stroke reciprocating motion technology, mainly used for testing vibration sensors under extremely low frequency and long stroke conditions, specifically relating to an electric low-frequency long-stroke vibration table and its working method. Background Technology
[0002] Currently, the low-frequency vibration sensors on the market can theoretically operate at frequencies as low as 0.5Hz. However, due to limitations in testing methods, the low-frequency cutoff frequency of their operating band is difficult to support with actual measurement values and must be supplemented by theoretical derivation.
[0003] The main reason for the above problems is that the vibration table used for vibration sensor testing provides a standard vibration signal to the vibration sensor through reciprocating motion. Currently, electromagnetic vibration tables are commonly used. Their working principle is based on a voice coil motor, which excites the mover (moving coil) to vibrate through the electromagnetic force generated by a permanent magnet. When the mover (moving coil) is working, it is in a suspended state under the action of electromagnetic force, making it difficult to achieve low-frequency vibration below 5Hz. Furthermore, when a long-stroke vibration excitation is required to generate a sufficient signal-to-noise ratio, the nonlinearity of the structural parameters of the electromagnetic vibration table gradually increases as the stroke increases: the air gap magnetic field of the electromagnetic vibration table gradually decays as it moves away from the permanent magnet, and the magnetic induction intensity parameter of the electromagnetic vibration table will exhibit significant nonlinearity, resulting in waveform distortion of the output vibration excitation signal and affecting the vibration calibration accuracy.
[0004] In summary, electromagnetic vibration tables have complex hysteresis nonlinearity problems when outputting at low frequencies and long strokes. Waveform distortion affects the low-frequency output performance of the vibration table. Therefore, current electromagnetic vibration tables typically operate at frequencies above 5 Hz.
[0005] To avoid the limitation of the operating frequency of the moving coil in an electromagnetic vibration table when it is suspended, it is necessary to provide an electric low-frequency long-stroke vibration table and its operating method. Summary of the Invention
[0006] In view of this, the present invention provides an electrically driven low-frequency long-stroke vibration table and its working method to solve the problems existing in the background art. It uses a servo motor to drive the worm gear and worm to reciprocate through a reducer to form mechanical vibration. The worm gear drives the suspension structure to avoid the suspension structure, thus forming an electrically driven vibration table. By increasing the diameter of the worm gear, the long stroke motion of the worm can be obtained, providing low-frequency, long-stroke mechanical vibration signals.
[0007] The technical solution of this invention is as follows: an electric low-frequency long-stroke vibration table, comprising: a signal source, a motor driver, a servo motor, a reducer, a worm gear, and a worm; the signal source, motor driver, servo motor, and reducer are connected in series, the output end of the reducer is connected to the worm gear, and the gear on the worm gear meshes with the teeth on the worm; the signal source generates a single-frequency low-frequency sinusoidal signal, the motor driver amplifies the power of the signal and drives the servo motor, the rotation of the servo motor is proportionally reduced by the reducer, and then drives the worm gear to rotate, the rotation of the worm gear drives the worm to reciprocate; by increasing the diameter of the worm gear, a long-stroke motion of the worm is obtained.
[0008] Preferably, the signal source is a sine wave generator capable of generating a single-frequency sine wave signal as low as 0.5 Hz.
[0009] Preferably, the motor driver employs a linear power amplifier to linearly amplify the voltage and current of the sinusoidal signal generated by the signal source.
[0010] Preferably, the servo motor is a low-speed DC motor with a speed as low as 60 rpm.
[0011] Preferably, the reducer is a mechanical gearbox reducer, which reduces the speed of the servo motor and increases the rotational stroke through a fixed reduction ratio between the gears.
[0012] Preferably, the worm gear and worm are a bidirectional worm gear-worm assembly.
[0013] A method for operating an electrically powered low-frequency long-stroke vibration table, the method using the vibration table as described in any one of claims 1-6, includes: Step 1: Selecting the frequency of the test signal of the vibration sensor under test, generating a single-frequency sine wave signal of that frequency using a signal source, and inputting it into a motor driver; Step 2: The motor driver converts the sine wave signal from the signal source into a high-power drive signal, and uses this to drive a servo motor to rotate; Step 3: The servo motor generates a rotation with the same frequency as the frequency signal source, and after passing through a reducer, its rotation frequency is reduced to 1 / 10 of its original value; Step 4: The output end of the reducer drives the worm gear to rotate, and through gear transmission between the worm gear and the worm, the rotation of the worm gear is converted into the linear reciprocating motion of the worm, simulating the generation of a vibration signal; Step 5: By changing and recording the frequency of the test signal, repeating steps 1 to 4, the vibration frequency of the sensor under test and the response relationship of the vibration signal are obtained.
[0014] Beneficial effects: (1) The vibration table provided by the present invention uses a servo motor to drive the worm wheel and worm to reciprocate, forming mechanical vibration. That is, the gear drive avoids the floating structure of the moving part of the voice coil motor in the electromagnetic vibration table, forming a gear tooth meshing connection. Through the contact connection, an electric vibration table is formed to realize low-frequency mechanical vibration signal. By increasing the diameter of the worm wheel, the long stroke motion of the worm can be obtained.
[0015] (2) The signal source in this invention is a sine wave generator, which can generate a single-frequency sine wave signal as low as 0.5 Hz, which is beneficial for generating low-frequency mechanical vibration signals.
[0016] (3) In this invention, the reducer adopts a mechanical gearbox reducer. By using the fixed reduction ratio between the gears, the low-speed rotation of the servo motor is further reduced, while the rotation stroke is increased. After the worm gear and worm are used to convert the circular motion into linear reciprocating motion, low-frequency, large-stroke vibration is achieved, which is beneficial to obtaining the vibration frequency and vibration signal response relationship of the sensor under test.
[0017] (4) The vibration table working method provided by the present invention uses a signal source to generate a set low-frequency sine signal, and a motor driver amplifies the sine signal and drives a servo motor. The servo motor drives the worm gear and worm to reciprocate, forming mechanical vibration. That is, the gear drive avoids the floating structure of the moving part of the voice coil motor in the electromagnetic vibration table, and forms a gear tooth meshing connection. The low-frequency mechanical vibration signal is realized through the contact connection. Attached Figure Description
[0018] Figure 1 is a schematic diagram of the structure of the vibration table in this invention.
[0019] Figure 2 is a schematic diagram of the worm gear and worm wheel assembly in this invention.
[0020] Among them, 1-signal source, 2-motor driver, 3-servo motor, 4-reducer, 5-worm gear, 6-worm. Detailed Implementation
[0021] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0022] This embodiment provides an electrically driven low-frequency long-stroke vibration table and its working method to solve the problems existing in the background technology. It uses a servo motor to drive the worm gear and worm to reciprocate through a reducer to form mechanical vibration. The worm gear drives the suspension structure to avoid the suspension structure, thus forming an electrically driven vibration table. By increasing the diameter of the worm gear, the long stroke motion of the worm can be obtained, providing low-frequency, long-stroke mechanical vibration signals.
[0023] To achieve low-frequency vibration down to below 0.5Hz, as shown in Figure 1, the vibration table in this embodiment includes: a signal source 1, a motor driver 2, a servo motor 3, a reducer 4, a worm gear 5, and a worm 6. The signal source 1, motor driver 2, servo motor 3, and reducer 4 are connected in series. The output end of the reducer 4 is connected to the worm gear 5. The gear on the worm gear 5 meshes with the teeth on the worm 6, and the rotation of the worm gear 5 drives the worm 6 to perform linear reciprocating motion. The signal source 1 generates a single-frequency low-frequency sinusoidal signal. The motor driver 2 amplifies this signal (mainly through linear amplification of voltage and current). The signal drives the servo motor 3 to rotate. After the rotation of the servo motor 3 is proportionally reduced by the reducer 4, the rotation speed becomes slower, which in turn drives the worm wheel 5 to rotate. The rotation of the worm wheel 5 drives the worm 6 to reciprocate, forming a low-frequency sinusoidal vibration signal. The changes in the rotational speed and phase of the servo motor 3 are consistent with the input sinusoidal signal. Since the linear velocity on the edge circumference of the worm wheel 5 can be converted into the linear velocity of the worm 6, and the signal driving the servo motor 3 is a sinusoidal signal, the velocity distribution of the worm 6 is also sinusoidal. By adjusting and increasing the diameter of the worm wheel 5, a long stroke motion of the worm 6 can be obtained.
[0024] As shown in Figure 2, the gear on the worm wheel 5 meshes with the teeth on the worm 6, so that the rotation of the worm wheel 5 can drive the worm 6 to reciprocate, forming a sinusoidal vibration signal.
[0025] In this embodiment, signal source 1 uses a commonly used sine wave generator, which can generate a single-frequency sine wave signal as low as 0.5Hz.
[0026] In this embodiment, the motor driver 2 uses a commonly used linear power amplifier, which can linearly amplify the voltage and current of the sinusoidal signal generated by the signal source 1.
[0027] In this embodiment, the servo motor 3 is a general-purpose low-speed DC motor with a speed as low as 60 rpm, that is, a rotation cycle of 1 rpm and a rotation frequency of 1 Hz.
[0028] In this embodiment, the reducer 4 adopts a mechanical gearbox reducer. By using a fixed reduction ratio between the gears (in this embodiment, the speed ratio is 10:1, which can reduce the speed to 1 / 10 of the original speed), the speed of the servo motor 3 is reduced and the rotational stroke is increased.
[0029] In this embodiment, the worm gear 5 and the worm 6 are a bidirectional worm gear assembly. The meshing of their gears transforms rotation into reciprocating motion, enabling the worm 6 to simulate and generate vibration signals that meet expectations.
[0030] The vibration table in this invention operates as follows: Step 1: Select the frequency of the test signal of the vibration sensor under test, generate a single-frequency sinusoidal signal (e.g., a 5Hz single-frequency sinusoidal signal) of that frequency using signal source 1, and input it into motor driver 2; Step 2: Motor driver 2 converts the sinusoidal signal from signal source 1 into a high-power drive signal, and uses it to drive servo motor 3 to rotate; Step 3: Servo motor 3 generates a rotation with a frequency of 5Hz. After passing through reducer 4, the rotation frequency of this rotation signal is reduced to 1 / 10 of its original value (0.5Hz); Step 4: The output end of reducer 4 drives worm gear 5 to rotate, and through gear transmission between worm gear 5 and worm 6, the rotation of worm gear 5 is converted into linear reciprocating motion of worm 6, simulating the generation of vibration signal; Step 5: By changing the frequency of the test signal and recording it, repeating steps 1 to 4, the vibration frequency of the sensor under test and the response relationship of the vibration signal can be obtained.
[0031] In this embodiment, since the entire vibration table system controls the rotational speed of the servo motor 3, and thus controls the speed of the linear reciprocating motion between the worm wheel 5 and the worm 6, the vibration table outputs a vibration velocity signal.
[0032] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. An electrically driven low-frequency long-stroke vibration table, characterized in that, include: Signal source, motor driver, servo motor, reducer, worm gear and worm; The signal source, motor driver, servo motor, and reducer are connected in series. The output end of the reducer is connected to the worm gear, and the gear on the worm gear meshes with the teeth on the worm. The signal source generates a single-frequency low-frequency sine wave signal. The motor driver amplifies the power of the signal and drives the servo motor. The rotation of the servo motor is proportionally reduced by the reducer and then drives the worm gear to rotate. The rotation of the worm gear drives the worm to reciprocate. By increasing the diameter of the worm gear, a long stroke motion of the worm can be obtained.
2. The electrically driven low-frequency long-stroke vibration table as described in claim 1, characterized in that, The signal source uses a sine wave generator, which can generate a single-frequency sine wave signal as low as 0.5 Hz.
3. The electrically driven low-frequency long-stroke vibration table as described in claim 1, characterized in that, The motor driver employs a linear power amplifier to linearly amplify the voltage and current of the sinusoidal signal generated by the signal source.
4. The electrically driven low-frequency long-stroke vibration table as described in claim 1, characterized in that, The servo motor is a low-speed DC motor with a speed as low as 60 rpm.
5. The electrically driven low-frequency long-stroke vibration table as described in claim 1, characterized in that, The reducer is a mechanical gearbox reducer, which reduces the speed of the servo motor and increases the rotational stroke through a fixed reduction ratio between the gears.
6. The electrically driven low-frequency long-stroke vibration table as described in claim 1, characterized in that, The worm gear and worm are a bidirectional worm gear-worm assembly.
7. A method for operating an electrically driven low-frequency long-stroke vibration table, characterized in that, The working method uses the vibration table as described in any one of claims 1-6, and includes: Step 1: Selecting the frequency of the test signal of the vibration sensor under test, generating a single-frequency sine wave signal of that frequency using a signal source, and inputting it into the motor driver; Step 2: The motor driver converts the sine wave signal from the signal source into a high-power drive signal, and uses it to drive the servo motor to rotate; Step 3: The servo motor generates a rotation with the same frequency as the frequency signal source, and after passing through a reducer, its rotation frequency is reduced to 1 / 10 of the original value; Step 4: The output end of the reducer drives the worm gear to rotate, and through the gear transmission between the worm gear and the worm, the rotation of the worm gear is converted into the linear reciprocating motion of the worm, simulating the generation of a vibration signal; Step 5: By changing the frequency of the test signal and recording it, repeating steps 1 to 4, the vibration frequency of the sensor under test and the response relationship of the vibration signal are obtained.