Direct Warping Machine
A-ZEN
direct warping machine is a new-developed machine with advanced function. A brand
new closed circuit tension technology, known as PID technology, is used on
direct warping machine AZ118L type, and because of that, yarn tension stability
and accuracy are both assured. Meanwhile, the computerized real-time monitoring
system can detect beams` diameters in a accurate way.
Technical Data:
Warp Line Speed: 100-1,000m/min;
Beam Size: Φ21"*21",
Φ30"*21", Φ40"21";
Control
Way: Computerized real-time control;
Tension
Roller: Real-time PID adjusts yarn tension in closed loop control;
Beam
Up-and-down, Clamping and Brake: Pneumatically Operated;
Main
Motor: 7.5KW AC-frequency controlled with constant linear speed and closed
circuit;
Brake
Torque: 1600NM;
Air
Connection: 6 Bar;
Copy
Precision: Beams` perimeters are recorded;
Maximum
Counting Range: 99999 meters/circles.
Direct Warping Machine,Copy Function Warping Machine,Beam Waping Machine,Yarn Warping machine CHANGZHOU A-ZEN TEXTILE TECHNOLOGY CO.,LTD , https://www.barmachinery.com
Introduction to HilbertHuang Transform [2] The HilbertHuang transform consists of two parts, the empirical mode decomposition and the HilbertHuang transform. The purpose of the EMD method EMD method is to obtain a series of intrinsic mode functions that characterize the time scale of the signal feature by decomposing the nonlinear, non-stationary signal, so that each IMF is a single component amplitude or frequency modulated signal.
The energy spectrum is analyzed from the entire process of the HilbertHuang transform. The frequency and amplitude of each IMF component are a function of time, so H(,t) describes the distribution of the amplitude of the signal over time and frequency. If x2(t) is considered to be the energy density of the signal, then H2(,t) also has the physical meaning of energy density, and H2(,t) is called the Hilbert energy spectrum, which is the time-frequency representation of the signal energy. Ignoring the residuals, the energy of the signal after the HilbertHuang transform should be conserved.
HHT-based gear crack fault diagnosis When the gear has fatigue crack failure, when the gear meshes, the amplitude and phase of the vibration signal change, resulting in amplitude and phase modulation. The vibration signal of the faulty gear is often expressed as the modulation of the frequency of the swivel to the meshing frequency and its multiplication. On the spectrogram, two equally spaced sidebands are formed with the meshing frequency as the center. Therefore, the gear fault diagnosis is essentially the identification of the sideband. When there is a local failure of the gear, the faulty tooth generates a larger dynamic load than the other teeth when engaged, and affects the adjacent teeth. As the degree of failure increases, the dynamic load increases and the vibration increases, and the vibration energy changes greatly. The HilbertHuang transform energy spectrum is the time-frequency representation of the signal energy. From the HilbertHuang transform energy spectrum, the energy distribution of the gear vibration signal can be analyzed, and the fault characteristics can be extracted.
The sampling bandwidth is span=6.4kHz, the sampling frequency is 16384Hz, the sampling point is 2048, the motor speed is 1473r/min, the gearbox input shaft gear tooth number z1=28, the output shaft gear tooth number is z2=36, so the input shaft rotation frequency Fr1=24.55Hz, the output shaft rotation frequency is fr2=19.11Hz, and its meshing frequency is fm=688Hz.
The time domain waveform of the vibration signal of the gearbox case when the gearbox output shaft gear single tooth root crack is its power spectrum. Only the double frequency of the meshing frequency can be found from the power spectrum, but there is no sideband information, so it is difficult to judge the location where the fault occurs.
As a result of the empirical mode decomposition of the gear tooth root crack vibration signal, there are 10 IMF components, where c1c9 is the respective intrinsic mode function and c10 is the residual amount; it is the marginal spectrum of each IMF component. It can be seen that the center frequency of the marginal spectrum of each IMF component gradually decreases, which is consistent with the characteristics of EMD decomposition. It can be seen from the above that c1c4 is the high-frequency component of the gear tooth root crack failure and the gear meshing force excitation, and the frequency of c5c9 is low. The frequency range of the middle margin spectrum h1 is 1000 Hz 8000 Hz, and the frequency range of h2 is 600 Hz 4000 Hz, so it can be concluded that the c1 and c2 components are high frequency noise interference. The center frequency of h3 is 1376 Hz, which is the double frequency of the gear meshing frequency. H4c7 gear tooth root crack failure time domain waveform gear tooth root crack vibration signal The self-power spectrum center frequency is 480Hz580Hz, corresponding to the high frequency multiplication of the gearbox output shaft rotation frequency. The center frequency of h9 is 19.11Hz, which is the rotation frequency of the output shaft of the gearbox. The center frequency of the marginal spectrum h8 is 38.22Hz, which is the double frequency of the output shaft rotation frequency of the gearbox. It can be seen that the amplitudes of h8 and h9 are significantly larger than the amplitudes of other frequency components. Therefore, it can be concluded that the gear root crack failure occurs on the output shaft gear, and the natural mode function c9 component corresponds to the vibration mode of the gear root crack failure. Therefore, through the time domain and frequency domain analysis of EMD, it is known that c9 is the vibration signal of the fault characteristic of the output shaft gear root crack. An enlarged view of the marginal spectrum h9 of the intrinsic modal function c9.
It is obvious that the amplitude of the swing frequency of the output shaft is much larger than other frequency components, and the amplitude of the meshing frequency is also larger. And characterizing the characteristic frequency of the gear tooth root crack fault from the frequency domain. For the instantaneous energy calculated by the vibration signal of the tooth root crack, the periodic impact characteristic can be clearly seen. The frequency is exactly the rotation frequency of the axis where the fault gear is located 1/0.0523=19.11Hz. The gear is characterized from the time domain. The time and characteristic period of the root crack failure.
Conclusion A new method for gear fault diagnosis based on HilbertHuang transform is introduced. The EMD method can decompose complex nonlinear and non-stationary signals into a sum of finite empirical modal functions according to the local time characteristic scale of the signal, which is highly efficient. The analysis results of the test results of the tooth root crack of the gearbox gear indicate that: 1) Based on the time domain analysis of empirical mode decomposition, a series of single-component modal functions can be obtained, and each IMF can be amplitude or frequency modulated. The single component signal can thus obtain information such as the amplitude, frequency and the like of each intrinsic mode function. 2) Based on the HilbertHuang transform, the frequency domain analysis of the marginal spectrum of each IMF component can obtain the frequency composition of the gear crack fault vibration signal and the dynamic variation of the amplitude with frequency. 3) Based on the time domain analysis of the instantaneous energy spectrum of HilbertHuang transform, the time of occurrence of the gear crack fault vibration signal and the period of fault occurrence can be obtained, so that the position of the gear crack fault can be effectively identified.
The latest control integration in the practice of gear breakage and cracking