A Diagnosis Method for Planetary Gear with Local Defects Using Selected Features

2021 ◽  
pp. 1103-1114
Author(s):  
ZhanChi Liu ◽  
HeQing Sun ◽  
HongHua Huang
Keyword(s):  
Planetary Gear ◽  
Diagnosis Method ◽  
Local Defects

Helicopter main reduction planetary gear fault diagnosis method based on SVDD

2020 ◽  
Vol 64 (1-4) ◽  
pp. 137-145
Author(s):  
Yubin Xia ◽  
Dakai Liang ◽  
Guo Zheng ◽  
Jingling Wang ◽  
Jie Zeng
Keyword(s):  
Fault Diagnosis ◽  
Planetary Gear ◽  
Gaussian Kernel ◽  
Support Vector ◽  
Support Vector Data Description ◽  
Vector Data ◽  
Energy Characteristics ◽  
Gear Fault ◽  
Channel Information ◽  
Diagnosis Method

Aiming at the irregularity of the fault characteristics of the helicopter main reducer planetary gear, a fault diagnosis method based on support vector data description (SVDD) is proposed. The working condition of the helicopter is complex and changeable, and the fault characteristics of the planetary gear also show irregularity with the change of working conditions. It is impossible to diagnose the fault by the regularity of a single fault feature; so a method of SVDD based on Gaussian kernel function is used. By connecting the energy characteristics and fault characteristics of the helicopter main reducer running state signal and performing vector quantization, the planetary gear of the helicopter main reducer is characterized, and simultaneously couple the multi-channel information, which can accurately characterize the operational state of the planetary gear’s state.

scholarly journals Nonlinear Dynamic Characteristics of Fixed-Axis Gear Wear in Multistage Gear Transmission Systems

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Xin Wang
Keyword(s):  
Planetary Gear ◽  
Transition Process ◽  
Transmission System ◽  
Gear Transmission ◽  
Gear Teeth ◽  
Gear Transmission System ◽  
Diagnosis Method ◽  
Fixed Axis ◽  
Spectrum Characteristics ◽  
The Stability

With the increasing service life of a gear transmission system, the gear teeth become constantly worn and the gear clearance increases. The increase in the clearance will produce a series of nonlinear changes that change the stability of the system and can even cause the loss of stability. In this paper, dimensionless dynamic equations of a multistage gear transmission system that contains a two-stage fixed-axis gear and a one-stage planetary gear were derived. The wear fault was simulated by changes in the gear clearance. System bifurcation diagrams with an increase in the clearance were studied. The motion state and transition process of the multistage gear transmission system with a wear fault were studied using the Poincaré section. The change in the spectrum characteristics with an increase in the clearance was analyzed. The frequency spectrum characteristics of the wear fault were discovered. The vibration mechanism and a fault wear diagnosis method in a multistage gear transmission system were obtained.

scholarly journals A Non-Contact Fault Diagnosis Method for Bearings and Gears Based on Generalized Matrix Norm Sparse Filtering

Entropy ◽  
2021 ◽  
Vol 23 (8) ◽  
pp. 1075
Author(s):  
Huaiqian Bao ◽  
Zhaoting Shi ◽  
Jinrui Wang ◽  
Zongzhen Zhang ◽  
Guowei Zhang
Keyword(s):  
Fault Diagnosis ◽  
Engineering Application ◽  
Planetary Gear ◽  
Acoustic Signals ◽  
Matrix Norm ◽  
Mechanical Equipment ◽  
Data Set ◽  
Sparse Filtering ◽  
Generalized Matrix ◽  
Diagnosis Method

Fault diagnosis of mechanical equipment is mainly based on the contact measurement and analysis of vibration signals. In some special working conditions, the non-contact fault diagnosis method represented by the measurement of acoustic signals can make up for the lack of contact testing. However, its engineering application value is greatly restricted due to the low signal-to-noise ratio (SNR) of the acoustic signal. To solve this deficiency, a novel fault diagnosis method based on the generalized matrix norm sparse filtering (GMNSF) is proposed in this paper. Specially, the generalized matrix norm is introduced into the sparse filtering to seek the optimal sparse feature distribution to overcome the defect of low SNR of acoustic signals. Firstly, the collected acoustic signals are randomly overlapped to form the sample fragment data set. Then, three constraints are imposed on the multi-period data set by the GMNSF model to extract the sparse features in the sample. Finally, softmax is used to as a classifier to categorize different fault types. The diagnostic performance of the proposed method is verified by the bearing and planetary gear datasets. Results show that the GMNSF model has good feature extraction ability performance and anti-noise ability than other traditional methods.

Diagnosis Method of Aging Degradation for Insulating Paper using Small Amount of Cellulose Fibers

2019 ◽  
Vol 139 (2) ◽  
pp. 130-135
Author(s):  
Masanobu Yoshida ◽  
Yoshinori Konishi ◽  
Masamichi Kato
Keyword(s):  
Cellulose Fibers ◽  
Insulating Paper ◽  
Diagnosis Method

Our Surgical Strategy for Thoracic Outlet Syndrome

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Yasuhiro Nakajima
Keyword(s):  
Brachial Plexus ◽  
Thoracic Outlet Syndrome ◽  
Vascular Compression ◽  
Compression Tests ◽  
Provocation Tests ◽  
Diagnosis Method ◽  
Tunnel Syndrome ◽  
Electrophysiological Examination ◽  
Sensory Neural ◽  
Plexus Block

Surgical treatment for thoracic outlet syndrome (TOS) is a very controversial surgery because objective diagnosis, such as image and electrophysiological examination, is very difficult. Clinical provocation tests including brachial plexus compression tests, such as Morley and Roos, and vascular compression tests, such as Wright and Eden ,are not high in specificity and are likely to be positive even in healthy persons and patients with carpal tunnel syndrome. We place emphasis on the laterality of latency and amplitude in the sensory neural action potential (SNAP) of the medial antebrachial cutaneous nerve and ulnar nerve. After enough stretching exercises of scapular stabilizers and brachial plexus block, we always select surgery. In this presentation, I would like to show our diagnosis method and treatment strategy including surgery.

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