Study on the Field Dynamic Balance of Diesel Engine Crankshaft

2013 ◽  
Vol 307 ◽  
pp. 299-303
Author(s):  
Shi Xun Jiang ◽  
Shi Hai Zhang ◽  
Zhi Min Yu
Keyword(s):  
Diesel Engine ◽  
Dynamic Balance ◽  
Least Square Method ◽  
Least Square ◽  
Vibration Monitoring ◽  
Influence Coefficient ◽  
Balance System ◽  
Influence Coefficient Method ◽  
Field Dynamic ◽  
Engine Crankshaft

Abstract：Based on the actual situations of diesel engines, significance of dynamic balance for marine diesel engine crankshaft system is discussed and as well vibration monitoring and field dynamic balance system for diesel engine crankshaft system is constructed. The least square method is applied to fit fundamental frequency vibration signals of crankshaft system and the field dynamic balance strategy is designed on the basis of the influence coefficient method. The feasibility of the dynamic balance system is tested through experiments in the paper.

Research for the Crack Dynamic Monitoring of Marine Diesel Engine

2014 ◽  
Vol 556-562 ◽  
pp. 3107-3111
Author(s):  
Zhi Min Yu ◽  
Shi Hai Zhang ◽  
Shi Xun Jiang
Keyword(s):  
Diesel Engine ◽  
Fatigue Fracture ◽  
Dynamic Balance ◽  
Dynamic Monitoring ◽  
Influence Coefficient ◽  
Marine Diesel Engine ◽  
Balance System ◽  
Marine Diesel ◽  
Field Dynamic ◽  
Engine Crankshaft

crankshaft is one of the most important parts and crankshaft fatigue fracture is a major failure. In order to alert fatigue fracture of crankshaft to prevent accidents, diesel engine crankshaft dynamic monitoring based on the actual situations of diesel engines, significance of dynamic balance for marine diesel engine crankshaft system is discussed and as well vibration monitoring and field dynamic balance system for diesel engine crankshaft system is constructed. The least square method is applied to fit fundamental frequency vibration signals of crankshaft system and the field dynamic balance strategy is designed on the basis of the influence coefficient method. The feasibility of the dynamic balance system is tested through experiments in the paper.

scholarly journals Research on the Field Dynamic Balance Technologies for Large Diesel Engine Crankshaft System

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Shihai Zhang ◽  
Zimiao Zhang
Keyword(s):  
Diesel Engine ◽  
Field Experiments ◽  
Vibration Signal ◽  
Least Square Method ◽  
Least Square ◽  
Influence Coefficient ◽  
Dynamic Balancing ◽  
Field Dynamic ◽  
Engine Crankshaft ◽  
Field Dynamic Balancing

In order to reduce the unbalancing mass and the accompanying unbalancing vibration of diesel engine crankshaft system, the field dynamic balancing method and its key technologies are presented in the paper. In order to separate the unbalancing vibration signal from the total vibration signal of crankshaft system, the fundamental frequency signal fitting principle based on the least square method was introduced firstly, and then wavelet noise reduction method was applied to improve the signal fitting precision of least square method. Based on the unbalancing vibration signal analysis and assessment of crankshaft system, the influence coefficient method was applied to calculate the value and phase of the equivalent unbalancing mass in flywheel. To easily correct the unbalancing condition of crankshaft system, the unbalancing adjustment equipment was designed based on the flywheel structure. The balancing effect of field dynamic balancing system designed for the large diesel engine has been verified by field experiments.

Online measuring and estimating methods for the unbalancing vector of thin-disc workpiece based on the adaptive influence coefficient

2020 ◽  
pp. 107754632094838
Author(s):  
Shihai Zhang ◽  
Zimiao Zhang
Keyword(s):  
Fundamental Frequency ◽  
Kinetic Characteristic ◽  
Least Square Method ◽  
Frequency Component ◽  
Least Square ◽  
Vibration Monitoring ◽  
Influence Coefficient ◽  
Thin Disc ◽  
Rotary Mechanism ◽  
Fundamental Frequency Component

The thin-disc part is the common part of the rotary mechanism. Because of the large rotating radius of the thin-disc part, the huge unbalancing vector may be formed even if the unbalancing mass is small. So, the unbalance of the thin-disc part is the important exciting factor of the rotary mechanism vibration. Based on the structural characteristics of the thin-disc part, the measuring and estimating methods for the unbalancing vector of the thin-disc workpiece are proposed based on the single-face influence coefficient method. The least square method is introduced to fit the fundamental frequency component from the vibration monitoring signal, and the fundamental frequency component is taken as the unbalancing vibration signal of spindle first. The influence coefficient between the trial weight face and vibration monitoring point on the spindle is tested by trial weight experiments second. The unbalancing vibration difference of the spindle, before and after the thin-disc workpiece is clamped, is monitored and used to estimate the unbalancing vector of the thin-disc workpiece based on the linear reversible principle of unbalancing excitation and vibration response. The signal separation accuracy of the least square method for unbalancing vibration has been proved by simulation and experiment methods. Considering that the accuracy of the influence coefficient may be influenced by the change of the spindle system kinetic characteristic parameters, the signal measurement, analysis error, etc., the adaptive method for the influence coefficient is proposed and proved by the experiment method in the article. The research results show that the unbalancing vector of the thin-disc workpiece can be measured and estimated before the workpiece is taken down from the machine tool spindle. The proposed method can be used to measure and estimate the unbalancing vector of the thin-disc workpiece without dynamic balancing machine, and the measuring efficiency and accuracy can be improved; the measuring cost can be reduced.

NCSXRF: A General Geometry Monte Carlo Simulation Code for EDXRF Analysis

1991 ◽  
Vol 35 (B) ◽  
pp. 727-736 ◽  
Author(s):  
T. He ◽  
R. P. Gardner ◽  
K. Verghese
Keyword(s):  
Least Square ◽  
Influence Coefficient ◽  
Standard Samples ◽  
Simulation Code ◽  
X Ray ◽  
Fundamental Parameters ◽  
Edxrf Analysis ◽  
Influence Coefficient Method ◽  
Energy Pulse

EDXRF analysis is conveniently split into two parts: (1) the determination of X-ray intensities and (2) the determination of elemental amounts from X-ray intensities. For the first, most EDXRF analysis has been done by some method of integrating the essentially Gaussian distribution of observed full energy pulse heights. This might be done, for example, by least-square fitting of Gaussian distributions superimposed on a straight line or a quadratic background. Recently more elaborate shapes of the energy peaks also have been considered (Kennedy, 1990). After the X-ray intensities have been determined, interelement effects between the analyte element and other elements must be corrected for in order to obtain the elemental amounts from X-ray intensities. This correction can be done either by an empirical correction procedure as in the influence coefficient method which requires measurements on a number of standard samples to determine the required coefficients, or by theoretical calculation as in the fundamental parameters method which does not require standard samples.

Study on an Intelligent Teaching Dynamic Balance Technology

2013 ◽  
Vol 483 ◽  
pp. 174-176 ◽  
Author(s):  
Shu Ping Cai ◽  
Ting Zhao
Keyword(s):  
Dynamic Balance ◽  
Far Infrared ◽  
Test System ◽  
Influence Coefficient ◽  
Dynamic Balancing ◽  
Influence Coefficient Method ◽  
Sensitive Sensor ◽  
Phase Sensor ◽  
Electric Measuring ◽  
Coefficient Method

Abstract:.:Intelligent teaching Dynamic balancing is a new kind of dynamic balancing test system with various functions of teaching need. It integrates the hard bearing method using A, B, C size solution with soft bearing method using the influence coefficient method solution. The system is mainly composed of machine frame, intelligent electric measuring box, high sensitive sensor and far infrared phase sensor. It has the advantages of small volume, simple operation, security with low speed，reliable and convenient operation for students. It can deepen students' understanding of balancing knowledge, which has won the national utility model patent.

Adaptively robust filtering algorithm for maritime celestial navigation

2021 ◽  
pp. 1-13
Author(s):  
Chong-hui Li ◽  
Zhang-lei Chen ◽  
Xin-jiang Liu ◽  
Bin Chen ◽  
Yong Zheng ◽  
...  
Keyword(s):  
Dynamic Balance ◽  
Least Square Method ◽  
Least Square ◽  
Astronomical Observation ◽  
Status Change ◽  
Navigation Algorithm ◽  
Celestial Navigation ◽  
Important Means ◽  
Vessel Motion ◽  
The Impact

Abstract Celestial navigation is an important means of maritime navigation; it can automatically achieve inertially referenced positioning and orientation after a long period of development. However, the impact of different accuracy of observations and the influence of nonstationary states, such as ship speed change and steering, are not taken into account in existing algorithms. To solve this problem, this paper proposes an adaptively robust maritime celestial navigation algorithm, in which each observation value is given an equivalent weight according to the robust estimation theory, and the dynamic balance between astronomical observation and prediction values of vessel motion is adjusted by applying the adaptive factor. With this system, compared with the frequently used least square method and extended Kalman filter algorithm, not only are the real-time and high-precision navigation parameters, such as position, course, and speed for the vessel, calculated simultaneously, but also the influence of abnormal observation and vessel motion status change could be well suppressed.

Analysis of Imbalance Calculation Method in Dynamic Balancing Machinery

2017 ◽  
Vol 868 ◽  
pp. 218-223
Author(s):  
Jin Xiang Pian ◽  
Chun Yu Pu ◽  
Zhan Wang ◽  
Yuan Wei Qi
Keyword(s):  
Calculation Method ◽  
Dynamic Balance ◽  
Influence Coefficient ◽  
Improved Method ◽  
Dynamic Balancing ◽  
Actual Production ◽  
Experimental Environment ◽  
Development Direction ◽  
Influence Coefficient Method ◽  
Coefficient Method

The development of dynamic balancing machinery has gradually become mature. Experts and scholars have developed many kinds of actuators, which can achieve dynamic balance. But the imbalance in most dynamic balancing machinery is still obtained by using the influence coefficient method. In this paper, it made an analysis of the influence coefficient method and its improved method. The analysis indicates that, with the limitation of adding trial mass, these methods are mostly used in experimental environment. But for the actual production and processing, the feasibility of the application is not so hot. Therefore, looking for an imbalance calculation method without trial mass is particularly important, which is the development direction of dynamic balance technology in future.

Study on Dynamic Balance Weighting for Single-Disk Rotor System Based on Phase Difference Mapping

2012 ◽  
Vol 430-432 ◽  
pp. 1437-1441 ◽  
Author(s):  
Qing Liang Zhao ◽  
Hua Qing Wang ◽  
Jin Ji Gao
Keyword(s):  
Phase Difference ◽  
Dynamic Balance ◽  
Mechanical Vibration ◽  
Rotor System ◽  
Influence Coefficient ◽  
Weighting Method ◽  
Single Disk ◽  
Influence Coefficient Method ◽  
Rotor Mass ◽  
Coefficient Method

The rotor mass imbalance is main reason of rotating mechanical vibration. A new dynamic balance weighting method for single-disk rotor system based on phase difference mapping is presented. Firstly, the influence coefficient method and its characteristics are analyzed in detail. Secondly, the equivalent phase difference mapping relationship between incentive and vibration response for single-disk rotor system is proved by differential equations and Laplace transform theory. Finally, a specific application instance is showed. The new method is simple and easy to peel the phase coupling relationship between incentive and response, which can be used to guide dynamic balance weighting for single-disk rotor system on site.

A Method to Select Weights in Online Dynamic Balance Technology Based on Rotor-Active Magnetic Bearing System

2017 ◽  
Author(s):  
Yan Xunshi ◽  
Zhao Jingjing ◽  
Sun Zhe ◽  
Shi Zhengang
Keyword(s):  
Dynamic Balance ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Influence Coefficient ◽  
Rotating Speed ◽  
Balance Weight ◽  
Influence Coefficient Method ◽  
Short Time ◽  
Coefficient Method ◽  
Bearing System

Online dynamic balance technology is the key to rotor-active magnetic bearing system, which helps the rotating speed of the system surpass the critical speed. Usually, balance weight and angle are calculated by influence coefficient method. However, how to decompose the weight and angle into sub-weights fixed in the balance holes is troublesome, and determined manually by trial and error, which is always time-consuming. In this paper, a new hierarchical and automatic method is proposed to find the optimized solution to select proper sub-weights in a short time, which limits to a pre-defined error. The algorithm focuses on reducing the move of sub-weights and addition of new sub-weights. Experiments show our algorithm perform effective and efficient.

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