Jing Ling Zhou

Finite Element Analysis of Thrust Bearing Magnetic Field in 22KW Spindle

There is a magnetic field inside thrust bearing. The magnetic field distribution is one of the key factors which decide the running state and performance. With the finite element of ANSYS software, the magnetic field of thrust bearing has been analyzed. The rule of changes between the magnetic field and the influencing factors has been discovered. The analysis shows that the direction of exciting current should be opposite other than identical. The greater the ratio of gap length between stator and rotor and working gap length is, the less magnetic field leakage is. The flux leakage of thrust bearing attains 37 percent when the ratio of the gap is 4.0. If the design of a complete machine is not proper, the flux leakage may attain 20 percent upwards through other gaps although that of the bearing itself is almost zero. Calculation of bearing capacity indicates that theoretical value is not exact due to its neglect of magnetic saturation and flux leakage, while FEM value comparably matches the real substance with considering the magnetic saturation and flux leakage. The research provides the theoretical basis for optimization of system structure and selection of current direction control.

Vibration Test of Bearing Ball Fatigue Testing Machine Based on VB

Ball bearing life test, once the failure specimen ball fatigue, if not timely shutdown, will lead to a series of chain reactions caused by the fault processing is not seasonable, serious word may also lead to the damage of equipment. Therefore the vibration test is very important to accurately determine the specimen failure, ball. In this paper, the vibration test for bearing fatigue testing machine, the test results to be real-time and accurate judgment sample ball failure.

The Friction and Wear of Silicon Nitride Ceramic with BSA Lubricant

To research the friction and wear of silicon nitride ceramic with bovine serum albumin lubricant, the tribological properties of silicon nitride ceramic against stainless steel were investigated on CETR UMT-2 under lubrication of bovine serum albumin, deionized water, physiological saline and physiological saline mixed with bovine serum albumin. The worn surfaces of silicon nitride ceramic ball and stainless steel pin were examined with a digital microscope (VHX-2000). The friction coefficients of steady state are 0.26, 0.35, 0.69 and 0.8 under bovine serum albumin, physiological saline mixed with bovine serum albumin, physiological saline and deionized water. The lowest friction coefficient of steady state is 0.26 which is under lubrication of bovine serum albumin. The highest friction coefficient is 0.8 under the lubrication of deionized water. The measured worn areas of silicon nitride ceramic balls are 1282.3μm2, 1898.6μm2, 2753.9μm2 and 3645.7μm2 under bovine serum albumin, physiological saline mixed with bovine serum albumin, physiological saline and deionized water. The smallest worn area of silicon nitride ceramic ball is 1282.3μm2 which is measured under the lubrication of bovine serum albumin. The highest worn area of silicon nitride ceramic ball is 3645.7μm2 which was measured under the lubrication of deionized water. The same wear mechanism of silicon nitride ceramic ball had been found under the lubrication of bovine serum albumin, deionized water, physiological saline and physiological saline mixed with bovine serum albumin. The depth of scratches of worn surface of silicon nitride ceramic ball lubricated with BSA is 3μm which are the shallowest.

Tribological Characteristics of Silicon Nitride Ceramic in Three Water-Based Lubricants

The friction coefficient of tribology pair between silicon nitride ceramic and stainless steel was researched with bovine serum albumin, saline and water lubricants. The coefficient of friction of silicon nitride in bovine serum albumin is lower than those in saline and water. Using digital microscope, the worn surfaces of silicon nitride and stainless steel were viewed. The groove depths of worn stainless steel surface were measured. The depth with bovine serum albumin is shallower than those in saline and water. The results showed that ceramic in bovine serum albumin has good tribological characteristic. This research provides the reference for the development of ceramic artificial joint.

Power Spectrum Analysis Based on VB Language

Power spectrum analysis is one of the important part of digital signal processing, various characteristics of the main signal in the frequency domain, is designed based on the limited data and extract the useful signal is submerged in the noise in the frequency domain. In this paper, the VB language to realize the power spectrum analysis can extract the useful signal was drowned in noise in frequency domain based on power spectrum, frequency structure and physical meaning analysis reflected the more obvious, monitoring and diagnosis in rotating machinery fault, power spectrum analysis is very wide.

Surface Roughness Measurement Analysis

The surface roughness is a physical quantity of micro geometry error surface material used for assessment of processed composed of peak, valley and the spacing of the. Have a great influence on the parts usage. Generally speaking, the surface roughness is small, can improve the matching quality, reduce wear, extending the service life of parts, but the processing cost of parts will increase. Commonly used assessment parameters can be divided into height parameters, spacing and shape parameters (parameter) three series. Measurement methods are commonly used surface texture tester, optical surface profiler and atomic force microscope. This paper makes a comparative analysis on the different measurement methods.

Modal Analysis and Application Based on Finite Element Method

Mode is the natural vibration characteristics of the mechanical structure. Each mode has the specific natural frequency, damping ratio and modal shape. These modal parameters can be obtained by the calculation and experimental analysis. A calculation or test analysis process is called modal analysis. The analysis process is achieved if calculated by the finite element method, is called the analysis of calculating mode. The spindle mode of driving roll was analyzed in this paper. If clear structure in one easy frequency affected range of each order main modal characteristics through modal analysis method, it can predict the vibration response of this band structure of external or internal variety under the action of vibration. Therefore, the modal analysis is an important method for fault diagnosis of structure dynamic design. Comparing theory results with finite element results indicated that the error was less than 10 percent. The accuracy on the shaft modal analysis finite element method was improved.

Correlated and Coherent Analysis Based on Vibration Data of Fatigue Life Test Rig for Ball with Three Point Contact

The exciting input signals of the parts in a fatigue life test rig for ball with three point contact and the system’s output signals were analyzed by auto-correlation and cross-correlation with MATLAB software, which eliminated the impact of noise to a certain extent and got the response signals of same frequencies caused by exciting input signals. Finally, the result showed that the text rig was linear by coherent function analysis, which provided the theory basis for modal and dynamic analysis further.

Finite Element Analysis to Ceramic Ball Pure Rolling Contact Stresses

The RCF (Rolling Contact Fatigue) life of bearing balls is a main method, to evaluate the performance of bearing materials and their production technology. In general, The RCF life of ceramic balls is a reliable technique to asses whether or not they are suitable to be used in rolling bearings. The RCF life of ceramic balls is depend on contact stresses chiefly. It applies the finite element analysis to calculate the surface stresses and subsurface stresses, including 1st principal tensile stresses and shear stresses. The theory results are compared with the finite element solutions. Very good agreement is observed. The finite element results in this paper have an important applied value. The results provided theoretical basis for rolling contact fatigue life prediction of the ceramic balls.

The Modal Analysis of the Ceramic Ball’s Rolling Contact Fatigue Tester’s Drive Shaft

The Modal Analysis of the Ceramic Ball Rolling Contact Fatigue Life Test Rig Drive Shaft Abstract: With the increasing of the rolling contact fatigue life tester’s speed, the vibration problem is getting more and more serious. In order to optimize the dynamic performance test rig, the modal analysis of the drive shaft was carried. First the vibration mechanics model was got by simplifying the shaft and get the first order of horizontal natural frequency which is 787.4266Hz with the theoretic algorithm. Then the drive shaft’s modal analysis was made by using the finite element software and that is 779Hz. The relative error between the former and the latter is 1.1%. It has demonstrated the accuracy of the finite element result, and its modal analysis could be the basis of the dynamic optimization.