Small small-sized bearing size

1. 3 the development trend of rolling bearing vibration and noise research 1. The noise measurement and measurement standards is mainly developed a portable measuring instrument noise, field measurement and analysis of the noise. The problem is the basic condition of batch production of low noise bearings. Japan has already reported about the bearing noise measurement standard. Although foreign developed a portable measuring instrument noise, but except use not convenient, the most important issue is not the noise measuring instrument has overcome the two main difficulties: background noise isolation effect and time domain noise signal picking errors. Relative measurement microphone bearing Angle and distance measurement standard must be considered. 2. Bearing noise sound pressure level of the research in the bearing noise measurement uncertainty, the evaluation of uncertainty of measurement is a very important question, to the measurement of small sample, the expanded uncertainty of bearing noise sound pressure level, in order to evaluate each set of bearing noise sound pressure level of expanded uncertainty, and predict the sound pressure level of the mass production of low noise bearings. The uncertainty of bearing noise research will depend on the fuzzy set theory, the grey system theory, the maximum entropy principle or the bayesian theory and so on, the difficulty is that few measurement data and probability density function of the unknown. 3. Noise mechanism research must break through the bearing vibration and noise diagnosis theory research of the status quo, introducing friction vibration and acoustic, impact vibration and acoustic and non linear dynamics theory, pay attention to the research of uncertain information order and randomness. FT the seemingly random error of harmonic spectrum graph, without doubt is a sign of nonlinear factors. The quality of the roller, Weight) Is can't avoid noise mechanism and noise diagnosis theory research. Roll body and ring raceway of the nonlinear contact deformation inevitably cause nonlinear vibration of rolling element. The cage moving, the pocket hole clearance and the interaction between roller and other sports, Collision, friction, etc. ) Is the noise mechanism and the difficulties of the noise sound diagnosis theory research. Many non-quantitative and fuzzy factors, For example, cleaning, lubricating grease, etc. ) Quantitative description of sound noise contribution is still the unity of theory and practice of noise noise barrier.