Research And Development On A Measurement System For The Groove Curvature Radius Of Ball Bearings

Bearings are one of the most important elements in modern industry. Ball bearings are the most widely used among them. The groove curvature of ball bearings has an impact on rotation accuracy, clearance, contact angle, vibration, noise, friction and other dynamic performance. Furthermore influence the operating accuracy of the machine equipped the bearings. Therefore, it is a very important performance index of ball bearings. Currently the most widely employed methods for measurement of the groove curvature of ball bearings are non-digital or non-professional. This is contrary to the trend of digital manufacturing in modern industry. So it is very important to study the measurement theory of the groove curvature radius, to develop the measurement system, and to obtain the high accuracy of the curvature radius of the ball bearings.This paper provided a theory of ball bearing groove curvature measuring system and built the mathematical model of the system. Since the cross-section of the work surface of ball bearings is arc, get the coordinate value on the surface by contact profile measurement and furthermore fit the coordinate to an arc. The radius of the arc is the value of the ball bearing groove curvature radius that needed.Based on the former theories, I have designed the measuring system conclude of mechanical part, measurement and control part. The mechanical part is composed of Z-direction structure and X-direction structure. The function of mechanical part is to provide the movement for measuring. The measurement and control part is composed of hardware and software. The hardware works by the cooperation of PLC and the industrial control computer to realize the automation of measuring process. The software mainly obtains the profile and the measurement result of the groove curvature radius of the ball bearing by data acquisition interface and data processing program based on LabVIEW.In the end is the experiments to prove the measurement accuracy of the system. the result tells that, the repeated measurement accuracy for measuring the groove curvature radius of ball bearings is 0.5um, the repeated measurement accuracy is ±2um. It has realized the target to measure the groove curvature of ball bearings with high accuracy. And it has met the need of practical use.