Research On Online Automatic Measurement Technology For The Width Of Tapered Roller Bearing

With the development of the equipment manufacturing industry, automatic assembly technology of roller bearing, as highly interchangeable standard component part, attracts more and more attention and is widely used in the productions. Thus the online automatic measurements of finished bearings are required urgently by the manufactures. Based on the background of research and design of an online measurement system which is set in an Automatic Assembly Line for the Tapered Roller Bearing in Xiangyang Automobile Bearing Co., Ltd, the online automatic measurement technology for the tapered roller bearing width has been studied in this thesis.The characteristics and methods of existing instruments for bearing width measurement have been introduced and the function demands of online automatic measurement system for the tapered roller bearing have been analyzed, and then a scheme developing the system has been worked out in this thesis. According to the scheme, the system with an inductance micrometer is based on mechanisms suited for online automatic measurement and it has been developed by means of PLC and virtual instrument technology.Mechanisms of the system mainly include a measurement mechanism and a selection mechanism. The ideas, basis and results of designing the mechanisms have been introduced here. According to the principle measuring bearing width and the method appointed in National Standards, measurement mechanism has been developed. Imitating manual measurement, it can automatically and pneumatically implement measurement procedure including preliminary positioning and precision positioning of the measured bearings. All the measured bearings are picked over and then the selection mechanism can automatically push the unqualified bearings out of the production line.Based on the mechanisms and according to the demands of data acquisition and the actions of measurement and separation, the control system has been developed including its mechanical and electrical hardware and corresponding control and calculation software. There are three parts of the control system, which are movement procedure control, bearing width measurement control and I/O interface module between PLC and IPC. Then the thesis has presented the design contents of each part. Movement procedure control implements the actions of measurement and selection mechanisms through controlling the pneumatic devices by PLC. The measured signals are sampled and then processed by the IPC. The communication between PLC and IPC is finished by the I/O interface module. PLC informs IPC simultaneously to start sampling just when the precision positioning of the measured workpiece is finished. Afterwards IPC sends the measured result to PLC for controlling the selection mechanism. Based on virtual instrument technique, the software has been programmed by LabVIEW. They supply good interfaces for debugging operation, result display, trouble warning and so on.Final part of the thesis, experimental verifications for the developed system have been given. The errors caused by mechanisms have been analyzed emphatically and some measures have been taken to eliminate them too. Experimental results show that the accuracy of the system is±8.5μm, and its efficiency is 16 s/set. The developed system, with higher accuracy and speediness and also without operator, can satisfy the requirement of bearing width automatic measurement in the automatic assembly-line for the tapered roller bearing.