Development Of Automatic Measuring Instrument For Bearing’s Axial Clearance

Bearing is one of the key components in mechanical engineering and it’s performance has a crucial impact on the overall performance of a equipment. The axial clearance is an important quality index for a bearing, which affects the precision of rotation and positioning accuracy. And it is the reference to evaluate a bearing’s life and performance. Self-aligning roller bearing is a kind of widely used rolling bearing. At present, the measure of a self-aligning roller bearing’s axial clearance in domestic is static or half automation measurement. The measuring method is of low efficiency, large labor intensity and poor reliability; Usually one kind of instrument can only be limited to the use of a certain specific type bearing, which limits the mass production of the bearing. According to this situation, this paper puts forward a kind of automatic measuring instrument for self-aligning roller bearing’s axial clearance. This measuring instrument can be used in the self-aligning roller bearing’s production line, clamping and measuring its axial clearance automatically. In this paper, the main works are as follows:(1) According to the characteristics of self-aligning roller bearing and functional requirements of the measuring instrument, the scheme of each part is analyzed. Ultimately the scheme of each device and the action process are determined.(2) On the basis of overall scheme of the the equipment,the modules are divided. It is mainly divided into two big modules--the measuring instrument and the loading system. The measuring instrument includes rotational positioning device, load applied device and pushing device; The loading system consists of the conveyor belt, manipulator and filtering devices. According to the division of the module, the detailed structural design is carried on one by one and make them a whole machine finally.(3) Based on the mechanical structure, the paper analyzes the function requirement, hardware composition and control principle of the control system. At the same time, this paper introduces the design thought of PLC and VB software.(4) Various factors that may cause the measurement error are classified and their impact on measurement results are quantified. And the solution to minimize and avoid these errors are put forward. This equipment is designed for bearing’s automatic production line and it use PLC to clamp and measure the axial clearance autocratically. VB programming is used to deal with the test data and display the results.The instrument can find unqualified bearing during the measuring. It has a strong versatility and high degree of automation, which can be used for both stand-alone operations production line for different kinds of bearings. It greatly improves the production efficiency.