Research On Worm Gear Laser Precision Measurement Technology

Worm transmission is an important transmission system in the field of industrial automation.It is widely used in machine tools,automobiles,instrumentation,metallurgical machinery and other machines or equipments.In order to ensure the accuracy of transmission,working stability and reliability of the worm transmission,the quality of the worm and worm gear must be tested.Nowadays,the contact CNC coordinate measuring technique is widely used as measuring method of worm and worm gear.By this measuring method,the motion path of the measuring sensor should be planned,which is according to the tooth profiles of the tested worm and worm gear.Therefore,this measuring method has some problems such as poor generality and low efficiency.In order to solve these problems,the study of advanced measuring technology of worm and worm gear become more and more important.Based on the analysis of the characteristics of existing worm and worm gear measuring technology,this paper explored more precise and efficient measuring methods.A non-contact measurement based on laser displacement sensor and corresponding calculation method of tooth profile and pitch error were put forward.On the basis of consulting a large number of domestic and foreign literatures on worm gear and worm gear and the CNC coordinate measuring technology,the ideal model of common straight surface cylindrical worm and worm wheel tooth profile is established by using the spatial geometric coordinate calculation method.The axial profile of worm and the specific end section profile of the worm gear tooth surface were measured by laser displacement sensor.Through cubic least square curve fitting method fitting the measurement sampling point and calculate the smooth curve,using the indexing position point of tooth profile of the smooth curve to locate the ideal tooth position.According to the definition of error in the GB,tooth profile error and pitch error are calculated by using the coordinate calculation.The overall design of the measuring instrument based on the laser displacement sensor was designed in this paper,and the actual construction was completed.The measuring instrument was mainly composed of three axis linear motion guide with grating feedback,a rotation measuring platform with grating feedback and a laser displacement sensor that can freely adjust the pose angle.The motion control of each shaft servo motion was realized through the ADT850 control card and the control program.According to the principle of laser measurement and the calculation of tooth profile error and pitch error,paper have compiled the measuring system software,which can achieve the function of motion control and the error analysis of the measured parts.The measuring experiment of ZI worm,ZA worm and worm gear has been finished,which can prove that the laser measurement and the calculation of tooth profile error and pitch error are feasible.Moreover,the measuring experiment is also able to prove that the laser measurement put forward on the paper has higher efficiency and stronger generality.