Error Analysis Of Gear Measuring On-machine Based On Rack-shaped-edge Probe

Gear is used frequently as important transmission part and critical fundamental elements of mechanical equipment in industrial production and mechanical equipments. The requirements for accuracy of gear are higher and higher with the developments of scientific technology and production. But the gear with excellent performance, high quality and high accuracy cannot be manufactured without advanced detection technique and measuring instruments, so the detection technique has important position in the gear manufacture.Gear measuring technology can not develop without the development of the theory of precision gear, and they are related to each other, so this paper describes the developments of them. The meshing theory for involute gear is described on the basis of differential geometry, it includes that the research for equations and properties of the involute helicoid, and the analysis for four group representative cures:the group of involute, helix, contact trance and straight generatrix. At the same time, medium rack is taken as tool for better analyzing the point meshing theory of crossed axes, and the fundamental for expansion of paper is established.According to the three deviation-measuring items of single error of gear that must be detected, the measuring technology on-machine for profile deviation, individual circular pitch error and helix deviation is analyzed, and the program of on-machine with rack-shaped-edge probe is put forward based on analysis and comparison. On the basis of the relationship of helix error, contact trance error and straight generatrix error, the measurement of measuring straight generatrix error instead of helix error measurement is proposed, that is:through measuring deviations of straight generatrix family on tooth profile, and the error-separating mathematical model is established based on straight generatrix deviation, the tooth profile deviation and helix deviation are thus separated by data processing. The measuring equipments of gear measuring on-machine based on rack-shaped-edge probe are described, what's more, the main errors which may be appeared in measuring process are researched, and the errors which influent the measuring accuracy are analyzed, including the manufacturing error of measuring equipments, installation errors, shape errors of working table and elasticity creep of two rolling discs. The mathematical equations is derived and established and the accuracy is verified by taking specific gear for example. The error is in range of total errors that is permitted and meets the requirement of high accuracy by verification, so it is feasible. At the last the measurements which used to guarantee the measuring accuracy is summarized.