Gear is an important basic part of industrial equipment. With the development of modern industrial technology, higher requirements are put forward for gear design. Gear modification is an effective method to reduce the vibration and noise of gear transmission. Among them, gear alignment modification can reduce the impact of meshing in and out of gear transmission, improve the uneven distribution of load along the contact line of teeth, reduce vibration and dynamic load, and improve the transmission accuracy, bearing capacity and service life of gear.
However, there are some machining errors in the grinding process of the tooth profile modification helical gear, and the tooth surface is easy to be distorted, which affects the manufacturing accuracy of the tooth profile modification helical gear. For this reason, Guo Er Kuo et al. Established a mathematical model of tooth profile modification error in form grinding, and put forward a method to improve the tooth surface distortion by adjusting the grinding wheel installation angle to optimize the contact line. Tran VT et al. Put forward a method to reduce the tooth twist by adding an additional angle of the gear when grinding the modified gear. Li Guolong et al. Put forward an improved design method of commonly used drum tooth modification curve. The modified curve was divided into three sections. By adjusting the scale factor of the three sections of curve and the drum shape of each part, the distortion of tooth surface was reduced. He Kun et al. Proposed a method to reduce the distortion error of tooth surface based on multi axis additional motion optimization. However, the tooth surface equation of helical gear is not derived based on tool modification, and the quantitative analysis of the mechanism of tooth surface distortion is not enough, and the influence of tooth surface distortion on the meshing performance of helical gear is not analyzed.
The generation mechanism of tooth surface distortion is studied quantitatively, and the tooth surface distortion coefficient with more geometric significance is proposed to represent the degree of tooth surface distortion. The tooth surface distortion model based on the grinding or hobbing method of diagonal worm is derived, and the influence law of tooth surface distortion on the meshing performance of helical gear pair with profile modification is analyzed. This work is helpful to the further analysis and research of tooth surface distortion in gear precision machining.
(1) In this paper, the mechanism of tooth surface distortion in grinding or hobbing of helical gear worm with tooth profile modification is analyzed. The tooth surface distortion coefficient with more geometric significance is proposed to represent the degree of tooth surface distortion. The calculation model for the matching of axial feed rate and diagonal feed rate ratio with tooth surface distortion is obtained, which has guiding significance for worm grinding and the design of machine tool control software. In this paper, the theoretical analysis of the mechanism of the distortion of the generating method is mainly made. Further experimental verification needs to be combined with the specific type of machine tool and processing technology.
(2) The tooth surface distortion is closely related to the transmission error and the bearing capacity of the gear. The quantitative correlation law is given, which can be used to guide the analysis of actual gear meshing performance.
(3) This paper presents an analysis method of tooth surface distortion and meshing performance of helical gear with tooth alignment modification: CAD / CAE integrated analysis method based on MATLAB, CATIA and finite element commercial software, which provides a method reference for the analysis and research of gear high quality design.