Calculation of Tooth Thickness Errors and Its Adjustment on Meshing Backlash of Harmonic Drive

• Published in: International journal of precision engineering and manufacturing Vol. 24; no. 2; pp. 289 - 301
• Main Authors: Yang, Congbin, Ma, Honglie, Zhang, Tao, Zheng, Jigui, Liu, Zhifeng, Cheng, Qiang
• Format: Journal Article
• Language: English
• Published: Seoul Korean Society for Precision Engineering 01.02.2023; Springer Nature B.V
• Subjects: Algorithms; Deformation; Deviation; Engineering; Industrial and Production Engineering; Interference; Materials Science; Mathematical analysis; Meshing; Regular Paper; Teeth; Thickness; Dimensions of over pins; Radial deformation; Backlash; Involute profile; Tooth thickness deviation
• ISSN: 2234-7593; 2005-4602
• DOI: 10.1007/s12541-022-00738-8

Meshing backlash mainly determines the transmission accuracy of harmonic drive, which is an important index in design. In this paper, a design method for short tooth involute profile is proposed. By intercepting part of the tooth profile, meshing interference of the addendum can be effectively avoided. Based on the dimensions of over pins of circular spline and flexspline, a calculation method of tooth thickness deviation is proposed, and the positive and negative tooth thickness deviation are defined. Involute functions need not be calculated by this method, which simplifies the solution process. By discretizing the teeth profile points of circular spline and flexspline, a calculation method of time-varying backlash is proposed, the variation of backlash in meshing in and out is analyzed, and the influence law of tooth thickness deviation on backlash is studied. On this basis, an algorithm for adjusting the radial deformation to compensate for the backlash is proposed. The results show that the excessive backlash in the meshing area can be reduced by increasing the radial deformation. When meshing interference occurs, the interference-free meshing can be realized by decreasing the radial deformation.