Research On Tooth Profile Design Method Of Micro-gear Based On Cubic Spline

In this paper, a new method called"piecewise cubic spline"for generating conjugating gear profiles is proposed. The relative formulas are derived and involutes'gear is analyzed by the use of this method. When the points on original cutters or tooth profiles are gotten, the profile of gear will be solved by piecewise cubic spline.Secondly, according to the design and manufacture characteristics of the micro-gear, the direct design method called"deviation function"is discussed. This method is to use deviation functions to reshape the tooth profiles based on the original pitch pairs. It is applicable to any type of pitch pairs and relatively easy to realize the desired geometrical and mechanical properties in the design. By this method, the gear drives have small sliding coefficients and contact stress. Therefore, the gear wear is effectively reduced. The sliding coefficients, the bending stress, the contact stress and curvature radius of micro- gear based on new profile is calculated, compared with the involutes'gear. The effect of modulus and tooth number on micro-gear performance parameters is analyzed. The three-dimensional solid model of micro-gear is built in Pro-E, and then it is convenience for the numerical analysis of mechanical parameters.Thirdly, using the finite element analysis software ANSYS, the bending stress and of the micro-gear are analyzed, and compared with the approximate result of analytical analysis. The theoretical analysis results indicate that micro-gear based on new profile is better than involutes'gear in mechanical characteristics.