Research on Processing Error of Special Machine Tool for VH-CATT Cylindrical Gear

Abstract

The variable hyperbolic circular arc tooth trace (VH-CATT) cylindrical gear is a new gear suitable for heavy loads and high speed. The special structure of the gear provides excellent mechanical properties but also increases the processing difficulty. The special machine tool for VH-CATT gear provides a prerequisite for mass production, but the machining accuracy remains to be improved. Therefore, this paper proposes a Kriging model based on the glowworm swarm optimization algorithm of scene understanding (SGSO) to study the relationship between input parameters and output precision. Then, the SGSO algorithm is used to optimize the parameters of the Gaussian mutation function in the Kriging model to improve its fitting accuracy. When solving four groups of tooth profile and tooth direction errors, the key precision index, R2, of SGSO-Kriging all exceed 0.95. Additionally, the feasibility of the model is verified by the residual diagram and the box diagram. The contour diagram and error results show that reducing the feeding velocity, vf, can improve accuracy most efficiently, and the increase of rotational speed, n, is more conducive to the accuracy of the tooth surface than the acceleration of the coolant, vQ. The above research provides an optimization strategy of gear machining accuracy and a theoretical basis for the promotion of the VH-CATT gear.

Geometric contact characteristics of variable hyperbolic circular-arc-tooth-trace cylindrical gear under different machine tool errors and sensitivity analysis for impact factors

“…The tooth surface equation of the cylindrical gear with variable hyperboloid arc tooth line under ideal condition can be obtained by combining the equations ( 6) and (13).…”

“…Based on the forming principle of large cutter head and the meshing condition of gears, the tooth surface mathematical model and TCA model with installation error of VH-CATT gears were established by Wei et al, 12 who analyzed the effects of different installation errors and design parameters on the geometric contact characteristics and sensitivity of gear pairs. In order to improve the machining accuracy of VH-CATT gear, a model based on optimization algorithm was proposed to study the relationship between input parameters and output accuracy by Liang et al 13 Liu and Ma 14 proposed a tooth surface modification design method based on parabolic forming edge and tool inclination for VH-CATT gear, which analyzed the influence of modification parameters on the curvature characteristics and the elliptical contact area. Chen et al 15 proposed a new algorithm for reverse adjustment of tooth surface accuracy control of spiral bevel gears, established a mathematical model of tooth surface, and studied the influence of machining error on contact characteristics.…”

Contact Stress Reliability Analysis Model for Cylindrical Gear with Circular Arc Tooth Trace Based on an Improved Metamodel

“…The gear is milling by a rotary cutter with a straight cutter edge, and the gear tooth line obtained by cutter milling is a space circular arc line. The tooth profile found in the middle section is an involute line, while the other sections consist of envelope lines from a hypercurve family with consistent transitions, so it is called VH-CATT [24]. These features make the gear less sensitive to coaxiality installation errors, resulting in benefits such as reduced noise, a high degree of alignment, and a simplified structure.…”

Approximation Model Development and Dynamic Characteristic Analysis Based on Spindle Position of Machining Center

“…The statistical characteristics of z(x) are the covariance between random variables corresponding to two different points in the design space [ 27 , 28 , 29 , 30 ]. where represents the correlation function between two sample points, and θ is the relevant parameter.…”