大重合度组合齿廓非圆齿轮设计方法试验研究

Experimental study on design method of non-circular gear with high contact ratio and composite tooth profile

为了解决组合齿廓非圆齿轮增大重合度问题,对组合齿廓非圆齿轮设计方法进行了研究。首先,提出了增大齿高系数,减小节曲线压力角、负变位的组合齿廓非圆齿轮设计方法,对变渐开线-不完全变摆线齿廓展开了大重合度组合齿廓设计,并对大重合度的非圆圆柱齿轮进行了设计;然后,分析了齿高系数、变位系数、节曲线压力角与非圆齿轮渐开线齿廓和变渐开线-不完全变摆线组合齿廓的重合度变化规律,制造了2种增大重合度的组合齿廓非圆齿轮;最后,测量了增大齿高系数和减小节曲线压力角的非齿轮齿侧间隙,并与标准的渐开线齿廓齿侧间隙进行了对比,开展了大重合度组合齿廓非圆齿轮传动比的测量试验,以及承载能力仿真对比分析(主动轮固定,从动轮添加15 N·m扭矩)。研究结果表明:组合齿廓非圆齿轮的齿侧间隙(减小节曲线压力角0.106 mm,增大齿高系数0.107 mm)明显小于渐开线齿廓非圆齿轮的齿侧间隙(0.173 mm);大重合度组合齿廓非圆齿轮的试验传动比与理论仿真传动比一致;减小节曲线压力角的大重合度齿廓设计方法承载能力(应力最大值157.5 MPa)最优,增大齿高系数的大重合度齿廓设计方法承载能力(应力最大值213.2 MPa)最差。采用增大齿高系数,减小节曲线压力角的组合齿廓非圆齿轮设计方法来实现非圆齿轮的大重合度设计是可行的。

In order to solve the problem of improving the contact ratio of non-circular gears with composite tooth profiles,the design method of non-circular gears with composite tooth profiles was studied.Firstly,a design method for composite non-circular gears with increased tooth height coefficient,reduced curve pressure angle,and negative displacement was proposed.The design of high contact ratio composite tooth profiles for variable involute incomplete variable cycloid tooth profiles was carried out,and the non-circular cylindrical gears with high contact ratio was designed.Then,the variation law of tooth height coefficient,modification coefficient,and pitch curve pressure angle on the contact ratio degree of non-circular gear involute profile and variable involute incomplete variable cycloid composite profile was analyzed,and two types of non-circular gear composites with increased contact ratio were manufactured.Finally,the tooth backlash of non gears with increased tooth height coefficient and reduced curve pressure angle was measured and compared with the standard involute tooth profile tooth backlash.The measurement tests on the transmission ratio of non-circular gears with large composite tooth profiles were conducted,and the comparative analysis of their load-bearing capacity(the driving gear was fixed,and a torque of 15 N·m was added to the driven gear)was simulated.The research results show that the tooth backlash of non-circular gears with composite tooth profiles(reducing the curve pressure angle by 0.106 mm and increasing the tooth height coefficient by 0.107 mm)is significantly smaller than that of non-circular gears with involute tooth profiles(0.173 mm).The experimental transmission ratio of non-circular gears with large composite tooth profile is consistent with the theoretical simulation transmission ratio;the design method of high contact ratio tooth profile with reduced curve pressure angle has the best load-bearing capacity(maximum stress value 157.5 MPa),while the design method of high contact ratio tooth profile with increased tooth height coefficient has the worst load-bearing capacity(maximum stress value 213.2 MPa).It indicates that the composite tooth profile non-circular gear design method of increasing the tooth height coefficient and reducing the pressure angle of the pitch curve is effective for increasing the high contact ratio of non-circular gears.