基于螺旋非圆齿轮变速装置设计研究

为增加变速器带载换挡能力，解决摩擦片发热烧毁等问题，提出利用非圆齿轮传动替代摩擦传动换挡结构；研究渐开线变厚齿面形成原理，通过增加共轭齿条周向纯滚动和轴向运动约束条件，建立螺旋非圆齿面包络加工数学模型，描述共轭齿条各段齿面失径，推导螺旋非圆齿面方程；利用数值计算实例验证了数学模型的正确性，分析非圆齿的几何特征与轴向移动速度之间的关系，说明共轭齿面仍为线接触；通过对锥齿轮组进行详细设计与动力学仿真，结果显示角速度输出曲线较为平稳，仍存在一定轻微冲击；搭建基于机电检测方案的锥齿轮组自动变速装置试验平台，实现了档位自动变换功能，进一步验证了螺旋非圆齿轮基本啮合原理且锥齿轮组改造设计方案具备一定的可行性。

Design and Research of Variable Speed Device Based on Spiral Noncircular Gear

In order to increase the shifting process capacity of transmission and to solve the problem of calorific or burn down of the friction plate, it proposes to make use of non-circular gear transmission instead of friction drive shifting process structure. Formation principle of involute beveloid tooth flank is studied. By increasing conjugate rack circumference pure rolling and axial motion constraint condition, a mathematical model of spiral non-circular gear enveloping machining is established. Each tooth flank vector radius of conjugate racks is described, and the spiral non-circular tooth flank equation is deduced. The numerical example is used to verify the accuracy of mathematical model and the relationship between the geometrical characteristics of non-circular tooth and the axial movement velocity are analyzed. The results show that the conjugate tooth flank is still in line contact. Through the detailed design and dynamic simulation of the bevel gear, the results show that the angular velocity curve is relatively steady and with slightly impact. The establishment of bevel gears based on electromechanical detection scheme and automatic speed changing devices test platform make features of gear automatic shift come true and furthermore verify basic gear meshing principle of spiral non-circular gears. The design and rebuild scheme of bevel gears train have certain degree of feasibility.