【作者】 薛云娜；

【导师】 王勇；

【作者基本信息】 山东大学 ， 机械制造及其自动化， 2006， 博士

【摘要】 齿形链传动广泛应用于汽车、摩托车等汽油发动机的正时机构，然而齿形链传动固有的多边形效应和啮合冲击一直制约着齿形链机构的进一步发展，亟需研究新型齿形链传动来提高齿形链机构的传动性能。本文通过分析齿形链传动过程中存在的多边形效应和啮合冲击，开展了双面啮合齿形链传动啮合理论与应用研究。 以减小多边形效应为目标，提出了双面啮合的啮合形式，双面啮合的特点是齿形链条的内外侧齿廓均可与链轮轮齿啮合。啮合周期的初始阶段，链条的内侧直线齿廓与链轮啮合，啮合周期的终止阶段，链条的内外侧齿廓同时与链轮的齿廓线啮合，链条依靠外侧齿廓定位于链轮上。双面啮合齿形链条拉紧时，内侧齿廓和外侧齿廓平行且外凸于外侧齿廓。 系统研究了双面啮合齿形链传动的啮合理论，设计了双面啮合齿形链机构，该机构由双面啮合齿形链条和新型链轮组成。首先，为减小多边形效应的幅值，设计了内外侧双面齿廓均可与链轮啮合的齿形链条，开发了双面啮合链板参数分析软件。其次，根据包络原理推导出与链条外侧齿廓共轭啮合的链轮齿形，通过理论验证发现该齿形为大负变位大压力角的渐开线。研究了新型链轮的齿形修正方法，设计了可与双面啮合链条配合的新型链轮齿形。最后，研究了新型链轮的齿形特性，推导出新型链轮齿形参数的计算公式。研究发现，当新型链轮唯一变位系数的绝对值小于最小变位系数的绝对值时，新型链轮加工时不会产生根切。 发展与完善了双面啮合齿形链机构的设计理论。提出了双面啮合齿形链条和新型链轮的设计方法和实体建模方法，给出了新型链轮的设计参数方程，开发了齿形链链轮的设计软件。研究了新型链轮刀具和链轮加工机理，对链轮毛坯进行加工仿真，动态模拟了新型链轮的切齿过程。 建立了齿形链机构的运动学模型和啮合冲击模型，动态模拟了双面啮合齿形链机构、传统链条渐开线链轮机构和传统齿形链机构的啮合过程，对三种齿形链机构进行动力学仿真。结果表明：与传统齿形链机构比较，双面啮合齿形链机构的紧边链条波动量、啮入冲击速度系数、冲击动能和瞬时接触力均有所减小。 通过传动及动态性能实验，分析了三种齿形链机构的传动性能，测定了链传动实验台和齿形链条横向振动的固有频率，进行了紧边链条波动量、振动和噪音更多还原

【Abstract】 Silent chain drive is widely used in the timing mechanism of gasoline engine, such as motorcar and motorcycle engine. However the polygon movement and the meshing contact of silent chain drive are great obstacles in the further development and application of the silent chain mechanism. It is necessary to develop new kind of silent chain drive to improve the transmission performance of silent chain mechanism. The meshing theory and application of the dual meshing silent chain drive are investigated to reduce the polygon movement and the meshing contact.The dual meshing is presented in order to reduce the polygon movement. The characteristic of the presented dual engagement form is that both sides of the silent chain tooth form can engage with the sprocket tooth form. At the beginning of a meshing circle, the inner straight tooth form of the silent chain engages with the sprocket form. At the end of a meshing circle, both sides of the silent chain contact with the sprocket form. The dual meshing silent chain depends on its outer tooth flank to wind around the sprocket. The inner tooth form of link plate is profiled to parallel and project outward of the outer tooth form as the dual meshing silent chain is stretched into a line.The meshing theory of the dual meshing silent chain drive is systematically investigated. The dual meshing silent chain mechanism is designed, which comprises the dual meshing silent chain and new kind of sprockets. First, both forms of silent chain, including the inner form and the outer form, are designed to mesh with the sprocket in order to reduce the amplitude of the polygon movement. According to the envelope principle, the approach to solve the sprocket tooth profile conjugated with the outer tooth form of dual meshing silent chain is presented. The result shows that the sprocket tooth profile is an involute surface with large pressure angle and large negative addendum modification coefficient. Second, in order to acquire the new kind of sprocket, the sprocket tooth profile is modified. Finally, the characteristic of the sprocket tooth profile is studied and the parameter function of the sprocket tooth profile is derived. The analysis results show that the undercut would not generate in the course of sprocket processing as the absolute value of the unique modification coefficient is smaller than that of the minimal modification coefficient.更多还原