Abstract:

A new type of differential with variable ratio for off-road vehicles was put forward, in which the transmission ratio varied at a circle of the planetary gear, which had half the number of the teeth of the half-axle gear. The variable range of ratio can go extreme as much as ±40%, resulting in locking coefficients of 2.33(theoretical) and 3.15(practical), which would be of great help to improve the passing capability of the vehicle. Based on the round trip mapping algorithm with preserved geodesic curvature between a sphere and a plane, the design methods of the pitch curves as well as the tooth profiles were presented, and an actual case study was illustrated to show the effectiveness of the new differential. 

Key words: differential, variable ratio, non-circular bevel gear, off-road vehicle

摘要：

提出了一种新型变速比差速器,行星齿轮与半轴齿轮齿数之比为1∶2,传动比以行星齿轮转一圈为一个变化周期,突破了齿数与周节的限制,可以最大限度地提高传动比的变化幅值(达到±40%),增大差速器的锁紧系数。给出了该差速器锥齿轮的设计原理与方法,包括非圆节锥与节曲线设计、球面-平面映射、齿形设计等,并进行了实例验证。试验结果表明,新型差速器达到了设计预期,理论和实际锁紧系数分别为2.33和3.15,可以显著提高车辆的越野通过性。

关键词: 差速器, 变速比, 非圆锥齿轮, 越野汽车