spur wheel countershaft

• 正齿轮副轴

spur wheel countershaft的用法和样例：

例句

1. A combination countershaft and planetary gear set transmission is provided that achieves at least nine forward speed ratios and two reverse speed ratios.
   提供了组合副轴和行星齿轮组变速器，它实现了至少九个前进速比和两个后退速比。