speed changer的用法和樣例：
例句
- Step Speed Changer and Magnetic Clutch to adjust the belt speed for stable feeding and spacing between blanks.
採用變速器和磁性離合器調整送紙皮帶速度，確保送紙及輸紙步距的穩定。 - A combination countershaft and planetary gear set transmission is provided that achieves at least nine forward speed ratios and two reverse speed ratios.
提供了組合副軸和行星齒輪組變速器，它實現了至少九個前進速比和兩個後退速比。
