A large time constant means the opposite: that a lot of time is necessary to speed up and slow down.

加速和减速需要大量时间。

A small time constant means less time is needed to reach maximum speed, and also less time to slow down to a stop.

较小的时间常数意味着达到最大速度所需的时间更短，减速停止所需的时间也更少。