Description: Time period, starting from the first use and ending with the time when the limit state is reached.; Name: Service life
Description: Time interval from first use until the instant when a limiting state is reached ; Name: useful life
Description: translation i of a pair of gears or a multiple gear pair is the ratio of the angle speed wa (or the speed na) of the first driving wheel to that of the last driven wheel wb (or nb); Name: Transmission ratio of the transmission