【机械工程】带链条的变速齿轮

fiexible drive change-speed gear

pedestal change-speed gear of the diving key type

main pulley for secondary change-speed

clutch-controlled pedestal change-speed gear, pedestal change-speed

adjusting devices for change-speed gears for cycles

change-speed gear (variable gear, variable-speed gear)

adjustable speed motor【电】;change-speed motor【电】;variable motor【电】

change-speed gearing