differential gear
noun [ C ] engineering specialized uk/ˌdɪf.ə ˈren.ʃəl ˈɡɪər/ us/ˌdɪf.ə ˈren.ʃəl ˈɡɪr/
差速齿轮
a device fitted to the axle of a vehicle that allows the wheels to turn at different rates when going around a corner
See also: differential noungear noun (ENGINE PART)