轮换
lún huàn · HSK 7
to rotate; to take turns
🔄 轮 wheel/turn + 换 swap = people turning and swapping shifts = a duty roster
轮 — car radical 车 + 仑 (phonetic)
轮 is a semantic-phonetic compound. The left side 车 (chē, 'cart/vehicle') gives the meaning, since 轮 originally referred to a wheel. The right side 仑 supplies the sound 'lún'. From 'wheel' it extended to related senses like 'rotate', 'take turns', and 'round'.
换 — hand radical 扌 + 奂 huàn (phonetic)
换 is a semantic-phonetic compound. The hand radical 扌 signals an action done with the hands, while 奂 supplies the sound huàn. The original sense of exchanging or swapping things by hand extended naturally to broader meanings like 'change' or 'replace'.