Both sentences below include 輪 in the following compound: 車輪 (sharin: wheel). Ordinarily, I would have broken this down as car + wheel, but I’ve just discovered that 車 can also mean “wheel” or “wheeled vehicle”! Halpern breaks down 車輪 as wheel + wheel.
車輪は車軸で回転する。
Sharin wa shajiku de kaiten suru.
Wheels turn on axles.Look how many cars (車) are tucked into that short sentence. Five! Every kanji but one contains a 車!
車軸 (shajiku: axle) wheel + axle
回転 (kaiten (suru): to revolve)
to revolve + to turn車輪はぐるぐる回った。
Sharin wa guruguru mawatta.
The wheels turned around.ぐるぐる (guruguru: turning round and round)
This is onomatopoeia.
回 (mawa(ru): to revolve)
This is the kun-yomi of a kanji in the previous sentence, where it had the on-yomi of KAI.