draft arm（牵引臂）是什么意思？音标发音+图解场景

牵引臂 /ˈdaʊnstɹiːm ˈtəʊ/ n

English: draft arm · 牵引臂

释义：One of two shafts on each side that is supported by the draft tube; the bowl is raised and lowered between them.

这个词出现在以下图解场景（1）