rock shaft

Noun

A shaft in a steam engine that oscillates instead of revolving.

Japanese Meaning

蒸気機関において、回転せずに振動（往復運動）する軸

The engineer inspected the rock shaft to ensure it oscillated smoothly within the steam engine's valve gear.

技師は蒸気機関のバルブ機構内で滑らかに揺動する軸を点検した。

Sense（1）

A shaft in a steam engine that oscillates instead of revolving.

rock shafts

（ plural ）