noun
vertical shaft; upright arm shaft
Mechanical term for a shaft oriented vertically, such as in machinery or structures. The cross-reference to 縦軸 sense 2 suggests this is a specific technical usage.
See also: 縦軸 (たてじく)
この機械の立軸は定期的に点検が必要です。
The vertical shaft of this machine needs regular inspection.
立軸のベアリングが摩耗している。
The bearing on the upright arm shaft is worn.
Often used for the abstract 'vertical axis' in graphs or coordinate systems, while 立軸 is more common for physical mechanical shafts.
Compound of 立 (standing, vertical) and 軸 (axis, shaft). The exact historical derivation is uncertain, but the meaning is transparent from the components.