Gear device

Abstract

A speed reducer relating to an embodiment includes: a case; a reduction mechanism housed inside the case along with a lubricant, the reduction mechanism including a plurality of gears configured to rotate when acted upon by power from outside the case; a measurement chamber in communication with interior and exterior spaces of the case, the measurement chamber being shut out from ambient air outside the case; a pressure sensor configured to detect pressure inside the measurement chamber; and a control unit configured to monitor a condition of the lubricant inside the case based on a detected result by the pressure sensor.

Dependencies are inferred from the claim text.