Gear and gear drive unit

Abstract

Provided are a gear in which oil film formation between the tooth surfaces of gears rotating at high speed can be effected to a sufficient degree, in which generation of pitting, abrasion, and scoring is prevented, and which helps to prevent an increase in temperature and wear to achieve an improvement in durability, and a gear drive unit. A multitude of minute concave recesses are provided at random on a tooth surface, and an average area of the recesses is set to a range of 160 to 740 μm2. Accordingly, the tooth surface can obtain a high oil film forming capacity. Thus, even under a low-viscosity/thin-lubrication condition in which the thickness of the oil film is extremely small, it is possible to achieve a long service life.

Dependencies are inferred from the claim text.