What can cause sheave grooves to wear unevenly?

Improper rope equalization can lead to uneven wear in sheave grooves because it creates an imbalance in the distribution of the load among the ropes. When ropes are not equally tensioned, some ropes may bear a heavier load than others, leading to excessive friction and wear in the sheave grooves where those ropes make contact. Over time, this uneven pressure causes the grooves to wear more in areas where the load is concentrated, resulting in a misaligned or damaged sheave that can further impact the elevator's performance.

In contrast, loose fittings typically do not directly influence the wear on sheave grooves, though they can lead to other mechanical issues. Excessive lubrication may create a mess in the system and lead to slippage but does not typically cause the grooves to wear unevenly. Lack of maintenance could contribute to various issues, but it would more generally affect the entire system rather than specifically causing uneven wear in sheave grooves.