One assignee leads the ranked field with 19 of the 57 records in scope, well ahead of the rest of the ranking of 22 companies. The top five assignees combined account for 87.7% of all records, and the top ten account for 100.0% — meaning the entire dataset is represented within the first ten ranked filers. This is a concentrated field rather than one with a long tail of small independent filers.

Filing peaked at 10 records in 2021 and fell to 1 by 2024, a 90% decline across that span. This does not necessarily mean the reliability problem is solved; it more likely reflects that the obvious mechanical fixes and lubricant formulations were already claimed by the leading filers earlier in the window. Note that 2025 and 2026 figures in any dataset like this are understated because patent publication typically lags filing by about 18 months, so a further apparent decline in those years should not be read as continued slowdown yet.

Both are documented failure modes for wind turbine gearbox bearings and gears, but they sit in different parts of the claim space in this dataset. White etching cracks relate to sub-surface material degradation often linked to electrical or lubricant-driven mechanisms, while tooth flank fracture is a structural fatigue failure tied to load spectrum and torque reversal conditions. Filings addressing either tend to cross into the C10M/C10N lubricant subclasses or the F16C shaft-and-bearing subclass depending on which mechanism they target.