In this dataset, bearing condition monitoring patents cover systems and methods that collect vibration, acoustic emission, or other sensor data from a rotating machine and compare it against known defect signatures such as ball pass frequency. Defect frequency analysis is the mathematical technique used to derive those signatures from a bearing’s geometry and rotation speed. Most filings pair the two: a sensing or data-collection claim combined with a signal-processing or envelope-analysis claim that converts raw vibration into a diagnosable frequency spectrum. This is why G01M (testing and structure balance) and G01H (measuring vibrations and sound) both show heavy representation across the 157 records in scope.

The assignee ranking covers 83 companies across the 157 records in scope, with the leading assignee holding 17 records and the fifth-ranked holding 9. Filing is concentrated rather than evenly spread: the top five assignees together account for 41.4% of all records, and the top ten account for 59.2%. Beyond that group the ranking runs into a long tail of companies with only one or two filings each, so a competitive read of this field has to separate the small cluster of repeat filers from the much larger group of one-off entrants.

Filing peaked at 20 records in 2020 and has since declined; the clearest complete-year comparison shows a drop from 17 filings in 2021 to 2 in 2024, an 88% fall over that span. Figures for 2025 and 2026 are still incomplete because patent publication typically lags filing by about 18 months, so those final years will fill in further and should not be read as confirming a continued decline. Anyone using this trend to time a filing decision should treat 2024 as the most recent reliable data point rather than the partial years after it.