The assignee ranking is concentrated at the top, with a small group of established industrial names, including Ebara, Daikin, SKF's magnetic machinery unit, Edwards Japan, JTEKT and Siemens, holding the largest portfolios. Several of these same names show zero filings in the most recent tracked year, which suggests their positions were built earlier rather than through ongoing filing. Beyond that group, the ranking runs into a long tail of assignees with smaller, more specialised portfolios, so checking the fuller ranking table is worthwhile before assuming any one company dominates a specific sub-application.

No. Filing peaked in 2017 at 40 records for the year, and the 2022 midpoint sits at 26, confirming a flat-to-declining trend rather than growth. The most recent year in the dataset is partial and will rise somewhat as publications catch up, since publication typically lags filing by around 18 months, but the multi-year direction is clearly downward from the 2017 peak. This pattern is more consistent with a maturing field defending existing claim positions than one still in an expansion phase.

US10006489B2, assigned to Siemens, covers a method for compensating low-frequency mechanical disturbance oscillations in a rotor supported by active magnetic bearings, specifically oscillations below the rotor's rotational frequency, using a compensation control circuit that analyses, calculates and applies a counteracting force. It is a control-method claim rather than a claim on the bearing structure itself, so it constrains a specific low-frequency compensation approach rather than active magnetic bearing use generally. Designs using different disturbance-compensation logic, or targeting oscillations at or above rotational frequency, sit outside its narrowest claim scope, though a full claim chart review is needed before relying on that distinction.

The IPC composition shows F16C bearing mechanics heavily dominant at 753 of 830 records, while adjacent branches such as F16F vibration damping (31), F01D turbine integration (25), F25B refrigeration compressor applications (22), G01B measurement and sensing (18) and H02J power-grid integration (17) carry far fewer filings. These smaller counts indicate thinner prior art density in those specific integration contexts, making them reasonable areas to search before drafting new claims, particularly around touchdown-bearing wear sensing and grid-connected magnetic bearing control.

The United States leads with 281 records, followed by the European Patent Office at 203 and Japan at 151. WIPO PCT filings account for 51 records, with Canada and Austria further behind at 30 and 23 respectively. This distribution shows applicants favour direct regional filing in the US, Europe and Japan over broad PCT-first strategies, which is typical for a mechanically-focused technology with concentrated manufacturing bases in those regions.