The assignee ranking in this dataset covers 68 companies, with the leading assignee holding 96 of the 339 records in scope — more than five times the fifth-place count of 17. The top 5 assignees combined hold 167 records, or 49.3% of the total, meaning nearly half of the field's patent activity sits with a small group of established filers. Beyond the top 10, which together hold 64.0% of records, coverage per company thins out quickly into a long tail of single- or few-filing entrants.

Yes, based on the comparable complete years: filings rose from 4 in 2021 to 9 in 2024, a +125% increase over that three-year span, with 2022 as the peak year so far at 17 filings. Figures for 2025 and 2026 are still incomplete because publication typically lags actual filing by around 18 months, so those years should not yet be read as a decline. The overall trend across 2017-2026 shows sustained activity rather than a one-off spike.

Both are captured under the same search terms in this dataset because they solve the same underlying problem — eliminating a dynamic shaft seal — using different mechanisms: magnetic coupling across a containment shell versus a motor rotor immersed directly in the pumped fluid. The IPC data shows most records falling under F04D (non-positive-displacement pump structures, 78.8% of records) with a smaller but meaningful share touching H02K (electric motors and generators, 24.2%), reflecting that pump-body and containment claims outnumber motor-specific claims in this corpus. Practitioners distinguishing the two design families in freedom-to-operate work should check both classes rather than relying on either alone.

Relative to the dominant F04D pump-body class (78.8% of 339 records), narrower classes such as F16C (shafts, bearings and couplings, 3.8%), G01R (electric and magnetic measurement, 3.2%) and F25B (refrigeration and heat pumps, 2.9%) show markedly lower record density. This does not guarantee an area is legally open, but it does suggest that claim space around bearing wear monitoring, torque transmission coupling design, and magnetic-field-based rotor sensing has fewer filed records to search against than core pump housing and impeller claims. A targeted prior-art search in those specific classes is the practical next step before drafting.

This filing, assigned to ASSOMA INC. and published in 2010, discloses a canned motor pump construction using a high-rigidity cantilever stationary shaft: a metal shaft locked at the motor rear casing compresses a ceramic shaft sleeve to form the cantilever assembly, with the sleeve providing hydraulic bearing and axial thrust support. It is a structural improvement to rotor support inside a canned motor pump rather than a claim over the canned motor pump concept generally, so it constrains specific cantilever-shaft and ceramic-sleeve arrangements rather than the whole design category. Anyone designing a similar rotor-support structure should read its claims closely, but alternative bearing and shaft-support architectures documented elsewhere in the corpus remain open.