Slip ring arrangement for an electric machine
US-2018375404-A1 · Dec 27, 2018 · US
Cooling of commutators, slip-rings or brushes e.g. by ventilating
Cooling of commutators, slip-rings or brushes e.g. by ventilating · Cooperative Patent Classification (CPC)
Electric circuits, power, telecommunications, and semiconductors.
Related technology areas
Mapped technology topics for this CPC code.
| Metric | Value |
|---|---|
| CPC code | H02K9/28 |
| Official title | Cooling of commutators, slip-rings or brushes e.g. by ventilating |
| Display label | Cooling of commutators, slip-rings or brushes e.g. by ventilating |
| Total patents | 147 |
Filing trend
Year-over-year patent counts classified under this CPC code.
Filing activity over the last five years is declining.
| Year | Patents |
|---|---|
| 2015 | 25 |
| 2016 | 14 |
| 2017 | 10 |
| 2018 | 16 |
| 2019 | 15 |
| 2020 | 10 |
| 2021 | 10 |
| 2022 | 16 |
| 2023 | 8 |
| 2024 | 12 |
| 2025 | 7 |
| 2026 | 4 |
Representative patents
Representative publications under this CPC code from precomputed stats, or recent filings when stats are unavailable.
Brushed motor
US-2018358862-A1 · Dec 13, 2018 · US
Motor structure capable of dissipating heat therein
US-10110095-B2 · Oct 23, 2018 · US
Motor with speed reduction mechanism
US-2018248448-A1 · Aug 30, 2018 · US
Alternator having an external ignition protection system
US-2018183293-A1 · Jun 28, 2018 · US
Brush assembly with bridge and leg portions with metal routing
US-10003238-B2 · Jun 19, 2018 · US
Spring post for brush card for a power tool
US-9991770-B2 · Jun 5, 2018 · US
Motor with speed reduction mechanism
US-9979261-B2 · May 22, 2018 · US
Slip-ring arrangement with spiral fan
US-2018102693-A1 · Apr 12, 2018 · US
Power tool having improved motor fan assembly
US-9923429-B2 · Mar 20, 2018 · US
Motor
US-2018076684-A1 · Mar 15, 2018 · US
Cooling structure for slip ring device
US-9793784-B2 · Oct 17, 2017 · US
Superconducting devices, such as slip-rings and homopolar motors/generators
US-2017250512-A1 · Aug 31, 2017 · US
Slip ring device
US-9712023-B2 · Jul 18, 2017 · US
Blade wheel for a rotary electric machine and rotary electric machine comprising a blade wheel
US-9689267-B2 · Jun 27, 2017 · US
Brush structure with heat dissipation member
US-9653969-B2 · May 16, 2017 · US
Cover assembly and motor
US-2017054345-A1 · Feb 23, 2017 · US
Rotary electric machine
US-9577495-B2 · Feb 21, 2017 · US
Wiper motor
US-2017047817-A1 · Feb 16, 2017 · US
Controller-integrated rotating electrical machine
US-9570962-B2 · Feb 14, 2017 · US
Frequently asked questions
Answers are generated from the same data shown on this page.
- What is CPC H02K9/28?
- CPC H02K9/28 is the Cooperative Patent Classification code for “Cooling of commutators, slip-rings or brushes e.g. by ventilating.”
- How many patents are filed under CPC H02K9/28 (Cooling of commutators, slip-rings or brushes e.g. by ventilating)?
- Our database includes 147 publications tagged with this CPC code.
- Is patent activity under CPC H02K9/28 growing?
- Publication counts under this code: 12 in 2024 vs 7 in 2025 (latest complete years).