H01F 27/12
Oil cooling
H01F27/12 (Oil cooling) appears on 385 US grants and 438 published applications in this corpus.
Search patents in H01F- Granted patents
- 385
- Published applications
- 438
- Assignees
- 179
- Inventors
- 942
- Latest grant
- 15 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 3 | 0 |
| 1977 | 2 | 0 |
| 1978 | 2 | 0 |
| 1979 | 1 | 0 |
| 1980 | 0 | 0 |
| 1981 | 2 | 0 |
| 1982 | 1 | 0 |
| 1983 | 1 | 0 |
| 1984 | 6 | 0 |
| 1985 | 4 | 0 |
| 1986 | 1 | 0 |
| 1987 | 4 | 0 |
| 1988 | 3 | 0 |
| 1989 | 3 | 0 |
| 1990 | 2 | 0 |
| 1991 | 1 | 0 |
| 1992 | 3 | 0 |
| 1993 | 2 | 0 |
| 1994 | 2 | 0 |
| 1995 | 1 | 0 |
| 1996 | 0 | 0 |
| 1997 | 1 | 0 |
| 1998 | 4 | 0 |
| 1999 | 5 | 0 |
| 2000 | 2 | 0 |
| 2001 | 2 | 0 |
| 2002 | 5 | 6 |
| 2003 | 6 | 5 |
| 2004 | 6 | 8 |
| 2005 | 6 | 8 |
| 2006 | 2 | 3 |
| 2007 | 4 | 7 |
| 2008 | 5 | 14 |
| 2009 | 4 | 8 |
| 2010 | 12 | 12 |
| 2011 | 12 | 23 |
| 2012 | 14 | 15 |
| 2013 | 12 | 15 |
| 2014 | 11 | 20 |
| 2015 | 13 | 21 |
| 2016 | 7 | 23 |
| 2017 | 22 | 27 |
| 2018 | 19 | 23 |
| 2019 | 16 | 26 |
| 2020 | 29 | 28 |
| 2021 | 16 | 40 |
| 2022 | 19 | 20 |
| 2023 | 28 | 27 |
| 2024 | 25 | 28 |
| 2025 | 19 | 14 |
| 2026 | 15 | 17 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Intelligent drying device for transformer15 Sep 2026US 12,734,478 B2Fortune Electric Co., Ltd.
- Power transformer16 Jun 2026US 12,658,359 B2Hitachi Energy Ltd
- Subsea control and power enclosure9 Jun 2026US 12,651,688 B2Siemens Energy, Inc.
- Technologies for preventing the explosion of electrical transformers9 Jun 2026US 12,651,698 B2Philippe Magnier LLC
- Electrically excited synchronous machine26 May 2026US 12,640,614 B2Mahle International GmbH
- Method and system for diagnosing leakage of insulating oil24 Sep 2026US 2026/0287457 A1Fortune Electric Co., Ltd.
- Air-cell rupture diagnosis method and system24 Sep 2026US 2026/0290683 A1Fortune Electric Co., Ltd.
- Electric arrangement, panel and heat exchanger27 Aug 2026US 2026/0251405 A1Hitachi Energy Ltd
- Cooling arrangement and method for cooling at least one oil-to-air external heat exchanger6 Aug 2026US 2026/0227131 A1Hitachi Energy Ltd
- Device, system, and method for oil-containing electrical power devices or transmission devices16 Jul 2026US 2026/0202352 A1EON Corporation
Most cited
By later US patents
- Dielectric fluid for use in power distribution equipment72US 5,766,517 ACooper Industries, Inc. · 1998
- Intelligent analysis system and method for fluid-filled electrical equipment54US 6,446,027 B1General Electric Company · 2002
- Process for the extraction of oil or polychlorinated biphenyl from electrical parts through the use of solvents and for distillation of the solvents49US 4,879,004 AMicafil AG · 1989
- Gas-insulated stationary induction electrical apparatus47US 4,904,972 AHitachi, Ltd. · 1990
- Apparatus for continually upgrading transformer dielectric liquid46US 4,437,082 AWestinghouse Electric Corp. · 1984