H01F 38/18
Rotary transformers
H01F38/18 (Rotary transformers) appears on 282 US grants and 283 published applications in this corpus.
Search patents in H01F- Granted patents
- 282
- Published applications
- 283
- Assignees
- 200
- Inventors
- 642
- Latest grant
- 29 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 1 | 0 |
| 1978 | 2 | 0 |
| 1979 | 0 | 0 |
| 1980 | 3 | 0 |
| 1981 | 1 | 0 |
| 1982 | 4 | 0 |
| 1983 | 2 | 0 |
| 1984 | 0 | 0 |
| 1985 | 2 | 0 |
| 1986 | 2 | 0 |
| 1987 | 1 | 0 |
| 1988 | 1 | 0 |
| 1989 | 4 | 0 |
| 1990 | 4 | 0 |
| 1991 | 4 | 0 |
| 1992 | 2 | 0 |
| 1993 | 2 | 0 |
| 1994 | 3 | 0 |
| 1995 | 3 | 0 |
| 1996 | 5 | 0 |
| 1997 | 4 | 0 |
| 1998 | 8 | 0 |
| 1999 | 4 | 0 |
| 2000 | 2 | 0 |
| 2001 | 3 | 0 |
| 2002 | 10 | 9 |
| 2003 | 4 | 6 |
| 2004 | 4 | 5 |
| 2005 | 7 | 3 |
| 2006 | 2 | 3 |
| 2007 | 3 | 10 |
| 2008 | 1 | 5 |
| 2009 | 4 | 13 |
| 2010 | 7 | 5 |
| 2011 | 7 | 16 |
| 2012 | 9 | 12 |
| 2013 | 8 | 15 |
| 2014 | 8 | 16 |
| 2015 | 13 | 20 |
| 2016 | 18 | 14 |
| 2017 | 18 | 17 |
| 2018 | 15 | 6 |
| 2019 | 11 | 10 |
| 2020 | 8 | 6 |
| 2021 | 4 | 15 |
| 2022 | 12 | 16 |
| 2023 | 12 | 9 |
| 2024 | 14 | 15 |
| 2025 | 7 | 23 |
| 2026 | 8 | 14 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Rotor for an externally excited synchronous machine29 Sep 2026US 12,749,951 B2Mahle International GmbH
- Inductive power couplings for pool and spa equipment26 May 2026US 12,640,590 B2Hayward Industries, Inc.
- Electrically excited synchronous machine26 May 2026US 12,640,614 B2Mahle International GmbH
- Electromagnetic power transfer system5 May 2026US 12,620,845 B2
- Synchronous machine5 May 2026US 12,620,861 B2Mahle International GmbH
- Wireless exciter system, a motor and a mobility device having the same1 Oct 2026US 2026/0302895 A1Chalmers University of Technology
- Current transmission device for externally excited synchronous machines having segmented ferrite cores24 Sep 2026US 2026/0291300 A1ZF Friedrichshafen AG
- Rotary system having a resolver13 Aug 2026US 2026/0237556 A1Schaeffler Technologies AG & Co. KG
- Electric power transmission device and motor apparatus13 Aug 2026US 2026/0238089 A1TDK Corporation
- Power Transfer Control Method in a Rotary Transformer23 Jul 2026US 2026/0213067 A1Irp Nexus Group Ltd.
Most cited
By later US patents
- Electric machine with a transformer having a rotating component117US 5,519,275 AColeman Powermate, Inc. · 1996
- Contactless power transfer system115US 7,197,113 B1General Electric Company · 2007
- Device for combined transmission of energy and electric signals91US 5,814,900 AUlrich Schwan · 1998
- High frequency matrix transformer power converter module68US 4,942,353 AFMTT, Inc. · 1990
- Signal transmission device54US 4,837,556 AKabushiki Kaisha Nihon Denzai Kogyo Kenkyusho · 1989