F01C 21/04
Lubrication
Official title: Lubrication (of machines or engines in general F01M)
F01C21/04 (Lubrication) appears on 140 US grants and 107 published applications in this corpus.
Search patents in F01C- Granted patents
- 140
- Published applications
- 107
- Assignees
- 81
- Inventors
- 232
- Latest grant
- 16 Jun 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 3 | 0 |
| 1977 | 3 | 0 |
| 1978 | 3 | 0 |
| 1979 | 2 | 0 |
| 1980 | 1 | 0 |
| 1981 | 0 | 0 |
| 1982 | 1 | 0 |
| 1983 | 3 | 0 |
| 1984 | 3 | 0 |
| 1985 | 7 | 0 |
| 1986 | 0 | 0 |
| 1987 | 2 | 0 |
| 1988 | 3 | 0 |
| 1989 | 1 | 0 |
| 1990 | 4 | 0 |
| 1991 | 2 | 0 |
| 1992 | 1 | 0 |
| 1993 | 2 | 0 |
| 1994 | 1 | 0 |
| 1995 | 2 | 0 |
| 1996 | 1 | 0 |
| 1997 | 0 | 0 |
| 1998 | 2 | 0 |
| 1999 | 0 | 0 |
| 2000 | 2 | 0 |
| 2001 | 3 | 0 |
| 2002 | 1 | 1 |
| 2003 | 1 | 4 |
| 2004 | 2 | 1 |
| 2005 | 1 | 5 |
| 2006 | 3 | 2 |
| 2007 | 5 | 0 |
| 2008 | 0 | 2 |
| 2009 | 0 | 8 |
| 2010 | 1 | 9 |
| 2011 | 3 | 4 |
| 2012 | 9 | 4 |
| 2013 | 5 | 5 |
| 2014 | 7 | 10 |
| 2015 | 3 | 4 |
| 2016 | 9 | 9 |
| 2017 | 4 | 4 |
| 2018 | 3 | 9 |
| 2019 | 5 | 3 |
| 2020 | 5 | 5 |
| 2021 | 5 | 8 |
| 2022 | 7 | 2 |
| 2023 | 1 | 2 |
| 2024 | 4 | 2 |
| 2025 | 2 | 3 |
| 2026 | 2 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Rotary engine lubrication system16 Jun 2026US 12,655,763 B2Compound Rotary Engines Limited
- Self-cooled rotary engine and pump12 May 2026US 12,624,656 B1
- Combined sealing piece, volumetric machine and wide fuel engine18 Nov 2025US 12,473,872 B2
- Gear pump with intermeshing gearwheels enclosed by housing with bearing journals arranged on shaft axes12 Aug 2025US 12,385,483 B2Maag Pump Systems AG
- Methods and systems for sealing rotating equipment such as expanders or compressors22 Oct 2024US 12,123,499 B2
- Rotary piston internal combustion engines1 Oct 2026US 2026/0298091 A1Compound Rotary Engines Limited
- Rotary engine lubrication system4 Sep 2025US 2025/0277452 A1Compound Rotary Engines Limited
- Combined Sealing Piece, Volumetric Machine and Wide Fuel Engine19 Jun 2025US 2025/0198363 A1
- Methods and systems for sealing rotating equipment such as expanders or compressors27 Mar 2025US 2025/0102067 A1
- Gear pump and its use24 Oct 2024US 2024/0352934 A1Maag Pump Systems AG
Most cited
By later US patents
- Sliding-blade rotary air-heat engine with isothermal compression of air99US 5,839,270 A1998
- Lubricating mechanism for scroll-type fluid displacement apparatus56US 4,547,138 ASanden Corporation · 1985
- Scroll type fluid apparatus with lubrication of rotation preventing mechanism and thrust bearing39US 4,637,786 ADaikin Industries, Ltd. · 1987
- Radial vane rotary engine38US 5,540,199 A1996
- Elliptical rotary engine34US 6,776,136 B12004