F04C 18/22
Rotary-piston pumps specially adapted for elastic fluids: of internal-axis type with equidirectional
Official title: of internal-axis type with equidirectional movement of co-operating members at the points of engagement, or with one of the co-operating members being stationary, the inner member having more teeth or tooth equivalents than the outer member
F04C18/22 (Rotary-piston pumps specially adapted for elastic fluids: of internal-axis type with equidirectional) appears on 57 US grants and 49 published applications in this corpus.
Search patents in F04C- Granted patents
- 57
- Published applications
- 49
- Assignees
- 31
- Inventors
- 95
- Latest grant
- 7 Oct 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 1 | 0 |
| 1978 | 3 | 0 |
| 1979 | 1 | 0 |
| 1980 | 1 | 0 |
| 1981 | 1 | 0 |
| 1982 | 1 | 0 |
| 1983 | 0 | 0 |
| 1984 | 1 | 0 |
| 1985 | 0 | 0 |
| 1986 | 0 | 0 |
| 1987 | 0 | 0 |
| 1988 | 0 | 0 |
| 1989 | 0 | 0 |
| 1990 | 0 | 0 |
| 1991 | 0 | 0 |
| 1992 | 0 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 0 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 1 | 0 |
| 2001 | 3 | 0 |
| 2002 | 3 | 1 |
| 2003 | 2 | 1 |
| 2004 | 3 | 2 |
| 2005 | 0 | 0 |
| 2006 | 2 | 2 |
| 2007 | 0 | 0 |
| 2008 | 1 | 2 |
| 2009 | 1 | 0 |
| 2010 | 0 | 4 |
| 2011 | 2 | 1 |
| 2012 | 0 | 0 |
| 2013 | 1 | 0 |
| 2014 | 0 | 2 |
| 2015 | 2 | 2 |
| 2016 | 1 | 1 |
| 2017 | 1 | 4 |
| 2018 | 1 | 3 |
| 2019 | 1 | 3 |
| 2020 | 2 | 1 |
| 2021 | 3 | 6 |
| 2022 | 2 | 4 |
| 2023 | 3 | 4 |
| 2024 | 7 | 5 |
| 2025 | 5 | 0 |
| 2026 | 0 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Rotary piston compressor7 Oct 2025US 12,435,720 B2
- Non-lubricated compressor with abradable sealing element and related method for assembling it1 Jul 2025US 12,345,262 B2Atlas Copco Airpower, Naamloze Vennootschap
- Air compressor17 Jun 2025US 12,331,744 B2
- Rotary compressor27 May 2025US 12,313,073 B2LG Electronics Inc.
- Pump body assembly, fluid machinery, and heat exchange device29 Apr 2025US 12,286,972 B2Gree Electric Appliances, Inc. of Zhuhai
- Armahn Rotary Pump27 Aug 2026US 2026/0251143 A1
- Non-lubricated compressor with abradable sealing element and related method for assembling it26 Dec 2024US 2024/0426300 A1Atlas Copco Airpower, Naamloze Vennootschap
- Air compressor19 Dec 2024US 2024/0418168 A1
- Rotary piston compressor7 Nov 2024US 2024/0369061 A1
- Rotary compressor17 Oct 2024US 2024/0344518 A1LG Electronics Inc.
Most cited
By later US patents
- Rotary trochoidal compressor38US 4,018,548 ACurtiss-Wright Corporation · 1977
- Rotary piston compressor31US 4,487,561 AWankel GmbH · 1984
- Rotary compressor27US 4,118,157 AThe Bendix Corporation · 1978
- Rotary compressor with communication between chambers to provide supercharging25US 4,330,240 AThe Bendix Corporation · 1982
- Rotary piston compressor with no negative torque22US 4,218,199 ABorsig GmbH · 1980