Machines or engines, in general or of positive-displacement type
Official title: MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES (of rotary-piston or oscillating-piston type F01C; of non-positive-displacement type F01D; internal-combustion engines F02B; combustion-product engine plants F02G; machines or engines, other than of positive-displacement type, for liquids F03B; positive-displacement engines driven by liquids F03C; wind motors F03D; positive-displacement machines for liquids F04B; rotary-piston, or oscillating-piston, positive-displacement machines for liquids F04C)
F01B (Machines or engines, in general or of positive-displacement type) appears on 3,309 US grants and 2,017 published applications in this corpus.
Search patents in F01B- Granted patents
- 3,309
- Published applications
- 2,017
- Assignees
- 1,064
- Inventors
- 4,217
- Latest grant
- 25 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 103 | 0 |
| 1977 | 75 | 0 |
| 1978 | 75 | 0 |
| 1979 | 63 | 0 |
| 1980 | 62 | 0 |
| 1981 | 59 | 0 |
| 1982 | 58 | 0 |
| 1983 | 49 | 0 |
| 1984 | 78 | 0 |
| 1985 | 66 | 0 |
| 1986 | 53 | 0 |
| 1987 | 61 | 0 |
| 1988 | 55 | 0 |
| 1989 | 81 | 0 |
| 1990 | 69 | 0 |
| 1991 | 58 | 0 |
| 1992 | 65 | 0 |
| 1993 | 54 | 0 |
| 1994 | 48 | 0 |
| 1995 | 38 | 0 |
| 1996 | 59 | 0 |
| 1997 | 54 | 0 |
| 1998 | 65 | 0 |
| 1999 | 60 | 0 |
| 2000 | 54 | 0 |
| 2001 | 58 | 21 |
| 2002 | 53 | 45 |
| 2003 | 61 | 50 |
| 2004 | 46 | 88 |
| 2005 | 49 | 70 |
| 2006 | 52 | 60 |
| 2007 | 44 | 65 |
| 2008 | 48 | 52 |
| 2009 | 31 | 67 |
| 2010 | 36 | 81 |
| 2011 | 33 | 68 |
| 2012 | 55 | 103 |
| 2013 | 72 | 147 |
| 2014 | 95 | 135 |
| 2015 | 94 | 119 |
| 2016 | 84 | 121 |
| 2017 | 125 | 109 |
| 2018 | 121 | 98 |
| 2019 | 114 | 118 |
| 2020 | 115 | 107 |
| 2021 | 109 | 86 |
| 2022 | 76 | 73 |
| 2023 | 66 | 33 |
| 2024 | 50 | 45 |
| 2025 | 42 | 37 |
| 2026 | 18 | 19 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Main groups
- F01B 3/00Reciprocating-piston machines or engines with cylinder axes coaxial with, or parallel or773
- F01B 9/00Reciprocating-piston machines or engines characterised by connections between pistons and main shafts756
- F01B 1/00Reciprocating-piston machines or engines characterised by number or relative disposition of cylinders492
- F01B 7/00Machines or engines with two or more pistons reciprocating within same cylinder417
- F01B 11/00Reciprocating-piston machines or engines without rotary main shaft329
- F01B 17/00Reciprocating-piston machines or engines characterised by use of uniflow principle289
- F01B 13/00Reciprocating-piston machines or engines with rotating cylinders in order to obtain the277
- F01B 29/00Machines or engines with pertinent characteristics other than those provided for in153
All 18 main groupsShow fewer
- F01B 31/00Component parts, details or accessories not provided for in, or of interest142
- F01B 19/00Positive-displacement machines or engines of flexible-wall type124
- F01B 25/00Regulating, controlling or safety means110
- F01B 23/00Adaptations of machines or engines for special use97
- F01B 15/00Reciprocating-piston machines or engines with movable cylinders other than provided for in95
- F01B 21/00Combinations of two or more machines or engines70
- F01B 5/00Reciprocating-piston machines or engines with cylinder axes arranged substantially tangentially to a32
- F01B 27/00Starting of machines or engines12
- F01B 2250/00Accessories of steam enginesIndexing code9
- F01B 2171/00Details or adaptations of steam enginesIndexing code3
Recent patents
- Hydraulic axial piston machine25 Aug 2026US 12,716,356 B2Danfoss A/S
- High-power core system25 Aug 2026US 12,719,334 B2Mainspring Energy, Inc.
- Vacuum engine11 Aug 2026US 12,704,068 B2Energie-Innovation AG
- Waissi Engine drivetrain bearing ring interface to piston base bearing pad28 Jul 2026US 12,692,813 B2
- Rotary steam engine30 Jun 2026US 12,669,056 B2
- Reciprocating mechanical devices and methods of operation1 Oct 2026US 2026/0298321 A1
- Steam Powered Electric Generator Device24 Sep 2026US 2026/0286846 A1
- Hydraulic Transformer10 Sep 2026US 2026/0266181 A1Innas B.V.
- Mechanical device for connecting rods, levers and pistons20 Aug 2026US 2026/0243334 A1
- Engine13 Aug 2026US 2026/0235068 A1Ishikawa Energy Research Co., Ltd.
Most cited
- Opposed piston internal combustion engine with inviscid layer sealing470US 9,909,492 B2Prime Group Alliance, LLC · 2018
- Power plant utilizing compressed air energy storage and saturation333US 5,491,969 AElectric Power Research Institute, Inc. · 1996
- Reciprocating machine178US 5,762,480 A1998
- External combustion slidable vane motor with air cushions149US 4,672,813 A1987
- Pipeline built-in electric power generating set139US 4,740,711 AFuji Electric Co., Ltd. · 1988