Top IPC subclasses
1
|
F03D
|
18
|
Wind motors
|
2
|
H02S
|
7
|
|
3
|
F03B
|
2
|
machines or engines for liquids
|
4
|
H01L
|
2
|
Semiconductor devices; electric solid state devices not otherwise provided for
|
5
|
F16H
|
1
|
gearing
|
6
|
F22B
|
1
|
methods of steam generationsteam boilers
|
7
|
F04B
|
1
|
positive-displacement machines for liquidspumps
|
8
|
F02B
|
1
|
Internal-combustion piston engines; combustion engines in general
|