Top IPC subclasses
1
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H02K
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2
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dynamo-electric machines
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2
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F04B
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2
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positive-displacement machines for liquidspumps
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3
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F04C
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2
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rotary-piston, or oscillating-piston, positive-displacement machines for liquidsrotary-piston, or os
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4
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H01F
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1
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magnetsinductancestransformersselection of materials for their magnetic properties
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