A claw pump consists of two rotors. They turn in opposite directions in a housing, without contact, having very close clearances. They are synchronized via a precision gear. As the claw moves over the suction connection, the air is sucked into the chamber.

As the rotors revolve, the air moves from the suction side to the exhaust side. Then it is compressed by the reduction of the volume between the rotors until the lower rotor uncovers the discharge channel. Afterwards the compressed air is discharged via the exhaust connection.