Vacuum pump with two co-operating rotors

Pump according to one of the above claims, wherein the drive motor (25) is accommodated within the bearing/gear chamber (6).

Vacuum pump (1) comprising a pump chamber casing (5) accommodating two co-operating rotors (2, 3) which are respectively arranged on a shaft (8, 9);

• a bearing/gear chamber (6) adjacent to the pump chamber casing (5), wherein the rotor shafts (8, 9) are cantilevered and provided with a synchronisation gear (17);
• a drive motor (25) whose drive shaft (28) extends parallel to the rotor shafts (8, 9) and is provided with a drive gear (35);
• also comprising a gear stage (37) between the drive shaft (28) and one of the rotor shafts (8, 9), wherein the drive shaft (28) of the drive motor (25) is of hollow design, where one of the rotor shafts (8, 9) penetrates the hollow drive shaft (28) and where as the gear stage (37) a planet gear (41) with driven ring gear (42) and a fixed sun wheel is provided.

Pump according to one of the above claims, wherein the synchronising gear (17) has a transmission ratio differing from 1:1.

Pump according to one of the above claims, wherein the toothed gears employed in the pump are made of plastic for the purpose of reducing noise.