| 摘要 |
The turbo-molecular vacuum pump has a sealed case (100) with an internal vertical support (102). The support carries a hollow rotor (103) on active magnetic bearings (111,112,115). The rotor is fitted with blades (104), and is driven by a polyphase brushless electric motor (140) with permanent magnet excitation. The supply and control circuits are in an external module (10) and are connected to the sealed casing by a cable (20). In the event of failure of supply, braking resistors (131,132,133) are automatically connected (117,118,119) across the motor to provide dynamic braking. These resistances are fitted inside the sealed casing, mounted on the support (102) for the motor bearings. |
