Rotary vane vacuum pump and direct coupled motor

摘要

The pump (1) and motor (2) are on a common drive shaft on which is also mounted a generator (3) to provide speed signals to the electronic control for the drive motor. The control switches off the starting capacitor when a set shaft speed is reached. The shaft speed is derived from the frequency of the generator signals, or from the voltage generated by the generator. The motor is AC driven and is in the same oil bot bath as the pump for a compact and simple layout. No moving parts are required for the shaft speed monitor.