The Edwards E2M8 pumps are oil-sealed and designed for reliable, long-term operation in both laboratory and industrial environments. The pumps are free-standing units. The drive is provided through a flexible coupling by a single-phase or three-phase motor.
The motors are totally enclosed and are cooled by the motor-cooling fan which directs air along the motor fins.
The single-phase motors have either an automatic or manual reset thermal overload device. When the motor is too hot, the thermal overload device switches off the pump. If the thermal overload device has an automatic reset, when the pump cools down, the device resets and the pump will restart.
A rotary vane pump can be described as a positive-displacement pump that is comprised of vanes mounted to a rotor that rotates inside of an enclosure. In some instances these vanes can be of varying length and tensioned to maintain contact with the walls as the pump rotates.
The simplest rotary vane pump is a circular rotor revolving inside of a larger round enclosure. The centers of these two bands are offset, inducing eccentricity. Vanes are allowed to slide in and out of the rotor and seal on all edges, making vane chambers that do the pumping work. On the intake side of the pump, the vane chambers are increasing in volume. These increasing volume vane chambers are filled with fluid forced in by the inlet pressure. Inlet pressure level is actually the pressure level from the system being pumped, frequently just the atmosphere. On the exhaust side of the pump, the vane chambers are decreasing in volume, forcing fluid out of the pump. The activity of the vane drives out the same volume of fluid with each rotation. Multistage rotary vane vacuum pumps can reach pressures levels as low as 103 mbar (0.1 Pa).Visit the rotary vane pump wiki page for more information.