Leybold Vacuum Products, TRIVAC A, Dual Stage, Rotary Vane ...

011:' DRAIN PORTS
WITH PLUG SCREW (81
Figure 1-1. Location of the Identification Plate, the Oil Fill Ports and the Oil Drain Ports (D30A Pump Model Shown).
lTA·2.t
SECTION 2
PRINCIPLES OF OPERATION
Vacuum pumps are used to reduce the pressure in an enclosed vessel or system. For rough and medium vacuums
(760 to 10- 3 Torr), the intake tube (1) of the rotary vane pump is connected to the vessel to be evacuated. For high or
ultrahigh vacuum (10- 3 to 10- 11 Torr), the rotary vane pump is used as a backing or roughing pump and is connected in
series and/or parallel with other types of pumps which are designed to obtain a high vacuum.
2-1 DIRECT DRIVE MECHANISM
When the motor is switched on, the motor shaft turns the pump shaft. The motor shaft and pump shaft are connected
directly through a coupling (37) and an elastic element (36) (see Figure 5-23). The elastic element (36)
absorbs shock and vibration and results in quiet operation of the pump.
2-2 PUMPING MECHANISM
2-2-1 High Vacuum Stage Pump Cylinder
The pump intake tube (1) fits into the top of the high vacuum stage pump cylinder (55). The shaft and attached
rotor (54) are mounted eccentrically in the high vacuum stage housing (52/60/55). Three rectangular vanes (53)
fit into slots in the rotor (54) (see Figures 2-1 and 2-2).
As the shaft and rotor (54d rotate, centrifugal force pushes the vanes (53) out against the pump cylinder (55)
inner surface (see Figure 2-2). The three vanes divide the cylinder into chambers 120 0 apart.
•
4
TRIVAC "A II Manual, Edition L