17
Technical Information
Pump Description
Figure 3 Model 969-8935, Model 969-8936, Model 969-8937, Model 969-8938
Pump Description
The pump consists of a high frequency motor driving a turbine fitted
with 8 bladed stages and 4 Macrotorr stages. The turbine rotates in
an anticlockwise direction when viewed from the high vacuum flange
end. The envelope is made of STT. The turbine is made of high-
strength aluminium alloy, machined from a single block.
Proceeding from the high vacuum to the for vacuum region, the
turbine stages sequence is:
210/276
1st stage with a blade angle of 40°,
2nd stage with a blade angle of 34°,
3rd stage with a blade angle of 28°,
4th and 5th stages with a blade angle of 24°,
6th stage with a blade angle of 20°,
7th and 8th stages with a blade angle of 16°.
TV 551/701 SEM Navigator User Manual /
87-900-958-01(G)