Technical Information; Description Of The Mini-Task; Turbopump Description - Varian Mini-TASK Manual De Instrucciones

DESCRIPTION OF THE MINI-TASK

The Mini-TASK pumping system consists of a
pump with an integrated controller and a forepump
and is available in three models which differ only in
the high vacuum flange.
The four models are:
− Model 969-9170 with KF 40 high vacuum
flange;
− Model 969-9171 with ISO 63 high vacuum
flange;
− Model 969-9172 with ConFlat 4.5" external di-
ameter high vacuum flange.
The following figures show the three models.

Turbopump Description

The turbopump consists of a high frequency motor
driving a turbine fitted with 10 bladed stages and 4
Macrotorr stages. The turbine rotates in an anti-
clockwise direction when viewed from the high
vacuum flange end.
The turbine is made of high-strength, light alumin-
ium alloy, and is machined from a single block of
aluminium. The turbine blades have five different
angles, from 44° to 12°, while the Macrotorr stages
are in the form of discs.
The turbine rotor is supported by permanently lu-
bricated high precision ceramic ball bearings in-
stalled on the forevacuum side of the pump.
The static blades of the stator are fabricated in
stainless steel. These are supported and accu-
rately positioned by spacer rings.
The Macrotorr stators are in the form of self-
positioning machined discs with pumping channels
and an opening restricted by the corresponding
rotor discs. These are fabricated in aluminium al-
loy
During normal operation, the motor functions with
a power feed at 54 Vac three-phase at 1250 Hz.
To reduce losses during start-up to a minimum,
the frequency increases according to a ramp with
a higher initial voltage/frequency ratio.
The external body of the pump is fitted with fins
which allow the pump itself to function with natural
convection air cooling.
A thermistor sensor is mounted near the upper
bearing to prevent the pump from overheating.
The pump is balanced after assembly with a resid-
ual vibration amplitude less than 0.01 µm.
Model 969-9170
Model 969-9171
Model 969-9172
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TECHNICAL INFORMATION

87-900-962-01(A)