Correct Use; Unpacking; Useful Facts; Drive - IKA RW 20.n Instrucciones De Manejo

Correct use

Stirrers in the RW20.n series are suitable for stirring and mixing
liquids with low or high viscosity. They are designed for use in the
laboratory. For correct use the machine must be fixed to a stand.

Unpacking

Please unpack the machine carefully and inspect for damage. It is
important that any transit damage should be noted at the time of
unpacking. In certain circumstances it may be necessary to in-
vestigate immediately (post, rail or freight forwarder). The guaran-
tee covers: One RW20(..) stirring machine, one extension arm,
one hexagonal socket screw, one hexagon socket offset screw
key and operating instructions.

Useful facts

In buying this machine you have chosen a high quality product.
Ease of use is guaranteed with its handy shape and simple ope-
ration. The housing offers protection against ingress of liquids.
The materials used and their precise identification make recycling
possible and simple, and enables re-use of the parts. The speed
can be infinitely adjusted between 60 and 2000 rpm 50 Hz; 72
and 2400 rpm 60Hz. The machine can be operated continuously
and warms up during operation. The generously proportioned
cooling surfaces enable distribution and transference of heat to
be as even as possible. The two metre long mains lead makes it
RW201095EU
possible to work on stands - even with high glass apparatus under
vapour extraction hoods - without extension leads. The precision
stirrer shaft is designed as a hollow shaft to allow the stirrer
shanks to be inserted.

Drive

The method of operation of the motor is characteristic of the
operating behavior of the RW 20.n series units. The motor can be
infinitely adjusted via a friction wheel drive unit but is operated in
one position only. The power output, rotational speed and torque of
the motor are regarded as constant and are optimized for this
operating position. After the friction wheel drive the motor power
output is transmitted to the off-drive shaft of the stirrer via either
the first or second stage of the subsequent manually adjustable
toothed gear train.
Neglecting all losses, the power at the off-drive shaft during power
transmission (conversion) is always as great as the power output
of the motor. The gear train merely provides rpm and torque
conversion, which can be described in purely theoretical terms by
the characteristic curve plotted in Fig. 4.
Friction wheel wear is kept low by a helical clutch matched to the
gear train. The down-pressure required at the friction wheel is
adjusted by the helical clutch according to the moment acting on
the stirrer shaft. A low torque results in a low down-pressure; a
high torque results in a high down-pressure.
In order to be able to process high-viscosity media, the RW 20
DZM.n P4 does not have the second switchable reduction stage,
but features instead a planetary gear train with a gear ratio of 3.7 :
1 immediately after the first toothed gear stage. This provides a
speed range of 16 to 135 rpm at 50 Hz and 20 to 160 rpm at 60
Hz.
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