HBM SK12, Mounting Instructions, Page: 34 / 48

34
SK5, SK6, SK12
HBM A0842-2.0 de/en
21 Maintenance
The brushes shall only be engaged for the actual measurement. This will
greatly reduce the wear. lf dirt is accumulating on the brushes or on sliprings it
is recommended to clean them with a cleaning agent. lf the brushes are worn
out these must be replaced.
Due to the very long service life of the brushes these only need replacing after
Iong periods of operation. lf service speeds are mostly below the specified
maximum speed of rotation, the average service life of the brushes will be
8 x10
8
revolutions.
21.1 Exchange of brushes (see Fig. 8.3)
When ordering replacement brushes please quote Stock − No. 3 − 3098.0028
and type of slipring head. Replacing of brushes should be carried out as fol-
lows:
1. Separate stator as described under 4.1: 1 ... 3.
2. Loosen the three screws (16) on the name plate (8).
3. Take away f ront plate (7), ring (15), and case (3). Bolts (5) above and be-
low brush group must be unscrewed.
4. After removing the two bolts lift brush − arms (4) by using a soft pin. The
graphite brushes can be easily replaced.
5. Before reassembling sliprings should be cleaned by using a soft cloth with
benzine or trichloro − ethylene.
lf the customer cannot exchange the brushes HBM offer servicing of the unit
including exchange of brushes at the Darmstadt factory.