Royal Enfield 350 BULLET 1949, Руководство по техническому обслуживанию мастерской

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ROYAL ENFIELD WORKSHOP MANUAL
(iii) Fit the new field coil over the pole shoe and
place it in position inside the yoke. Take care to
ensure that the taping of the field coil is not trapped
between the pole shoe and the yoke.
(iv) Locate the pole shoe and field coil by lightly
tightening the fixing screw, insert the pole shoe
expander (see Fig. 5), open to its fullest extent and
tighten the screw. Remove the expander and give the
screw a final tightening with the wheel-operated
screwdriver. Lock the screw in position by caulking,
that is, by tapping some of the metal of the yoke into
the slot in the head of the screw.
4. (e). Armature
The testing of the armature winding requires the
use of a voltdrop test or a growler. If these are not
available, the armature should be checked by
substitution. No attempt should be made to machine
the armature core or to true a distorted armature shaft.
4 (f). Bearings
Ball bearings are fitted to both the commutator
and drive end brackets. When the bearings become
worn to such an extent that they allow side
movement of the armature shaft, they must be
replaced. To replace the ball bearing at the
commutator end proceed as follows :
(i) Remove the screw from the end of the
armature shaft and, using a caliper type extractor,
draw the bearing off the shaft.
(ii) Wipe out the bearing housing and pack the
new bearing with H.M.P. grease.
(iii) Position the bearing on the end of the shaft
and press it squarely home, applying pressure on the
inner journal of the bearing.
To replace the ball bearing at the drive end
proceed as follows :
(i) Remove the bearing retaining plate from the
drive end bracket as previously described.
(ii) Press the bearing out of the end bracket, using
a metal drift locating on the inner journal of the
bearing. Wipe out the bearing housing and pack the
new bearing with H.M.P. grease.
(iii) Position the bearing in its housing and press
it squarely home, applying pressure on the outer
journal of the bearing.
4 (g). Reassembly
In the main, the reassembly of the dynamo is a
reversal of the operation described in Subsection
4(b), bearing in mind the following points :
(i) The field coil lead fitted with the short length
of yellow tubing must be connected, together with the
eyelet of the earthed brush, to the commutator end
bracket by means of the screw provided.
(ii) The second field coil lead must be connected
to terminal "F" on the moulded cap (see Fig. 6).
(iii) The unearthed brush flexible lead must be
connected direct to terminal "D" on the moulded end
cap.
(iv) Take care to refit the cover band in its
original position and make sure that the securing
screw, when of flush-fitting pattern, does not "short"
on the brush gear.
5. Dynamo Polarity
All replacement motor cycle dynamos are
despatched from the Works suitable for immediate
use on positive earth systems. If the negative
terminal of the battery is earthed on the machine for
which the replacement dynamo is intended, it will be
necessary to re-polarize the dynamo before use to
make it suitable for negative earth.
Similarly, if a dynamo has been incorrectly
connected on the motor cycle and its polarity has
become reversed, then it must be re-polarized.
To do this, fit the dynamo to the motor cycle but
do not at this stage connect the cable to the
“D” and “F” terminals. Temporarily connect a
length` of wire to the unearthed terminal of the
battery and hold the other end of this wire in contact
with dynamo terminal "F" for a few seconds only.
This serves to re-polarize the dynamo. The temporary
connection can now be removed and the original
cables connected to "D" and "F" terminals.
The practice of closing the cut-out points to
reverse the dynamo polarity is not recommended, as
this method allows a high initial surge of current
from the battery to pass through the armature, which
can damage the windings, insulation, etc. and result
in a decreased service life of the machine.
Generally speaking, motor cycles manufactured
up to and including 1951 had the negative terminal of
the battery connected to the frame. With a few
exceptions, i.e. Miller coil ignition sets and rectifier
sets on two-stroke machines, all Royal Enfield
machines in current production have the positive
terminal earthed.
Section G2b Page 4
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