MG MGB User Manual

THE
ELECTRICAL
SYSTEM
'
'
N
(212°
F.)
for
two
hours,
then
allowing it
to
cool
before
removing
the bearing
bush.
The
ball bearing is
renewed
as
follows.
Drill
out
the
rivets
which
secure
the bearing
retaining
plate
to
the end
bracket
and
remove
the plate.
Press
the bearing
out
of the end
bracket
and
remove
the
corrugated
washer,
felt
washer,
and oil-retaining
washer.
Before
■tting
the
replacement
bearing
see
that
it is
clean
and pack
it
with
high-melting-point
grease.
Place
the oil-retaining
washer,
felt
washer,
and
corrugated
washer
in
the bearing
housing in
the
end bracket.
Press
the
bearing
into
the housing.
The
outer
bearing
journal
is
a
light
push-■t
in
the bearing
housing.
Refit the
bearing retaining
plate,
using
rivets
having
the
same
dimensions
as
those
originally fitted.
NOTE—When ■tting
a
drive
end bracket
to
the
armature
shaft the inner
journal
of the bearing
MUST
be
supported
by
a
mild-steel
tube-do
not
use
the
drive end
bracket.
Reassembling
The
reassembly
of the
dynamo is
a
reversal
of the
dismantling
sequence.
If the
end
bracket
has
been
removed
from the
armature
in
dismantling,
press
the bearing
end
bracket
onto
the
armature
shaft, taking
care
to
avoid damaging
the end
plate
and
armature
winding.
When
assembling the
commutator
end bracket
the
brushes
must
■rst be
held clear
of the
commutator
by
partially
withdrawing
them
from their
boxes until
each brush
is
trapped
in position
by
the side
pressure
of
its
spring.
The
brushes
can
be
released
onto
the
commutator
by
a
small
screwdriver
or
similar tool
when the
N
m
\\\\\\\\\\\\\
:9
gr
.7
\W
/
[fill/II]
(9A
3
Fig.
NA
The method of
pressingin the
commutator
end
bracket bush
is
shown in
this illustration
1.
Shouldered
mandrel.
2.
Hand
press.
MGB.
Issue
6. 5335
3. Bea'ring
bush.
4.
Support
block.
1660‘!
Fig. N.5
Expanding
the pole-shoesin the
yoke
end bracket
is
assembled
to
within about
1/2
in.
(13
mm.)
of
the yoke.
Before closing the
gap
between
the end bracket
and the yoke
see
that the
springs
are
in
correct contact
with
the
brushes.
Add
a
few
drops of oil through
the hole
in
the
armature
end
cover.
Refitting
Reverse
the removal procedure,
noting
that
on
later models
plain washers
are
■tted under the heads
of the
two
upper
fixing bolts.
Section N.5
CONTROL
BOX MODEL
R3340
General description
The RB340
control box
operates
on
the
current-voltage
system
of
dynamo
output
regulation. Three
units
are
housed
in
the control
box:
two separate
vibrating
armature-
type
single-contact regulators and
a
cut-out
relay.
One
regulator
is responsive
to
changes
in
current
and the
other
to
changes
in
voltage.
The
voltage
regulator and
cut-out
relay
are
temperature-compensated
to
allow
for
operating
changes
in
the
circuit resistance
and for climatic
variations in
battery
voltage.
The
effect of
temperature
■uctuation
on
control
box
settings
is
further minimized by the
use
of
a
swamp
resistor
connected
in
series
with
the shunt coils
of the
voltage
regulator and
cut-out
relay.
For adjustment
purposes
toothed
cams
are
carried
On
the
front limb
of each
magnet
frame
to
enable
voltage and
current
settings
to
be
made with
a
special tool
(see
Fig.
N.7).
‘
The
control box
settings
are
accurately adjusted
during
manufacture and
the
cover
should
not
be
removed
unnecessarily.
N.7

MG MGB Specifications

General

Brand	MG
Model	MGB
Category	Automobile
Language	English