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If you are to repair
DC Servo
motors correctly in
most cases you must
have this type of
equipment. EDMR have
had their own
magnetising facility
since 1992.
Very soon after our
start up
we realised
that many DC Servo
motors fail due to
the nature of the
'ferrite' magnet
material.
This magnet
material naturally
loses its strength
over time. In many standard
application and
usages
sometimes it can be
due to
incorrect set-up
of drives and
systems.
In some extreme
instance the magnets
loses strength due
to the fact that the
armature has burnt
out.
If the magnet
material
deteriorates to a
reduced level it
will have a
detrimental effect
on the motor
operation and life
span,
leading to an
inevitable repair.
As a 'standard'
procedure EDMR test
and check the
magnet condition on
all DC servo motors,
referring in many
cases to our OEM
technical
specification
library to quantify
its condition, good
or bad.
The motor is
repaired and prior
to assembly the
magnet shell is re-magnetised.
On assembly the
motor is checked to
specification to
ensure it is running
correctly.
If
the motor is running
correctly all
other parts are
assembled and the
repair completed, if
the test results are
incorrect we will re-magnetise
the motor again,
completing the
process over again
In many instances,
due to
the quantity
of DC servo motor
makes and types we
have repaired, the
re-magnetising
levels are logged,
this enables us to
complete a known one
hit
re-magnetise
on a number of
different motor
makes.
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EDMR have amassed
some 40 to 50
different
magnetising fixtures
over the years, this
allows us to re-mag most
motors we receive
as standard
practice.
Even if the motor
operates close to
OEM spec, the re-magnetising
of the magnets has
shown us a vast
improvement in
running current and
Kt specification /
back emf values.
This ensures
that the motor is
operating both
within its OEM
limits and to its
optimum efficiency.
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If
we do not
have a re-magnetising
fixtures
for your particular
motor EDMR
will design and
manufacture its own.
Some time ago EDMR
were involved with a
major
sports equipment
manufacturer
OEM, they were
experiencing regular
motor failures. EDMR
were contacted as
the motor OEM's
agent, we received
and tested several
motors to find they
were are all
demagnetised.
Rather than send the
motor back to the
OEM facility, EDMR
offered its repair
and re-magnetising
facility to
resolve the problem.
EDMR constructed a
re-magnetising
fixture to allow a
complete motor to be
re-magnetised,
we could only do
this because;
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We design
our own fixtures.
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The power
of
our re-magnetising
facility.
Whilst EDMR
completed repair and re-magnetising
of
the motors it allowed
the OEM to
investigate
and
resolve the
original
problem with the
equipment.
Some motors can not
be
disassembled or
assembled
correctly without
the use of a de-magnetising
facility, the Parvex,
PML, PMI, Mavilor,
Infranor, ABB, DC
disc or pancake
motors are all
required to be de-magnetised
prior to
disassembly. If they
are not de-magnetised
before
disassembly /
assembly
damage can
occur.
It
can also be
dangerous to the
engineers working on
the motor.
Much like
conventional DC
Servo motors, various
checks and tests are
completed on
receipt, the motor
is de-magnetised.
The Disc motor is
then
disassembled,
repairs completed
and the motor
reassembled and
tested.
The motor is then re-magnetised
as an assembled
motor back to
specification again
ensuring the motor
works correctly and
to optimum
efficiency.
If the motor is
forced or prized
apart during the
repair process it
will lose
approximately
15% magnet strength,
this will result in
a loss
of torque and
increase in speed
and in some cases
the motor
overheating
may lead to
premature
failure.
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Q:
Why
re-magnetise?
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A:
To improve the
magnet strength.
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Q:
What if I
don't re-magnetise
the motor ?
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A:
If the
motor does not
run to
specification it
will have a
detrimental
effect to the
running performance, the
machine may not
operate
correctly
and in
some instances
will cause
premature motor
failure,
normally causing
the motor to
require another
repair.
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Q:
Does your
repairer of DC
servo motor have
this facility?
A:
At EDMR
this process is
included
as part of our
'standard''
service.
We ensure
your motors
are
repaired and
returned to OEM
specification,
quickly and
correctly. In
time saving you
money and effort.
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