Servo motors are immensely useful tools that pack a powerful punch for their size. It is similar to AC/DC motors, except it has an additional positioning device. The attached positioning device offers useful feedback for providing extra control in a closed system loop. Even though it is small, these motors give you tremendous power and efficiency.
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| Courtesy: Innovation Electric |
Servo motors are becoming more and
more common in today’s industries where precision and control of shaft
position, rotation, torque and speed are needed. Servo motors can be found in
just about every industry on equipment such as machine tools, robotics and
anywhere there is an automated process, so having a trusted repair source for
servo motors is key to avoiding costly downtime.
If your servo motor breaks down,
you’ll need to know how to test for different issues and navigate the repair
process. In the guide below, we’ll outline how servo motor repair services
work, discuss some common servo motor problems and guide you through
troubleshooting a malfunctioning motor before deciding on professional repairs.
Common Reasons for a
Servo Motor Breakdown
If you use servo motor, you may want
to be familiar with typical reasons for motor breakdowns. Learning more about
how your servo motor works and how it may malfunction can help you troubleshoot
problems and know when to take your motor to the professionals for repairs.
Here are a few common servo motor issues and how the right repairs can resolve the
issue.
1. Faulty Power Supply
or Drive
One possibility is that the servo
motor could have an inadequate power supply or a bad drive. In this case, the
motor itself is fine, but failures of the external systems cause it to
malfunction. A faulty drive or power supply can damage a servo motor by
creating a voltage spike or irregularity in the power flowing to the motor.
Often, the winding will need to be rewound.
2. Bearing Failures
Often, what ails a servo motor is a
faulty bearing. A worn or unlubricated bearing can cause a shrill screeching
noise or whine, so if your motor is exhibiting that symptom, the bearing could
be the cause. Sometimes you can change settings and parameters to compensate
for this issue, but if that doesn’t work, you’ll probably need to get your
servo motor a bearing replacement. Be sure to do so right away — over time, a
faulty bearing can lead to total motor failure.
3. Dusty Brake
Dusty brakes can also cause a
high-pitched squeal from your servo motor. If your servo motor has a brake,
dust from the brake pads may have infiltrated the brake itself. Then the dust
can move to the bearings, soak up the oil, and lead to friction and screeching.
Even though servo motor bearings usually have shielding, dust can often find a
way to creep in and compromise them.
4. Positioning Error
A positioning error can also cause
problems for your servo motor. If this happens, the motor will stand still and
make a buzzing or chattering noise, and the output shaft will waver slightly,
even though it is at rest.
5. Setup Issue or Loss
of Parameters
Setup issues and parameter losses
can cause similar chattering issues to those caused by positioning errors. You
can check to see whether these issues are the cause of the malfunction by
running through the setup procedures for the motor and drive. If not, a
feedback issue in the motor may require repairs.
6. Electrical Failures
Setup issues and parameter losses
can cause similar chattering issues to those caused by positioning errors. You
can check to see whether these issues are the cause of the malfunction by
running through the setup procedures for the motor and drive. If not, a feedback
issue in the motor may require repairs.
7. Mechanical Binding
Faults, Brake Issues or Overload Issues
Issues with your servo motor are
mechanical binding or brake can also cause the motor to run hot. Overload
issues within the circuitry can do the same. If your motor is running hot and
you suspect these causes, get your motor repaired right away to avoid further
damage.
8. Winding Issues
If something goes wrong with a servo
motor’s winding, the motor may begin to run hot, and running hot can lead to
damage. Contamination in the winding could be causing the trouble, or an
internal short may have occurred. Either way, you’ll need to have the problem
repaired so you can get your servo motor running cool again.
9. Internal
Contamination
If contaminants such as dirt, oil,
cutting fluid and coolant get into the motor’s internal workings, they can
cause damage to the components — particularly the bearings, windings, encoder
and electrical components of the motor. The contaminants gum up the parts and
keep them from functioning as they should.
You can try to prevent contamination
by using fluids carefully and keeping the machine clean, but if dirt or fluids
begin to compromise the integrity of essential components, repairs will become
necessary.
10. Damaged Cables
If a cable has become damaged, your
servo motor may break down. Damaged cables are relatively common, and they can
also cause voltage spikes that damage the motor.
11. Overloading the
Motor
Your servo motor is likely to become
damaged if it experiences overload or runs too long. You can help prevent this
issue by giving your motor enough downtime and ensuring appropriately sized
loads.
12. Installation
Mistakes
It’s also possible that a mistake
occurred in the initial installation of your servo motor and is now causing the
motor to malfunction. Mistakes do happen, and an improperly installed servo
motor can have a host of issues. It may be coupled to a worn-out ball screw or
gearbox. It may have belts that are too tight. Or it may be slightly out of
position — and even minor errors in position can diminish a servo motor’s
performance.
13. Neglected Servo
Motor Maintenance
Neglecting to perform the required
maintenance on your servo motor can cause some of the problems outlined above.
Bearings may wear out, or oil and other fluids can build up over time and lead
to breakdowns. Scheduling basic industrial servo motor maintenance once in a
while can help avoid the need for some costly repairs.
Servo Motor
Troubleshooting
Some servo motor problems occur for
common, easy-to-fix reasons. Servo motors also typically sound an alarm to
signal something isn’t right, so you’ll often have a clear indication of
trouble even if you don’t know what the problem is. If you hear an alarm or
your servo motor doesn’t seem to be performing the way it should, you can
troubleshoot to uncover the issue.
Servo motors are complex machines. The
team will need to have expertise with electro mechanics, actuators, and
voltmeter and ohmmeter use
Courtesy: Innovation Electric
