Here are Some (But Certainly Not All) of the Causes of Servo Motor Failure;
1 --- The Biggest Cause of Servo Motor Failure is Heat.
When a Motor is Stalled, it Pulls Maximum Current,
and which can Overheat and Burn-Out a Motor in only a Minute or Two,
if the Operator is Not Smart Enough to Quickly Shut-Off Machine and Clear the Jam-Up!
--- Some causes are a Jammed X or Y Axis. This Occurs when Machine Pulls a Slug
Jamming Part-Sheet, or a Punch Sticks-Down causing a Jam With a Short
(Under 3 Inches) Axis Move so the Control does NOT Declare a "Excess Error" which would Shutdown Servo Drive. So, Control keeps telling the Stalled-Jammed Motor
to Move. If Operator does Not Quickly shut off Machine, you Risk Burning the Motor.
--- Sometimes the X or Y Axis Limit Switches are Not Working, or some Knuckle-Head "Adjusted" Switches to try to get a Little More Travel Length on Axis. Then, if you have a Operator Error, or Programming Error, or Control Failure that causes Axis to Hit the End of Axis-Travel, you Stall the Motor like Above, and Burn Out Motor.
--- Similar Motor-Killing Jams on Turret from;
--- Pulled-Slugs Jamming Turret to Part-Sheet,
--- Too-Tall Tool Hitting Ram,
--- Jammed Part-Sheet still Stuck to a Tool,
--- Slugs in Gears,
--- Slug Jammed between Lower Turret & Anvil Underneath
When a Jammed Turret tries to make a <3" Short 1-Station Move, there will be
No Excess Error Condition to Stop Control from Driving the Servo Motor.
Jammed Turret causes same Stalled Motor Burn Out Problem as Motor Overheats in a Couple of Minutes while Operator is Still Scratching His Head on What's Wrong......
Also, FC1000/1 & FC1000/2 & FC1250/30/1500 Machines with 20-Station Turrets
Rarely Burned-Out T-Motors because Strippit used a Small 8.67 Heater in the
T-Servo Overload-Relay to Protect Motor. When Jammed, Heater would
Quickly Heat-Up & Trip-Out similar to a Circuit-Breaker and Saving the Motor.
But, when Strippit changed to 33-Station Turrets, they Changed the Heater Size to a
Large 21.4 Heater that would Never trip-out before Motor Melted! I sometimes
change 21.4 Heater Down to about a 10.0 to 13.00 Size to help prevent this problem.
the Heater & Overload-Relay as it was Cheaper for G.E. when building Servo Drives.
Electronic Overloads NEVER Trip to Save the Motor on these Machines.
I sometime Retrofit the old Heater & Overload-Relay on to these Machines, in the Field.
Last Project I Did before Leaving Strippit was Designing this Overload-Relay Retrofit
which Strippit Added to Production FC1000/3 Machines Starting at Serial Number 200.