Help: IRB6640 constantly alarm with "34316 Motor current fault(rob1_5)"

sisrob1

Hi everyone, I am new here, and recently we have met a situation which is really weird, A 6640 gripper robot at our plant alarm with  "34316 Motor current fault"(rob1_5) first ,then axis 5 lose the zero point(other axis are fine),then we re-calibrate axis zero position, and after this it could not move even in the very slow speed, constant alarm with "34316 Motor current fault"(rob1_5), we replace the main drive/SMB cable(from controller to Axis 1 base),check the Axis 5 mechanical and motor cable ,encoder cable, connections are fine ,but after this it can move in slow speed(with 25% automatic mode), but still when we add up speed ,it run with alarm,,further more, in rest time ,we re-check/re-connect the motor/resolver cable, when we recover ,it shows very bad signs, it could not move with even 10% speed..some guys suggest to check the gearbox oil,and when we open the bolt(add oil one), some oil comes out, oil is clear,to all surprise.. after this, the robot recovery as good as normal, with 100% speed no alarm.... and in all this process, we have monitor the Axis 5 motor torque,it show some sharp waves(both in positive and negtive,middle is zero) when alarm happened, I have no ideas about the reason, and here is the pic, pleas help me on this....thanks a lot

sisrob1

I don`t know if this type torque wave was caused by encoder signal transfer disturbance？ or it was caused by mechanical collision(inside the gearbox)?
as i see the manual, when collision detection happened, there maybe exist such torque wave, but I think this was not same with our robot`s fault (above pic, it did not stop when these four sharp waves arrives, later it when sharp wave become heavier  upon the limit, the robot stop and alarm)?

fatony

Did you ever figure it out?  

fatony

Might wanna check the break board , if already not done