6.2. Trouble Symptoms and Possible Causes

As shown in [table 6-1], there may be many parts as the cause of one phenomenon.

Refer to next page to determine which part is malfunction.

Table 6‑1 Trouble phenomenon and cause

Defect parts Trouble phenomenon	Reduction gear	Brake	Motor	Encoder	Backlash	Fulcrum bearing
Overload [Note 1]	○	○	○
Displacement	○		○	○
Abnormal sound occurrence	○	○	○			○
Noise in operation [Note 2]			○		○
Staggering at stop [Note 3]			○	○
Irregular twitching [Note 4]			○	○
Abnormal deviation			○	○
Free fall of an axis	○	○
Overheating	○	○	○	○		○
Incorrect action and out of control movement			○	○

[Note 1] Overload -------------------- Phenomenon occurring when a load exceeds the rated motor load.

In specific, thermal relay of circuit protector is tripped.

[Note 2] Noise in operation -------- Phenomenon which occurs vibration on operation.

[Note 3] Staggering at stop -------- Phenomenon which gives oscillating motion when the robot stops.

[Note 4] Irregular twitching -------- Phenomenon which gives sporadic twitching when the robot is not in

motion.

6.2. Trouble Symptoms and Possible Causes​