KUKA KR AGILUS-3 ultra maintenance troubleshooting

KUKA KR AGILUS-3 ultra maintenance troubleshooting

KUKA KR AGILUS-3 ultra is a small high-speed six axis articulated arm robot, covering three main models: KR 10 R1100-3, KR 13 R900-3, and KR 16 R1100-3. They are usually paired with KR C5 micro-2 controllers, with a protection level of IP67, repeat positioning accuracy of about ± 0.02 mm to ± 0.03 mm, weight ranging from about 57 kg to 89 kg, and rated load ranging from 10 kg to 16 kg. For on-site engineers, what is truly valuable is not remembering parameters, but establishing a maintenance logic of "safety first, diagnosis later, replacement later, and final calibration". Below, we will discuss several aspects including stopping distance, common faults, planned maintenance, oil change, toothed belt, installation, and cables.

First, check the safety and shutdown distance

The danger zone of KR AGILUS-3 ultra is composed of both workspace and stopping distance. The stopping distance is not a fixed value, it is affected by program magnification, load, extension distance, and brake wear. Taking STOP 0 as an example, the stopping distance of KR 10 R1100-3 at A1 is about 51.26 °, A2 is about 14.18 °, and A3 is about 35.57 °; The corresponding stop times are approximately 0.44 s, 0.12 s, and 0.23 s. The A1 of KR 13 R900-3 is about 48.81 °, A2 is about 13.89 °, and A3 is about 29.74 °. The A1 of KR 16 R1100-3 is about 24.49 °, A2 is about 22.40 °, and A3 is about 33.36 °. STOP 1 varies with program magnification and mass, and the corresponding curve needs to be checked. If it is found on site that the robot's sliding after braking has significantly increased, there is abnormal braking noise, and there is repeated positioning drift, the first reaction should not be to change the program, but to check the brake wear and stopping distance. It is recommended to retest the stopping distance at least once a year, especially under frequent triggering of STOP 0, high cycle, and high load conditions.

Strict habits must be formed for safe operation: switch T1 before entering the danger zone, press emergency stop, cut off the main switch and lock it; If it is necessary to debug in the powered on state, it can only run at low speed T1 and ensure emergency stop at any time. After the robot loses power, the power components may still be charged for a short period of time. Wait for at least 5 minutes and verify the power. The motor and brake will generate electromagnetic fields, and personnel wearing active implants such as pacemakers should maintain a distance of at least 300 mm. The surface temperature of the motor is high, and protective gloves must be worn when replacing or inspecting it. When it comes to electrical operations, strictly follow the five safety rules: power off, prevent accidental restart, confirm no power, ground short circuit, and block adjacent live parts; After the work is completed, restore in reverse order.

Common faults and troubleshooting ideas

The stopping distance increases or the braking is abnormal

Performance: Stop position deviation, increased collision risk, and abnormal braking sound in automatic mode.

Reason: Brake wear, incorrect input of load data, high program magnification, external axis stacking motion.

Processing: Verify the load data in the controller, including mass, center of gravity Lx/Ly/Lz, moment of inertia Ix/Iy/Iz, and A/B/C directions; Verify with KUKA Load; Check the brake system; Retest the stopping distance. If there is a change in load or supplementary load, it must be re inputted, not based solely on experience.

Slip, noise or positioning error of the toothed belt

Performance: There is abnormal noise, increased reverse clearance, and positioning drift when moving A3 or A5.

Reason: Aging of the toothed belt, insufficient tension, and poor engagement of the pulley.

Solution: Replace according to the maintenance schedule. It is recommended to replace the A3 and A5 toothed belts of KR 10 R1100-3 after 5000 hours or 1 year; A3 and A5 of KR 13 R900-3 should also be replaced after 5000 hours or 1 year; Replace the A5 toothed belt of KR 16 R1100-3 after 5000 hours or 1 year. Check the engagement after replacement to avoid tilting installation.

Gearbox oil leakage or abnormal oil level

Performance: There are oil stains near A1 and A2, and the temperature is too high during operation.

Reason: seal aging, screw plug not tightened according to torque, incorrect oil quantity, installation angle leading to incomplete oil discharge.

Solution: Replace the gear oil according to the shaft. The recommended oil is Optigear Synt. ALR 150. The initial filling amount of A2 for KR 10 R1100-3 is about 0.17 L; A2 for KR 13 R900-3 is about 0.17 L; A2 for KR 16 R1100-3 is about 0.25 L, and A1 is about 0.36 L. The replacement cycle is generally 20000 hours or 5 years. Oil discharge must be carried out at operating temperature and the discharge volume measured. If the discharge volume is too low, it should be flushed according to the specifications. The filling amount shall be based on the actual discharge amount. Be aware that the oil chamber may be under pressure, and release the pressure before opening the drain plug.