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.

Insufficient lubrication leads to wear inside the cover

Performance: There is dryness, abnormal noise, and dust accumulation inside the A2, A3, and A5 covers.

Reason: The lubricating grease is aging and has not been replenished for a long time.

Treatment: Lubricate the interior of A2, A3, and A5 covers every 5000 hours or 1 year using Optitemp RB2, approximately 10g. After greasing, wipe off excess grease to avoid dust adsorption.

Zero point loss or Mastering abnormality

Performance: teaching point offset, program unable to reproduce, abnormal axis angle display.

Reason: Replacement of motor, toothed belt, manual release of brake, loss of encoder data, collision.

Solution: Prioritize using EMD or a dial gauge for standard Mastering. Zero position: A1 0 °, A2-90 °, A3 90 °, A4 0 °, A5 0 °, A6 0 °. After replacing the toothed belt or motor, it is necessary to re Mastering and test the program in T1 mode.

Loose or vibrating base installation

Performance: Robot shaking during operation, abnormal noise from the feet, and poor repeated positioning.

Reason: Insufficient torque of base bolts, cracking of concrete foundation, and failure of chemical anchor bolts.

Processing: The installation bases of KR 10 R1100-3 and KR 13 R900-3 use 4 M10x35-8.8 bolts with a torque of approximately 45 Nm; KR 16 R1100-3 uses 4 M16x50-12.9 bolts with a torque of approximately 195 Nm. Check after the first 100 hours and annually thereafter. The basic concrete grade must be at least C20/25, and chemical anchor bolts must be used in conjunction with the same brand.

Cable, connector, and grounding faults

Performance: The controller reports motor/data line faults, intermittent shutdowns, and abnormal shielding.

Solution: Check motor cables XD20.1/XD20.2 to XD30, and data cables XF21 to X31. The cross-sectional area of the grounding conductor is 4 mm ², with M4 ring terminals and a torque of approximately 1.2 Nm. The connector must be locked, the cable must not withstand tension, and the bending radius must be sufficient to avoid contact with sharp edges. The AIR CTR GIG version also needs to check X41, X74, X94, X30, X31, X32, PURGE, and fuse F41-F3A (3 A fast melting).

Abnormal gas path of energy supply system

Performance: Insufficient air pressure, abnormal valve action, and PURGE blockage in AIR1-AIR4.

Reason: The gas source contains water and oil, insufficient pressure, pipeline leakage, and blown fuses.

Solution: Check that the maximum pressure of AIR1-AIR4 is 7 bar, and the vacuum can reach atmospheric pressure minus 0.95 bar; PURGE has a maximum pressure of 0.3 bar, and the air needs to be oil-free, dry, and filtered, in compliance with ISO 8573-1:2010 (7:4:4). X41 power supply 24 V/3 A, maximum digital output 0.5 A, maximum short-circuit current 2 A. Valve working pressure 3-7 bar, switching frequency 10 Hz.

Planned maintenance: Block faults before they occur

The core nodes for maintaining a table are as follows:

After 100 hours: Check the torque of the fixing bolts on the installation base. KR 10/13 is 45 Nm, KR 16 is 195 Nm.

5000 hours or 1 year: lubricate the interior of A2, A3, A5 covers using Optitemp RB2 for approximately 10 g; replace the A3/A5 toothed belt (according to the model).

1 year: Check the torque of the base bolts.

20000 hours or 5 years: Replace A1 and A2 gear oil.

Before maintenance, the maintenance point must be accessible and any obstructing tools and accessories must be removed. If the oil temperature exceeds 60 ° C for a long time, the maintenance interval should be shortened and KUKA should be consulted. All accessories must use approved products, otherwise it may lead to early wear and tear.

Oil Change and Lubrication Practice

A1 gear oil: KR 16 R1100-3, first add approximately 0.36 L, with a cycle of 20000 hours or 5 years. A2 gear oil: KR 10 R1100-3 approximately 0.17 L, KR 13 R900-3 approximately 0.17 L, KR 16 R1100-3 approximately 0.25 L, with a cycle of 20000 hours or 5 years. All oil products are Optigear Synt. ALR 150. When draining oil, the robot should be in a suitable posture to ensure that the oil can be completely drained; The filling amount shall be based on the actual discharge amount. Lubricating grease: Optitemp RB2 is used inside the A2/A3/A5 covers, with a weight of approximately 10 g each time. After replacing the toothed belt, the tension and engagement should be checked and observed during operation at T1.

Installation, transportation, and cable connection

Transportation location: KR 10 R1100-3 and KR 13 R900-3 are at A1 0 °, A2-105 °, A3 158 °, A4 0 °, A5 37 °, A6 0 °; KR 16 R1100-3 is at A1 0 °, A2-120 °, A3 140 °, A4 0 °, A5 115 °, A6 0 °. Use slings or forklifts, unauthorized lifting is prohibited. The installation methods include base installation, machine frame installation, wall installation, and ceiling installation. Wall installation requires a 90 ° rotation, ceiling installation requires a 180 ° rotation, and LLA installation equipment is used. Installation base: KR 10/13 is S192, approximately 20.7 kg, with 4 M10x35-8.8 and a torque of 45 Nm; KR 16 is S220, approximately 27 kg, with 4 M16x50-12.9 and a torque of 195 Nm. Machine frame installation: KR 10/13 is approximately 0.152 kg, with 4 M10x35-8.8 and a torque of 45 Nm; KR 16 is approximately 0.514 kg, with 4 M16x50-12.9 and a torque of 195 Nm. The connecting cable lengths are 1 m, 4 m, 5 m, 7 m, 10 m, 15 m, and 25 m, with a maximum of 25 m. Interface A1 is located at the rear of the base and includes X30 motor, X31 data, X32 MEMD, X76 or X41 I/O, X74/X 94 data, AIR1-AIR4 air circuit PURGE。 Grounding conductor 4 mm ², M4 terminal, torque 1.2 Nm.

Load, foundation load, and installation method

Supplementary load: maximum 2 kg on the arm, maximum 1 kg on the rotating column/connecting rod. Flange load: KR 10 R1100-3 for operation F(a) 245 N、F(r) 223 N、M(k) 38 Nm、M(g) 23 Nm， Emergency stop F (a) 695 N, F (r) 655 N, M (k) 96 Nm, M (g) 55 Nm; KR 13 R900-3 runs 284/265/29/23, emergency stop 843/851/91/53; KR 16 R1100-3 runs 361/366/32/33, emergency stop 814/985/102/75. Basic load: KR 10 R1100-3 floor Fv normal 925 N、max 1964 N，Fh 460/1987 N，Mk 489/1917 Nm，Mr 275/530 Nm； Ceiling Fv 1120/1988 N, Fh 633/1984 N, Mk 485/1942 Nm, Mr 277/530 Nm; Wall Fv 1111/2501 N, Fh 450/1549 N, Mk 638/2064 Nm, Mr 252/544 Nm. KR 16 R1100-3 floor Fv 1485/2593 N, Fh 773/1901 N, Mk 869/2126 Nm, Mr 421/1259 Nm; Ceiling Fv 1563/2414 N, Fh 654/2485 N, Mk 812/3064 Nm, Mr 427/1255 Nm; Wall Fv 1705/2329 N, Fh 624/1708 N, Mk 1113/2439 Nm, Mr 384/1264 Nm. The maximum load is used for foundation design and must be followed.

Fault Handling Checklist

Emergency stop, power off, padlock, and power check first.

Check the alarm: motor, brake RDC、 Data cables and safety circuits.

Mechanical inspection: oil level, oil leakage, toothed belt, lubrication, base bolts.

Check parameters: load, center of gravity, inertia, installation angle, program magnification.

After replacement: Mastering, T1 testing, stop distance retest.

Record: Fault time, frequency, axle number, temperature, load, maintenance content.

The reliability of KUKA KR AGILUS-3 ultra is based on standardized maintenance. By controlling the six stages of stopping distance, base bolts, toothed belts, gear oil, lubricating grease, and zero point calibration, most on-site faults can be detected in advance. For engineers, the true idea of "replacing discontinued modules" is not to wait until they break before replacing them, but to use verifiable parameters and standard steps to turn every maintenance into a traceable quality record.