KUKA KR AGILUS-2 maintenance troubleshooting

KUKA KR AGILUS-2 maintenance troubleshooting

KUKA KR AGILUS-2 is a series of 6-axis articulated robots designed for small and medium-sized loads, high-speed handling, assembly, and inspection scenarios. This series includes KR 6 R700-2, KR 6 R900-2, KR 10 R900-2, KR 10 R1100-2, and corresponding EP anti-static variants. The rated load covers 6 kg and 10 kg, the maximum arm span ranges from 726 mm to 1101 mm, the repeatability accuracy can reach ± 0.02 mm, the protection level is IP65/IP67, and the noise level is below 57 dB (A). The controller can be equipped with KR C5 micro-2, KR C5 micro, KR C4 smallsize-2, and KR C4 compact. For on-site engineers, the real factors that affect equipment availability are installation fixation, toothed belt tensioning, fine fuse replacement, PURGE positive pressure maintenance, cable connection management, and common troubleshooting. Below is a set of practical maintenance and troubleshooting ideas for this series of models.

Core parameters and usage boundaries

The KR AGILUS-2 adopts a 6-axis articulated arm structure, and the body is made of light alloy casting. All motors and current carrying cables are hidden under the cover plate, and each axis is equipped with a brake. The installation position supports floors, ceilings, walls, and any angle, allowing for a tilt angle of ± 180 °. The installation hole is C246, and the chassis size is 208 mm × 208 mm. The operating environment temperature is from 0 ℃ to 45 ℃, and the storage and transportation temperature is from -40 ℃ to 60 ℃. The humidity level is 3K3, and the cleanroom level can reach Class 4 at 80% magnification.

The load must be checked for both mass and mass moment of inertia simultaneously. KR 6 R700-2 has a rated load of 6 kg, a maximum load of 6.8 kg, and a working space of 1.47 m ³; KR 6 R900-2 rated 6 kg, maximum 6.7 kg, working space 2.84 m ³; KR 10 R900-2 is rated at 10 kg, maximum 11.3 kg; KR 10 R1100-2 is rated at 10 kg, maximum 11.1 kg, with a workspace of 5.2 m ³. Install flange hole circle 31.5 mm, 7 M5 threads, strength grade 12.9, engagement depth 5.5 to 7 mm, positioning element 5 H7. The flange load during normal operation is approximately KR 6 R700-2 axial force 209 N, radial force 235 N, tilt torque 31 Nm, flange torque 17 Nm; it can reach 324 N, 297 N, 36 Nm, 24 Nm during emergency stop. During normal operation of KR 10 R1100-2, the axial force is 289 N, the radial force is 265 N, the tilt torque is 34 Nm, and the flange torque is 27 Nm; during emergency stop, the axial force is 390 N, 407 N, 54 Nm, and 42 Nm. Tool design must consider these loads, not just static weight.

The EP variant uses a special coating to keep the surface resistance of all accessible surfaces within the dissipation range, thereby improving ESD protection. The EP variant must meet the requirements of IEC 61340-5-1 and ANSI/ESD S20.20. If there are static sensitive components on site, EP variants should be preferred and ESD requirements should be checked regularly.

Safe shutdown and hazardous area control

This robot belongs to partially completed machinery and must be integrated into a complete system that complies with the EU Machinery Directive. The risk assessment, safety functions, EC conformity declaration, and CE mark must be completed by the system integrator. Dangerous areas include workspace, mechanical arm stop stroke, and external axis stop stroke. The stopping stroke is equal to the reaction stroke plus the braking stroke.

Manual mode T1 speed does not exceed 250 mm/s, T2 allows for speeds greater than 250 mm/s. T1 is used for testing, programming, and demonstration purposes; T2 is only used for testing and does not allow teaching or programming. New or modified programs must be tested under T1 first. If debugging must be carried out within the protected area, personnel and mechanical arms, including tools, should maintain a reference distance of at least 50 cm, which will be determined by risk assessment. The operator under T2 must be located outside the danger zone, and there must be no other personnel inside the protective zone.

The power-off operation must follow 5 safety steps: power-off, prevent restart, confirm no power, ground and short circuit, cover or isolate adjacent live parts. Even if the controller is turned off, some components may still carry a voltage of 50 V to 780 V for several minutes. Notify relevant personnel and hang warning signs before starting work. The motor will generate heat during operation, and protective gloves must be worn. Active implant personnel should maintain a distance of at least 300 mm from the motor and brake, applicable in both powered and powered off states. KCP or smartPAD must be clearly assigned to the corresponding robot, and disconnected smartPAD/KCP should be immediately removed from the system. External keyboard and mouse are only allowed to be used during startup or maintenance work, driver shutdown, and when no one is in the danger zone; It must be removed immediately after use. After modifying the robot, the safety level must be rechecked, all safety functions must be tested, and existing programs must be tested under T1 first.

Installation, transportation, and re-entry into operation

The installation methods include base installation and rack installation. The base installation uses a C246 base, weighing approximately 16.5 kg, with 4 chemical anchor bolts and 4 M10x35-8.8-A2K hex bolts, equipped with conical spring washers. The recommended concrete strength is C20/25, and the foundation surface should be flat and smooth. There should be no insulation layer or mortar layer between the bed board and the concrete. The rack installation uses standard rack installation components, weighing approximately 0.161 kg, with 4 M10x35-8.8-A2K hex bolts and tapered spring washers, tightened to a torque of 45 Nm. Positioning pins must be used during installation to ensure that the robot falls vertically and avoid damaging the pins.

The transportation positions are A1 0 °, A2-105 °, A3 156 °, A4 0 °, A5 39 °, A6 0 °. During transportation, rope slings are used to wrap around the pull rod and rotating column to ensure that all edges are long enough and will not damage the robot. Avoid vibration and collision during transportation, otherwise it may cause subtle damage. Before resuming operation, check whether the robot is fixed, whether there is external damage, whether the motor and brake are abnormal, whether the protective device is intact, whether the power supply system is matched, whether the grounding is reliable, whether the plug is locked, and whether there are foreign objects or loose parts.

Wall and ceiling installation requires additional Load Lifting Attachment and LLA assembly stand KR AGILUS, part number 0000-214-888. When installing on the wall, the robot is first fixed to the Load Lifting Attachment, rotated 90 °, then positioned on the wall with a forklift, and finally fixed with M10x35-8.8-A2K hex bolts with a tightening torque of 45 Nm. Ceiling installation is similar, rotated 180 °. After installation, the grounding conductor connection must be reinstalled.

Connecting cables and interfaces

Connecting cables are used to transmit power and signals between the robot controller and the robot. The standard lengths are 1 m, 4 m, 7 m, 15 m, and 25 m, with a maximum of 25 m and a maximum extension of 1 time. When the cross-section of the grounding conductor is at least 4 mm ² and the maximum cable length is 25 m. When fixed laying, the bending radius of the motor cable should not be less than 50 mm, and the control cable should not be less than 30 mm. The cable can only be installed indoors, with a temperature range of -10 ℃ to+45 ℃. Motor cables and data cables should be laid separately in metal troughs, and EMC measures should be taken if necessary.

KR C4 connection: motor cable X20 to X30, Han Jellock 30; Data cables X21 to X31, Han Q12; Grounding conductor 4 mm ², M4 ring cable terminal. KR C5 micro and KR C5 micro-2 connection: motor cables XD20.1 and XD20.2 to XD30, Han Jellock 30; Data cables XF21 to X31, Han Q12; Grounding conductor 4 mm ², M4 ring cable terminal. Interface A1 is located at the rear of the chassis, including motor cable connection X30 and data cable connection X31.

Energy supply system CTR AIR: Customer interface A1 includes MEMD connection X32, PURGE exhaust connection (IP67 option, maximum 0.3 bar, oil-free and waterless, compliant with ISO 8573-1:2010 7:4:4), AIR1 to AIR4 air circuit connection, outer diameter 4 mm, I/O cable connection X76. Customer interface A4 is located on the side of the online wrist, including X96, AIR1 to AIR4. X76 and X96 are M12, A-code, 8-pole, rated current 2 A, rated voltage 24 V. AIR1 to AIR4 have a maximum pressure of 7 bar, and vacuum to atmospheric pressure minus 0.95 bar.

Energy supply system AIR CTR GIG: Customer interface A1 includes MEMD X32, PURGE, AIR1 valve unit, fuse F41-F3A, CAT5e data cable X74, AIR2, external axis A8 XP8.1, external axis A7 XP7.1. The fuse is a 5x20mm thin fuse, fast breaking, 3A, protecting digital input and output, power supply, and valve activation. Customer interface A4 includes X41, valve unit air circuit X94、 Valve exhaust R, AIR2. The valve type is a 5/3-way solenoid valve, with a working pressure of 3 to 7 bar, a switching frequency of 10 Hz, M5 thread, and a medium of oil-free dry filtered air. The maximum filtration accuracy is 5 μ m, and the working temperature is+5 ℃ to+45 ℃. X41 digital output with 2 channels, short-circuit protection, rated 24 V DC, maximum output current of 0.5 A, maximum short-circuit current of 2 A; digital input with 4 channels, signal 0 ranging from -3 to+5 V, signal 1 ranging from 15 to 30 V, typical input current of 3 mA, typical input filtering of 0.3 ms; power supply of 24 V/3 A. If a 3A device is connected, other digital outputs or valves cannot be switched, otherwise the 3A fuse on the robot will be triggered. X74 and X94 are M12, X-encoded, and 8-pole.

PURGE options A/B/C/D are used for compressed air preparation and pressure limitation. The working pressure is fixed at 0.01 MPa (0.1 bar), the air consumption is 0.1 m ³/h, the input pressure is 0.1 to 1.2 MPa (1 to 12 bar), and the outer diameter of the air circuit connection is 4 mm. PURGE options A and C include a service unit and a pressure regulation unit, and option C has an additional robot connection M5-6. PURGE options B and D only include a pressure regulating unit, while option D has an additional robot connection. PURGE is only for cleaning purposes and is prohibited from use during operation to prevent the emission of foreign particles. The highest protection level of the component is IP54, avoiding water mist and water jets, and must not be immersed in water.

Maintenance cycle and replacement of toothed belt

Maintenance interval: Check the fastening bolts and nuts after 100 hours; Check the tightening torque of the base for 1 year; Annual review of ESD requirements for EP variants; Replace A3 and A5 toothed belts after 5000 hours or at the latest 1 year. Before maintenance, it is necessary to ensure that the maintenance point is freely accessible and remove tools and additional equipment that hinder maintenance. Robots must be secured by emergency stop and prevented from unauthorized activation.

A3 toothed belt replacement: A3 toothed belt specifications, KR 6 is 12 HTD-5M/450 HP, KR 10 is 12 HTD-5M/475 HP, target frequency is 160 ± 5 Hz. Steps: First, place the robot at A2-90 ° and A3+90 °, fix the arm with a sling, and remove the 8 M4x8-8.8 hexagonal bolts on the A3 cover plate. Loosen 2 M4x16-10.9 hex bolts, 1 M4 lock nut, and 1 M4x20-8.8 hex bolt, and remove the old strap. Install a new belt and ensure proper engagement with the toothed belt pulley. Gently tighten the M4x20-8.8 hex bolt to adjust the tension, causing the lower A3 pulley to move downwards until the pre tightening is roughly correct. At the same time, tighten two new M4x16-10.9 hex bolts until the lower pulley cannot move on its own. Measure with TSM alpha 2 frequency meter, with a sensor distance of 2 to 3 mm from the band, move the band side, and read the frequency. If the frequency does not reach 160 ± 5 Hz, fine tune the M4x20-8.8 hexagonal bolt, repeat the measurement, and tighten 2 M4x16-10.9 internal hexagonal bolts after reaching it. Remove the fixed device and run the robot to move A3 within ± 20 ° range 2 to 3 times. When controlling measurements, any position can be used without tools; If there are tools available, A3 should not be affected by gravity, such as A2-90 °, A3 0 °, or A2 0 °, A3-90 °. Measure the frequency on both sides, take the average, and if it is not within 160 ± 5 Hz, repeat the adjustment. Finally, tighten the two M4x16-10.9 hex bolts and secure the M4x20-8.8 hex bolts with M4 locking nuts. Install the cover plate, clean the foam pad, and tighten 8 M4x8-8.8 hexagonal socket bolts. After completion, calibrate A3 and run the program to check T1.

A5 toothed belt replacement: The specification of the A5 toothed belt is 6 HTD-5M/325 HP, with a target frequency of 180 ± 5 Hz. Steps: First, fix A5, remove the tool or fixing tool, or place the arm in a horizontal position with A4+90 ° or -90 °, or place the arm in a vertical position with A5 0 °. Remove the 9 M4x10-8.8 hexagonal bolts from the A5 cover plate. Loosen 2 M4x12-8.8 hex bolts and 1 M4x16-8.8 hex bolt (adjusting screw), and remove the old strap. Install a new belt and ensure proper engagement with the toothed belt pulley. Gently tighten the adjusting screw M4x20-8.8 to move the A5 pulley in the A4 direction until the preload is roughly correct. Then, lightly tighten the 2 M4x12-8.8 hex bolts to prevent the pulley from moving. Measure with a frequency meter, with a sensor distance of 2 to 3 mm from the belt, move the belt side, and read the frequency. If the frequency does not reach 180 ± 5 Hz, loosen the 2 M4x12-8.8 hexagon socket bolts, adjust the tension with adjusting screws, repeat the measurement, and tighten the 2 M4x12-8.8 hexagon socket bolts after reaching the desired frequency. Remove the tool fixing device. Operate the robot to move A5 within a range of ± 20 ° 2 to 3 times. When controlling measurements, if there are tools available, A5 should not be affected by gravity, such as keeping the arm level and A4+90 ° or -90 °; If there are no tools, any position can be used. Measure the frequency on both sides of the band, take the average, and if it is not within 180 ± 5 Hz, repeat the adjustment. Finally, tighten the two M4x12-8.8 hexagon socket bolts and secure the adjusting screws with M4 locking nuts. Install the cover plate, clean the foam pad, and tighten 9 M4x10-8.8 hexagonal socket bolts. After completion, calibrate A5 and A6, and run the program to check T1.

Replacement of fine fuses and troubleshooting of electrical faults

The fine fuse is located on interface board A1, with specifications of 3 A, 250 V, fast break, 5x20 mm. Before replacement, the controller must be turned off and prevented from restarting. Follow ESD regulations and unplug the motor cable connector. The controller equipment switch does not have grid isolation function. Before operation, the power cable must be disconnected and stored outside the line of sight and reach of the operator, with warning signs hung. Follow 5 safety steps when doing homework. When replacing, rotate the thin fuse 90 ° to unscrew the interface board, insert the new fuse and manually tighten it 90 °. No further finishing work is required after completion.

Common electrical fault troubleshooting ideas:

Robot unable to enable or emergency stop failure: Check if smartPAD/KCP is correctly connected and assigned to the corresponding robot, disconnect the device and immediately remove it from the system.

Digital output or valve not functioning: Check if X41 power supply is overloaded and if 3A fuse is tripped; If connected to a 3A device, no other outputs or valves can be switched.

IP67 protection failure: check PURGE connection, maximum 0.3 bar, no oil or water; Check if the compressed air is supplied according to ISO 8573-1:2010 7:4:4.

CAT5e communication abnormality: Check the X74/X94 X encoding connector, confirm the pins and shielding.

External axis A7/A8 no feedback: Check XP7.1 and XP8.1, only allow connection of rotary transformers.

Motor cable or data cable fault: Check the bending radius, the fixed laying of motor cables should not be less than 50 mm, and the control cables should not be less than 30 mm; check if the connectors are locked, there should be a clicking sound when the KR C5 motor connector is locked, and the red ring should not be visible and fully pushed in.

Grounding abnormality: Check the grounding conductor of 4 mm ², M4 ring cable terminal, M8 hex nut and tapered spring washer, with a tightening torque of 1.6 Nm.

Cleaning, storage, and disposal of waste

Cleaning robots must follow regulations to prevent damage. Only solvent-free, water-soluble, non flammable, and non corrosive cleaning agents should be used. Steam and refrigerants should not be used, high-pressure cleaners should not be used, compressed air should not be used to clean bearings and sealing points, and cleaning agents should not enter electrical or mechanical components. Cleaning steps: Turn off the robot, if necessary, close and lock adjacent system components, remove the cover plate that needs to be cleaned, clean the robot, thoroughly remove the cleaning agent, clean the corroded area and reapply anti rust material, install the removed safety equipment, reinstall the cover plate, only systems with normal functions and all safety functions effective can be put back into operation.

When storing, the robot must be removed, cleaned, and appropriately covered. The storage location should be dry, dust-free, avoid temperature fluctuations, wind blowing, ventilation, and condensation, avoid direct sunlight, maintain the allowed storage temperature range, and the packaging film should not be damaged. Before storage, perform visual inspection to remove foreign objects and rust, install all cover plates and check seals, seal electrical connections with suitable covers, seal hose joints with suitable plugs, cover the robot with plastic film and seal the chassis to prevent dust, and if necessary, place desiccants under the film.

When disposing of waste, classify according to materials: cast aluminum parts such as columns, arms, rods, wrists, and chassis; Copper cables and core wires; Steel gearbox, bolts, washers; Electrical components such as RDC and EDS are recycled as electrical waste; The motor is scrapped as a whole without disassembly; Plastic parts such as cover plates, cover plates, NBR shaft seals and O-rings, PU hoses, PUR cable sheaths. Auxiliary materials include Loctite 510 surface sealant, Drei Bond 1305/1342/1385/5204HV adhesive and sealant, PETAMO GHY 133 N grease, Harmonic Drive 4B No.2 grease, Sumiplex SFB No.1 grease, and Kl ü beralfa MR 3-500 UV lubricant. Waste disposal should be carried out in accordance with local regulations, and efforts should be made to classify and recycle as much as possible.