KUKA KR 20 R1820-2 E Maintenance Troubleshooting and Replacement Practice

Motor overheating, brake failure, or wear of involute teeth

Performance: High motor temperature, difficult release of brake, A1/A2 motion shaking.

Reason: Load exceeding limit, high ambient temperature, insufficient lubrication of involute teeth, aging of O-ring, improper installation of motor.

Solution: Check the involute teeth, clean and apply PETAMO GHY 133 N, thin and continuous. O-ring coated with Drei Bond 5204HV. When installing the motor, tighten the four M8x22-8.8-A2K screws diagonally and step by step to the specified torque. Before replacing A2, the connecting rod arm must be fixed with a sling to prevent the arm from falling down after disassembling the motor.

Zero point loss or Mastering abnormality

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

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

Solution: Prioritize using EMD or a dial gauge for standard Mastering. If there are only emergency Mastering marks on site, they can be aligned according to the marks and adjusted according to the reference angles: A1-0.8 °, A2-1.2 °, A3-1.5 °, A4-1.5 °, A5-2 °, A6-2.2 °. The accuracy of emergency methods is low, and standard methods should be used for re calibration as soon as possible afterwards. After moving the axis without driving energy, it is necessary to re master it.

Connector, cable, and grounding faults

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

Solution: Check motor cable XD30, data cable XF31, and grounding conductor. The cross-sectional area of the grounding conductor is 16 mm ², and the torque of the M8 nut is about 15 Nm. The connector must be locked, and the motor connector should have a "click" sound, and the red locking ring is not visible. When the cable bending radius is fixed for laying, the motor cable should not be less than 75 mm, the control cable should not be less than 45 mm, the maximum length is 35 m, and it can be extended up to once. The cable shall not bear tensile force and shall be laid separately from the power line.

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 anchor nuts and compression bolts.

5000 hours or 1 year: Check for visible hose damage; Replace the A5 toothed belt; Check the A4 toothed belt.

10000 hours: Lubricate the A1 cable group using Optitemp RB2 for approximately 0.3 kg.

20000 hours or 5 years: Replace A1, A2, A3, A4 gear oil; Check the involute teeth of A1 and A2 and grease them.

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.

Practical points for replacing A1/A2 motors

A1 motor replacement: power-off, locking, power verification; Remove XM1 and XP1; Remove 4 M8x22-8.8-A2K pieces; Carefully remove the motor and avoid tilting it; Cover the installation port to prevent contamination. Check the involute teeth of the new motor, clean and apply PETAMO GHY 133 N; Check the O-ring and apply Drei Bond 5204HV; Insert the motor and tighten the screws diagonally; Insert the connector back, pay attention to coding and prevent accidental insertion; Finally Mastering A1 and testing at T1.

A2 motor replacement: First, fix the connecting rod arm, such as pre tightening it with a sling and a crane, to ensure that the arm will not move after removing the motor. The remaining steps are similar to A1. After installation, Master A2 and test the program in T1 mode. If there is still shaking after replacement, check the load data, brake, gearbox, and installation surface.

Start up, transportation, and storage

During transportation, it is necessary to enter the transportation position: A1 0 °, A2-140 °, A3 140 °, A4 0 °, A5 90 °, A6 0 °. Use forklift slots or M12 lifting rings, and unauthorized lifting is prohibited. During installation, a mounting base or machine frame can be used to ensure the safe transmission of foot loads. After connecting the cable, enter the installation location in WorkVisual, which defaults to the ground. If used for walls or ceilings, the tilt angle must be entered correctly, otherwise unexpected movement or overload may occur.

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, involute teeth, O-ring.

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 KR 20 R1820-2 E is based on standardized maintenance. By controlling the stopping distance, oil quality, frequency of the toothed belt, motor installation, 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.