KUKA KR12 SCARA Operations Essentials

Maintenance: Ball screw spline lubrication and cable group lubrication

Maintenance table regulation: Check the torque of the four fixing screws on the installation base after 100 hours; Lubricate the ball screw spline every 1500 hours using THK AFB-LF, approximately 10 g; lubricate the cable assembly every 4000 hours or at least annually using Optitemp RB2, approximately 20 g; check the base fixing screws annually; Replace A1 gearbox oil every 20000 hours or at least every 5 years, using Optigear ALR 320 with an initial filling volume of approximately 0.37 L. An emergency stop must be triggered before maintenance to ensure that the robot does not move unexpectedly. If working on an electrified robot, it is only allowed to move in deceleration mode and can be stopped urgently at any time.

When lubricating the ball screw spline of the standard model, press and hold the A2 interface brake release button, slowly move A3 to the upper limit position until it cannot continue to move downwards, and be careful not to damage the limit block. Release the button and trigger the emergency stop, remove the old grease, evenly apply THK AFB-LF with a brush, and wear protective gloves. Then move to the lower limit position and repeat cleaning and greasing. After completion, remove excess grease and move A3/A4 to evenly distribute the grease. The CR model requires the removal of 8 M4x8-8.8 screws to move the corrugated tube down or up, apply grease, and then re fix it with a torque of approximately 2.8 Nm.

When lubricating the cable assembly, remove the A1 and A2 cable box covers: 10 M4x12-8.8 hex screws each, as well as 4 ST3.9x13 pan head self tapping screws and cable protection rings each. Apply approximately 20 g of Optitemp RB2 and then restore the cover plate. When changing the A1 oil, remove the cable box cover, remove the lower M10x1 magnetic plug, install the oil drain pipe, loosen the upper two M10x1 magnetic plugs for ventilation, collect and measure the oil drain volume. If the oil discharge is less than 70% of the specified amount, it needs to be flushed once with the discharged oil; If it is less than 50%, rinse twice and move the entire axis range at a jog speed during the rinsing process. When refueling, inject the same amount of oil from the bottom through the oil drain pipe, clean the magnetic plug, check the seal, torque the upper plug about 7.5 Nm, the lower plug about 7.5 Nm, and the cable box cover screw about 2.8 Nm. After completion, check for leaks, run the program in T1 mode, and observe any abnormalities.

Cleaning, disuse, storage, and disposal

When cleaning robots, only solvent-free and water-soluble cleaning agents are allowed. Flammable and corrosive cleaning agents are not allowed, and steam, refrigerants, or high-pressure cleaning machines are not allowed. Cleaning agents must be prevented from entering electrical and mechanical components. After cleaning, the cleaning agent should be completely removed, the corroded area should be re coated with anti-corrosion layer, and all safety devices and cover plates should be restored. When stopping the robot, first place it in the transport position, close the control cabinet and disconnect it, disconnect the peripheral connections, motor cables, data cables, and grounding wires, and then lift and remove it. The storage environment should be dry and dust-free, avoiding temperature fluctuations, wind, condensation, and direct sunlight. Clean the drying robot, inspect its appearance, remove foreign objects and corrosion, install the cover plate and check the seal, seal the electrical connections and hoses, cover with plastic film and seal the base to prevent dust, and place desiccants if necessary. When discarded, classified by material: cast aluminum components include base, arm, and connecting rod arm; Copper is used for cables and wires; Steel is used for gearboxes, ball screw splines, screws, and washers; Electronic components are treated as electrical waste, and motors are directly discarded without disassembly; Plastic ABS, PC+ABS, NBR, PU, PUR are processed according to their respective categories.

Troubleshooting Path

One of the common problems on site is accidental movement or axis sinking of the robot. Possible reasons include failure to input load data, brake defects, insufficient lubrication of ball screw splines, abnormal oil level in A1 gearbox, loose mounting base, damaged locating pins, or external collisions. The load diagram and KUKA. Load data, brake release button status, gearbox leakage, base screw torque, and locating pin should be checked. The second issue is whether the stopping distance becomes longer or stops abnormally. Should check STOP 0 times POV、 Measure the stopping distance at least annually based on factors such as elongation, load mass, axial motion superposition, and brake wear. The third issue is abnormal noise or wear of the ball screw spline. It is necessary to check the lubrication cycle, type of grease, whether the upper and lower limit positions are properly greased, and whether the bellows are damaged. The fourth issue is cable wear or abnormal signal. The bending radius, metal trunking separation, shielding grounding, connector locking, and cable group lubrication should be checked. The fifth issue is A1 oil leakage or insufficient oil volume. The magnetic plug, oil discharge amount, flushing steps, and oil filling amount should be checked. The sixth issue is condensation or abnormal temperature. Wait for the temperature of the control cabinet to adapt to the ambient temperature, and preheat before running at low temperatures. Problem seven is a safety circuit malfunction. The safety door sensor, emergency stop, T1/T2 mode, password permissions, and protective devices should be checked.