Inspection of drive shafts A4 to A6: first at 15000 hours or 6 years, and annually thereafter. Remove the installation cover and O-ring, visually inspect for wear and bluing. Apply a tensile force of 20 N to the universal joint and check the axial and rotational clearances. If the gap is greater than 0.8 mm, the drive shaft must be stopped and replaced. The rotational clearance of connecting shaft A5 shall also not exceed 0.8 mm.
Gear oil replacement: standard robot 20000 hours or 5 years. The oil is Optigear Synt. ALR 150. Capacity: A1 10.0 L, A2 10.0 L, A3 3.5 L, A4 2.4 L, A5 2.5 L, A6 5.2 L. Oil discharge must be carried out at operating temperature, first release pressure. Measure the amount of discharged oil. If it is less than 70% of the specified amount, rinse it once with discharged oil; If it is less than 50%, rinse twice and move the entire axis range at a jog speed during the rinsing process. Torque after filling: A1 oil pipe nut 40 Nm, magnetic plug 25 Nm; A2 magnetic plug 25 Nm; A3 to A6 magnetic plug 20 Nm. The lubrication cycle of the cable assembly is 20000 hours or 5 years, using Optitemp RB2 for approximately 200 cm ³.
Balance system inspection and replacement
The balance system inspection includes pressure, leakage, bellows, joints, and bearings. When replacing ground robots, the robot should be in mechanical zero position, A2 should be movable, and firmly fixed on the ground. First, fix the piston rod between the hydraulic cylinder and the hinge joint with a clamping sleeve, and then lift the balance system with a crane. Remove 6 Allen screws and retaining plate, remove M10x35 screws, insert pin locator, use M16 puller to pull out the pin by about 25 mm, and then remove the balance system.
Remove corrosion protection before installing the new balance system and move A2 to approximately -85 °. Align the pin on the rotating column during installation, apply Drei Bond 1342, and tighten M10x35 and 6 M8x20 Allen screws to the torque. After replacement, the pressure must be checked and a functional test must be conducted. Before disposing of the balance system, pressure must be released, and only pressure free balance systems are allowed to be scrapped.
Key points for gear oil replacement
Before draining the oil, it is necessary to confirm that the gearbox is at operating temperature and release pressure first. A1 oil drainage requires pulling out the oil pipe, placing the container, loosening the magnetic screw plug to exhaust, removing the oil pipe joint, draining the oil and measuring. A2 oil discharge requires pulling out the oil pipe from the rotating column and following a similar procedure. A3 to A6 oil drainage requires removing the upper and lower magnetic plugs according to the corresponding positions, installing the oil drainage pipe, and draining the air and oil. When adding fuel, use an oil pump to add the specified amount and tighten the plug according to the torque. If the oil discharge is insufficient, it must be flushed. During flushing, move the shaft at a jog speed throughout the entire range to ensure that the old oil is drained. Check for leaks after filling and replace seals if necessary. When lubricating the cable assembly, remove the cover plate and middle plate, use a brush to evenly apply cable grease to the cables inside the base, wear protective gloves, and dispose of waste grease according to regulations.
Motor and transmission shaft replacement
A1 to A3 motor replacement: Power off and lock, remove XM/XP connector, fix connecting rod or arm with lifting device, remove 4 Allen screws, and take out the motor. Clean the motor and gearbox teeth, apply Microlube GL 261, check the O-ring, install a new seal, tighten the M12x25-8.8 or M12x30-8.8 Allen screws in diagonal order, reconnect the plug, and finally perform mastering.
A4 to A6 motor and drive shaft replacement: arm in horizontal position, wrist axis at zero position. Remove the installation cover and O-ring, remove the XM4 to XM6 and XP4 to XP6 connectors, remove 4 M10x30-8.8 Allen screws from each motor, and take out the motor and drive shaft. The transmission shaft is divided into setscrew type and O-ring type. The Setscrew type needs to be cleaned and coated with Drei Bond 1342. After tightening, loosen it back 45 degrees to allow the Setscrew to fit into the V-shaped groove. The O-ring type requires the installation of axial retainers, washers, M8x20 screws, spacers, and O-rings. The distance between the motor shaft and the drive shaft should be measured to be 16 mm, and it should automatically return to its original position after light pulling. Perform mastering and braking tests after installation.
Common troubleshooting ideas
Unexpected shutdown or safety stop: Check the emergency stop, enable switch, safety door, mode selection, external safety stop, safety configuration, and brake status.
Low or fluctuating pressure in the balance cylinder: Check the pressure gauge, accumulator, hoses, fittings, and leaks. When the ground pressure is 170 bar and there is a large deviation, consult KUKA Service.
A2 abnormal noise, sinking or vibration: Check the balance system bearings, pressure, mechanical limit and connecting rod fixation.