KUKA KR 700 PA maintenance troubleshooting

Before transportation, the robot must be placed in the transportation position: A1 45 °, A2-120 °, A3 150 °, A6 0 °. If the minimum transportation height is required, the A2 buffer can be removed, with A2 at -130 °. The A2 buffer must be reinstalled after transportation and before being put into operation. When transporting with a forklift, the turntable needs to be equipped with a forklift socket, and the forklift load capacity should be greater than 3500 kg. The weight of the transport frame is 212 kg, including the transport frame but without additional equipment, about 3062 kg. The transport lifting equipment should be hung at three positions: the turntable perforation, the upper arm perforation, and the rear ring head bolt of the turntable. Avoid vibration and collision during transportation, otherwise it may cause subtle damage, especially to the motor and balance weight.

Before resuming operation, check if the robot is properly secured; Is there any external damage, dents, or paint abrasion; Whether the motor and balance weight are damaged; Are there any foreign objects or loose parts; Whether the protective device is intact; Whether the power supply voltage matches the grid system; Whether the grounding wire and potential balance wire are connected correctly; Is the cable plug locked. The length of the connecting cable can be selected as 15 m, 25 m, 35 m, or 50 m, with a maximum of 50 m and a maximum extension of 1 time. When fixed laying, the bending radius of the motor cable shall not be less than 150 mm, and the data cable shall not be less than 60 mm. If it exceeds 25 m, an additional grounding wire is required, and an optional grounding wire is always required on KR C4.

Maintenance cycle and practical operation of lubrication and oil change

The KR 700 PA maintenance schedule is mainly based on 100 hours, 2500 hours, 5000 hours, 20000 hours, and 10 years. After 100 hours of operation, check the bolts and tighten them to a torque of 640 Nm. After 2500 hours or at the latest 6 months, lubricate the A3 bearings and lubricate the 4 oil nozzles at a 30 ° offset position for a total of 12 times, each time with 1.5 cm ³, using LGEP 2 grease for a total of 18 cm ³. Lubricate multiple points for 5000 hours, with approximately 10 cm ³ LGEP 2 per lubrication. Replace A1, A2, A3, A6 gearbox oil after 20000 hours or at the latest 5 years, using Optigear Synt.ALR 150. First filling amount: A1 is about 13.00 L, A2 is about 11.00 L, A3 is about 8.20 L, A6 is about 1.70 L. Replace the balance weight in 10 years and conduct internal inspection of the pressure vessel according to regulations.

When changing oil, the amount of oil discharged depends on the discharge time and oil temperature. The re added amount should be the actual discharge amount. If the discharge volume is less than 70% of the specified oil volume, the gearbox should be flushed; If it is less than 50%, it needs to be rinsed again. Move the shaft at manual speed throughout the entire shaft range during flushing. The tightening torque of A1 magnetic plug is 25 Nm; A2 and A3 are both 25 Nm; A6 lower magnetic plug is 25 Nm, and upper magnetic plug is 10 Nm. If the oil temperature exceeds 60 ℃ during operation, the maintenance cycle should be shortened. Before all maintenance operations, if tools or auxiliary devices hinder operation, they should be removed first.

Motor replacement and zero calibration

Motor replacement is a high-frequency operation in KR 700 PA maintenance. A1, A2, and A3 motors typically use four M12x30-8.8 hexagon socket bolts, which are tightened diagonally in stages to 78 Nm. A6 motor uses four M10x25-8.8 hexagon socket bolts, which are also tightened to 78 Nm. Before disassembly, the corresponding shaft must be locked: A1 prevents rotation around shaft 1, A2 uses a sling to fix the upper arm, A3 needs to fix the lower arm, and A6 needs to ensure that the tool has been removed or locked. During disassembly and assembly, it is not allowed to tilt to avoid crushing injuries, and protective gloves must be worn.

Before installing a new motor, clean the motor and gearbox of rodents and apply a small amount of Microlube GL261, but apply it completely. Check the O-ring of the motor shaft. The connection plugs XM1/XP1, XM2/XP2, XM3/XP3, XM6/XP6 must be arranged according to the diagram. After installation, the corresponding axis zero point must be calibrated. If the robot axis has been moved using a free rotating device or an electric screwdriver with torque support, all axes must be recalibrated for zero point.

The free rotation device is only allowed for emergency situations, such as rescuing trapped individuals. After use, the corresponding motor must be replaced as the motor brake may be damaged. When moving a robotic arm without driving energy, it should not be used as a routine operation.

Balance weight inspection and replacement

The KR 700 PA adopts a hydraulic pneumatic balance weight to reduce the torque around shaft 2. The system includes a diaphragm accumulator, hydraulic cylinder, pressure gauge, and safety valve, with the accumulator filled with nitrogen gas. The balance weight is approximately 95 kg and is under pressure. During inspection, the boom should be in the -90 ° position and the hydraulic oil pressure should be 138 bar; At the -45 ° position, the pressure should be 151 bar. At 20 ℃, a deviation of ± 15 bar is allowed. If the values do not match, a dedicated pressure measuring instrument should be used to measure and negotiate with KUKA.