KUKA KR QUANTEC-2 Maintenance Troubleshooting Guide

Balance cylinder inspection and replacement

The balance cylinder is a hydraulic and pneumatic component between the turntable and the connecting rod arm, used to reduce the torque of shaft 2. During inspection, manually run A2 to -90 °, wait for 1 minute, press emergency stop, and read the pressure gauge. The pressure should be 176 bar ± 15 bar at 20 ° C. If the pressure is abnormal, a dedicated pressure gauge should be used for retesting and KUKA service should be contacted. Check whether the corrugated pipe is dirty, damaged, or leaking, and clean or replace it if necessary.

Replacing the balance cylinder is a high-risk operation. The balance cylinder weighs about 40 kg and is under pressure. Wear protective gloves and secure with slings and cranes during homework to prevent falls and accidental movements. The steps include: loosening the threaded clamp and pushing back the corrugated pipe; Move the upper arm forward by -95 ° and install it into the spacer block; Move the boom in a negative direction to secure the spacer block; Fix the balance weight and boom with a sling; Remove the cover plate and turntable bolts; Use a bolt fastener and a bolt puller to remove the bolt; Push the balance weight out of the turntable bolt; Lift it to a safe location. When installing a new balance cylinder, follow the reverse order. After completion, check the pressure and put it back into operation.

Motor replacement process

Before replacing the motor, it is necessary to comply with 5 electrical safety regulations: cutting off the power supply, locking to prevent restart, confirming no voltage, grounding and short circuiting, covering or isolating adjacent live parts. Simultaneously press the emergency stop button to prevent the robot from accidentally moving. When the motor is just stopped, the surface temperature is high and protective gloves should be worn; There is a risk of crushing during disassembly and assembly, and protective gloves should also be worn.

When replacing the motor, first remove the TORX screws from the motor cover, unplug the XM and XP plugs, unscrew the hexagonal socket bolt, and lift out the motor. Clean the teeth before installing the new motor, apply a small amount of Microlube GL 261, and check the O-ring and support ring. Install the hexagon socket screws and tighten them diagonally step by step. Connect the plug, remove the stopper, calibrate the zero point, and conduct T1 testing. The replacement steps for motors with different axes may vary slightly, but the core logic is consistent. All motors must undergo zero point calibration and T1 trial operation after replacement.

Stop distance and stop time

The stopping distance and stopping time are related to the load, program multiplier, range of action, and type of shutdown. STOP 0 immediately closes the drive and the brake is applied; STOP 1 is to brake along the trajectory and turn off the drive after reaching a standstill. KR 120 R2700-2 has a stopping distance of approximately 68.54 ° and a stopping time of approximately 1.02 seconds for A1, 32.64 ° and 0.61 seconds for A2, and 40.09 ° and 0.53 seconds for A3 under 100% operating range, 100% POV, and rated load. KR 180 R2900-2 has an A1 of approximately 61.47 ° and 1.00 seconds, an A2 of approximately 36.00 ° and 0.73 seconds, and an A3 of approximately 46.55 ° and 0.63 seconds. KR 240 R2900-2 has an A1 of approximately 57.23 ° and 1.01 seconds, an A2 of approximately 24.26 ° and 0.54 seconds, and an A3 of approximately 35.21 ° and 0.49 seconds. Regular retesting should be conducted on site based on load, speed, and brake wear, and it is recommended to check at least once a year.

Common troubleshooting ideas

On site troubleshooting should follow the principles of "safety first, power outage confirmation, record analysis, and step-by-step verification". Firstly, trigger the emergency stop, turn off the main switch and lock and tag, and confirm that the system has been discharged. Then check the controller diagnostic information, safety circuit, drive enable, RDC communication, encoder, and cable connections.

Unable to activate or emergency stop alarm: Check the enable switch, emergency stop button, safety door, light barrier, KCP/smartPAD connection. The disconnected smartPAD must be immediately removed from the system to avoid confusion. If an external keyboard or mouse is used, it must meet the requirements of driver shutdown, no one in the danger zone, and KCP/smartPAD cannot be used simultaneously.

Communication interruption or RDC failure: Check if the X20/X30, X21/X31, XF21/XF31 connectors are locked, if the cable bending radius is too small, and if the shielding and grounding are good.

Zero point loss: replace the motor RDC、 After the encoder battery or collision occurs, it is necessary to recalibrate the zero point. After calibration, test under T1 first, and then gradually restore automatic operation.

Abnormal balance cylinder pressure: Check the pressure gauge, leakage points, bellows, and seals. If the pressure is below the allowable range, KUKA service should be contacted and unauthorized pressurization is not allowed.