KUKA KR60 SCARA CS Maintenance Guide

KUKA KR60 SCARA CS Maintenance Guide

Product positioning and system composition

KUKA KR 60 SCARA CS is a four axis SCARA SCARA robot launched by KUKA for high-speed handling, assembly, and picking and placing scenarios. Its representative model is KR 60 R1200 Z400 CS. The entire robot system consists of a manipulator, KR CS Box-2 controller, smartPAD touch teach pendant, power and data cables, and KUKA. ControlStudio system software.

From the technical data, the maximum working radius of this model is 1200 mm, the rated load is 20 kg, the maximum load is 60 kg, the repeat positioning accuracy is ± 0.05 mm in the XY direction and ± 0.02 mm in the Z direction, the overall weight is about 120 kg, the protection level is IP54, and the single cycle time is 0.80 s. Axis 3 has a Z-axis linear travel (-400 mm to 0 mm), a travel speed of 0.75 m/s, and the angular velocities of axis 1/2/4 reach 230 °/s, 260 °/s, and 690 °/s, respectively, belonging to a typical high-speed SCARA configuration. Understanding these parameters is the foundation for developing maintenance strategies in the future - high tempo, high acceleration operation will directly accelerate the wear of toothed belts, ball splines, and gearboxes.

Maintenance Overview: Maintenance Cycle Divided by Operating Hours

The maintenance system of this model provides a clear cycle table in the assembly manual, which engineers can use to establish a point inspection plan:

100 hours (only once, after debugging or re debugging): Check the tightening torque of the 4 fixing bolts on the installation base. The base must be made of steel, with a thickness of not less than 30 mm and a flatness of not more than 0.4 mm.

1500 hours: Add lubricating grease to the Ball Screw Spline using THK AFB-LF, with a dosage of approximately 18g (order number 0000-342-918).

4000 hours or at the latest 1 year: replace A3 and A4 toothed belts (this work must be completed by qualified personnel authorized by KUKA); Simultaneously apply Optitemp RB2 cable grease (approximately 20 g, order number 0000-101-294) to the cable assembly.

1 year: Replace the battery unit (order number 0000-439-232).

20000 hours or at the latest 5 years: Replace the gear oil of A1 and A2 reducers with Optigear Synt. ALR 150 1000L (order number 0000-338-212), with an initial installation quantity of 0.47 L for A1 and 0.21 L for A2.

It should be emphasized that the above cycle is based on the standard operating conditions specified in the manual. If the robot operates near the temperature limit for a long time, is in a corrosive environment, approaches the performance limit for a long time (such as a certain axis running at high speed for a long time), has a high single axis load rate, or has a single repetitive motion trajectory, it is necessary to contact KUKA in advance to confirm and shorten the maintenance interval. In addition, the temperature of each axis motor should not exceed 368 K (+95 ° C) during long-term operation, otherwise overheating of the motor will significantly shorten the lifespan of the entire machine.

Key points for lubrication operation of ball spline

Ball spline lubrication is divided into two stations: upper limit and lower limit. Before operation, it is necessary to ensure that the driver is powered off and the emergency stop device is activated to prevent accidental action.

Upper limit grease injection: Press and hold the brake release button on interface A2, slowly move A3 to the upper limit position (be careful not to damage the limit block), and activate the emergency stop after releasing the button. Remove the 4 M4x16-8.8 screws on the small cover plate of the top cover, use a manual grease gun with a conical nozzle to evenly inject THK AFB-LF into the lubricating grease pipe of the ball screw until it is close to overflowing, then reset and dispose of the waste grease according to local regulations.

Apply grease to the lower limit position: Using the same method, move A3 to the lower limit position and remove the old grease from the lower part of the spline. Wear protective gloves and use a brush to evenly apply THK AFB-LF to the surface of the ball spline and guide shaft. Then, move A3/A4 back and forth to evenly distribute the grease and wipe off excess grease.

Replacement and tension verification of toothed belt A3/A4

The replacement of the toothed belt is the most critical high-level maintenance project for this model, involving the disassembly of the top cover and cable assembly. Before starting the homework, make sure to align the ball spline with the safety stopper below to prevent the spline from accidentally falling during disassembly and assembly; Simultaneously follow the five step safety regulations of power-off, locking, electricity verification, grounding, and shielding.

When disassembling the top cover, loosen the 7 M4 × 12-8.8 screws on the top cover and the 12 M4 × 60-8.8 screws on both sides of the arm in sequence. Slightly tilt the top cover to detach it from interface A2 and carefully remove it, avoiding touching the ball screw throughout the process. Then remove the cable fixing plate (4 M4x8-8.8 screws) and remove the cable assembly. It is strictly prohibited to forcefully pull the cable.

The replacement of A3 toothed belt is relatively direct: loosen the 4 M5x20-12.9 screws on the motor flange to remove the A3 motor and toothed belt assembly as a whole, and ensure that the toothed belt is correctly engaged with the pulley during installation. The A4 toothed belt requires additional disassembly of 2 M5 × 20-12.9 screws on the spline triangle block, 4 M6x25-12.9 screws on the bearing support plate, and the guide shaft fixing screw, and the old belt needs to be removed from the gap between the bearing support plate and the support frame.

Tension verification is the core link that determines the quality of replacement. Replace 4 new M5x20-12.9 screws with conical spring washers but do not tighten them yet. Gently tighten the M5 × 40 tension screw, use a frequency meter (TSM alpha 2, order number 0071-053-386) to move the belt and place the sensor 2-3 mm away from the vibration belt to read. Repeat the measurement three times and take the average. The reference frequency is:

A3（860-5GT-12 HSN）：47 Hz … 50 Hz

A4（1080-5GT-10 HSN）：34.8 Hz … 37 Hz

If the mean does not match, fine tune the tension screw and retest; The fluctuation of tension is a normal phenomenon, and a deviation within ± 30% of the reference value is acceptable. Otherwise, it needs to be readjusted. After confirmation, gradually tighten the 4 M5x20-12.9 screws in diagonal order to 9 Nm, and then tighten the M5 locking nut on the tension screw. When reinstalling the top cover, the torque of the 7 M4x12 screws at the A2 interface is 0.8 Nm, and the torque of the 12 M4x60 screws on both sides of the arm is 1.6 Nm. After completion, the program must be tested in T1 manual deceleration mode and the corresponding axis must be recalibrated.

Battery unit and gear oil replacement

Battery replacement is carried out at interface A1: remove the 4 M3x10-8.8 screws to remove the interface battery unit, connect the spare plug to the new battery, unplug the old battery plug, cut the cable tie to remove the old battery, install the new battery and fix it with 2 new cable ties (be careful not to tie the battery cable). After the replacement is completed, the program must be tested in T1 mode and all four axes of A1-A4 must be re zeroed.

When changing the A1 axis oil, unscrew one M10x1 magnetic screw plug from the bottom frame and connect it to the oil discharge hose. Then slowly unscrew the two M18x1.5 magnetic screw plugs on the connecting rod arm to release pressure and oil; For the A2 axis, the top cover needs to be removed first, and the oil should be drained from the M10x1 screw plug of the connecting rod arm. Refueling uses a KUKA oil pump (0000-180-812) to inject oil in reverse from the bottom. Special reminder: The oil discharge amount is affected by the discharge time and oil temperature, and the oil replenishment amount should be based on the actual measured oil discharge amount; If the oil discharge amount is less than 70% of the specified amount, it must be flushed once with the measured oil amount before injection. If it is less than 50% (such as in inclined installation), it needs to be flushed twice. During the flushing period, the shaft should be run at a jog speed throughout the entire process. Before draining the oil, attention should also be paid to the possibility of pressure in the oil chamber. Release the pressure first before operation, and take precautions against high-temperature oil burns. The locking torque of M18x1.5 screw plug is 20 Nm, and the M10x1 screw plug is 7.5 Nm.

Zero point calibration

After replacing the motor, reducer, cable or battery, the zero point may drift and must be recalibrated. A1/A2 can use the calibration kit (0000-396-617) to align with the calibration slot, and then select Set Current to set the zero point on the KUKA. ControlStudio calibration page; A3/A4 use a dedicated calibration kit (0000-453-614) to seamlessly fit the L-shaped bracket notch with the calibration pin before setting. When there is no calibration tool, calibration can be done by visually aligning the engraved lines, but there may be human judgment errors. The alternative process for A3 zero point is: upper limit position → A4 returns to zero → A3 moves down 4 mm and then sets zero.