Troubleshooting KUKA KR 1000 Titan

KUKA KR 1000 titan and KR 1000 L750 titan maintenance and troubleshooting

KUKA KR 1000 titan and KR 1000 L750 titan are six axis articulated robots designed for ultra heavy load scenarios, covering models such as KR 1000 titan, KR 1000 titan F, KR 1000 L750 titan, KR 1000 L750 titan F. They are commonly used for handling large workpieces, loading and unloading heavy-duty machine tools, casting, heavy-duty assembly, and special processes. For on-site engineers, the real tricky problem is not "how to program", but how to quickly judge and restore the operation of the robot in a hierarchical manner without compromising safety integrity when there is abnormal pressure in the balance system, abnormal noise in the wrist, gear oil leakage, wear on the straight wrist teeth, motor overheating, or safety circuit shutdown.

Product positioning and core structure

The KR 1000 titan adopts a six axis articulated arm structure, with main components including a linear wrist, arm, connecting rod, rotating column, base, balance system, electrical installation, and connecting cables. The linear wrist consists of three axes A4, A5, and A6, which are driven by a motor installed at the rear end of the arm through a transmission shaft. The wrist gearbox is supplied with oil from three independent oil chambers. The rotation range of A5 is limited by the mechanical end stop. The F variant is designed for harsh environments such as casting, with pressure applied inside the arm to prevent moisture and dust from entering. The wrist is coated with heat-resistant reflective silver paint, and the entire machine has a special paint surface and transparent protective coating.

The arm is connected to a straight wrist and a connecting rod, and A3 to A6 motors and transmission shafts are installed internally. The connecting rod is located between the arm and the rotating column, with a gearbox on each side, driven by two motors through the input stage. Install A1 and A2 motors inside the rotating column. The base is connected to the installation base, and the internal layout includes electrical installation and energy supply interfaces. Forklift slots are also provided on the base for easy transportation. The balancing system is installed between the rotating column and the connecting rod, using a closed hydraulic pneumatic system consisting of two diaphragm accumulators, hydraulic cylinders, hoses, pressure gauges, and safety valves, used to balance the A2 axis load torque. The accumulator is filled with nitrogen gas, and when the connecting rod is vertical, the balance system has the smallest effect. The greater the deflection, the hydraulic oil is pressed into the accumulator, generating reactive force compensation.

The electrical installation includes motor cables and control cables from A1 to A6, all of which are plug-in connections. The RDC box, multifunctional housing, and connector are installed on the push in module of the base. Connect the cable from the controller to the robot, with a grounding conductor cross-sectional area of 16 mm ² and M8 ring terminals at both ends. The F variant also needs to be connected to compressed air, with an initial pressure regulator set at 0.01 MPa. The compressed air should be oil-free and water free, in compliance with ISO 8573-1:2010 7:4:4, and consume approximately 0.1 m ³/h.

Technical data and load foundation

KR 1000 Titan has a rated load of 1000 kg, a maximum load of 1000 kg, a maximum arm span of 3202 mm, a body weight of approximately 4690 kg, a workspace of approximately 79.8 m ³, a repeatability accuracy of ± 0.1 mm, a protection level of IP65, an F-variant wrist IP67, and a noise level of less than 75 dB (A). KR 1000 L750 Titan has a rated load of 750 kg, a maximum load of 750 kg, a maximum arm span of 3601 mm, a body weight of approximately 4740 kg, and a workspace of approximately 122.6 m ³. The weight of the F variant is approximately 4750 kg. The controller can be equipped with KR C5 L6/L7, KR C4, or KR C2 edition2005.

Axis motion range: A1 ± 150 °, A2-130 °/17.5 °, A3-110 °/145 °, A4 ± 350 °, A5 ± 118 °, A6 ± 350 °. Speed under rated load: A1 58 °/s, A2 50 °/s, A3 50 °/s, A4 60 °/s, A5 60 °/s, A6 72 °/s. In terms of flange load, during normal operation, the axial force F (a) is about 11200 N, the radial force F (r) is about 15000 N, the tilting moment M (k) is about 3300 Nm, and the flange moment M (g) is about 5400 Nm. Under emergency stop conditions, F (a) is about 12650 N, F (r) is about 24750 N, M (k) is about 9350 Nm, and M (g) is about 8050 Nm. Tools and loads must be able to withstand these forces and moments for a long time. The load data must be input into the robot controller, and path planning will consider the load. The mass inertia must be verified by KUKA Load.

Install flange with a diameter of 200 mm, thread M16, quantity 16, minimum screw depth of 24 mm, maximum screw depth of 25 mm, screw grade 10.9, positioning element 12 H7. In terms of foundation load, the normal vertical force F (v) is about 61500 N, maximum 70000 N; the horizontal force F (h) is normal 21400 N, maximum 35500 N; the tilting torque M (k) is normal 102200 Nm, maximum 133700 Nm; the torque M (r) around A1 is normal 36600 Nm, maximum 99700 Nm. The foundation must withstand these loads for a long time. The supplementary loads on A1 and A2 are not included in the calculation of foundation loads and must be taken into account as vertical forces.

Installation foundation and transportation

The installation methods mainly include installing the base with centering C1300 and installing the machine frame. Install the base weighing approximately 1165 kg, using chemical anchor bolts and 12 M30x90-8.8-A2K hex bolts, with concrete strength of at least C20/25. There shall be no insulation layer or mortar layer between the base and the concrete. When using chemical anchor bolts, the drilling diameter should be 18 mm. Diamond tools or coring drills must not be used, and setting tools approved by the anchor bolt manufacturer must be used. The installation surface must be flat and filled with leveling material if necessary, but the area where the robot tightens the bolts must not be covered by leveling material. When installing the robot, gradually tighten the 12 M30 bolts in diagonal order to 1330 Nm. After running for 100 hours, they must be tightened again.

The machine frame is installed for steel structures and linear units, weighing approximately 3.52 kg, using 12 M30x90-8.8-A2K hex bolts, sword pins, and centering pins. The installation surface needs to be processed, with high flatness requirements. After installation, tighten to 1330 Nm and re tighten after 100 hours.

The robot must be moved to the transport position before transportation. The standard transportation positions are A1 0 °, A2-130 °, A3 130 °, A4 0 °, A5 90 °, A6 0 °. During forklift transportation, there are fork slots on the base, and the minimum load capacity of the forklift is 6 tons. If a transport frame is used, the minimum load capacity of the forklift or crane is 8000 kg, and the total weight of the robot and transport frame is about 5600 kg. Three lifting rings and three legged lifting devices are used during lifting, with leg markings G1 to G3. Vibration and impact should be avoided during transportation, and tools and additional equipment should be removed to prevent center of gravity deviation. The standard lengths of connecting cables are 7 m, 10 m, 15 m, 20 m, 25 m, 30 m, 35 m, and 50 m, with a maximum of 50 m and a maximum of one expansion allowed. The bending radius for the fixed laying of motor cables shall not be less than 150 mm, and for data cables shall not be less than 60 mm. Motor cables and data cables shall be laid separately, and EMC measures shall be taken if necessary.

Safety and Debugging Inspection

The danger zone consists of a workspace and a stopping distance. Mechanical end stop and optional mechanical axis limit are used to restrict the working range of A1 to A3. Before debugging, all safety functions must be checked, including emergency stop, enable switch, mode selection, safety door, external safety stop, and safety output. T1 is in manual deceleration mode, with a speed not exceeding 250 mm/s; T2 is manual high-speed mode; AUT is in automatic mode. New or modified programs must be tested under T1 first.

Five safety rules must be followed during maintenance and repair: power off, prevent accidental restart, confirm that the system is out of power, ground and short-circuit, cover or isolate adjacent live parts. Even if the controller is turned off, some components may still have a voltage of 50 V to 780 V for several minutes. The robot system must be disconnected from the main power supply and cannot rely solely on emergency stop or safe stop. Hot surfaces, oil pressure, nitrogen pressure, and extrusion risks should all be prevented. The motor and brake will generate electromagnetic fields, and personnel wearing implants should maintain a distance of 300 mm from the motor and brake. Unauthorized modifications may render warranty and liability invalid.

Before starting, the default password must be changed, and the robot installation, fastening, cable connection, grounding conductor, and equipotential connection must be checked. If there is a significant difference between the internal temperature of the controller and the ambient temperature, it is necessary to wait for temperature equilibrium to prevent condensation. If the robot is subjected to external forces such as collisions or impacts, it may cause invisible damage and the motor and balance system must be checked. Security features must be tested. The brake test must be performed regularly and the system will force it to be carried out, and it cannot be turned off. The balancing system belongs to pressure equipment and must be operated by qualified personnel. Before maintenance, the supported components must be fixed and depressurized.

Maintenance cycle and oil management

The maintenance cycle is based on technical data and operating conditions. Check the torque of the fastening bolts and nuts 100 hours after startup. Every 2000 hours or up to 6 months, lubricate the main bearings with 4 lubrication nozzles, A1 at 0 °,+30 °, and+60 ° positions, using LGEP 2, with a total usage of approximately 12 × 8 cm ³=96 cm ³. Check the balance system pressure every 6 months. If the oil pressure is lower than the set value of 5 bar, adjust or supplement Hyspin ZZ 46 hydraulic oil, and check the lead seal of the accumulator safety valve. Lubricate the rotating column and connecting rod bearings every 5000 hours or up to 1 year, using LGEV 2, with approximately 50 g per lubrication point.

Replace gear oil every 20000 hours or 5 years. A1 uses Optigear ALR 320 with an initial volume of 25.0 L; A2 uses Optigear Synt. ALR 150 with an initial volume of 24.0 L; A3 is 12.0 L; A4 is 10.0 L; A5 is 3.0 L; A6 is 10.0 L. The oil change interval for the F variant is shortened to 10000 hours. Lubricate the A1 cable assembly every 20000 hours or 5 years using Optitemp RB2, approximately 100 g. If the oil temperature exceeds 60 ° C, the maintenance interval must be shortened and KUKA Service consulted.

Gear oil drainage must be carried out at operating temperature, first release pressure. A1 oil discharge requires moving A1 to -90 °, releasing the M22x1.5 magnetic plugs of the two motor towers for exhaust, and connecting the oil pipe to the service valve for oil discharge. Fill from below, the oil level should be between the two marks on the oil level indicator, recheck after 5 minutes, and the torque of the ventilation plug should be 12.5 Nm. For A2 oil discharge, loosen the two oil pipe joints and fill from below until the oil is discharged from both sides of the joints. A3 uses two service valves for oil discharge and filling. A4/A5/A6 are three independent oil chambers, using M27x2 magnetic plugs, with a torque of 30 Nm after filling. If the amount of discharged oil is less than 70% of the specified amount, it needs to be flushed once with discharged oil; Less than 50%, rinse twice and move the entire axis range at a jog speed during the rinsing process.

Balance system inspection and replacement

When checking the balance system, manually move A2 to -90 ° and wait for 1 minute. The ground robot pressure for KR 1000 titan and KR 1000 titan F should be 130 bar ± 15 bar (20 ° C). The ground robot pressure for KR 1000 L750 titan and KR 1000 L750 titan F should be 120 bar ± 15 bar (20 ° C). If there is abnormal pressure or deviation in application, a dedicated pressure gauge should be used for measurement and KUKA Service should be consulted. Check the hydraulic system, fittings, hoses, accumulator, and safety valve to confirm that there are no leaks, damage, or dirt.

When replacing the balance system, the robot should be in mechanical zero position, A2 should be movable, and firmly fixed on the ground. The weight of the balancing system is approximately 150 kg, and approved lifting devices must be used to prevent falls and uncontrolled movements. First, loosen the bellows clamp, move the connecting rod so that the clamping sleeve can be inserted between the hydraulic cylinder and the hinge joint, and clamp the piston rod. Lift the balance system with a crane, release pressure, pull out the pin, and remove the balance system. Before installing the new balance system, remove the anti-corrosion and move the connecting rod to about -85 ° or a suitable position. Insert the hinge joint, spacer ring, and pin, paying attention to the positioning pin on the pin entering the groove. The torque of the M16x230-8.8 screw is 195 Nm. After installation, 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.

Motor and linear wrist replacement

When replacing the A4/A5/A6 motor, power off and lock it first, remove the XM/XP connector, fix the motor with a sling, remove the 4 M12x30-8.8 Allen screws, and take out the motor. The F variant requires replacement of the seal between the motor and arm. Clean the motor teeth and drive shaft, apply Microlube GL 261, check the O-ring, tighten 4 Allen screws in diagonal order to 78 Nm, reconnect the plug, and perform mastering. A1 motor weighs about 32 kg, A2 motor weighs about 44 kg. When replacing, attention should be paid to lifting and hot surfaces.

The replacement of the straight wrist belongs to the major repair level. The weight of the straight arm is about 570 kg, and a crane or lifting device with sufficient load-bearing capacity must be used. Remove 22 M16x180-10.9 black Allen screws, note that there are still two pan head screws on the same hole circle that cannot be loosened. When pulling out the straight wrist, do not tilt it, and the gap between the arm and the straight wrist should be even. Clean all teeth and apply Microlube GL 261 before installation, ensuring that A4 and A6 are in the zero position. After inserting the straight wrist, gradually tighten the 22 M16x180-10.9 screws in diagonal order to 250 Nm. After installation, perform A4, A5, A6 mastering, T1 trial run to check for abnormal noise and leakage.

The release device is used to move A1 and A2 without driving energy in emergency situations. Before use, turn off the controller and lock it, remove the corresponding motor, install a ratchet, hexagonal socket or drive shaft, and manually move the shaft. After moving, all axes must be re masterned, brake tested, and tested under T1.

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. KR 1000 titan should be 130 bar, L750 should be 120 bar. If 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.

Wrist abnormal noise or positioning drift: Check the transmission shaft teeth, straight wrist teeth, bearings, and lubrication status; If worn or discolored, replace the drive shaft or straight arm.

Gear oil leakage: Check the magnetic plug, oil pipe, service valve, O-ring, and gearbox seal, and tighten according to torque.

Motor overheating: Check the load, duty cycle, ambient temperature, cooling, brake holding, and motor current to confirm that the load data has been input into the controller.

Cable wear or interference: Check the cable group, bending radius, shielding, separate laying, and A1 cable group lubrication.

Zero point loss: Mastering A1 to A6 again.

Abnormal braking: Conduct a braking test to check the parameters of the brake, motor, and controller.

Automatic mode cannot start: check safety door, operate safety signal, external emergency stop, confirm button, and mode selection.

Abnormal noise after replacing the straight wrist: Check if the teeth are damaged, if the screw torque reaches 250 Nm, if A4/A6 is in the zero position, and if the mastering is correct.

After replacing the balance system, the pressure is unstable: check the hydraulic oil filling amount, accumulator pre charge pressure, exhaust and leakage.

Insufficient lubrication of the main bearing: Add LGEP 2 through 4 lubrication nozzles at positions 0 °,+30 °, and+60 ° in A1 every 2000 hours or 6 months.

Oil contamination or insufficient oil level: Check the discharged oil level. If it is below 70% or 50%, perform flushing and use the specified oil.

After maintenance, functional testing must be conducted to ensure that all safety functions are effective. The replaced components must use original parts or equivalent approved parts. Screws with a rating of 10.9 or above or certified by testing can only be tightened once to the rated torque, and must be replaced after loosening. Common auxiliary materials include Drei Bond 1305、Drei Bond 1342、Drei Bond 5204HV、Loctite 510、Hyspin ZZ 46、LGEP 2、LGEV 2、Microlube GL 261、Optitemp RB2、Optigear ALR 320  And Optigear Synt. ALR 150.

Key points of standards and compliance

KR 1000 titanium involves the Machinery Directive 2006/42/EC, EMC Directive 2014/30/EU, Pressure Equipment Directive 2014/68/EU, as well as standards such as EN ISO 10218-1, EN ISO 12100, EN ISO 13849-1/-2, and EN ISO 13850. The F variant has higher dust, lubricant, coolant, and water vapor resistance, and adopts a special paint surface and transparent protective coating. If used for other environmental conditions, KUKA Deutschland GmbH must be consulted. The balance system contains nitrogen and hydraulic oil, which may involve UN 3164 during transportation, and must be depressurized before disposal. Industrial robots must be integrated into a complete system and undergo compliance assessment before they can operate.

Overall, the reliability of KUKA KR 1000 titan and KR 1000 L750 titan depends on the installation foundation, balance system, gear oil, linear arm, motor, and safety circuit. Regularly checking pressure, oil level, teeth, clearance, and torque can detect abnormalities in the early stages of faults. When encountering abnormal pressure, abnormal noise, leakage or shutdown, first lock it safely, and then investigate according to the levels of power supply, safety circuit, balance system, linear arm, gear oil and motor. This can reduce unplanned downtime and maintain stable operation of overloaded robots under harsh working conditions.