KUKA KR IONTEC HO Maintenance Troubleshooting Guide

Practical Maintenance and Troubleshooting of KUKA KR IONTEC HO

KUKA KR IONTEC HO is a series of six axis articulated arm robots designed for secondary area applications in food related environments. The models include KR 50 R2100 HO, KR 50 R2500 HO, and KR 70 R2100 HO. This series emphasizes hygienic lubrication and reliable operation, suitable for tasks such as handling, processing, and transferring parts or products. For engineers in the search solution stage, what is truly valuable is not just the parameter table, but a complete set of executable methods from installation, transportation, safety, maintenance to troubleshooting. This article focuses on this series of robots, and combines key data and engineering practice to compile a technical guide that is easy to use on site.

Product positioning and key parameters

The KR IONTEC HO series adopts a six axis series joint structure, mainly composed of a base, a rotating column, a connecting rod arm, an arm, an inline wrist, and electrical installation components. The differences between the three models are concentrated in load and arm span: KR 50 R2100 HO and KR 50 R2500 HO have a rated load of 50 kg and a maximum load of 61 kg; KR 70 R2100 HO has a rated load of 70 kg and a maximum load of 85 kg. In terms of arm span, the R2100 model can reach a maximum of 2101 mm, and the R2500 model can reach a maximum of 2501 mm. The repeatability accuracy is ± 0.05 mm, which is suitable for applications that require high trajectory consistency.

The overall protection level of the machine is IP65, and the arm and wrist can reach IP65/IP67. The noise level is below 69 dB (A). The installation method is flexible and can be installed on the floor, ceiling, wall, or at any angle. However, the tilt installation angle must be correctly written into the controller, otherwise it may cause accidental movement or overload. The operating environment temperature ranges from 0 ° C to 55 ° C, and the storage and transportation temperature ranges from -40 ° C to 60 ° C. Preheating may be required during low-temperature start-up. The controller is compatible with KR C4 and KR C5 M6/M7, with conversion names of KR50R2100, KR50R2500, KR70R2100, etc.

In terms of connecting cables, KR C4 uses X20-X30 motor cables and X21-X31 data cables; The KR C5 uses XD30, XD10 brake connectors, and XF31 data cables. The standard cable lengths are 7 m, 10 m, 15 m, 20 m, 25 m, 30 m, 35 m, and 50 m, with a maximum length of 50 m and a maximum of one expansion connection allowed. The cross-sectional area of the grounding conductor is 16 mm ², and M8 ring cable plugs are used at both ends. When wiring, the bending radius of the motor cable should not be less than 150 mm, and the bending radius of the data cable should not be less than 60 mm. They should be separately laid in metal pipes to avoid electromagnetic interference.

Key points for installation and transportation

Before installation, it is necessary to confirm that the foundation or machine frame can withstand the forces and moments generated during operation. There are two common installation methods: a mounting base with a centering device and a machine frame mounting component. The installation base kit R300x400 weighs approximately 26.7 kg and is suitable for concrete foundations. The concrete grade should reach C20/25. The foundation must be flat, without insulation or mortar layer, and the minimum thickness and edge distance should be determined based on whether there are edge steel bars. The machine frame installation component weighs approximately 2.3 kg and is suitable for steel structures and linear units. It is fixed with 8 M20x60-8.8 hexagonal bolts and tapered spring washers.

Before transportation, the robot must enter the transportation positions: A1 0 °, A2-125 °, A3 150 °, A4 0 °, A5-115 °, A6 0 °. During forklift transportation, the minimum load capacity of the forklift should reach 2.0 tons, and excessive internal and external movement should be avoided when entering the fork slot, which may cause overload of the fork slot. When using lifting equipment, certified lifting accessories must be used, and all lifting straps should be arranged according to the markings to prevent the robot from tilting or being damaged. Personnel are prohibited from staying under the robot during transportation to avoid vibration and impact. After transportation is completed, the fork groove and lifting accessories must be removed before entering the start-up process.

Before starting, check if the robot is properly secured; Is there any damage caused by external forces, such as dents or paint abrasion; Whether the motor and balance system are intact; Are all safety devices installed and effective; Whether the power supply parameters match; Is the grounding conductor and equipotential connection reliable; Is the connector securely locked. For robots that have been subjected to collisions or impacts, even if there is no obvious damage to the appearance, there may still be invisible damage. It is necessary to carefully inspect the motor and balance system, and replace the affected components if necessary.

Safe operation and mode management

In the safety logic of this series of robots, the A1 to A3 axes are equipped with mechanical end stops, but these end stops are mainly used to protect the machine rather than personnel. Personnel protection relies on the safety robot function of the controller or the optional A1 to A3 mechanical axis limiting device. The danger zone consists of a workspace and a stopping distance, and must be isolated by physical barriers, safety doors, etc. The safety door should be located outside the danger zone. If there is no physical protection, collaborative operation requirements must be met.

In terms of operation mode, T1 is a manual deceleration mode with a speed not exceeding 250 mm/s, suitable for teaching, programming, and program verification. T2 is a manual high-speed mode, only used for testing situations that require speeds higher than T1, and teaching and programming are not allowed. Automatic mode is only allowed to be used when all safety equipment and protective devices are complete and effective. If the robot stops inexplicably in automatic mode, it must not directly enter the danger zone and must first trigger an emergency stop.

When maintaining and repairing, five safety rules must be followed: power-off, prevent restart, confirm no power, ground and short circuit, cover or isolate adjacent live parts. The emergency stop device must remain available. If it is necessary to work while powered on, it can only be carried out in T1 mode and limited to the absolutely necessary range. Personnel with implants should maintain a minimum distance of 300 mm from the motor and brake. SmartPAD or KCP must be operated by authorized personnel and should be removed from the system immediately after disconnection to prevent misuse. The external keyboard and mouse can only be used during startup or maintenance, and the driver must be turned off and there must be no one in the danger zone.

Maintenance system and oil management

The maintenance cycle of KR IONTEC HO is closely related to load, environment, and operating mode. The routine maintenance nodes include: checking the tightening torque for the first 100 hours; 5000 hours of inspection to see if the hoses and cables are damaged; Lubricate cable group A1 for 20000 hours using Kl ü berfood NH1 34-401 grease, with a dosage of approximately 0.03 kg; replace A1 to A6 gear oil every 10000 hours or up to 5 years using Optileb GT 1800/460. The initial filling amounts are: A1 5.66 L, A2 2.49 L, A3 1.00 L, A4 0.33 L, A5 0.60 L, A6 0.24 L.

Before changing the oil, the robot should be at an operable temperature, but attention must be paid to the possibility of burns caused by high temperature oil and surfaces. The oil chamber may be under pressure, so ventilation should be done before opening the drain plug. When changing the oil in A1, move A1 to -90 °, remove the cover plate on the rotating column and base, and use M18x1.5 magnetic plug and oil drain pipe. When changing the oil in A2, place the robot in a position that is accessible to the refueling and draining holes. When changing the A3 oil, keep the arm and inline wrist level, and set the angle of A2+A3 to 0 ° for checking the oil level. When changing the A4 oil, the angle between A2 and A3 should be -68 °. When changing the oil in A5, A2+A3=0 °, A4=-77 °. When changing the oil in A6, A2+A3=0 °, A5=0 °, A4=53 °. The tightening torque for M18x1.5 plugs is usually 20 Nm, and for M10x1.0 plugs it is 7.5 Nm.

When lubricating cable group A1, it is necessary to remove the cover plates on the rotating column and base, check and apply lubricating grease, and then move A1 to evenly distribute the lubricating grease. Neutral, solvent-free, water-soluble, non flammable, and non corrosive cleaning agents should be used when cleaning robots. Do not use high-pressure cleaning machines, do not use compressed air to clean bearings and sealing points, and prevent cleaning agents from entering electrical or mechanical components. After cleaning, the cleaning agent should be completely removed, the corroded area should be inspected, and anti-corrosion measures should be taken again.

Practice of Motor Replacement and Maintenance

Motor replacement is a high-frequency task for on-site maintenance. When replacing the A1 motor, first disconnect the XM1 and XP1 connectors, remove the 4 M10x25-8.8-A2K hex screws, carefully remove the motor to avoid tilting. Clean the splines of the motor and gear input shaft before installation, apply Microlube GL 261 grease, check the O-ring, tighten the screws step by step in diagonal order, and finally insert the connector back and perform A1 mastering again. Before replacing the A2 motor, the connecting rod arm must be fixed with a sling to prevent the robot from moving on its own after disassembly. A2 uses 4 M10x25 screws. Before replacing the A3 motor, it is necessary to fix the inline wrist and robot arm with a sling, remove the 14 M6x16 screws on the A3 cover plate, and then remove the 4 M8x22 screws. After installation, it is also necessary to re master and test in T1 mode.

When replacing the motor, it is important to note that damaged gears or motor teeth can cause wear and early failure; Check if the teeth are damaged before installation; When inserting the connector, it must be aligned with the coding element to ensure anti twist locking; All high-strength screws, such as grade 10.9 and above, can only be tightened once to the rated torque and must be replaced after loosening. After the repair is completed, the corresponding axis should be moved to check for abnormalities, mastering should be performed, and then the program should be run in T1 mode. If the robot is equipped with a release device, it can move the A1 to A3 axes without driving energy after an accident or malfunction. After using the release device, all axles must be remastered and subjected to brake testing and T1 trial operation.

Common faults and troubleshooting ideas

The troubleshooting of KR IONTEC HO should revolve around "stopping distance, abnormal movement, oil leakage, cable wear, safety functions, and lost mastering". Firstly, stopping distance and stopping time are important parameters for safety assessment. The data of STOP 0 and STOP 1 will vary with load, speed, and extension distance. Taking STOP 0 as an example, the stopping distance of A1/A2/A3 for KR 50 R2100 HO is about 23.19 °/30.38 °/18.25 °, with a stopping time of about 0.29/0.36/0.20 s; KR 50 R2500 HO is about 29.60 °/22.57 °/19.59 °, with a time of about 0.37/0.37/0.22 s; KR 70 R2100 HO is about 37.62 °/21.05 °/21.66 °, with a time of about 0.38/0.30/0.27 s. Brake wear, load changes, and external forces can all affect the actual value, and it is recommended to check the stopping distance at least once a year.

If the robot experiences unexpected movement or sinks after power failure, it should be checked whether the brake is damaged, whether the load is too large, and whether the balance system is abnormal. If the collision end stops or the mechanical axis is restricted, the robot may no longer be able to operate safely and must be stopped and evaluated by professionals before resuming. If oil leakage is found, check the magnetic plug, sealing element, and oil chamber pressure, and ventilate before changing the oil. If the cable is worn, the bending radius, fixing method, and metal pipe isolation should be checked, and the motor cable and data cable should not be subjected to tension. If the safety function fails, it is strictly prohibited to operate the robot, and all safety circuits must be immediately repaired and verified.

The common troubleshooting steps can be summarized as follows: power off and lock; Check for external force damage; Check the motor and balance system; Check if the connector is securely locked; Check grounding and equipotential; Check the safety circuit and emergency stop; Low speed testing in T1 mode; If necessary, re master; If the problem involves gears, brakes, or structural components, original spare parts should be used and the fault should be recorded. After maintenance, functional testing must be conducted to ensure that all safety functions are effective.

Discontinuation, storage, and scrapping

When stopping the robot, first move it into the transport position, remove the tool and peripheral connections, disconnect the motor cable, data cable, and grounding conductor, loosen the 8 M20x60 bolts, and lift it vertically with a crane or forklift. The storage environment should be dry, dust-free, avoid temperature fluctuations, avoid direct sunlight and condensation. Robots should be cleaned, covered with plastic film, sealed for electrical and hose connections, and desiccants should be placed if necessary. When scrapped, they are classified by material: aluminum alloy components, copper cables, cast steel bases, steel gears and screws, electronic components, motors, plastic parts, as well as gear oil and lubricating grease, etc. Electronic components and motors are usually not disassembled and treated as electrical waste; Oil and grease should be disposed of in accordance with local regulations.

Overall, the reliable operation of KUKA KR IONTEC HO relies on standardized installation, strict transportation location management, proper use of safe modes, periodic oil and lubrication maintenance, as well as mastering and T1 testing after motor replacement. The most valuable approach for on-site engineers is to standardize the steps of stopping distance inspection, oil replacement, cable inspection, and motor replacement, and establish fault records. This can not only reduce unplanned downtime, but also quickly locate problems when searching for solutions, improving equipment availability and safety.