Mastering IRB 6700 Maintenance
A Visual Guide to Checking Gearbox Oil Levels (Axes 1-6)
Ensure peak performance, precision, and longevity of your ABB IRB 6700 industrial robot with this comprehensive maintenance guide.
Why This Maintenance is Critical
The ABB IRB 6700 is a powerhouse industrial robot, built for demanding applications and long service life. Like any high-performance machine, regular maintenance is key to ensuring its reliability, precision, and longevity. One of the most fundamental, yet critical, routine checks is verifying the oil levels in its six axis gearboxes.
Proper lubrication is the lifeblood of your robot's gear systems. Incorrect oil levels – whether too low or too high – can lead to premature wear, overheating, seal damage, and ultimately, costly downtime and repairs.
Target Audience
Maintenance Technicians, Robot Service Engineers, and anyone responsible for the upkeep of ABB IRB 6700 robots.
Proper Lubrication
Prevents metal-on-metal contact between gear teeth, reducing friction and wear while ensuring smooth operation.
Heat Dissipation
Oil helps carry away heat generated during operation, preventing overheating and extending component life.
Protection
Inhibits corrosion and helps keep contaminants out, protecting vital mechanical components from damage.
Performance
Ensures smooth, precise movement and optimal power transmission, maintaining your robot's accuracy and efficiency.
Risks of Low Oil
- Insufficient lubrication leads to increased friction
- Rapid wear of gear teeth and bearings
- Overheating due to increased friction
- Potential catastrophic gear failure
- Expensive repairs and production downtime
Risks of High Oil
- Excessive oil churning and foaming
- Overheating from increased resistance
- Increased pressure on seals
- Potential oil leaks and environmental issues
- Reduced efficiency and energy waste
Safety First: Critical Precautions
Before starting any maintenance task, safety is paramount. Always adhere to your facility's Lockout/Tagout (LOTO) procedures.
DANGER: Power Off Completely
Turn off ALL power sources to the robot and controller before entering the robot's working area:
- Main electrical power
- Hydraulic pressure supply
- Air pressure supply
Ensure the system cannot be accidentally re-energized. Refer to your manual for switching off main power (Page 46).
Illustration of main power switch concept
WARNING: Oil Handling Safety
Gearbox oil can be hot after operation and may pose chemical hazards.
- Always consult the oil manufacturer's safety data sheet (MSDS)
- Wear appropriate Personal Protective Equipment (PPE), including safety glasses and chemical-resistant gloves
- Open oil plugs slowly to release any built-up pressure safely
- Clean up spills immediately
- Dispose of used oil according to local environmental regulations
Illustration of general lubricant warnings
CAUTION: High Temperatures
Motors and gearboxes can be extremely hot after operation.
- Allow sufficient cooling time before touching components
- Use temperature-resistant gloves when necessary
- Be aware that internal components may remain hot even when external surfaces have cooled
- Use caution when draining hot oil
Illustration of high-temperature warning
Essential Tools & Preparation
Standard Toolkit
Allen keys or sockets appropriate for the oil plugs (refer to your standard toolkit list, Page 559).
Correct Lubricating Oil
Crucially, identify the specific type of oil required for your IRB 6700 model and application. This information is found in the Technical Reference Manual.
Using the wrong oil type can severely damage the gearbox. Have a supply ready in case topping up is needed.
Torque Wrench
Calibrated to apply the correct tightening torque (24 Nm for these plugs). Proper torque prevents leaks while avoiding damage to threads.
Measuring Tool
A clean dipstick, ruler, or measuring tape marked appropriately for checking levels relative to the sealing surface (Optional but Recommended for Axis 1 & 6).
Positioning the Robot
For most axes, the robot needs to be moved to its calibration position (all axes at 0°) for an accurate oil level check. Axis 6 has an alternative check position.
Why? The orientation of the gearbox affects where the oil settles, ensuring the level plug corresponds correctly to the required fill level.
Oil Type Verification
Double-check the oil type specified in the Technical Reference Manual - Lubrication in Gearboxes against the oil you have on hand.
Mixing incompatible oils can cause foaming, reduced lubrication properties, and damage. If you inherit maintenance duties for a robot, try to verify the oil currently in use if possible, or consider a full oil change if unsure and the maintenance history is unclear.
Step-by-Step Oil Level Checks (Axes 1-6)
Follow these steps for each axis, referring to the specific diagrams in your product manual (pages 104-117) for exact plug locations.
1 Axis 1 Gearbox (Manual Pages 104-106)
Position
Calibration Position (ensure Axis 1 is at 0°).
Locate Plug
Identify the oil plug on the Axis 1 gearbox (refer to manual diagram, pg 104).
Procedure
- Clean the area around the oil plug.
- Slowly remove the oil plug, releasing any potential pressure.
- Check Level: The correct oil level is 58 mm ± 5 mm below the sealing surface of the oil plug hole. Use a clean measuring tool (dipstick/ruler) to verify.
- Adjust Level (If Needed): Carefully add the correct type of oil if low, or drain some if high.
- Clean the oil plug and threads.
- Refit the oil plug.
- Tighten the plug to 24 Nm using a torque wrench.
- Proceed to check subsequent axes.
Refer to manual page 104 for exact diagram
Tip
Mark your measuring tool at 58mm for quick reference during future checks.
2-5 Axes 2-5 Gearboxes (Manual Pages 107-114)
The procedure for Axes 2, 3, 4, and 5 follows a similar pattern, with the main difference being the location of the level plug. Refer to your manual for the exact location diagrams for each axis.
Position
Calibration Position (all axes at 0°).
Locate Plug
Identify the level plug on the specific axis gearbox.
- Axis 2: refer to manual diagram, pg 107
- Axis 3: refer to manual diagram, pg 109
- Axis 4: refer to manual diagram, pg 111
- Axis 5: refer to manual diagram, pg 113
Procedure (All Axes 2-5)
- Clean the area around the level plug.
- Slowly remove the level plug.
- Check Level: The oil level should be between 0 mm and 10 mm below the bottom edge of the plug hole. The oil should be visible at or just below the opening.
- Adjust Level (If Needed): Add correct oil if low, or drain if high.
- Clean the plug and threads.
- Refit the level plug.
- Tighten the plug to 24 Nm.
- Proceed to the next axis check.
Visual Check Reference
The oil level should be visible at the bottom of the plug hole
Consistency Check
The procedure for Axes 2-5 is identical except for plug location. Maintaining a consistent workflow reduces errors.
6 Axis 6 Gearbox (Manual Pages 115-117)
For Axis 6, there are two different methods available. Choose the one that works best for your situation.
Method 1 (Calibration Position)
Position
Calibration Position.
Locate Plug
Identify the oil level plug (refer to manual diagram, pg 115).
Procedure
- Clean area around the level plug.
- Remove level plug slowly.
- Check Level: The correct oil level is 50 mm ± 5 mm below the sealing surface of the plug hole. Use a clean measuring tool.
- Adjust level if needed.
- Clean plug/threads.
- Refit plug.
- Tighten to 24 Nm.
Method 2 (Specific Angle)
Position
Jog Axis 5 to +77°. Keep other axes at calibration position.
Locate Plug
Identify the oil fill plug (refer to manual diagram, pg 115).
Procedure
- Clean area around the fill plug.
- Remove fill plug slowly.
- Check Level: In this specific orientation, the oil level should be between 0 mm and 10 mm below the bottom edge of the fill plug hole.
- Adjust level if needed.
- Clean plug/threads.
- Refit plug.
- Tighten to 24 Nm.
Why Two Methods?
The design of the Axis 6 wrist assembly means the orientation significantly impacts the oil level relative to a single plug. Method 1 uses a dedicated level plug and requires measurement. Method 2 cleverly uses the fill plug as a level indicator when Axis 5 is tilted to exactly +77°, avoiding the need for a separate measuring tool.
Interpreting the Results & Next Steps
Consistently Low Levels
If you frequently find oil levels low on a particular axis, investigate for leaks around seals or gaskets. A significant drop in oil level since the last check warrants immediate investigation for a more substantial leak.
High Levels
If an axis is overfilled, drain the excess to the correct level to prevent overheating and seal damage. Determine if it was previously overfilled during maintenance.
Contaminated Oil
If the oil appears milky (water contamination), dark and sludgy, or contains metal particles, it indicates a more serious issue. The oil should be changed, and the cause investigated (e.g., seal failure, excessive wear).
First Test Run
After completing checks or adjustments, always follow the safety procedures for a first test run (Page 44) to ensure everything operates correctly.
Documentation
Always log your maintenance activities. Record the date, the robot serial number, the axis checked, the oil level observed (e.g., "OK", "Low - added 50ml", "High - drained approx. 100ml"), and your initials.
This history is invaluable for tracking potential issues and planning future maintenance.
Best Practices for Topping Up Oil
- Use the CORRECT Oil: This cannot be stressed enough. Verify the oil type against the Technical Reference Manual.
- Clean Funnel/Transfer Device: Use a spotlessly clean funnel or oil transfer pump designated only for the correct type of gearbox oil.
- Add Oil Slowly: Add small increments of oil, allowing time for it to settle before re-checking the level.
- Don't Overfill: Carefully monitor the level using the specified method. Overfilling can be just as detrimental as underfilling.
- Clean Up Thoroughly: Wipe away any spilled oil from the gearbox exterior and surrounding area.
Environmental Factors & Check Timing
Temperature Matters
Oil volume expands slightly when hot and contracts when cold. Ideally, perform oil level checks when the robot is at a relatively consistent temperature.
Checking immediately after heavy operation (when the oil is hot) might show a slightly higher level than when cold. Checking in extreme cold might show a slightly lower level.
Best Time for Checks
While the manual doesn't specify, incorporating these checks before starting a production shift (when the robot is likely cool and has been static) is often a practical approach.
This allows time for any necessary top-ups or minor leak investigations before production begins.
Focus on Trends
While minor fluctuations due to temperature are normal, significant drops between checks (performed under similar temperature conditions) are cause for investigation. Think of oil level checks as a quick health screening for your gearboxes.
Troubleshooting Common Issues
Stuck Oil Plug
- Ensure you are using the correct size and type of tool (Allen key/socket) and that it's fully seated to avoid stripping the head.
- Apply steady, firm force. Avoid jerky movements.
- If extremely tight, a penetrating oil might be used sparingly around the plug threads (allow time to soak), but be extremely careful not to contaminate the gearbox interior.
- In severe cases, applying localized heat cautiously to the gearbox housing around the plug might help expand the metal slightly.
- Consult senior technicians or ABB support if unsure.
Damaged Plug Head (Stripped)
- Stop attempting removal with the standard tool.
- Specialized stripped-screw/bolt extractors may be required.
- This often necessitates more advanced maintenance intervention.
Minor Seepage Around Plug
After correctly tightening the plug to 24 Nm, if there's still minor oil seepage, the plug's sealing surface or the gearbox threads might be slightly damaged, or the sealing washer (if present) could be compromised.
Clean the area thoroughly and monitor closely. If seepage persists, schedule a replacement of the plug and potentially re-evaluate the thread condition.
Difficulty Reading Level (Axis 1 & 6 Method 1)
- Ensure your measuring tool is inserted straight down.
- Use a flashlight to improve visibility inside the plug hole.
- Wipe the tool clean and take multiple readings if unsure. The oil level should be consistent.
Conclusion
Regularly checking the gearbox oil levels on your ABB IRB 6700 is a fundamental maintenance task that directly impacts its health and performance.
Regular Maintenance
Integrate these checks into your preventative maintenance schedule.
Follow Manuals
Always refer to your specific ABB manuals for definitive procedures.
Safety First
Never compromise on safety protocols during maintenance.
By following these steps, adhering strictly to safety protocols, using the correct type of oil, and applying the specified torque, you can help ensure your robot operates reliably for years to come. Remember, consistent, careful maintenance is the cornerstone of efficient robotic automation.