Industrial Robot Maintenance Tips: Your Comprehensive Guide

The adoption of industrial robots in the manufacturing sector has been on the rise, especially in environments that are harsh or demand high levels of work intensity and continuity.

Branded robots are more widely recognized due to their lower failure rate.

Despite the fact that industrial robots are well-designed, more integrated, and have a lower rate of failures, they still require regular routine inspections and preventative maintenance.

Some common types of robots include serial manipulators, Cartesian-coordinate robots, Delta parallel robots, scara robots, and automatic guided vehicles, among others.

This article will focus primarily on the maintenance of manipulators.

I. Main body maintenance of industrial robots

1. General maintenance

(1) Washing the Manipulator:

• Clean the base and arms of the robot on a regular basis.
• High-pressure cleaning equipment can be utilized, but direct spraying of the manipulator should be avoided.
• If the manipulator is coated with a grease film, remove it as necessary. (It is important to avoid using strong solvents such as acetone, and to avoid exposing the manipulator to plastic protection. To prevent static electricity buildup, non-conductive surfaces such as spray equipment and hoses should be wiped down with a damp cloth, rather than a dry cloth.)

(2) Cleaning and Maintenance of the Hollow Wrist:

• The hollow wrist should be cleaned frequently, as needed, to prevent the buildup of dust and particles.
• Clean using lint-free cloths.
• After cleaning the wrist, a small amount of vaseline or a similar substance can be applied to the surface of the wrist to make future cleaning easier.

(3) Periodic Inspection:

• Check for oil leaks.
• Verify that the gear clearance is not too large.
• Check for any damage to the cables connecting the control cabinet, purge unit, process cabinet, and manipulator.

(4) Checking the Fixed Bolts:

• The fastening bolts and clamps that secure the manipulator to its foundation must be kept clean and should not come into contact with corrosive liquids, such as water, acids, or alkalis.
• If the anti-corrosion protective layer, such as a galvanized layer or paint, is damaged, the affected parts should be cleaned and coated with anti-corrosion paint.

2. Shaft brake test

During operation, the brakes on each axis motor will naturally experience wear.

To ensure that the brakes are functioning properly, it is necessary to perform a test.

Testing Method:

1. Move the manipulator axis to its maximum weight position, where the total weight of the manipulator and all loads is at its highest (maximum static load).
2. Turn off the motor power.
3. Verify that all axes remain in their original positions.

If the manipulator does not shift when the motor power is turned off, this means that the braking torque is sufficient.

You can also manually move the manipulator to check if additional protective measures are required.

When the mobile robot stops suddenly, the brake will engage to help bring it to a halt, leading to wear.

Therefore, repeated tests must be conducted throughout the service life of the machine to confirm that it continues to maintain its original capacity.

3. System lubrication

(1) Lubrication of Gear Pairs and Gears:

• Ensure that the robot and related systems are closed and secured.
• Squeeze a small amount of grease (1 gram) into each choke and lubricate the gear pair grease nozzle and each gear grease nozzle individually. Avoid overfilling to prevent damage to the seals.

(2) Lubrication of the Hollow Wrist:

• For the 10 lubrication points in the hollow wrist, only a few drops of lubricant (1 gram) are needed for each grease nozzle.
• Do not add too much lubricant to avoid damaging the wrist seal and internal sleeve.

4. Check the oil level in the gearbox

Due to the varying positions of the lubrication openings, a specific inspection is necessary. Some of them may require rotating the device to a vertical position and opening the cover to perform the inspection.

5. Maintenance period

The frequency of maintenance can be adjusted as appropriate based on environmental conditions, the operating hours of the robot, and temperature.

• General maintenance: once per day.
• Axis brake test: once per day.
• Lubrication of 3-axis gear pairs and gears: once per 1000 hours of operation.
• Lubrication of the hollow wrist: once per 500 hours of operation.
• Lubricant in each gear box: change it in the first year, and then change it every 5 years thereafter.

II. The maintenance of the system control cabinet

1. Maintenance checklist

(1) Checking the Heat Dissipation of the Controller:

• It is prohibited to cover the controls with plastic or other materials.
• Leave enough space between the back and sides of the controller (>120mm).
• It is strictly forbidden to place the controller near a heat source.
• It is strictly forbidden to place debris on top of the controller.
• Avoid a dirty controller.
• Avoid one or more cooling fans not working.
• Avoid blockages at the fan inlet or outlet.
• Avoid a dirty air filter cloth.
• When the controller is not in use, keep its front door closed.

(2) Cleaning the Teaching Device:

• Clean the teaching device as needed.
• Although the panel paint film is resistant to most solvents, it should still be kept away from strong solvents like acetone.
• When not in use, remove the teaching device and store it in a clean place.

(3) Cleaning the Inside of the Controller:

• Clean the inside of the controller as needed, taking into account environmental conditions (e.g. once a year).
• Pay special attention to cleaning the cooling fan and air inlet/outlet.
• Use a dust-removing brush during cleaning and a vacuum cleaner to suck up dust. Do not use the vacuum cleaner to clean the components directly, as this may cause an electrostatic discharge and damage the components.
• Before cleaning the inside of the controller, be sure to turn it off.

(4) Cleaning or Replacing the Filter Cloth:

• To clean the filter cloth, wash it 3-4 times in 30-40℃ water with detergent.
• Do not wring out the filter cloth. Allow it to dry on a flat surface or blow it clean with clean compressed air.

(5) Replacing the Battery Regularly:

• The battery of the measurement system is a disposable (non-rechargeable) battery.
• When the battery needs to be replaced, a message will appear in the message log. After the message appears, the battery can maintain power for about 1800 hours (it is recommended to replace the battery when this message appears).
• The battery only works when the control cabinet is “powered off”.
• The battery life is about 7000 hours. If the control cabinet also controls the CBS unit or if it is an 8-axis robot, the battery life will be half of what is described above (using 2 SMU units).

(6) Checking the Cooler:

• The cooling circuit uses a maintenance-free closed system design, and each component of the external air circuit should be regularly inspected and cleaned as needed.
• When the environmental humidity is high, it is necessary to check that the drain outlet is regularly draining water.

2. Maintenance frequency

The frequency of maintenance can be adjusted as appropriate based on environmental conditions, the operating hours of the robot, and temperature.

• General maintenance: once per day.
• Cleaning/replacing the filter cloth: once per 500 hours of operation.
• Battery replacement for the measurement system: twice per 7000 hours of operation.
• Replacement of the computer fan unit and servo fan unit: once per 50,000 hours of operation.
• Checking the cooler: once per month.