The importance of changing and maintaining the grease in your robot is similar to importance of changing the oil in your vehicle. Over time, oil and grease both break down, losing their viscosity and effectiveness in your robot/vehicle. You wouldn’t let your car run for a year or two on the same oil, just like you shouldn’t allow your robot to run two years with the same grease…unless you plan to buy a new robot every two years.
After 500-700 hours, the grease in your robot will begin to break down, which can be rough on the joints and impact the robot’s performance. If the robot is used daily, the color of the grease should be inspected once a month, to check the color and consistency.
Before starting to grease your robot – read your specific robot manual for information on your robot model. The manual will give you information on different types of grease, which is important, because not all of your joints will run on the same type of grease. If you do not read the service manual and fail to grease your robot properly, it could void the robot’s warranty, as well as causing slowdowns in your production due to broken seals or malfunctioning parts.
While every robot joint needs to be greased, the second and third joints on your robot may be the dirtiest because they move the most. While all robot joints have an in plug, only those with gears will also have an out plug – like the second and third joints on most robots. What kind of grease should you use to grease joints? Check your robot manual, as mentioned above, but many robots use VIGO grease, a synthetic grease that does not break down as easily as other types of grease on the market.
So, now that you’ve read your manual and purchased your grease, what do you do? First, you make your robot “dance” – you turn it on and allow it to move in all directions, with all axes moving. This will soften the existing grease, and make expulsion easier. Remove the in and out plugs for your axes and allow the robot to continue to move. If you do not keep the robot moving, the old, dirty grease will settle into the bottom, and the new grease will glide over it, making it appears as if the process is complete. Then, when you run the robot, and check the grease a month later, it may be black again. Once you have expelled all of the old grease, place a spot of grease over the out plug of the joint. If you are putting in new grease in the right area, a bubble should form over the out plug as air is pushed out of the joint. Once all of the new grease is added, you are ready to roll. Replace all of the plugs, and you’re set for the next 500-700 hours.
Are you interested in learning more about greasing your robot, or which robot grease is right for your robot? Then you should contact RobotWorx, a certified integrator for several different robotics companies. We carry grease for ABB, FANUC, Motoman, Universal Robots, and KUKA robots, including VIGO grease.