A question that often comes up for miniature ball screws – how do I lubricate it if there is no port on the ball nut? Good question! If you check our web site there is quite a lot of detailed information on lubricant types and wiper types, including precise amounts to use when re-lubricating:
But this all presumes there is a lubrication port located somewhere on the ball nut. What if there isn’t? Well, the short answer is: apply the lubricant directly to the shaft! And just as for the ball nut, use only a small amount and ensure it is evenly distributed, as much as possible, along the shaft. It would be a good idea to remove any dirty or discolored grease that is still on the screw before applying new grease. You may use a lint-free cloth for that, but do not use any detergents. And never use aggressive solvents such as acetone! Fresh grease is best applied with a small paintbrush. Once the shaft has been lubricated, run the nut back and forth several times to distribute the lubricant. Overlubricating is as bad as, and sometimes even worse than, under-lubricating. And if you inspect the miniature ball screw and you see a lubricant film on the shaft, leave it alone until a subsequent inspection. If the nut is fitted with white or blue plastic wipers, do not remove them! These wipers will still let enough grease pass.
Aerospace ball screws have different lubrication procedures. Check the maintenence instructions for the actuator for proper grease type and how to re-fill the nut.