Tips For Extending The Life Of A Ball Screw And Ball Nut
Ball screw and nut combinations are used in a wide variety of applications. They are primarily designed to allow the rotational motion to a linear movement with limited impediment from friction.
The threading on the ball screw acts as a groove for the balls that hold the ball nut up and off the screw. In this way, the nut is not actually in contact with the screw; rather it rides on the ball bearings that are circulated through the ball return system which can be designed in different ways.
Even though the ball screw and nut assembly is durable, it is also designed for extreme precision of movement. Storing and maintaining the ball screw assembly will be essential to extend the life of the company and avoid the need for repairs or placement of the ball nut or screw.
As these parts are often custom made for a particular piece of equipment, it isn’t unusual for a business to have a spare part in inventory to prevent lengthy downtime if there is a failure of the current part. When storing a ball screw and nut assembly, be sure to keep the entire length of the screw supported when in the vertical position or fully horizontal. Simply supporting the two ends, particular on long screws, can result in swaying or bending of the screw.
Long storage times can result in the actual ball bearings having slightly flattened sides. To avoid this, move the ball nut up or down the screw on a regular basis. This will not be an issue unless the storage period is extended.
Talk to the manufacture of the ball screw and nut assembly before using any type of lubrication. In general, spray on lubricants or those that contain paraffin are not recommended as they can cause a sticky surface on the interior of the ball nut, resulting in poor performance and increased friction.