There are various factors to a ball screw and choosing the right one, including accuracy, speed, operating load, and environment. But the functionality of a ball screw doesn’t stop there. Without a lubricant, the screw can experience wear and tear and impact the machine’s usability. Before you apply just any lubricant, understanding the different options available and which works best is critical.
Here is a brief look at the different lubricants used for ball screws!
There are many oils on the market, and it might feel right to grab the first thing you find. But choosing the right lubricant is incredibly important for your machine’s ball screw. If an oil is too viscous or has a heavy application, this allows heat buildup in the ball screw assembly. On the other hand, if the application is too low or with low viscosity, you expose the assembly to significant wear.
The suggested flow rate specifications for optimal oil functions include:
- Amount of ball circuits
- Ball screw’s orientation
- Operational environment
It’s best to use wipers when applying a grease lubricant and place it near the root end of the ball track. Speed is not a critical criterion for grease because grease is the most accepted lubricant for a machine’s spindles.
Typically, a synthetic grease is better than a mineral-based option because synthetic can function over various temperature ranges. Synthetics also offer more durability because of the viscosity required for optimal film depth.
An example of optimal consistency follows a formula of cm^3 per ball circuit. If a 25 mm diameter ball screw has six circuits, it will require .4cm^3 per circuit or 2.4cm^3 of total grease.
Lower numbers are associated with better flow, while a firmer consistency correlates with higher numbers. When leaking becomes a concern, referring to these balances can help control a grease’s consistency.
When looking at the different lubricants used for ball screws, there are two main mediums with varying usage factors. It’s best to follow the manufacturing suggestions on your machine load assembly and have the engineering team monitor the assembly parts closely for signs of application demands.