The design and manufacturing of the ball screw assembly is critical for performance and efficiency, another critical factor to consider is ball screw support. There are three basic considerations, and those include fixed-end, free-end, and support-end.
As with all aspects of this type of system, mismatching or choosing the incorrect type of support has short and long-term implications with the performance of this component as a linear actuator.
Supported Option
The supported-end options for ball screws are used when the ball screw uses one focal point. It is a highly compact type of support that is also going to include a lower cost. The design of this type of a ball screw support is designed to assist the ball screw in resisting or not moving when bending pressures are applied to the system. It is possible for a ball screw to be supported at both ends, or fixed at one end and supported at the other.
Fixed Option
Like the supported option, a ball screw can be fixed at one end and supported at the other as well as fixed at both ends. Unlike the support option, it can also be fixed at one end and free at the other. This last option is not as commonly used as it limits the ability of the ball screw to resist bending when force is applied.
With both ends fixed, the greatest amount of rigidity is available through the ball screw. This allows for faster speed with the increased rigidity, but it also removes any options for the end of the screw to move if thermal expansion is a consideration.
Free Option
With one end free and not actually supported, installation is much easier. However, the big drawback to consider is the loss in critical speed and the increased risk in buckling.
Generally, the fixed and free ball screw support combination is only used for short ball screws and very low operational speed.
