A lead screw is a screw which translates rotary motion into linear motion. Normally used as the driving mechanism in horizontal or vertically driven applications aided by linear guides for supports. They are described by diameter and pitch or lead. The pitch or lead is the amount of travel you get, or distance the nut travels along the screw for every complete revolution. They can be operated manually or motorised.
In general it is best to support the ball screws with our ball screw support units (L1388 to L1406) with a fixed end (generally where the motor is mounted) and a floating (support) end. The support units are selected to suit the loads likely to be required, the size of the ball screw (especially its core diameter) and the type of mounting required. Details of the machining required for each end of the ball screw are shown in the bearing mounts technical section.
As specialists in linear motion systems we offer you a choice of materials and sizes. So whether you need lightweight aluminium rails for use in aviation applications or stainless steel components for when exposure to water or corrosive chemicals is a factor, our knowledgable technical engineers are always on hand to provide assistance.
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Stainless steel trapezoidal lead screws (316 s/s). TR threads 10 to 70mm. Standard right hand threads.
Easy to install. Allows for some misalignment at installation. Compact system, small footprint compared to other rail systems. Preload adjustable by hand.
Although it can take very large loads it cannot take anywhere near as much load as the linear guideways rail system.
Cheaper alternative to the compact rail. Use of T and U rails allows for misalignment at installation. Preload adjustable by hand.
Available in AISI 316L stainless steel suitable for use in applications requiring a high level of corrosion resistance, including sea water.
Cannot take as much load as other systems. Not suitable for moment loads.
Can take extremely high loads including moment loads. Very smooth in operation.
Must be aligned very accurately which costs time and money preparing the mounting surface properly.
Available in a range of materials and sizes. A length of shaft bar is typically cheaper than the cost of an equivalent size precision linear rail.
A larger diameter shaft would be required when there are long lengths and high loads involved compared with the size of an equivalent shaft support rail you would need. This is because they would only be supported at the ends and the shaft ends could bend in the middle if the diameter was too small.
Shaft support rail systems have a shaft support along the full length so are less likely to flex.
Similar to linear guideways, must be aligned very accurately otherwise any mis-alignment may cause the system to ‘snatch’.
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Our technical support engineers can also provide assistance with choosing the right joint or linkage components for your application.