When selecting positioning stages, one of the first items you’ll have to consider is the driving mechanism. Depending on your application, the driving mechanism you choose can greatly influence your machine’s performance. The previous blog post in this series covered linear stages, and this post will discuss another driving element available with precision stages: the ball screw.
How Ball Screw Driven Stages Work
As the name suggests, a ball screw drive positioning stage is a precision linear component with a ball screw as its drive mechanism. A recirculating ball screw nut travels on a rotating threaded shaft with minimal friction, allowing the ball screw to support heavy axial loads. The assembly of the ball screw nut guided by a linear motion rolling guide acts as a slide table and travels along the helical raceway on the rotating shaft, converting the rotary motion of the ball screw shaft to linear motion. IKO’s slide table has large-diameter steel balls, arranged in two rows that make four-point contact with the Gothic arch raceways, which allow the unit to maintain high accuracy even under a fluctuating or complex load. With the minimal rolling resistance of the IKO linear motion rolling guide, the actuator offers high thrust capability and efficiency typically over 90 percent.
Many ball screw stages have a U-shaped track rail, which under moment load and torsion bolsters rigidity. This U-shaped track rail can be used as a structure beam for the machine it will be designed into to offer engineers greater flexibility. Some U-shaped positioning tables come in lightweight, low-profile models that still maintain high precision despite their small size thanks to high-strength aluminum alloy and special grooves for mounting sensors.
IKO International offers a diverse line of ball screw driven stages in many styles and options. Product benefits and highlights include:
Long strokes. Stage widths range from 15 to 420 millimeters, and stroke lengths can reach up to 1,400 millimeters.
High accuracy and rigidity. The tables and beds are made of cast iron and provide high rigidity and excellent vibration damping. For added stability, accuracy and load capacity, certain IKO models feature integrated linear motion rolling guides arranged in parallel.
Compact size/micro positioning. IKO’s lineup includes small and ultra-small tables with low sectional heights and narrow widths that also deliver high accuracy for applications requiring fast acceleration and deceleration as well as good anti-creep characteristics. Some micro-sized tables can accommodate tiny limit sensors without altering their external dimensions.
Special environments. Certain IKO positioning stages are made specifically for harsh environments, such as those subject to washdowns, and they can satisfy ISO Class 3 (U.S. Fed. Std. 209E Class 1) cleanroom requirements. Optional covers prevent dust contamination.
Maintenance free. Most IKO positioning tables include C-Lube technology inside the ball screw and the linear motion rolling guides. The impregnated lubrication oil in C-Lube is supplied directly to the rolling elements in addition to the prepackaged grease, enabling long-term, maintenance-free operation.
Custom units and additional options. Depending on the application requirements, IKO can offer customized positioning stages with non-standard stage lengths, ball screw types, motor and sensor options, plus flange-type slide tables with bridge covers, brackets and surface treatments and finishes. IKO’s positioning stages with proper coupling and motor brackets can also be driven with various types of rotational motors.
IKO Precision Ball Screw Stages Satisfy Diverse Requirements
Whether you require a slim, compact or lightweight stage, or one built to provide high rigidity, long strokes or harsh environments, IKO can meet your needs with a broad range of ball screw positioning stages plus custom units and accessories. With careful selection and IKO quality and expertise, there’s a stage that will perform in your equipment for a long time.
For more information about IKO precision stages, visit our mechatronics site.