When your design or assembly calls for a positioning stage, the first place to begin your selection will be the table’s driving mechanism. For precision positioning stages with a linear motion rolling guide, two common driving technologies that reside between the bed and slide table are a linear motor or ball screw. Each type has attributes that can make it desirable for certain applications. This blog post will provide an overview of linear motor driven positioning stages, and the next post in this series will cover ball screw driven positioning stages.
Linear stages are known for their high speed, accuracy, repeatability and compact size, making them particularly suitable for use in pick-and-place machines and assembly systems used in electronics and semiconductor manufacturing. Their high thrust forces result in high acceleration and deceleration rates.
How Linear Positioning Stages Work
The integrated motor consists of a moving field coil and a C-shaped yoke set between two stator magnets. This arrangement follows Fleming’s Left-Hand Rule, in which the magnetic flux vertically exerted by the magnet and rotational flux generated around the coil by the current forces the coil to move in a horizontal direction. The coil current is switched to a direction that corresponds to the flux direction, producing a continuous driving force. Integrated electronics control the current level, using feedback from a linear encoder, to ensure accurate travel and positioning.
IKO International offers a lineup of precision linear stages with advanced servo technology that deliver many benefits, such as:
- Stability. LT Series linear stages can achieve a high speed stability of ±1.78 percent at 10 mm/second and static stability of ±1 µm or less.
- Long strokes. While the integrated linear motion rolling guide’s track rail can vary, units with super long strokes beyond 2,700 millimeters are available.
- High thrust and high loads. When the moving field coils of a linear motor driven stage are densely arranged, the resulting magnetic fluxes can produce very high thrust forces to position heavy loads.
- Compact size. Integrated neodymium magnets help provide large thrust forces and high-speed response in compact units. One such unit — IKO’s NT38V10 — comes with an 11-millimeter sectional height, 38-millimeter width and 62-millimeter length.
- Maintenance free. Depending on size and series, IKO C-lube linear profile rails can be incorporated into the linear motors to provide maintenance-free operation for five years or 12,500 miles.
IKO Precision Stages for High-Speed Applications
IKO’s LT Series linear stages deliver large thrust forces for fast acceleration and deceleration, good response and high static and speed stability, and the NT Series offers many of the same attributes in a compact size. When your application needs accurate positioning for high-speed linear motion, precision positioning stages with linear motor drive technology are an attractive option.
For more information about IKO precision linear stages, click here.