Servo motors are classified primarily on their current type; whether they utilise an alternating or direct current (AC/DC). AC-servo motors control rotation as a function of frequency, while in DC motors, rotation speed is directly proportional to the input voltage. The self-contained motor may also be classified as brushed or brushless, which determines whether the rotation is conducted mechanically with a commutator or electronically without. Learn more »
There is a diverse range of servo positioning stages available utilizing various design types and component options. For screw-driven positioners, lead screw or ball screw drives are generally employed. Lead screws can provide higher resolution and holding forces while ball screws provide improved throughput with higher speed capabilities and reduced friction. Screw-less linear stages can be driven by 3-phase linear motors or single-phase voice coil motors for short ranges. At PI, we provide servo positioners travel ranges of 5 – 1016mm (1/5” to 40”) and longer stage travel ranges upon request.
Our miniature servo positioners provide resolutions down to the single digit nanometer range and linear motor driven positioning stages can actually provide ½ nm steps as shown below.