Direct drive brushless DC servo motor

* Precision ground ABEC-7 4-point contact bearings
* Durable stainless steel top plate with through hole
* Resolution to 0.2 arc seconds
* Highly repeatable Hall effect home and limit switches
* Optional encoder scale cover
* Ideal for:
o Wafer Inspection
o Precision Assembly
o Laser Machining




Low Profile Direct Drive Rotary Stage
Anorad's new DDR-150 rotary positioning stages are designed for precise position and velocity control in light to medium force applications. High performance is achieved through use of a brushless DC servomotor, high resolution optical encoder and precision bearing set all housed in a compact and precisely machined aluminum base with a rugged stainless steel top plate.



The direct drive servo control of the brushless DC motor has several advantages over conventional gear driven rotary stages. Backlash is eliminated, torque variation is minimized, plus gear and brush wear are no longer factors in long term usage. Added benefits include speeds up to 360 rpm, 0.2 arc second resolution and ±1 arc second repeatability. Step-and-settle time is also reduced due to increased servo bandwidth.

Available options for the DDR-150 include a variety of encoder resolutions to meet your speed and accuracy requirements. An axial through hole for use with pneumatic or optical devices; adjustable home, limit and hardstop positions; and a sheet metal cover to protect the encoder and internal components.


Specifications
Parameter Specification Parameter Specification
Travel unlimited Maximum Velocity2 1273 rpm
Accuracy ±20 arc sec Acceleration 34 rad/s2
Repeatability1 (bi-directional) ±1 arc sec Axial Capacity 25 kg
Resolution1 0.214 arc sec Axial Runout (TIR) 5 µm
Stability ±2 counts Radial Runout (TIR) 5 µm
Minimum move1 0.5 arc sec Wobble3 ±8 µm
Peak Torque 7.4 Nm Thru Hole diameter 35 mm
Continuous Torque 1.4 Nm Concentricity (Thru hole) ±2 µm
Inertia
0.217 kg-m2 Stage Weight 3.5 kg


DDR-150 Construction Mechanical Features
Stationary Base High strength aluminum alloy with black anodized finish (Nickel plating optional)
Rotating Table
Stainless steel with passivated finish
Bearing System
ABEC-7 precision ground 4-point contact radial bearing
Encoder
Incremental optical encoder with reflective tape scale (50 lines/mm)
Limit Switches Hall effect home and limit switches





1. With 0.214 arc sec resolution (256x multiplication)
2. At lowest resolution (top speed dependent on controller and resolution)
3. Measured at 60mm radius