Frameless Servos – Rugged, Robust and Reduced Length of Stage
Servo motors play an important role in many industries. Its application areas are diverse and crucial; from robots to flying machines and from core industries such as paper, textile & heavy engineering to scientific equipments. Servo motors are available as frameless or with a frame.
Frameless servos are motors without housingor a frame. It consists of all the regular components of a standard motor such asa rotor equipped with magnets, a stator encapsulated with copper wiring and a sensor mounted on it. An encoder also forms a part of this setup. The only missing component is the housing.
It is frameless motor which is used for special applications.
As with the standard servo motor, even this one runs by energizing the stator windings to create rotating magnetic field which turns the motor shaft. While the housing is absent,a frameless servo consists of other parts such as internal encoder, ball screw shaft, thrust bearing, magnets attached to ball screw shaft etc.
Mentioned below are some of its advantages of frameless servo.
1. Frameless servo does not require a coupler which effectively reduces the length of the stage.
2. The accuracy and the performance of the ball screw are greatly enhanced due to the absence of the coupler.
3. The feedback device and the motor are attached directly to the ballscrew shaft.
4. Frameless motor stages typically achieve shorter settling times.
5. Frameless motor stages are far more robust and rugged.
A servo motor consists of four core components: a motor, gear unit which typically produces variable speeds, a potentiometer which senses the position of the shaft and anelectronic controller.
Servo control receives signal in the form of pulse which dictates the desired position of the servo shaft. This in turn provides a consistent power to motor until the desired position of the shaft is attained.
This shaft typically moves horizontally, around 180 degrees. As mentioned above, a servo motor has a potentiometer and a control unit to provide feedback, which is typicallyconnected to the output shaft. The potentiometer along with the control unit monitors the current angle of the shaft.