WEISS HP140, Руководство по эксплуатации

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WAS.handling Electro Documentation
34
4.3 Mechanics, Motors and Feedback
The mechanics consists of two linear motors which are coupled to Y/Z-axes. The use of linear motors gives an
increase of dynamics. With less load (up to 1.5kg), accelerations up to 40m/s² are possible which however
going back with increasing load. The maximum linear speed is 4m/s.
The motors are internal development. A patented winding technique holds the temperature low. The motor is
optimized to a minimum engaging. It is protected by a temperature sensor (PTC-Switch) in the winding as well
as extensive calculation models in the drive.
As measuring system, a robust magnetic length measuring system is used. The magnetic division of poles is
1mm. The interpolation of the Acopos-drive is by factor 4096, what an electrical resolution of 0.244µm yields.
The used measuring system belongs to the family of the incremental measuring systems. Because off this, the
motor phase (commutation) and the reference position must be found after each Power ON.
Motor commutation:
With the first enablement of the axis after Power ON the drive automatically searches the motor commutation.
For this, the drive gives a frequency model onto the axis and is calculated from the encoder signal the motor
commutation. You hear this at the short "humming" (like a buzzer).
The usual method to find the motor commutation is the so called “frequency method” with the disadvantage
that the axis must swing freely for this. Is the axis blocked or is the linear axis at the left or right limit, this
method calculates a wrong motor commutation without an alarm. Therefore, we are using drives which are
using the reluctance method. This gives a correct result independent to whether the axis is free or blocked.
However, this method is only offered by few manufacturers.
Y+
Z+