Determining Thrust Force - Rockwell Automation MagneMotion QuickStick HT User Manual

Determining Thrust Force

The thrust obtainable from a QuickStick HT motor is dependent on several operational param-
eters, including the length of magnet array engaged by the stators, the magnitude of the stator
drive current, and the gap between the magnet array and stators. Further, the allowable magni-
tude of the stator drive current is limited by thermal considerations. Thus the obtainable thrust
can be impacted by ambient temperature or the duty cycle of the drive current.
Laboratory measurements of the thrust that is obtained with a QuickStick HT motor at a vari-
ety of operational parameter values were used to derive a model describing the thrust pro-
duced. The thrust that is produced roughly varies with each of the operating parameters as
follows.
• The thrust that is produced varies roughly in proportion to the length of magnet array
engaged by stators. For example, an 8 cycle long magnet array yields twice the thrust
of a 4 cycle array, assuming that both arrays are fully engaged by stators, with the
same drive current and gap values (see
• The thrust that is produced varies roughly in proportion to the stator drive current (for
example, a drive current of 5 A yields approximately twice the thrust that is obtained
with a drive current of 2.5 A, assuming the same magnet array engagement and gap).
• The thrust that is produced decreases roughly in an exponential fashion as the gap
between the motor and the magnet array is increased (see
The model equation that describes the thrust that a QuickStick HT motor produces with a high
flux magnet array is:
Thrust (N) = (((-0.209 * I
Thrust (Lb) = ((((-0.209 * I
Where:
NumCycles – The length of the array that is engaged by the stators, in cycles (from 2
to 8 cycles) (a cycle for the QuickStick HT is 120 mm).
I – The stator current, in Amps.
stator
PhysGap – The distance from the top of the stator to the bottom of the magnet array,
in mm (from 4 mm to 22 mm).
Thrust – The force produced.
QuickStick HT User Manual
2
) + (35.04 * I
stator
cles
2
) + (35.04 * I
stator
Cycles) / 4.4482
Rockwell Automation Publication MMI-UM007F-EN-P - September 2020
Data for Transport System Design Calculations
Figure A-2).
Figure
(-0.056 * PhysGap)
)) * EXP
stator
(-0.056 * PhysGap)
)) * EXP
stator
Appendix
A-3).
) * NumCy-
) * Num-
321