Configurations
Linear motors come in three configurations. These are U-channel, flat-type, and cylindrical (tubular). Voice coil motors can also generate linear motion; they are made in different geometries as well. The linear motors have different characteristics because of the configurations, in force magnitude, speed, acceleration / deceleration, motion smoothness, leakage field, and cost.
Dexter can design, manufacture and deliver custom linear motor solutions.
Cylindrical
• 3-phase windings typically, with brushless commutation using Hall effect sensors
• Magnetic leakage: Medium-High
• Points of support: Only at both ends
• Limit of length due to deflection
Flat
• Ironless flat motors – smooth velocity control
• Slotless-iron flat motors – for higher force output
• Slotted-iron flat motors – for even higher force output
• Cogging force can be reduced by skewed magnets
Attractive force between “forcer” and magnet track can be used advantageously as preload
U-Channel
• Two parallel magnet tracks facing each other, seated in U-shaped channel
• “Forcer” (coil windings) supported by bearings between magnet tracks
• Typically 3-phase, w/ brushless commutation
• Forcer is ironless; low mass; high acceleration; smooth linear motion
• Magnetic leakage: Low
Can be staged to increase length of travel