412LXR Series Product Manual
Appendix A – Understanding Linear Motors
44
Aluminum Cap /
Mounting Plate
(Houses Backiron and
Coil Assembly)
Backiron
Coil Assembly
Thermal Sensors built
into Coil Assembly
Rare Earth Magnets
“Single Row”
Iron Plate
Hall Effect Sensors
mounted to Housing
Advantages/Disadvantages of Slotless Linear
Motors
•
Lower Weight Magnetic Rail: Since this is a single magnet rail the weight is less then half of dual
magnet rail motors. This means less load and higher throughput in multi-axis systems.
•
Structurally Strong Forcer: With the body of the forcer being made of aluminum and the windings
being bonded to this housing, the strength of the forcer is much greater than that of the epoxy only
housed motors. Thus reducing the possibility of motor fatigue failures.
•
Light Weight Forcer: Because of its aluminum body construction, the slotless linear motor forcer weight
is approximately 2/3 that of an equivalent iron core linear motor. Thus resulting in higher throughput in
light load applications.
•
Lower Attractive Forces: The slotless design has a “backiron” causing attractive forces between the
forcer and the rail. However, this attractive force is significantly less than other linear motors. Thus
significantly reducing loading on the linear guide bearings and increasing bearing life.
•
Lower Cogging: Due to the larger magnetic gap between the magnets and forcer “backiron” the slotless
design has lower cogging. This enables the slotless design to operate in applications that require very
good velocity control.
•
Heat Dissipation: The slotless design, with the coil resting across the “backiron”, which is in direct
contact with the aluminum housing, has very good heat transfer characteristics and is easy to manage.
