Topology
Double-sided linear induction motors
Two powered primaries work across one conductive fin. A compact option where thrust, track width and moving mass matter.
Two active faces
A DSLIM places a primary on each side of a bare aluminium or copper fin. Unlike a conventional single-sided plate, the fin needs no steel backing.
Both faces contribute thrust. Any comparison with a single-sided motor must use comparable current, air-gap and thermal limits; two active faces do not guarantee twice the complete-system performance.
Forces, gap and alignment
- Normal forces: these can balance on a centred fin in a symmetric arrangement. The frame must still resist the opposing magnetic loads.
- Alignment: the fin must remain within the running-clearance allowance throughout the route.
- Gap: a smaller gap generally improves electromagnetic performance but demands tighter guidance.
- Rating: check thrust across speed, drive current and repeated-duty temperatures—not just a peak.
Choosing the layout
| Design choice | Double-sided | Single-sided |
|---|---|---|
| Reaction plate | Bare conductive fin, driven from both faces. | Conductive plate, usually steel-backed, driven from one face. |
| Mounting | Light passive rail; a frame supports two primaries. | No second-primary frame; the support carries one-sided magnetic pull. |
| Typical fit | Useful for width-limited, high-thrust duties. | May suit a simpler mounting envelope. |
Axis compares the complete installation, including rail mass and cost, available space, guidance, drive requirements and duty cycle. Neither layout is universally best.
Typical applications
- People movers and transit with frequent starts and gradients.
- Launch systems, including rides and test sleds.
- Maglev propulsion and industrial handling.
The selected layout is assessed with motor models, route simulation and thermal checks. Thrust is independent of wheel grip, but load, gap and supply limits still govern performance.
Is double-sided the right fit?
Share the route, speed profile, gap and mounting envelope.