Glossary · Motion control and drives
Direct drive
Also known as: Gearless drive
German: Direktantrieb
In motion control, a direct drive is a drive arrangement in which the motor is connected to the load without a gearbox, belt or screw, so the motor's rotor or forcer moves the load directly. Torque motors and linear motors are typical direct drives.
- Motion control
In one sentence
A direct drive moves the load without gearbox, belt or screw; torque motors and linear motors are typical examples.
Example
A rotary indexing table driven by a torque motor needs no gearbox and positions more precisely because there is no backlash.
How it applies
- Engineering: Without transmission, there is no backlash or gear wear, and stiffness and dynamics improve. But the load inertia acts directly on the motor, so the control loop and encoder resolution become more critical.
- Commissioning: Direct drives need careful loop tuning; resonances of the machine structure show up directly in the control.
- Maintenance: Fewer wear parts, but strong permanent magnets and high forces require specific handling instructions.
- Documentation: Warn about magnetic fields (for example for people with pacemakers) and pinch hazards from magnetic attraction during assembly. Explain that a direct-driven vertical axis without a gearbox has no self-locking and needs a brake or counterbalance.
Direct drive vs. geared drive
A geared drive trades speed for torque and decouples load inertia from the motor. A direct drive avoids the gearbox's backlash, wear and lubrication, but needs a motor sized for the full load torque.