The stationary and rotating parts.
The stator is stationary; the rotor turns. Magnetic interaction between them produces torque on the shaft. Bearings support the rotor while permitting rotation.
Windings create magnetic fields when current flows. The rotor field may come from induced currents, permanent magnets or supplied windings, depending on the motor.
Follow the energy path.
- Electrical inputSupplies the motor.
- Magnetic interactionProduces turning effort.
- Shaft outputDrives the connected load.
A changing field sustains rotation.
In a three-phase AC motor, suitably arranged windings and phase-shifted currents create a rotating magnetic field. Frequency and pole count determine its rotational speed.
The rotor’s relationship to that field depends on motor type. The next two lessons separate induction motors from permanent-magnet synchronous motors.
Rotation can move different machinery.
A traction motor turns the drive sheave, directly or through gearing. A hydraulic power-unit motor drives a pump, which supplies fluid to the lifting circuit.
The motor shaft speed is not automatically the car speed. Gearing, sheave size, roping or hydraulic flow connects one to the other.
Torque, speed and temperature all matter.
A motor must meet the load’s requirements through starting, travel and stopping. Producing torque at low speed can still create considerable heat.
Motor, drive, controller and brake have distinct roles. Understanding a motor does not make every motor interchangeable: supply, cooling, duty and mechanical fit also matter.
A closer look
When the machinery drives the motor and electromagnetic torque opposes rotation, energy can flow from the shaft into the electrical system. This generating operation is developed later in the module.
Check your understanding
Does a motor’s rated power alone tell you how fast the lift car travels?
Reveal the explanation
No. Motor speed and the connected mechanical or hydraulic arrangement determine car movement. Power alone does not specify either.