Traction elevators
Best for: Mid-to high-rise buildings.
How they work: A traction elevator operates using steel ropes that are attached to the car and wrapped around a grooved pulley called a sheave. An electric motor rotates the sheave, pulling the car up or down.
Counterweight: A counterweight is attached to the other end of the ropes. It balances the weight of the car and reduces the amount of energy the motor needs to lift the load.
Types:
Geared traction elevators use a gearbox connected to the motor, which is common for medium-speed applications.
Gearless traction elevators have the motor and sheave directly connected, allowing for much higher speeds suitable for high-rise buildings.
Machine-room-less (MRL) elevators are a type of traction elevator where all components, including the motor, are placed within the elevator shaft itself, eliminating the need for a separate machine room.
Hydraulic elevators
Best for: Low-rise buildings, typically 2 to 8 stories.
How they work: An electric pump injects hydraulic fluid into a cylinder, which extends a piston to lift the elevator car. To descend, a valve releases the fluid, and the car lowers itself.
