How Commercial and Residential Elevators Work: Mechanisms That Make Our Lifts Move
How Commercial and Residential Elevators Work
You may be surprised to learn that not all elevators operate in the same fashion. In fact, there are many different mechanisms used in elevators to raise and lower their cabs. Each has its own benefits, and each can be appropriate for different uses.
A popular choice for commercial elevators in public buildings up to five floors, this type of lift uses two hydraulic jacks attached to the bottom of the cab that are powered by a pump in a nearby room.
Chained Traction Drive
Commonly found in residential elevators, a chained traction drive operates using an electric motor and gearbox to raise and lower the elevator car with a chain. The car is offset by counterweights, and the motor can be found at the top of the rail system that keeps the car in place.
Used in both residential and commercial lifts, a screw drive uses a drive nut and screw shaft to move the platform up and down. A screw drive is considered a relatively slow method, and for that reason, it’s usually only used for vertical distances of 6 feet or less, like in residential lifts for wheelchair users.
This approach combines cables and a hydraulic jack to raise and lower the cab. This combination creates a smooth ride in passenger elevators without the need to dig a deep hole for the jack.
Commonly seen in a wheelchair lift, a chained hydraulic system uses a hydraulic jack and chains working together to raise and lower a platform. It’s faster than a screw drive, and for this reason, it’s the preferred choice for heights of more than 6 feet.
Roped Hydraulic LULA
This type of elevator is used for adding accessibility to buildings of two to three floors. It operates by adding a pulley to the top of a jack and using two hoisting cables to connect it all together.
Winding Drum Drive Below/Above
Popular in residential elevators, this method uses a drum that winds cables attached to the cab in order to move it up and spools out the cables in order to lower it. The drum is placed either at the top or bottom of the hoistway.
Pneumatic elevators work by using a difference in air pressure to raise and lower the cab. Air is pumped out of the upper section of the hoistway to create a vacuum, pulling the cab upward. When the air is slowly let back in, the cab is lowered.
For a more detailed look at how these systems work, check out our educational videos