Passenger lifts make movement easy. You don't have to pull yourself through flights of stairs in order to reach your destination. If you are looking for a good passenger lift for your residential or office building, it would definitely help to be aware of the different types so that you can choose the right lift.
Based on the technology used for lifting, lifts are of two types - traction lifts and hydraulic lifts. Both these types of lifts are powered by electricity and fulfill the purpose of moving people up and down buildings. However, they differ on several fronts, besides the technology used. When compared to traction lifts, hydraulic lifts are slower. They cannot lift passenger cars as high as the traction lifts can.
Hydraulic lifts
Hydraulic lifts use hydraulic fluid power to work. An electric pump pumps hydraulic fluid into a jack which pushes a piston located at the base of the lift. The lift moves up and down supported on the piston. Hydraulic lifts cannot be used in buildings that are more than six storeys tall.
The piston used to lift the passenger cab in hydraulic lifts can either be telescopic or non-telescopic. Telescopic pistons elongate like a telescope while the non telescopic pistons have a single cylinder assembly.
Hydraulic lifts can be sub-classified into two types - lifts with holes at the base of the cavity and lifts without holes at the base of the cavity.
In hydraulic lift, holes are provided at the bottom of the lift cavity in order to house the telescopic piston that lifts the lift upwards. A shallow hole is provided below the lift pit for this purpose. These lifts can be used to transport passengers up to a height of 60 ft.
Hydraulic lifts without holes have a pair of pistons fixed on either sides of the passenger cab. There is no need of the shallow hole to be provided under the lift pit. The twin pistons, fixed at the bottom of the pit, lift the cab together. These hydraulic lifts cannot lift cabs above a height of 50 ft.
Traction lifts
Traction lift follows the principles of traction and weight balance. In this technique, the capsule meant to house passengers is counterbalanced in weight by another load of equal weight. The two components are connected with the help of sturdy sheaves and rope arrangement.
As the lift moves up and down, the other load moves correspondingly in the opposite direction and balances the lift. For high rises and for any building that has more than six to eight storeys, traction lifts are used.
Traction lifts are also of two types - geared and gearless. Lifts with gears consist of a gear box attached to the electric motor that powers the machine. The gears drive the wheel over which the rope with cab on one end and counterbalancing weight on the other end are fixed. In other words, the electric motor does not drive the wheel directly. In gearless traction lifts, the electric motor is directly connected to the wheel.
Geared traction lifts can elevate a passenger car up to 250 ft while gearless lifts can lift up to a height of 2000 ft. in terms of speed, gearless traction lift is more powerful since it can move at a speed of 2000 ft per minute. Geared lifts have a speed limit of 500 ft per minute.
You can decide on the type of lift based on the height of the building, speed requirements and other factors.
