Question

List and explain in details ALL of Traction Lift components with complete schematic.(10mrks)

Answer 1

What is a Traction lift?

The lift is a type of vertical transport equipment that efficiently moves people or goods between floors (levels, decks) of a building, vessel or other structure. generally powered by electric motors that either drive cables.

Principle : see – saw

Working:-

The car is raised and lowered by traction steel ropes rather than pushed from below. The ropes are attached to the elevator car, looped around a sheave &connected to an electric motor. When the motor turns one way, the sheave raises the elevator; when the motor turns the other way, the sheave lowers the elevator. Typically, the sheave, the motor and the control system are all housed in a machine room above the elevator shaft. The ropes that lift the car are also connected to a counterweight, which hangs on the other side of the sheave. The counterweight and the car are perfectly balanced. Basically, the motor only has to overcome friction -- the weight on the other side does most of the work. In gearless elevators, the motor rotates the sheaves directly. In geared elevators, the motor turns a gear train that rotates the sheave. Nowadays, some traction elevators are using flat steel belts instead of conventional steel ropes. Flat steel belts are extremely light due to its carbon fiber core and a high-friction coating, and does not require any oil or lubricant.

A schematic diagram showing various component of a traction lift is:-

1- Control system.

Various components of a Traction lift:-

Control system - to Electronically control the whole arrangement - for automated.

Electric Motor

• a pulley with a grooves around the circumference.
• grips the hoist ropes, so when you rotate the sheave, the ropes move too.Sheave
• Sheave rotates with the help of motor.

Counter weight or balance-weight - A unit, consisting of steel weights, which counter balance the weight of the car and a portion of the load, and to which the suspension ropes are attached.

• hangs on the other side of the sheave.
• it weighs about the same as the car filled to 40-percent capacity.
• Connected with the ropes

Guiding rail - These, fixed truly vertical in the shaft, are of steel and serve to guide the movement of both car and counterweight.

• Are along the sides of the elevator shaft.
• keep the car and counterweight from swaying back and forth.
• also work with the safety system to stop the car in an emergency.

Elevator car - That part of an elevator that includes the platform, enclosure, car frame, and door.

Machine beam - A steel beam, positioned directly over the elevator in the machine room and is used to support elevator equipment.

Machine room - This usually located at the top of the shaft and accommodates the winding machine, etc.

Pit - That part of an elevator shaft that extends from the threshold level of the lowest landing door down to the floor at the very bottom of the shaft.

Shaft - A hoistway through which one or more elevator cars may travel.

Trailing cable - Flexible cable providing electrical connection between the lift car and a fixed point or points.

Bottom clearance - The distance, including buffer compression, the platforms could travel below the bottom landing until the full weight of the car, when loaded, rests on the buffer.

Top clearance - The vertical distance between the top car attachment and the bottom of the diverting pulley or any steelwork supporting equipment; there must be an adequate margin between this and the car will not contact the diverting pulley or steelwork.